U.S. patent application number 09/572975 was filed with the patent office on 2002-08-22 for acid-decomposable ester compound suitable for use in resist material.
Invention is credited to Hasegawa, Koji, Hatakeyama, Jun, Kinsho, Takeshi, Nakashima, Mutsuo, Nishi, Tsunehiro, Watanabe, Takeru.
Application Number | 20020115874 09/572975 |
Document ID | / |
Family ID | 15213729 |
Filed Date | 2002-08-22 |
United States Patent
Application |
20020115874 |
Kind Code |
A1 |
Kinsho, Takeshi ; et
al. |
August 22, 2002 |
ACID-DECOMPOSABLE ESTER COMPOUND SUITABLE FOR USE IN RESIST
MATERIAL
Abstract
A novel ester compound having an exo-form
2-alkylbicyclo[2.2.1]heptan-2-yl ester as the acid-decomposable
site is used as a dissolution regulator to formulate a resist
composition having a high sensitivity, resolution, etching
resistance and storage stability.
Inventors: |
Kinsho, Takeshi;
(Nakakubiki-gun, JP) ; Nishi, Tsunehiro;
(Nakakubiki-gun, JP) ; Watanabe, Takeru;
(Nakakubiki-gun, JP) ; Hasegawa, Koji;
(Nakakubiki-gun, JP) ; Nakashima, Mutsuo;
(Nakakubiki-gun, JP) ; Hatakeyama, Jun;
(Nakakubiki-gun, JP) |
Correspondence
Address: |
MILLEN, WHITE, ZELANO & BRANIGAN, P.C.
2200 CLARENDON BLVD.
SUITE 1400
ARLINGTON
VA
22201
US
|
Family ID: |
15213729 |
Appl. No.: |
09/572975 |
Filed: |
May 18, 2000 |
Current U.S.
Class: |
552/549 |
Current CPC
Class: |
C07C 2603/74 20170501;
C07C 69/013 20130101; C07C 2602/42 20170501; G03F 7/038 20130101;
C07C 69/753 20130101; G03F 7/0045 20130101; G03F 7/039 20130101;
C07C 2603/68 20170501 |
Class at
Publication: |
552/549 |
International
Class: |
C07J 009/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 19, 1999 |
JP |
11-138090 |
Claims
1. An ester compound of the following general formula (1):
10wherein R.sup.1 is an n-valent hydrocarbon group of 4 to 40
carbon atoms having a saturated alicyclic structure or aromatic
ring structure which may contain a hetero atom; R.sup.2 is a
straight, branched or cyclic alkyl group of 1 to 8 carbon atoms or
a substituted or unsubstituted aryl group of 6 to 20 carbon atoms;
R.sup.3 to R.sup.12 each are hydrogen or a monovalent hydrocarbon
group of 1 to 15 carbon atoms which may contain a hetero atom and
R.sup.3 to R.sup.12, taken together, may form a ring, and when they
form a ring, they represent divalent hydrocarbon groups of 1 to 15
carbon atoms which may contain a hetero atom, or two of R.sup.3 to
R.sup.12 which are attached to adjacent carbon atoms may directly
bond together to form a double bond; and n is an integer of 1 to 8,
with the proviso that the formula also represents an
enantiomer.
2. The ester compound of claim 1 wherein in formula (1), R.sup.1 is
an n-valent hydrocarbon group of 4 to 40 carbon atoms, in which n
hydrogen atoms at arbitrary positions are eliminated to introduce
valence bonds, selected from among (i) alicyclic saturated
hydrocarbons including 11(ii) hydrocarbons belonging to (i) in
which at least one hydrogen atom at an arbitrary position is
replaced by a straight, branched or cyclic alkyl, (iii)
hydrocarbons belonging to (i) and (ii) in which a carbon-carbon
bond at an arbitrary position is unsaturated to introduce at least
one aromatic ring, (iv) hydrocarbons belonging to (i) to (iii) in
which at least one CH.sub.2, CH or C at an arbitrary position is
replaced by O, N, NH, S, SO or SO.sub.2, and (v) hydrocarbons
belonging to (i) to (iv) in which at least one hydrogen atom at an
arbitrary position is replaced by a group of atoms selected from
among a halogen atom, hydroxyl, alkoxy, aryloxy, formyl,
alkylcarbonyl, arylcarbonyl, carboxy, alkoxycarbonyl,
aryloxycarbonyl, cyano, amino, alkylamino, arylamino, mercapto,
alkylthio, arylthio, carbamoyl, alkylcarbamoyl, arylcarbamoyl,
alkylcarbonylamino, arylcarbonylamino, sulfo, oxo, and imino group
or an alkyl or aryl containing said group of atoms, R.sup.2 is a
straight, branched or cyclic alkyl group of 1 to 8 carbon atoms or
an aryl group of 6 to 20 carbon atoms which may be substituted with
an alkyl group, R.sup.3 to R.sup.12 are independently hydrogen, or
straight, branched or cyclic alkyl groups of 1 to 15 carbon atoms
which may be substituted with a group of atoms selected from among
a halogen atom, hydroxyl, alkoxy, aryloxy, formyl, alkylcarbonyl,
arylcarbonyl, carboxy, alkoxycarbonyl, aryloxycarbonyl, cyano,
amino, alkylamino, arylamino, mercapto, alkylthio, arylthio,
carbamoyl, alkylcarbamoyl, arylcarbamoyl, alkylcarbonylamino,
arylcarbonylamino, sulfo, oxo, and imino group, a pair of R.sup.3
and R.sup.4, a pair of R.sup.3 and R.sup.5, a pair of R.sup.4 and
R.sup.6, a pair of R.sup.5 and R.sup.6, a pair of R.sup.5 and
R.sup.7, a pair of R.sup.5 and R.sup.10, a pair of R.sup.5 and
R.sup.11, a pair of R.sup.6 and R.sup.8, a pair of R.sup.6 and
R.sup.11, a pair of R.sup.7 and R.sup.8, a pair of R.sup.7 and
R.sup.9, a pair of R.sup.7 and R.sup.11, a pair of R.sup.8 and
R.sup.11, a pair of R.sup.9 and R.sup.10, a pair of R.sup.9 and
R.sup.11, and a pair of R.sup.10 and R.sup.11 each may form a ring,
and when they form a ring, they are independently straight,
branched or cyclic alkylene groups of 1 to 15 carbon atoms which
may be substituted with a group of atoms selected from among a
halogen atom, hydroxyl, alkoxy, aryloxy, formyl, alkylcarbonyl,
arylcarbonyl, carboxy, alkoxycarbonyl, aryloxycarbonyl, cyano,
amino, alkylamino, arylamino, mercapto, alkylthio, arylthio,
carbamoyl, alkylcarbamoyl, arylcarbamoyl, alkylcarbonylamino,
arylcarbonylamino, sulfo, oxo, and imino group, or a pair of
R.sup.3 and R.sup.5, a pair of R.sup.5 and R.sup.11, a pair of
R.sup.7 and R.sup.11, and a pair of R.sup.9 and R.sup.11 may form a
single bond so that a double bond is formed between the carbon and
the carbon to which these R's are attached.
3. The ester compound of claim 1 or 2 which is used in a resist
material.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a novel acid-decomposable
ester compound suitable for use in a resist material.
[0003] 2. Prior Art
[0004] While a number of recent efforts are being made to achieve a
finer pattern rule in the drive for higher integration and
operating speeds in LSI devices, deep-ultraviolet lithography is
thought to hold particular promise as the next generation in
microfabrication technology. In particular, photolithography using
a KrF or ArF excimer laser as the light source is strongly desired
to reach the practical level as the micropatterning technique
capable of achieving a feature size of 0.3 .mu.m or less.
[0005] For resist materials for use with KrF excimer lasers,
polyhydroxystyrene having a practical level of transmittance and
etching resistance is, in fact, a standard base resin. For resist
materials for use with ArF excimer lasers, polyacrylic or
polymethacrylic acid derivatives and polymers comprising aliphatic
cyclic compounds in the backbone are under investigation. In either
case, the basic concept is that some or all of alkali soluble sites
of alkali soluble resin are protected with suitable
acid-eliminatable groups. The overall performance of resist
material is adjusted by a choice from among a variety of
acid-eliminatable protective groups or by incorporating one or more
low-molecular-weight components having an appropriate function
separate from the resin.
[0006] One typical functional low-molecular-weight component to be
formulated in resist materials is a class of compounds known as
dissolution regulators. A variety of proposals have been made on
the structure of dissolution regulators. A common structure has on
a mother nucleus of a certain size one or plural readily
alkali-soluble sites, some or all of which are blocked with
acid-decomposable protective groups (see JP-A 6-266109 and JP-A
9-278699). When an appropriate amount of dissolution regulator is
blended, the dissolution of the resist film in the unexposed area
is restrained whereas in the exposed area, readily alkali-soluble
sites which are exposed under the action of generated acid promote
the dissolution of the resist film. That is, the differential
dissolution rate between the exposed and unexposed areas is
enhanced. Consequently, the resolution of the resist film is
considerably improved.
[0007] What is required for the dissolution regulator is to keep
low the dissolution rate of the resist film in the unexposed area
and to allow the exposed area to quickly turn to be readily soluble
in an alkali developer. These properties are largely affected by
the mother nucleus and the choice of acid-decomposable sites. For
the mother nucleus, sufficient hydrophobicity is essential for
exerting dissolution inhibition in the unexposed area, and the
mother nucleus must also have such a structure that developer
affinity is insured in deblocked form for exerting dissolution
promotion in the exposed area. Also, the acid-decomposable sites
are required to have contradictory properties in that the
acid-decomposable sites must have a high reactivity sufficient to
quickly decompose even in low exposed area such as resist film deep
inside, whereas they must have a low reactivity sufficient to
prevent reaction from being triggered merely by exposure and a
stability sufficient to prevent a sensitivity variation during
storage, in order to restrain the formation of volatile
decomposition products which can contaminate the optical system of
an aligner. As to the mother nucleus, it is relatively easy to
design the mother nucleus having hydrophobicity and developer
affinity upon deblocking adequate to the purpose, by increasing the
molecular weight above a certain level and optionally incorporating
a cyclic structure. However, the acid-decomposable sites that fully
satisfy the requirement are not yet available.
[0008] As to the currently available acid-decomposable sites,
tertiary alkyl esters such as tert-butyl esters and 1-alkoxyalkyl
esters such as 2-tetrahydropyranyl esters and 1-ethoxyethyl esters
are known as the protected carboxylic acid; tertiary alkyl
carbonates such as tert-butyl carbonate, tertiary alkyl ethers such
as tert-butyl ethers, and 1-alkoxyalkyl ethers such as
2-tetrahydropyranyl ethers and 1-ethoxyethyl ethers are known as
the protected phenolic hydroxyl group. Among the foregoing
examples, however, the 1-alkoxyalkyl esters and 1-alkoxyalkyl
ethers are excessively reactive and have the risk of causing
contamination of the aligner optical system and sensitivity
variation. Inversely, the remaining examples are poorly reactive
and fail to fully accelerate the dissolution rate in the exposed
area. In addition, many other proposals have been made on the
acid-decomposable sites although they are not satisfactory in both
reactivity and stability. While the pattern rule is increasingly
scaled down, there is a need to have a dissolution regulator having
improved acid-decomposable sites and a high sensitivity, high
resolution resist material which can be realized thereby.
SUMMARY OF THE INVENTION
[0009] Therefore, an object of the present invention is to provide
a novel acid-decomposable ester compound which has both high
reactivity and sufficient storage stability and which when blended
as a dissolution regulator, form a resist material having high
sensitivity and resolution.
[0010] It has been found that an ester compound of the following
general formula (1) obtained by a method to be described later is
useful as a dissolution regulator to be blended in a resist
material. The resist material having the ester compound blended
therein has high sensitivity and resolution and is suited for
precise microfabrication.
[0011] The invention provides an ester compound of the following
general formula (1). 1
[0012] Herein R.sup.1 is an n-valent hydrocarbon group of 4 to 40
carbon atoms having a saturated alicyclic structure or aromatic
ring structure which may contain a hetero atom. R.sup.2 is a
straight, branched or cyclic alkyl group of 1 to 8 carbon atoms or
a substituted or unsubstituted aryl group of 6 to 20 carbon atoms.
R.sup.3 to R.sup.12 each are hydrogen or a monovalent hydrocarbon
group of 1 to 15 carbon atoms which may contain a hetero atom and
R.sup.3 to R.sup.2, taken together, may form a ring, and when they
form a ring, they represent divalent hydrocarbon groups of 1 to 15
carbon atoms which may contain a hetero atom, or two of R.sup.3 to
R.sup.12 which are attached to adjacent carbon atoms may directly
bond together to form a double bond. The letter n is an integer of
1 to 8. The formula also represents an enantiomer.
[0013] Preferably in formula (1), R.sup.1 is an n-valent
hydrocarbon group of 4 to 40 carbon atoms, in which n hydrogen
atoms at arbitrary positions are eliminated to introduce valence
bonds, selected from among (i) alicyclic saturated hydrocarbons
including 2
[0014] (ii) hydrocarbons belonging to (i) in which at least one
hydrogen atom at an arbitrary position is replaced by a straight,
branched or cyclic alkyl, (iii) hydrocarbons belonging to (i) and
(ii) in which a carbon-carbon bond at an arbitrary position is
unsaturated to introduce at least one aromatic ring, (iv)
hydrocarbons belonging to (i) to (iii) in which at least one
CH.sub.2, CH or C at an arbitrary position is replaced by O, N, NH,
S, SO or SO.sub.2, and (v) hydrocarbons belonging to (i) to (iv) in
which at least one hydrogen atom at an arbitrary position is
replaced by a group of atoms selected from among a halogen atom,
hydroxyl, alkoxy, aryloxy, formyl, alkylcarbonyl, arylcarbonyl,
carboxy, alkoxycarbonyl, aryloxycarbonyl, cyano, amino, alkylamino,
arylamino, mercapto, alkylthio, arylthio, carbamoyl,
alkylcarbamoyl, arylcarbamoyl, alkylcarbonylamino,
arylcarbonylamino, sulfo, oxo, and imino group or an alkyl or aryl
containing said group of atoms;
[0015] R.sup.2 is a straight, branched or cyclic alkyl group of 1
to 8 carbon atoms or an aryl group of 6 to 20 carbon atoms which
may be substituted with an alkyl group;
[0016] R.sup.3 to R.sup.12 are independently hydrogen, or straight,
branched or cyclic alkyl groups of 1 to 15 carbon atoms which may
be substituted with a group of atoms selected from among a halogen
atom, hydroxyl, alkoxy, aryloxy, formyl, alkylcarbonyl,
arylcarbonyl, carboxy, alkoxycarbonyl, aryloxycarbonyl, cyano,
amino, alkylamino, arylamino, mercapto, alkylthio, arylthio,
carbamoyl, alkylcarbamoyl, arylcarbamoyl, alkylcarbonylamino,
arylcarbonylamino, sulfo, oxo, and imino group, a pair of R.sup.3
and R.sup.4, a pair of R.sup.3 and R.sup.5, a pair of R.sup.4 and
R.sup.6, a pair of R.sup.5 and R.sup.6, a pair of R.sup.5 and
R.sup.7, a pair of R.sup.5 and R.sup.10, a pair of R.sup.5 and
R.sup.11, a pair of R.sup.6 and R.sup.8, a pair of R.sup.6 and
R.sup.11, a pair of R.sup.7 and R.sup.8 a pair of R.sup.7 and
R.sup.9, a pair of R.sup.7 and R.sup.11, a pair of R.sup.8 and
R.sup.11, a pair of R.sup.9 and R.sup.10, a pair of R.sup.9 and
R.sup.11, and a pair of R.sup.10 and R.sup.11 each may form a ring,
and when these R's form a ring, they are independently straight,
branched or cyclic alkylene groups of 1 to 15 carbon atoms which
may be substituted with a group of atoms selected from among a
halogen atom, hydroxyl, alkoxy, aryloxy, formyl, alkylcarbonyl,
arylcarbonyl, carboxy, alkoxycarbonyl, aryloxycarbonyl, cyano,
amino, alkylamino, arylamino, mercapto, alkylthio, arylthio,
carbamoyl, alkylcarbamoyl, arylcarbamoyl, alkylcarbonylamino,
arylcarbonylamino, sulfo, oxo, and imino group, or a pair of
R.sup.3 and R.sup.5, a pair of R.sup.5 and R.sup.11, a pair of
R.sup.7 and R.sup.11, and a pair of R.sup.9 and R.sup.11 may form a
single bond so that a double bond is formed between the carbon and
the carbon to which these R's are attached.
[0017] The ester compound of formula (1) employs an exo-form
2-alkylbicyclo[2.2.1]heptan-2-yl ester or derivative thereof as the
acid-decomposable site, thereby overcoming the problems including
the tert-butyl esters, tert-butyl carbonate and tert-butyl ethers
having low reactivity as well as the 2-tetrahydropyranyl esters,
1-ethoxyethyl esters, 2-tetrahydropyranyl ethers and 1-ethoxyethyl
ethers having excessive reactivity, when used as a dissolution
regulator in a resist material.
[0018] The ester compounds of formula (1) are broadly classified as
alkylcycloalkyl esters. The alkylcycloalkyl esters being basically
tertiary alkyl esters are free of the drawback of excessive
acidolysis; when formulated into resist materials, they do not
allow reaction from taking place merely by exposure to form
volatile decomposition products within the aligner or undergo
decomposition during storage; nevertheless, they have higher
acidolysis than simple tertiary alkyl esters such as tert-butyl
esters. For these reasons, the alkylcycloalkyl esters belong to a
relatively satisfactory class of acid-decomposable sites on the
dissolution regulator for use in resist materials. The ester
compounds of formula (1) for use in resist materials are successful
in significantly enhancing acidolysis without compromising the
advantages of the alkylcycloalkyl esters. The reason is given
below.
[0019] Decomposition reaction of tertiary alkyl esters under acidic
conditions proceeds by way of E1 mechanism. Those esters having a
more stable carbocation under transition conditions have a higher
rate of reaction and hence, a higher rate of decomposition. In the
exo-form 2-alkylbicyclo[2.2.1]heptan-2-yl esters of formula (1),
probably because of .sigma.-participation, a very stable cation is
formed as shown by the reaction scheme below, and thus the progress
of reaction is very rapid. This is a reaction inherent to the
exo-form compound of formula (1). Little or no reaction occurs with
an isomer or an endo-form compound of the following formula (1').
The compounds of formulae (1) and (1'), which look alike when
expressed in plan structure, have largely different rates of acid
decomposition reaction. Accordingly, the compound of formula (1),
the compound of formula (1'), and the compound of formula (1")
expressed with no stereostructure taken into account must be
recognized, in fact, to be completely different substances (see Y.
Yukawa Ed., Theory of Organic Chemistry -Reaction-, Kagaku Dojin
Publishing, 1974, Chap. 3
[0020] Herein, R.sup.1 to R.sup.12 and n are as defined above
although R.sup.3 to R.sup.12 and n are omitted for the brevity of
description.
[0021] Because of the above-described mechanism, the exo-form
2-alkylbicyclo[2.2.1]heptan-2-yl esters of formula (1) have an acid
decomposition ability that outstandingly surpasses not only simple
tertiary alkyl esters, but also alkylcycloalkyl esters and prior
art fused ring-containing alkylcycloalkyl esters having not
considered stereochemistry. Therefore, the resist composition
comprising the inventive compound as a dissolution regulator
becomes a very high sensitivity, high resolution resist material as
compared with prior art resist materials, as will be later
demonstrated in Examples.
[0022] Although the compounds of formula (1) have been arrived at
originally from efforts in pursuit of acid decomposition, quite
unexpectedly, they have some advantages in addition to high
reactivity. Such advantages are a large polarity change due to the
high hydrophobic nature of an eliminatable portion of the acid
eliminatable site, and a very high rigidity that
bicyclo[2.2.1]heptane skeleton possesses. Because of these
excellent characteristics, the resist material having blended
therein the ester compound of the invention has a very high etching
resistance as well as a high sensitivity and high resolution.
[0023] The ester compounds of formula (1) have been arrived at by
making investigations on acid elimination reaction from the aspect
of stereochemistry. In this sense, the present invention is based
on a concept utterly different from the prior art improvement in
acid eliminatable sites that was discussed solely from the
standpoint of plane structure. The invention is clearly
distinguishable from the prior art proposals of novel acid
eliminatable sites.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The ester compound of the invention is of the general
formula (1). 4
[0025] R.sup.1 is an n-valent C.sub.4-40 hydrocarbon group having a
saturated alicyclic structure or aromatic ring structure which may
contain a hetero atom wherein n is an integer of 1 to 8.
[0026] More illustratively, R.sup.1 is an n-valent C.sub.4-40
hydrocarbon group, in which n hydrogen atoms at arbitrary positions
are eliminated to introduce valence bonds, selected from among (i)
alicyclic saturated hydrocarbons including 5
[0027] (ii) hydrocarbons belonging to (i) in which at least one
hydrogen atom at an arbitrary position is replaced by a straight,
branched or cyclic alkyl, preferably of 1 to 20 carbon atoms,
especially 1 to 10 carbon atoms, (iii) hydrocarbons belonging to
(i) and (ii) in which a carbon-carbon bond at an arbitrary position
is unsaturated to introduce at least one aromatic ring, (iv)
hydrocarbons belonging to (i) to (iii) in which at least one
CH.sub.2, CH or C at an arbitrary position is replaced by O, N, NH,
S, SO or S.sub.2, and (v) hydrocarbons belonging to (i) to (iv) in
which at least one hydrogen atom at an arbitrary position is
replaced by a group of atoms (shown below) inclusive of a hetero
atom (e.g., oxygen, nitrogen, sulfur and halogen) or an alkyl or
aryl containing such a group of atoms.
[0028] As the group of atoms inclusive of a hetero atom, mention
may be made of halogen atoms such as fluorine, chlorine and
bromine, hydroxyl groups, alkoxy groups such as methoxy, ethoxy,
butoxy and tert-butoxy, aryloxy groups such as phenyloxy, formyl
groups, alkylcarbonyl groups such as methylcarbonyl and
tert-butylcarbonyl, arylcarbonyl groups such as phenylcarbonyl,
carboxy groups, alkoxycarbonyl groups such as methoxycarbonyl and
tert-butoxycarbonyl, aryloxycarbonyl groups such as
phenyloxycarbonyl, cyano groups, amino groups, alkylamino groups
such as methylamino and dimethylamino, arylamino groups such as
phenylamino and diphenylamino, mercapto groups, alkylthio groups
such as methylthio, arylthio groups such as phenylthio, carbamoyl
groups, alkylcarbamoyl groups such as dimethylcarbamoyl,
arylcarbamoyl groups such as diphenylcarbamoyl, alkylcarbonylamino
groups such as methylcarbonylamino, arylcarbonylamino groups such
as phenylcarbonylamino, sulfo groups, oxo groups, and imino groups.
Also included are alkyl groups such as methyl, ethyl and butyl and
aryl groups such as phenyl, which contain any of the foregoing
groups of atoms.
[0029] The group represented by R.sup.1 has 4 to 40 carbon atoms,
preferably 6 to 35 carbon atoms, and more preferably 8 to 30 carbon
atoms as a whole.
[0030] R.sup.2 is a straight, branched or cyclic C.sub.1-8 alkyl
group or a C.sub.6-20 aryl group which may be substituted with an
alkyl group. Illustrative examples of the straight, branched or
cyclic alkyl group include methyl, ethyl, propyl, isopropyl,
n-butyl, sec-butyl, tert-butyl, tert-amyl, n-pentyl, n-hexyl,
cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl,
cyclohexylmethyl, and cyclohexylethyl. Illustrative examples of the
unsubstituted or alkyl-substituted aryl group include phenyl,
methylphenyl, naphthyl, anthryl, phenanthryl, and pyrenyl.
[0031] R.sup.3 to R.sup.12 are independently hydrogen, or straight,
branched or cyclic C.sub.1-15 alkyl groups which may be substituted
with a group of atoms selected from among a halogen atom, hydroxyl,
alkoxy, aryloxy, formyl, alkylcarbonyl, arylcarbonyl, carboxy,
alkoxycarbonyl, aryloxycarbonyl, cyano, amino, alkylamino,
arylamino, mercapto, alkylthio, arylthio, carbamoyl,
alkylcarbamoyl, arylcarbamoyl, alkylcarbonylamino,
arylcarbonylamino, sulfo, oxo, and imino group. A pair of R.sup.3
and R.sup.4, a pair of R.sup.3 and R.sup.5, a pair of R.sup.4 and
R.sup.6, a pair of R.sup.5 and R.sup.6, a pair of R.sup.5 and
R.sup.7, a pair of R.sup.5 and R.sup.10, a pair of R.sup.5 and
R.sup.11, a pair of R.sup.6 and R.sup.8, a pair of R.sup.6 and
R.sup.11, a pair of R.sup.7 and R.sup.8, a pair of R.sup.7 and
R.sup.9, a pair of R.sup.7 and R.sup.11, a pair of R.sup.8 and
R.sup.11, a pair of R.sup.9 and R.sup.10, a pair of R.sup.9 and
R.sup.11, and a pair of R.sup.10 and R.sup.11 each may form a ring.
When these R's in pair form a ring, they are independently
straight, branched or cyclic C.sub.1-15 alkylene groups which may
be substituted with a group of atoms selected from among a halogen
atom, hydroxyl, alkoxy, aryloxy, formyl, alkylcarbonyl,
arylcarbonyl, carboxy, alkoxycarbonyl, aryloxycarbonyl, cyano,
amino, alkylamino, arylamino, mercapto, alkylthio, arylthio,
carbamoyl, alkylcarbamoyl, arylcarbamoyl, alkylcarbonylamino,
arylcarbonylamino, sulfo, oxo, and imino group. A pair of R.sup.3
and R.sup.5, a pair of R.sup.5 and R.sup.11, a pair of R.sup.7 and
R.sup.11, and a pair of R.sup.9 and R.sup.11 may form a single bond
so that a double bond is formed between the carbon and the carbon
to which these R's are attached.
[0032] Examples of the group of atoms are the same as described for
R.sup.1.
[0033] In formula (1), n is an integer of 1 to 8, and preferably 1
to 6. Further preferably, n is equal to 1, 2, 3 or 4.
[0034] Illustrative examples of the ester compound according to the
invention are those shown below as well as those shown in Examples
though not limited thereto. 6
[0035] The ester compounds of the invention can be prepared, for
example, by the following procedure although the invention is not
limited thereto. 7
[0036] Herein, R.sup.1 to R.sup.12 and n are as defined above
although R.sup.3 to R.sup.12 and n are omitted for the brevity of
description. R.sup.2' is identical with R.sup.2 except that one
hydrogen atom is eliminated from the carbon at the bond position. M
represents a metal, HX an acid, OH a base, [O] an oxidizing agent,
and [H] a reducing agent.
[0037] The first step is to effect nucleophilic addition reaction
to the carbonyl of a bicyclo[2.2.1]heptan-2-one or derivative
thereof to convert it into an endo-form alcohol. Illustrative of
this step are Grignard reaction and reaction using organic lithium
compounds although the reaction involved in this step is not
limited thereto. Reaction readily takes place under well-known
conditions. Reaction is preferably carried out by mixing the
reactants: a ketone compound and an alkyl halide or aryl halide
with the metal M such as magnesium or lithium in a solvent such as
tetrahydrofuran or diethyl ether and heating or cooling the
reaction mixture if desired.
[0038] It is noted that only the endo-form alcohol yields from the
first step and that the following isomerization step is essential
to obtain an exo-form alcohol from which the end exo-form ester is
produced.
[0039] The second step is to convert the endo-form alcohol from the
first step into an exo-form alcohol. Some illustrative,
non-limiting, procedures of the second step include (a)
substitution reaction accompanied by stereo-inversion using acid
HX, followed by alkali hydrolysis or alkali solvolysis; (b)
dehydration, and addition of acid HX to the resulting olefin,
followed by alkali hydrolysis or alkali solvolysis; and (c)
dehydration and epoxidization of the resulting olefin, followed by
reductive cleavage of epoxy. Reaction readily takes place under
well-known conditions. Illustrative, non-limiting examples of the
acid HX include inorganic acids such as hydrochloric acid, aqueous
hydrochloric acid, hydrobromic acid, hydroiodic acid, and sulfuric
acid, and organic acids such as formic acid, acetic acid, propionic
acid, benzoic acid, chloroformic acid, chloroacetic acid,
dichloroacetic acid, trichloroacetic acid, fluoroacetic acid,
difluoroacetic acid, trifluoroacetic acid, and
3,3,3-trifluoropropionic acid. Illustrative, non-limiting examples
of the base OH.sup.- include inorganic hydroxides such as sodium
hydroxide, lithium hydroxide, potassium hydroxide, and barium
hydroxide, inorganic carbonates such as sodium carbonate, sodium
hydrogen carbonate, lithium carbonate, and potassium carbonate, and
alkoxides such as sodium methoxide, sodium ethoxide, lithium
methoxide, lithium ethoxide, lithium tert-butoxide, and potassium
tert-butoxide, and organic bases such as diethylamine,
triethylamine, tri-n-butylamine and dimethylaniline. Illustrative,
non-limiting examples of the oxidizing agent [O] include peracids
such as performic acid, peracetic acid, trifluoroperacetic acid,
and m-chloroperbenzoic acid, and peroxides such as hydrogen
peroxide, dimethyl dioxirane, and tert-butyl hydroperoxide. It is
noted that when reaction is effected using the oxidizing agent, a
metal salt may be co-present as a catalyst. Illustrative,
non-limiting examples of the reducing agent [H] include metal
hydrides such as boran, alkylboran, dialkylboran, dialkylsilane,
trialkylsilane, sodium hydride, lithium hydride, potassium hydride,
and calcium hydride; complex hydride salts such as lithium boron
hydride, sodium boron hydride, calcium boron hydride, lithium
aluminum hydride, and sodium aluminum hydride; alkoxy complex
hydride salts such as lithium trimethoxyaluminum hydride, lithium
diethoxyaluminum hydride, lithium tri-tert-butoxyaluminum hydride,
RED-AL, and sodium trimethoxyborohydride; and alkyl complex hydride
salts such as lithium triethylborohydride, K-Selectride, and
L-Selectride.
[0040] The third step is to esterify the exo-form alcohol. Reaction
readily takes place under well-known conditions. Reaction is
preferably carried out by successively or simultaneously adding the
reactants: the exo-form alcohol, a carboxylic acid halide prepared
separately, and a base (e.g., triethylamine) in a solvent such as
methylene chloride and cooling the reaction mixture if desired.
[0041] It is noted that in the third step, R.sup.1--(COOH).sub.n
instead of R.sup.1-(COCl).sub.n may be reacted in the presence of a
dehydrating agent such as dicyclohexylcarbodiimide.
[0042] The ester compound of the invention is advantageously used
as one component, especially a dissolution regulator in a resist
material. The resist material to which the inventive compound is
applicable may be either positive working or negative working or
even positive and negative working. A chemical amplification resist
material, especially chemical amplification positive resist
material is very useful. The resist material in which the ester
compound of the invention is blended may have any well-known
composition, typically a composition comprising a base resin, a
photoacid generator (i.e., a compound capable of generating an acid
upon exposure to high energy radiation or electron beams), and an
organic solvent.
[0043] The resist material having the ester compound of the
invention blended therein lends itself to micropatterning with
electron beams or deep-UV rays since it is sensitive to high-energy
radiation and has excellent sensitivity, resolution, etching
resistance, and storage stability. Especially because of the
minimized absorption at the exposure wavelength of an ArF or KrF
excimer laser, a finely defined pattern having sidewalls
perpendicular to the substrate can easily be formed.
EXAMPLE
[0044] Examples of the invention are given below by way of
illustration and not by way of limitation.
[0045] Ester compounds within the scope of the invention are
synthesized by the following procedure.
Example 1
Synthesis of DRR1
[0046] In 600 ml of tetrahydrofuran was dissolved 148.5 g of ethyl
bromide. Below 60.degree. C., this reaction mixture was added
dropwise to 32.4 g of metallic magnesium over one hour. After
agitation was continued for 2 hours at room temperature, 110.2 g of
bicyclo[2.2.1]heptan-2-one was added dropwise over 45 minutes to
the reaction mixture which was kept below 65.degree. C. After
agitation was continued for one hour at room temperature, the
reaction solution was worked up in a conventional manner. The
resulting oily substance was distilled in vacuum, collecting 126.9
g of 2-ethylbicyclo[2.2.1]heptan-2-ol in endo-form. The yield was
90.5%.
[0047] In 600 ml of benzene was dissolved 125.0 g of
2-ethylbicyclo[2.2.1]heptan-2-ol in endo-form. To the solution was
added 8.5 g of p-toluenesulfonic acid monohydrate. This reaction
mixture was heated, agitated under reflux for 6 hours while
removing water, and subjected to conventional post-treatment. The
resulting oily substance was purified by silica gel column
chromatography, obtaining 85.9 g of
2-ethylidenebicyclo[2.2.1]heptane. The yield was 78.8%.
[0048] In 500 ml of methylene chloride was dissolved 84.0 g of
2-ethylidenebicyclo[2.2.1]heptane. To this solution was added 219.0
g of 65% m-chloroperbenzoic acid. This reaction mixture was
agitated for 12 hours at 4.degree. C. and subjected to conventional
post-treatment, obtaining an oily substance. This was used in the
subsequent reaction without purification.
[0049] The oily substance obtained in the above step was dissolved
in 200 ml of diethyl ether. With stirring, this solution was added
dropwise to a suspension of 26.2 g of aluminum lithium hydride in
200 ml of diethyl ether under ice cooling. The reaction mixture was
agitated for a further 2 hours at room temperature and subjected to
conventional post-treatment. The resulting oily substance was
distilled in vacuum, obtaining 87.0 g of
2-ethyl-bicyclo[2.2.1]heptan-2-ol in exo-form. The yield was
90.3%.
[0050] In 200 ml of methylene chloride was dissolved 35.0 g of
2-ethylbicyclo[2.2.1]heptan-2-ol in exo-form. With stirring, 47.0 g
of norbornane-2-carboxylic acid chloride and then 54.4 g of
triethylamine were added dropwise to the solution under ice
cooling. The reaction mixture was agitated for a further 12 hours
at room temperature and subjected to conventional post-treatment.
The resulting oily substance was distilled in vacuum, collecting
54.9 g of 2-ethylbicyclo[2.2.1]heptan- -2-yl
norbornane-2-carboxylate in exo-form, designated DRR1. The yield
was 83.3%.
[0051] .sup.1H-NMR (270 MHz): d=0.80 (3H, t), 1.00-2.05 (17H, m),
2.05-2.65 (6H, m)
[0052] IR: n=2962, 2871, 1724, 1187, 1168, 1132, 1114 cm.sup.-1
Example 2
Synthesis of DRR2
[0053] As above, 2-ethylbicyclo[2.2.1]heptan-2-yl
1-adamantanecarboxylate in exo-form, designated DRR2, was
synthesized from bicyclo[2.2.2]heptan-2-one.
[0054] .sup.1H-NMR (270 MHz): d=0.78 (3H, t), 1.05 (1H, m), 1.18
(1H, m), 1.25-1.60 (4H, m), 1.60-2.05 (18H, m), 2.10-2.30 (2H, m),
2.54 (1H, m)
[0055] IR (KBr): n=2964, 2933, 2906, 2850, 1716, 1452, 1325, 1267,
1223, 1221, 1174, 1103, 1078 cm.sup.-1
Example 3
Synthesis of DRR3
[0056] As above, 8-methyltricyclo[5.2.1.0.sup.2.6]decan-8-yl
1-adamantanecarboxylate in exo-form, designated DRR3, was
synthesized from tricyclo[5.2.1.0.sup.2.6]decan-8-one.
[0057] .sup.1H-NMR (270 MHz): d=0.79 (3H, d), 0.85-1.45 (6H, m),
1.60-2.05 (23H, m), 2.16 (1H, dq), 2.34 (1H, m)
[0058] IR (KBr): n=2935, 2904, 2852, 1716, 1452, 1326, 1267, 1236,
1234, 1211, 1161, 1103, 1076 cm.sup.-1
Example 4
Synthesis of DRR4
[0059] As above, 2-ethylbicyclo[2.2.1]heptan-2-yl cholate in
exo-form, designated DRR4, was synthesized from
bicyclo[2.2.1]heptan-2-one.
[0060] .sup.1H-NMR (270 MHz): d=0.66 (3H, s), 0.80 (3H, t), 0.87
(3H, s), 0.90-2.05 (35H, m), 2.05-2.35 (6H, m), 2.51 (1H, m), 3.42
(1H, m), 3.81 (1H, m), 3.95 (1H, m)
[0061] IR (KBr): n=3435, 2964, 2937, 2870, 1726, 1464, 1377, 1329,
1311, 1267, 1223, 1194, 1171, 1078, 1045 cm.sup.-1
Example 5
Synthesis of DRR5
[0062] As above, 2-ethylbicyclo[2.2.1]heptan-2-yl triformylcholate
in exo-form, designated DRR5, was synthesized from
bicyclo[2.2.1]heptan-2-on- e.
[0063] .sup.1H-NMR (270 MHz): d=0.74 (3H, s), 0.81 (3H, t), 0.93
(3H, s), 1.00-2.30 (38H, m), 2.50 (1H, m), 4.70 (1H, m), 5.06 (1H,
m), 5.25 (1H, m), 8.01 (1H, s), 8.09 (1H, s), 8.14 (1H, s)
[0064] IR (KBr): n=2964, 2875, 1720, 1465, 1378, 1250, 1248, 1182
cm.sup.-1
Example 6
Synthesis of DRR6
[0065] As above, 2-ethylbicyclo[2.2.1]heptan-2-yl
1-adamantaneacetate in exo-form, designated DRR6, was synthesized
from bicyclo[2.2.1]heptan-2-on- e.
[0066] .sup.1H-NMR (270 MHz): d=0.82 (3H, t), 1.05 (1H, m), 1.20
(1H, m), 1.30-1.80 (18H, m), 1.90-2.05 (6H, m), 2.21 (1H, m), 2.28
(1H, dq), 2.50 (1H, m)
[0067] IR (KBr): n=2964, 2902, 2848, 1722, 1454, 1328, 1261, 1197,
1174, 1130, 1101 cm.sup.-1
Examples 7-14
Synthesis of DRR7-14
[0068] DRR7 to DRR14 were synthesized by the same procedure as
above. 8
Reference Examples and Comparative Reference Examples
[0069] The ester compounds DRR1 to DRR14 obtained in the above
Examples were formulated into resist materials, whose performance
was examined. For comparison purposes, a similar resist material
without the ester compound was formulated and examined.
[0070] The components used herein were a polymer (Polymer 1 to
Polymer 12), a photoacid generator (PAG1 to PAG8), a dissolution
regulator (DRR15 to DRR18), a compound having a =C--COOH group in
the molecule (ACC1 and ACC2), and a solvent, which were selected in
the combination shown in Tables 1 to 5. The solvent contained 0.05%
by weight of surfactant Florade FC-430 (Sumitomo 3M).
[0071] The solvents and basic compounds used are as follows.
[0072] PGMEA: propylene glycol methyl ether acetate
[0073] PG/EL: a mixture of 70% PGMEA and 30% ethyl lactate
[0074] TBA: tributylamine
[0075] TEA: triethanolamine
[0076] TMMEA: trismethoxymethoxyethylamine
[0077] TMEMEA: trismethoxyethoxymethoxyethylamine 9
Reference Examples I-1 to I-35
[0078] Resist materials were formulated in accordance with the
formulation shown in Tables 1 and 2. These materials were each
filtered through a 0.2-.mu.m Teflon filter, thereby giving resist
solutions. These resist solutions were spin-coated onto silicon
wafers, then baked at 110.degree. C. for 90 seconds on a hot plate
to give resist films having a thickness of 0.5 .mu.m. The resist
films were exposed using an ArF excimer laser stepper (Nikon
Corporation; NA 0.55), then baked (PEB) at 110.degree. C. for 90
seconds, and developed with a solution of 2.38% tetramethylammonium
hydroxide in water, thereby giving positive patterns.
[0079] The resulting resist patterns were evaluated as described
below. First, the sensitivity (mJ/cm.sup.2) was determined as the
dose which provides a 1:1 resolution at the top and bottom of a
0.25 .mu.m line-and-space pattern. The resolution of the resist
under evaluation was defined as the minimum line width (.mu.m) of
the lines and spaces that separated at this dose. The shape of the
resolved resist pattern was examined under a scanning electron
microscope.
[0080] The composition and test results of the resist materials are
shown in Tables 1 and 2.
1TABLE 1 Reference Photoacid Dissolution Basic Sensi- Resolu-
Example Resin generator regulator compound Solvent tivity tion
shape I-1 Polymer 1 PAG 1(2) DRR 1(16) TBA PGMEA 31.2 0.18
rectangular (64) (0.125) (480) I-2 Polymer 1 PAG 1(2) DRR 2(16) TBA
PGMEA 31.8 0.18 rectangular (64) (0.125) (480) I-3 Polymer 1 PAG
1(2) DRR 3(16) TBA PGMEA 32.1 0.18 rectangular (64) (0.125) (480)
I-4 Polymer 1 PAG 1(2) DRR 4(16) TBA PGMEA 34.5 0.18 rectangular
(64) (0.125) (480) I-5 Polymer 1 PAG 1(2) DRR 5(16) TBA PGMEA 32.4
0.18 rectangular (64) (0.125) (480) I-6 Polymer 1 PAG 1(2) DRR
6(16) TBA PGMEA 32.4 0.18 rectangular (64) (0.125) (480) I-7
Polymer 1 PAG 1(2) DRR 7(16) TBA PGMEA 32.1 0.18 rectangular (64)
(0.125) (480) I-8 Polymer 1 PAG 1(2) DRR 8(16) TBA PGMEA 31.8 0.18
rectangular (64) (0.125) (480) I-9 Polymer 1 PAG 1(2) DRR 9(16) TBA
PGMEA 33.0 0.18 rectangular (64) (0.125) (480) I-10 Polymer 1 PAG
1(2) DRR 10(16) TBA PGMEA 32.4 0.18 rectangular (64) (0.125) (480)
I-11 Polymer 1 PAG 1(2) DRR 11(16) TBA PGMEA 30.6 0.18 rectangular
(64) (0.125) (480) I-12 Polymer 3 PAG 1(2) DRR 2(16) TBA PG/EL 30.6
0.18 rectangular (64) (0.125) (480) I-13 Polymer 3 PAG 2(2) DRR
2(16) TBA PG/EL 17.1 0.18 rectangular (64) (0.125) (480) I-14
Polymer 3 PAG 3(2) DRR 2(16) TBA PG/EL 29.7 0.18 rectangular (64)
(0.125) (480) I-15 Polymer 3 PAG 4(2) DRR 2(16) TBA PG/EL 29.3 0.18
rectangular (64) (0.125) (480) I-16 Polymer 3 PAG 5(2) DRR 2(16)
TBA PG/EL 27.9 0.18 rectangular (64) (0.125) (480) I-17 Polymer 3
PAG 6(2) DRR 2(16) TBA PG/EL 28.4 0.18 rectangular (64) (0.125)
(480) I-18 Polymer 3 PAG 7(2) DRR 2(16) TBA PG/EL 18.0 0.18
rectangular (64) (0.125) (480) I-19 Polymer 3 PAG 8(2) DRR 2(16)
TBA PG/EL 15.8 0.18 rectangular (64) (0.125) (480) I-20 Polymer 2
PAG 2(2) DRR 7(16) TBA PGMEA 12.0 0.18 rectangular (32) (0.125)
(480) Polymer 4 (32)
[0081]
2TABLE 2 Reference Photoacid Dissolution Basic Sensi- Resolu-
Example Resin generator regulator compound Solvent tivity tion
shape I-21 Polymer 2 PAG 2(2) DRR 7(16) TEA PGMEA 11.4 0.15
rectangular (32) (0.125) (480) Polymer 4 (32) I-22 Polymer 2 PAG
2(2) DRR 7(16) TMMEA PGMEA 10.8 0.18 rectangular (32) (0.125) (480)
Polymer 4 (32) I-23 Polymer 2 PAG 2(2) DRR 7(16) TMEMEA PGMEA 10.5
0.18 rectangular (32) (0.125) (480) Polymer 4 (32) I-24 Polymer 5
PAG 7(2) DRR 4(4) TEA PGMEA 34.5 0.20 T-top (76) (0.125) (480) I-25
Polymer 5 PAG 7(2) DRR 4(8) TEA PGMEA 33.6 0.18 slight T-top (72)
(0.125) (480) I-26 Polymer 5 PAG 7(2) DRR 4(16) TEA PGMEA 31.5 0.15
rectangular (64) (0.125) (480) I-27 Polymer 5 PAG 7(2) DRR 4(24)
TEA PGMEA 30.9 0.18 rectangular (56) (0.125) (480) I-28 Polymer 6
PAG 8(2) DRR 5(8) TEA PGMEA 13.5 0.20 some positive (64) DRR 15(8)
(0.125) (480) taper I-29 Polymer 6 PAG 8(2) DRR 5(8) TEA PGMEA 14.4
0.20 some positive (64) DRR 16(8) (0.125) (480) taper I-30 Polymer
6 PAG 8(2) DRR 5(8) TEA PGMEA 12.9 0.20 some positive (64) DRR
17(8) (0.125) (480) taper I-31 Polymer 6 PAG 8(2) DRR 5(8) TEA
PGMEA 10.8 0.18 rectangular (64) DRR 18(8) (0.125) (480) I-32
Polymer 7 PAG 2(2) DRR 5(16) TEA PGMEA 18.0 0.18 rectangular (64)
(0.125) (480) I-33 Polymer 7 PAG 2(2) DRR 5(16) TEA PGMEA 17.4 0.15
rectangular (64) ACC 1(4) (0.125) (480) I-34 Polymer 8 PAG 2(2) DRR
5(8) TEA PGMEA 19.5 0.18 rectangular (64) DRR 1(8) (0.125) (480)
I-35 Polymer 8 PAG 2(2) DRR 5(8) TEA PGMEA 18.9 0.18 rectangular
(64) DRR 2(8) (0.125) (480)
Comparative Reference Examples I-1 to I-4
[0082] Resist materials were similarly formulated accordance with
the formulation shown in Table 3 and examined for performance. The
composition and test results of the resist materials are shown in
Table 3.
3TABLE 3 Comparative Reference Photoacid Dissolution Basic Sensi-
Resolu- Example Resin generator regulator compound Solvent tivity
tion shape I-1 Polymer 1 PAG 1(2) DRR 15(16) TBA PGMEA 44.5 0.22
positive taper (64) (0.125) (480) I-2 Polymer 1 PAG 1(2) DRR 16(16)
TBA PGMEA 47.3 0.22 positive taper (64) (0.125) (480) I-3 Polymer 1
PAG 1(2) DRR 17(16) TBA PGMEA 43.1 0.22 positive taper (64) (0.125)
(480) I-4 Polymer 1 PAG 1(2) DRR 18(16) TBA PGMEA 37.7 0.20
rectangular (64) (0.125) (480)
Reference Examples II-1 to II-20
[0083] Resist materials were formulated in accordance with the
formulation shown in Table 4. These materials were each filtered
through a 0.2-.mu.m Teflon filter, thereby giving resist solutions.
These resist solutions were spin-coated onto silicon wafers, then
baked at 110.degree. C. for 90 seconds on a hot plate to give
resist films having a thickness of 0.7 .mu.m. The resist films were
exposed using a KrF excimer laser stepper (Nikon Corporation; NA
0.5), then baked (PEB) at 110.degree. C. for 90 seconds, and
developed with a solution of 2.38% tetramethylammonium hydroxide in
water, thereby giving positive patterns.
[0084] The resulting resist patterns were evaluated as described
below. First, the sensitivity (mJ/cm.sup.2) was determined as the
dose which provides a 1:1 resolution at the top and bottom of a
0.30 .mu.m line-and-space pattern. The resolution of the resist
under evaluation was defined as the minimum line width (.mu.m) of
the lines and spaces that separated at this dose. The shape of the
resolved resist pattern was examined under a scanning electron
microscope.
[0085] The composition and test results of the resist materials are
shown in Table 4.
4TABLE 4 Comparative Reference Photoacid Dissolution Basic Sensi-
Resolu- Example Resin generator regulator compound Solvent tivity
tion shape II-1 Polymer 9 PAG 1(2) DRR 12(16) TEA PG/EL 42.3 0.22
rectangular (64) (0.125) (480) II-2 Polymer 9 PAG 1(2) DRR 13(16)
TEA PG/EL 40.1 0.22 rectangular (64) (0.125) (480) II-3 Polymer 9
PAG 1(2) DRR 14(16) TEA PG/EL 38.5 0.22 rectangular (64) (0.125)
(480) II-4 Polymer 9 PAG 2(2) DRR 13(16) TEA PG/EL 32.3 0.22
rectangular (64) (0.125) (480) II-5 Polymer 10 PAG 2(2) DRR 13(16)
TEA PG/EL 33.5 0.22 rectangular (64) (0.125) (480) II-6 Polymer 11
PAG 2(2) DRR 13(16) TEA PG/EL 30.7 0.20 rectangular (64) (0.125)
(480) II-7 Polymer 12 PAG 2(2) DRR 13(16) TEA PG/EL 31.2 0.22
rectangular (64) (0.125) (480) II-8 Polymer 10 PAG 4(2) DRR 14(4)
TEA PGMEA 45.4 0.26 T-top (76) (0.125) (480) II-9 Polymer 10 PAG
4(2) DRR 14(8) TEA PGMEA 43.7 0.24 slight T- (72) (0.125) (480) top
II-10 Polymer 10 PAG 4(2) DRR 14(16) TEA PGMEA 41.2 0.22
rectangular (64) (0.125) (480) II-11 Polymer 10 PAG 4(2) DRR 14(24)
TEA PGMEA 40.7 0.22 rectangular (56) (0.125) (480) II-12 Polymer 9
PAG 5(2) DRR 13(16) TEA PGMEA 42.7 0.22 rectangular (64) (0.125)
(480) II-13 Polymer 9 PAG 5(2) DRR 13(8) TEA PGMEA 43.3 0.22
rectangular (64) DRR 12(8) (0.125) (480) II-14 Polymer 9 PAG 5(2)
DRR 13(8) TEA PGMEA 41.7 0.20 rectangular (64) DRR 14(8) (0.125)
(480) II-15 Polymer 9 PAG 5(2) DRR 13(8) TEA PGMEA 42.1 0.22
rectangular (64) DRR 15(8) (0.125) (480) II-16 Polymer 9 PAG 5(2)
DRR 13(8) TEA PGMEA 45.1 0.22 rectangular (64) DRR 16(8) (0.125)
(480) II-17 Polymer 9 PAG 5(2) DRR 13(8) TEA PGMEA 42.0 0.22
rectangular (64) DRR 17(8) (0.125) (480) II-18 Polymer 9 PAG 5(2)
DRR 13(8) TEA PGMEA 40.9 0.22 rectangular (64) DRR 18(8) (0.125)
(480) II-19 Polymer 9 PAG 5(2) DRR 13(16) TEA PGMEA 41.5 0.22
rectangular (64) ACC 1(4) (0.125) (480) II-20 Polymer 9 PAG 5(2)
DRR 13(16) TEA PGMEA 40.3 0.20 rectangular (64) ACC 2(4) (0.125)
(480)
Comparative Reference Examples II-1 to II-4
[0086] Resist materials were similarly formulated in accordance
with the formulation shown in Table 5 and examined for performance.
The composition and test results of the resist materials are shown
in Table 5.
5TABLE 5 Comparative Reference Photoacid Dissolution Basic Sensi-
Resolu- Example resin generator regulator compound Solvent tivity
tion shape II-1 Polymer 9 PAG 1(2) DRR 15(16) TEA PG/EL 45.9 0.26
rectangular (64) (0.125) (480) II-2 Polymer 9 PAG 1(2) DRR 16(16)
TEA PG/EL 47.7 0.26 some (64) (0.125) (480) positive taper II-3
Polymer 9 PAG 1(2) DRR 17(16) TEA PG/EL 45.0 0.26 rectangular (64)
(0.125) (480) II-4 Polymer 9 PAG 1(2) DRR 18(16) TEA PG/EL 44.5
0.26 rectangular (64) (0.125) (480)
[0087] It is evident from Tables 1 to 5 that the resist materials
having the ester compounds of the invention blended therein show a
higher sensitivity and resolution than the resist materials having
the prior art dissolution regulators blended therein.
[0088] Japanese Patent Application No. 11-138090 are incorporated
herein by reference.
[0089] Although some preferred embodiments have been described,
many modifications and variations may be made thereto in light of
the above teachings. It is therefore to be understood that the
invention may be practiced otherwise than as specifically described
without departing from the scope of the appended claims.
* * * * *