U.S. patent number RE40,211 [Application Number 09/810,650] was granted by the patent office on 2008-04-01 for diazodisulfones.
This patent grant is currently assigned to Wako Pure Chemical Industries, Ltd.. Invention is credited to Hirotoshi Fujie, Masaaki Nakahata, Keiji Oono, Fumiyoshi Urano.
United States Patent |
RE40,211 |
Urano , et al. |
April 1, 2008 |
Diazodisulfones
Abstract
##STR00001## wherein R.sup.1 is a C.sub.3-8 branched or cyclic
alkyl group, and R.sup.2 is a C.sub.1-8 straight-chain, branched or
cyclic alkyl group, is effective as a photoacid generator when used
in a photoresist material for light of 300 nm or less.
Inventors: |
Urano; Fumiyoshi (Niiza,
JP), Nakahata; Masaaki (Higashimatsuyama,
JP), Fujie; Hirotoshi (Kawagoe, JP), Oono;
Keiji (Sakado, JP) |
Assignee: |
Wako Pure Chemical Industries,
Ltd. (Osaka, JP)
|
Family
ID: |
27282700 |
Appl.
No.: |
09/810,650 |
Filed: |
March 15, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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07646909 |
Jan 28, 1991 |
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Reissue of: |
07962089 |
Oct 16, 1992 |
05216135 |
Jun 1, 1993 |
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Foreign Application Priority Data
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Jan 30, 1990 [JP] |
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02-019614 |
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Current U.S.
Class: |
534/556; 534/558;
534/565 |
Current CPC
Class: |
G03F
7/039 (20130101) |
Current International
Class: |
C07C
245/12 (20060101); C07C 245/16 (20060101) |
Field of
Search: |
;534/558 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1231789 |
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May 1987 |
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GB |
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2-27660 |
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Mar 1984 |
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JP |
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62-115440 |
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May 1987 |
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JP |
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3-223863 |
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Oct 1991 |
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JP |
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Other References
Chem. Abstract, 68 (13): 59304j. cited by other .
Chemical Abstracts, 60, 19928h (1984). cited by other .
Chemische Berichte Jahrg., 97, 735 (1964). cited by other .
Polymer Engineering and Science, Dec. 1983, vol. 23, No. 18, pp.
1012-1018. cited by other .
SPIE; 920, p. 67 (988). cited by other .
Chemische Berichte Jahrg., 99, 1966, vol. 9, No. 5. pp. 1704-1711.
cited by other .
J. Chem. Cos. Perkin Trans. II, No. 10., pp. 1273-1278 (1982).
cited by other .
Chemical Abstracts. 114. 33140w (1991). cited by other.
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Primary Examiner: Stockton; Laura L.
Attorney, Agent or Firm: Angell; Edwards Palmer & Dodge
LLP
Parent Case Text
This application is a continuation of application Ser. No. 646,909
filed Jan. 28, 1991 now abandoned.
.Iadd.This application is a reissue application of U.S. Pat. No.
5,216,135, issued Jun. 1, 1993, and has been merged with
reexamination application 90/004,812 filed Oct. 23, 1997.
Application 11/410,338 filed Apr. 25, 2006, now abandoned, and
Application 11/714,265 filed Mar. 6, 2007 are divisional reissues
of the present reissue application..Iaddend.
Claims
What is claimed is:
.[.1. A diazodisulfone compound of the formula: ##STR00024##
wherein R.sup.1 is a branched or cyclic alkyl group having 3 to 8
carbon atoms; and R.sup.2 is a straight-chain, branched or cyclic
alkyl group having 1 to 8 carbon atoms..].
.[.2. A diazodisulfone compound according to claim 1, wherein
R.sup.1 is a cyclopentyl group, a cyclohexyl group, an isopropyl
group, a sec-butyl group, a tert-butyl group or an isoamyl group;
and R.sup.2 is a methyl group, an ethyl group, a cyclopentyl group,
a cyclohexyl group, an isopropyl group, a sec-butyl group, a
tert-butyl group or an isoamyl group..].
.[.3. A diazodisulfone compound according to claim 1, which is
bis(cyclohexylsulfonyl)diazomethane,
cyclohexylsulfonylethylsulfonyldiazomethane,
bis(isopropylsulfonyl)diazomethane,
bis(tert-butylsulfonyl)diazomethane,
bis(sec-butylsulfonyl)diazomethane,
tert-butylsulfonylmethylsulfonyldiazomethane,
tert-butylsulfonylcyclohexylsulfonyldiazomethane,
bis(cyclopentylsulfonyl)diazomethane,
cyclopentylsulfonyl-tert-butylsulfonyldiazomethane, or
bis(isoamylsulfonyl)diazomethane..].
.[.4. A diazodisulfone compound of the formula: ##STR00025##
wherein R.sup.1 is a branched or cyclic alkyl group having 3 to 8
carbon atoms; and R.sup.2 is a branched or cyclic alkyl group
having 3 to 8 carbon atoms..].
.[.5. A compound according to claim 4, wherein R.sup.1 is a
branched alkyl group having 3 to 8 carbon atoms; and R.sup.2 is a
branched alkyl group having 3 to 8 carbon atoms..].
.[.6. A compound according to claim 4, wherein R.sup.1 is a cyclic
alkyl group having 3 to 8 carbon atoms; and R.sup.2 is a cyclic
alkyl group having 3 to 8 carbon atoms..].
7. A .[.compound according to claim 4,.]. .Iadd.diazodisulfone
compound of the formula: ##STR00026## .Iaddend. wherein R.sup.1 is
a branched alkyl group having 3 to 8 carbon atoms; and R.sup.2 is a
cyclic alkyl group having 3 to 8 carbon atoms.
Description
BACKGROUND OF THE INVENTION
This invention relates to a diazodisulfone compound useful as a
photosensitive material for deep ultraviolet (UV) light, electron
beams, X-rays, etc. More particularly, the present invention
relates to a diazodisulfone compound which generates an acid by
irradiating with KrF excimer laser light (248.4 nm), ArF excimer
laser light (193 nm), electron beams, X-rays, etc.
With recent higher density and larger scale integration of
semiconductor devices, wavelengths used in exposing devices for
minute processing, particularly for lithography become shorter and
shorter. Now, KrF excimer laser light (248.4 nm) is studied. In
order to use the KrF excimer laser as a light source, a resist
material is required to act highly sensitively to light
exposed.
One method for making the resist material highly sensitive is to
contain therein a compound which has a property of generating an
acid when exposed to light, that is, to use a so-called chemical
amplified resist material [e.g. H. Ito et al: Polym. Eng. Sci.,
vol. 23, 1012 (1983)]. As the compound generating an acid by
exposing to light (hereinafter referred to as "photoacid
generator"), there are proposed onium salts such as allyl diazonium
sails, diallyl iodonium salts, triallyl sulfonium salts (e.g. U.S.
Pat. Nos. 4,491,628 and 4,603,101, Japanese Patent Examined
Publication No. 2-27660, Japanese Patent Unexamined Publication No.
62-115440), 2,6-dinitrobenzyl tosylate [e.g. F.M. Houlihan, et al:
SPIE, vol. 920, Advances in Resist Technology and Processing V,
page 67 (1988)]. But, since these compounds used as the photoacid
generator have aromatic rings, there is a problem in that resist
materials containing these compounds lower transmittance for light.
Further, in the case of onium salts, resist materials containing
onium salts have a problem in that the resist materials are poor in
solution stability during storage.
Therefore, a resist material overcoming the problem of poor
solution stability caused by a property of photoacid generator, and
improving transmittance for deep UV light and KrF excimer laser
light is desired.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a
diazodisulfone compound used as an photoacid generator overcoming
the problems mentioned above, having high transmittance for light
of 300 nm or less, e.g. deep UV light, KrF excimer laser light, ArF
excimer laser light, generating easily an acid by exposure to the
light mentioned above or by irradiation with electron beams,
X-rays, etc., being excellent in solution stability in the resist
material, and having a function of improving a dissolution
inhibiting effect of the resist material for an alkali developing
solution.
The present invention provides a diazodisulfone compound of the
formula: ##STR00002## wherein R.sup.1 is a branched or cyclic alkyl
group having 3 to 8 carbon atoms; and R.sup.2 is a straight-chain,
branched or cyclic alkyl group having 1 to 8 carbon atoms.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing a UV spectral curve of an acetonitrile
solution of bis-cyclohexylsulfonyl diazomethane obtained in Example
1.
FIGS. 2(a) to 2(c) are schematic cross-sectional views explaining a
positive tone pattern forming process using a resist material
containing the compound of the present invention as an photoacid
generator.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The diazodisulfone compound of the formula: ##STR00003## wherein
R.sup.1 is a branched or cyclic alkyl group having 3 to 8 carbon
atoms; and R.sup.2 is a straight-chain, branched or cyclic alkyl
group having 1 to 8 carbon atoms, has high transmittance for light
of 300 nm or less, e.g. deep UV light, KrF excimer laser light,
etc., generates an acid easily by exposure to such light or by
irradiation with electron beams, X-rays, etc., the acid generated
functioning effectively on chemical amplification of the resist
material with heating, and is excellent by itself in solution
stability in the resist material.
In the formula (I), the alkyl group in the definition of R.sup.1
includes, for example, an isopropyl group, an isobutyl group, a
sec-butyl group, a tert-butyl group, an isoamyl group, a sec-amyl
group, a 2-methylbutyl group, a 2-methyl-2-butyl group, a
1,1-dimethybutyl group, a 2-hexyl group, a 1,1-dimethylpentyl
group, a 1,1-dimethylhexyl group, a cyclopropyl group, a
cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a
cyclooctyl group, etc. The alkyl group in the definition of R.sup.2
includes, for example, a methyl group, an ethyl group, a n-propyl
group, an isopropyl group, a cyclopropyl group, a n-butyl group, an
isobutyl group, a sec-butyl group, a tert-butyl group, an n-amyl
group, an isoamyl group, a sec-amyl group, a 2-methylbutyl group, a
2-methyl-2-butyl group, a cyclopentyl group, a n-hexyl group, a
cyclohexyl group, a n-heptyl group, a n-octyl group, etc.
Preferable examples of the diazodisulfones of the formula (I) are
as follows. Bis(cyclohexylsulfonyl)diazomethane
Cyclohexylsulfonylethylsulfonyldiazomethane
Bis(isopropylsulfonyl)diazomethane
Bis(tert-butylsulfonyl)diazomethane
Bis(sec-butylsulfonyl)diazomethane
tert-Butylsulfonylmethylsulfonyldiazomethane
tert-Butylsulfonylcyclohexylsulfonyldiazomethane
Bis(cyclopentylsulfonyl)diazomethane
Cyclopentylsulfonyl-tert-butylsulfonyldiazomethane
Bis(isoamylsulfonyl)diazomethane, etc.
The compound of the formula (I) has a bulky group of a branched or
cyclic alkyl group at at least one of R.sup.1 and R.sup.2, so that
it per se has a property of low insolubility in an alkali
developing solution. Therefore, a resist material containing such a
compound is consequently lowered in solubility in an alkali
developing solution, resulting in increasing a dissolution
inhibiting effect on so-called non-exposed portions. Such a resist
material is more preferable as a pattern forming material.
On the other hand, when both R.sup.1 and R.sup.2 in the formula (I)
have no bulky groups in contrast to the definitions in the present
invention, for example, R.sup.1 and R.sup.2 are ethyl groups, such
a compound has a property of generating an acid by exposure to KrF
excimer laser light, and also has a property of being dissolved by
itself in the alkali developing solution used for pattern
formation. Thus, when such a compound is used as an photoacid
generator in a chemical amplified resist material and subjected to
pattern formation, both exposed portions and non-exposed portions
are dissolved in the alkali developing solution, resulting in
failing to conduct good pattern formation.
The compound of the formula (I) can be synthesized easily as
follows.
For example, when R.sup.1=R.sup.2, the compound of the formula (I)
can be synthesized by the following reaction scheme (1):
##STR00004##
This is explained in detail as follows.
The compound of the formula: R.sup.1SH (II) wherein R.sup.1 is as
defined above, is reacted with methylene chloride in an organic
solvent in the presence of a base to yield the compound of the
formula: R.sup.1SCH.sub.2SR.sup.1 (III) wherein R.sup.1 is as
defined above.
As the base, there can be used NaOH, KOH, NaH, sodium methoxide,
sodium ethoxide, pyridine, piperidine, morpholine, triethylamine,
N-methylpyrrolidine,
As the organic solvent, there can be used alcohols such as
methanol, ethanol, propanol, isopropenol, etc.; aromatic
hydrocarbons such as benzene, toluene, etc.; cyclic ethers such as
1,4-dioxane, tetrahydrofuran (THF), etc.
Methylene chloride is used usually in an amount of 1 to 20 moles,
preferably 5 to 15 moles, per mole of the compound of the formula
(I).
The reaction is carried out usually at 20.degree. to 100.degree.
C., preferably at 25.degree. to 65.degree. C. for usually 1 to 20
hours, preferably 2 to 10 hours.
The resulting compound of the formula (III) is purified by a
conventional method.
The compound of the formula (III) is, then, reacted with hydrogen
peroxide in a solvent in the presence of a catalyst to yield the
compound of the formula: R.sup.1SO.sub.2CH.sub.2SO.sub.2R.sup.1
(IV) wherein R.sup.1 is as defined above.
The hydrogen peroxide is used usually in an amount of 1 to 10
moles, preferably 2 to 6 moles, per mole of the compound of the
formula (III).
As the catalyst, there can be used sodium tungstate, ammonium
phosphomolibdate, etc.
As the solvent, there can be used water; alcohols such as methanol,
ethanol, propanol, isopropanol, etc.; a mixed solvent of water and
an alcohol, etc.
The reaction is carried out usually at 0.degree. to 100.degree. C.,
preferably at 20.degree. to 80.degree. C., for usually 1 to 20
hours, preferably 1 to 10 hours.
The resulting compound of the formula (IV) is purified by a
conventional method.
Then, the compound of the formula (IV) is reacted with tosyl azide
in a solvent in the presence of a base to yield the compound of the
formula: ##STR00005## wherein R.sup.1 is as defined above.
The tosyl azide is used usually in an amount of 0.5 to 5 moles,
preferably 0.5 to 2 moles, per mole of the compound of the formula
(IV).
As the base, there can be used NaOH, KOH, NaH, sodium methoxide,
sodium ethoxide, pyridine, piperidine, morpholine, triethylamine,
N-methylpyrrolidine, etc.
As the solvent, there can be used water; water-soluble organic
solvents such as methanol, ethanol, propanol, isopropanol, acetone,
1,4-dioxane, etc.; and a mixed solvent of water and a water-soluble
organic solvent.
The reaction is carried out usually at 0.degree. to 50.degree. C.,
preferably at 5.degree. to 30.degree. C., for usually 1 to 20
hours, preferably 1 to 10 hours.
The resulting compound of the formula (V) is purified by a
conventional method.
When R.sup.1 and R.sup.2 are different, the compound of the formula
(I) can be synthesized easily by the following reaction scheme (2):
##STR00006##
This is explained in detail as follows.
The compound of the formula (II) in an amount of 1 mole is mixed
with usually 0.5 to 10 moles, preferably 0.5 to 2 moles of
paraformaldehyde (e.g. n=3), followed by introduction of HCl gas in
an amount of equimolar or mole of the paraformaldehyde at usually
10.degree. C. or lower, preferably -10.degree. to +5.degree. C.
Then, anhydrous calcium chloride is added to the resulting mixture
to carry out the reaction at usually 10.degree. C. or lower,
preferably -10.degree. to +5.degree. C., for usually 1 to 20 hours,
preferably 1 to 10 hours, followed by purification by a
conventional method to yield the compound of the formula:
R.sup.1SCH.sub.2Cl (VI) wherein R.sup.1 is as defined above.
The compound of the formula (VI) is then reacted with the compound
of the formula: R.sup.2SH (VII) wherein R.sup.2 is as defined above
but different from R.sup.1, in a solvent in the presence of a base
to yield the compound of the formula: R.sup.1SCH.sub.2SR.sup.2
(VIII)
The compound of the formula (VI) is used in an amount of usually
0.5 to 5 moles, preferably 0.5 to 2 moles, per mole of the compound
of the formula
As the base, there can be used NaOH, KOH, NaH, sodium methoxide,
sodium ethoxide, etc.
As the solvent, there can be used alcohols such as methanol,
ethanol, isopropanol, etc.
The reaction is carried out usually at 0.degree. to 50.degree. C.,
preferably at 0.degree. to 20.degree. C., for usually 1 to 20
hours, preferably 1 to 10 hours.
The resulting compound of the formula (VIII) is purified by a
conventional method.
The compound of the formula (VIII) is oxidized with hydrogen
peroxide, followed by diazotization with tosylazide, in the same
manner as described in the reaction scheme (1) to yield the
compound of the formula (I).
The compound of the formula (VIII) can also be synthesized by the
following reaction scheme (3): ##STR00007##
This is explained in detail as follows.
The compound of the formula (II) is reacted with the compound of
the formula (VII) and methylene chloride in a solvent in the
presence of a base to yield the compound of the formula (VIII).
The compound of the formula (VII) is used usually in an amount of
0.5 to 5 moles, preferably 0.5 to 2 moles, per mole of the compound
of the formula (II), and methylene chloride is used usually in an
amount of 1 to 20 moles, preferably 5 to 15 moles, per mole of the
compound of the formula (II).
As the base, there can be used NaOH, KOH, NaH, sodium methxoide,
sodium ethoxide, pyridine, piperidine, morpholine, triethylamine,
N-methylpyrrolidine, etc.
As the solvent, there can be used alcohols such as methanol,
ethanol, propanol, isopropanol, etc.; aromatic hydrocarbons such as
benzene, toluene, etc.; cyclic ethers such as 1,4-dioxane,
tetrahydrofuran, etc.
The reaction is carried out usually at 20.degree. to 100.degree.
C., preferably 25.degree. to 65.degree. C. for usually 1 to 20
hours, preferably 2 to 10 hours.
The resulting product is purified by a conventional method such as
distillation, column chromatography, etc. to yield the compound of
the formula (VIII).
The compound of the formula (VIII) is converted to the compound of
the formula (I) in the same manner as described in the reaction
scheme (2).
When R.sup.1 and R.sup.2 are different, the reaction scheme (2) is
preferable from the viewpoint of practical production.
The compound of the formula (I) is effectively used in a chemical
amplified resist material wherein there is used a polymer having a
property of alkali-soluble by the action of an acid. When the
resist material is exposed to KrF excimer laser light or the like,
the compound of the formula (I) present in the exposed portion
generates an acid by the following reaction scheme (4):
##STR00008##
When heat treatment is applied after the exposure step, functional
groups of the polymer in the resist material is subjected to a
chemical change by the acid to become alkali-soluble by the
following reaction scheme (5): ##STR00009## The resulting
alkali-soluble polymer is released into an alkali developing
solution at the time of development.
On the other hand, since non-exposed portions do not generate an
acid, no chemical change takes place even if heat treated to
produce no alkali-soluble groups. Further, since the compound of
the formula (I) has a dissolution inhibiting effect, the
non-exposed portions become difficultly soluble in the alkali
developing solution.
As mentioned above, when pattern formation is carried out by using
a chemical amplified resist material containing the compound of the
formula (I), a large difference in solubility in the alkali
developing solution takes place between the exposed portions and
the non-exposed portions. As a result, there can be formed a
positive tone pattern having good contrast. Further, as is clear
from the reaction scheme (5), since the acid generated by exposure
to light acts catalytically, not only the necessary amount of acid
can be produced by the exposure to light, but also the light
exposure energy amount can be reduced.
Needless to say, the compound of the formula (I) is useful for
producing semiconductors and can be used as a photosensitive
reagent in the field of applying photo reaction such as
photograving, printing plate materials, etc.
The present invention is illustrated by way of the following
Examples.
REFERENCE EXAMPLE 1
(1) Free radical polymerization of p-tert-butoxystyrene
A solution of p-tert-butoxystyrene (17.6 g) in toluene containing
catalytic amount of 2,2'-azobisisobutyronitrile (AIBN) was heated
at 80.degree. C. for 6 hours under nitrogen. After cooling, the
reaction mixture was poured into methanol and the polymer was
precipitated. The polymer was filtered, washed with methanol and
dried under reduced pressure to afford 15. 5 g of
poly(p-tert-butoxystyrene) as white powders.
(2) Synthesis of poly(p-tert-butoxystyrene-p-hydroxystyrene)
A solution of poly(p-tert-butoxystyrene) (15.0 g) obtained in above
(1) and hydrochloric acid (10 ml) in 1,4-dioxane was refluxed for
1.5 hours with stirring. The mixture was cooled, poured into water
and the white solid was precipitated. The polymer was filtered,
washed and dried under reduced pressure to afford 11.8 g of the
title compound as white powders having Mw10000 (GPC with
polystyrene calibration). The composition of the polymer was found
to be p-tert-butoxystyrene and p-hydroxystyrene in a molar ratio of
ca 1:1 based on .sup.1HNMR analysis
REFERENCE EXAMPLE 2
Synthesis of p-toluenesulfonylazide
After dissolving sodium azide (22.5 g, 0.35 mole) in a small amount
of H.sub.2O, the resulting solution was diluted with a 90% ethanol
aqueous solution (130 ml). To this, an ethanol solution dissolving
p-toluenesulfonyl chloride (60 g, 0.32 mole) was added dropwise at
10-25.degree. C., followed by reaction at room temperature for 2.5
hours. The reaction solution was concentrated at room temperature
under reduced pressure. The resulting oily residue was washed with
H.sub.2O several times and dried over anhydrous MgSO.sub.4. After
removing the drying agent by filtration, there was obtained 50.7 g
of the title compound as a colorless oil.
.sup.1HNMR .delta. ppm (CDCl.sub.3): 2.43 (3H, s, CH.sub.3), 7.24
(2H, d, J=8Hz, Ar 3-H, 5-H), 7.67 (2H, d, J=8Hz, Ar 2-H, 6-H).
IR (Neat) .nu.cm.sup.-1: 2120 (--N.sub.3).
EXAMPLE 1
Synthesis of bis(cyclohexylsulfonyl)diazomethane
(1) Synthesis of bis(cyclohexylsulfonyl)methane
To cyclohexylthiol (20.2 g, 0.17 mole), an ethanol solution
dissolving potassium hydroxide (12.0 g, 0.21 mole) was added
dropwise at room temperature and mixture was stirred at
30.degree..+-.5.degree. C. for 30 minutes. Then methylene chloride
(18.2 g, 2.14 mole) was added to this mixture and reacted with
stirring at 50.degree..+-.5.degree. C. for 6 hours. After standing
at room temperature overnight, the reaction mixture was diluted
with ethanol (55 ml) and added with sodium tungstate (0.4 g). Then,
30% hydrogen peroxide (50 g, 0.44 mole) was added dropwise to this
solution at 45.degree.-50.degree. C., reacted with stirring for 4
hours at the same temperature, then added with H.sub.2O (200 ml)
and standed overnight at room temperature. The precipitate was
filtered, washed with H.sub.2O and dried. The resultant solid was
recrystallized from ethanol to give 15.5 g of
bis(cyclohexylsulfonyl)methane as white needles.
mp. 137.degree.-139.degree. C.
.sup.1HNMR .delta. ppm (CDCl.sub.3) 1.13-2.24 (20H, m, cyclohexylic
CH.sub.2.times.10), 3.52-3.66 (2H, m, cyclohexylic CH.times.2),
4.39 (2H, s, CH.sub.2).
IR (KBr-disk) .nu. cm.sup.-1: 1320, 1305.
(2) Synthesis of bis(cyclohexylsulfonyl)diazomethane
To a solution of sodium hydroxide (1.7 g) in a 60% ethanol aqueous
solution (70 ml), bis(cyclohexylsulfonyl)methane (12.1 g, 0.04
mole) obtained in above (1) was added, then an ethanol solution of
p-toluenesulfonyl azide (8.2 g, 0.04 mole) obtained in Reference
Example 2 was added dropwise at 5.degree.-10.degree. C., followed
by the reaction at room temperature for 7 hours. After standing at
room temperature overnight, the precipitate was filtered, washed
with ethanol and dried. The resultant solid was recrystallized from
acetonitrile to give 8.0 g of bis(cyclohexylsulfonyl)diazomethane
as pale yellow prisms.
mp. 130.degree.-131.degree. C.
.sup.1HNMR .delta. ppm (CDCl.sub.3): 1.13-2.25 (20H, m,
cyclohexylic CH.sub.2.times.10), 3.36-3.52 (2H, m, cyclohexylic
CH.sub.2).
IR (KBr-disk) .nu. cm.sup.-1: 2130 (CH.sub.2), 1340, 1320.
Ultraviolet spectrophotometric characteristics of
bis(cyclohexylsulfonyl)diazomethane in acetonitrile solution was
shown in FIG. 1. It is clear that
bis(cyclohexylsulfonyl)diazomethane of the present invention shows
good transmittance between 240 and 300 nm.
EXAMPLE 2
Synthesis of cyclohexylsulfonylethylsulfonyldiazomethane
(1) Synthesis of chloromethyl cyclohexylsulfide
To a mixture of cyclohexylthiol (20.2 g, 0.17 mole) and 80%
paraformaldehyde (6.5 g, 0.17 mole), dry hydrogen chloride was
introduced at -8.degree.-0.degree. C., then anhydrous calcium
chloride was added and stirring was violently continued at
0.degree. C. for 3 hours. After removing the precipitate by
filtration, the filtrate was distilled under reduced pressure to
afford 16.5 g of chloromethylcyclohexylsuflide as a colorless oil
having a boiling point of 100.degree.-103.degree. C./14 mmHg.
(2) Synthesis of cyclohexylsulfonylethylsulfonylmethane
To ethanethiol (5.7 g, 0.09 mole), an ethanol solution dissolving
potassium hydroxide (6 g, 0.09 mole) was added dropwise at room
temperature and mixture was stirred for 15 minutes. Then
chroromethylcyclohexylsulfide (15 g, 0.09 mole) obtained in above
(1) was added dropwise to this mixture at 10.degree..+-.5.degree.
C. and reacted with stirring at that temperature for 3 hours. After
standing at room temperature overnight, the reaction mixture was
diluted with ethanol (30 ml) and H.sub.2O (30 ml) and added with
sodium tungstate (0.3 g). Then, 30% hydrogen peroxide (53 g, 0.47
mole) was added dropwise to this solution at 45.degree.-50.degree.
C., followed by reaction for 6 hours at the same temperature, then
added with H.sub.2O (300 ml) and standed overnight at room
temperature. The precipitate was filtered, washed with H.sub.2O and
dried. The resultant solid (19 g) was recrystallized from ethanol
to give 15.5 g of cyclohexylsulfonylethylsulfonylmethane as white
needles.
mp: 89.degree.-91.degree. C.
.sup.1HNMR .delta. ppm (CDCl.sub.3): 1.13-2.24 (13H, m,
cyclohexylic CH.sub.2.times.5 and CH.sub.2CH.sub.3), 3.44 (2H, q,
J=7.3Hz, CH.sub.2CH.sub.3), 3.53-3.68 (1H, m, cyclohexylic CH),
4.40 (2H, s, CH.sub.2).
IR (KBr-disk) .nu. cm.sup.-1: 1315.
(3) Synthesis of cyclohexylsulfonyl ethylsulfonyldiazomethane
To a solution of sodium hydroxide (1.7 g) in a 60% ethanol aqueous
solution (70 ml), cyclohexylsulfonylethylsulfonylmethane (10.2 g,
0.04 mole) obtained in above (2) was added. Then an ethanol
solution of p-toluenesulfonyl azide (8.2 g, 0.04 mole) obtained in
Reference Example 2 was added dropwise at 5.degree.-10.degree. C.,
followed by reaction at room temperature for 7 hours. After
standing at room temperature overnight, the reaction mixture was
extracted with ethyl acetate (25 ml.times.3), the organic layer was
separated, washed with H.sub.2O and dried over anhydrous
MgSO.sub.4. After removing the drying agent by filtration, the
solvent was evaporated in vacuo, the resultant residue (12 g) was
subjected to column separation [silica gel, Wakogel C-200, a trade
name, manufactured by wako Pure Chemical Industries, Ltd.; eluent,
n-hexane/ethyl acetate/methylene cloride=8/1/0.fwdarw.7/1/1(v/v)]to
give 4.1 g of cyclohexylsulfonylethylsulfonyldiazomethane as pale
yellow crystals.
m.p.: 85.degree.-86.5.degree. C.
.sup.1HNMR .delta. ppm (CDCl.sub.3): 1.13-2.27 (13H, m,
cyclohexylic CH.sub.2.times.5 and CH.sub.2CH.sub.3), 3.38-3.54 (3H,
m, cyclohexylic CH and CH.sub.2CH.sub.3).
IR (KBr-disk) .nu. cm.sup.-1: 2120 (CH.sub.2), 1325.
EXAMPLES 3-5
Using various thiol compounds of the formula (II) as a starting
material, the syntheses were carried out in the same manner as
described in Example 1 to give the corresponding
bis(alkylsulfonyl)diazomethane. The results are summarized in Table
1.
TABLE-US-00001 TABLE 1 Appearance .sup.1HNMR .delta. ppm Example R1
(purification) m.p. (CDCl.sub.3) IR (KBr) 3 ##STR00010## pale
yellow needles (recrystallization from methanol)
82.about.84.degree. C. 1.46(12H, d, J=7Hz, ##STR00011## 2120
cm.sup.-1 3.74(2H, m, J=7Hz, ##STR00012## 1340 cm.sup.-1 1320
cm.sup.-1 4 ##STR00013## pale yellow needles (recrystallization
from ethanol) 121.about.121.5.degree. C. 1.52(18H, s, CH.sub.3
.times. 6) 2120 cm.sup.-1 1330 cm.sup.-1 1315 cm.sup.-1 5
##STR00014## pale yellow oil (column separation: silica gel, wako
Gel C-200; eluent, n-hexane/ethyl acetate = 20/1) -- 1.14(12H, d,
J=7Hz, ##STR00015## 2120 cm.sup.-1 2.37(2H, m, ##STR00016##
3.38(4H, d, J=7Hz, ##STR00017## 1350 cm.sup.-1 1330 cm.sup.-1
EXAMPLES 6 and 7
Using various thiol compounds of the formula (II) and of the
formula (VII) severally as a straight material, the syntheses were
carried out in the same manner as described in Example 2 to give
the corresponding diazomethane derivatives. The results are
summarized in Table 2.
TABLE-US-00002 TABLE 2 Appearance .sup.1HNMR .delta. ppm Example R1
R2 (purification) m.p. (CDCl.sub.3) IR (KBr) 6 ##STR00018##
CH.sub.3-- pale yellow needles (recrystallization from ethanol)
90.5.about.92.degree. C. 1.51(9H, s, --C(CH.sub.3).sub.3) 3.39(3H,
s, --SO.sub.2CH.sub.3) 2120 cm.sup.-11335 cm.sup.-1 1310 cm.sup.-1
7 ##STR00019## ##STR00020## pale yellow needles (recrystallization
from n-hexane/ ethyl ether) 86.about.88.degree. C. 1.13-2.27(19H,
m, ##STR00021## 2120 cm.sup.-1 3.47-3.63(1H, m, ##STR00022## 1330
cm.sup.-1 1315 cm.sup.-1
COMPARATIVE EXAMPLES 1-3
Using various thiol compounds having a straight-chain alkyl group
as a starting material, the syntheses were carried out in the same
manner as described in Example 1 to afford the corresponding
bis(alkylsulfonyl)diazomethane. The results are summarized in Table
3.
TABLE-US-00003 TABLE 3 ##STR00023## Comparative Appearance
.sup.1HNMR .delta. ppm Example R (purification) m.p. (CDCl.sub.3)
IR 1 C.sub.2H.sub.5-- pale yellow needles 88.7.about.89.7.degree.
C. 1.46(6H, t, J=7.3Hz, 2140 cm.sup.-1 (recrystallization
--CH.sub.2CH.sub.3 .times. 2) from methanol) 3.48(4H, q, J=7.3Hz,
1335 cm.sup.-1 --CH.sub.2CH.sub.3 .times. 2) 2
CH.sub.3(CH.sub.2).sub.3-- pale yellow needles 44.about.47.degree.
C. 0.98(6H, t, J=7Hz, 2145 cm.sup.-1 (column separation: --CH.sub.3
.times. 2) silica gel, 1.42-1.56(4H, m, Wakogel C-200;
--CH.sub.2CH.sub.3 .times. 2) eluent, n-hexane/ 1.79-1.90(4H, 1350
cm.sup.-1 ethyl acetate = --SO.sub.2CH.sub.2CH.sub.2 .times. 2)
20/1) 3.38(4H, d, J=7Hz, 1335 cm.sup.-1
--SO.sub.2CH.sub.2CH.sub.2-- .times. 2) 3
CH.sub.3(CH.sub.2).sub.7-- pale yellow oil -- 0.82-1.94(30H, m 2120
cm.sup.-1 (column separation: CH.sub.3(CH.sub.2).sub.6-- .times. 2)
silica gel, 3.43(4H, t, 1340 cm.sup.-1 Wakogel C-200;
--SO.sub.2CH.sub.2-- .times. 2) eluent, n-hexane/ ethyl acetate =
3/1
COMPARATIVE EXAMPLE 4
Synthesis of bis(methylsulfonyl)diazomethane
(1) Synthesis of bis(methylsulfonyl)methane
To a solution of methyl methylsulfinylmethylsulfide (7.0 g, 0.06
mole) and sodium tungsate (0.14 g) in methanol (40 ml) and H.sub.2O
(4 ml), 30% hydrogen peroxide (21 g, 0.19 mole) was added dropwise
at 45.degree.-50.degree. C., then reacted with stirring under
reflux for 8 hours and standed at room temperature overnight. The
reaction solution was poured into H.sub.2O (400 ml), and the
precipitate was filtered, washed with H.sub.2O and dried. The
resultant solid (9.5 g) was recrystallized from ethanol to effort
7.8 g of bis(methylsulfonyl)methane as white leaflets.
m.p.: 148.degree.-149.5.degree. C.
.sup.1HNMR .delta. ppm (CDCl.sub.3): 3.26 (6H, s,
CH.sub.3.times.2), 4.43 (2H, s, CH.sub.2)
IR (KBr-disk) .nu. cm.sup.-1: 1310.
(2) Synthesis of bis(methylsulfonyl)diazomethane
Using bis(methylsulfonyl)methane (7.5 g, 0.04 mole) obtained in
above (1), the reaction was carried out in the same manner as
described in Example 1, (2), and the crude solid (4.5 g) was
chromatographed on silica gel (Wakogel C-200) with n-hexane/ethyl
acetate (8/1 .fwdarw. 4/1 .fwdarw. 3/1) as eluent to give 2.5 g of
bis(methylsulfonyl)diazomethane as white crystals.
m.p.: 120.degree.-124.degree. C.
.sup.1HNMR .delta. ppm (CDCl.sub.3): 3.37 (6H, s,
CH.sub.3.times.2).
IR (KBr-disk) .nu. cm.sup.-1: 2145 (CN.sub.2), 1335, 1320.
APPLICATION EXAMPLE 1
A resist material having the following composition was
prepared:
TABLE-US-00004 Poly(p-tert-butoxystyrene-p- 6.0 g hydroxystyrene)
[Polymer obtained in Reference Example 1, (2)]
Bis(cyclohexylsulfonyl)diazomethane 0.3 g [Photoacid generator
obtained in Example 1, (2)] Diethylene glycol dimethyl ether 13.7
g
Using the resist material, a pattern was formed as shown in FIG. 2.
That is, the resist material was spin coated on a substrate 1 such
as a 6 inch silicon wafer in diameter and prebaked by a hot plate
at 90.degree. C. for 90 seconds to give a resist material film 2 of
1.0 .mu.m thick [FIG. 2 (a)]. The film 2 was selectively exposed to
KrF excimer laser light 3 of 248.4 nm via a mask 4 at a dose of 25
mJ/cm.sup.2 using a projection aligner (5:1 reduction, NA=0.42)
[FIG. 2 (b)]. The exposed film was heated at 110.degree. C. for 90
seconds, then development was carried out using a conventional
alkali aqueous solution (2.38% tetramethylammonium hydroxide
aqueous solution) for 60 seconds to remove exposed regions of the
film 2 by dissolution to give a positive pattern 2a without loss of
film thickness in the unexposed regions [FIG. 2(c)]. The positive
pattern had an aspect ratio of ca. 87 degree and 0.3 .mu.m lines
and spaces were resolved.
APPLICATION EXAMPLES 2 to 7
Resist materials were prepared in the same manner as described in
Application Example 1 except for using the diazodisulfone compounds
obtained in Examples 2 to 7 as the photoacid generator. Patterns
were formed on semiconductor substrates in the same manner as
described in Application Example 1. The results are shown in Table
4.
TABLE-US-00005 TABLE 4 Exposure energy Application Photoacid amount
Resolution Example No. generator (mJ/cm.sup.2) (.mu.m L/S) 2
Example 3 25 0.3 3 Example 4 25 0.3 4 Example 5 30 0.3 5 Example 2
30 0.3 6 Example 6 30 0.3 7 Example 7 25 0.3
As is clear from Table 4, good positive tone patterns are formed by
using the resist materials containing the compound of the formula
(I) as the photoacid generator.
REFERENCE EXAMPLES 3 to 6
Resist materials were prepared in the same manner as described in
Application Example 1 except for using the bis(straight-chain
alkylsulfonyl)diazomethanes obtained in Comparative Examples 1 to
4. Using the resist materials, patterns were tried to form on
semiconductor substrates in the same manner as described in
Application Example 1, but no positive tone patterns were formed,
since non-exposed portions were dissolved at the time of
development.
These results show that the compounds of the formula (I) of the
present invention obtained by introducing a bulky alkyl group into
at least one of R.sup.1 and R.sup.2 moisties of the formula (I)
play an important role to exhibit dissolution inhibiting effect for
the alkali developing solution.
As mentioned above, when the photosensitive resist materials
containing the diazodisulfone compounds of the formula (I) of the
present invention are used for a light source of 300 nm or less
such as deep UV light, KrF excimer laser light (248.4 nm), etc.,
fine patterns with good shapes of submicron order can easily be
obtained.
The compound of the formula (I) of the present invention exhibits
remarkable effects as the photoacid generator when exposed to not
only deep UV light, KrF excimer laser light, but also ArF excimer
laser light, electron beams, and X-rays.
* * * * *