U.S. patent application number 13/386230 was filed with the patent office on 2012-05-24 for composition for forming resist underlayer film for nanoimprint.
This patent application is currently assigned to NISSAN CHEMICAL INDUSTRIES, LTD.. Invention is credited to Tomoya Ohashi, Satoshi Takei.
Application Number | 20120128891 13/386230 |
Document ID | / |
Family ID | 43529285 |
Filed Date | 2012-05-24 |
United States Patent
Application |
20120128891 |
Kind Code |
A1 |
Takei; Satoshi ; et
al. |
May 24, 2012 |
COMPOSITION FOR FORMING RESIST UNDERLAYER FILM FOR NANOIMPRINT
Abstract
There is provided a composition for curing a resist underlayer
film used as an underlayer of a resist for nanoimprint in
nanoimprint lithography of a pattern forming process by
heat-baking, light-irradiation or both of them to form the resist
underlayer film. A composition for forming a resist underlayer film
used for nanoimprint in a pattern forming process using nanoimprint
by performing heat-baking, light-irradiation, or both of them, the
composition comprising a silicon atom-containing polymerizable
compound (A), a polymerization initiator (B) and a solvent (C). The
polymerizable compound (A) may contain silicon atoms in a content
of 5 to 45% by mass. The polymerizable compound (A) may be a
polymerizable compound having at least one cation polymerizable
reactive group, a polymerizable compound having at least one
radical polymerizable reactive group, or a combination of them, and
the polymerization initiator (B) may be a photopolymerization
initiator.
Inventors: |
Takei; Satoshi;
(Funabashi-shi, JP) ; Ohashi; Tomoya; (Toyama-shi,
JP) |
Assignee: |
NISSAN CHEMICAL INDUSTRIES,
LTD.
Tokyo
JP
|
Family ID: |
43529285 |
Appl. No.: |
13/386230 |
Filed: |
July 26, 2010 |
PCT Filed: |
July 26, 2010 |
PCT NO: |
PCT/JP2010/062545 |
371 Date: |
January 20, 2012 |
Current U.S.
Class: |
427/510 ;
522/170; 522/99; 977/887 |
Current CPC
Class: |
G03F 7/2051 20130101;
G03F 7/0002 20130101; B82Y 40/00 20130101; G03F 7/11 20130101; B82Y
10/00 20130101; C08G 77/14 20130101; G03F 7/0757 20130101; C08G
77/045 20130101; G03F 7/0752 20130101; C09D 183/06 20130101 |
Class at
Publication: |
427/510 ;
522/170; 522/99; 977/887 |
International
Class: |
B29C 59/02 20060101
B29C059/02; C08G 77/18 20060101 C08G077/18 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 29, 2009 |
JP |
2009-176165 |
Claims
1. A composition for forming a resist underlayer film used for
nanoimprint in a pattern forming process using nanoimprint by
performing heat-baking, light-irradiation, or both of them, the
composition comprising: a silicon atom-containing polymerizable
compound (A); a polymerization initiator (B); and a solvent
(C).
2. The composition for forming the resist underlayer film according
to claim 1, wherein the polymerizable compound (A) contains silicon
atoms in a content of 5 to 45% by mass.
3. The composition for forming the resist underlayer film according
to claim 1, wherein the polymerizable compound (A) is a
polymerizable compound having at least one cation polymerizable
reactive group, a polymerizable compound having at least one
radical polymerizable reactive group, or both of them and the
polymerization initiator (B) is a photopolymerization
initiator.
4. The composition for forming the resist underlayer film according
to claim 1, wherein the polymerizable compound (A) is a
polymerizable compound having at least one cation polymerizable
reactive group, a polymerizable compound having at least one
radical polymerizable reactive group, or both of them and the
polymerization initiator (B) is a thermopolymerization
initiator.
5. The composition for forming the resist underlayer film according
to claim 3, wherein the cation polymerizable reactive group is an
epoxy group, an oxetane group, or an organic group containing any
one of or both of them.
6. The composition for forming the resist underlayer film according
to claim 3, wherein the radical polymerizable reactive group is a
vinyl group or an organic group containing a vinyl group.
7. The composition for forming the resist underlayer film according
to claim 1, wherein the polymerizable compound (A) is a silicon
atom-containing polymerizable compound (A1) containing at least one
of organic silicon compound selected from a group consisting of an
organic silicon compound of Formula (I):
(R.sup.1).sub.a(R.sup.3).sub.bSi(R.sup.2).sub.4-(a+b) Formula (I)
(where R.sup.1 is an epoxy group, an oxetane group, a vinyl group,
or a polymerizable organic group which contains one to three of an
epoxy group, an oxetane group, and a vinyl group and is bonded to a
silicon atom through a Si--C bond; R.sup.3 is an alkyl group, an
aryl group, a halogenated alkyl group, a halogenated aryl group, or
an organic group which has a mercapto group, an amino group, or a
cyano group and is bonded to a silicon atom through a Si--C bond;
R.sup.2 is a halogen atom, a C.sub.1-8 alkoxy group, or an acyloxy
group; and a is an integer of 1, b is an integer of 0, 1, or 2,
where a+b is an integer of 1, 2, or 3) and an organic silicon
compound of Formula (II):
[(R.sup.4).sub.cSi(R.sup.5).sub.3-c].sub.2Y Formula (II) (where
R.sup.4 is an epoxy group, an oxetane group, a vinyl group, or a
polymerizable organic group which contains one to three of an epoxy
group, an oxetane group, and a vinyl group and is bonded to a
silicon atom through a Si--C bond; R.sup.5 is a halogen atom, a
C.sub.1-8 alkoxy group, or an acyloxy group; Y is an oxygen atom, a
methylene group, or a C.sub.2-20 alkylene group; and c is an
integer of 1 or 2), a hydrolysis product thereof, a
hydrolysis-condensation product thereof, or a mixture thereof.
8. The composition for forming the resist underlayer film according
to claim 1, wherein the polymerizable compound (A) is a combination
of a silicon atom-containing polymerizable compound (A1) containing
at least one of organic silicon compound selected from a group
consisting of the organic silicon compound of Formula (I) and the
organic silicon compound of Formula (II), a hydrolysis product
thereof, a hydrolysis-condensation product thereof, or a mixture
thereof, and a silicon atom-containing polymerizable compound (A2)
containing at least one of organic silicon compound selected from a
group consisting of an organic silicon compound of General Formula
(III):
(R.sup.11).sub.a.sub.1(R.sup.13).sub.b.sub.1Si(R.sup.12).sub.4-(a.sub.1.s-
ub.+b.sub.1.sub.) Formula (III) (where R.sup.11 and R.sup.13 are
individually an alkyl group, an aryl group, a halogenated alkyl
group, a halogenated aryl group, or an organic group which has a
mercapto group, an amino group, or a cyano group and is bonded to a
silicon atom through a Si--C bond; R.sup.12 is a halogen atom, a
C.sub.1-8 alkoxy group, or an acyloxy group; and a.sup.1 and
b.sup.1 are individually an integer of 0, 1, or 2, where
a.sup.1+b.sup.1 is an integer of 0, 1, or 2) and an organic silicon
compound of Formula (IV):
[(R.sup.14).sub.c.sub.1Si(X).sub.3-c.sub.1].sub.2Y Formula (IV)
(where R.sup.14 is a C.sub.1-5 alkyl group; X is a halogen atom, a
C.sub.1-8 alkoxy group, or an acyloxy group; Y.sup.1 is a methylene
group or a C.sub.2-20 alkylene group; and c.sup.1 is an integer of
0 or 1), a hydrolysis product thereof, a hydrolysis-condensation
product thereof, or a mixture thereof.
9. The composition for forming the resist underlayer film according
to claim 1, wherein the silicon atom-containing polymerizable
compound (A) contains a combination of a polymerizable compound
(A1) and a polymerizable compound (A2) in which an abundance ratio
between silicon atoms in (A1) and silicon atoms in (A2) in a molar
ratio is 100:0 to 50, and is a polymerizable organic
group-containing condensation product having a weight average
molecular weight of 100 to 100,000 produced by hydrolyzing the
polymerizable compound (A1) and the polymerizable compound (A2) and
by condensing the resultant hydrolyzed products.
10. The composition for forming the resist underlayer film
according to claim 1, wherein the silicon atom-containing
polymerizable compound (A): contains the organic silicon compound
of Formula (I) or a combination of the organic silicon compound of
Formula (I) and the organic silicon compound of Formula (III);
contains an organic silicon compound in which a value of a+b or a
value of a+b and a value of a.sup.1+b.sup.1 become(s) 1 in the
organic silicon compound of Formula (I) or in both of the organic
silicon compound of Formula (I) and the organic silicon compound of
Formula (III) in a ratio of 5 to 75% by mass; and is a
polymerizable organic group-containing condensation product having
a weight average molecular weight of 100 to 1,000,000 produced by
hydrolyzing the above organic silicon compounds and by condensing
the resultant hydrolyzed products.
11. The composition for forming the resist underlayer film
according to claim 7, wherein the polymerizable compound (A)
contains a thermally cation polymerizable reactive group and a
photo radical polymerizable reactive group in a molar ratio of
10:90 to 90:10.
12. The composition for forming the resist underlayer film
according to claim 1, further containing a crosslinkable compound,
a surface modifier, or both of them.
13. A forming method of a laminated structure used in a pattern
forming process using nanoimprint, the forming method comprising: a
process of applying the composition for forming the resist
underlayer film as claimed in claim 1 on a substrate to form a
resist underlayer film; a process of performing heat-baking,
light-irradiation, or both of them relative to the resist
underlayer film to cure the resist underlayer film; and a process
of applying a resist composition for nanoimprint on the resist
underlayer film and heat-baking the resultant coating to form a
resist for nanoimprint.
14. A forming method of a laminated structure used in a pattern
forming process using nanoimprint, the forming method comprising: a
process of applying the composition for forming the resist
underlayer film as claimed in claim 1 on a substrate to form a
resist underlayer film; a process of performing heat-baking,
light-irradiation, or both of them relative to the resist
underlayer film to cure the resist underlayer film; a process of
applying a resist composition for nanoimprint on the resist
underlayer film and heat-baking the resultant coating to form a
resist for nanoimprint; and a process of imprinting by a step and
repeat method.
15. The forming method according to claim 13, wherein the substrate
is a substrate which has a hole having an aspect ratio represented
by height/diameter of 0.01 or more or a step having an aspect ratio
represented by height/width of 0.01 or more.
16. The forming method according to claim 13, wherein the
light-irradiation is performed by a light having a wavelength of
250 nm to 650 nm.
Description
TECHNICAL FIELD
[0001] The present invention relates to a composition for forming
an underlayer film between a substrate to be processed and a resist
for nanoimprint. More in detail, the present invention relates to
an underlayer film forming composition for forming an underlayer
film used as an underlayer of a resist for nanoimprint in a pattern
forming process by performing heat-baking, light-irradiation, or
both of them. The present invention relates also to a forming
method of an underlayer film using the underlayer film forming
composition and a forming method of a resist pattern for
nanoimprint.
BACKGROUND ART
[0002] Conventionally in the production of semiconductor devices,
fine processing by photolithography using a photoresist has been
performed. The fine processing is a processing method for forming
fine convexo-concave shapes corresponding to the following pattern
on the surface of a substrate by: forming a thin film of a
photoresist on a semiconductor substrate such as a silicon wafer;
irradiating the resultant thin film with an active ray such as an
ultraviolet ray through a mask pattern in which a pattern of a
semiconductor device is depicted for development; and subjecting
the substrate to etching processing using the resultant photoresist
pattern as a protecting film. There is disclosed a method for
forming a cured film by irradiating an underlayer film of the
photoresist with light (Patent Document 1).
[0003] As a pattern forming method of the next generation,
nanoimprint lithography has attracted attention as one technology.
The nanoimprint lithography is a method entirely different from
conventional lithography using a light source. The nanoimprint
lithography is a method for producing a pattern symmetric to a
pattern of a template on a substrate by preparing a mold (template)
having a pattern symmetric to a pattern produced beforehand and by
directly pushing the mold into a resist applied on the substrate.
The nanoimprint lithography is characterized in that the resolution
of the nanoimprint lithography does not depend on the light source
wavelength in comparison with conventional photolithography, so
that an expensive apparatus such as an excimer laser exposing
apparatus and an electron beam drawing apparatus is not necessary,
and consequently, the cost therefor can be reduced (see, for
example, Patent Document 2 and Patent Document 3).
[0004] That is, the nanoimprint lithography is a pattern forming
method by: dropping by inkjet a composition of a resist for
nanoimprint onto an inorganic substrate such as silicon and
gallium, an oxide film, a nitride film, a quartz, a glass, or a
polymer film to apply the composition thereon in a film thickness
of about some ten nanometers to some micrometers; pressing a
template having a fine convexo-concave shape of about some ten
nanometers to some ten micrometers pattern size against the
composition to pressurize the composition; irradiating the
composition with light or heat-baking the composition while the
composition is in a pressurized state to cure the composition; and
releasing the template from the coating film to obtain a
transferred pattern. Therefore, in the case of the nanoimprint
lithography, for the convenience of performing light-irradiation,
it is necessary that at least any one of the substrate and the
template is transparent. Ordinarily, it is general to perform
light-irradiation from the template side, so that, as the material
for the template, there is used an optically transparent inorganic
material such as quartz and sapphire or a light transmittable
resin.
[0005] In order to apply the nanoimprint lithography to the imprint
of a nanometer-sized pattern in a large area, there are required
not only homogeneity of a pressure for pressing the template
against the composition and planarity of the template or the
surface of a base, but also the control of the behavior of a resist
for nanoimprint that is pressed-against and flows out. In
conventional semiconductor lithography, a region that is not used
as an element can optionally be set on a substrate to be processed,
so that a resist flow-out part can be provided using a small
template in the outside of an imprint part. In the case of a
semiconductor, it is satisfactory that an imprint defective part is
regarded as a defective element and not used. However, for example,
in the case of applying to a hard disc, the entirety functions as a
device, so that a special devisal for not causing an imprint defect
is necessary.
[0006] The nanoimprint lithography is a technology for patterning
by a physical contact, so that as the miniaturization is
progressed, there is easily caused a problem of a patterning loss
such as chipping and peeling of a pattern and foreign matters
caused by reattachment of the chipped or peeled pattern (see, for
example, Non-patent Document 1). Peeling properties between the
template and the resist for nanoimprint and adhesion between the
resist for nanoimprint and the base substrate to be processed are
important, so that conventionally, there has been attempted to
solve a problem of defect or foreign matters by surface modifying
treatment of the template or the resist.
[0007] The resist composition for nanoimprint is classified roughly
into a radical crosslinking type, a cation crosslinking type, and a
mixed type thereof according to the photoreaction mechanisms (see,
for example, Patent Document 4, Patent Document 5, and Patent
Document 6). The radical crosslinking type contains a compound
derivative having an ethylenic unsaturated bond and uses generally
a composition containing a polymerizable compound having a radical
polymerizable methacrylate, acrylate, or vinyl group and a
photocrosslinking initiator. On the other hand, the cation
crosslinking type uses generally a composition containing a
polymerizable compound that is a compound derivative having an
epoxy or oxetane ring and a photocrosslinking initiator. When such
a composition is irradiated with light, a radical or a cation that
is generated from the photocrosslinking initiator attacks the
ethylenic unsaturated bond or the epoxy or oxetane ring
respectively, and a chain polymerization and a crosslinking
reaction are progressed to form a three-dimensional network
structure. When a monomer or oligomer having a multifunctional
group such as a bifunctional or more group is used as a component,
a crosslinked structure can be obtained.
[0008] In addition, various resists are disclosed (see Non-patent
Document 2, Non-patent Document 3, and Patent Document 7).
[0009] Although the imprint lithography has previously existed, in
recent years, the imprint lithography has been studied also for the
formation of a fine nanopattem such as a nanopattem having some ten
nanometers. However, with respect to the nanoimprint lithography,
there is feared a defect caused by a direct physical contact of a
resist for nanoimprint with a template (see, for example, Patent
Document 8). Further, when a superposition or a large area is
transferred in a lump, there is caused a problem of peeling of a
resist for nanoimprint due to an adhesion failure between a
substrate to be processed and a resist for nanoimprint or a problem
of a variation of the film thickness of a resist for nanoimprint
due to an in-plane homogeneity.
[0010] Further, in recent years, there has been caused a problem of
lack of smoothness or planarity at a nano level that has become
apparent according to the miniaturization of a thin line width of a
pattern (see, for example, Patent Document 9). That is, following
the miniaturization, a step or a via hole is formed on a substrate
to be processed and a resist for nanoimprint is formed on a
substrate to be processed having a large aspect ratio. Therefore,
for the resist for nanoimprint used in this process, besides a
characteristic of pattern forming, a characteristic of capable of
controlling coating properties of a substrate around a step or a
via hole, an embedding characteristic capable of filling a via hole
without void, a planarizing characteristic capable of forming a
planar film on the surface of a substrate, and the like are
required. However, it is difficult to apply a resist for
nanoimprint to a substrate having a large aspect ratio.
[0011] With respect to an attempt to add an underlayer film between
a substrate to be processed and a resist for nanoimprint for
solving these problems, there is conventionally no disclosure of a
resist underlayer film for nanoimprint for being suitably used or
no guideline for designing a material for the underlayer film. In a
process for the purpose of imparting adhesion or planarity to a
resist underlayer film for imprint known as an application for
conventional macroimprint lithography, although some materials
therefor are common with those for a resist underlayer film for
nanoimprint, the above planarity is largely different from
planarity characteristic on a fine pattern shape having a nanometer
width or on a step or via hole having a nanometer width. Therefore,
when an underlayer film applied to nanoimprint lithography is
applied to nanoimprint lithography, there are frequently caused
such problems as peeling of a resist for nanoimprint due to a
failure of adhesion between a substrate to be processed and a
resist for nanoimprint, an etching failure due to a variation of
the film thickness of a resist for nanoimprint due to in-plane
homogeneity, and peeling of a resist for nanoimprint due to a
failure of surface smoothness or planarity.
RELATED-ART DOCUMENT
Patent Document
[0012] Patent Document 1: International Publication No. WO
2007/066597 pamphlet
[0013] Patent Document 2: Japanese Patent Application Publication
No. 2006-287012
[0014] Patent Document 3: Japanese Patent Application Publication
No. 2007-305647
[0015] Patent Document 4: Japanese Patent Application Publication
No. 2007-072374
[0016] Patent Document 5: Japanese Patent Application Publication
No. 2008-105414
[0017] Patent Document 6: Japanese Patent Application Publication
No. 2009-51017
[0018] Patent Document 7: Japanese Patent Application Publication
No. 2006-114882
[0019] Patent Document 8: Japanese Patent Application Publication
No. 2005-159358
[0020] Patent Document 9: Japanese Patent Application Publication
No. 2005-532576
Non-Patent Document
[0021] Non-patent Document 1: I. McMackin, et. al., Proc. of SPIE
6921, 69211L (2008)
[0022] Non-patent Document 2: Jianjun Hao et. al., Proc. of SPIE
6517, 651729 (2007)
[0023] Non-patent Document 3: Ken-ichiro Nakamatsu et. al.,
Japanese Journal of Applied Physics 44, 8186 (2005)
DISCLOSURE OF THE INVENTION
Problem to be Solved by the Invention
[0024] The present invention has been invented in the light of the
present situation described above. That is, it is an object of the
present invention to provide a silicon atom-containing resist
underlayer film forming composition for curing a resist underlayer
film used as an underlayer of a resist for nanoimprint in
nanoimprint lithography of a pattern forming process by
light-irradiation or heat-baking to form the resist underlayer
film. It is also an object of the present invention to provide a
forming method of an underlayer film used as an underlayer of a
resist for nanoimprint in nanoimprint lithography of a pattern
forming process using the composition, a forming method of a
laminated structure used in nanoimprint lithography of a pattern
forming process using the composition, and a forming method of a
resist pattern for nanoimprint.
Means for Solving the Problem
[0025] As a result of assiduous research intended to solve these
problems, the inventor of the present invention has found that a
composition containing, as components, a polymerizable compound (A)
having a small content of low molecular weight components and
containing silicon atoms in a content of 5 to 45% by mass, a
polymerization initiator (B), and a solvent (C) is suitable as a
material for forming a resist underlayer film for nanoimprint, and
has completed the present invention.
[0026] That is, the present invention is, according to a first
aspect, a composition for forming a resist underlayer film used for
nanoimprint in a pattern forming process using nanoimprint by
performing heat-baking, light-irradiation, or both of them, the
composition containing a silicon atom-containing polymerizable
compound (A), a polymerization initiator (B), and a solvent
(C);
[0027] according to a second aspect, the composition for forming
the resist underlayer film according to the first aspect, in which
the polymerizable compound (A) contains silicon atoms in a content
of 5 to 45% by mass;
[0028] according to a third aspect, the composition for forming the
resist underlayer film according to the first aspect or the second
aspect, in which the polymerizable compound (A) is a polymerizable
compound having at least one cation polymerizable reactive group, a
polymerizable compound having at least one radical polymerizable
reactive group, or both of them and the polymerization initiator
(B) is a photopolymerization initiator;
[0029] according to a fourth aspect, the composition for forming
the resist underlayer film according to the first aspect or the
second aspect, in which the polymerizable compound (A) is a
polymerizable compound having at least one cation polymerizable
reactive group, a polymerizable compound having at least one
radical polymerizable reactive group, or both of them and the
polymerization initiator (B) is a thermopolymerization
initiator;
[0030] according to a fifth aspect, the composition for forming the
resist underlayer film according to the third aspect or the fourth
aspect, in which the cation polymerizable reactive group is an
epoxy group, an oxetane group, or an organic group containing any
one of or both of them;
[0031] according to a sixth aspect, the composition for forming the
resist underlayer film according to the third aspect or the fourth
aspect, in which the radical polymerizable reactive group is a
vinyl group or an organic group containing a vinyl group;
[0032] according to a seventh aspect, the composition for forming
the resist underlayer film according to any one of the first aspect
to the sixth aspect, in which the polymerizable compound (A) is a
silicon atom-containing polymerizable compound (A1) containing at
least one of organic silicon compound selected from a group
consisting of an organic silicon compound of Formula (I):
(R.sup.1).sub.a(R.sup.3).sub.bSi(R.sup.2).sub.4-(a+b) Formula
(I)
[0033] (where R.sup.1 is an epoxy group, an oxetane group, a vinyl
group, or a polymerizable organic group which contains one to three
of an epoxy group, an oxetane group, and a vinyl group and is
bonded to a silicon atom through a Si--C bond; R.sup.3 is an alkyl
group, an aryl group, a halogenated alkyl group, a halogenated aryl
group, or an organic group which has a mercapto group, an amino
group, or a cyano group and is bonded to a silicon atom through a
Si--C bond; R.sup.2 is a halogen atom, a C.sub.1-8 alkoxy group, or
an acyloxy group; and a is an integer of 1, b is an integer of 0,
1, or 2, where a+b is an integer of 1, 2, or 3) and
an organic silicon compound of Formula (II):
[(R.sup.4).sub.cSi(R.sup.5).sub.3-c].sub.2Y Formula (II)
[0034] (where R.sup.4 is an epoxy group, an oxetane group, a vinyl
group, or a polymerizable organic group which contains one to three
of an epoxy group, an oxetane group, and a vinyl group and is
bonded to a silicon atom through a Si--C bond; R.sup.5 is a halogen
atom, a C.sub.1-8 alkoxy group, or an acyloxy group; Y is an oxygen
atom, a methylene group, or a C.sub.2-20 alkylene group; and c is
an integer of 1 or 2), a hydrolysis product thereof, a
hydrolysis-condensation product thereof, or a mixture thereof;
[0035] according to an eighth aspect, the composition for forming
the resist underlayer film according to any one of the first aspect
to the sixth aspect, in which the polymerizable compound (A) is a
combination of a silicon atom-containing polymerizable compound
(A1) containing at least one of organic silicon compound selected
from a group consisting of the organic silicon compound of Formula
(I) and the organic silicon compound of Formula (II), a hydrolysis
product thereof, a hydrolysis-condensation product thereof, or a
mixture thereof, and a silicon atom-containing polymerizable
compound (A2) containing at least one of organic silicon compound
selected from a group consisting of an organic silicon compound of
General Formula (III):
(R.sup.11).sub.a.sub.1(R.sup.13).sub.b.sub.1Si(R.sup.12).sub.4-(a.sub.1.-
sub.+b.sub.1.sub.) Formula (III)
[0036] (where R.sup.11 and R.sup.13 are individually an alkyl
group, an aryl group, a halogenated alkyl group, a halogenated aryl
group, or an organic group which has a mercapto group, an amino
group, or a cyano group and is bonded to a silicon atom through a
Si--C bond; R.sup.12 is a halogen atom, a C.sub.1-8 alkoxy group,
or an acyloxy group; and a.sup.1 and b.sup.1 are individually an
integer of 0, 1, or 2, where a.sup.1+b.sup.1 is an integer of 0, 1,
or 2) and
an organic silicon compound of Formula (IV):
[(R.sup.14).sub.c.sub.1Si(X).sub.3-c.sub.1].sub.2Y Formula (IV)
[0037] (where R.sup.14 is a C.sub.1-5 alkyl group; X is a halogen
atom, a C.sub.1-8 alkoxy group, or an acyloxy group; Y.sup.1 is a
methylene group or a C.sub.2-20 alkylene group; and c.sup.1 is an
integer of 0 or 1), a hydrolysis product thereof, a
hydrolysis-condensation product thereof, or a mixture thereof;
[0038] according to a ninth aspect, the composition for forming the
resist underlayer film according to any one of the first aspect to
the sixth aspect, in which the silicon atom-containing
polymerizable compound (A) contains a combination of a
polymerizable compound (A1) and a polymerizable compound (A2) in
which an abundance ratio between silicon atoms in (A1) and silicon
atoms in (A2) in a molar ratio is 100:0 to 50, and is a
polymerizable organic group-having condensation product having a
weight average molecular weight of 100 to 100,000 produced by
hydrolyzing the polymerizable compound (A1) and the polymerizable
compound (A2) and by condensing the resultant hydrolyzed
products;
[0039] according to a tenth aspect, the composition for forming the
resist underlayer film according to any one of the first aspect to
the sixth aspect, in which the silicon atom-containing
polymerizable compound (A): contains the organic silicon compound
of Formula (I) or a combination of the organic silicon compound of
Formula (I) and the organic silicon compound of Formula (III);
contains an organic silicon compound in which a value of a+b or a
value of a+b and a value of a.sup.1+b.sup.1 become(s) 1 in the
organic silicon compound of Formula (I) or in both of the organic
silicon compound of Formula (I) and the organic silicon compound of
Formula (III) in a ratio of 5 to 75% by mass; and is a
polymerizable organic group-having condensation product having a
weight average molecular weight of 100 to 1,000,000 produced by
hydrolyzing the above organic silicon compounds and by condensing
the resultant hydrolyzed products;
[0040] according to an eleventh aspect, the composition for forming
the resist underlayer film according to any one of the seventh
aspect to the tenth aspect, in which the polymerizable compound (A)
contains a thermally cation polymerizable reactive group and a
photo radical polymerizable reactive group in a molar ratio of
10:90 to 90:10;
[0041] according to a twelfth aspect, the composition for forming
the resist underlayer film according to any one of the first aspect
to the eleventh aspect further containing a crosslinkable compound,
a surface modifier, or both of them;
[0042] according to a thirteenth aspect, a forming method of a
laminated structure used in a pattern forming process using
nanoimprint, the forming method including: a process of applying
the composition for forming the resist underlayer film as described
in the first aspect to the twelfth aspect on a substrate to form a
resist underlayer film; a process of performing heat-baking,
light-irradiation, or both of them relative to the resist
underlayer film to cure the resist underlayer film; and a process
of applying a resist composition for nanoimprint on the resist
underlayer film and heat-baking the resultant coating to form a
resist for nanoimprint;
[0043] according to a fourteenth aspect, a forming method of a
laminated structure used in a pattern forming process using
nanoimprint, the forming method including: a process of applying
the composition for forming the resist underlayer film as described
in the first aspect to the twelfth aspect on a substrate to form a
resist underlayer film; a process of performing heat-baking,
light-irradiation, or both of them relative to the resist
underlayer film to cure the resist underlayer film; a process of
applying a resist composition for nanoimprint on the resist
underlayer film and heat-baking the resultant coating to form a
resist for nanoimprint; and a process of imprinting by a step and
repeat method;
[0044] according to a fifteenth aspect, the forming method
according to the thirteenth aspect or the fourteenth aspect, in
which the substrate is a substrate which has a hole having an
aspect ratio represented by height/diameter of 0.01 or more or a
step having an aspect ratio represented by height/width of 0.01 or
more; and
[0045] according to a sixteenth aspect, the forming method
according to any one of the thirteenth aspect to the fifteenth
aspect, in which the light-irradiation is performed by a light
having a wavelength of 250 nm to 650 nm.
Effects of the Invention
[0046] A resist underlayer film obtained by performing heat-baking,
light-irradiation, or both of them relative to the resist
underlayer film forming composition of the present invention
exhibits applying-type hardmask characteristics having a dry
etching rate smaller than that of a resist under an oxygen gas
condition and has a dry etching rate larger than that of a resist
under a fluorine-based gas (such as CF.sub.4) condition.
[0047] The resist underlayer film forming composition of the
present invention contains silicon atoms that are an inorganic atom
derived from an organic silicon compound in a content of 5 to 45%
by mass, so that the plasma etching rate of the resist underlayer
film forming composition by an oxygen gas becomes smaller and the
resist underlayer film forming composition becomes an
etching-resistant hardmask layer.
[0048] A fluorine-based gas (such as CF.sub.4) used during etching
according to a resist pattern of the resist underlayer film of the
present invention has a satisfactorily high etching rate relative
to the resist underlayer film of the present invention in
comparison with an etching rate relative to a resist. Thus, it is
possible that according to the resist pattern, the resist
underlayer film of the present invention is removed by etching to
transfer the resist pattern to the underlayer film of the present
invention, and by using the formed resist film and the formed
resist underlayer film as a protecting film, the substrate can be
processed.
[0049] Further, a resist underlayer film obtained from the resist
underlayer film forming composition exhibits high adhesion to a
resist for nanoimprint and a base substrate and is excellent in
peeling properties between a template and a resist for
nanoimprint.
[0050] After a template having a fine convexo-concave shape is
pressed against a resist for nanoimprint formed on the resist
underlayer film to pressurize the resist and the resist composition
is cured by light-irradiation or heat-baking while the composition
is in a pressurized state, when the template is released from the
coating film, by high adhesion between the underlayer film of the
present invention and the resist for nanoimprint, it is less likely
to cause a problem of a patterning loss such as chipping, collapse,
and peeling of a resist pattern and foreign matters caused by
reattachment of resist pieces.
[0051] The underlayer film of the present invention has excellent
planarity and excellent surface smoothness and planarizes an
unevenness of a base substrate, so that the underlayer film can
homogenize the film thickness of a resist formed as an upper layer
of the underlayer film, and as a result thereof, the underlayer
film brings high resolution in a lithography process.
[0052] Further, the resist underlayer film of the present invention
causes no intermixing with a resist formed as an upper layer of the
resist underlayer film, is insoluble in a photoresist solvent,
causes no diffusion of a low molecular weight substance from the
underlayer film to the resist film as an upper layer of the resist
underlayer film during application or heating-drying, and has an
advantageous rectangular nano-patterning characteristic.
[0053] Depending on the application, when photo-crosslinking is
applied to the resist underlayer film forming composition of the
present invention, the resist underlayer film can be formed by
light-irradiation without performing heat-baking at a high
temperature. Therefore, a contamination of peripheral equipment by
volatilization or sublimation of a low molecular weight component
can be prevented. Further, heat-baking at a high temperature is not
required, so that when a low molecular weight component is used in
the resist underlayer film forming composition, there is no fear of
sublimation or the like and a relatively large amount of a low
molecular weight component can be used in the resist underlayer
film forming composition. Therefore, by using a resist underlayer
film forming composition having a relatively low viscosity, the
resist underlayer film can be formed. Then, there can also be
formed a resist underlayer film further more excellent in filling
properties of a hole and planarizing properties of a semiconductor
substrate.
[0054] By the forming method of a laminated structure used in a
pattern forming process using nanoimprint of the present invention,
in processing of a substrate, a high resolution is achieved and it
is also possible to process a substrate having a large aspect
ratio.
MODES FOR CARRYING OUT THE INVENTION
[0055] The present invention is a composition for forming a resist
underlayer film for nanoimprint in a pattern forming process using
nanoimprint by performing heat-baking, light-irradiation, or both
of them. The composition for forming a resist underlayer film for
nanoimprint containins a silicon atom-containing polymerizable
compound (A), a polymerization initiator (B), and a solvent
(C).
[0056] The polymerizable compound (A) is a polymerizable organic
group-containing organic silicon compound, a hydrolysis product of
the polymerizable organic group-containing organic silicon
compound, a condensation product of the hydrolysis product of the
polymerizable organic group-containing organic silicon compound, or
a mixture thereof.
[0057] The polymerizable compound (A) is a polymerizable compound
having at least one cation polymerizable reactive group, a
polymerizable compound having at least one radical polymerizable
reactive group, or a combination thereof, and as the polymerization
initiator (B), a photopolymerization initiator can be used.
[0058] By irradiating an underlayer film containing the
polymerizable compound (A) with light and by an action of a photo
cation polymerization initiator, the cation polymerization of the
polymerizable compound (A) is progressed to form an underlayer
film. Then, the cation polymerizable reactive group is preferably
an epoxy group, an oxetane group, or an organic group containing
any one of or both of them. When the polymerizable compound (A) is
the condensation product, it is preferred, in terms of the
solvent-dissolution resistance to a solvent of an overcoated
photoresist, that the condensation product have two or more epoxy
groups that are a polymerizable moiety.
[0059] The polymerizable compound (A) is a polymerizable compound
having at least one radical polymerizable ethylenic unsaturated
bond such as a vinyl group and an organic group containing a vinyl
group, and as the photopolymerization initiator, a photo radical
polymerization initiator can be used. By irradiating an underlayer
film containing the polymerizable compound (A) with light and by an
action of the photo radical polymerization initiator, the radical
polymerization of the polymerizable compound (A) is progressed to
form the underlayer film. Then, the ethylenic unsaturated bond is
preferably a vinyl group. The vinyl group is preferably an organic
group containing an acryloxy group or a methacryloxy group. When
the polymerizable compound (A) is the condensation product, it is
preferred, in terms of the solvent-dissolution resistance of the
resist underlayer film relative to a solvent of an overeoated
photoresist, that the condensation product have two or more vinyl
groups that are a polymerizable moiety.
[0060] For the cation polymerization, a thermo cation
polymerization initiator or a photo cation polymerization initiator
can be used.
[0061] For the radical polymerization, a thermo radical
polymerization initiator or a photo radical polymerization
initiator can be used.
[0062] As the polymerizable compound (A), there can be used a
combination of a polymerizable compound having at least one cation
polymerizable reactive group and a polymerizable compound having at
least one radical polymerizable reactive group, and as the
polymerization initiator (B), a photopolymerization initiator can
be used. By irradiating the resist underlayer film with light, the
photo cation polymerization and the photo radical polymerization
are progressed to form the resist underlayer film. By performing
heat-baking before performing light-irradiation, the
thermopolymerization is progressed and then, by performing
light-irradiation, the photo cation polymerization and the photo
radical polymerization are progressed, so that the resist
underlayer film can also be formed.
[0063] By performing heat-baking before performing
light-irradiation, the thermopolymerization by a cation
polymerizable reactive group (such as an epoxy group and an epoxy
group-containing organic group) is progressed and then, by
performing light-irradiation, the photo radical polymerization by a
radical polymerizable reactive group (a vinyl group or a vinyl
group-containing organic group) is progressed, so that the resist
underlayer film can also be formed.
[0064] The polymerizable compound (A) may contain a thermally
cation polymerizable reactive group and a photo radical
polymerizable reactive group in a ratio of 10:90 to 90:10.
[0065] Before the photopolymerization is performed, the contact
angle of the surface of the resist underlayer film is high, so that
when the resist underlayer film forming composition is applied on a
substrate, the liquid easily spreads on the surface of the
substrate. Then, after the photopolymerization is performed, the
contact angle of the surface of the resist underlayer film becomes
lower, so that the resist underlayer film is excellent in the
adhesion thereof to a resist film overcoated on the surface of the
resist underlayer film. The adhesion is easily influenced
particularly by a vinyl group and there can be used a method for
enhancing the adhesion of the resist underlayer film to the
overcoated resist. The method includes: enhancing the contact angle
of the resist underlayer film before performing the photo radical
polymerization to spread the resist underlayer film forming
composition on the substrate and to satisfactorily enhance the
planarity of the resist underlayer film; and then lowering the
contact angle of the resist underlayer film after performing the
photo radical polymerization.
[0066] In the present invention, as the silicon atom-containing
polymerizable compound (A), there can be used a silicon
atom-containing polymerizable compound (A1) containing at least one
of organic silicon compound selected from a group consisting of an
organic silicon compound of Formula (I):
(R.sup.1).sub.a(R.sup.3).sub.bSi(R.sup.2).sub.4-(a+b) Formula
(I)
[0067] (where R.sup.1 is an epoxy group, an oxetane group, a vinyl
group, or a polymerizable organic group which contains one to three
of an epoxy group, an oxetane group, and a vinyl group and is
bonded to a silicon atom through a Si--C bond; R.sup.3 is an alkyl
group, an aryl group, a halogenated alkyl group, a halogenated aryl
group, or an organic group which has a mercapto group, an amino
group, or a cyano group and is bonded to a silicon atom through a
Si--C bond; R.sup.2 is a halogen atom, a C.sub.1-8 alkoxy group, or
an acyloxy group; and a is an integer of 1, b is an integer of 0,
1, or 2, where a+b is an integer of 1, 2, or 3) and
an organic silicon compound of Formula (II):
[(R.sup.4).sub.cSi(R.sup.5).sub.3-c].sub.2Y Formula (II)
[0068] (where R.sup.4is an epoxy group, an oxetane group, a vinyl
group, or a polymerizable organic group which contains one to three
of an epoxy group, an oxetane group, and a vinyl group and is
bonded to a silicon atom through a Si--C bond; R.sup.5 is a halogen
atom, a C.sub.1-8 alkoxy group, or an acyloxy group; Y is an oxygen
atom, a methylene group, or a C.sub.2-20 alkylene group; and c is
an integer of 1 or 2), a hydrolysis product thereof, a
hydrolysis-condensation product thereof, or a mixture thereof.
[0069] Preferred examples of the organic silicon compound of
Formula (1) corresponding to the polymerizable compound (A1)
include: a vinyl group-containing silane compound such as
methacrylamidetrimethoxysilane,
2-methacryloxyethyltrimethoxysilane,
(methacryloxymethyl)bis(trimethyloxy)methylsilane,
methacryloxymethyltriethoxysilane,
methacryloxymethyltrimethoxysilane,
3-methacryloxypropyldimethylchlorosilane,
2-methacryloxyethyltrimethoxysilane,
3-methacryloxypropyldimethylethoxysilane,
3-methacryloxypropyldimethylmethoxysilane,
3-methacryloxypropyltrichiorosilane,
3-methacryloxypropylmethyldiethoxysilane,
3-methacryloxypropylmethyldimethoxysilane,
3-methacryloxypropyltripropoxysilane,
3-methacryloxypropyltrichlorosilane,
3-methacryloxypropyltriethoxysilane,
3-methacryloxypropyltrimethoxysilane,
2-methacryloxypropyltrimethoxysilane,
3-methacryloxypropyltris(methoxyethyl)silane,
methacryloxytrimethoxysilane, methacryloxytributoxysilane,
methacryloxytriisopropoxysilane, methacryloxytriphenoxysilane,
methacryloxyphenyldimethoxysilane,
methacryloxyphenylmethylmethoxysilane,
methacryloxyphenyldichlorosilane, methacryloxyphenyldimethylsilane,
methacryloxyphenyldiethoxysilane, methacryloxyphenyldichlorosilane,
methacryloxytrimethoxysilane, methacryloxymethyldimethoxysilane,
methacryloxymethyldiethoxysilane,
methacryloxymethyldiacetoxysilane,
methacryloxydiphenylehlorosilane, acrylamidetrimethoxysilane,
2-acryloxyethyltrimethoxysilane,
(acryloxymethyl)bis(trimethyloxy)methylsilane,
acryloxymethyltriethoxysilane, acryloxymethyltrimethoxysilane,
3-acryloxypropyldimethylchlorosilane,
2-acryloxyethyltrimethoxysilane,
3-acryloxypropyldimethylethoxysilane,
3-acryloxypropyldimethylmethoxysilane,
3-acryloxypropyltrichlorosilane,
3-acryloxypropylmethyldiethoxysilane,
3-acryloxypropylmethyldimethoxysilane,
3-acryloxypropyltripropoxysilane, 3-acryloxypropyltrichlorosilane,
3-acryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane,
2-acryloxypropyltrimethoxysilane,
3-acryloxypropyltris(methoxyethyl)silane, acryloxytrimethoxysilane,
acryloxytributoxysilane, acryloxytriisopropoxysilane,
acryloxytriphenoxysilane, acryloxyphenyldimethoxysilane,
acryloxyphenylmethylmethoxysilane, acryloxyphenyldichlorosilane,
acryloxyphenyldimethoxysilane, acryloxyphenyldiethoxysilane,
acryloxyphenyldichlorosilane, acryloxytrimethoxysilane,
acryloxymethyldimethoxysilane, acryioxymethyldiethoxysilane,
acryloxymethyldiacetoxysilane, and
acryloxydiphenylchlorosilane;
[0070] and an epoxy group-containing silane compound such as
glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane,
.alpha.-glycidoxyethyltrimethoxysilane,
.alpha.-glycidoxyethyltriethoxysilane,
.beta.-glycidoxyethyltrimethoxysilane,
.beta.-glycidoxyethyltriethoxysilane,
.alpha.-glycidoxypropyltrimethoxysilane,
.alpha.-glycidoxypropyltriethoxysilane,
.beta.-glycidoxypropyltrimethoxysilane,
.beta.-glycidoxypropyltriethoxysilane,
.gamma.-glycidoxypropyltrimethoxysilane,
.gamma.-glycidoxypropyltriethoxysilane,
.gamma.-glycidoxypropyltripropoxysilane,
.gamma.-glycidoxypropyltributoxysilane,
.gamma.-glycidoxypropyltriphenoxysilane,
.alpha.-glycidoxybutyltrimethoxysilane,
.alpha.-glycidoxybutyltriethoxysilane,
.beta.-glycidoxybutyltriethoxysilane,
.gamma.-glycidoxybutyltrimethoxysilane,
.gamma.-glycidoxybutyltriethoxysilane,
.delta.-glycidoxybutyltrimethoxysilane,
.delta.-glycidoxybutyltriethoxysilane,
(3,4-epoxycyclohexyl)methyltrimethoxysilane,
(3,4-epoxycyclohexyl)methyltriethoxysilane,
.beta.-(3,4-epoxycyclohexyl)pethyltrimethoxysilane,
.beta.-(3,4-epoxycyclohexyl) ethyltriethoxysilane,
.beta.-(3,4-epoxycyclohexyl)ethyltripropoxysilane,
.beta.-(3,4-epoxycyclohexyl)ethyltributoxysilane,
.beta.-(3,4-epoxycyclohexyl)ethyltriphenoxysilane,
.gamma.-(3,4-epoxycyclohexyl)propyltrimethoxysilane,
.gamma.-(3,4-epoxycyclohexyl)propyltriethoxysilane,
.delta.-(3,4-epoxycyclohexyl)butyltrimethoxysilane,
.delta.-(3,4-epoxycyclohexyl)butyltriethoxysilane,
glycidoxymethylmethyldimethoxysilane,
glycidoxymethylmethyldiethoxysilane,
.alpha.-glycidoxyethylmethyldimethoxysilane,
.alpha.-glycidoxyethyhnethyldiethoxysilane,
.beta.-glycidoxyethylmethyldimethoxysilane,
.beta.-glycidoxyethylethyldimethoxysilane,
.alpha.-glycidoxypropylmethyldimethoxysilane,
.alpha.-glycidoxypropylmethyldiethoxysilane,
.beta.-glycidoxypropylmethyldimethoxysilane,
.beta.-glycidoxypropylethyldimethoxysilane,
.gamma.-glycidoxypropylmethyldimethoxysilane,
.gamma.-glycidoxypropylmethyldiethoxysilane,
.gamma.-glycidoxypropylmethyldipropoxysilane,
.gamma.-glycidoxypropylmethyldibutoxysilane,
.gamma.-glycidoxypropylmethyldiphenoxysilane,
.gamma.-glycidoxypropylethyldimethoxysilane,
.gamma.-glycidoxypropylethyldiethoxysilane,
.gamma.-glycidoxypropylvinyldimethoxysilane, and
.gamma.-glycidoxypropylvinyldiethoxysilane.
[0071] Preferred examples of the organic silicon compound of
Formula (II) corresponding to the polymerizable compound (A1)
include: an epoxy group-containing silane compound such as
bis[2-(3,4-epoxycyclohexyl)ethyl]tetramethyldisiloxane,
di(glycidoxypropyl)tetramethyldisiloxane, and
di(glycidoxypropyl)tetraphenyldisiloxane; and a vinyl
group-containing silane compound such as
di(3-methacryloxypropyl)tetramethyldisiloxane, di(3
-methacryloxypropyl)tetraphenyldisiloxane,
di(3-acryloxypropyl)tetramethyldisiloxane, and
di(3-acryloxypropyl)tetraphenyldisiloxane.
[0072] Preferred examples of the organic silicon compound of
Formula (II) corresponding to the polymerizable compound (A1)
include: an epoxy group-containing silane compound such as
bis[2-(3,4-epoxycyclohexyl)ethyl]tetramethyldisiloxane,
di(glycidoxypropyl)tetramethyldisiloxane, and
di(glycidoxypropyl)tetraphenyldisiloxane; and a vinyl
group-containing silane compound such as di(3
-methacryloxypropyl)tetramethyldisiloxane,
di(3-methacryloxypropyl)tetraphenyldisiloxane,
di(3-acryloxypropyl)tetramethyldisiloxane, and
di(3-acryloxypropyl)tetraphenyldisiloxane,
[0073] The polymerizable compound (A1) is a silicon atom-containing
polymerizable compound (A1) containing at least one of organic
silicon compound selected from a group consisting of the organic
silicon compound of Formula (I) and the organic silicon compound of
Formula (II), a hydrolysis product thereof, a
hydrolysis-condensation product thereof, or a mixture thereof.
[0074] In the present invention, for the purpose of improving
etching resistance, wettability with the resist, gas permeability,
preservation stability, wettability with the substrate, and the
like of the resist underlayer film, the polymerizable compound (A1)
can be combined with a silicon atom-containing polymerizable
compound (A2) containing no polymerizable organic group such as an
epoxy group and a vinyl group.
[0075] The silicon atom-containing polymerizable compound (A2) is a
silicon atom-containing compound containing at least one of organic
silicon compound selected from a group consisting of
an organic silicon compound of General Formula (III):
(R.sup.11).sub.a.sub.1(R.sup.13).sub.b.sub.1Si
(R.sup.12).sub.4-(a.sub.l.sub.+b.sub.1.sub.) Formula (III)
[0076] (where R.sup.11 and R.sup.13 are individually an alkyl
group, an aryl group, a halogenated alkyl group, a halogenated aryl
group, or an organic group which has a mercapto group, an amino
group, or a cyano group and is bonded to a silicon atom through a
Si--C bond; R.sup.12 is a halogen atom, a C.sub.1-8 alkoxy group,
or an acyloxy group; and a and b are individually an integer of 0,
1, or 2, where a+b is an integer of 0, 1, or 2) and an organic
silicon compound of Formula (IV):
[(R.sup.14).sub.c.sub.1Si(X).sub.3-c.sub.1].sub.2Y Formula (IV)
[0077] (where R.sup.14 is a C.sub.1-5 alkyl group; X is a halogen
atom, a C.sub.1-8 alkoxy group, or an acyloxy group; Y is a
methylene group or a C.sub.2-20 alkylene group; and c.sup.1 is an
integer of 0 or 1), a hydrolysis product thereof, a
hydrolysis-condensation product thereof, or a mixture thereof.
[0078] Preferred examples of the organic silicon compound of
Formula (III) corresponding to the polymerizable compound (A2)
include tetramethoxysilane, tetraethoxysilane, tetra
n-propoxysilane, tetraisopropoxysilane, tetra n-butoxysilane,
tetraacetoxysilane, methyltrimethoxysilane, methyltripropoxysilane,
methyltriacetoxysilane, methyltributoxysilane,
methyltripropoxysilane, methyltriamyloxysilane,
methyltriphenoxysilane, methyltribenzyloxysilane,
methyltriphenethyloxysilane, ethyltrimethoxysilane,
ethyltriethoxysilane, phenyltrimethoxysilane,
phenyltriethoxysilane, phenyltriacetoxysilane,
.gamma.-chloropropyltrimethoxysilane,
.gamma.-chloropropyltriethoxysilane,
.gamma.-chloropropyltriacetoxysilane,
3,3,3-trifluoropropyltrimethoxysilane,
.gamma.-mercaptopropyltrimethoxysilane,
.gamma.-mercaptopropyltriethoxysilane,
.beta.-cyanoethyltriethoxysilane, chloromethyltrimethoxysilane,
chloromethyltriethoxysilane,
N-(.beta.-aminoethyl).gamma.-aminopropyltrimethoxysilane,
N-(.beta.-aminoethyl).gamma.-aminopropylmethyldimethoxysilane,
.gamma.-aminopropylmethyldimethoxysilane,
N-(.beta.-aminoethyl).gamma.-aminopropyltriethoxysilane,
N-(.beta.-aminoethyl)y-aminopropylmethyldiethoxysilane,
dimethyldimethoxysilane, phenylmethyldimethoxysilane,
dimethyldiethoxysilane, phenylmethyldiethoxysilane,
.gamma.-chloropropylmethyldimethoxysilane,
.gamma.-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane,
.gamma.-methacryloxypropylmethyldimethoxysilane,
.gamma.-methacryloxypropylmethyldiethoxysilane,
.gamma.-mercaptopropylmethyldimethoxysilane,
.gamma.-mercaptomethyldiethoxysilane, methylvinyldimethoxysilane,
and methylvinyldiethoxysilane.
[0079] Preferred examples of the organic silicon compound of
Formula (IV) corresponding to the polymerizable compound (A2)
include methylenebismethyldimethoxysilane,
ethylenebisethyldimethoxysilane, propylenebisethyldiethoxysilane,
and butylenebismethyldiethoxysilane.
[0080] The polymerizable compound (A2) is a silicon atom-containing
polymerizable compound (A2) containing at least one of organic
silicon compound selected from a group consisting of the organic
silicon compound of Formula (III) and the organic silicon compound
of Formula (IV), a hydrolysis product thereof, a
hydrolysis-condensation product thereof, or a mixture thereof.
[0081] In the present invention, the silicon atom-containing
polymerizable compound (A) contains the polymerizable compound (A1)
or a combination of the polymerizable compound (A1) and the
polymerizable compound (A2). The molar ratio of the polymerizable
compound (A1):the polymerizable compound (A2) in the polymerizable
compound (A) is 100:0 to 50. The combination is preferably a
condensation product having a weight average molecular weight of
100 to 100,000 and a polymerizable organic group and being produced
by hydrolyzing the polymerizable compound (A1) and the
polymerizable compound (A2) and by condensing the resultant
hydrolyzed products.
[0082] For hydrolyzing and condensing the organic silicon compound,
there is used water in an amount of more than 1 mole and 100 moles
or less, preferably 1 mole to 50 moles, relative to 1 mole of a
hydrolyzable group (such as a chlorine atom and an alkoxy group) of
the organic silicon compound.
[0083] The production of the polymerizable compound (A) of the
present invention is characterized in that when at least one of
silane compound selected from the above compounds is hydrolyzed and
condensed, a catalyst is used. Examples of the catalyst capable of
being used in this case include a chelate compound of a metal such
as titanium and aluminum, an acid catalyst, and an alkaline
catalyst.
[0084] The silicon atom-containing polymerizable compound (A)
contains the organic silicon compound of Formula (I) or a
combination of the organic silicon compound of Formula (I) and the
organic silicon compound of Formula (III), and is preferably a
polymerizable organic group-having condensation product having a
weight average molecular weight of 100 to 1,000,000 produced by
hydrolyzing an organic silicon compound containing an organic
silicon compound in which the value of a+b or the values of a+b and
a.sup.1+b.sup.1 in the organic silicon compound of Formula (I) or
in both of the organic silicon compound of Formula (I) and the
organic silicon compound of Formula (III) become(s) 1 in a ratio of
5 to 75% by mass and by condensing the resultant hydrolyzed
product.
[0085] The resist underlayer film forming composition of the
present invention is produced ordinarily by dissolving or
dispersing the polymerizable compound (A) in an organic solvent.
The organic solvent is at least one selected from a group
consisting of an alcohol solvent, a ketone solvent, an amide
solvent, an ester solvent, and an aprotic solvent.
[0086] In the resist underlayer film forming composition of the
present invention, there may be further blended a component such as
.beta.-diketone, colloidal silica, colloidal alumina, an organic
polymer, a surfactant, a silane coupling agent, a radical
generator, a triazene compound, and an alkaline compound.
[0087] The organic silicon compound used in the present invention
is hydrolyzed and condensed ordinarily in an organic solvent.
[0088] Examples of the organic solvent used for the hydrolysis
include: aliphatic hydrocarbon solvents such as n-pentane,
isopentane, n-hexane, isohexane, n-heptane, isoheptane,
2,2,4-trimethylpentane, n-octane, isooctane, cyclohexane, and
methylcyclohexane; aromatic hydrocarbon solvents such as benzene,
toluene, xylene, ethylbenzene, trimethylbenzene,
methylethylbenzene, n-propylbenzene, isopropylbenzene,
diethylbenzene, isobutylbenzene, triethylbenzene,
di-isopropylbenzene, n-amylnaphthalene, and trimethylbenzene;
monoalcohol solvents such as methanol, ethanol, n-propanol,
isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol,
n-pentanol, isopentanol, 2-methylbutanol, sec-pentanol,
tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol,
sec-hexanol, 2-ethylbutanol, sec-heptanol, heptanol-3, n-octanol,
2-ethylhexanol, sec-octanol, n-nonyl alcohol,
2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol,
trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl
alcohol, phenol, cyclohexanol, methylcyclohexanol,
3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol,
diacetone alcohol, and cresol;
[0089] polyalcohol solvents such as ethylene glycol, propylene
glycol, 1,3-butylene glycol,
pentanediol-2,4,2-methylpentanediol-2,4,hexanediol-2,5,heptanediol
-2,4,2-ethylhexanediol -1,3,diethylene glycol, dipropylene glycol,
triethylene glycol, tripropylene glycol, and glycerin;
[0090] ketone solvents such as acetone, methyl ethyl ketone,
methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone,
methyl-isobutyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl
ketone, methyl-n-hexyl ketone, di-isobutyl ketone,
trimethylnonanone, cyclohexanone, methylcyclohexanone,
2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone,
and fenchone;
[0091] ether solvents such as ethyl ether, isopropyl ether, n-butyl
ether, n-hexyl ether, 2-ethylhexyl ether, ethylene oxide,
1,2-propylene oxide, dioxolane, 4-methyldioxolane, dioxane,
dimethyldioxane, ethylene glycol monomethyl ether, ethylene glycol
monoethyl ether, ethylene glycol diethyl ether, ethylene glycol
mono-n-butyl ether, ethylene glycol mono-n-hexyl ether, ethylene
glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether,
ethylene glycol dibutyl ether, diethylene glycol monomethyl ether,
diethylene glycol monoethyl ether, diethylene glycol diethyl ether,
diethylene glycol mono-n-butyl ether, diethylene glycol di-n-butyl
ether, diethylene glycol mono-n-hexyl ether, ethoxy triglycol,
tetraethylene glycol di-n-butyl ether, propylene glycol monomethyl
ether, propylene glycol monoethyl ether, propylene glycol
monopropyl ether, propylene glycol monobutyl ether, dipropylene
glycol monomethyl ether, dipropylene glycol monoethyl ether,
dipropylene glycol monopropyl ether, dipropylene glycol monobutyl
ether, tripropylene glycol monomethyl ether, tetrahydrofuran, and
2-methyltetrahydrofuran;
[0092] ester solvents such as diethyl carbonate, methyl acetate,
ethyl acetate, .gamma.-butyrolactone, .gamma.-valerolactone,
n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl
acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate,
3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate,
2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate,
methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate,
ethyl acetoacetate, ethylene glycol monomethyl ether acetate,
ethylene glycol monoethyl ether acetate, diethylene glycol
monomethyl ether acetate, diethylene glycol monoethyl ether
acetate, diethylene glycol mono-n-butyl ether acetate, propylene
glycol monomethyl ether acetate, propylene glycol monoethyl ether
acetate, propylene glycol monopropyl ether acetate, propylene
glycol monobutyl ether acetate, dipropylene glycol monomethyl ether
acetate, dipropylene glycol monoethyl ether acetate, glycol
diacetate, methoxy triglycol acetate, ethyl propionate, n-butyl
propionate, isoamyl propionate, diethyl oxalate, di-n-butyl
oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl
lactate, diethyl malonate, dimethyl phthalate, and diethyl
phthalate;
[0093] nitrogen-containing solvents such as N-methylformamide,
N,N-dimethylformamide, N,N-diethylformamide, acetamide,
N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide, and
N-methylpyrrolidone; and sulfur-containing solvents such as
dimethyl sulfide, diethyl sulfide, thiophene, tetrahydrothiophene,
dimethylsulfoxide, sulfolane, and 1,3-propane sultone.
[0094] Particularly preferred are propylene glycol monomethyl
ether, propylene glycol monoethyl ether, propylene glycol
monopropyl ether, propylene glycol monobutyl ether, propylene
glycol dimethyl ether, propylene glycol diethyl ether, propylene
glycol monomethyl ether acetate, propylene glycol monoethyl ether
acetate, and propylene glycol monopropyl ether acetate, in terms of
preservation solubility of the solution thereof.
[0095] When the organic silicon compound is hydrolyzed and
condensed, a catalyst may be used. Examples of the catalyst used in
this case include a metal chelate compound, an organic acid, an
inorganic acid, an organic base, and an inorganic base. Examples of
the metal chelate compound include: titanium chelate compounds such
as triethoxy.cndot.mono(acetylacetonate)titanium,
tri-n-propoxy.cndot.mono(acetylacetonate)titanium,
tri-isopropoxy.cndot.mono(acetylacetonate)titanium,
tri-n-butoxy.cndot.mono(acetylacetonate)titanium,
tri-sec-butoxy.cndot.mono(acetylacetonate)titanium,
tri-tert-butoxy.cndot.mono(acetylacetonate)titanium,
diethoxy.cndot.bis(acetylacetonate)titanium,
di-n-propoxy.cndot.bis(acetylacetonate)titanium,
di-isopropoxy.cndot.bis(acetylacetonate)titanium,
di-n-butoxy.cndot.bis(acetylacetonate)titanium,
di-sec-butoxy.cndot.bis(acetylacetonate)titanium,
di-Cert-butoxy.cndot.bis(acetylacetonate)titanium,
monoethoxy.cndot.tris(acetylacetonate)titanium,
mono-n-propoxy.cndot.tris(acetylacetonate)titanium,
mono-isopropoxy.cndot.tris(acetylacetonate)titanium,
mono-n-butoxy.cndot.tris(acetylacetonate)titanium,
mono-sec-butoxy.cndot.tris(acetylacetonate)titanium,
mono-tert-butoxy.cndot.tris(acetylacetonate)titanium,
tetrakis(acetylacetonate)titanium,
triethoxy.cndot.mono(ethylacetoacetate)titanium,
tri-n-propoxy.cndot.mono(ethylacetoacetate)titanium,
tri-isopropoxy.cndot.mono(ethylacetoacetate)titanium,
tri-n-butoxy.cndot.mono(ethylacetoacetate)titanium,
tri-sec-butoxy.cndot.mono(ethylacetoacetate)titanium,
tri-tert-butoxy.cndot.mono(ethylacetoacetate)titanium,
diethoxy.cndot.bis(ethylacetoacetate)titanium,
di-n-propoxy.cndot.bis(ethylacetoacetate)titanium,
di-isopropoxy.cndot.bis(ethylacetoacetate)titanium,
di-n-butoxy.cndot.bis(ethylacetoacetate)titanium,
di-sec-butoxy.cndot.bis(ethylacetoacetate)titanium,
di-tert-butoxy.cndot.bis(ethylacetoacetate)titanium,
monoethoxy.cndot.tris(ethylacetoacetate)titanium,
mono-n-propoxy.cndot.tris(ethylacetoacetate)titanium,
mono-isopropoxy.cndot.tris(ethylacetoacetate)titanium,
mono-n-butoxy.cndot.tris(ethylacetoacetate)titanium,
mono-sec-butoxy.cndot.tris(ethylacetoacetate)titanium,
mono-tert-butoxy.cndot.tris(ethylacetoacetate)titanium,
tetrakis(ethylacetoacetate)titanium,
mono(acetylacetonate)tris(ethylacetoacetate)titanium,
bis(acetylacetonate)bis(ethylacetoacetate)titanium, and
tris(acetylacetonate)mono(ethylacetoacetate)titanium;
[0096] zirconium chelate compounds such as
triethoxy.cndot.mono(acetylacetonate)zirconium,
tri-n-propoxy.cndot.mono(acetylacetonate)zirconium,
tri-isopropoxy.cndot.mono(acetylacetonate)zirconium,
tri-n-butoxy.cndot.mono(acetylacetonate)zirconium,
tri-sec-butoxy.cndot.mono(acetylacetonate)zirconium,
tri-tert-butoxy.cndot.mono(acetylacetonate)zirconium,
diethoxy.cndot.bis(acetylacetonate)zirconium,
di-n-propoxy.cndot.bis(acetylacetonate)zirconium,
di-isopropoxy.cndot.bis(acetylacetonate)zirconium,
di-n-butoxy.cndot.bis(acetylacetonate)zirconium,
di-sec-butoxy.cndot.bis(acetylacetonate)zirconium,
di-tert-butoxy.cndot.bis(acetylacetonate)zirconium,
monoethoxy.cndot.tris(acetylacetonate)zirconium,
mono-n-propoxy.cndot.tris(acetylacetonate)zirconium,
mono-isopropoxy.cndot.tris(acetylacetonate)zirconium,
mono-n-butoxy.cndot.tris(acetylacetonate)zirconium,
mono-sec-butoxy.cndot.tris(acetylacetonate)zirconium,
mono-tert-butoxy.cndot.tris(acetylacetonate)zirconium,
tetrakis(acetylacetonate)zirconium,
triethoxy.cndot.mono(ethylacetoacetate)zirconium,
tri-n-propoxy.cndot.mono(ethylacetoacetate)zirconium,
tri-isopropoxy.cndot.mono(ethylacetoacetate)zirconium,
tri-n-butoxy.cndot.mono(ethylacetoacetate)zirconium,
tri-sec-butoxy.cndot.mono(ethylacetoacetate)zirconium,
tri-tert-butoxy.cndot.mono(ethylacetoacetate)zirconium,
diethoxy.cndot.bis(ethylacetoacetate)zirconium,
di-n-propoxy.cndot.bis(ethylacetoacetate)zirconium,
di-isopropoxy.cndot.bis(ethylacetoacetate)zirconium,
di-n-butoxy.cndot.bis(ethylacetoacetate)zirconium,
di-sec-butoxy.cndot.bis(ethylacetoacetate)zirconium,
di-tert-butoxy.cndot.bis(ethylacetoacetate)zirconium,
monoethoxy.cndot.tris(ethylacetoacetate)zirconium,
mono-n-propoxy.cndot.tris(ethylacetoacetate)zirconium,
mono-isopropoxy.cndot.tris(ethylacetoacetate)zirconium,
mono-n-butoxy.cndot.tris(ethylacetoacetate)zirconium,
mono-sec-butoxy.cndot.tris(ethylacetoacetate)zirconium,
mono-tert-butoxy.cndot.tris(ethylacetoacetate)zirconium,
tetrakis(ethylacetoacetate)zirconium,
mono(acetylacetonate)tris(ethylacetoacetate)zirconium,
bis(acetylacetonate)bis(ethylacetoacetate)zirconium, and
tris(acetylacetonate)mono(ethylacetoacetate)zirconium; and aluminum
chelate compounds such as tris(acetylacetonate)aluminum and
tris(ethylacetoacetate)aluminum.
[0097] Examples of the organic acid include acetic acid, propionic
acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid,
octanoic acid, nonanoic acid, decanoic acid, oxalic acid, maleic
acid, methylmalonic acid, adipic acid, sebacic acid, gallic acid,
butyric acid, mellitic acid, arachidonic acid, shikimic acid,
2-ethylhexanoic acid, oleic acid, stearic acid, linolic acid,
linoleic acid, salicylic acid, benzoic acid, p-aminobenzoic acid,
p-toluenesulfonic acid, benzenesulfonic acid, monochloroacetic
acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic
acid, formic acid, malonic acid, sulfonic acid, phthalic acid,
fumaric acid, citric acid, and tartaric acid, Examples of the
inorganic acid include hydrochloric acid, nitric acid, sulfuric
acid, hydrofluoric acid, and phosphoric acid. Examples of the
organic base include pyridine, pyrrole, piperazine, pyrrolidine,
piperidine, picoline, trimethylamine, triethylamine,
monoethanolamine, diethanolamine, dimethylmonoethanolamine,
monomethyldiethanolamine, triethanolamine, diazabicyclo octane,
diazabicyclo nonane, diazabicyclo undecene, and tetramethylammonium
hydroxide. Examples of the inorganic base include ammonia, sodium
hydroxide, potassium hydroxide, barium hydroxide, and calcium
hydroxide. Among these catalysts, metal chelate compounds, organic
acids, and inorganic acids are preferred and more preferred are
titanium chelate compounds and organic acids. These catalysts may
be used individually or in combination of two or more types
thereof.
[0098] Further, for enhancing adhesion to the resist, wettability
with the base substrate, flexibility, planarity, and the like of
the underlayer film, if necessary, polymerizable compounds
containing no silicon atom below may be used to be copolymerized
(hybridization) or mixed with the above silicon atom-containing
polymerizable compounds.
[0099] Specific examples of the ethylenic unsaturated bond-having
polymerizable compound containing no silicon atom include ethylene
glycol di(meth)acrylate, diethylene glycol di(meth)acrylate,
triethylene glycol di(meth)acrylate, tetraethylene glycol
di(meth)acrylate, nonaethylene glycol di(meth)acrylate,
polyethylene glycol di(meth)acrylate, tripropylene glycol
di(meth)acrylate, tetrapropylene glycol di(meth)acrylate,
nonapropylene glycol di(meth)acrylate, polypropylene glycol
di(meth)acrylate, 2,2-bis[4-(acryloxydiethoxy)phenyl]propane,
2,2-bis[4-(methacryloxydiethoxy)phenyl]propane,
3-phenoxy-2-propanoyl acrylate,
1,6-bis(3-acryloxy-2-hydroxypropyl)-hexyl ether, pentaerythritol
tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycerol
tri(meth)acrylate, tris-(2-hydroxyethyl)-isocyanuric acid ester
(meth)acrylate, pentaerythritol tetra(meth)acrylate,
dipentaerythritol penta(meth)acrylate, and dipentaerythritol
hexa(meth)acrylate. Here, ethylene glycol di(meth)acrylate means
ethylene glycol diacrylate and ethylene glycol dimethacrylate.
[0100] Examples of the ethylenic unsaturated bond-having
polymerizable compound containing no silicon atom also include
urethane compounds that can be obtained by a reaction between a
multivalent isocyanate compound and a hydroxyalkyl unsaturated
carboxylic acid ester compound, compounds that can be obtained by a
reaction between a multivalent epoxy compound and a hydroxyalkyl
unsaturated carboxylic acid ester compound, diallyl ester compounds
such as diallyl phthalate, and divinyl compounds such as divinyl
phthalate.
[0101] Examples of the cation polymerizable moiety-having
polymerizable compound containing no silicon atom include a
compound having a cyclic ether structure such as an epoxy ring and
an oxetane ring, a vinyl ether structure, a vinyl thioether
structure, or the like.
[0102] Although the epoxy ring-having polymerizable compound
containing no silicon atom is not particularly limited, as such a
polymerizable compound, a compound having one to six, or two to
four epoxy ring(s) can be used. Examples of the epoxy ring-having
polymerizable compound include compounds having two or more
glycidyl ether structures or glycidyl ester structures that can be
produced from a compound having two or more hydroxy groups or
carboxy groups such as diol compounds, triol compounds,
dicarboxylic acid compounds, and tricarboxylic acid compounds and a
glycidyl compound such as epichlorohydrin.
[0103] Specific examples of the epoxy ring-having polymerizable
compound containing no silicon atom include 1,4-butanediol
diglycidyl ether, 1,2-epoxy-4-(epoxyethyl)cyclohexane, glycerol
triglycidyl ether, diethylene glycol diglycidyl ether,
2,6-diglycidylphenyl glycidyl ether,
1,1,3-tris[p-(2,3-epoxypropoxy)phenyl]propane, 1,2-cyclohexane
dicarboxylic acid diglycidyl ester,
4,4'-methylenebis(N,N-diglycidylaniline),
3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate,
trimethylolethane triglycidyl ether, triglycidyl-p-aminophenol,
tetraglycidyl meta-xylenediamine,
tetraglycidyldiaminodiphenylmethane,
tetraglycidyl-1,3-bisaminomethylcyclohexane, bisphenol-A-diglycidyl
ether, bisphenol-S-diglycidyl ether, pentaerythritol tetraglycidyl
ether, resorcinol diglycidyl ether, phthalic acid diglycidyl ester,
neopentyl glycol diglycidyl ether, polypropylene glycol diglycidyl
ether, tetrabromobisphenol-A-diglycidyl ether,
bisphenolhexafluoroacetone glycidyl ether, pentaerythritol
diglycidyl ether, tris-(2,3-epoxypropyl)isocyanurate, monoallyl
diglycidyl isocyanurate, diglycerol polydiglycidyl ether,
pentaerythritol polyglycidyl ether,
1,4-bis(2,3-epoxypropoxyperfluoroisopropyl)cyclohexane, sorbitol
polyglycidyl ether, trimethylolpropane polyglycidyl ether, resorcin
diglycidyl ether, 1,6-hexanediol diglycidyl ether, polyethylene
glycol diglycidyl ether, phenyl glycidyl ether, p-tert-butylphenyl
glycidyl ether, adipic acid diglycidyl ether, o-phthalic acid
diglycidyl ether, dibromophenyl glycidyl ether,
1,2,7,8-diepoxyoctane, 1,6-dimethylolperfluorohexane diglycidyl
ether, 4,4'-bis(2,3-epoxypropoxyperfluoroisopropyl)diphenyl ether,
2,2-bis(4-glycidyloxyphenyl)propane,
3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexane carboxylate,
3,4-epoxycyclohexyloxirane,
2-(3,4-epoxycyclohexyl)-3',4'-epoxy-1,3-dioxane-5-spirocyclohexane,
1,2-ethylenedioxy-bis(3,4-epoxycyclohexylmethane),
4',5'-epoxy-2'-methylcyclohexylmethyl-4,5-epoxy-2-methylcyclohexane
carboxylate, ethylene glycol-bis(3,4-epoxycyclohexane carboxylate),
bis-(3,4-epoxycyclohexylmethyl)adipate, and
bis(2,3-epoxycyclopentyl) ether.
[0104] Although the oxetane ring-having polymerizable compound
containing no silicon atom is not particularly limited, as such a
polymerizable compound, a compound having one to six, or two to
four oxetane ring(s) can be used.
[0105] Examples of the oxetane ring-having polymerizable compound
containing no silicon atom include 3-ethyl-3-hydroxymethyloxetane,
3-ethyl-3-(phenoxymethyl)oxetane, 3,3-diethyloxetane,
3-ethyl-3-(2-ethylhexyloxymethyl)oxetane,
1,4-bis(((3-ethyl-3-oxetanyl)methoxy)methyl)benzene,
di((3-ethyl-3-oxetanyl)methyl) ether, and
pentaerythritoltetrakis((3-ethyl-3-oxetanyl)methyl) ether.
[0106] Although the vinyl ether structure-having polymerizable
compound containing no silicon atom is not particularly limited, as
such a polymerizable compound, a compound having one to six, or two
to four vinyl ether structure(s) can be used.
[0107] Examples of the vinyl ether structure-having polymerizable
compound containing no silicon atom include vinyl-2-chloroethyl
ether, vinyl-n-butyl ether, 1,4-cyclohexanedimethanol divinyl
ether, vinyl glycidyl ether,
bis(4-(vinyloxymethyl)cyclohexylmethyl) glutarate,
tri(ethyleneglycol) divinyl ether, adipic acid divinyl ester,
diethylene glycol divinyl ether, tris(4-vinyloxy)butyl
trimellirate, bis(4-(vinyloxy)butyl) terephthalate,
bis(4-(vinyloxy)butyl isophthalate, ethylene glycol divinyl ether,
1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether,
tetraethylene glycol divinyl ether, neopentyl glycol divinyl ether,
trimethylolpropane trivinyl ether, trimethylolethane trivinyl
ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether,
tetraethylene glycol divinyl ether, pentaerythritol divinyl ether,
pentaerythritol trivinyl ether, and cyclohexanedimethanol divinyl
ether.
[0108] The polymerization initiator (B) in the underlayer film
forming composition of the present invention is not particularly
limited so long as the polymerization initiator (B) is a
polymerizable compound having an action capable of initiating the
polymerization of the polymerizable compound by heat-baking or
light-irradiation. As the polymerization initiator (B), a compound
generating an acid (a Bronsted acid or a Lewis acid), a base, a
radical, or a cation by light-irradiation or heat-baking can be
used.
[0109] Examples of the polymerization initiator (B) include: a
compound capable of generating an active radical by
light-irradiation to effect radical polymerization of the
polymerizable compound, that is, a photo radical polymerization
initiator; and a compound capable of generating a cation species
such as a protonic acid and a carbon cation by light-irradiation to
effect cation polymerization of the polymerizable compound, that
is, a photo cation polymerization initiator.
[0110] The light-irradiation can be performed using, for example, a
light having a wavelength of 150 nm to 1,000 nm, or 200 to 700 nm,
or 300 to 600 nm. Then, as the photopolymerization initiator, there
is preferably used a photo radical polymerization initiator
generating an active radical or a photo cation polymerization
initiator generating a cation species by an exposure dose of 1 to
2,000 mJ/cm.sup.2, or 10 to 1,500 mJ/cm.sup.2, or 50 to 1,000
mJ/cm.sup.2.
[0111] Examples of the photo radical polymerization initiator
include an imidazole compound, a diazo compound, a bisimidazole
compound, an N-arylglycine compound, an organic azide compound, a
titanocene compound, an aluminate compound, an organic peroxide, an
N-alkoxypyridinium salt compound, and a thioxanthone compound.
[0112] Examples of the azide compound include p-azidebenzaldehyde,
p-azideacetophenone, p-azidebenzoic acid,
p-azidebenzalacetophenone, 4,4'-diazidechalcone,
4,4'-diazidediphenyl sulfide, and
2,6-bis(4'-azidebenzal)-4-methylcyclohexanone.
[0113] Examples of the diazo compound include
1-diazo-2,5-diethoxy-4-p-tolylmercaptobenzene borofluoride,
1-diazo-4-N,N-dimethylaminobenzene chloride, and
1-diazo-4-N,N-diethylaminobenzene borofluoride.
[0114] Examples of the bisimidazole compound include
2,2'-bis(o-chlorophenyl)-4,5,4',5'4etrakis(3,4,5-trimethoxyphenyl)
1,2'-bisimidazole and 2,2'-bis(o-chlorophenyl)
4,5,4',5'-tetraphenyl-1,2'-bisimidazole.
[0115] Examples of the titanocene compound include
dicyclopentadienyl-titanium-dichloride,
dicyclopentadienyl-titanium-bisphenyl,
dicyclopentadienyl-titanium-bis(2,3,4,5,6-pentafluorophenyl),
dicyclopentadienyl-titanium-bis(2,3,5,6-tetrafluorophenyl),
dicyclopentadienyl-titanium-bis(2,4,6-trifluorophenyl),
dicyclopentadienyl-titanium-bis(2,6-difluorophenyl),
dicyclopentadienyl-titanium-bis(2,4-difluorophenyl),
bis(methylcyclopentadienyl)-titanium-bis(2,3,4,5,6-pentafluorophenyl),
bis(methylcyclopentadienyl)-titanium-bis(2,3,5,6-tetrafluorophenyl),
bis(methylcyclopentadienyl)-titanium-bis(2,6-difluorophenyl), and
dicyclopentadienyl-titanium-bis(2,6-difluoro-3-(11-1-pyrrole-1-y0-phenyl)-
.
[0116] Examples of the photo radical polymerization initiator also
include 1,3-di(tert-butyldioxycarbonyl)benzophenone,
3,3',4,4'-tetrakis(tert-butyldioxycarbonyl)benzophenone,
3-phenyl-5-isoxazolone, 2-mercaptobenzimidazole,
2,2-dimethoxy-1,2-diphenylethane-1-one,
1-hydroxy-cyclohexyl-phenyl-ketone, and
2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone.
[0117] Examples of the photo cation polymerization initiator
include sulfonic acid ester, a sulfonimide compound, a
disulfonyldiazomethane compound, a dialkyl-4-hydroxysulfonium salt,
an arylsulfonic acid-p-nitrobenzyl ester, a silanol-aluminum
complex, and (.eta.6-benzene)(.eta.5-cyclopentadienyl)
iron(II).
[0118] Examples of the sulfonimide compound include
N-(trifluoromethanesulfonyloxy)succinimide,
N-(nonafluoro-n-butanesulfonyloxy)succinimide,
N-(camphorsulfonyloxy)succinimide, and
N-(trifluoromethanesulfonyloxy)naphthalimide.
[0119] Examples of the disulfonyldiazomethane compound include
bis(trifluoromethylsulfonyl)diazomethane,
bis(cyclohexylsulfonyl)diazomethane,
bis(phenylsulfonyl)diazomethane,
bis(p-toluenesulfonyl)diazomethane,
bis(2,4-dimethylbenzenesulfonyl)diazomethane, and
methylsulfonyl-p-toluenesulfonyldiazomethane.
[0120] Examples of the photo cation polymerization initiator also
include
2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one.
[0121] An aromatic iodonium salt compound, an aromatic sulfonium
salt compound, an aromatic diazonium salt compound, an aromatic
phosphonium salt compound, a triazine compound, and an iron arene
complex compound can be used both as a photo radical polymerization
initiator and as a photo cation polymerization initiator.
[0122] Examples of the aromatic iodonium salt compound include
diphenyliodoniumhexafluorophosphate,
diphenyliodoniumtrifluoromethanesulfonate,
diphenyliodoniumnonafluoro-n-butanesulfonate,
diphenyliodoniumperfluoro-n-octanesulfonate,
diphenyliodoniumcamphorsulfonate,
bis(4-tert-butylphenyl)iodoniumcamphorsulfonate, and
bis(4-cert-butylphenypiodoniumtrifluoromethanesulfonate.
[0123] Examples of the aromatic sulfonium salt compound include
triphenylsulfoniumhexafluoroantimonate,
triphenylsulfoniumnonafluoro n-butanesulfonate,
triphenylsulfoniumcamphorsulfonate, and
triphenylsulfoniumtrifluoromethanesulfonate.
[0124] In the resist underlayer film forming composition of the
present invention, the photopolymerization initiators may be used
individually or in combination of two or more types thereof.
[0125] Further, as a compound capable of generating a cation or a
radical by heat-baking (heating) to effect a thermopolymerization
reaction of the polymerizable compound, there can be blended in the
composition an acid compound such as p-toluenesulfonic acid,
trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid,
salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, and
hydroxybenzoic acid, or an acid generator such as
2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl
tosylate, bis(4-tert-butylphenyl)iodoniumtrifluoromethane
sulfonate, triphenylsulfoniumtrifluoromethane sulfonate,
phenyl-bis(trichloromethyl)-s-triazine, benzoin tosylate, and
N-hydroxysuccinimidetrifluoromethane sulfonate. The condition for
baking is accordingly selected from the baking temperatures of
60.degree. C. to 300.degree. C. and the baking times of 0.3 to 90
minutes.
[0126] As the contents of the polymerizable compound (A) and the
polymerization initiator (B) in the resist underlayer film forming
composition of the present invention, the content of the
polymerization initiator (B) is, for example, 1 to 20 part(s) by
mass, or 3 to 10 parts by mass, relative to 100 parts by mass of
the polymerizable compound (A). When the content of the
polymerization initiator (B) is less than this amount, the
polymerization reaction is not satisfactorily progressed and the
hardness and the wear resistance of the resultant underlayer film
may become unsatisfactory. When the content of the polymerization
initiator becomes more than this amount, curing is caused only in
the vicinity of the surface of the resist underlayer film, so that
it may become difficult that the inside of the underlayer film is
completely cured. Further, in the case where heat-baking is
applied, when the content of the polymerization initiator becomes
more than this amount, the amount of a sublimated polymerization
initiator increases, which becomes a cause of contamination of the
inside of a baking oven.
[0127] In the resist underlayer film forming composition of the
present invention, when, as the polymerizable compound, a compound
having an ethylenic unsaturated bond that is a radical
polymerizable moiety is used, a photo radical polymerization
initiator is preferably used as the polymerization initiator. When,
as the polymerizable compound, a compound having a vinyl ether
structure, an epoxy ring, or an oxetane ring that is a cation
polymerizable moiety is used, a photo cation polymerization
initiator is preferably used as the polymerization initiator. As
the polymerizable compound for heat-baking, when a compound having
a silanol group is used, triphenylsulfoniumtrifluoromethane
sulfonate and pyridinium p-toluenesulfonic acid are preferably used
as the polymerization initiator.
[0128] In the resist underlayer film forming composition of the
present invention, there may be blended, besides the polymerizable
compound (A) and the polymerization initiator (B), if necessary, a
surfactant, a sensitizer, an amine compound, a polymer compound, an
antioxidant, a thermopolymerization inhibitor, a surface modifier,
a defoaming agent, and the like.
[0129] By blending a surfactant in the resist underlayer film
forming composition, the formation of a pinhole, a striation, and
the like can be suppressed and applicability of the underlayer film
forming composition can be enhanced. Examples of the surfactant
include: a polyoxyethylene alkyl ether compound such as
polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and
polyoxyethylene oleyl ether; a polyoxyethylene alkylallyl ether
compound such as polyoxyethylene octylphenol ether and
polyoxyethylene nonylphenol ether; a
polyoxyethylene-polyoxypropylene block copolymer compound; a
sorbitan fatty acid ester compound such as sorbitan monolaurate,
sorbitan monopalmitate, sorbitan monostearate, sorbitan trioleate,
and sorbitan tristearate; and a polyoxyethylene sorbitan fatty acid
ester compound such as polyoxyethylene sorbitan monolaurate,
polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan
monostearate, and polyoxyethylene sorbitan tristearate. Examples of
the surfactant also include: a fluorinated surfactant such as EFTOP
EF301, EF303, and EF352 (trade name; manufactured by Tohkem.
Products Corp.), MEGAFAC F171, F173, R-08, and R-30 (trade name;
manufactured by Dainippon Ink and Chemicals, Inc.), Fluorad FC430
and FC431 (manufactured by Sumitomo 3M Limited), AsahiGuard AG710
and Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106
(trade name; manufactured by Asahi Glass Co., Ltd.); and
Organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical
Co., Ltd.). When the surfactant is used, the additive amount
thereof is, for example, 0.1 to 5 parts by mass, or 0.5 to 2 parts
by mass, relative to 100 parts by mass of the polymerizable
compound (A).
[0130] The sensitizer can be used for enhancing the sensitivity of
the photopolymerization initiator relative to light. Examples of
the sensitizer include: a pyrromethene complex compound such as
2,6-diethyl-1,3,5,7,8-pentamethylpyrromethene-BF.sub.2 complex and
1,3,5,7,8-pentamethylpyrromethene-BF.sub.2 complex; a
xanthene-based dye such as eosin, ethyleosin, erythrosine,
fluorescein, and rose bengal; a ketothiazoline compound such as
1-(1-methylnaphtho[1,2-d]thiazole-2(1H)-ylidene-4-(2,3,6,7)tetrahydro-1H,-
5H-benzo[ij] quinolizine-9-yl)-3-butene-2-one, and
1-(3-methylbenzothiazole-2(3H)-ylidene-4-(p-dimethylaminophenyl)-3-butene-
-2-one; and a styryl or phenylbutadienyl heterocyclic compound such
as 2-(p-dimethylaminostyryl)-naphtha[1,2-d]thiazole and
2-[4-(p-dimethylaminophenyl)-1,3-butadienyl]-naphtho[1,2-d]thiazole.
Examples of the sensitizer also include
2,4-diphenyl-6-(p-dimethylaminostyryl)-1,3,5-triazine,
2,4-diphenyl-6-(([2,3,6,7]tetrahydro-1
H,5H-benzo[ij]quinolizine-9-yl)-1-ethene-2-yl)-1,3,5-triazonenanthryl-(([-
2,3,6,7]tetrahydro-1H,5H-benzo[ij] quinolizine-9-yl)-1-ethene-2-yl)
ketone, 2,5-bis(p-dimethylaminocinnamylidene)cyclopentanone, and
5,10,15,20 tetraphenylporphyrin. When the sensitizer is used, the
additive amount thereof is, for example, 0.1 to 20 parts by mass,
relative to 100 parts by mass of the polymerizable compound
(A).
[0131] The amine compound can be used for preventing the lowering
of the sensitivity of the photopolymerization initiator due to
oxygen inhibition. As the amine compound, various amine compounds
such as aliphatic amine compounds and aromatic amine compounds can
be used. When the amine compound is used, the additive amount
thereof is, for example, 0.1 to 10 parts by mass, relative to 100
parts by mass of the polymerizable compound (A).
[0132] A polymer compound can be blended in the composition. As the
polymer compound, the type thereof is not particularly limited and
there can be used various polymer compounds having a weight average
molecular weight of around 1,000 to 1,000,000. Examples of the
polymer include an acrylate polymer, a methacrylate polymer, a
novolac polymer, a styrene polymer, a polyamide, a polyamic acid, a
polyester, and a polyimide, that have a benzene ring, a naphthalene
ring, or an anthracene ring. When the polymer compound is used, the
additive amount thereof is, for example, 0.1 to 50 parts by mass,
relative to 100 parts by mass of the polymerizable compound
(A).
[0133] The resist underlayer film forming composition of the
present invention is preferably used in a solution state in which
each component (hereinafter, called "solid content") such as the
polymerizable compound (A) and the polymerization initiator (B) is
dissolved in the solvent (C). The solid content is a component
remaining after subtracting the solvent from all components of the
resist underlayer film forming composition. The solvent can be used
so long as the solvent can dissolve the solid content to prepare a
homogeneous solution. When an organic silicon compound is
hydrolyzed to obtain a condensation product from the resultant
hydrolyzed product and the resultant condensation product is used
as the polymerizable compound (A), an organic solvent used for
hydrolysis of the organic silicon compound as it is preferably used
as the solvent (C) of the resist underlayer film forming
composition.
[0134] Examples of the solvent (C) include ethylene glycol
monomethyl ether, ethylene glycol monoethyl ether, methylcellosolve
acetate, ethylcellosolve acetate, diethylene glycol monomethyl
ether, diethylene glycol monoethyl ether, propylene glycol,
propylene glycol monomethyl ether, propylene glycol monomethyl
ether acetate, propylene glycol propyl ether acetate, toluene,
xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl
2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl
ethoxyacetate, ethyl hydroxyacetate, methyl
2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl
3-methoxypropionate, ethyl 3-ethoxypropionate, methyl
3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate,
butyl acetate, ethyl lactate, butyl lactate, N-dimethylformamide,
N-dimethylacetamide, dimethyl sulfoxide, and
N-methylpyrrolidone.
[0135] These solvents (C) may be used individually or in
combination of two or more types thereof. As the solvent, a solvent
having a boiling point of 80 to 250.degree. C., or 100 to
200.degree. C., or 120 to 180.degree. C. is preferably used. When
the boiling point of the solvent is low, the solvent is evaporated
in a large amount during the application of the resist underlayer
film forming composition to cause an increase of the viscosity of
the composition, so that lowering of the applicability of the
composition may be caused. When the boiling point of the solvent is
high, it is considered that drying of the resist underlayer film
forming composition after the application thereof takes much time.
The solvent can be used in an amount by which the concentration of
the solid content of the resist underlayer film forming composition
becomes, for example, 0.5 to 50% by mass, or 3 to 40% by mass, or
10 to 30% by mass.
[0136] The present invention includes a process of applying the
resist underlayer film forming composition on a substrate to be
processed to form a coating film and a process of performing
light-irradiation, heat-baking, or both of them relative to the
coating film to form an underlayer film, to produce a
semiconductor, a light-emitting diode, a solid-state image pickup
device, a recording apparatus, or a display apparatus.
[0137] The present invention includes a process of applying the
resist underlayer film forming composition of the present invention
on a substrate to be processed to form a resist underlayer film, a
process of performing heat-baking or light-irradiation relative to
the resist underlayer film to cure the resist underlayer film, and
a process of applying a resist composition for nanoimprint on the
resist underlayer film and heat-baking the composition to form a
resist for nanoimprint, so that can form a laminated structure used
for a pattern forming process using nanoimprint.
[0138] Then, the present invention includes a process of applying a
resist underlayer film forming composition on a substrate to form a
resist underlayer film, a process of performing heat-baking,
light-irradiation, or both of them relative to the resist
underlayer film to cure the resist underlayer film, a process of
applying a resist composition for nanoimprint on the resist
underlayer film and heat-baking the resist composition to form a
resist for nanoimprint, and a process of performing imprint by a
step and repeat method, so that can form a laminated structure used
for a pattern forming process using nanoimprint.
[0139] Then, the present invention further includes a process of
imprinting the substrate for a semiconductor, a light-emitting
diode, a solid-state image pickup device, a recording apparatus, or
a display that is coated with the resist underlayer film and the
resist, a process of parting a template (mold) from the resist
after imprinting to obtain a resist pattern without development, a
process of etching the underlayer film according to the resist
pattern, and a process of processing the substrate according to the
patterned photoresist and the patterned underlayer film to produce
a semiconductor, a light-emitting diode, a solid-state image pickup
device, a recording apparatus, or a display apparatus. For the
imprinting, a photo-imprinting method or a thereto-imprinting
method can be used.
[0140] The substrate to be processed is a substrate which has a
hole having an aspect ratio represented by height/diameter of 1 or
more and is used for a semiconductor, a light-emitting diode, a
solid-state image pickup device, a recording apparatus, or a
display apparatus.
[0141] Hereinafter, the use of the underlayer film forming
composition of the present invention is described.
[0142] On a substrate to be processed (such as a silicon/silicon
dioxide-coated substrate, a silicon wafer substrate, a silicon
nitride substrate, a glass substrate, an ITO substrate, a polyimide
substrate, and a low dielectric constant material (low-k
material)-coated substrate) that is used for the production of a
semiconductor, a light-emitting diode, a solid-state image pickup
device, a recording apparatus, or a display apparatus, the resist
underlayer film forming composition of the present invention is
applied by an appropriate coating method such as spinner, coater,
spray, and inkjet to form a coating film. Then, before performing
light-irradiation or heat-baking relative to the coating film, if
necessary, a drying process can be established. When a resist
underlayer film forming composition containing a solvent is used,
the drying process is preferably established.
[0143] The drying process is not particularly limited so long as
the drying process is not by a method of heating at a high
temperature. This is because, it is considered that when the resist
underlayer film forming composition is heated at a high temperature
(for example, a temperature of 300.degree. C. or more), the
sublimation or the like of the solid content contained in the
resist underlayer film is caused, so that an apparatus is
contaminated. The drying process can be performed, for example, by
heating the substrate on a hot plate at 50 to 100.degree. C. for
0.1 to 10 minutes. The drying process can also be performed, for
example, by air-drying the substrate at room temperature (around
20.degree. C.).
[0144] Next, relative to the resist underlayer film, heat-baking,
light-irradiation, or both of them is(are) performed. The method
for the light-irradiation is not particularly limited to be used so
long as the method is a method capable of acting on the
polymerization initiator (B) to effect polymerization of the
polymerizable compound (A). The light-irradiation can be performed,
for example, by using an ultra high pressure mercury lamp, a flash
UV lamp, a high pressure mercury lamp, a low pressure mercury lamp,
a DEEP-UV (deep ultraviolet) lamp, a xenon short arc lamp, a short
arc metal halide lamp, a lamp for YAG laser exciting, a xenon flash
lamp, and the like. The light-irradiation can'be performed, for
example, by using an ultra high pressure mercury lamp and by
irradiating with lights having all wavelengths of around 250 nm to
around 650 nm containing bright line spectra having peaks at
wavelengths of 289 nm, 297 nm, 303 nm, 313 nm (j ray), 334 nm, and
365 nm (i ray) in an ultraviolet region and wavelengths of 405 nm
(h ray), 436 nm (g ray), 546 nm, and 579 nm in a visible light
region.
[0145] By light-irradiation, a cation species or an active radical
is generated from the photopolymerization initiator in the resist
underlayer film, and then, by these species and radical, the
polymerization reaction of the polymerizable compound in the resist
underlayer film is effected. Then, as a result of the
polymerization reaction, the resist underlayer film is formed.
[0146] The thus formed resist underlayer film comes to have a low
solubility in a solvent used for a resist composition for
nanoimprint applied as an upper layer of the resist underlayer
film, such as ethylene glycol monomethyl ether, ethylcellosolve
acetate, diethylene glycol monoethyl ether, propylene glycol,
propylene glycol monomethyl ether, propylene glycol monomethyl
ether acetate, propylene glycol propyl ether acetate, toluene,
methyl ethyl ketone, cyclohexanone, ethyl 2-hydroxypropionate,
ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, methyl
pyruvate, ethyl lactate, and butyl lactate. Therefore, the resist
underlayer film formed from the resist underlayer film forming
composition of the present invention becomes a resist underlayer
film causing no intermixing with the overcoated resist for
nanoimprint.
[0147] The conditions for heat-baking (heating) are accordingly
selected from the baking temperatures of 80.degree. C. to
300.degree. C. and the baking times of 0.3 to 90 minutes.
Preferably, the conditions are the baking temperature of
130.degree. C. to 300.degree. C. and the baking time of 0.5 to 5
minutes.
[0148] The resist underlayer film forming composition of the
present invention can be applied to a substrate having an aspect
ratio represented by height/diameter of 0.01 or more, for example,
having a hole of a diameter of 60 to 100,000 nm, or having an
aspect ratio represented by height/width of 0.01 or more, for
example, having a step of a width of 60 to 100,000 nm.
[0149] Then, the resist underlayer film forming composition of the
present invention can be used for filling such a hole with the
underlayer film without causing a gap (void). In addition, the
underlayer film forming composition of the present invention can be
applied to a substrate to be processed having holes of an aspect
ratio of 0.01 or more coarsely or finely (substrate having a
portion in which holes exist coarsely and a portion in which holes
exist finely). Then, the resist underlayer film forming composition
of the present invention can be used for forming a planar resist
underlayer film on the surface of such a substrate in which holes
exist coarsely or finely.
[0150] The resist underlayer film forming composition of the
present invention can also be applied to a substrate to be
processed which has a hole or step having an aspect ratio of less
than 0.01 and is used for the production of a semiconductor, a
light-emitting diode, a solid-state image pickup device, a
recording apparatus, or a display apparatus. In addition, the
resist underlayer film forming composition of the present invention
can also be applied to a substrate having no step or the like.
[0151] The film thickness of the resist underlayer film formed from
the resist underlayer film forming composition of the present
invention is on the surface of the substrate, for example, 1 to
10,000 nm, or 5 to 10,000 nm, or 5 to 1,000 nm.
[0152] Next, on the resist underlayer film, a resist is formed.
Herewith, on the substrate to be processed used for the production
of a semiconductor, a light-emitting diode, a solid-state image
pickup device, a recording apparatus, or a display apparatus, a
laminated structure of the resist underlayer film and the resist is
formed. The formation of the resist can be performed by an
appropriate known method such as spinner, coater, spray, and
inkjet, that is, by applying a solution of a resist composition on
the resist underlayer film and by performing light-irradiation or
heat-baking relative to the resultant coating. The resist formed on
the resist underlayer film of the present invention is not
particularly limited, and as the resist, any one of an
acrylate-type organic acrylic resist and an inorganic resist that
are used for general purposes can be used. There is disclosed, for
example, a photocurable inorganic resist containing, as the main
component, a siloxane polymer (see Non-patent Document 2), which is
publicly-known. Further, there is disclosed an organic resist using
polyvinyl alcohol (see Non-patent Document 3). There is disclosed a
resist material composition containing a fluorine additive used in
photo nanoimprint lithography. There is disclosed an example using
a photocurable resin and forming a pattern by photo nanoimprint
lithography (Patent Document 8). There is disclosed a resist
curable composition for nanoimprint lithography containing a
polymerizable compound, a photopolymerization initiator, and an
interface active polymerization initiator and having a limited
viscosity (Patent Document 9).
[0153] The pattern forming process by imprint is divided into a
bulk transferring method and a step and repeat method. The bulk
transferring method is a method including: forming a resist film on
the whole surface of the substrate to be processed; and then using
a template having the same size as that of the substrate, pressing
the template against the substrate to transfer a pattern. On the
other hand, the step and repeat method is a method including: using
a template processed into a smaller chip size, performing
repeatedly the transferring per a size of the template as with the
exposure treatment by photolithography; and performing finally the
pattern formation on the whole surface of the substrate by imprint.
Generally, the substrate or the template has warp or unevenness, so
that when the substrate to be processed is large or when the
formation of a fine pattern is necessary, it becomes difficult to
press the template homogeneously and parallel against the substrate
to be processed. From described above, the step and repeat method
is more preferred.
[0154] A pattern forming process by photo-imprint is excellent in
releasing properties between the template (mold) and the resist, in
alignment precision, and in productivity, causes a small amount of
defect and a small amount of the change in the pattern size by
thermal expansion or thermal contraction of the resist, and takes a
short processing time in comparison with a pattern forming process
by thermo-imprint. In terms of the above described superiority of
the pattern forming process by photo-imprint, the pattern forming
process by photo-imprint is suitable for an application requiring a
finer processing.
[0155] The pattern formation is performed by imprint through an
arbitrary template. In the pattern forming process by imprint, the
pattern formation by imprint is performed by: applying the
underlayer film composition of the present invention used as an
underlayer of the resist for nanoimprint on a substrate to be
processed; applying a resist composition for imprint on the
underlayer film as an upper layer thereof; and pressing a light
transmittable template against the resist composition and
performing heat-baking, light-irradiation, or both of them. In the
pattern forming process by photo-imprint, at least one of the
template and the substrate uses a material transmitting an
irradiated light.
[0156] The template has a same-sized pattern to be imprinted.
Although the template can form a pattern according to the desired
processing precision, for example, by photolithography, an electron
beam drawing method, or the like, in the present invention, the
template pattern forming method is not particularly limited.
Although the template applicable to the present invention is not
particularly limited, the template may be a template having a
predetermined strength and durability. Specific examples of the
template include a glass, a quartz, an acrylic resin, a
light-transparent resin such as a polycarbonate resin, a
transparent metal evaporated film, a flexible film such as
polydimethylsiloxane, a photo-cured film, and a metal film.
Particularly, in terms of transparency and quality, a patterned
quartz is preferred.
[0157] The non-light transmitting-type template (mold) material is
not particularly limited so long as it is a material having a
predetermined strength and shape retentivity. Specific examples of
such a material include a ceramic material, an evaporated film, a
magnetic film, a reflecting film, a metal substrate such as Ni, Cu,
Cr, and Fe, and a substrate such as SiC, silicone, nitride
silicone, polysilicone, oxide silicone, and amorphous silicone, to
which the examples are not particularly limited. The shape may be
any one of a plate-shape mold and a roll-shape mold. The roll-shape
mold is applied particularly when continuous productivity of
transferring is necessary.
[0158] With respect to the pattern formation by imprint, the
releasing property between the mold and a cured product of the
resist for photo nanoimprint lithography is important, so that
there is performed an attempt to solve an adhesion problem by using
a mold or surface treatment of a mold, specifically, by using a
hydrogenated silsesqui oxane or a fluorinated ethylene propylene
copolymer mold.
[0159] As the template used in the present invention, it is
preferred to use a template that has been subjected to releasing
treatment by a silane coupling agent such as a silicone-based or
fluorine-based silane coupling agent for enhancing the releasing
property between a cured product of a resist for photo nanoimprint
lithography and the template. For example, a commercially available
mold release agent such as tridecafluoro
1,1,2,2-tetrahydrooctyldimethylsilane and Novec EGC-1720 can also
be preferably used, to which the examples are not particularly
limited.
[0160] Then, using a resist pattern formed by imprint as a
protecting film, the removal of the resist underlayer film of the
present invention and the processing of a semiconductor substrate
are performed. The removal of the resist underlayer film can be
performed by dry etching using a gas such as tetrafluoromethane,
perfluorocyclobutane (C.sub.4F.sub.8), perfluoropropane
(C.sub.3F.sub.8), trifluoromethane, carbon monoxide, argon, oxygen,
nitrogen, sulfur hexafluoride, difluoromethane, nitrogen
trifluoride, and chlorine trifluoride. By the removal of the resist
underlayer film, a pattern containing the resist underlayer film
and the resist is formed on the substrate to be processed.
[0161] The first method using the resist underlayer film formed
from the resist underlayer film forming composition of the present
invention as a hardmask includes a process of applying the resist
underlayer film forming composition of the present invention on a
semiconductor substrate and performing heat-baking,
light-irradiation, or both of them to form a resist underlayer
film, a process of applying a resist composition on the resist
underlayer film to form a resist film, a process of imprinting the
resist film, a process of parting the template from the resist
after imprinting to obtain a resist pattern, a process of etching
the resist underlayer film according to the resist pattern, and a
process of processing the semiconductor substrate according to the
patterned resist and underlayer film, to produce a semiconductor, a
light-emitting diode, a solid-state image pickup device, a
recording apparatus, or a display apparatus. Here, the resist
underlayer film has a large etching rate same as that of the resist
or more under a CF.sub.4 gas condition used during etching of the
resist, so that the resist underlayer film of the present invention
can be removed by etchingaccording to the resist pattern, and using
the resist and the resist underlayer film as protecting films, the
semiconductor substrate can be processed.
[0162] The second method using the resist underlayer film formed
from the resist underlayer film forming composition of the present
invention as a hardmask includes a process of forming an organic
film (a gap filling material or a spin-on carbon material) on a
substrate to be processed by an applying-type organic film forming
composition, a process of applying the resist underlayer film
forming composition of the present invention on the organic film
and performing heat-baking, light-irradiation, or both of them to
form a resist underlayer film, a process of applying a resist
composition on the resist underlayer film to form a resist film, a
process of imprinting the resist film, a process of parting the
template from the resist after imprinting to obtain a resist
pattern, a process of etching the resist underlayer film according
to the resist pattern, and a process of processing the
semiconductor substrate according to the patterned resist and
underlayer film, to produce a semiconductor, a light-emitting
diode, a solid-state image pickup device, a recording apparatus, or
a display apparatus. Here, the resist underlayer film has a large
etching rate same as that of the resist or more under a CF.sub.4
gas condition used during etching of the resist, so that the
underlayer film of the present invention can be removed by
etchingaccording to the resist pattern and the resist pattern can
be transferred to the resist underlayer film of the present
invention. Further, the resist underlayer film has a far smaller
etching rate than that of the organic film (having the same etching
characteristic as that of the resist) under an O.sub.2 (oxygen) gas
condition used during etching of the organic film that is formed
under the present invention. Thus the resist pattern transferred to
the resist underlayer film of the present invention can further be
transferred to the organic film, and using the organic film as a
protecting film, the substrate to be processed can be
processed.
[0163] On a substrate to be processed having unevenness or warp,
the resist underlayer film forming composition of the present
invention can be formed for the purpose of planarization of the
substrate.
[0164] Hereinafter, the present invention will be more specifically
described referring to Examples, which should not be construed as
limiting the scope of the present invention.
EXAMPLES
Example 1
[0165] 45.0 g of 3-glycidoxypropyltrimethoxysilane (manufactured by
Shin-Etsu Chemical Co., Ltd.; trade name: KBM 403), 26.0 g of
monomethyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co.,
Ltd.; trade name: KBM 13), 20.2 g of water, and 0.690 g of
p-toluenesulfonic acid were added to 143.2 g of propylene glycol
monomethyl ether and the resultant mixture was stirred at
80.degree. C. for 24 hours to hydrolyze
3-glycidoxypropyltrimethoxysilane and monomethyltrimethoxysilane
and to obtain a condensation product thereof. The molar ratio of
3-glycidoxypropyltrimethoxysilane and monomethyltrimethoxysilane
was 50%:50%. The obtained polysiloxane resin had a weight average
molecular weight of 1,300 and a number average molecular weight of
1,000.
[0166] Next, to 20.0 g of the reaction solution, 0.0400 g of a
photopolymerization initiator
triphenylsulfoniumtris(trifluoromethylsulfonyl) methanide (Ciba
Japan K. K.; trade name: CGI TPS C1) and 0.0467 g of a surfactant
(manufactured by Dainippon Ink & Chemicals, Inc.; trade name:
MEGAFAC R30) were added and the resultant mixture was mixed with
45.5 g of propylene glycol monomethyl ether and 14.5 g of propylene
glycol monomethyl ether acetate to prepare a 10% by mass solution.
Then, the solution was filtered using a polyethylene microfilter
having a pore diameter of 0.2 .mu.m to prepare a solution of a
resist underlayer film forming composition.
Example 2
[0167] 38.1 g of 3-glycidoxypropyltrimethoxysilane (manufactured by
Shin-Etsu Chemical Co., Ltd.; trade name: KBM 403), 11.0 g of
monomethyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co.,
Ltd.; trade name: KBM 13), 20.0 g of
3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu
Chemical Co., Ltd.; trade name: KBM 503), 17.1 g of water, and
0.583 g of p-toluenesulfonic acid were added to 139.2 g of
propylene glycol monomethyl ether and the resultant mixture was
stirred at 80.degree. C. for 8 hours to hydrolyze
3-glycidoxypropyltrimethoxysilane, monomethyltrimethoxysilane, and
3-methacryloxypropyltrimethoxysilane and to obtain a condensation
product thereof. The molar ratio of
3-glycidoxypropyltrimethoxysilane, monomethyltrimethoxysilane, and
3-methacryloxypropyltrimethoxysilane was 50%:25%:25%. The obtained
polysiloxane resin had a weight average molecular weight of 900 and
a number average molecular weight of 800.
[0168] Next, to 10.0 g of the reaction solution, 0.0200 g of a
photopolymerization initiator
triphenylsulfoniumtris(trifluoromethylsulfonyl) methanide (Ciba
Japan K. K.; trade name: CGI TPS C1) and 0.0233 g of a surfactant
(manufactured by Dainippon Ink & Chemicals, Inc.; trade name:
MEGAFAC R30) were added and the resultant mixture was mixed with
22.7 g of propylene glycol monomethyl ether and 7.24 g of propylene
glycol monomethyl ether acetate to prepare a 10% by mass solution.
Then, the solution was filtered using a polyethylene microfilter
having a pore diameter of 0.2 .mu.m to prepare a solution of an
underlayer film forming composition.
Example 3
[0169] 38.1 g of 3-glycidoxypropyltrimethoxysilane (manufactured by
Shin-Etsu Chemical Co., Ltd.; trade name: KBM 403), 40.0 g of
3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu
Chemical Co., Ltd.; trade name: KBM 503), 17.1 g of water, and
0.583 g of p-toluenesulfonic acid were added to 157.3 g of
propylene glycol monomethyl ether and the resultant mixture was
stirred at 80.degree. C. for 8 hours to hydrolyze
3-glycidoxypropyltrimethoxysilane and
3-methacryloxypropyltrimethoxysilane and to obtain a condensation
product thereof. The molar ratio of
3-glycidoxypropyltrimethoxysilane and
3-methacryloxypropyltrimethoxysilane was 50%:50%. The obtained
polysiloxane resin had a weight average molecular weight of 1,200
and a number average molecular weight of 1,000.
[0170] Next, to 10.0 g of the reaction solution, 0.0200 g of a
photopolymerization initiator
triphenylsulfoniumtris(trifluoromethylsulfonyl) methanide (Ciba
Japan K. K.; trade name: CGI TPS C1) and 0.0233 g of a surfactant
(manufactured by Dainippon Ink & Chemicals, Inc.; trade name:
MEGAFAC R30) were added and the resultant mixture was mixed with
22.7 g of propylene glycol monomethyl ether and 7.24 g of propylene
glycol monomethyl ether acetate to prepare a 10% by mass solution.
Then, the solution was filtered using a polyethylene microfilter
having a pore diameter of 0.2 .mu.m to prepare a solution of an
underlayer film forming composition.
[0171] (Dissolution Test in Resist Solvent)
[0172] Each of the solutions of the resist underlayer film forming
compositions obtained in Example 1 to Example 3 was applied on a
semiconductor substrate (silicon wafer substrate) by a spinner to
form a coating film. The coating film was irradiated with all
wavelengths from a lamp enhanced at 380 nm (manufactured by Ore
Manufacturing Co., Ltd.; metal halide lamp) (exposure dose: 200
ml/cm.sup.2). Then, for removing the solvent and drying the coating
film, the coating film was heated on a hot plate at 130.degree. C.
for 1 minute to form a resist underlayer film (film thickness: 179
nm). Next, the resist underlayer film was immersed in ethyl lactate
and propylene glycol monomethyl ether both of which are solvents
used for a resist for imprint, and butyl acrylate contained in the
resist for imprint used in the present invention. It was confirmed
that the resist underlayer films obtained from the resist
underlayer film forming compositions obtained in Example 1 to
Example 3 were insoluble in these solvents.
[0173] (Measurement of Optical Parameters)
[0174] In the same manner as described above, the resist underlayer
film was formed on a silicon wafer substrate from each of the
solutions of the resist underlayer film forming compositions
obtained in Example 1 to Example 3 in a film thickness described in
Table 1. Then, using a spectro-ellipsometer, the refractive index
(n value) and the attenuation coefficient (k value) at a wavelength
of 633 nm of the underlayer film were measured and these measured
values are shown in Table 1.
[0175] In Table 1, the results of the description "Examples 1 to 3"
mean the result of the evaluation of the resist underlayer films
obtained from the resist underlayer film forming compositions of
Examples 1 to 3.
TABLE-US-00001 TABLE 1 Film thickness Refractive index Attenuation
coefficient (nm) (n value) (k value) Example 1 179 1.50 0.0003
Example 2 185 1.49 0.0002 Example 3 171 1.50 0.0004
[0176] (Test of Dry Etching Rate)
[0177] In the same manner as described above, the resist underlayer
film was formed on a silicon wafer substrate from each of the
solutions of the resist underlayer film forming compositions
obtained in Example 1 to Example 3 in a film thickness described in
Table 2. Then, using an RIE system ES401 (manufactured by Nippon
Scientific Co., Ltd.) and under a condition of using O.sub.2 and
CF.sub.4 as a dry etching gas, the dry etching rate (loss amount of
film thickness per unit time) of the underlayer film was measured.
The obtained result is shown as selectivity of the dry etching
rate. The ratio of the dry etching rate of the underlayer film when
the dry etching rate of a photoresist for KrF laser lithography
(manufactured by Shin-Etsu Chemical Co., Ltd.; trade name: SEPR
430) under the same conditions is assumed to be 1.00, is the
selection ratio of the dry etching rate.
[0178] In Table 2, the results of the description "Examples 1 to 3"
mean the result of the evaluation of the resist underlayer films
obtained from the resist underlayer film forming compositions of
Examples 1 to 3.
TABLE-US-00002 TABLE 2 Film thickness O.sub.2 gas selection
CF.sub.4 gas selection (nm) ratio ratio Example 1 179 0 1.5 Example
2 185 0 1.5 Example 3 171 0 1.5
[0179] (Preparation of Photocurable Resist for Imprint)
[0180] 11.7 g of butyl acrylate (manufactured by Tokyo Chemical
Industry Co., Ltd.), 20.0 g of isobomyl acrylate (manufactured by
Tokyo Chemical Industry Co., Ltd.), 9.52 g of ethylene glycol
dimethacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.),
and 0.788 g of 2-hydroxy-2-methyl-1-phenyl-propane-1-one
(manufactured by Ciba Japan K. K.; trade name: DAROCUR 1173) were
mixed and the resultant mixture was stirred at room temperature for
5 hours. The molar ratio of butyl acrylate, isobornyl acrylate,
ethylene glycol dimethacrylate, and
2-hydroxy-2-methyl-1-phenyl-propane-1-one was 38%:40%:20%:2%.
[0181] (Photonanoimprint Test)
[0182] In the nanoimprint test of the resist underlayer film of the
present invention, a step and repeat method by a photonanoimprint
apparatus (manufactured by Molecular Imprints, Inc.; trade name:
IMPRIO) was used. From each of the solutions of the resist
underlayer film forming compositions obtained in Examples 1 to 3, a
resist underlayer film (film thickness: 50 nm) was formed on a
silicon wafer substrate. Liquid drops of the photocurable resist
for imprint in an amount of 0.00784 .mu.L per one position were
applied on the resist underlayer film at a total of 49 positions
(7.times.7) in an area of 2.5.times.2.5 cm.sup.2 by a drop applying
method. The substrate to be processed on which liquid drops of the
resist material were applied was placed parallel to a quartz
template in which 80 nm lines were carved with the same interval so
that the distance between the substrate and the template was
homogeneous. At a rate of from 0.4 mm/sec to 0.003 mm/sec, the
distance was reduced to lower the position of the template toward
the substrate to be processed. After the template started to be
contacted with the resist surface, a load was applied to the
template with a pressing pressure of 1.0 to 1.5 N to adhere
completely a convexo-concave portion of the template to the
substrate. Then, the substrate with the template was subjected to
light-irradiation (for 20 seconds) to photo-cure the resist for
imprint. The position of the template was elevated to complete the
forming process of the resist pattern by photonanoimprint.
[0183] The imprinting by forming a resist film in the same manner
as described above directly on a silicon substrate without using a
resist underlayer film forming composition was performed as
Comparative Example 1.
[0184] In Table 3, the results of the description "Examples 1 to 3"
mean the results of evaluating the photoimprint using the resist
underlayer films obtained from the resist underlayer film forming
compositions of Examples 1 to 3. Comparative Example 1 is a result
of evaluating the photoimprint without using the resist underlayer
film forming composition.
[0185] The result of the nanoimprint evaluation (80 nm line, the
ratio of line:space was 1:1) is shown in Table 3.
[0186] The evaluation result 1 indicates rectangularity of the
resist pattern. In the evaluation of the cross sectional shape of
the resist by an SEM observation, (advantageous) indicates a result
in which an angle formed by a resist side wall and the surface of
the resist underlayer film was 80 to 100.degree., and (failure)
indicates a result in which the above angle was less than
80.degree. or 101.degree. or more.
[0187] The evaluation result 2 indicates curing properties of the
resist that was confirmed by the above-described dissolution test
in a resist solvent. (advantageous) indicates a result in which
when the substrate was immersed in ethyl lactate and propylene
glycol monoethyl ether, the difference in the film thickness of the
resist between before and after the immersion was 1 nm or less.
(failure) indicates a result in which the difference in the film
thickness of the resist between before and after the immersion was
1 nm or more and the resist pattern shape disappeared in the
solvent after the immersion.
[0188] The evaluation result 3 indicates fluidity (film-remaining
property) of the resist on the resist underlayer film. In the cross
sectional shape evaluation of the resist by the SEM observation,
(advantageous) indicates a result in which the resist spread
homogeneously into the size of the template, and further,
film-remaining of the resist was homogeneous. (pass) indicates a
result in which although film-remaining of the resist had
unevenness, the resist spread homogeneously into the size of the
template. (failure) indicates a result in which the resist did not
spread homogeneously into the size of the template.
[0189] The evaluation 4 indicates peeling properties of the resist
from the template. (advantageous) indicates a result in which the
resist did not adhere to the template and the pattern forming
succeeded, and (failure) indicates a result in which a part of the
resist adhered to the template and the pattern on the substrate was
peeled.
TABLE-US-00003 TABLE 3 Evaluation result l Evaluation result 2
Evaluation result 3 Evaluation result 4 Example 1 Advantageous
Advantageous Pass Advantageous Example 2 Advantageous Advantageous
Advantageous Advantageous Example 3 Advantageous Advantageous
Advantageous Advantageous Comparative Advantageous Advantageous
Pass Failure Example 1
[0190] On the resist underlayer films obtained from the
compositions for forming the resist underlayer film for nanoimprint
of Examples 1 to 3, the resist did not adhere to the template and a
pattern of 80 nm line (ratio of line:space was 1:1) could be
homogeneously produced in an area of 2.5.times.2.5 cm.sup.2.
[0191] Particularly, when the resist underlayer films obtained from
the compositions for forming the resist underlayer film for
nanoimprint of Examples 2 and 3 were used, the resist liquid drop
could more easily spread before the light-irradiation by the
imprint process and the resist underlayer films were excellent in
resist fluidity (film-remaining property). On the other hand, after
the light-irradiation, the interaction of the resist underlayer
film with the resist was improved, so that it is considered that
the mold-releasing property of the resist from the template became
the best.
[0192] This is because, when the resist underlayer film obtained
from the composition for forming the resist underlayer film for
nanoimprint of Example 2 was used, the composition for forming the
resist underlayer film for nanoimprint of Example 2 is a
composition for forming the resist underlayer film for nanoimprint
by which the contact angle with water that was 67.degree. before
the light-irradiation after the film-formation of the resist
underlayer film was reduced to 63.degree. after the
light-irradiation (with a lamp enhanced at 380 nm (manufactured by
Ore Manufacturing Co., Ltd.; metal halide lamp), exposure dose: 2
J/cm.sup.2).
[0193] In addition, when the resist underlayer film obtained from
the composition for forming the resist underlayer film for
nanoimprint of Example 3 was used, the composition for forming the
resist underlayer film for nanoimprint of Example 3 is a
composition for forming the resist underlayer film for nanoimprint
by which the contact angle measured by a contact angle meter (DM;
manufactured by Kyowa Interface Science Co., Ltd.) with water that
was 71.degree. before the light-irradiation after the
film-formation of the resist underlayer film was reduced to
58.degree. after the light-irradiation (with a lamp enhanced at 380
nm (manufactured by Ore Manufacturing Co., Ltd.; metal halide
lamp), exposure dose: 2 J/cm.sup.2).
[0194] As reference data, with the composition for forming the
resist underlayer film for nanoimprint of Example 1, the contact
angle with water that was 67.degree. before the light-irradiation
was maintained at 67.degree. after the light-irradiation (with a
lamp enhanced at 380 nm (manufactured by Ore Manufacturing Co.,
Ltd.; metal halide lamp), exposure dose: 2 J/cm.sup.2). It is
therefore considered that there appeared a difference between the
evaluation result 3 and the evaluation result 4.
[0195] On the other hand, when the resist was, as Comparative
Example 1, applied directly on a silicon wafer substrate without
using the composition for forming the resist underlayer film for
nanoimprint and imprinted, a pattern of 80 nm line (ratio of
line:space was 1:1) was partly adhered to the template and could
not be homogeneously produced on an area of 2.5.times.2.5
cm.sup.2.
* * * * *