U.S. patent application number 13/790206 was filed with the patent office on 2013-09-19 for undercoat agent and method of forming pattern of layer containing block copolymer.
This patent application is currently assigned to TOKYO OHKA KOGYO CO., LTD.. The applicant listed for this patent is TOKYO OHKA KOGYO CO., LTD.. Invention is credited to Tsuyoshi Kurosawa, Tasuku Matsumiya, Ken Miyagi, Kenichiro Miyashita, Katsumi Ohmori, Takahiro Senzaki, Daiju Shiono.
Application Number | 20130243958 13/790206 |
Document ID | / |
Family ID | 49157893 |
Filed Date | 2013-09-19 |
United States Patent
Application |
20130243958 |
Kind Code |
A1 |
Senzaki; Takahiro ; et
al. |
September 19, 2013 |
UNDERCOAT AGENT AND METHOD OF FORMING PATTERN OF LAYER CONTAINING
BLOCK COPOLYMER
Abstract
An undercoat agent which is used for phase separating a layer
including a block copolymer having a plurality of blocks bonded
formed on a substrate, wherein the undercoat agent contains a resin
component, the resin component includes a structural unit having an
aromatic ring and a structural unit having no aromatic ring, and
the resin component includes a group which can interact with the
substrate and does not include a 3 to 7-membered, ether-containing
cyclic group; and a method of forming a pattern of a layer
containing a block copolymer, including: a step (1) in which the
undercoat agent is applied to a substrate to form a layer
containing the undercoat agent; a step (2) in which a layer
containing a block copolymer having a plurality of blocks bonded is
formed on a surface of the layer containing the undercoat agent,
followed by a phase separation of the layer containing the block
copolymer; and a step (3) in which a phase containing at least one
block of the plurality of blocks constituting the block copolymer
is selectively removed.
Inventors: |
Senzaki; Takahiro;
(Kawasaki-shi, JP) ; Miyagi; Ken; (Kawasaki-shi,
JP) ; Kurosawa; Tsuyoshi; (Kawasaki-shi, JP) ;
Shiono; Daiju; (Kawasaki-shi, JP) ; Matsumiya;
Tasuku; (Kawasaki-shi, JP) ; Miyashita;
Kenichiro; (Kawasaki-shi, JP) ; Ohmori; Katsumi;
(Kawasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOKYO OHKA KOGYO CO., LTD. |
Kawasaki-shi |
|
JP |
|
|
Assignee: |
TOKYO OHKA KOGYO CO., LTD.
Kawasaki-shi
JP
|
Family ID: |
49157893 |
Appl. No.: |
13/790206 |
Filed: |
March 8, 2013 |
Current U.S.
Class: |
427/264 ;
524/544; 524/547; 524/549; 524/555; 524/556; 524/562 |
Current CPC
Class: |
C09D 133/08 20130101;
C09D 125/14 20130101; C09J 133/14 20130101; C09D 125/02 20130101;
C09D 133/22 20130101; C09D 133/18 20130101; C09J 133/06 20130101;
B05D 3/145 20130101; C09D 133/02 20130101; B05D 7/544 20130101;
C09D 135/06 20130101; C09D 143/04 20130101 |
Class at
Publication: |
427/264 ;
524/556; 524/555; 524/562; 524/547; 524/544; 524/549 |
International
Class: |
C09D 143/04 20060101
C09D143/04; C09D 135/06 20060101 C09D135/06; C09D 133/08 20060101
C09D133/08; C09D 133/02 20060101 C09D133/02; C09D 133/22 20060101
C09D133/22 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 14, 2012 |
JP |
2012-057693 |
Feb 5, 2013 |
JP |
2013-020932 |
Claims
1. An undercoat agent which is used for phase separating a layer
including a block copolymer having a plurality of blocks bonded
formed on a substrate, wherein the undercoat agent comprises a
resin component, the resin component includes a structural unit
having an aromatic ring and a structural unit having no aromatic
ring, and the resin component includes a group which can interact
with the substrate and does not include a 3 to 7-membered,
ether-containing cyclic group.
2. The undercoat agent according to claim 1, wherein an amount of
the structural unit having an aromatic ring, based on the combined
total of all structural units constituting the resin component is
10 to 95 mol %.
3. The undercoat agent according to claim 1, wherein the group
which can interact with the substrate is a carboxy group, a cyano
group, an amino group or a trimethoxysilyl group.
4. The undercoat agent according to claim 1, wherein the structural
unit having an aromatic ring is a structural unit derived from a
compound selected from the group consisting of an aromatic compound
which contains a vinyl group and has 6 to 18 carbon atoms, an
aromatic compound which contains a (meth)acryloyl group and has 6
to 18 carbon atoms and a phenolic compound which is a component of
a novolac resin.
5. The undercoat agent according to claim 1, further comprising an
acidic compound component or an acid generator component that
generates acid upon heating or exposure.
6. A method of forming a pattern of a layer containing a block
copolymer, comprising: applying the undercoat agent of claim 1 to a
substrate to form a layer comprising the undercoat agent; forming a
layer containing a block copolymer having a plurality of blocks
bonded on a surface of the layer comprising the undercoat agent,
followed by a phase separation of the layer containing the block
copolymer; and selectively removing a phase comprising at least one
block of the plurality of blocks constituting the block
copolymer.
7. The method of forming a pattern of a layer containing a block
copolymer according to claim 6, wherein an amount of the structural
unit having an aromatic ring, based on the combined total of all
structural units constituting the resin component is 10 to 95 mol
%.
8. The method of forming a pattern of a layer containing a block
copolymer according to claim 6, wherein the group which can
interact with the substrate is a carboxy group, a cyano group, an
amino group or a trimethoxysilyl group.
9. The method of forming a pattern of a layer containing a block
copolymer according to claim 6, wherein the structural unit having
an aromatic ring is a structural unit derived from a compound
selected from the group consisting of an aromatic compound which
contains a vinyl group and has 6 to 18 carbon atoms, an aromatic
compound which contains a (meth)acryloyl group and has 6 to 18
carbon atoms and a phenolic compound which is a component of a
novolac resin.
10. The method of forming a pattern of a layer containing a block
copolymer according to claim 6, further comprising an acidic
compound component or an acid generator component that generates
acid upon heating or exposure.
11. The method of forming a pattern of a layer containing a block
copolymer according to claim 6, wherein the structural unit having
an aromatic ring is at least one structural unit selected from
structural units represented by general formulas (a1-1) to (a1-4)
shown below; ##STR00044## wherein R represents a hydrogen atom, an
alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of
1 to 5 carbon atoms; X.sup.c and X.sup.d each independently
represents a hydrogen atom, a hydroxy group, a cyano group or an
organic group; R.sup.c and R.sup.d each independently represents a
halogen atom, --COOX.sup.e (X.sup.e represents a hydrogen atom or
an organic group), an alkyl group of 1 to 5 carbon atoms or a
halogenated alkyl group of 1 to 5 carbon atoms; px represents an
integer of 0 to 3, qx represents an integer of 0 to 5, and px+qx=1
to 5, provided that, when qx is an integer of 2 or more, the
plurality of R.sup.c groups may be the same or different from each
other; x represents an integer of 0 to 3, y represents an integer
of 0 to 3, y' represents an integer of 0 to 2, z represents an
integer of 0 to 4, and in the formula (a1-2), x+y+z=1 to 7, and in
the formula (a1-3), x+y+y'+z=1 to 7, provided that, when y+z or
y+y'+z is an integer of 2 or more, the plurality of R.sup.d groups
may be the same or different from each other; and X.sup.Ar
represents a monovalent organic group containing an aromatic
ring.
12. The method of forming a pattern of a layer containing a block
copolymer according to claim 6, wherein the structural unit having
no aromatic ring is at least one structural unit selected from
structural units represented by general formulas (a2-1) and (a2-2)
shown below; ##STR00045## wherein R represents a hydrogen atom, an
alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of
1 to 5 carbon atoms; X.sup.a and X.sup.b each independently
represents a hydrogen atom or an organic group which does not
contain an aromatic ring; and le represents a hydrogen atom or an
alkyl group of 1 to 5 carbon atoms.
13. The method of forming a pattern of a layer containing a block
copolymer according to claim 8, wherein the structural unit having
no aromatic ring comprises the group which can interact with the
substrate.
14. The method of forming a pattern of a layer containing a block
copolymer according to claim 6, wherein the structural unit having
no aromatic ring is at least one structural unit represented by any
one of formulas (a21-1) and (a21-2) shown below; ##STR00046##
wherein R represents a hydrogen atom, an alkyl group of 1 to 5
carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms;
R.sup.b represents a hydrogen atom or an alkyl group of 1 to 5
carbon atoms; Y.sup.01 represents a single bond or a divalent
linking group which does not contain an aromatic ring; X.sup.01
represents a hydrogen atom, a carboxyl group, a cyano group, an
amino group, a trialkoxysilyl group, a lactone-containing cyclic
group or an organic group containing a fluorine atom, provided
that, when X.sup.01 is a hydrogen atom, Y.sup.01 represents a
single bond, and when X.sup.01 is a carboxy group, a cyano group,
an amino group or a trialkoxysilyl group, Y.sup.01 represents a
divalent linking group which does not have an aromatic ring;
Y.sup.02 represents a divalent linking group which does not have an
aromatic ring; and X.sup.02 represents a carboxy group, a cyano
group, an amino group or a trialkoxysilyl group.
15. The method of forming a pattern of a layer containing a block
copolymer according to claim 6, wherein the structural unit having
no aromatic ring is at least one structural unit represented by any
one of formulas shown below; ##STR00047## ##STR00048## wherein R
represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms
or a halogenated alkyl group of 1 to 5 carbon atoms.
16. The method of forming a pattern of a layer containing a block
copolymer according to claim 15, wherein the structural unit having
an aromatic ring is at least one structural unit represented by
general formula (a1-1) or (a1-2) shown below; ##STR00049## wherein
R represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms
or a halogenated alkyl group of 1 to 5 carbon atoms; X.sup.c and
X.sup.d each independently represents a hydrogen atom, a hydroxy
group, a cyano group or an organic group; R.sup.c and R.sup.d each
independently represents a halogen atom, --COOX.sup.e (X.sup.e
represents a hydrogen atom or an organic group), an alkyl group of
1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon
atoms; px represents an integer of 0 to 3, qx represents an integer
of 0 to 5, and px+qx=1 to 5, provided that, when qx is an integer
of 2 or more, the plurality of R.sup.e groups may be the same or
different from each other; x represents an integer of 0 to 3, y
represents an integer of 0 to 3, z represents an integer of 0 to 4,
and x+y+z=1 to 7, provided that, when y+z is an integer of 2 or
more, the plurality of R.sup.d groups may be the same or different
from each other.
17. The method of forming a pattern of a layer containing a block
copolymer according to claim 6, wherein the amount of the
structural unit having no aromatic ring, based on the combined
total of all structural units constituting the resin component is
preferably 5 to 90 mol %.
18. The method of forming a pattern of a layer containing a block
copolymer according to claim 6, wherein the structural unit having
an aromatic ring is at least one structural unit represented by any
one of general formulas shown below; ##STR00050## wherein R
represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms
or a halogenated alkyl group of 1 to 5 carbon atoms, and the
structural unit having no aromatic ring is at least one structural
unit represented by any one of formulas shown below; ##STR00051##
wherein R represents a hydrogen atom, an alkyl group of 1 to 5
carbon atoms or a halogenated alkyl group of 1 to 5 carbon
atoms.
19. The method of forming a pattern of a layer containing a block
copolymer according to claim 6, wherein the block copolymer is at
least one block copolymer selected from the group consisting of a
polystyrene-polymethyl methacrylate (PS-PMMA) block copolymer, a
polystyrene-polyethyl methacrylate block copolymer, a
polystyrene-(poly-t-butyl methacrylate) block copolymer, a
polystyrene-polymethacrylic acid block copolymer, a
polystyrene-polymethyl acrylate block copolymer, a
polystyrene-polyethyl acrylate block copolymer, a
polystyrene-(poly-t-butyl acrylate) block copolymer and a
polystyrene-polyacrylic acid block copolymer.
Description
TECHNICAL FIELD
[0001] The present invention is related to an undercoat agent which
is used for phase separating a layer including a block copolymer
having a plurality of blocks bonded formed on a substrate, and a
method of forming a pattern of a layer containing a block copolymer
by using the undercoating agent.
[0002] Priority is claimed on Japanese Patent Application No.
2012-057693, filed Mar. 14, 2012, and Japanese Patent Application
No. 2013-020932, filed Feb. 5, 2013, the contents of which are
incorporated herein by reference.
BACKGROUND ART
[0003] Recently, as further miniaturization of large scale
integrated circuits (LSI) proceeds, a technology for processing a
more delicate structure is demanded. In response to such demand, an
attempt has already been started in which a fine pattern is formed
using a phase-separated structure formed by self-assembly of a
block copolymer having mutually incompatible blocks bonded
together.
[0004] For using a phase separation of a block copolymer, it is
necessary to form a self-assembled nano structure by a microphase
separation only in specific regions, and arrange the nano structure
in a desired direction. For realizing position control and
orientational control, graphoepitaxy to control phase-separated
pattern by a guide pattern and chemical epitaxy to control
phase-separated pattern by difference in the chemical state of the
substrate are proposed (see, for example, Non-Patent Document
1).
[0005] One method that has been proposed for achieving favorable
phase separation of a block copolymer, thus enabling formation of a
very fine pattern, is a method in which a neutral layer having a
surface free energy that is between the surface free energy values
of two block chains is formed on the substrate, so that the surface
free energy of the surface on the substrate with which the block
copolymer makes contact is a surface free energy value that is
between the surface free energy values of the two block chains (for
example, see Patent Document 1).
[0006] Further, Non-Patent Document 2 discloses that a method of
forming an under layer film by using a compound having
heat-crosslinkable property.
DOCUMENTS OF RELATED ART
[0007] [Patent Document] [0008] [Patent Document 1] Japanese
Unexamined Patent Application, First Publication No. 2008-36491
[0009] [Non-Patent Documents] [0010] [Non-Patent Document 1]
Proceedings of SPIE (U.S.), vol. 7637, pp. 76370G-1 (2010) [0011]
[Non-Patent Document 2] Proceedings of SPIE (U.S.), vol. 6921, pp.
692127-1-8 (2008)
SUMMARY OF THE INVENTION
[0012] However, in the method disclosed in Patent Document 1, the
surface free energy of the neutral layer must be controlled, with
the material for the neutral layer being selected in each case so
as to have a surface free energy value that is appropriate for the
type of block copolymer being used. Accordingly, an undercoat agent
that can be used in a simpler manner, and enables formation of a
favorable pattern via phase separation of a block copolymer has
been keenly sought.
[0013] Further, an undercoat agent is not needed for a process such
as etching of a substrate, after forming a pattern by phase
separation. Therefore, an undercoat agent is required not only to
have a function of enabling a satisfactory phase separation of a
block copolymer, but also to be capable of forming a thin film
which does not affect a later step or is easily removed. However,
as described in Non-Patent Document 2 which discloses that the film
thickness of the lower-layer film is 5 to 100 nm, crosslinking by
heating causes a problem that the film thickness of the lower-layer
film increases.
[0014] The present invention takes the above circumstances into
consideration, with an object of providing an undercoat agent which
is capable of forming a thin film and which can be used to produce
a substrate provided with a nanostructure on the surface thereof by
phase separation of a block copolymer, wherein the nanostructure is
designed more freely with respect to the positioning and the
orientation thereof; and a pattern formation method for a layer
containing a block copolymer using the undercoat agent.
[0015] As a result of intensive investigation, the inventors of the
present invention discovered that by using an undercoat agent
having a specific resin component for performing phase separation
of a layer containing a block copolymer, a favorable pattern could
be obtained by phase separation without having to control the
surface free energy of the layer composed of the undercoat agent,
and they also found that a layer composed of the undercoat agent
could be formed as a thin film, and they were thus able to complete
the present invention.
[0016] A first aspect of the present invention is an undercoat
agent which is used for phase separating a layer including a block
copolymer having a plurality of blocks bonded formed on a
substrate, wherein the undercoat agent contains a resin component,
the resin component includes a structural unit having an aromatic
ring and a structural unit having no aromatic ring, and the resin
component includes a group which can interact with the substrate
and does not include a 3 to 7-membered, ether-containing cyclic
group.
[0017] A second aspect of the present invention is a method of
forming a pattern of a layer containing a block copolymer, the
method including: a step (1) in which the undercoat agent of the
first aspect is applied to a substrate to form a layer containing
the undercoat agent; a step (2) in which a layer containing a block
copolymer having a plurality of blocks bonded is formed on a
surface of the layer containing the undercoat agent, followed by a
phase separation of the layer containing the block copolymer; and a
step (3) in which a phase containing at least one block of the
plurality of blocks constituting the block copolymer is selectively
removed.
[0018] In the present description and claims, the term "aliphatic"
is a relative concept used in relation to the term "aromatic", and
defines a group or compound that has no aromaticity.
[0019] The term "alkyl group" includes linear, branched or cyclic,
monovalent saturated hydrocarbon, unless otherwise specified. The
same applies for the alkyl group within an alkoxy group.
[0020] The term "alkylene group" includes linear, branched or
cyclic divalent saturated hydrocarbon, unless otherwise
specified.
[0021] A "halogenated alkyl group" is a group in which part or all
of the hydrogen atoms of an alkyl group is substituted with a
halogen atom, and a "halogenated alkylene group" is a group in
which part or all of the hydrogen atoms of an alkylene group is
substituted with a halogen atom. Examples of the halogen atom
include a fluorine atom, a chlorine atom, a bromine atom and an
iodine atom.
[0022] A "hydroxyalkyl group" is a group in which part or all of
the hydrogen atoms within an alkyl group have been substituted with
a hydroxyl group.
[0023] The term "structural unit" refers to a monomer unit that
contributes to the formation of a polymeric compound (resin,
polymer, copolymer).
[0024] The term "exposure" is used as a general concept that
includes irradiation with any form of radiation.
[0025] A "block" is a partial structural component, which is
composed only of the same type of structural unit bonded together,
and constitutes part of a block copolymer.
[0026] The term "(meth)acrylic acid" is a generic term that
includes either or both of acrylic acid having a hydrogen atom
bonded to the .alpha.-position and methacrylic acid having a methyl
group bonded to the .alpha.-position.
[0027] The term "(meth)acrylate ester" is a generic term that
includes either or both of the acrylate ester having a hydrogen
atom bonded to the .alpha.-position and the methacrylate ester
having a methyl group bonded to the .alpha.-position.
[0028] The term "(meth)acrylate" is a generic term that includes
either or both of the acrylate having a hydrogen atom bonded to the
.alpha.-position and the methacrylate having a methyl group bonded
to the .alpha.-position.
[0029] According to the undercoat agent of the present invention,
by using phase separation of a block copolymer, a substrate
provided with a nanostructure on the surface thereof can be simply
produced, wherein the nanostructure is more freely designed with
respect to the positioning and the orientation thereof. Moreover,
when the undercoat agent of the present invention is used, a film
having the aforementioned function can be formed as a comparatively
thin film on the substrate, and therefore the effects of the layer
composed of the undercoat agent on later steps is minimal, and
removal of the layer composed of the undercoat agent is
comparatively simple.
[0030] Further, in the pattern formation method for a layer
containing a block copolymer according to the present invention, by
using the undercoat agent mentioned above, a substrate provided
with a nanostructure on the surface thereof can be produced,
wherein the nanostructure is designed more freely with respect to
the positioning and the orientation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a schematic process diagram explaining an
embodiment of the pattern formation method for a layer containing a
block copolymer according to the present invention.
MODE FOR CARRYING OUT THE INVENTION
Undercoat Agent
[0032] The undercoat agent of the first aspect of the present
invention contains at least a resin component, and is used for
performing phase separation of a layer containing a block copolymer
having a plurality of types of blocks bonded formed on a substrate.
Specifically, by applying the undercoat agent to the substrate to
form a layer composed of the undercoat agent on the substrate,
followed by forming a layer containing a block copolymer having a
plurality of types of blocks bonded on the undercoat agent, the
substrate surface, which has the layer composed of the undercoat
agent formed thereon, is able to exhibit a high level of affinity
for each of the blocks that constitute the block copolymer.
[0033] Descriptions of the phase separation of the layer containing
the block copolymer, and the pattern formation method for the layer
containing the block copolymer, both of which can use the undercoat
agent of the present invention, are presented below within the
description of the second aspect.
[0034] <Resin Component (A)>
[0035] The undercoat agent of the present invention contains at
least a resin component (A) (hereafter, frequently referred to as
"component (A)").
[0036] In the present description and claims, the term "resin
component" refers to a polymer having a molecular weight of 1,000
or more. As the molecular weight of the polymer, the weight average
molecular weight in terms of the polystyrene equivalent value
determined by gel permeation chromatography (GPC) is used.
[0037] The component (A) of the present invention includes a
structural unit (a1) having an aromatic ring and a structural unit
(a2) having no aromatic ring.
[0038] Further, the component (A) of the present invention includes
a group which can interact with the substrate and does not include
a 3 to 7-membered, ether-containing cyclic group. The "group which
can interact with the substrate" (hereafter, referred to as
"substrate interaction group") may be included in the structural
unit (a1) or the structural unit (a2).
[0039] [Structural Unit (a1)]
[0040] The structural unit (a1) is a structural unit containing an
aromatic ring. In the case where the component (A) contains the
structural unit (a1) containing an aromatic ring, even when a block
copolymer containing a block having various characteristics is
used, the component (A) exhibits a moderate level of affinity for
the block copolymer.
[0041] The aromatic ring preferably has 6 to 18 carbon atoms.
Examples of the aromatic ring include aromatic hydrocarbon rings,
such as benzene, biphenyl, fluorene, naphthalene, anthracene and
phenanthrene; and aromatic hetero rings in which part of the carbon
atoms constituting the aforementioned aromatic rings has been
substituted with a hetero atom. Examples of the hetero atom within
the aromatic hetero rings include an oxygen atom, a sulfur atom and
a nitrogen atom.
[0042] With respect to the structural unit (a1), there is not
particular limitation to the structure of the other portion, as
long as the structural unit (a1) has an aromatic ring. Examples of
the structural unit (a1) include:
[0043] an aromatic compound (a compound containing an aromatic
ring) containing a vinyl group;
[0044] an aromatic compound containing (meth)acryloyl group;
and
[0045] a phenolic compound which is a component of a novolac
resin.
[0046] Among these, a structural unit derived from a compound in
which one hydrogen atom bonded to a carbon atom constituting an
aromatic ring which may have a substituent, has been substituted
with a vinyl group; and a structural unit derived from an acrylic
acid or ester thereof which may have the hydrogen atom bonded to
the carbon atom on the .alpha.-position substituted with a
substituent and contains an aromatic ring can be preferably used.
Here, the vinyl group may be a vinyl group in which a carbon atom
bonded to an aromatic ring may be substituted with a
substituent.
[0047] As the structural unit (a1), styrene or derivatives thereof,
vinylnaphthalene or derivatives thereof, or vinylanthracene or
derivatives thereof is particularly preferable.
[0048] Examples of "styrene and derivatives thereof" include
styrene which may have the hydrogen atom bonded to the carbon atom
on the .alpha.-position substituted with a substituent, and a
hydrogen atom bonded to the benzene ring substituted with a
substituent other than a hydroxy group (hereafter, styrene which
has the hydrogen atom bonded to the carbon atom on the
.alpha.-position substituted with a substituent is sometimes
referred to as ".alpha.-substituted styrene", and styrene which
does not have the hydrogen atom bonded to the carbon atom on the
.alpha.-position substituted with a substituent and the
aforementioned .alpha.-substituted styrene are sometimes
collectively referred to as "(.alpha.-substituted) styrene", other
similar compounds are referred to as above); hydroxystyrene which
may have the hydrogen atom bonded to the carbon atom on the
.alpha.-position substituted with a substituent, and a hydrogen
atom bonded to the benzene ring substituted with a substituent
other than a hydroxy group (hereafter, sometimes referred to as
"(.alpha.-substituted) hydroxystyrene"); a compound in which the
hydrogen atom within the hydroxy group of (.alpha.-substituted)
hydroxystyrene is substituted with an organic group; vinylbenzoic
acid which may have the hydrogen atom bonded to the carbon atom on
the .alpha.-position substituted with a substituent, and a hydrogen
atom bonded to the benzene ring substituted with a substituent
other than a hydroxy group and a carboxy group (hereafter,
sometimes referred to as "(.alpha.-substituted) vinylbenzoic
acid"); and a compound in which the hydrogen atom within the
carboxy group of (.alpha.-substituted) vinylbenzoic acid is
substituted with an organic group.
[0049] It is preferable that a hydrogen atom, an alkyl group of 1
to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon
atoms is bonded to the .alpha.-position of the .alpha.-substituted
styrene, .alpha.-substituted hydroxystyrene, or .alpha.-substituted
vinylbenzoic acid, a hydrogen atom, an alkyl group of 1 to 5 carbon
atoms or a fluorinated alkyl group of 1 to 5 carbon atoms is more
preferable, and in terms of industrial availability, a hydrogen
atom or a methyl group is the most desirable.
[0050] As the alkyl group as a substituent on the .alpha.-position,
a linear or branched alkyl group is preferable, and specific
examples include a methyl group, an ethyl group, a propyl group, an
isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl
group, a pentyl group, an isopentyl group and a neopentyl
group.
[0051] Specific examples of the halogenated alkyl group as the
substituent on the .alpha.-position include groups in which part or
all of the hydrogen atoms of the aforementioned "alkyl group as the
substituent on the .alpha.-position" are substituted with halogen
atoms. Examples of the halogen atom include a fluorine atom, a
chlorine atom, a bromine atom and an iodine atom, and a fluorine
atom is particularly desirable.
[0052] Hydroxystyrene is a compound which has 1 vinyl group and at
least 1 hydroxy group bonded to a benzene ring. The number of
hydroxy groups bonded to the benzene ring is preferably 1 to 3, and
particularly preferably 1. The bonding position of the hydroxy
group on the benzene ring is not particularly limited. When there
is 1 hydroxy group, a para-4-th position from the bonding position
of the vinyl group is preferable. When there are 2 or more hydroxy
groups, a desired combination of the bonding positions can be
used.
[0053] Vinylbenzoic acid is a compound in which one vinyl group is
bonded to the benzene ring of benzoic acid. The bonding position of
the vinyl group on the benzene ring is not particularly
limited.
[0054] The substituent other than a hydroxy group and a carboxy
group which may be bonded the benzene ring of styrene or a
derivative thereof is not particularly limited, and examples
thereof include a halogen atom, an alkyl group of 1 to 5 carbon
atoms, and a halogenated alkyl group of 1 to 5 carbon atoms.
Examples of the halogen atom include a fluorine atom, a chlorine
atom, a bromine atom and an iodine atom, and a fluorine atom is
particularly desirable.
[0055] Examples of "vinylnaphthalene and derivatives thereof"
include vinylnaphthalene which may have the hydrogen atom bonded to
the carbon atom on the .alpha.-position substituted with a
substituent, and a hydrogen atom bonded to the naphthalene ring
substituted with a substituent other than a hydroxy group
(hereafter, sometimes referred to as "(.alpha.-substituted)
vinylnaphthalene"); vinyl(hydroxynaphthalene) which may have the
hydrogen atom bonded to the carbon atom on the .alpha.-position
substituted with a substituent, and a hydrogen atom bonded to the
naphthalene ring substituted with a substituent other than a
hydroxy group (hereafter, sometimes referred to as
"(.alpha.-substituted) vinyl(hydroxynaphthalene)"); and a compound
in which the hydrogen atom within the hydroxy group of
(.alpha.-substituted) vinyl(hydroxynaphthalene) is substituted with
a substituent. In the .alpha.-substituted vinylnaphthalene or
.alpha.-substituted vinyl(hydroxynaphthalene), examples of the
substituent which substitutes the hydrogen atom bonded to the
carbon atom on the .alpha.-position is the same as those described
above for the substituent of .alpha.-substituted styrene.
[0056] Vinyl(hydroxynaphthalene) is a compound which has 1 vinyl
group and at least 1 hydroxy group bonded to a naphthalene ring.
The vinyl group may be bonded to the 1st or 2nd position of the
naphthalene ring. The number of hydroxy groups bonded to the
naphthalene ring is preferably 1 to 3, and particularly preferably
1. The bonding position of the hydroxy group on the naphthalene
ring is not particularly limited. When the vinyl group is bonded to
the 1st or 2nd position of the naphthalene ring, the hydroxy group
is preferably bonded to either one of the 5th to 8th position of
the naphthalene ring. In particular, when the number of hydroxy
group is 1, the hydroxy group is preferably bonded to either one of
the 5th to 7th position of the naphthalene ring, and more
preferably the 5th or 6th position. When there are 2 or more
hydroxy groups, a desired combination of the bonding positions can
be used.
[0057] As the substituent which may be bonded to the naphthalene
ring of vinylnaphthalene and derivatives thereof, the same
substituents as those described above for the substituent which may
be bonded to the benzene ring of the (.alpha.-substituted) styrene
can be mentioned.
[0058] As the "vinylanthracene or derivatives thereof", a
vinylanthracene in which the hydrogen atom bonded to the carbon
atom on the .alpha.-position may be substituted with a substituent,
and a hydrogen atom bonded to the anthracene ring may be
substituted with a substituent other than a hydroxy group, can be
mentioned. The substituent is the same as those described above for
the substituent of .alpha.-substituted styrene.
[0059] An "acrylate ester" refers to a compound in which the
terminal hydrogen atom of the carboxy group of acrylic acid
(CH.sub.2.dbd.CH--COOH) has been substituted with an organic
group.
[0060] In the .alpha.-substituted acrylic acid which may have the
hydrogen atom bonded to the carbon atom on the .alpha.-position
substituted with a substituent (hereafter, frequently referred to
as "(.alpha.-substituted) acrylic acid") or ester thereof, examples
of the substituent which substitutes the hydrogen atom bonded to
the carbon atom on the .alpha.-position is the same as those
described above for the substituent of .alpha.-vinylnaphthalene,
.alpha.-substituted vinyl(hydroxynaphthalene), and
.alpha.-substituted styrene. With respect to the "structural unit
derived from an acrylate ester", the ".alpha.-position (the carbon
atom on the .alpha.-position)" refers to the carbon atom having the
carbonyl group bonded thereto, unless specified otherwise.
[0061] The organic group which the (.alpha.-substituted) acrylate
ester thereof has is not particularly limited, and the same groups
as those described later as an organic group for X.sup.c and
X.sup.d can be mentioned.
[0062] As the structural unit (a1), structural units represented by
general formulas (a1-1) to (a1-4) shown below are particularly
preferable.
##STR00001##
[0063] In the formulae, R represents a hydrogen atom, an alkyl
group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5
carbon atoms; X.sup.c and X.sup.d each independently represents a
hydrogen atom, a hydroxy group, a cyano group or an organic group;
R.sup.c and R.sup.d each independently represents a halogen atom,
--COOX.sup.e (X.sup.e represents a hydrogen atom or an organic
group), an alkyl group of 1 to 5 carbon atoms or a halogenated
alkyl group of 1 to 5 carbon atoms; px represents an integer of 0
to 3, qx represents an integer of 0 to 5, and px+qx=1 to 5,
provided that, when qx is an integer of 2 or more, the plurality of
R.sup.c groups may be the same or different from each other; x
represents an integer of 0 to 3, y represents an integer of 0 to 3,
y' represents an integer of 0 to 2, z represents an integer of 0 to
4, and in the formula (a1-2), x+y+z=1 to 7, and in the formula
(a1-3), x+y+y'+z=1 to 7, provided that, when y+z or y+y'+z is an
integer of 2 or more, the plurality of R.sup.d groups may be the
same or different from each other; and X.sup.Ar represents a
monovalent organic group containing an aromatic ring.
[0064] In general formulas, the alkyl group and the halogenated
alkyl group for R are respectively the same as defined for the
alkyl group and the halogenated alkyl group for the substituent
which may be bonded to the carbon atom on the .alpha.-position of
the aforementioned .alpha.-substituted styrene. R is preferably a
hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a
fluorinated alkyl group of 1 to 5 carbon atoms, and most preferably
a hydrogen atom or a methyl group.
[0065] The organic group for X.sup.c and X.sup.d is not
particularly limited, as long as they contains a carbon atom. The
organic group may include atoms other than carbon atoms (e.g., a
hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a
halogen atom (such as a fluorine atom and a chlorine atom), silicon
atom and the like).
[0066] As the organic group for X.sup.c and X.sup.d, a hydrocarbon
group which may have a substituent is preferable, and an alkyl
group which may have a substituent is more preferable.
[0067] Examples of the alkyl group which may have substituent
include an unsubstituted alkyl group, and a substituted alkyl group
in which part or all of the hydrogen atoms within an unsubstituted
alkyl group has been substituted with a substituent.
[0068] The unsubstituted alkyl group may be any of linear, branched
or cyclic. In terms of superiority in resolution, an alkyl group of
1 to 10 carbon atoms is preferable, and an alkyl group of 1 to 5
carbon atoms is more preferable. Specific examples include a methyl
group, an ethyl group, an n-propyl group, an isopropyl group, an
n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl
group, a hexyl group, a cyclohexyl group, a nonyl group and a decyl
group.
[0069] Examples of the substituent of the substituted alkyl group
include an alkoxy group, a halogen atom, a halogenated alkyl group,
a hydroxyl group, an oxo group (.dbd.O) and a cyano group.
[0070] The alkoxy group as the substituent is preferably an alkoxy
group having 1 to 5 carbon atoms, more preferably a methoxy group,
an ethoxy group, an n-propoxy group, an iso-propoxy group, an
n-butoxy group or a tert-butoxy group, and most preferably a
methoxy group or an ethoxy group.
[0071] Examples of the halogen atom for the substituent include a
fluorine atom, a chlorine atom, a bromine atom and an iodine atom,
and a fluorine atom is preferable.
[0072] Examples of the halogenated alkyl group for the substituent
include groups in which part or all of the hydrogen atoms within
the aforementioned alkyl groups has been substituted with the
aforementioned halogen atoms.
[0073] Further, part of the carbon atoms constituting the
unsubstituted or substituted alkyl group may be substituted with a
substituent containing a hetero atom. The substituent containing a
hetero atom is preferably --O--, --C(.dbd.O)--O--, --S--,
--S(.dbd.O).sub.2--, --S(.dbd.O).sub.2--O-- or --Si--.
[0074] In the formula, the halogen atom for R.sup.c and R.sup.d is
preferably a fluorine atom, a chlorine atom, a bromine atom and an
iodine atom, and a fluorine atom is preferable.
[0075] With respect to --COOX.sup.e in R.sup.c and R.sup.d, X.sup.e
represents a hydrogen atom or an organic group, and the organic
group is the same as the organic group described above for and
X.sup.d.
[0076] The alkyl group of 1 to 5 carbon atoms or halogenated alkyl
group of 1 to 5 carbon atoms for R.sup.c and R.sup.d are the same
as the alkyl group of 1 to 5 carbon atoms or halogenated alkyl
group of 1 to 5 carbon atoms for R.
[0077] X.sup.Ar represents a monovalent organic group containing an
aromatic ring, and examples thereof include a group in which one or
more hydrogen atom has been removed from the aforementioned
aromatic ring, and a group in which one hydrogen atom has been
removed from benzene, naphthalene or anthracene is preferable.
[0078] As the structural unit (a1) contained in the component (A),
1 type of structural unit may be used, or 2 or more types may be
used.
[0079] In the component (A), the amount of the structural unit (a1)
based on the combined total of all structural units constituting
the component (A) is preferably 10 to 95 mol %, more preferably 20
to 90 mol %, still more preferably 30 to 90 mol %, and most
preferably 50 to 85 mol %.
[0080] When the amount of the structural unit (a1) is at least as
large as the lower limit of the above-mentioned range, the layer
containing the block copolymer and constituting an upper layer is
satisfactorily subjected to phase separation. On the other hand,
when the amount of the structural unit (a1) is no more than the
upper limit of the above-mentioned range, a good balance can be
reliably achieved with the structural unit (a2).
[0081] [Structural unit (a2)]
[0082] The structural unit (a2) is a structural unit having no
aromatic ring. When the component (A) contains both the structural
unit (a1) and the structural unit (a2), the component (A) exhibits
affinity for any of the structural units constituting the block
copolymer.
[0083] There is no particularly limitation on the structural unit
(a2), as long as the structural unit (a2) does not have the
aromatic ring described above in relation to the structural unit
(a1) in the structure thereof. Examples thereof includes: [0084] A
structural unit derived from an acrylic acid or ester thereof which
may have the hydrogen atom bonded to the carbon atom on the
.alpha.-position substituted with a substituent and has no aromatic
ring; [0085] A structural unit derived from an acrylamide or
derivatives thereof which may have the hydrogen atom bonded to the
carbon atom on the .alpha.-position substituted with a substituent
and has no aromatic ring; [0086] A structural unit which is derived
from a cycloolefine or derivatives thereof and has no aromatic
ring; and [0087] A structural unit which is derived from a
vinylsulfonate ester or derivatives thereof and has no aromatic
ring.
[0088] Among these, a structural unit derived from an acrylic acid
or an ester thereof which may have the hydrogen atom bonded to the
carbon atom on the .alpha.-position substituted with a substituent,
or a structural unit derived from an acrylamide or a derivative
thereof in which the hydrogen atom bonded to the carbon atom on the
.alpha.-position may be substituted with a substituent is
preferable.
[0089] Examples of "acrylamide and derivatives thereof" include
acrylamide in which the hydrogen atom bonded to the carbon atom on
the .alpha.-position may be substituted with a substituent
(hereafter, sometimes referred to as (.alpha.-substituted)
acrylamide), and a compound in which either or both terminal
hydrogen atoms on the amino group of .alpha.-substituted)
acrylamide is substituted with a substituent.
[0090] As the substituent to be bonded to the carbon atom on the
.alpha.-position of acrylamide and derivatives thereof, the same
substituents as those described above for the substituent to be
bonded to the carbon atom on the .alpha.-position of an
.alpha.-substituted styrene can be mentioned.
[0091] As the substituent which substitutes either or both terminal
hydrogen atoms on the amino group of (.alpha.-substituted)
acrylamide, an organic group is preferable. The organic group is
not particularly limited, and examples thereof include the same
organic groups as those described above for (.alpha.-substituted)
acrylate ester.
[0092] Examples of the compound in which either or both terminal
hydrogen atoms on the amino group of (.alpha.-substituted)
acrylamide is substituted with a substituent include a compound in
which --C(.dbd.O)--O-- bonded to the carbon atom on the
.alpha.-position of the aforementioned (.alpha.-substituted)
acrylate ester is replaced by --C(.dbd.O)--N(R.sup.b)-- (in the
formula, R.sup.b represents a hydrogen atom or an alkyl group of 1
to 5 carbon atoms).
[0093] In the formula, the alkyl group for R.sup.b is preferably
linear or branched.
[0094] As the structural unit (a2), structural units represented by
general formulas (a2-1) and (a2-2) shown below are particularly
preferable.
##STR00002##
[0095] In the formulas, R is the same as defined above; X.sup.a and
X.sup.b each independently represents a hydrogen atom or an organic
group which does not contain an aromatic ring; and Rb represents a
hydrogen atom or an alkyl group of 1 to 5 carbon atoms.
[0096] In the formulas, X.sup.a and X.sup.b each independently
represents a hydrogen atom or an organic group. The organic group
is not particularly limited, as long as they contains a carbon atom
and does not contain an aromatic ring. The organic group may
include atoms other than carbon atoms (e.g., a hydrogen atom, an
oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom (such
as a fluorine atom and a chlorine atom), silicon atom and the
like). The organic group for X.sup.a and X.sup.b is the same
organic group as described above for X.sup.c and X.sup.d.
[0097] In the formulas, examples of the alkyl group of 1 to 5
carbon atoms represented by R.sup.b include the same alkyl group of
1 to 5 carbon atoms as those described above for R.
[0098] As the structural unit (a2) contained in the component (A),
1 type of structural unit may be used, or 2 or more types may be
used.
[0099] In the component (A), the amount of the structural unit (a2)
based on the combined total of all structural units constituting
the component (A) is preferably 5 to 90 mol %, more preferably 10
to 80 mol %, still more preferably 10 to 70 mol %, and most
preferably 15 to 50 mol %.
[0100] When the amount of the structural unit (a2) is at least as
large as the lower limit of the above-mentioned range, the layer
containing the block copolymer constituting an upper layer is
satisfactorily subjected to phase separation. On the other hand,
when the amount of the structural unit (a2) is no more than the
upper limit of the above-mentioned range, a good balance can be
reliably achieved with the structural unit (a1).
[0101] {Ether-Containing Cyclic Group}
[0102] The component (A) of the present invention does not include
a 3 to 7-membered, ether-containing cyclic group. By virtue of the
undercoat agent of the present invention not containing
ether-containing cyclic group, polymerization reaction caused by
the cleavage of the ether-containing cyclic group during
heating-drying process after applying the undercoat agent on a
substrate does not occur. Therefore, for example, by applying the
undercoat agent on a substrate, followed by drying and washing
(rinse) with an appropriate solvent, the thickness of the layer
composed of the undercoat agent can be reduced.
[0103] Here, the "ether-containing cyclic group" refers to a cyclic
group including a structure in which a carbon atom within the
cyclic hydrocarbon group has been replaced with an oxygen atom
(cyclic ether). Provided that, the cyclic group which includes a
cyclic ether structure and falls under the definition of
"lactone-containing cyclic group" described later is not regarded
as the "ether-containing cyclic group".
[0104] The component (A) of the present invention includes the
structural units (a1) and (a2), and therefore, these structural
units do not include a 3 to 7-membered, ether-containing cyclic
group. For example, when the structural units (a1) and (a2) are
structural units represented by the formula (a1-1) to (a1-4), and
(a2-1) to (a2-2), the organic groups for X.sup.a to X.sup.d,
R.sup.b to R.sup.d, and X.sup.Ar do not include an ether-containing
cyclic group.
[0105] {Substrate Interaction Group}
[0106] The component (A) of the present invention includes a
substrate interaction group. By including the substrate interaction
group within the component (A), the undercoat agent containing the
component (A) interacts with the substrate, thereby forming a
strong film (a layer composed of the undercoat agent) on the
substrate, and as a result, the layer containing the block
copolymer can undergo favorable phase separation on top of the
layer composed of the undercoat agent. By including the substrate
interaction group within the component (A), an undercoat agent
containing a component (A) interacts with the surface of the
substrate, and then a monomolecular film is formed by
self-assembly. As a result, a layer composed of an undercoat agent
becomes a very thin film, and does not become an impediments in a
later step.
[0107] In the present invention, the "group that can interact with
the substrate", that is, the "substrate interaction group"
describes a group that can interact chemically or physically with
the substrate, and this group can be selected appropriately in
accordance with the type of substrate being used. Examples of the
types of interaction between the substrate and the substrate
interaction group include covalent bonding interactions, ionic
bonding interactions, hydrogen bonding interactions, electrostatic
interactions, hydrophobic interactions, and van der Waals force
interactions.
[0108] Specific examples of such substrate interaction groups
include a carboxy group, a cyano group, an amino group, a
trialkoxysilyl group, a dialkoxysilyl group, and a mono-alkoxysilyl
group and the like. Among these, a carboxy group, a cyano group, an
amino group or a trialkoxysilyl group is preferable. As the alkoxy
group in the trialkoxysilyl group, a methoxy group or an ethoxy
group is preferable, and a methoxy group is particularly
preferable.
[0109] In the present invention, a substrate interaction group is
preferably a lactone-containing cyclic group.
[0110] The term "lactone-containing cyclic group" refers to a
cyclic group including a ring containing a --O--C(.dbd.O)--
structure (lactone ring). The term "lactone ring" refers to a
single ring containing a --O--C(.dbd.O)-- structure, and this ring
is counted as the first ring. A lactone-containing cyclic group in
which the only ring structure is the lactone ring is referred to as
a monocyclic group, and groups containing other ring structures are
described as polycyclic groups regardless of the structure of the
other rings. The lactone-containing cyclic group may be either a
monocyclic group or a polycyclic group.
[0111] The lactone-containing cyclic group for R.sup.1 is not
particularly limited, and an arbitrary structural unit may be used.
Specific examples include structural units represented by general
formulas (lc-1) to (lc-r-7) shown below. Hereafter, "*" represents
a valence bond.
##STR00003##
[0112] In the formulas, each Ra'.sup.21 independently represents a
hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a
halogenated alkyl group, a hydroxy group, --COOR'',
--OC(.dbd.O)R'', a hydroxyalkyl group or a cyano group; R''
represents a hydrogen atom or an alkyl group; A'' represents an
oxygen atom, a sulfur atom or an alkylene group of 1 to 5 carbon
atoms which may contain an oxygen atom or a sulfur atom; n'
represents an integer of 0 to 2; and m' represents 0 or 1.
[0113] In general formulas (lc-1) to (lc-r-7), A'' represents an
oxygen atom, a sulfur atom or an alkylene group of 1 to 5 carbon
atoms which may contain an oxygen atom (--O--) or a sulfur atom
(--S--). As the alkylene group of 1 to 5 carbon atoms for A'', a
linear or branched alkylene group is preferable, and examples
thereof include a methylene group, an ethylene group, an
n-propylene group and an isopropylene group. Examples of alkylene
groups that contain an oxygen atom or a sulfur atom include the
aforementioned alkylene groups in which --O-- or --S-- is bonded to
the terminal of the alkylene group or interposed within the alkyl
group. Specific examples of such alkylene groups include
--O--CH.sub.2--, --CH.sub.2--O--CH.sub.2--, --S--CH.sub.2-- and
--CH.sub.2--S--CH.sub.2--. As A'', an alkylene group of 1 to 5
carbon atoms or --O-- is preferable, more preferably an alkylene
group of 1 to 5 carbon atoms, and most preferably a methylene
group. Each Ra'.sup.21 independently represents an alkyl group, an
alkoxy group, a halogen atom, a halogenated alkyl group, --COOR'',
--OC(.dbd.O)R'', a hydroxyalkyl group or a cyano group.
[0114] The alkyl group for Ra'.sup.21 is preferably an alkyl group
of 1 to 5 carbon atoms.
[0115] The alkoxy group for Ra'.sup.21 is preferably an alkoxy
group of 1 to 6 carbon atoms.
[0116] Further, the alkoxy group is preferably a linear or branched
alkoxy group. Specific examples of the alkoxy groups include the
aforementioned alkyl groups for Ra'.sup.21 having an oxygen atom
(--O--) bonded thereto.
[0117] As examples of the halogen atom for Ra'.sup.21, a fluorine
atom, chlorine atom, bromine atom and iodine atom can be given.
Among these, a fluorine atom is preferable.
[0118] Examples of the halogenated alkyl group for Ra'.sup.21
include groups in which part or all of the hydrogen atoms within
the aforementioned alkyl groups for Ra'.sup.21 has been substituted
with the aforementioned halogen atoms. As the halogenated alkyl
group, a fluorinated alkyl group is preferable, and a
perfluoroalkyl group is particularly desirable.
[0119] With respect to --COOR'' and --OC(.dbd.O)R'' for Ra'.sup.21,
R'' represents a hydrogen atom or an alkyl group.
[0120] In the present invention, among these, the group represented
by general formula (lc-1) or (lc-r-2) is preferable.
[0121] Specific examples of the group represented by the
aforementioned general formulas (lc-1) to (lc-r-7) are shown
below.
##STR00004## ##STR00005## ##STR00006## ##STR00007## ##STR00008##
##STR00009##
[0122] In the present invention, among the examples shown above, as
the lactone-containing cyclic group, groups represented by general
formulas (r-lc-1-1) to (r-lc-1-7), and (r-lc-2-1) to (r-lc-2-13) is
preferable, and groups represented by general formulas (r-lc-1-1)
to (r-lc-1-7) are particularly preferable.
[0123] In the present invention, as the substrate interaction group
may be an organic group containing a fluorine atom. As the organic
group containing a fluorine atom is preferably a hydrocarbon group
containing a fluorine atom.
[0124] The hydrocarbon group containing a fluorine atom may be
linear, branched or cyclic, and preferably has 1 to 20 carbon
atoms, more preferably 1 to 15 carbon atoms, and most preferably 1
to 10 carbon atoms.
[0125] It is preferable that the hydrocarbon group having a
fluorine atom has 25% or more of the hydrogen atoms within the
hydrocarbon group fluorinated, more preferably 50% or more, and
most preferably 60% or more, as the hydrophobicity of the resist
film during immersion exposure is enhanced.
[0126] Among these, in the present invention, a fluorinated
hydrocarbon group of 1 to 5 carbon atoms is particularly
preferable, and a methyl group, --CH.sub.2--CF.sub.3,
--CH.sub.2--CF.sub.2--CF.sub.3, --CH(CF.sub.3).sub.2,
--CH.sub.2--CH.sub.2--CF.sub.3, and
--CH.sub.2--CH.sub.2--CF.sub.2--CF.sub.2--CF.sub.2--CF.sub.3 are
most preferable.
[0127] As described above, the substrate interaction group may be
included in the structural unit (a1) or the structural unit (a2).
Among these, the substrate interaction group is preferably included
in the structural unit (a2). Hereafter, the structural unit (a2)
containing a substrate interaction group is referred to as a
structural unit (a21).
[0128] As the structural unit (a21), those represented by formulas
(a21-1) and (a21-2) shown below are preferable.
##STR00010##
[0129] In the formulas, R and Rb are the same as defined above;
Y.sup.01 represents a single bond or a divalent linking group which
does not contain an aromatic ring; X.sup.01 represents a hydrogen
atom, a carboxyl group, a cyano group, an amino group, a
trialkoxysilyl group, a lactone-containing cyclic group or an
organic group containing a fluorine atom, provided that, when
X.sup.01 is a hydrogen atom, Y.sup.01 represents a single bond, and
when X.sup.01 is a carboxy group, a cyano group, an amino group or
a trialkoxysilyl group, Y.sup.01 represents a divalent linking
group which does not have an aromatic ring; Y.sup.02 represents a
divalent linking group which does not have an aromatic ring; and
X.sup.02 represents a carboxy group, a cyano group, an amino group
or a trialkoxysilyl group.
[0130] In the formulas, Y.sup.01 may be a single bond or a divalent
linking group which does not contain an aromatic ring. The divalent
linking group for Y.sup.01 is not particularly limited, as long as
it does not contain an aromatic ring, and preferable examples
thereof include: a divalent hydrocarbon group which does not
contain an aromatic ring and may have a substituent; and a divalent
linking group which does not contain an aromatic ring and contains
a hetero atom.
[0131] (Divalent Hydrocarbon Group which May have a
Substituent)
[0132] The hydrocarbon group as a divalent linking group which does
not have an aromatic ring is preferably an aliphatic hydrocarbon
group.
[0133] An "aliphatic hydrocarbon group" refers to a hydrocarbon
group that has no aromaticity. The aliphatic hydrocarbon group may
be saturated or unsaturated. In general, the aliphatic hydrocarbon
group is preferably saturated.
[0134] As specific examples of the aliphatic hydrocarbon group, a
linear or branched aliphatic hydrocarbon group, and an aliphatic
hydrocarbon group containing a ring in the structure thereof can be
given.
[0135] The linear or branched aliphatic hydrocarbon group
preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and
still more preferably 1 to 5.
[0136] As the linear aliphatic hydrocarbon group, a linear alkylene
group is preferable, and specific examples include a methylene
group [--CH.sub.2--], an ethylene group [--(CH.sub.2).sub.2--], a
trimethylene group [--(CH.sub.2).sub.3--], a tetramethylene group
[--(CH.sub.2).sub.4--] and a pentamethylene group
[--(CH.sub.2).sub.5--].
[0137] As the branched aliphatic hydrocarbon group, a branched
alkylene group is preferable, and specific examples include
alkylalkylene groups, e.g., alkylmethylene groups such as
--CH(CH.sub.3)--, --CH(CH.sub.2CH.sub.3)--, --C(CH.sub.3).sub.2--,
--C(CH.sub.3)(CH.sub.2CH.sub.3)--,
--C(CH.sub.3)(CH.sub.2CH.sub.2CH.sub.3)--, and
--C(CH.sub.2CH.sub.3).sub.2--; alkylethylene groups such as
--CH(CH.sub.3)CH.sub.2--, --CH(CH.sub.3)CH(CH.sub.3)--,
--C(CH.sub.3).sub.2CH.sub.2--, --CH(CH.sub.2CH.sub.3)CH.sub.2--,
and --C(CH.sub.2CH.sub.3).sub.2--CH.sub.2--; alkyltrimethylene
groups such as --CH(CH.sub.3)CH.sub.2CH.sub.2--, and
--CH.sub.2CH(CH.sub.3)CH.sub.2--; and alkyltetramethylene groups
such as --CH(CH.sub.3)CH.sub.2CH.sub.2CH.sub.2--, and
--CH.sub.2CH(CH.sub.3)CH.sub.2CH.sub.2--. As the alkyl group within
the alkylalkylene group, a linear alkyl group of 1 to 5 carbon
atoms is preferable.
[0138] The linear or branched aliphatic hydrocarbon group may or
may not have a substituent (a group or an atom other than a
hydrogen atom) for substituting a hydrogen atom. Examples of the
substituent include a fluorine atom, a fluorinated alkyl group of 1
to 5 carbon atoms, and an oxo group (.dbd.O).
[0139] As examples of the hydrocarbon group containing a ring in
the structure thereof, a cyclic aliphatic hydrocarbon group which
may have a substituent containing a hetero atom (a group in which
two hydrogen atoms have been removed from an aliphatic hydrocarbon
ring), a group in which the cyclic aliphatic hydrocarbon group is
bonded to the terminal of a linear or branched aliphatic
hydrocarbon group, and a group in which the cyclic aliphatic group
is interposed within a linear or branched aliphatic hydrocarbon
group, can be given. As the linear or branched aliphatic
hydrocarbon group, the same groups as those described above can be
used.
[0140] The cyclic aliphatic hydrocarbon group preferably has 3 to
20 carbon atoms, and more preferably 3 to 12 carbon atoms.
[0141] The cyclic aliphatic hydrocarbon group may be either a
polycyclic group or a monocyclic group. As the monocyclic aliphatic
hydrocarbon group, a group in which 2 hydrogen atoms have been
removed from a monocycloalkane is preferable. The monocycloalkane
preferably has 3 to 6 carbon atoms, and specific examples thereof
include cyclopentane and cyclohexane. As the polycyclic aliphatic
hydrocarbon group, a group in which two hydrogen atoms have been
removed from a polycycloalkane is preferable, and the polycyclic
group preferably has 7 to 12 carbon atoms. Examples of the
polycycloalkane include adamantane, norbornane, isobornane,
tricyclodecane and tetracyclododecane.
[0142] The cyclic aliphatic hydrocarbon group may or may not have a
substituent (a group or an atom other than a hydrogen atom) for
substituting a hydrogen atom. Examples of substituents include an
alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl
group, a hydroxyl group and an oxo group (.dbd.O).
[0143] The alkyl group as the substituent is preferably an alkyl
group of 1 to 5 carbon atoms, and a methyl group, an ethyl group, a
propyl group, an n-butyl group or a tert-butyl group is most
desirable.
[0144] The alkoxy group as the substituent is preferably an alkoxy
group having 1 to 5 carbon atoms, more preferably a methoxy group,
an ethoxy group, an n-propoxy group, an iso-propoxy group, an
n-butoxy group or a tert-butoxy group, and most preferably a
methoxy group or an ethoxy group.
[0145] Examples of the halogen atom for the substituent include a
fluorine atom, a chlorine atom, a bromine atom and an iodine atom,
and a fluorine atom is preferable.
[0146] Examples of the halogenated alkyl group for the substituent
include groups in which part or all of the hydrogen atoms within
the aforementioned alkyl groups has been substituted with the
aforementioned halogen atoms.
[0147] In the cyclic aliphatic hydrocarbon group, part of the
carbon atoms constituting the ring structure thereof may be
substituted with a substituent containing a hetero atom. The
substituent containing a hetero atom is preferably --O--,
--C(.dbd.O)--O--, --S--, --S(.dbd.O).sub.2--, or
--S(.dbd.O).sub.2--O--.
[0148] (Divalent Linking Group Containing a Hetero Atom)
[0149] With respect to a "divalent linking group containing a
hetero atom" for Y.sup.0, a hetero atom is an atom other than
carbon and hydrogen, and examples thereof include an oxygen atom, a
nitrogen atom, a sulfur atom and a halogen atom.
[0150] Examples of the divalent linking group containing a hetero
atom include --O--, --C(.dbd.O)--O--, --C(.dbd.O)--,
--O--C(.dbd.O)--O--, --C(.dbd.O)--NH--, --NH-- (H may be
substituted with a substituent such as an alkyl group or an acyl
group), --S--, --S(.dbd.O).sub.2--, --S(.dbd.O).sub.2--O--,
--NH--C(.dbd.O)--, .dbd.N--, and a group represented by general
formula --Y.sup.21--O--Y.sup.22--,
--[Y.sup.21--C(.dbd.)--O].sub.m'--Y.sup.22--,
--C(.dbd.O)--O--Y.sup.22-- or --Y.sup.21--O--C(.dbd.O)--Y.sup.22--
[in the formulae, each of Y.sup.21 and Y.sup.22 independently
represents a divalent hydrocarbon group which may have a
substituent; O represents an oxygen atom; and m' represents an
integer of 0 to 3].
[0151] When Y.sup.0 represents --NH--, H may be substituted with a
substituent such as an alkyl group, an acyl group or the like. The
substituent (an alkyl group, an aryl group or the like) preferably
has 1 to 10 carbon atoms, more preferably 1 to 8, and most
preferably 1 to 5.
[0152] Each of Y.sup.21 and Y.sup.22 independently represents a
divalent hydrocarbon group which may have a substituent. As the
divalent hydrocarbon group, the same groups as those described
above for the "divalent hydrocarbon group which may have a
substituent" for Y.sup.0 can be mentioned.
[0153] As Y.sup.21, a linear aliphatic hydrocarbon group is
preferable, more preferably a linear alkylene group, still more
preferably a linear alkylene group of 1 to 5 carbon atoms, and a
methylene group or an ethylene group is particularly desirable.
[0154] As Y.sup.22, a linear or branched aliphatic hydrocarbon
group is preferable, and a methylene group, an ethylene group or an
alkylmethylene group is more preferable. The alkyl group within the
alkylmethylene group is preferably a linear alkyl group of 1 to 5
carbon atoms, more preferably a linear alkyl group of 1 to 3 carbon
atoms, and most preferably a methyl group.
[0155] In the group represented by the formula
--[Y.sup.21--C(.dbd.O)--O].sub.m'--Y.sup.22--, m' represents an
integer of 0 to 3, preferably an integer of 0 to 2, more preferably
0 or 1, and particularly preferably 1. Namely, it is particularly
desirable that the group represented by the formula
--[Y.sup.21--C(.dbd.O)--O].sub.m'--Y.sup.22-- is a group
represented by the formula --Y.sup.21--C(.dbd.O)--O--Y.sup.22--.
Among these, a group represented by the formula
--(CH.sub.2).sub.a'--C(.dbd.O)--O--(CH.sub.2).sub.b' is preferable.
In the formula, a' is an integer of 1 to 10, preferably an integer
of 1 to 8, more preferably an integer of 1 to 5, still more
preferably 1 or 2, and most preferably 1. b' is an integer of 1 to
10, preferably an integer of 1 to 8, more preferably an integer of
1 to 5, still more preferably 1 or 2, and most preferably 1.
[0156] As the divalent linking group containing a hetero atom, a
linear group containing an oxygen atom as the hetero atom e.g., a
group containing an ether bond or an ester bond is preferable, and
a group represented by the aforementioned formula
--Y.sup.21--O--Y.sup.22--,
--[Y.sup.21--C(.dbd.O)--O].sub.m'--Y.sup.22-- or
--Y.sup.21--O--C(.dbd.O)--Y.sup.22-- is more preferable.
[0157] Among the aforementioned examples, as the divalent linking
group for Y.sup.01, a linear or branched alkylene group, a divalent
alicyclic hydrocarbon group or a divalent linking group containing
a hetero atom is particularly desirable. Among these, a linear or
branched alkylene group or a divalent linking group containing an
ester bond (--C(.dbd.O)--O--) is more preferable.
[0158] In the formulas, X.sup.01 represents a hydrogen atom, a
carboxy group, a cyano group, an amino group or a trialkoxysilyl
group, and an alkoxy group in the trialkoxysilyl group is the same
as described above, and as the trialkoxysilyl group, a
trimethoxysilyl group is preferable.
[0159] In the formulas, Y.sup.02 represents a divalent linking
group which does not contain an aromatic ring, and is the same as
the divalent linking group which does not have an aromatic ring
described above for Y.sup.01.
[0160] The trialkoxysilyl group for X.sup.02 is the same as the
trialkoxysiliy group for X.sup.01.
[0161] Specific examples of the structural unit (a21) are shown
below. In the formulas, R is the same as defined above.
##STR00011##
[0162] As the structural unit (a21), one type of structural unit
may be used, or two or more types may be used in combination.
[0163] In the structural unit (a2), the amount of the structural
unit (a21) is preferably 5 to 100 mol %, and more preferably 10 to
100 mol %. Namely, the structural unit (a2) may consist of the
structural unit (a21).
[0164] The weight average molecular weight (Mw) (the polystyrene
equivalent value determined by gel permeation chromatography) of
the component (A) is not particularly limited, but is preferably
1,000 to 200,000, more preferably 1,500 to 200,000, and most
preferably 2,000 to 150,000. When the weight average molecular
weight is no more than the upper limit of the above-mentioned
range, the undercoat agent containing the component (A) exhibits a
satisfactory solubility in an organic solvent described later,
thereby achieving an excellent applicability on the substrate. On
the other hand, when the weight average molecular weight is at
least as large as the lower limit of the above-mentioned range, the
composition exhibits an excellent production stability and an
excellent applicability on the substrate.
[0165] Further, the dispersity (Mw/Mn) is not particularly limited,
but is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most
preferably 1.0 to 2.5. Here, Mn is the number average molecular
weight.
[0166] The component (A) can be obtained, for example, by a
conventional radical polymerization or the like of the monomers
corresponding with each of the structural units, using a radical
polymerization initiator such as azobisisobutyronitrile (AIBN).
[0167] Furthermore, in the component (A), by using a chain transfer
agent such as
HS--CH.sub.2--CH.sub.2--CH.sub.2--C(CF.sub.3).sub.2--OH, a
--C(CF.sub.3).sub.2--OH group can be introduced at the terminals of
the component (A).
[0168] As the monomers for deriving the corresponding structural
units, commercially available monomers may be used, or the monomers
may be synthesized by a conventional method.
[0169] In the undercoat agent of the present invention, as the
component (A), one type may be used, or two or more types may be
used in combination.
[0170] In the undercoat agent of the present invention, the amount
of the component (A) can be appropriately adjusted depending on the
desired thickness of the layer composed of the undercoat agent, and
the like.
[0171] <Optional Components>
[0172] [Acidic Compound Component; Component (G)]
[0173] The undercoat agent of the present invention may further
include an acidic compound component (G) (hereafter, frequently
referred to as "component (G)"), in addition to the component (A).
When the undercoat agent contains the component (G), an interaction
is likely to occur between a substrate interaction group within the
component (A) and a substrate, thereby improving the adhesion of
the layer composed of the undercoat agent to the substrate. By
virtue of the interaction being likely to occur, after applying the
undercoat agent on the substrate, it becomes possible to conduct
heating for the purpose of promoting interaction at a low
temperature, or the heating time can be shortened, thereby enabling
simplification of work processes and shortening of work process
time.
[0174] In the present invention, an acidic compound refers to a
compound which exhibits acidity itself, i.e., a compound that acts
as a proton donor.
[0175] In the present invention, as the component (G),
[0176] an acidic salt having an acid strength sufficient for
exerting the aforementioned effects (hereafter, referred to as
"component (G1)") or
[0177] an acid other than acidic salts (acids which do not form a
salt, acids which are not ionic; hereafter, referred to as
"component (G2)") can be used.
[0178] [Component (G1)]
[0179] Examples of the component (G1) include an ionic compound
(salt compound) having a nitrogen-containing cation and a
counteranion. The component (G1) itself exhibits acidity even in
the form of a salt, and acts as a proton donor.
[0180] Hereafter, the cation moiety and the anion moiety of the
component (G1) will be described.
[0181] (Cation Moiety of Component (G1))
[0182] The cation moiety of the component (G1) is not particularly
limited as long as it contains a nitrogen atom. As a preferable
example, a cation represented by general formula (Glc-1) shown
below can be mentioned.
##STR00012##
[0183] In the formula, R.sup.101d, R.sup.101e, R.sup.101f and
R.sup.101g each independently represents a hydrogen atom, a linear,
branched or cyclic alkyl group, an alkenyl group, an oxoalkyl group
or an oxoalkenyl group of 1 to 12 carbon atoms, an aryl group or an
arylalkyl group of 6 to 20 carbon atoms, an aralkyl group of 7 to
12 carbon atoms or an aryloxoalkyl group, and part or all of the
hydrogen atoms of these groups may be substituted with a halogen
atom, an alkoxy group or a sulfur atom. R.sup.101d and R.sup.101e,
or R.sup.101d, R.sup.101e and R.sup.101f may be mutually bonded
with the nitrogen atom to form a ring, provided that, when a ring
is formed, each of R.sup.101d and R.sup.101e, or each of
R.sup.101d, R.sup.101e and R.sup.101f independently represents an
alkylene group of 3 to 10 carbon atoms, or forms a hetero aromatic
ring containing the nitrogen atom in the ring thereof.
[0184] In formula (Glc-1), R.sup.101d, R.sup.101f, R.sup.101e and
R.sup.101g independently represents a hydrogen atom, a linear,
branched or cyclic alkyl group, an alkenyl group, an oxoalkyl group
or an oxoalkenyl group of 1 to 12 carbon atoms, an aryl group or an
arylalkyl group of 6 to 20 carbon atoms, an aralkyl group of 7 to
12 carbon atoms or an aryloxoalkyl group.
[0185] The alkyl group for R.sup.101d to R.sup.101g preferably has
1 to 10 carbon atoms, and a methyl group, an ethyl group, a propyl
group or a butyl group is particularly desirable.
[0186] The alkenyl group for R.sup.101d to R.sup.101g preferably
has 2 to 10 carbon atoms, more preferably 2 to 5, and still more
preferably 2 to 4. Specific examples thereof include a vinyl group,
a propenyl group (an allyl group), a butynyl group, a
1-methylpropenyl group and a 2-methylpropenyl group.
[0187] The oxoalkyl group for R.sup.101d to R.sup.101g preferably
has 2 to 10 carbon atoms, and examples thereof include a 2-oxoethyl
group, a 2-oxopropyl group, a 2-oxocyclopentyl group and a
2-oxocyclohexyl group.
[0188] Examples of the oxoalkenyl group for R.sup.101d to
R.sup.101g include an oxo-4-cyclohexenyl group and a
2-oxo-4-propenyl group.
[0189] The aryl group for R.sup.101d to R.sup.101g preferably has 5
to 30 carbon atoms, more preferably 5 to 20, still more preferably
6 to 15, and most preferably 6 to 12. Here, the number of carbon
atoms within a substituent(s) is not included in the number of
carbon atoms of the aryl group. Specifically a phenyl group or a
naphthyl group is preferable. Examples of the arylalkyl group
include aryl groups in which one or more hydrogen atoms have been
substituted with an alkyl group (preferably an alkyl group of 1 to
5 carbon atoms).
[0190] Examples of the aralkyl group and aryloxoalkyl group for
R.sup.101d to R.sup.101g include a benzyl group, a phenylethyl
group, a phenethyl group, a 2-phenyl-2-oxoethyl group, a
2-(1-naphthyl)-2-oxoethyl group and a 2-(2-naphthyl)-2-oxoethyl
group.
[0191] The hydrogen atoms within the alkyl group, the alkenyl
group, the oxoalkyl group, the oxoalkenyl group, the aryl group,
the arylalkyl group, the aralkyl group and the aryloxoalkyl group
for R.sup.101d to R.sup.101g may or may not be substituted with a
halogen atom such as a fluorine atom, an alkoxy group or a sulfur
atom.
[0192] When R.sup.101d to R.sup.101g are constituted of only a
combination of alkyl groups and hydrogen atoms, in terms of storage
stability and lithography properties, it is preferable that part of
the hydrogen atoms of the alkyl group is substituted with a halogen
atom such as a fluorine atom, an alkoxy group or a sulfur atom.
[0193] Further, R.sup.101d and R.sup.101e, or R.sup.101d,
R.sup.101e and R.sup.101f may be mutually bonded to form a ring
with the nitrogen atom. Examples of the formed ring include a
piperidine ring, a hexamethylene imine ring, an azole ring, a
pyridine ring, a pyrimidine ring, an azepine ring, a pyrazine ring,
a quinoline ring and a benzoquinoline ring.
[0194] Further, the ring may contain an oxygen atom in the ring
skeleton thereof, and specific examples of preferable rings which
contain an oxygen atom include an oxazole ring and an isooxazole
ring.
[0195] Among these examples, as the cation moiety represented by
the aforementioned formula (Glc-1), a nitrogen-containing cation
having a pKa of 7 or less is preferable.
[0196] In the present invention, pKa refers to an acid dissociation
constant which is generally used as a parameter which shows the
acid strength of an objective substance. The pKa value of the
cation of the component (G1) can be determined by a conventional
method. Alternatively, the pKa value can be estimated by
calculation using a conventional software such as "ACD/Labs" (trade
name; manufactured by Advanced Chemistry Development, Inc.).
[0197] The pKa of the component (G1) is preferably 7 or less, and
the pKa value can be appropriately selected depending on the type
and pKa of the counteranion, so that is becomes a weak base
relative to the counteranion. Specifically, the pKa of the cation
is preferably from -2 to 7, more preferably from -1 to 6.5, and
still more preferably 0 to 6. When the pKa is no more than the
upper limit of the above-mentioned range, the basicity of the
cation can be rendered satisfactorily weak, and the component (G1)
itself becomes an acidic compound. Further, when the pKa is at
least as large as the lower limit of the above-mentioned range, a
salt can be more reliably formed with the counteranion, and it
becomes possible to appropriately control the acidity of the
component (G1).
[0198] As a cation which satisfies the above pKa, a cation
represented by any one of the following general formulae (Glc-11)
to (Glc-13) is particularly desirable.
##STR00013##
[0199] In the formulae, Rf.sup.g1 represents a fluorinated alkyl
group of 1 to 12 carbon atoms; Rn.sup.g1 and Rn.sup.g2 each
independently represents a hydrogen atom or an alkyl group of 1 to
5 carbon atoms, provided that Rn.sup.g1 and R.sup.g2 may be
mutually bonded to form a ring; Q.sup.a to Q.sup.c each
independently represents a carbon atom or a nitrogen atom;
Rn.sup.g3 represents a hydrogen atom or a methyl group; Rn.sup.g4
and Rn.sup.g5 each independently represents an aromatic hydrocarbon
group or an alkyl group of 1 to 5 carbon atoms; R.sup.g1 and
R.sup.g2 each independently represents a hydrocarbon group; n15 and
n16 each independently represents an integer of 0 to 4, provided
that, when n15 and n16 is 2 or more, the plurality of R.sup.g1 and
R.sup.g2 which substitute the hydrogen atoms of the adjacent carbon
atom may be bonded to form a ring.
[0200] In formula (Glc-11), Rf.sup.g1 represents a fluorinated
alkyl group of 1 to 12 carbon atoms, and is preferably a
fluorinated alkyl group of 1 to 5 carbon atoms in which 50% or more
of the hydrogen atoms of the alkyl group have been fluorinated.
[0201] In formula (Glc-11), Rn.sup.g1 and Rn.sup.g2 each
independently represents a hydrogen atom or an alkyl group of 1 to
5 carbon atoms, and the alkyl group is the same as defined for the
alkyl groups having 1 to 5 carbon atoms explained above in relation
to the aforementioned formula (Glc-1). Further, in the case where
both Rn.sup.g1 and Rn.sup.g2 represent an alkyl group, the alkyl
groups for Rn.sup.g1 and Rn.sup.g2 may be mutually bonded to form a
ring with NH.sup.+ in the formula.
[0202] In formula (Glc-13), Rn.sup.g4 and Rn.sup.g5 each
independently represents an aromatic hydrocarbon group or an alkyl
group of 1 to 5 carbon atoms. The aromatic hydrocarbon group and
the alkyl group are the same as defined for the aryl group and the
alkyl group of 1 to 5 carbon atoms for R.sup.101d, R.sup.101e,
R.sup.101f and R.sup.101g in the aforementioned formula
(Glc-1).
[0203] In formulae (Glc-12) and (Glc-13), n15 and n16 each
independently represents an integer of 0 to 4, preferably an
integer of 0 to 2, and more preferably 0.
[0204] In formulae (Glc-12) and (Glc-13), R.sup.g1 and R.sup.g2
each independently represents a hydrocarbon group, and is
preferably an alkyl group or alkenyl group of 1 to 12 carbon atoms.
The alkyl group and the alkenyl group are the same as defined for
those described in the explanation of formula (Glc-1).
[0205] When n15 and n16 are 2 or more, the plurality of R.sup.g1
and R.sup.g2 may be the same or different from each other. Further,
when n15 and n16 is 2 or more, the plurality of R.sup.g1 and
R.sup.g2 which substitute the hydrogen atoms of the adjacent carbon
atom may be bonded to form a ring. Examples of the formed ring
include a benzene ring and a naphthalene ring. That is, the
compound represented by formula (Glc-12) or (Glc-13) may be a
condensed ring compound formed by condensation of 2 or more
rings.
[0206] Specific examples of compounds represented by any one of the
aforementioned formulae (Glc-11) to (Glc-13) are shown below.
##STR00014## ##STR00015##
[0207] (Anion Moiety of Component (G1))
[0208] The anion moiety of the component (G1) is not particularly
limited, and any of those generally used the anion moiety of a salt
used in a resist composition may be appropriately selected for
use.
[0209] Among these, as the anion moiety of the component (G1),
those which forms a salt with the aforementioned cation moiety for
the component (G1) to form a component (G1) that exerts the effects
obtained by including the aforementioned component (G) is
preferable.
[0210] That is, the anion moiety of the component (G1) preferably
has a strong acidity. Specifically, the pKa of the anion moiety is
more preferably 0 or less, still more preferably -15 to -1, and
particularly preferably -13 to -3. When the pKa of the anion moiety
is no more than 0, the acidity of the anion can be rendered
satisfactorily strong relative to a cation having a pKa of 7 or
less, and the component (G1) itself becomes an acidic compound. On
the other hand, when the pKa of the anion moiety is -15 or more,
deterioration of the storage stability caused by the component (G1)
being excessively acidic can be prevented.
[0211] As the anion moiety of the component (G1), an anion moiety
having at least one anion group selected from a sulfonate anion, a
carboxylate anion, a sulfonylimide anion, a bis(alkylsulfonyl)imide
anion and a tris(alkylsulfonyl)methide anion is preferable.
[0212] Specific examples include anions represented by general
formula: "R.sup.4''SO.sub.3.sup.- (wherein R.sup.4'' represents a
linear, branched or cyclic alkyl group which may have a
substituent, a halogenated alkyl group, an aryl group or an alkenyl
group)".
[0213] In the aforementioned general formula
"R.sup.4''SO.sub.3.sup.-", R.sup.4'' represents a linear, branched
or cyclic alkyl group which may have a substituent, a halogenated
alkyl group, an aryl group or an alkenyl group.
[0214] The linear or branched alkyl group for the aforementioned
R.sup.4'' preferably has 1 to 10 carbon atoms, more preferably 1 to
8, and most preferably 1 to 4.
[0215] The cyclic alkyl group for the aforementioned R.sup.4''
preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon
atoms, and most preferably 6 to 10 carbon atoms.
[0216] When R.sup.4'' represents an alkyl group, examples of
"R.sup.4''SO.sub.3.sup.-" include alkylsulfonates, such as
methanesulfonate, n-propanesulfonate, n-butanesulfonate,
n-octanesulfonate, 1-adamantanesulfonate, 2-norbornanesulfonate and
d-camphor-10-sulfonate.
[0217] The halogenated alkyl group for the aforementioned R.sup.4''
is an alkyl group in which part or all of the hydrogen atoms
thereof have been substituted with a halogen atom. The alkyl group
preferably has 1 to 5 carbon atoms, and is preferably a linear or
branched alkyl group, and more preferably a methyl group, an ethyl
group, a propyl group, an isopropyl group, an n-butyl group, a
tert-butyl group, a tert-pentyl group or an isopentyl group.
Examples of the halogen atom which substitutes the hydrogen atoms
include a fluorine atom, a chlorine atom, an iodine atom and a
bromine atom. In the halogenated alkyl group, it is preferable that
50 to 100% of all hydrogen atoms within the alkyl group (prior to
halogenation) have been substituted with a halogen atom, and it is
preferable that all hydrogen atoms have been substituted with a
halogen atom.
[0218] As the halogenated alkyl group, a fluorinated alkyl group is
preferable. The fluorinated alkyl group preferably has 1 to 10
carbon atoms, more preferably 1 to 8 carbon atoms, and most
preferably 1 to 4 carbon atoms.
[0219] Further, the fluorination ratio of the fluorinated alkyl
group is preferably from 10 to 100%, more preferably from 50 to
100%, and it is most preferable that all hydrogen atoms are
substituted with fluorine atoms because the acid strength
increases.
[0220] Specific examples of such fluorinated alkyl groups include a
trifluoromethyl group, a heptafluoro-n-propyl group and a
nonafluoro-n-butyl group.
[0221] The aryl group for R.sup.4'' is preferably an aryl group of
6 to 20 carbon atoms.
[0222] The alkenyl group for R.sup.4'' is preferably an alkenyl
group of 2 to 10 carbon atoms.
[0223] With respect to R.sup.4'', the expression "may have a
substituent" means that part of or all of the hydrogen atoms within
the aforementioned linear, branched or cyclic alkyl group,
halogenated alkyl group, aryl group or alkenyl group may be
substituted with substituents (atoms other than hydrogen atoms, or
groups).
[0224] R.sup.4'' may have one substituent, or two or more
substituents.
[0225] Examples of the substituent include a halogen atom, a hetero
atom, an alkyl group, and a group represented by the formula
X.sup.3-Q'- (in the formula, Q' represents a divalent linking group
containing an oxygen atom; and X.sup.3 represents a hydrocarbon
group of 3 to 30 carbon atoms which may have a substituent).
[0226] Examples of halogen atoms and alkyl groups include the same
halogen atoms and alkyl groups as those described above with
respect to the halogenated alkyl group for R.sup.4''.
[0227] Examples of hetero atoms include an oxygen atom, a nitrogen
atom, and a sulfur atom.
[0228] In the group represented by formula X.sup.3-Q'-, Q'
represents a divalent linking group containing an oxygen atom.
[0229] Q' may contain an atom other than an oxygen atom. Examples
of atoms other than oxygen include a carbon atom, a hydrogen atom,
a sulfur atom and a nitrogen atom.
[0230] Examples of divalent linkage groups containing an oxygen
atom include non-hydrocarbon, oxygen atom-containing linkage groups
such as an oxygen atom (an ether bond; --O--), an ester bond
(--C(.dbd.O)--O--), an amide bond (--C(.dbd.O)--NH--), a carbonyl
group (--C(.dbd.O)--) and a carbonate group (--O--C(.dbd.O)--O--);
and a combination of any of the aforementioned non-hydrocarbon,
oxygen atom-containing linkage groups with an alkylene group.
Furthermore, the combinations may have a sulfonyl group
(--SO.sub.2--) bonded thereto.
[0231] Specific examples of the combinations of the aforementioned
non-hydrocarbon, hetero atom-containing linking groups and an
alkylene group include --R.sup.91--O--, --R.sup.92--O--C(.dbd.O)--,
--C(.dbd.O)--O--R.sup.93--O--C(.dbd.O)--,
--SO.sub.2--O--R.sup.94--O--C(.dbd.O)--,
--R.sup.9'--SO.sub.2--O--R.sup.94--O--C(.dbd.O)-- (in the formulas,
each of R.sup.91 to R.sup.95 independently represents an alkylene
group).
[0232] The alkylene group for R.sup.91 to R.sup.95 is preferably a
linear or branched alkylene group, and preferably has 1 to 12
carbon atoms, more preferably 1 to 5, and particularly preferably 1
to 3.
[0233] Specific examples of the alkylene group include a methylene
group [--CH.sub.2--]; alkylmethylene groups such as
--CH(CH.sub.3)--, --CH(CH.sub.2CH.sub.3)--, --C(CH.sub.3).sub.2--,
--C(CH.sub.3)(CH.sub.2CH.sub.3)--,
--C(CH.sub.3)(CH.sub.2CH.sub.2CH.sub.3)-- and
--C(CH.sub.2CH.sub.3).sub.2--; an ethylene group
[--CH.sub.2CH.sub.2--]; alkylethylene groups such as
--CH(CH.sub.3)CH.sub.2--, --CH(CH.sub.3)CH(CH.sub.3)--,
--C(CH.sub.3).sub.2CH.sub.2-- and --CH(CH.sub.2CH.sub.3)CH.sub.2--;
a trimethylene group (n-propylene
group)[--CH.sub.2CH.sub.2CH.sub.2--]; alkyltrimethylene groups such
as --CH(CH.sub.3)CH.sub.2CH.sub.2-- and
--CH.sub.2CH(CH.sub.3)CH.sub.2--; a tetramethylene group
[--CH.sub.2CH.sub.2CH.sub.2CH.sub.2--]; alkyltetramethylene groups
such as --CH(CH.sub.3)CH.sub.2CH.sub.2CH.sub.2-- and
--CH.sub.2CH(CH.sub.3)CH.sub.2CH.sub.2--; and a pentamethylene
group [--CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2--].
[0234] As Q', a divalent linking group containing an ester bond or
an ether bond is preferable, and --R.sup.91--O--,
--R.sup.92--O--C(.dbd.O)-- or
--C(.dbd.O)--O--R.sup.93--O--C(.dbd.O)-- is more preferable.
[0235] In the group represented by the formula X.sup.3-Q'-, X.sup.3
represents a hydrocarbon group of 1 to 30 carbon atoms which may
have a substituent.
[0236] The hydrocarbon group for X.sup.3 may be either an aromatic
hydrocarbon group or an aliphatic hydrocarbon group.
[0237] The aromatic hydrocarbon group is a hydrocarbon group having
an aromatic ring. The aromatic hydrocarbon group preferably has 5
to 30 carbon atoms, more preferably 5 to 20, still more preferably
6 to 15, and most preferably 6 to 12. Here, the number of carbon
atoms within a substituent(s) is not included in the number of
carbon atoms of the aromatic hydrocarbon group.
[0238] Specific examples of aromatic hydrocarbon groups include an
aryl group which is an aromatic hydrocarbon ring having one
hydrogen atom removed therefrom, such as a phenyl group, a biphenyl
group, a fluorenyl group, a naphthyl group, an anthryl group or a
phenanthryl group; and an alkylaryl group such as a benzyl group, a
phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl
group, a 1-naphthylethyl group, or a 2-naphthylethyl group. The
alkyl chain within the arylalkyl group preferably has 1 to 4 carbon
atom, more preferably 1 or 2, and most preferably 1.
[0239] The aromatic hydrocarbon group may have a substituent. For
example, part of the carbon atoms constituting the aromatic ring
within the aromatic hydrocarbon group may be substituted with a
hetero atom, or a hydrogen atom bonded to the aromatic ring within
the aromatic hydrocarbon group may be substituted with a
substituent.
[0240] In the former example, a heteroaryl group in which part of
the carbon atoms constituting the ring within the aforementioned
aryl group has been substituted with a hetero atom such as an
oxygen atom, a sulfur atom or a nitrogen atom, and a
heteroarylalkyl group in which part of the carbon atoms
constituting the aromatic hydrocarbon ring within the
aforementioned arylalkyl group has been substituted with the
aforementioned hetero atom can be used.
[0241] In the latter example, as the substituent for the aromatic
hydrocarbon group, an alkyl group, an alkoxy group, a halogen atom,
a halogenated alkyl group, a hydroxyl group, an oxygen atom
(.dbd.O) or the like can be used.
[0242] The alkyl group as the substituent for the aromatic
hydrocarbon group is preferably an alkyl group of 1 to 5 carbon
atoms, and a methyl group, an ethyl group, a propyl group, an
n-butyl group or a tert-butyl group is particularly desirable.
[0243] The alkoxy group as the substituent for the aromatic
hydrocarbon group is preferably an alkoxy group having 1 to 5
carbon atoms, more preferably a methoxy group, an ethoxy group, an
n-propoxy group, an iso-propoxy group, an n-butoxy group or a
tert-butoxy group, and most preferably a methoxy group or an ethoxy
group.
[0244] Examples of the halogen atom as the substituent for the
aromatic hydrocarbon group include a fluorine atom, a chlorine
atom, a bromine atom and an iodine atom, and a fluorine atom is
preferable.
[0245] Example of the halogenated alkyl group as the substituent
for the aromatic hydrocarbon group includes a group in which part
or all of the hydrogen atoms within the aforementioned alkyl group
have been substituted with the aforementioned halogen atoms.
[0246] The aliphatic hydrocarbon group for X.sup.3 may be either a
saturated aliphatic hydrocarbon group, or an unsaturated aliphatic
hydrocarbon group. Further, the aliphatic hydrocarbon group may be
linear, branched or cyclic.
[0247] In the aliphatic hydrocarbon group for X.sup.3, part of the
carbon atoms constituting the aliphatic hydrocarbon group may be
substituted with a substituent group containing a hetero atom, or
part or all of the hydrogen atoms constituting the aliphatic
hydrocarbon group may be substituted with a substituent group
containing a hetero atom.
[0248] As the "hetero atom" for X.sup.3, there is no particular
limitation as long as it is an atom other than carbon and hydrogen.
Examples of hetero atoms include a halogen atom, an oxygen atom, a
sulfur atom and a nitrogen atom. Examples of the halogen atom
include a fluorine atom, a chlorine atom, an iodine atom and a
bromine atom.
[0249] The substituent group containing a hetero atom may consist
of a hetero atom, or may be a group containing a group or atom
other than a hetero atom.
[0250] Specific examples of the substituent group for substituting
a part of the carbon atoms include --O--, --C(.dbd.O)--O--,
--C(.dbd.O)--, --O--C(.dbd.O)--O--, --C(.dbd.O)--NH--, --NH-- (the
H may be substituted with a substituent such as an alkyl group or
an acyl group), --S--, --S(.dbd.O).sub.2-- and
--S(.dbd.O).sub.2--O--. When the aliphatic hydrocarbon group is
cyclic, the aliphatic hydrocarbon group may contain any of these
substituent groups in the ring structure.
[0251] Examples of the substituent group for substituting part or
all of the hydrogen atoms include an alkoxy group, a halogen atom,
a halogenated alkyl group, a hydroxyl group, an oxygen atom
(.dbd.O) and a cyano group.
[0252] The aforementioned alkoxy group is preferably an alkoxy
group having 1 to 5 carbon atoms, more preferably a methoxy group,
an ethoxy group, an n-propoxy group, an iso-propoxy group, an
n-butoxy group or a tert-butoxy group, and most preferably a
methoxy group or an ethoxy group.
[0253] Examples of the aforementioned halogen atom include a
fluorine atom, a chlorine atom, a bromine atom and an iodine atom,
and a fluorine atom is preferable.
[0254] Example of the aforementioned halogenated alkyl group
includes a group in which a part or all of the hydrogen atoms
within an alkyl group of 1 to 5 carbon atoms (e.g., a methyl group,
an ethyl group, a propyl group, an n-butyl group or a tert-butyl
group) have been substituted with the aforementioned halogen
atoms.
[0255] As the aliphatic hydrocarbon group, a linear or branched
saturated hydrocarbon group, a linear or branched monovalent
unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon
group (aliphatic cyclic group) is preferable.
[0256] The linear saturated hydrocarbon group (alkyl group)
preferably has 1 to 20 carbon atoms, more preferably 1 to 15, and
most preferably 1 to 10. Specific examples include a methyl group,
an ethyl group, a propyl group, a butyl group, a pentyl group, a
hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl
group, an undecyl group, a dodecyl group, a tridecyl group, an
isotridecyl group, a tetradecyl group, a pentadecyl group, a
hexadecyl group, an isohexadecyl group, a heptadecyl group, an
octadecyl group, a nonadecyl group, an icosyl group, a henicosyl
group and a docosyl group.
[0257] The branched saturated hydrocarbon group (alkyl group)
preferably has 3 to 20 carbon atoms, more preferably 3 to 15, and
most preferably 3 to 10. Specific examples include a 1-methylethyl
group, a 1-methylpropyl group, a 2-methylpropyl group, a
1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group,
a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group,
a 2-methylpentyl group, a 3-methylpentyl group and a 4-methylpentyl
group.
[0258] The unsaturated hydrocarbon group preferably has 2 to 10
carbon atoms, more preferably 2 to 5, still more preferably 2 to 4,
and particularly preferably 3. Examples of linear monovalent
unsaturated hydrocarbon groups include a vinyl group, a propenyl
group (an allyl group) and a butynyl group. Examples of branched
monovalent unsaturated hydrocarbon groups include a
1-methylpropenyl group and a 2-methylpropenyl group.
[0259] Among the above-mentioned examples, as the unsaturated
hydrocarbon group, a propenyl group is particularly desirable.
[0260] The aliphatic cyclic group may be either a monocyclic group
or a polycyclic group. The aliphatic cyclic group preferably has 3
to 30 carbon atoms, more preferably 5 to 30, still more preferably
5 to 20, particularly preferably 6 to 15, and most preferably 6 to
12.
[0261] Examples thereof include groups in which one or more of the
hydrogen atoms have been removed from a monocycloalkane; and groups
in which one or more of the hydrogen atoms have been removed from a
polycycloalkane such as a bicycloalkane, a tricycloalkane, or a
tetracycloalkane. Specific examples include groups in which one or
more hydrogen atoms have been removed from a monocycloalkane such
as cyclopentane or cyclohexane; and groups in which one or more
hydrogen atoms have been removed from a polycycloalkane such as
adamantane, norbornane, isobornane, tricyclodecane or
tetracyclododecane.
[0262] When the aliphatic cyclic group does not contain a hetero
atom-containing substituent group in the ring structure thereof,
the aliphatic cyclic group is preferably a polycyclic group, more
preferably a group in which one or more hydrogen atoms have been
removed from a polycycloalkane, and a group in which one or more
hydrogen atoms have been removed from adamantane is particularly
desirable.
[0263] When the aliphatic cyclic group contains a hetero
atom-containing substituent group in the ring structure thereof,
the hetero atom-containing substituent group is preferably --O--,
--C(.dbd.O)--O--, --S--, --S(.dbd.O).sub.2-- or
--S(.dbd.O).sub.2--O--. Specific examples of such aliphatic cyclic
groups include groups represented by formulas (L1) to (L6) and (S1)
to (S4) shown below.
##STR00016## ##STR00017##
[0264] In the formulas, Q'' represents an alkylene group of 1 to 5
carbon atoms, --O--, --S--, --O--R.sup.94-- or --S--R.sup.95--
(R.sup.94 and R.sup.95 each independently represent an alkylene
group of 1 to 5 carbon atoms); and m represents 0 or 1.
[0265] As the alkylene group for Q'', R.sup.94 and R.sup.95, the
same alkylene groups as those described above for R.sup.91 to
R.sup.93 can be used.
[0266] In these aliphatic cyclic groups, part of the hydrogen atoms
bonded to the carbon atoms constituting the ring structure may be
substituted with a substituent. Examples of substituents include an
alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl
group, a hydroxyl group and an oxygen atom (.dbd.O).
[0267] As the alkyl group, an alkyl group of 1 to 5 carbon atoms is
preferable, and a methyl group, an ethyl group, a propyl group, an
n-butyl group or a tert-butyl group is particularly desirable.
[0268] As the alkoxy group and the halogen atom, the same groups as
the substituent groups for substituting part or all of the hydrogen
atoms can be used.
[0269] As X.sup.3, a cyclic group which may have a substituent is
preferable. The cyclic group may be either an aromatic hydrocarbon
group which may have a substituent, or a cyclic alkyl group which
may have a substituent, and an aliphatic cyclic group which may
have a substituent is preferable.
[0270] As the aromatic hydrocarbon group, a naphthyl group which
may have a substituent, or a phenyl group which may have a
substituent is preferable. As the substituent, a fluorine atom is
preferable.
[0271] As the cyclic aliphatic group which may have a substituent,
a polycyclic alkyl group which may have a substituent is
preferable. As the polycyclic alkyl group, the aforementioned group
in which one or more hydrogen atoms have been removed from a
polycycloalkane, and groups represented by formulas (L2) to (L7),
(S3) and (S4) are preferable.
[0272] Among these examples, as the aforementioned R.sup.4'', a
halogenated alkyl group or a group having X.sup.3-Q'- as a
substituent is preferable.
[0273] When the R.sup.4'' group has X.sup.3-Q'- as a substituent,
as R.sup.4'', a group represented by the formula:
X.sup.3-Q'-Y.sup.3-- (in the formula, Q' and X.sup.3 are the same
as defined above, and Y.sup.3 represents an alkylene group of 1 to
4 carbon atoms which may have a substituent or a fluorinated
alkylene group of 1 to 4 carbon atoms which may have a substituent
is preferable.
[0274] In the group represented by the formula
X.sup.3-Q'-Y.sup.3--, as the alkylene group for Y.sup.3, the same
alkylene group as those described above for Q' in which the number
of carbon atoms is 1 to 4 can be used.
[0275] As the fluorinated alkylene group, the aforementioned
alkylene group in which part or all of the hydrogen atoms has been
substituted with fluorine atoms can be used.
[0276] Specific examples of Y.sup.3 include --CF.sub.2--,
--CF.sub.2CF.sub.2--, --CF.sub.2CF.sub.2CF.sub.2--,
--CF(CF.sub.3)CF.sub.2--, --CF(CF.sub.2CF.sub.3)--,
--C(CF.sub.3).sub.2--, --CF.sub.2CF.sub.2CF.sub.2CF.sub.2--,
--CF(CF.sub.3)CF.sub.2CF.sub.2--, --CF.sub.2CF(CF.sub.3)CF.sub.2--,
--CF(CF.sub.3)CF(CF.sub.3)--, --C(CF.sub.3).sub.2CF.sub.2--,
--CF(CF.sub.2CF.sub.3)CF.sub.2--, --CF(CF.sub.2CF.sub.2CF.sub.3)--,
--C(CF.sub.3)(CF.sub.2CF.sub.3)--; --CHF--, --CH.sub.2CF.sub.2--,
--CH.sub.2CH.sub.2CF.sub.2--, --CH.sub.2CF.sub.2CF.sub.2--,
--CH(CF.sub.3)CH.sub.2--, --CH(CF.sub.2CF.sub.3)--,
--C(CH.sub.3)(CF.sub.3)--, --CH.sub.2CH.sub.2CH.sub.2CF.sub.2--,
--CH.sub.2CH.sub.2CF.sub.2CF.sub.2--,
--CH(CF.sub.3)CH.sub.2CH.sub.2--, --CH.sub.2CH(CF.sub.3)CH.sub.2--,
--CH(CF.sub.3)CH(CF.sub.3)--, --C(CF.sub.3).sub.2CH.sub.2--;
--CH.sub.2--, --CH.sub.2CH.sub.2--, --CH.sub.2CH.sub.2CH.sub.2--,
--CH(CH.sub.3)CH.sub.2--, --CH(CH.sub.2CH.sub.3)--,
--C(CH.sub.3).sub.2--, --CH.sub.2CH.sub.2CH.sub.2CH.sub.2--,
--CH(CH.sub.3)CH.sub.2CH.sub.2--, --CH.sub.2CH(CH.sub.3)CH.sub.2--,
--CH(CH.sub.3)CH(CH.sub.3)--, --C(CH.sub.3).sub.2CH.sub.2--,
--CH(CH.sub.2CH.sub.3)CH.sub.2--, --CH(CH.sub.2CH.sub.2CH.sub.3)--
and --C(CH.sub.3)(CH.sub.2CH.sub.3)--.
[0277] As Y.sup.3, a fluorinated alkylene group is preferable, and
a fluorinated alkylene group in which the carbon atom bonded to the
adjacent sulfur atom is fluorinated is particularly desirable.
Examples of such fluorinated alkylene groups include --CF.sub.2--,
--CF.sub.2CF.sub.2--, --CF.sub.2CF.sub.2CF.sub.2--,
--CF(CF.sub.3)CF.sub.2--, --CF.sub.2CF.sub.2CF.sub.2CF.sub.2--,
--CF(CF.sub.3)CF.sub.2CF.sub.2--, --CF.sub.2CF(CF.sub.3)CF.sub.2--,
--CF(CF.sub.3)CF(CF.sub.3)--, --C(CF.sub.3).sub.2CF.sub.2--,
--CF(CF.sub.2CF.sub.3)CF.sub.2--; --CH.sub.2CF.sub.2--,
--CH.sub.2CH.sub.2CF.sub.2--, --CH.sub.2CF.sub.2CF.sub.2--;
--CH.sub.2CH.sub.2CH.sub.2CF.sub.2--,
--CH.sub.2CH.sub.2CF.sub.2CF.sub.2-- and
--CH.sub.2CF.sub.2CF.sub.2CF.sub.2--. Of these, --CF.sub.2--,
--CF.sub.2CF.sub.2--, --CF.sub.2CF.sub.2CF.sub.2-- or
CH.sub.2CF.sub.2CF.sub.2-- is preferable, --CF.sub.2--,
--CF.sub.2CF.sub.2-- or --CF.sub.2CF.sub.2CF.sub.2-- is more
preferable, and --CF.sub.2-- is particularly preferable.
[0278] The alkylene group or fluorinated alkylene group may have a
substituent. The alkylene group or fluorinated alkylene group "has
a substituent" means that part or all of the hydrogen atoms or
fluorine atoms in the alkylene group or fluorinated alkylene group
has been substituted with groups other than hydrogen atoms and
fluorine atoms.
[0279] Examples of substituents which the alkylene group or
fluorinated alkylene group may have include an alkyl group of 1 to
4 carbon atoms, an alkoxy group of 1 to 4 carbon atoms, and a
hydroxyl group.
[0280] Specific examples of groups represented by formula
R.sup.4''SO.sub.3.sup.- in which R.sup.4'' represents
X.sup.3-Q'-Y.sup.3-- include anions represented by the following
formulae (b1) to (b9).
##STR00018##
[0281] In the formulae, q1 and q2 each independently represents an
integer of 1 to 5; q3 represents an integer of 1 to 12; t3
represents an integer of 1 to 3; r1 and r2 each independently
represents an integer of 0 to 3; g represents an integer of 1 to
20; R.sup.7 represents a substituent; n1 to n6 each independently
represents 0 or 1; v0 to v6 each independently represents an
integer of 0 to 3; w1 to w6 each independently represents an
integer of 0 to 3; and Q'' is the same as defined above.
[0282] As the substituent for R.sup.7, the same groups as those
which the aforementioned aliphatic hydrocarbon group or aromatic
hydrocarbon group for X.sup.3 may have as a substituent can be
used.
[0283] If there are two or more of the R.sup.7 group, as indicated
by the values r1, r2, and w1 to w6, then the two or more of the
R.sup.7 groups may be the same or different from each other.
[0284] Further, as preferable examples of the anion moiety of the
component (G1), an anion represented by general formula (Gla-3)
shown below and an anion moiety represented by general formula
(Gla-4) shown below can also be mentioned.
##STR00019##
[0285] In the formulas, X'' represents an alkylene group of 2 to 6
carbon atoms in which at least one hydrogen atom has been
substituted with a fluorine atom; and Y'' and Z'' each
independently represents an alkyl group of 1 to 10 carbon atoms in
which at least one hydrogen atom has been substituted with a
fluorine atom.
[0286] In formula (Gla-3), X'' represents a linear or branched
alkylene group in which at least one hydrogen atom has been
substituted with a fluorine atom, and the alkylene group preferably
has 2 to 6 carbon atoms, more preferably 3 to 5 carbon atoms, and
most preferably 3 carbon atoms.
[0287] In formula (Gla-4), each of Y'' and Z'' independently
represents a linear or branched alkyl group in which at least one
hydrogen atom has been substituted with a fluorine atom, and the
alkyl group preferably has 1 to 10 carbon atoms, more preferably 1
to 7 carbon atoms, and most preferably 1 to 3 carbon atoms.
[0288] The smaller the number of carbon atoms of the alkylene group
for X'' or those of the alkyl group for Y'' and Z'' within the
above-mentioned range of the number of carbon atoms, the more the
solubility in a resist solvent is improved.
[0289] Further, in the alkylene group for X'' or the alkyl group
for Y'' and Z'', it is preferable that the number of hydrogen atoms
substituted with fluorine atoms is as large as possible because the
acid strength increases and the transparency to high energy
radiation of 200 nm or less or electron beam is improved.
[0290] The amount of fluorine atoms within the alkylene group or
alkyl group, i.e., fluorination ratio, is preferably from 70 to
100%, more preferably from 90 to 100%, and it is particularly
desirable that the alkylene group or alkyl group be a
perfluoroalkylene or perfluoroalkyl group in which all hydrogen
atoms are substituted with fluorine atoms.
[0291] As the anion moiety of the component (G1), an anion
represented by the aforementioned formula "R.sup.4''SO.sub.3.sup.-"
(in particular, any one of anions represented by the aforementioned
formulae (b1) to (b9) which is a group in which R.sup.4'' is
"X.sup.3-Q'-Y.sup.3--") or an anion represented by the
aforementioned formula (Gla-3) is most preferable.
[0292] As the component (G1), one type of compound may be used
alone, or two or more types may be used in combination.
[0293] In the undercoat agent, the amount of the component (G1)
within the component (G) is preferably 40% by weight or more, still
more preferably 70% by weight or more, and may be even 100% by
weight. When the amount of the component (G1) is at least as large
as the lower limit of the above-mentioned range, the effects of the
present invention are improved.
[0294] In the undercoat agent, the amount of the component (G1),
relative to 100 parts by weight of the component (A) is preferably
from 0.5 to 30 parts by weight, more preferably from 1 to 20 parts
by weight, and most preferably from 2 to 15 parts by weight. When
the amount of the component (G1) is within the above-mentioned
range, the effects of the present invention are improved.
[0295] [Component (G2)]
[0296] The component (G2) is a component which does not fall under
the definition of the component (G1), and the component (G2) itself
exhibits acidity, so as to act as a proton donor. Examples of the
component (G2) include a non-ionic acid which does not form a
salt.
[0297] As the component (G2), there is no particular limitation,
and as the component (G2), an imine acid or a sulfonic acid
compound is preferable, and examples thereof include sulfonylimide,
bis(alkylsulfonyl)imide, tris(alkylsulfonyl)methide, and any of
these compounds which have a fluorine atom.
[0298] In particular, a compound represented by any one of general
formulae (G2-1) to (G2-3) shown below (preferably a compound
represented by general formula (G2-2)), a compound in which an
anion represented by any one of general formulae (b1) to (b9)
described above has "--SO.sub.3.sup.-" replaced by "--SO.sub.3H", a
compound in which an anion represented by general formula (Gla-3)
or (Gla-4) described above has "N" replaced by "NH", and
camphorsulfonic acid are preferable. Other examples include acid
components such as a fluorinated alkyl group-containing carboxylic
acid, a higher fatty acid, a higher alkylsulfonic acid, and a
higher alkylarylsulfonic acid.
##STR00020##
[0299] In formula (G2-1), w' represents an integer of 1 to 5. In
formula (G2-2), R.sup.f represents a hydrogen atom or an alkyl
group (provided that part or all of the hydrogen atoms within the
alkyl group may be substituted with a fluorine atom, a hydroxy
group, an alkoxy group, a carboxy group or an amino group); and y'
represents 2 or 3. In formula (G2-3), R.sup.f is the same as
defined above; and z' represents 2 or 3.
[0300] Examples of compounds represented by the aforementioned
formula (G2-1) include (C.sub.4F.sub.9SO.sub.2).sub.2NH and
(C.sub.3F.sub.7SO.sub.2).sub.2NH.
[0301] In the aforementioned formula (G2-2), the alkyl group for
R.sup.f preferably has 1 or 2 carbon atoms, and more preferably
1.
[0302] Examples of the alkoxy group which may substitute the
hydrogen atom(s) within the alkyl group include a methoxy group and
an ethoxy group.
[0303] Examples of a compound represented by the aforementioned
formula (G2-2) include a compound represented by a chemical formula
(G2-21) shown below.
##STR00021##
[0304] In the aforementioned formula (G2-3), R.sup.f is the same as
defined for R.sup.f in formula (G2-2).
[0305] Examples of a compound represented by the aforementioned
formula (G2-3) include a compound represented by a chemical formula
(G2-31) shown below.
##STR00022##
[0306] As the fluorinated alkyl group-containing carboxylic group,
for example, C.sub.10F.sub.21COOH can be mentioned.
[0307] Examples of the higher fatty acid include higher fatty acids
having an alkyl group of 8 to 20 carbon atoms, and specific
examples thereof include dodecanoic acid, tetradecanoic acid, and
stearic acid.
[0308] The alkyl group of 8 to 20 carbon atoms may be either linear
or branched. Further, the alkyl group of 8 to 20 carbon atoms may
have a phenylene group, an oxygen atom or the like interposed
within the chain thereof. Furthermore, the alkyl group of 8 to 20
carbon atoms may have part of the hydrogen atoms substituted with a
hydroxy group or a carboxy group.
[0309] Examples of the higher alkylsulfonic acid include sulfonic
acids having an alkyl group preferably with an average of 9 to 21
carbon atoms, more preferably 12 to 18 carbon atoms, and specific
examples thereof include decanesulfonic acid, dodecanesulfonic
acid, tetradecanesulfonic acid, pentadecanesulfonic acid and
octadecanesulfonic acid.
[0310] Examples of the higher alkylarylsulfonic acid include
alkylbenzenesulfonic acids and alkylnaphthalenesulfonic acids
having an alkyl group preferably with an average of 6 to 18 carbon
atoms, more preferably 9 to 15 carbon atoms, and specific examples
thereof include dodecylbenzenesulfonic acid and
decylnaphthalenesulfonic acid.
[0311] Examples of the acid components include
alkyldiphenyletherdisulfonic acids preferably with an average of 6
to 18 carbon atoms, more preferably 9 to 15, and preferable
examples thereof include dodecyldiphenyletherdisulfonic acid.
[0312] Examples of the component (G2) other than those described
above include organic carboxylic acid, a phosphorus oxo acid or
derivative thereof.
[0313] Examples of suitable organic carboxylic acids include acetic
acid, malonic acid, citric acid, malic acid, succinic acid, benzoic
acid, and salicylic acid.
[0314] Examples of phosphorus oxo acids include phosphoric acid,
phosphonic acid and phosphinic acid. Among these, phosphonic acid
is particularly desirable.
[0315] Examples of phosphorous oxo acid derivatives include esters
in which a hydrogen atom within the above-mentioned oxo acids is
substituted with a hydrocarbon group. Examples of the hydrocarbon
group include an alkyl group of 1 to 5 carbon atoms and an aryl
group of 6 to 15 carbon atoms.
[0316] Examples of phosphoric acid derivatives include phosphoric
acid esters such as di-n-butyl phosphate and diphenyl
phosphate.
[0317] Examples of phosphonic acid derivatives include phosphonic
acid esters such as dimethyl phosphonate, di-n-butyl phosphonate,
phenyl phosphonate, diphenyl phosphonate and dibenzyl
phosphonate.
[0318] Examples of phosphinic acid derivatives include phosphinic
acid esters such as phenylphosphinic acid.
[0319] When the component (G) includes a component (G2), as the
component (G2), one type of compound may be used, or two or more
types may be used in combination. Among these, as the component
(G2), at least one member selected from the group consisting of
sulfonylimide, bis(alkylsulfonyl)imide, tris(alkylsulfonyl)methide
and any of these compounds having a fluorine atom is preferable,
and it is most preferable to use at least one of these compounds
having a fluorine atom.
[0320] Further, when the undercoat agent contains the component
(G2), the amount of the component (G2) relative to 100 parts by
weight of the component (A) is preferably within a range from 0.5
to 20 parts by weight, more preferably from 1 to 15 parts by
weight, and still more preferably from 1 to 10 parts by weight.
When the amount of the component (G2) is within the above-mentioned
range, the effects of the present invention are improved.
[0321] [Acid Generator Component; Component (B)]
[0322] The undercoat agent of the present invention may further
include an acid generator component (B) (hereafter, frequently
referred to as "component (B)"). Differing from the component (G),
the component (B) generates acid upon heating or exposure. The
component (B) itself does not need to exhibit acidity, and is
decomposed by heat or light, so as to function as acid.
[0323] As the component (B), there is no particular limitation, and
any of the known acid generators used in conventional chemically
amplified resist compositions can be used.
[0324] As the acid generator, a thermal acid generator which
generates acid upon heating and a photoacid generator which
generates acid upon exposure can be mentioned. Examples of such
acid generators are numerous, and include onium salt acid
generators such as iodonium salts and sulfonium salts; oxime
sulfonate acid generators; diazomethane acid generators such as
bisalkyl or bisaryl sulfonyl diazomethanes and
poly(bis-sulfonyl)diazomethanes; nitrobenzylsulfonate acid
generators; iminosulfonate acid generators; and disulfone acid
generators.
[0325] These acid generator components are generally known as
photoacid generators (PAG), but also function as thermal acid
generators (TAG). Therefore, the acid generator component usable in
the present invention can be appropriately selected from those
which have been conventionally known as acid generators for
chemically amplified resist compositions.
[0326] A "thermal acid generator which generates acid upon heating"
refers to a component which generates acid upon heating, i.e.,
200.degree. C. or lower, and more preferably at 50 to 150.degree.
C. By selecting a component which generates acid at 200.degree. C.
or higher, controlling generation of acid becomes easy. More
preferably, by selecting a component which generates acid at
50.degree. C. or higher, the stability in the undercoat agent
becomes excellent.
[0327] As the onium salt acid generator for the component (B),
those which have at least one anion group selected from a sulfonate
anion, a carboxylate anion, a sulfonylimide anion, a
bis(alkylsulfonyl)imide anion, a tris(alkylsulfonyl)methide anion
and a fluorinated antimonic acid ion within the anion moiety is
preferable. More specifically, the same anion moieties as those
described above for the component (G1), and hexafluoroantimonic
acid ion can be mentioned.
[0328] Further, as the cation moiety, a cation moiety represented
by general formula (b-c1) or (b-c2) shown below is preferable.
##STR00023##
[0329] In the formulae, R.sup.1'' to R.sup.3'', R.sup.5'' and
R.sup.6'' each independently represents an aryl group which may
have a substituent, an alkyl group which may have a substituent or
an alkenyl group which may have a substituent, provided that, in
formula (b-1), two of R.sup.1'' to R.sup.3'' may be mutually bonded
to form a ring with the sulfur atom.
[0330] In formula (b-1), R.sup.1'' to R.sup.3''each independently
represents an aryl group which may have a substituent, an alkyl
group which may have a substituent or an alkenyl group which may
have a substituent. Two of R.sup.1'' to R.sup.3'' may be mutually
bonded to form a ring with the sulfur atom.
[0331] Examples of the aryl group for R.sup.1'' to R.sup.3''
include an unsubstituted aryl group of 6 to 20 carbon atoms; a
substituted aryl group in which part or all of the hydrogen atoms
of the aforementioned unsubstituted aryl group has been substituted
with an alkyl group, an alkoxy group, a halogen atom, a hydroxy
group, an oxo group (.dbd.O), an aryl group, an alkoxyalkyloxy
group, an alkoxycarbonylalkyloxy group, --C(.dbd.O)--O--R.sup.6',
--O--C(.dbd.O)--R.sup.7' or --O--R.sup.8'. Each of R.sup.6',
R.sup.7' and R.sup.8' independently represents a linear or branched
saturated hydrocarbon group of 1 to 25 carbon atoms, a cyclic
saturated hydrocarbon group of 3 to 20 carbon atoms or a linear or
branched, aliphatic unsaturated hydrocarbon group of 2 to 5 carbon
atoms.
[0332] The unsubstituted aryl group for R.sup.1'' to R.sup.3'' is
preferably an aryl group having 6 to 10 carbon atoms because it can
be synthesized at a low cost. Specific examples thereof include a
phenyl group and a naphthyl group.
[0333] The alkyl group as the substituent for the substituted aryl
group represented by R.sup.1'' to R.sup.3'' is preferably an alkyl
group having 1 to 5 carbon atoms, and a methyl group, an ethyl
group, a propyl group, an n-butyl group, or a tert-butyl group is
particularly desirable.
[0334] The alkoxy group as the substituent for the substituted aryl
group is preferably an alkoxy group having 1 to 5 carbon atoms, and
a methoxy group, an ethoxy group, an n-propoxy group, an
iso-propoxy group, an n-butoxy group or a tert-butoxy group is
particularly desirable.
[0335] The halogen atom as the substituent for the substituted aryl
group is preferably a fluorine atom.
[0336] As the aryl group as the substituent for the substituted
aryl group, the same aryl groups as those described for R.sup.1''
to R.sup.3'' can be mentioned.
[0337] Examples of alkoxyalkyloxy groups as the substituent for the
substituted aryl group include groups represented by a general
formula shown below:
--O--C(R.sup.47)(R.sup.48)--O--R.sup.49.
[0338] In the formula, R.sup.47 and R.sup.48 each independently
represents a hydrogen atom or a linear or branched alkyl group; and
R.sup.49 represents an alkyl group.
[0339] The alkyl group for R.sup.47 and R.sup.48 preferably has 1
to 5 carbon atoms, and may be either linear or branched, and is
preferably an ethyl group or a methyl group, and most preferably a
methyl group.
[0340] It is preferable that at least one of R.sup.47 and R.sup.48
be a hydrogen atom. It is particularly desirable that at least one
of R.sup.47 and R.sup.48 be a hydrogen atom, and the other be a
hydrogen atom or a methyl group.
[0341] The alkyl group for R.sup.49 preferably has 1 to 15 carbon
atoms, and may be linear, branched or cyclic.
[0342] The linear or branched alkyl group for R.sup.49 preferably
has 1 to 5 carbon atoms. Examples thereof include a methyl group,
an ethyl group, a propyl group, an n-butyl group and a tert-butyl
group.
[0343] The cyclic alkyl group for R.sup.49 preferably has 4 to 15
carbon atoms, more preferably 4 to 12, and most preferably 5 to 10.
Specific examples thereof include groups in which one or more
hydrogen atoms have been removed from a monocycloalkane or a
polycycloalkane such as a bicycloalkane, tricycloalkane or
tetracycloalkane, and which may or may not be substituted with an
alkyl group of 1 to 5 carbon atoms, a fluorine atom or a
fluorinated alkyl group. Examples of the monocycloalkane include
cyclopentane and cyclohexane. Examples of polycycloalkanes include
adamantane, norbornane, isobornane, tricyclodecane and
tetracyclododecane. Among these, a group in which one or more
hydrogen atoms have been removed from adamantane is preferable.
[0344] Examples of the alkoxycarbonylalkyloxy group as the
substituent for the substituted aryl group include groups
represented by a general formula shown below:
--O--R.sup.50--C(.dbd.O)--O--R.sup.56.
[0345] In the formula, R.sup.50 represents a linear or branched
alkylene group, and R.sup.56 represents a tertiary alkyl group.
[0346] The linear or branched alkylene group for R.sup.50
preferably has 1 to 5 carbon atoms, and examples thereof include a
methylene group, an ethylene group, a trimethylene group, a
tetramethylene group and a 1,1-dimethylethylene group.
[0347] The alkyl group for R.sup.56 is a tertiary alkyl group, and
examples thereof include a 2-methyl-2-adamantyl group, a
2-ethyl-2-adamantyl group, a 1-methyl-1-cyclopentyl group, a
1-ethyl-1-cyclopentyl group, a 1-methyl-1-cyclohexyl group, a
1-ethyl-1-cyclohexyl group, a 1-(1-adamantyl)-1-methylethyl group,
a 1-(1-adamantyl)-1-methylpropyl group, a
1-(1-adamantyl)-1-methylbutyl group, a
1-(1-adamantyl)-1-methylpentyl group, a
1-(1-cyclopentyl)-1-methylethyl group, a
1-(1-cyclopentyl)-1-methylpropyl group, a
1-(1-cyclopentyl)-1-methylbutyl group, a
1-(1-cyclopentyl)-1-methylpentyl group, a
1-(1-cyclohexyl)-1-methylethyl group, a
1-(1-cyclohexyl)-1-methylpropyl group, a
1-(1-cyclohexyl)-1-methylbutyl group, a
1-(1-cyclohexyl)-1-methylpentyl group, a tert-butyl group, a
tert-pentyl group and a tert-hexyl group.
[0348] Further, a group in which R.sup.56 in the group represented
by the aforementioned general formula:
O--R.sup.50--C(.dbd.O)--O--R.sup.6 has been substituted with
R.sup.56' can also be mentioned. R.sup.56' represents a hydrogen
atom, an alkyl group, a fluorinated alkyl group or an aliphatic
cyclic group which may contain a hetero atom.
[0349] The alkyl group for R.sup.56' is the same as defined for the
alkyl group for the aforementioned R.sup.49.
[0350] Examples of the fluorinated alkyl group for R.sup.56'
include groups in which part or all of the hydrogen atoms within
the alkyl group for R.sup.49 has been substituted with a fluorine
atom.
[0351] Examples of the aliphatic cyclic group for R.sup.56' which
may contain a hetero atom include an aliphatic cyclic group which
does not contain a hetero atom, an aliphatic cyclic group
containing a hetero atom in the ring structure, and an aliphatic
cyclic group in which a hydrogen atom has been substituted with a
hetero atom.
[0352] As an aliphatic cyclic group for R.sup.56' which does not
contain a hetero atom, a group in which one or more hydrogen atoms
have been removed from a monocycloalkane or a polycycloalkane such
as a bicycloalkane, a tricycloalkane or a tetracycloalkane can be
mentioned. Examples of the monocycloalkane include cyclopentane and
cyclohexane. Examples of polycycloalkanes include adamantane,
norbornane, isobornane, tricyclodecane and tetracyclododecane.
Among these, a group in which one or more hydrogen atoms have been
removed from adamantane is preferable.
[0353] Specific examples of the aliphatic cyclic group for
R.sup.56' containing a hetero atom in the ring structure include
groups represented by the aforementioned formulae (L1) to (L6) and
(S1) to (S4).
[0354] As the aliphatic cyclic group for R.sup.56' in which a
hydrogen atom has been substituted with a hetero atom, an aliphatic
cyclic group in which a hydrogen atom has been substituted with an
oxygen atom (.dbd.O) can be mentioned.
[0355] In formulae --C(.dbd.O)--O--R.sup.6',
--O--C(.dbd.O)--R.sup.7' and --O--R.sup.8', R.sup.6', R.sup.7' and
R.sup.8' each independently represents a linear or branched
saturated hydrocarbon group of 1 to 25 atoms, a cyclic saturated
hydrocarbon group of 3 to 20 carbon atoms or a linear or branched,
aliphatic unsaturated hydrocarbon group of 2 to 5 carbon atoms.
[0356] The linear or branched, saturated hydrocarbon group
preferably has 1 to 25 carbon atoms, more preferably 1 to 15, and
still more preferably 4 to 10.
[0357] Examples of the linear, saturated hydrocarbon group include
a methyl group, an ethyl group, a propyl group, a butyl group, a
pentyl group, a hexyl group, a heptyl group, an octyl group, a
nonyl group and a decyl group.
[0358] Examples of the branched, saturated hydrocarbon group
include a 1-methylethyl group, a 1-methylpropyl group, a
2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group,
a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group,
a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl
group and a 4-methylpentyl group, but excluding tertiary alkyl
groups.
[0359] The linear or branched, saturated hydrocarbon group may have
a substituent. Examples of the substituent include an alkoxy group,
a halogen atom, a halogenated alkyl group, a hydroxyl group, an
oxygen atom (.dbd.O), a cyano group and a carboxy group.
[0360] The alkoxy group as the substituent for the linear or
branched saturated hydrocarbon group is preferably an alkoxy group
having 1 to 5 carbon atoms, more preferably a methoxy group, an
ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy
group or a tert-butoxy group, and most preferably a methoxy group
or an ethoxy group.
[0361] Examples of the halogen atom as the substituent for the
linear or branched, saturated hydrocarbon group include a fluorine
atom, a chlorine atom, a bromine atom and an iodine atom, and a
fluorine atom is preferable.
[0362] Example of the halogenated alkyl group as the substituent
for the linear or branched, saturated hydrocarbon group includes a
group in which part or all of the hydrogen atoms within the
aforementioned linear or branched, saturated hydrocarbon group have
been substituted with the aforementioned halogen atoms.
[0363] The cyclic saturated hydrocarbon group of 3 to 20 carbon
atoms for R.sup.6', R.sup.7' and R.sup.8' may be either a
polycyclic group or a monocyclic group, and examples thereof
include groups in which one hydrogen atom has been removed from a
monocycloalkane, and groups in which one hydrogen atom has been
removed from a polycycloalkane (e.g., a bicycloalkane, a
tricycloalkane or a tetracycloalkane). More specific examples
include groups in which one hydrogen atom has been removed from a
monocycloalkane such as cyclopentane, cyclohexane, cycloheptane or
cyclooctane; and groups in which one hydrogen atoms has been
removed from a polycycloalkane such as adamantane, norbornane,
isobornane, tricyclodecane or tetracyclododecane.
[0364] The cyclic, saturated hydrocarbon group may have a
substituent. For example, part of the carbon atoms constituting the
ring within the cyclic alkyl group may be substituted with a hetero
atom, or a hydrogen atom bonded to the ring within the cyclic alkyl
group may be substituted with a substituent.
[0365] In the former example, a heterocycloalkane in which part of
the carbon atoms constituting the ring within the aforementioned
monocycloalkane or polycycloalkane has been substituted with a
hetero atom such as an oxygen atom, a sulfur atom or a nitrogen
atom, and one or more hydrogen atoms have been removed therefrom,
can be used. Further, the ring may contain an ester bond
(--C(.dbd.O)--O--). More specific examples include a
lactone-containing monocyclic group, such as a group in which one
hydrogen atom has been removed from .gamma.-butyrolactone; and a
lactone-containing polycyclic group, such as a group in which one
hydrogen atom has been removed from a bicycloalkane, tricycloalkane
or tetracycloalkane containing a lactone ring.
[0366] In the latter example, as the substituent, the same
substituent groups as those for the aforementioned linear or
branched alkyl group, or an alkyl group of 1 to 5 carbon atoms can
be used.
[0367] Alternatively, R.sup.6', R.sup.7' and R.sup.8' may be a
combination of a linear or branched alkyl group and a cyclic
group.
[0368] Examples of the combination of a linear or branched alkyl
group with a cyclic alkyl group include groups in which a cyclic
alkyl group as a substituent is bonded to a linear or branched
alkyl group, and groups in which a linear or branched alkyl group
as a substituent is bonded to a cyclic alkyl group.
[0369] Examples of the linear aliphatic unsaturated hydrocarbon
group for R.sup.6', R.sup.7' and R.sup.8' include a vinyl group, a
propenyl group (an allyl group) and a butynyl group.
[0370] Examples of the branched aliphatic unsaturated hydrocarbon
group for R.sup.6', R.sup.7' and R.sup.8' include a
1-methylpropenyl group and a 2-methylpropenyl group.
[0371] The aforementioned linear or branched, aliphatic unsaturated
hydrocarbon group may have a substituent. Examples of substituents
include the same substituents as those which the aforementioned
linear or branched alkyl group may have.
[0372] Among the aforementioned examples, as R.sup.7' and R.sup.8',
in terms of improvement in lithography properties and shape of the
resist pattern, a linear or branched, saturated hydrocarbon group
of 1 to 15 carbon atoms or a cyclic saturated hydrocarbon group of
3 to 20 carbon atoms is preferable.
[0373] Examples of the alkyl group for R.sup.1'' to R.sup.3''
include linear, branched or cyclic alkyl groups of 1 to 10 carbon
atoms. Among these, alkyl groups of 1 to 5 carbon atoms are
preferable as the resolution becomes excellent. Specific examples
thereof include a methyl group, an ethyl group, an n-propyl group,
an isopropyl group, an n-butyl group, an isobutyl group, an
n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl
group, a nonyl group, and a decyl group, and a methyl group is most
preferable because it is excellent in resolution and can be
synthesized at a low cost.
[0374] The alkyl group for R.sup.1'' to R.sup.3'' may have part or
all of the hydrogen atoms substituted with an alkoxy group, a
halogen atom, a hydroxy group, an oxo group (.dbd.O), an aryl
group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group,
C(.dbd.O)--O--R.sup.6', --O--C(.dbd.O)--R.sup.7' or --O--R.sup.8'.
As the alkoxy group, the halogen atom, the aryl group, the
alkoxyalkyloxy group, the alkoxycarbonylalkyloxy group,
--C(.dbd.O)--O--R.sup.6', --O--C(.dbd.O)--R.sup.7' and
--O--R.sup.8', the same substituents as those described above for
substituting aryl group for R.sup.1'' to R.sup.3'' can be used.
[0375] The alkenyl group for R.sup.1'' to R.sup.3'' preferably has
2 to 10 carbon atoms, more preferably 2 to 5, and still more
preferably 2 to 4. Specific examples thereof include a vinyl group,
a propenyl group (an allyl group), a butynyl group, a
1-methylpropenyl group and a 2-methylpropenyl group.
[0376] When two of R.sup.1'' to R.sup.3'' are bonded to each other
to form a ring with the sulfur atom, it is preferable that the two
of R.sup.1'' to R.sup.3'' form a 3 to 10-membered ring including
the sulfur atom, and it is particularly desirable that the two of
R.sup.1'' to R.sup.3'' form a 5 to 7-membered ring including the
sulfur atom.
[0377] Preferable examples of the cation moiety of the compound
represented by the aforementioned formula (b-c1) are shown
below.
##STR00024## ##STR00025## ##STR00026## ##STR00027## ##STR00028##
##STR00029## ##STR00030## ##STR00031## ##STR00032## ##STR00033##
##STR00034##
[0378] In the formulas, g1, g2 and g3 represent recurring numbers,
wherein g1 is an integer of 1 to 5, g2 is an integer of 0 to 20,
and g3 is an integer of 0 to 20.
##STR00035## ##STR00036##
[0379] In formula (ca-1-47), R.sup.d represents a substituent.
Examples of the substituent include those described above in the
explanation of the aforementioned substituted aryl group (an alkyl
group, an alkoxy group, an alkoxyalkyloxy group, an
alkoxycarbonylalkyloxy group, a halogen atom, a hydroxy group, an
oxo group (.dbd.O), an aryl group, --C(.dbd.O)--O--R.sup.6',
--O--C(.dbd.O)--R.sup.7' and --O--R.sup.8'.
[0380] In formula (b-c2), R.sup.5'' and R.sup.6'' each
independently represents an aryl group which may have a
substituent, an alkyl group which may have a substituent or an
alkenyl group which may have a substituent.
[0381] As the aryl group for R.sup.5'' and R.sup.6'', the same aryl
groups as those described above for R.sup.1'' to R.sup.3'' can be
used.
[0382] As the alkyl group for R.sup.5'' and R.sup.6'', the same
alkyl groups as those described above for R.sup.1'' to R.sup.3''
can be used.
[0383] As the alkenyl group for R.sup.5'' to R.sup.6'', the same
alkenyl groups as those described above for R.sup.1'' to R.sup.3''
can be used.
[0384] Specific examples of the cation moiety of the compound
represented by general formula (b-c2) include diphenyliodonium and
bis(4-tert-butylphenyl)iodonium.
[0385] In the present description, an oximesulfonate acid generator
is a compound having at least one group represented by general
formula (B-1) shown below, and has a feature of generating acid by
irradiation of radial rays (exposure). Such oximesulfonate acid
generators may be selected appropriately from the various
oximesulfonate acid generators widely used within conventional
chemically amplified resist compositions.
##STR00037##
[0386] In the formula (B-1), R.sup.31 and R.sup.32 each
independently represents an organic group.
[0387] The organic group for R.sup.31 and R.sup.32 refers to a
group containing a carbon atom, and may include atoms other than
carbon atoms (e.g., a hydrogen atom, an oxygen atom, a nitrogen
atom, a sulfur atom, a halogen atom (such as a fluorine atom and a
chlorine atom) and the like).
[0388] As the organic group for R.sup.31, a linear, branched, or
cyclic alkyl group or aryl group is preferable. The alkyl group or
the aryl group may have a substituent. The substituent is not
particularly limited, and examples thereof include a fluorine atom
and a linear, branched, or cyclic alkyl group having 1 to 6 carbon
atoms. The alkyl group or the aryl group "has a substituent" means
that part or all of the hydrogen atoms of the alkyl group or the
aryl group is substituted with a substituent.
[0389] The alkyl group preferably has 1 to 20 carbon atoms, more
preferably 1 to 10 carbon atoms, still more preferably 1 to 8
carbon atoms, particularly preferably 1 to 6 carbon atoms, and most
preferably 1 to 4 carbon atoms. As the alkyl group, a partially or
completely halogenated alkyl group (hereinafter, sometimes referred
to as a "halogenated alkyl group") is particularly desirable. The
"partially halogenated alkyl group" refers to an alkyl group in
which part of the hydrogen atoms are substituted with halogen atoms
and the "completely halogenated alkyl group" refers to an alkyl
group in which all of the hydrogen atoms are substituted with
halogen atoms. Examples of halogen atoms include fluorine atoms,
chlorine atoms, bromine atoms and iodine atoms, and fluorine atoms
are particularly desirable. In other words, the halogenated alkyl
group is preferably a fluorinated alkyl group.
[0390] The aryl group preferably has 4 to 20 carbon atoms, more
preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon
atoms. As the aryl group, partially or completely halogenated aryl
group is particularly desirable. The "partially halogenated aryl
group" refers to an aryl group in which some of the hydrogen atoms
are substituted with halogen atoms and the "completely halogenated
aryl group" refers to an aryl group in which all of hydrogen atoms
are substituted with halogen atoms.
[0391] As R.sup.31, an alkyl group of 1 to 4 carbon atoms which has
no substituent or a fluorinated alkyl group of 1 to 4 carbon atoms
is particularly desirable.
[0392] As the organic group for R.sup.32, a linear, branched, or
cyclic alkyl group, an aryl group, or a cyano group is preferable.
As the alkyl group or the aryl group for R.sup.32, the same alkyl
groups or aryl groups as those described above for R.sup.31 can be
used.
[0393] As R.sup.32, a cyano group, an alkyl group of 1 to 8 carbon
atoms having no substituent or a fluorinated alkyl group of 1 to 8
carbon atoms is particularly desirable.
[0394] Preferable examples of the oxime sulfonate-based acid
generator include compounds represented by general formula (B-2) or
(B-3) shown below.
##STR00038##
[0395] In the formula (B-2), R.sup.33 represents a cyano group, an
alkyl group having no substituent or a halogenated alkyl group;
R.sup.34 represents a group containing an aryl group; an alkyl
group or a halogenated alkyl group for R.sup.34 and R.sup.35 may be
mutually bonded to form a ring; and R.sup.35 represents an alkyl
group having no substituent or a halogenated alkyl group.
##STR00039##
[0396] In the formula (B-3), R.sup.36 represents a cyano group, an
alkyl group having no substituent or a halogenated alkyl group;
R.sup.37 represents a divalent or trivalent aromatic hydrocarbon
group; R.sup.38 represents an alkyl group having no substituent or
a halogenated alkyl group; and p'' represents 2 or 3.
[0397] In general formula (B-2), the alkyl group having no
substituent or the halogenated alkyl group for R.sup.33 preferably
has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and
most preferably 1 to 6 carbon atoms.
[0398] As R.sup.33, a halogenated alkyl group is preferable, and a
fluorinated alkyl group is more preferable.
[0399] The fluorinated alkyl group for R.sup.33 preferably has 50%
or more of the hydrogen atoms thereof fluorinated, more preferably
70% or more, and most preferably 90% or more.
[0400] Examples of the group containing an aryl group for R.sup.34
include groups in which one hydrogen atom has been removed from an
aromatic hydrocarbon ring, such as a phenyl group, a biphenyl
group, a fluorenyl group, a naphthyl group, an anthryl group, and a
phenantryl group, and heteroaryl groups in which some of the carbon
atoms constituting the ring(s) of these groups are substituted with
hetero atoms such as an oxygen atom, a sulfur atom, and a nitrogen
atom. Of these, a fluorenyl group is preferable.
[0401] The aryl group for R.sup.34 may have a substituent such as
an alkyl group of 1 to 10 carbon atoms, a halogenated alkyl group,
or an alkoxy group. The alkyl group and halogenated alkyl group as
the substituent preferably has 1 to 8 carbon atoms, and more
preferably 1 to 4 carbon atoms. Further, the halogenated alkyl
group is preferably a fluorinated alkyl group.
[0402] The alkyl group having no substituent or the halogenated
alkyl group for R.sup.35 preferably has 1 to 10 carbon atoms, more
preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon
atoms.
[0403] As R.sup.35, a halogenated alkyl group is preferable, and a
fluorinated alkyl group is more preferable.
[0404] In terms of enhancing the strength of the acid generated,
the fluorinated alkyl group for R.sup.35 preferably has 50% or more
of the hydrogen atoms fluorinated, more preferably 70% or more,
still more preferably 90% or more. A completely fluorinated alkyl
group in which 100% of the hydrogen atoms are substituted with
fluorine atoms is particularly desirable.
[0405] In general formula (B-3), as the alkyl group having no
substituent and the halogenated alkyl group for R.sup.36, the same
alkyl group having no substituent and the halogenated alkyl group
described above for R.sup.33 can be used.
[0406] Examples of the divalent or trivalent aromatic hydrocarbon
group for R.sup.37 include groups in which one or two hydrogen
atoms have been removed from the aryl group for R.sup.34.
[0407] As the alkyl group having no substituent or the halogenated
alkyl group for R.sup.38, the same one as the alkyl group having no
substituent or the halogenated alkyl group for R.sup.35 can be
used.
[0408] p'' is preferably 2.
[0409] Specific examples of suitable oxime sulfonate acid
generators include .alpha.-(p-toluenesulfonyloxyimino)-benzyl
cyanide, .alpha.-(p-chlorobenzenesulfonyloxyimino)-benzyl cyanide,
.alpha.-(4-nitrobenzenesulfonyloxyimino)-benzyl cyanide,
.alpha.-(4-nitro-2-trifluoromethylbenzenesulfonyloxyimino)-benzyl
cyanide, .alpha.-(benzenesulfonyloxyimino)-4-chlorobenzyl cyanide,
.alpha.-(benzenesulfonyloxyimino)-2,4-dichlorobenzyl cyanide,
.alpha.-(benzenesulfonyloxyimino)-2,6-dichlorobenzyl cyanide,
.alpha.-(benzenesulfonyloxyimino)-4-methoxybenzyl cyanide,
.alpha.-(2-chlorobenzenesulfonyloxyimino)-4-methoxybenzyl cyanide,
.alpha.-(benzenesulfonyloxyimino)-thien-2-yl acetonitrile,
.alpha.-(4-dodecylbenzenesulfonyloxyimino)benzyl cyanide,
.alpha.-[(p-toluenesulfonyloxyimino)-4-methoxyphenyl]acetonitrile,
.alpha.-[(dodecylbenzenesulfonyloxyimino)-4-methoxyphenyl]acetonitrile,
.alpha.-(tosyloxyimino)-4-thienyl cyanide,
.alpha.-(methylsulfonyloxyimino)-1-cyclopentenyl acetonitrile,
.alpha.-(methylsulfonyloxyimino)-1-cyclohexenyl acetonitrile,
.alpha.-(methylsulfonyloxyimino)-1-cycloheptenyl acetonitrile,
.alpha.-(methylsulfonyloxyimino)-1-cyclooctenyl acetonitrile,
.alpha.-(trifluoromethylsulfonyloxyimino)-1-cyclopentenyl
acetonitrile, .alpha.-(trifluoromethylsulfonyloxyimino)-cyclohexyl
acetonitrile, .alpha.-(ethylsulfonyloxyimino)-ethyl acetonitrile,
.alpha.-(propyl sulfonyloxyimino)-propyl acetonitrile,
.alpha.-(cyclohexylsulfonyloxyimino)-cyclopentyl acetonitrile,
.alpha.-(cyclohexylsulfonyloxyimino)-cyclohexyl acetonitrile,
.alpha.-(cyclohexylsulfonyloxyimino)-1-cyclopentenyl acetonitrile,
.alpha.-(ethylsulfonyloxyimino)-1-cyclopentenyl acetonitrile,
.alpha.-(isopropylsulfonyloxyimino)-1-cyclopentenyl acetonitrile,
.alpha.-(n-butyl sulfonyloxyimino)-1-cyclopentenyl acetonitrile,
.alpha.-(ethylsulfonyloxyimino)-1-cyclohexenyl acetonitrile,
.alpha.-(isopropylsulfonyloxyimino)-1-cyclohexenyl acetonitrile,
.alpha.-(n-butylsulfonyloxyimino)-1-cyclohexenyl acetonitrile,
.alpha.-(methylsulfonyloxyimino)-phenyl acetonitrile,
(methylsulfonyloxyimino)-p-methoxyphenyl acetonitrile,
.alpha.-(trifluoromethylsulfonyloxyimino)-phenyl acetonitrile,
.alpha.-(trifluoromethylsulfonyloxyimino)-p-methoxyphenyl
acetonitrile, .alpha.-(ethylsulfonyloxyimino)-p-methoxyphenyl
acetonitrile, .alpha.-(propylsulfonyloxyimino)-p-methylphenyl
acetonitrile, and .alpha.-(methylsulfonyloxyimino)-p-bromophenyl
acetonitrile.
[0410] Further, oxime sulfonate acid generators disclosed in
Japanese Unexamined Patent Application, First Publication No. Hei
9-208554 (Chemical Formulas 18 and 19 shown in paragraphs [0012] to
[0014]) and oxime sulfonate acid generators disclosed in WO
2004/074242A2 (Examples 1 to 40 described at pages 65 to 85) may be
preferably used.
[0411] Furthermore, as preferable examples, the following can be
used.
##STR00040##
[0412] Of the aforementioned diazomethane-based acid generators,
specific examples of suitable bisalkyl or bisaryl sulfonyl
diazomethanes include bis(isopropylsulfonyl)diazomethane,
bis(p-toluenesulfonyl)diazomethane,
bis(1,1-dimethylethylsulfonyl)diazomethane,
bis(cyclohexylsulfonyl)diazomethane, and
bis(2,4-dimethylphenylsulfonyl)diazomethane.
[0413] Further, diazomethane-based acid generators disclosed in
Japanese Unexamined Patent Application, First Publication No. Hei
11-035551, Japanese Unexamined Patent Application, First
Publication No. Hei 11-035552 and Japanese Unexamined Patent
Application, First Publication No. Hei 11-035573 may be preferably
used.
[0414] Furthermore, as poly(bis-sulfonyl)diazomethanes, those
disclosed in Japanese Unexamined Patent Application, First
Publication No. Hei 11-322707, including
1,3-bis(phenylsulfonyldiazomethylsulfonyl)propane,
1,4-bis(phenylsulfonyldiazomethylsulfonyl)butane,
1,6-bis(phenylsulfonyldiazomethylsulfonyl)hexane,
1,10-bis(phenylsulfonyldiazomethylsulfonyl)decane,
1,2-bis(cyclohexylsulfonyldiazomethylsulfonyl)ethane,
1,3-bis(cyclohexylsulfonyldiazomethylsulfonyl)propane,
1,6-bis(cyclohexylsulfonyldiazomethylsulfonyl)hexane, and
1,10-bis(cyclohexylsulfonyldiazomethylsulfonyl)decane, may be
mentioned.
[0415] As the component (B), one type of these acid generators may
be used alone, or two or more types may be used in combination.
[0416] In the case where the undercoat agent contains the component
(B), when the component (B) is a thermal acid generator, the amount
of the component (B) relative to 100 parts by weight of the
component (A) is preferably within a range from 0.5 to 30 parts by
weight, more preferably from 1 to 20 parts by weight. When the
component (B) is a photoacid generator, the amount of the component
(B) is preferably within a range from 0.5 to 30 parts by weight,
more preferably from 1 to 20 parts by weight. When the amount of
the component (B) is within the above-mentioned range, the effect
of the present invention is satisfactorily exerted, and when the
amount of the component (B) is at least as large as the lower limit
of the above-mentioned range, the amount of the component (A) in
the undercoat agent does not decrease.
[0417] When the undercoat agent contains the component (B), the
amount of the component (B) based on the total of the component (G)
and the component (B) is preferably 50% by weight or less, and more
preferably 20% by weight or more.
[0418] If desired, other miscible additives can also be added to
the undercoat agent of the present invention. Examples of such
miscible additives include additive resins for improving the
performance of the layer composed of the undercoat agent,
surfactants for improving the applicability, dissolution
inhibitors, plasticizers, stabilizers, colorants, halation
prevention agents, dyes, sensitizers, base amplifiers and basic
compound.
[0419] [Organic Solvent; Component (S)]
[0420] The undercoat agent of the present invention can be prepared
by dissolving the materials for the undercoat agent in an organic
solvent (hereafter, referred to as "component (S)").
[0421] The component (S) may be any organic solvent which can
dissolve the respective components to give a uniform solution, and
one or more kinds of any organic solvent can be appropriately
selected from those which have been conventionally known as
solvents for a film composition containing a resin as a main
component.
[0422] Examples thereof include lactones such as
.gamma.-butyrolactone; ketones such as acetone, methyl ethyl
ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl
ketone, and 2-heptanone; polyhydric alcohols, such as ethylene
glycol, diethylene glycol, propylene glycol and dipropylene glycol;
compounds having an ester bond, such as ethylene glycol
monoacetate, diethylene glycol monoacetate, propylene glycol
monoacetate, and dipropylene glycol monoacetate; polyhydric alcohol
derivatives including compounds having an ether bond, such as a
monoalkylether (e.g., monomethylether, monoethylether,
monopropylether or monobutylether) or monophenylether of any of
these polyhydric alcohols or compounds having an ester bond (among
these, propylene glycol monomethyl ether acetate (PGMEA) and
propylene glycol monomethyl ether (PGME) are preferable); cyclic
ethers such as dioxane; esters such as methyl lactate, ethyl
lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl
pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl
ethoxypropionate; and aromatic organic solvents such as anisole,
ethylbenzylether, cresylmethylether, diphenylether, dibenzylether,
phenetole, butylphenylether, ethylbenzene, diethylbenzene,
pentylbenzene, isopropylbenzene, toluene, xylene, cymene and
mesitylene.
[0423] These solvents can be used individually, or in combination
as a mixed solvent.
[0424] Among these, propylene glycol monomethyl ether acetate
(PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone
and ethyl lactate (EL) are preferable.
[0425] Further, among the mixed solvents, a mixed solvent obtained
by mixing PGMEA with a polar solvent is preferable. The mixing
ratio (weight ratio) of the mixed solvent can be appropriately
determined, taking into consideration the compatibility of the
PGMEA with the polar solvent, but is preferably in the range of 1:9
to 9:1, more preferably from 2:8 to 8:2. For example, when EL is
mixed as the polar solvent, the PGMEA:EL weight ratio is preferably
from 1:9 to 9:1, and more preferably from 2:8 to 8:2.
Alternatively, when PGME is mixed as the polar solvent, the
PGMEA:PGME is preferably from 1:9 to 9:1, more preferably from 2:8
to 8:2, and still more preferably 3:7 to 7:3. Alternatively, when
PGME and cyclohexanone is mixed as the polar solvent, the
PGMEA:(PGME+cyclohexanone) weight ratio is preferably from 1:9 to
9:1, more preferably from 2:8 to 8:2, and still more preferably 3:7
to 7:3.
[0426] Further, as the component (S), a mixed solvent of
.gamma.-butyrolactone with PGMEA, EL or the aforementioned mixed
solvent of PGMEA with a polar solvent, is also preferable. The
mixing ratio (former:latter) of such a mixed solvent is preferably
from 70:30 to 95:5.
[0427] The amount of the component (S) is not particularly limited,
and is appropriately adjusted to a concentration which enables
coating of a coating solution to a substrate, depending on the
thickness of the coating film. In general, the organic solvent is
used in an amount such that the solid content of the undercoat
agent becomes within the range from 1 to 20% by weight, and
preferably from 2 to 15% by weight.
[0428] <<Method of Forming Pattern of Layer Containing Block
Copolymer>>
[0429] The second aspect of the present invention is a method of
forming a pattern of a layer containing a block copolymer,
including: a step (1) in which the aforementioned undercoat agent
of the first aspect of the present invention is applied to a
substrate to form a layer composed of the undercoat agent;
[0430] a step (2) in which a layer containing a block copolymer
having a plurality of blocks bonded is formed on a surface of the
layer composed of the undercoat agent, followed by a phase
separation of the layer containing the block copolymer; and
[0431] a step (3) in which a phase composed of at least one block
of the plurality of blocks constituting the block copolymer is
selectively removed (hereafter, simply referred to as "method of
forming a pattern").
[0432] Hereinbelow, the method of forming a pattern according to
the present invention will be specifically described, with
reference to the drawings. However, the present invention is not
limited to these embodiments.
[0433] FIG. 1 shows an example of one embodiment of the method of
forming a pattern according to the present invention.
[0434] In this embodiment, the undercoat agent of the first aspect
is applied to a substrate 1 to form a layer 2 composed of the
undercoat agent (step (1)). Next, a layer 3 containing a block
copolymer having a plurality of blocks bonded is formed, for
example, by applying the block copolymer on a surface of the layer
2 composed of the undercoat agent, followed by a phase separation
of the layer 3 containing the block copolymer (step (2)). Finally,
a phase 3a of at least one block of the plurality of blocks
constituting the block copolymer is selectively removed from the
layer 3 containing the block copolymer, thereby forming a pattern
(step (3)).
[0435] [Step (1)]
[0436] There are no particular limitations on the substrate 1,
provided that the substrate does not dissolve or mix when the
undercoat agent or the block copolymer is applied, and the types of
conventional materials used as the substrates for electronic
components and the like can be used.
[0437] Specific examples of the substrate 1 include metal
substrates formed from metal such as silicon wafer, gold, copper,
chromium, iron or aluminum or the like, metal oxide substrates
formed by oxidation of the above metals, glass substrates, and
polymer films (such as polyethylene, polyethylene terephthalate,
polyimide and benzocyclobutene). In those cases where an undercoat
agent having a trialkoxysilyl group as the substrate interaction
group is used in the step (2), as a substrate 1, a silicon wafer is
preferably used.
[0438] Further, the size and the shape of the substrate is not
particularly limited. The substrate 1 does not necessarily need to
have a smooth surface, and a substrate made of various materials
and having various shapes can be appropriately selected for use.
For example, a multitude of shapes can be used, such as a substrate
having a curved surface, a plate having an uneven surface, and a
thin sheet.
[0439] Further, as the substrate 1, any one of the above-mentioned
substrates provided with an inorganic and/or organic film on the
surface thereof may be used, and a substrate provided with an
organic film is preferable. As the inorganic film, an inorganic
anti-reflection film (inorganic BARC) can be used. As the organic
film, an organic anti-reflection film (organic BARC) can be
used.
[0440] An inorganic film can be formed, for example, by coating an
in organic anti-reflection film composition such as a silicon-based
material (e.g., SOG film material, SiON film material and the like)
on a substrate, followed by baking. The undercoat agent of the
present invention is preferably used for an SOG substrate coated by
an SOG film material and an SiON substrate coated by an SiON film
material.
[0441] An organic film can be formed, for example, by dissolving a
resin component and the like for forming the film in an organic
solvent to obtain an organic film-forming material, coating the
organic film-forming material on a substrate using a spinner or the
like, and baking under heating conditions preferably in the range
of 200 to 300.degree. C. for 30 to 300 seconds, more preferably for
60 to 180 seconds. The organic film-forming material does not need
to have susceptibility to light or electron beam like a resist
film, and the organic film-forming material may or may not have
such susceptibility. More specifically, a resist or a resin
generally used in the production of a semiconductor device or a
liquid crystal display device can be used.
[0442] Further, it is preferable that the organic film-forming
material can be subjected to etching, particularly dry etching, so
that, by etching the organic film using a pattern composed of a
block copolymer, the pattern can be transferred to the organic
film, and an organic film pattern can be formed. It is particularly
desirable to use an organic film-forming material which can be
subjected to oxygen plasma etching or the like. As such an organic
film-forming material, a material conventionally used for forming
an organic film such as an organic BARC can be used. Examples of
such an organic film-forming material include the ARC series
manufactured by Brewer Science Ltd., the AR series manufactured by
Rohm and Haas Company, and the SWK series manufactured by Tokyo
Ohka Kogyo Co., Ltd.
[0443] The undercoat agent of the first aspect of the present
invention contains a substrate interaction group, and therefore,
even when a substrate 1 on which an organic film as described above
has been formed, the layer 2 composed of the undercoat agent can
satisfactorily interact with the substrate 1, and hence, the layer
2 composed of the undercoat agent becomes a film having excellent
strength and adhesion property.
[0444] Further the surface of the substrate 1 may be washed in
advance. By washing the surface of the substrate, the
neutralization reaction treatment in a later step may be
satisfactorily performed.
[0445] As the washing treatment, a conventional method may be used,
and examples thereof include an oxygen plasma treatment, an ozone
oxidation treatment, an acid alkali treatment, and a chemical
modification treatment.
[0446] The method of applying the undercoat agent to the substrate
1 to form a layer 2 composed of the undercoat agent is not
particularly limited, and the layer 2 can be formed by a
conventional method.
[0447] For example, the undercoat agent can be applied to the
substrate 1 by a conventional method using a spinner or the like to
form a coating film on the substrate 1, followed by drying, thereby
forming a layer 2 composed of the undercoat agent.
[0448] Drying the coating film can be conducted so as to volatilize
the organic solvent (component (S)) contained in the undercoat
agent, and examples of the drying method include a method of
conducting baking.
[0449] The baking temperature is preferably 80 to 300.degree. C.,
more preferably 100 to 270.degree. C., and still more preferably
120 to 250.degree. C. The baking time is preferably 30 to 500
seconds, and more preferably 60 to 240 seconds.
[0450] In those cases where the undercoat agent includes the
aforementioned component (G) or an acid generator that generates
acid upon heating as the aforementioned component (B), a favorable
layer 2 composed of the undercoat agent can be obtained under the
action of the acidic compound or the acid even if the
aforementioned baking time is shortened. When the component (B) in
the undercoat agent is a photo acid generator, light or an electron
beam or the like may be irradiated onto the layer before or after
baking to generate the acid. Irradiation can be conducted by a
normal method.
[0451] When a layer 2 composed of the undercoat agent is formed on
the surface of a substrate 1, the surface of the substrate 1 is
neutralized. As a result, it becomes possible to prevent only
phases of specific block within the layer 3 (which is composed of a
block copolymer and is formed on the layer 2) to come into contact
with the surface of the substrate.
[0452] As a result, by a phase separation of the layer 3 containing
the block copolymer, a cylinder structure, dot structure or gyroid
structure which is freely oriented on the surface of the substrate
can be formed.
[0453] Furthermore, after the step (1) and before the step (2)
(prior to forming a layer 3 composed of the block copolymer), a
guide pattern having a predetermined pattern may be formed in
advance on the layer 2 composed of the undercoat agent. As a
result, it becomes possible to control the arrangement of the phase
separation structure, depending on the shape and surface properties
of the guide pattern. For example, in the case of a block copolymer
where a random fingerprint-patterned phase separation structure is
formed without using a guide pattern, by introducing a trench
pattern of a resist film on the surface of the substrate, a phase
separation structure arranged along the trench can be obtained. The
guide pattern can be introduced in accordance with the
above-described principle. Further, when the surface of the guide
pattern has affinity for any of the polymers constituting the block
copolymer, a phase separation structure having a lamellar structure
or a cylinder structure arranged in the perpendicular direction of
the surface of the substrate can be more reliably formed.
[0454] More specifically, for example, a resist composition is
applied to the surface of the substrate using a spinner or the
like, and a prebake (post applied bake (PAB)) is conducted under
temperature conditions of 80 to 150.degree. C. for 40 to 120
seconds, preferably 60 to 90 seconds. Then, for example, using an
ArF exposure apparatus or the like, the resist film is selectively
exposed to an ArF excimer laser through a desired mask pattern,
followed by post exposure bake (PEB) under temperature conditions
of 80 to 150.degree. C. for 40 to 120 seconds, preferably 60 to 90
seconds. Subsequently, developing is conducted using an alkali
developing solution such as a 0.1 to 10% by weight aqueous solution
of tetramethylammonium hydroxide (TMAH), preferably followed by
rinsing with pure water, and drying. If desired, bake treatment
(post bake) can be conducted following the developing. In this
manner, a guide pattern that is faithful to the mask pattern can be
formed.
[0455] The height of the guide pattern from the surface of the
substrate (or the surface of the neutralization film) is preferably
at least as large as the thickness of the layer containing the
block copolymer which is formed on the surface of the substrate.
The height of the guide pattern from the surface of the substrate
(or the surface of the neutralization film) can be appropriately
adjusted by the film thickness of the resist film formed by
applying the resist composition for forming a guide pattern.
[0456] The resist composition for forming the guide pattern can be
appropriately selected from resist compositions or a modified
product thereof typically used for forming a resist pattern which
have affinity for any of the polymers constituting the block
copolymer. With respect to the resist composition, a positive
resist composition which forms a positive pattern by dissolving and
removing the exposed portions, or a negative resist composition
which forms a negative pattern by dissolving and removing the
unexposed portions can be used, and a negative resist composition
is preferable. As the negative resist composition, for example, a
resist composition containing an acid generator component and a
base component which exhibits decreased solubility in a developing
solution containing an organic solvent by the action of acid, and
the base component is a resin component which contains a structural
unit that is decomposed by the action of acid to increase
polarity.
[0457] When a solution of the block copolymer is cast onto the
surface of the substrate having a guide pattern formed, and a heat
treatment is conducted to cause a phase separation. Therefore, the
resist composition for forming a guide pattern is preferably
capable of forming a resist film which exhibits solvent resistance
and heat resistance.
[0458] [Step (2)]
[0459] The method for forming a layer 3 containing a block
copolymer having a plurality of blocks bonded, on the layer 2
composed of the undercoat agent is not particularly limited, and
for example, a method in which a composition containing a block
copolymer is applied onto the layer 2 composed of the undercoat
agent can be used. As the method of applying, the same method as
those described above for applying the undercoat agent can be
used.
[0460] In the present invention, the lower limit of the thickness
of the layer 3 containing the block copolymer is not particularly
limited, as long as it is sufficient for causing phase separation.
In consideration of the size of periodic structure of phase
separation structure to be formed and the uniformity of the nano
structure, the thickness of the layer is preferably 5 nm or more,
and more preferably 10 nm or more.
[0461] (Composition Containing Block Copolymer)
[0462] Block Copolymer
[0463] In the present invention, a block copolymer is a polymeric
material in which plurality of constituent parts (i.e., block) in
which only the structural units of the same type have been bonded,
are bonded. As the blocks constituting the block copolymer, 2 types
of blocks may be used, or 3 or more types of blocks may be used. In
the present invention, the plurality of blocks constituting the
block copolymer are not particularly limited, as long as they are
combinations capable of causing phase separation. However, it is
preferable to use a combination of blocks which are mutually
incompatible. Further, it is preferable to use a combination in
which a phase of at least one block amongst the plurality of blocks
constituting the block copolymer can be easily subjected to
selective removal as compared to the phases of other blocks.
[0464] Examples of the block copolymer includes: [0465] a block
copolymer having a block composed of a structural unit derived from
styrene or a derivative thereof bonded to a block composed of a
structural unit derived from a (.alpha.-substituted)acrylate ester;
[0466] a block copolymer having a block composed of a structural
unit derived from styrene or a derivative thereof bonded to a block
composed of a structural unit derived from siloxane or derivative
thereof; and [0467] a block copolymer having a block composed of a
structural unit derived from alkyleneoxyde bonded to a block
composed of a structural unit derived from a
(.alpha.-substituted)acryl ate ester.
[0468] The structural unit derived from styrene or a derivative
thereof and the structural unit derived from a
(.alpha.-substituted)acrylate ester are the same as defined
above.
[0469] Examples of the siloxane derivative include
dimethylsiloxane, diethylsiloxane, diphenylsiloxane, and
methylphenylsiloxane.
[0470] Examples of the alkylene oxide include ethylene oxide,
propylene oxide, isopropylene oxide and butylene oxide.
[0471] Among these as a block copolymer, it is preferable to use a
block copolymer having a block composed of a structural unit
derived from styrene or a derivative thereof bonded to a block
composed of a structural unit derived from a (meth)acrylate
ester.
[0472] Specific examples thereof include a polystyrene-polymethyl
methacrylate (PS-PMMA) block copolymer, a polystyrene-polyethyl
methacrylate block copolymer, a polystyrene-(poly-t-butyl
methacrylate) block copolymer, a polystyrene-polymethacrylic acid
block copolymer, a polystyrene-polymethyl acrylate block copolymer,
a polystyrene-polyethyl acrylate block copolymer, a
polystyrene-(poly-t-butyl acrylate) block copolymer, and a
polystyrene-polyacrylic acid block copolymer. Among these, PS-PMMA
block copolymer is particularly preferable.
[0473] The weight average molecular weight (Mw) (the polystyrene
equivalent value determined by gel permeation chromatography) of
each polymer constituting the block copolymer is not particularly
limited as long as it is large enough to cause phase separation.
The weight average molecular weight is preferably 5,000 to 500,000,
more preferably 5,000 to 400,000, and still more preferably 5,000
to 300,000.
[0474] The polydispersity (Mw/Mn) of the block copolymer is
preferably 1.0 to 3.0, more preferably 1.0 to 1.5, and still more
preferably 1.0 to 1.2. Here, Mn is the number average molecular
weight.
[0475] If desired, other miscible additives can also be added to
the composition containing a block copolymer. Examples of such
miscible additives include additive resins for improving the
performance of the layer composed of the undercoat agent,
surfactants for improving the applicability, dissolution
inhibitors, plasticizers, stabilizers, colorants, halation
prevention agents, dyes, sensitizers, base amplifiers and basic
compound.
[0476] Organic Solvent
[0477] The composition containing a block copolymer can be prepared
by dissolving the aforementioned block copolymer in an organic
solvent. Examples of organic solvents that may be used include the
same solvents as those mentioned above for the component (S) used
as the organic solvent for the undercoat agent.
[0478] There are no particular limitations on the amount used of
the organic solvent in the composition containing the block
copolymer, which may be adjusted appropriately to produce a
concentration that enables application of the solution in
accordance with the desired thickness of the formed film. In
general, the organic solvent is used in an amount that yields a
solid content of the block copolymer that is within a range from
0.2 to 70% by weight, and preferably from 0.2 to 50% by weight.
[0479] With respect to the phase separation of the layer 3
containing the block copolymer, the substrate 1 on which the layer
3 containing the block copolymer and the layer 2 composed of the
undercoat agent have been formed, is subjected to a heat treatment,
and a phase separation structure in which at least a part of the
surface of the substrate is exposed is formed by a selective
removal of the block copolymer in a later step. The heat treatment
is preferably conducted at a temperature at least as high as the
glass transition temperature of the block copolymer used and lower
than the heat decomposition temperature. For example, when a
PS-PMMA (Mw: 40 k-20 k) is used as the block copolymer, it is
preferable to conduct a heat treatment at 180 to 270.degree. C. for
30 to 3,600 seconds.
[0480] Further, the heat treatment is preferably conducted in a low
reactive gas such as nitrogen.
[0481] [Step (3)]
[0482] In the step (3), a phase 3a of at least one block of the
plurality of blocks constituting the block copolymer is selectively
removed from the layer 3 containing the block copolymer, thereby
forming a pattern.
[0483] Hereafter, among the blocks constituting the block
copolymer, a block which is not selectively removed is referred to
as "block P.sub.A, and a block to be selectively removed is
referred to as "block P.sub.B. For example, after the phase
separation of a layer containing a PS-PMMA block copolymer, by
subjecting the layer to an oxygen plasma treatment or a hydrogen
plasma treatment, the phase of PMMA is selectively removed. In such
a case, PS is the block P.sub.A, and PMMA is the block P.sub.B.
[0484] Subsequently, after the formation of the phase separation
structure, at least a portion of the phase of block P.sub.B is
selectively removed from the layer containing the block copolymer
formed on the substrate (the molecular weight is decreased). By
selectively removing a portion of the block P.sub.B in advance, the
solubility in a developing solution can be enhanced. As a result,
the phase of the block P.sub.B can be more reliably removed by
selective removing than the phase of the block P.sub.A.
[0485] The selective removal treatment is not particularly limited,
as long as it is a treatment capable of decomposing and removing
the block P.sub.B without affecting the block P.sub.A. The
selective removal treatment can be appropriately selected from any
methods for removing a resin film, depending on the types of the
block P.sub.A and the block P.sub.B. Further, when a neutralization
film is formed on the surface of the substrate in advance, the
neutralization film is removed together with the phase of the block
P.sub.B. Examples of the removal treatment include an oxygen plasma
treatment, an ozone treatment, a UV irradiation treatment, a heat
decomposition treatment and a chemical decomposition treatment.
[0486] The substrate on which a pattern 3b has been formed by a
phase separation of the layer 3 containing the block copolymer in
the manner described above can be used without further
modification, or may be subjected to an additional heat treatment
to alter the shape of the polymer nanostructure on the substrate.
The heat treatment is preferably conducted at a temperature at
least as high as the glass transition temperature of the block
copolymer used and lower than the heat decomposition temperature.
Further, the heat treatment is preferably conducted in a low
reactive gas such as nitrogen.
EXAMPLES
[0487] As follows is a description of examples of the present
invention, although the scope of the present invention is in no way
limited by these examples.
[0488] [Production of Polymeric Compounds 1 to 9]
[0489] Polymeric compounds 1 to 9 were produced by a conventional
method using the following monomers (1) to (8) which derived the
structural units constituting each polymeric compound with a molar
ratio indicated in Table 1. The molecular weight (Mw) and the
molecular weight distribution (Mw/Mn) of the obtained polymeric
compounds are shown in Table 1.
##STR00041## ##STR00042##
TABLE-US-00001 TABLE 1 Polymeric Compound 1 2 3 4 5 6 7 8 9 Monomer
(1) 85 85 85 85 90 70 92 92 (2) 70 (3) 25 30 (4) 15 8 5 5 5 3 3 (5)
15 7 5 (6) 10 (7) 5 (8) 5 Mw 40000 10000 40000 100000 10000 20000
40000 57700 57700 Mw/Mn 1.9 1.6 1.8 1.7 1.8 1.7 1.7 1.7 1.7
Examples 1 to 16, Comparative Examples 1 and 2
[0490] First, 100 parts by weight of the polymeric compounds shown
in Table 2 were each mixed with 3 part by weight of an acidic
compound component or an acid generator that was added as required,
and 12,400 parts by weight of PGMEA, and the mixtures were
dissolved to prepare a series of undercoat agents.
[0491] The thus obtained undercoat agent of each example was
applied to a silicon wafer (Si substrate), a silicon wafer having
an SOG film formed on the surface thereof (product name: OCD-T11,
manufactured by Tokyo Ohka Kogyo Co., Ltd.), a silicon wafer having
a film composed of an organic anti-reflection film composition
(product name: ARC29A or ARC95, manufactured by Brewer Science
Ltd.) on the surface thereof, or a silicon wafer having an SiON
film on the surface thereof, using a spinner. In Examples 1 to 10
and Comparative Examples 1 and 2, a bake treatment was then
performed at 240.degree. C. for a period indicated in Table 2 to
form a layer composed of the undercoat agent having a thickness of
10 nm. Further, with respect to Examples 11 to 16, a bake treatment
was conducted for 60 seconds at a temperature indicated in Table
3.
[0492] Next, the layer was spun while a rinse was performed using
PGMEA for 15 seconds, and the thickness (nm) of the layer composed
of the undercoat agent was then measured using a UTFTA-200 (product
name, manufactured by Litho Tech Japan Corporation). In all
examples, the film thickness was no more than the detection limit
(1 nm). Further, as a result of observing the surface of the
substrate, in Examples 1 to 16, a thin film (a monomolecular film)
was formed from the undercoat agent.
[0493] Next, a solution (solvent: PGMEA) containing the block
copolymer shown in Table 2 or 3 and having a solid content of 1.8%
by weight was spin coated onto the substrate having the layer
composed of the undercoat agent formed thereon, thereby forming a
coating film having a thickness of 60 nm.
[0494] Subsequently, the substrate was heated at 240.degree. C. for
60 seconds while flowing nitrogen, thereby forming a
phase-separated structure. Thereafter, the substrate on which a
phase-separated structure had been formed, was subjected to an
oxygen plasma treatment (200 mL/minute, 40 Pa, 40.degree. C., 200
W, 20 seconds) using TCA-3822 (manufactured by Tokyo Ohka Kogyo
Co., Ltd.) to selectively remove the phase of PMMA. The surface of
the obtained substrate was observed using a scanning electron
microscope (SEM) SU8000 (manufactured by Hitachi High-Technologies
Corporation). A substrate on which a uniform pattern (vertical
lamella) was observed is evaluated as "A"; a substrate on which a
part where a uniform pattern (vertical lamella) had not been formed
was observed is evaluated as "B"; and a substrate on which a
uniform pattern (vertical lamella) was not observed is evaluated as
"C".
[0495] In Examples 11, 12, 15 and 16 in which an SiON substrate was
used, as well as vertical lamella pattern described above, cylinder
pattern was also evaluated. A substrate on which a uniform pattern
(cylinder) was observed is evaluated as "A"; a substrate on which a
part where a uniform pattern (cylinder) had not been formed was
observed is evaluated as "B"; and a substrate on which a uniform
pattern (cylinder) was not observed is evaluated as "C".
[0496] The results are shown in Tables 2 and 3.
TABLE-US-00002 TABLE 2 Acidic compound/ Polymeric Acid Bake Block
Si SOG ARC ARC compound generator (sec) copolymer substrate
substrate 29A 95 Example 1 (A)-1 300 (BP)-1 A A A A Example 2 (A)-1
(G)-1 60 (BP)-1 A A A A Example 3 (A)-1 (G)-2 60 (BP)-1 A A A A
Example 4 (A)-1 (B)-1 60 (BP)-1 A A A A Example 5 (A)-2 300 (BP)-1
A A A A Example 6 (A)-3 (G)-1 180 (BP)-1 A A A A Example 7 (A)-4
300 (BP)-2 A A A A Example 8 (A)-1 (B)-2 180 (BP)-1 A A A A Example
9 (A)-6 (G)-1 60 (BP)-1 A A A A Example 10 (A)-5 (G)-1 60 (BP)-1 A
A A A Comparative (A)-7 300 (BP)-1 C C C C Example 1 Comparative
(A)-7 (G)-1 60 (BP)-1 C C C C Example 2
TABLE-US-00003 TABLE 3 Bake SiON substrate Polymeric temperature
Block Lamella Cylinder compound (.degree. C.) copolymer pattern
pattern Example (A)-8 210 (BP)-3 -- A 11 Example (A)-8 230 (BP)-3 A
12 Example (A)-8 210 (BP)-4 B -- 13 Example (A)-8 230 (BP)-4 B --
14 Example (A)-9 210 (BP)-3 -- A 15 Example (A)-9 230 (BP)-3 -- A
16
[0497] In Tables 2 and 3, the reference characters indicate the
following.
[0498] (A)-1 to (A)-9: the aforementioned polymeric compounds 1 to
9
[0499] (G)-1: a compound represented by chemical formula (G)-1
shown below
[0500] (G)-2: nonafluorobutanesulfonate
[0501] (B)-1 and (B)-2: compounds represented by chemical formulas
(B)-1 and (B)-2 shown below, respectively
[0502] (BP)-1: a block copolymer of PS-PMMA (Mw=18000-18000,
Mw/Mn=1.07)
[0503] (BP)-2: a block copolymer of PS-PMMA (Mw=45000-20000,
Mw/Mn=1.07)
[0504] (BP)-3: a block copolymer of PS-PMMA (Mw=52000-20000,
Mw/Mn=1.08)
[0505] (BP)-4: a block copolymer of PS-PMMA (Mw=23000-20000,
Mw/Mn=1.07)
##STR00043##
[0506] From the results shown above, it was confirmed that, in the
case where the undercoat agents of Examples 1 to 16 according to
the present invention were used, a favorable pattern (vertical
lamella pattern or cylinder pattern) could be obtained by phase
separation of a layer containing a block copolymer, as compared to
the case where the undercoat agent of Comparative Examples 1 and 2
were used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0507] 1: substrate, 2: layer composed of undercoat agent, 3: layer
containing block copolymer, 3a: phase composed of P.sub.B block,
3b: phase composed of P.sub.A block
[0508] While preferred embodiments of the invention have been
described and illustrated above, it should be understood that these
are exemplary of the invention and are not to be considered as
limiting. Additions, omissions, substitutions, and other
modifications can be made without departing from the spirit or
scope of the present invention. Accordingly, the invention is not
to be considered as being limited by the foregoing description, and
is only limited by the scope of the appended claims.
* * * * *