U.S. patent application number 09/746749 was filed with the patent office on 2002-01-24 for organic anti-reflective coating polymer and preparation thereof.
Invention is credited to Baik, Ki-Ho, Hong, Sung-Eun, Jung, Min-Ho.
Application Number | 20020009595 09/746749 |
Document ID | / |
Family ID | 19628985 |
Filed Date | 2002-01-24 |
United States Patent
Application |
20020009595 |
Kind Code |
A1 |
Hong, Sung-Eun ; et
al. |
January 24, 2002 |
Organic anti-reflective coating polymer and preparation thereof
Abstract
The present invention provides an anti-refective coating
polymer, an anti-reflective coating (ARC) composition comprising
the same, methods for producing the same, and methods for using the
same. The anti-refective coating polymer of the present invention
are particularly useful in a submicrolithographic process, for
example, using ArF (193 nm) laser as a light source. The ARC of the
present invention significantly reduces or prevents back reflection
of light and the problem of the CD alteration caused by the
diffracted and/or reflected light. The ARC of the present invention
also significantly reduces or eliminates the standing wave effect
and reflective notching. Thus, the use of ARC of the present
invention results in formation of a stable ultrafine pattern that
is suitable in manufacturing of 1G, and 4G DRAM semiconductor
devices. Moreover, the ARC of the present invention significantly
improves the production yield of such semiconductor devices.
Inventors: |
Hong, Sung-Eun; (Gyunggi-do,
KR) ; Jung, Min-Ho; (Gyunggi-do, KR) ; Baik,
Ki-Ho; (Gyunggi-do, KR) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Family ID: |
19628985 |
Appl. No.: |
09/746749 |
Filed: |
December 22, 2000 |
Current U.S.
Class: |
428/413 ;
525/107 |
Current CPC
Class: |
C08F 220/303 20200201;
Y10S 430/151 20130101; Y10S 430/111 20130101; Y10T 428/31511
20150401; C08F 220/302 20200201; C08F 220/301 20200201 |
Class at
Publication: |
428/413 ;
525/107 |
International
Class: |
B32B 027/38; C08F
008/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 23, 1999 |
KR |
1999-61342 |
Claims
What is claimed is:
1. A polymer of the formula: 16wherein R.sub.a, R.sub.b, R.sub.c,
R.sub.d, and R.sub.e are independently hydrogen or C.sub.1-C.sub.6
alkyl; R.sub.1 to R.sub.4 are independently hydrogen, optionally
substituted C.sub.1-C.sub.5 alkyl, or optionally substituted
alkoxyalkyl; w, x, y and z are mole fractions each of which is
independently in the range of from 0.1to 0.9; and each of l, m, n
and p is independently an integer of 1 to 3.
2. The polymer of claim 1, wherein R.sub.a, R.sub.b, R.sub.c,
R.sub.d, and R.sub.e are methyl.
3. The polymer of claim 2, l, n, and p are 1 and m is 2; R.sub.1 to
R.sub.4 are hydrogen; w, x, y and z are in the ratio of
0.3:0.25:0.15:0.3.
4. A method for preparing a polymer of the formula: 17said method
comprising the steps of polymerizaing an admixture of monomers in
the presence of a polymer initiator, wherein said admixture of
monomers comprises: a monomer of the formula: 18a
hydroxyalkylacrylate monomer of the formula: 19an alkylacrylate
monomer of the formula: 20and a glycidylacrylate monomer of the
formula: 21wherein R.sub.a, R.sub.b, R.sub.c, R.sub.d, and R.sub.e
are independently hydrogen or C.sub.1-C.sub.6 alkyl; R.sub.1 to
R.sub.4 are independently hydrogen, optionally substituted
C.sub.1-C.sub.5 alkyl, or optionally substituted alkoxyalkyl; and
each of l, m, n and p is independently an integer of 1 to 3.
5. The method of claim 4, wherein said polymerization initiator is
selected from the group consisting of
2,2-azobisisobutyronitrile(AIBN), acetylperoxide, laurylperoxide,
and t-butylperoxide.
6. The method of claim 4, wherein said admixture further comprises
a solvent.
7. The method of claim 6, wherein said solvent is selected from the
group consisting of tetrahydrofuran, toluene, benzene, methylethyl
ketone and dioxane.
8. The method of claim 4 further comprising heating said admixture
to temperature in the range of from about 50.degree. C. to about
80.degree. C.
9. The method of claim 4, wherein the mole fraction of each of said
monomers is independently in the range of from about 0.1 to about
0.9.
10. A polymer of the formula: 22wherein R.sub.a, R.sub.b, R.sub.c,
R.sub.d, and R.sub.e are independently hydrogen or alkyl; R.sub.1
to R.sub.4 are independently hydrogen, optionally substituted
C.sub.1-C.sub.5 alkyl, or optionally substituted alkoxyalkyl; w, x,
y and z are mole fractions each of which is independently in the
range of from 0.1 to 0.9; and each of l, m, n and p is
independently an integer of 1 to 3.
11. The polymer of claim 10, wherein R.sub.a, R.sub.c, R.sub.d, and
R.sub.e are methyl.
12. The polymer of claim 11, R.sub.b is hydrogen; l, n and p are 1;
m is 2; R.sub.1 to R.sub.4 are hydrogen; the ratio of w, x, y and z
is 0.3:0.25:0.15:0.3.
13. A method for preparing a polymer of the formula: 23said method
comprising the steps of polymerizaing an admixture of monomers in
the presence of a polymer initiator, wherein said admixture of
monomers comprises: a monomer of the formula: 24a
hydroxyalkylacrylate monomer of the formula: 25an alkylacrylate
monomer of the formula: 26and a glycidylacrylate monomer of the
formula: 27wherein R.sub.a, R.sub.b, R.sub.c, R.sub.d, and R.sub.e
are independently hydrogen or C.sub.1-C.sub.6 alkyl; R.sub.1 to
R.sub.4 are independently hydrogen, optionally substituted
C.sub.1-C.sub.5 alkyl, or optionally substituted alkoxyalkyl; and
each of l, m, n and p is independently an integer of 1 to 3.
14. The method of claim 13, wherein said polymerization initiator
is selected from the group consisting of
2,2-azobisisobutyronitrile(AIBN), acetylperoxide, laurylperoxide,
and t-butylperoxide.
15. The method of claim 13, wherein said admixture further
comprises a solvent.
16. The method of claim 15, wherein said solvent is selected from
the group consisting of tetrahydrofuran, toluene, benzene,
methylethyl ketone and dioxane.
17. The method of claim 13 further comprising heating said
admixture to temperature in the range of from about 50.degree. C.
to about 80.degree. C.
18. The method of claim 13, wherein the mole fraction of each of
said monomers is independently in the range of from about 0.1 to
about 0.9.
19. A polymer of the formula: 28R.sub.a, R.sub.b, R.sub.c, R.sub.d,
and R.sub.e are independently hydrogen or C.sub.1-C.sub.6 alkyl;
R.sub.1 to R.sub.4 are independently hydrogen, optionally
substituted C.sub.1-C.sub.5 alkyl, or optionally substituted
alkoxyalkyl; R.sub.5 is hydrogen, hydroxide, a moiety of the
formula --COCH.sub.3, optionally substituted C.sub.1-C.sub.4 alkyl,
optionally substituted cycloalky, optionally substituted
alkoxyalky, or optionally substituted cycloalkoxyalkyl; w, x, y and
z are mole fractions each of which is independently in the range of
from 0.1 to 0.9; and each of l, m, and n is independently an
integer of 1 to 3.
20. The polymer of claim 19, wherein R.sub.a, R.sub.c and R.sub.d
are methyl.
21. The polymer of claim 20, R.sub.b is hydrogen; l is 2; m is 3; n
is 1; R.sub.1 to R.sub.4 are hydrogen; R.sub.5 is a moiety of the
formula --COCH.sub.3; and the ratio of w, x, y and z is
0.3:0.25:0.15:0.3.
22. The polymer of claim 19, wherein R.sub.a, R.sub.b, R.sub.c and
R.sub.d are methyl.
23. The polymer of claim 22, l is 1; m is 3; n is 1; R.sub.1 to
R.sub.3 are hydrogen; R.sub.4 is methoxy; R.sub.5 is a moiety of
the formula --COCH.sub.3; and the ratio of w, x, y and z is
0.3:0.23:0.17:0.3.
24. method for preparing a polymer of the formula: 29said method
comprising the steps of polymerizing an admixture of monomers in
the presence of a polymer initiator, wherein said admixture of
monomers comprises: a monomer of the formula: 30a
hydroxyalkylacrylate monomer of the formula: 31an alkylacryl ate
monomer of the formula: 32and a glycidyl acryl ate monomer of the
formula: 33wherein R.sub.a, R.sub.b, R.sub.c, R.sub.d, and R.sub.e
are independently hydrogen or C.sub.1-C.sub.6 alkyl; R.sub.1 to
R.sub.4 are independently hydrogen, optionally substituted
C.sub.1-C.sub.5 alkyl, or optionally substituted alkoxyalkyl;
R.sub.5 is hydrogen, hydroxide, a moiety of the formula
--COCH.sub.3, optionally substituted C.sub.1-C.sub.4 alkyl,
optionally substituted cycloalky, optionally substituted
alkoxyalky, or optionally substituted cycloalkoxyalkyl; and each of
l, m, and n is independently an integer of 1 to 3.
25. The method of claim 24, wherein said polymerization initiator
is selected from the group consisting of
2,2-azobisisobutyronitrile(AIBN), acetylperoxide, laurylperoxide,
and t-butylperoxide.
26. The method of claim 24, wherein said admixture further
comprises a solvent.
27. The method of claim 26, wherein said solvent is selected from
the group consisting of tetrahydrofuran, toluene, benzene,
methylethyl ketone and dioxane.
28. The method of claim 24 further comprising heating said
admixture to temperature in the range of from about 50.degree. C.
to about 80.degree. C.
29. The method of claim 24, wherein the mole fraction of each of
said monomers is independently in the range of from about 0.1 to
about 0.9.
30. A method for forming an anti-reflective coating on a substrate,
said method comprising the steps of: (a) admixing an organic
solvent and an anti-reflective coating polymer selected from the
group consisting of a polymer of the formulas: 34and mixtures
thereof, wherein R.sub.a, R.sub.b, R.sub.c, R.sub.d, and R.sub.e
are independently hydrogen or C.sub.1-C.sub.6 alkyl; R.sub.1 to
R.sub.4 are independently hydrogen, optionally substituted
C.sub.1-C.sub.5 alkyl, or optionally substituted alkoxyalkyl;
R.sub.5 is hydrogen, hydroxide, a moiety of the formula
--COCH.sub.3, optionally substituted C.sub.1-C.sub.4 alkyl,
optionally substituted cycloalky, optionally substituted
alkoxyalky, or optionally substituted cycloalkoxyalkyl, w, x, y and
z are mole fractions each of which is independently in the range of
from 0.1 to 0.9; and each of l, m, n, and p is independently an
integer of 1 to 3, (b) coating said admixture on a substrate; and
(c) heating said coated substrate.
31. The method of claim 30, wherein said organic solvent is
selected from the group consisting of ethyl 3-ethoxypropionate,
methyl 3-methoxypropionate, cyclohexanone, and propylene glycol
methyletheracetate.
32. The method of claim 30, wherein the amount of said organic
solvent is from about 200 to about 5,000% by weight of the total
weight of said anti-reflective coating polymers.
33. The method of claim 30, wherein said heating step comprises
heating said coated substrate at temperature in the range of from
about 100.degree. C. to about 300.degree. C. for a period of from
about 10 sec. to about 1,000 sec.
34. An anti-reflective coating composition, comprising a polymer of
the formula: 35or mixtures thereof, wherein R.sub.a, R.sub.b,
R.sub.c, R.sub.d, and R.sub.e are independently hydrogen or
C.sub.1-C.sub.6 alkyl; R.sub.1 to R.sub.4 are independently
hydrogen, optionally substituted C.sub.1-C.sub.5 alkyl, or
optionally substituted alkoxyalkyl; R.sub.5 is hydrogen, hydroxide,
a moiety of the formula --COCH.sub.3, optionally substituted
C.sub.1-C.sub.4 alkyl, optionally substituted cycloalky, optionally
substituted alkoxyalky, or optionally substituted cycloalkoxyalkyl;
w, x, y and z are mole fractions each of which is independently in
the range of from 0.1 to 0.9; and each of l, m, n, and p is
independently an integer of 1 to 3.
35. A semiconductor device produced by a method of claim 30.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the invention
[0002] The present invention relates to an anti-reflective polymer
that is useful in a submicrolithographic process, a composition
comprising the polymer, and a method for preparing the same. In
particular, the present invention relates to a polymer that can be
used in an anti-reflective coating layer to reduce or prevent back
reflection of light and/or to eliminate the standing waves in the
photoresist layer during a submicrolithographic process. The
present invention also relates to a composition comprising the
polymer, and a method for using the same.
[0003] 2. Description of the Prior Art
[0004] In most submicrolithographic processes standing waves and/or
reflective notching of the waves typically occur due to the optical
properties of the lower layer coated on a substrate and/or due to
changes in the thickness of a photosensitive (i.e., photoresist)
film applied thereon. In addition, typical submicrolithographic
processes suffer from a problem of CD (critical dimension)
alteration caused by diffracted and/or reflected light from the
lower layer.
[0005] One possible solution is to apply an anti-reflective coating
(i.e., ARC) between the substrate and the photosensitive film.
Useful ARCs have a high absorbance of the light wavelengths that
are used in submicrolithographic processes. ARCs can be an
inorganic an organic material, and they are generally classified as
"absorptive" or "interfering" depending on the mechanism. For a
microlithographic process using I-line (365 nm wavelength)
radiation, inorganic anti-reflective films are generally used.
Typically, TiN or amorphous carbon (amorphous-C) materials are used
for an absorptive ARC and SiON materials are typically used for an
interfering ARC.
[0006] SiON-based anti-reflective films have also been adapted for
submicrolithographic processes that use a KrF light source.
Recently, use of an organic compound as ARC has been investigated.
It is generally believed that an organic compound based ARCs are
particularly useful in submicrolithographic processes, in
particular those using an ArF light source.
[0007] In order to be useful as an ARC, an organic compound needs
to have many diverse and desirable physical properties. For
example, a cured ARC should not be soluble in solvents because
dissolution of the organic ARC can cause the photoresist
composition layer to peel-off in a lithographic process. One method
for reducing the solubility of cured ARC is to include
cross-linking moieties such that when cured the ARC becomes
cross-linked and becomes insoluble in most solvents used in
lithographic processes. In addition, there should be minimum amount
of migration (i.e., diffusion), if at all, of materials, such as
acids and/or amines, to and from the ARC. If acids migrate from the
ARC to an unexposed area of the positive photoresist film, the
photosensitive pattern is undercut. If bases, such as amines,
diffuse from the ARC to an unexposed area of the positive
photoresist film a footing phenomenon occurs. Moreover, ARC should
have a faster etching rate than the upper photosensitive (i.e.,
photoresist) film to allow the etching process to be conducted
smoothly with the photosensitive film serving as a mask.
Preferably, an organic ARC should be as thin as possible and have
an excellent light reflection prevention property.
[0008] While a variety of ARC materials are currently available,
none of these materials is useful in ArF laser submicrolithographic
processes. In the absence of an ARC, the irradiated light
penetrates into the photoresist film and is back reflected or
scattered from its lower layers or the surface of the substrate
(e.g., semiconductor chip), which affects the resolution and/or the
formation of a photoresist pattern.
[0009] Therefore, there is a need for an ARC material which have a
high absorbance of the wavelengths used in submicrolithographic
processes.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide an
organic polymer that can be used as an ARC material in ArF laser
(193 nm) or KrF laser (248 nm) submicrolithographic processes.
[0011] It is another object of the present invention to provide a
method for preparing an organic polymer that reduces or prevents
diffusion and/or light reflection in submicrolithographi
processes.
[0012] It is a further object of the present invention to provide
an ARC composition comprising such an organic diffusion/reflection
preventing or reducing polymer and a method for producing the
same.
[0013] It is a still further object of the present invention to
provide a method for producing a photoresist pattern using ArF
laser submicrolithographic processes with reduced standing wave
effect.
[0014] It is yet another object of the present invention to provide
a semiconductor device which is produced using the ARC composition
in a submicrolithographic process.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Alkyl groups according to the present invention are
aliphatic hydrocarbons which can be straight or branched chain
groups. Alkyl groups optionally can be substituted with one or more
substituents, such as a halogen, alkenyl, alkynyl, aryl, hydroxy,
amino, thio, alkoxy, carboxy, oxo or cycloalkyl. There may be
optionally inserted along the alkyl group one or more oxygen,
sulfur or substituted or unsubstituted nitrogen atoms. Exemplary
alkyl groups include methyl, ethyl, i-propyl, n-butyl, t-butyl,
fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl,
trichloromethyl, and pentafluoroethyl.
[0016] In a submicrolithography process, an anti-reflective coating
(i.e., ARC) is used to reduce or prevent the standing wave effect
and/or reflective notching which can occurr upon exposure of a
photosensitive layer to light. In addition, the ARC reduces or
eliminates the influence of a back diffraction and reflection of
light from the lower layer. The ARC can also prevent undercutting
and footing problems which can occur upon forming images on
photosensitive materials. To be useful, the ARC must have a high
absorbance at specific wavelengths.
[0017] The present invention provides polymers that comprise a
chromophore substituent which is highly absorptive of light, in
particular at wavelengths of 193 nm and 248 nm. Polymers of the
present invention can further comprise a crosslinking moiety. It
has been found by the present inventors that the presence of such
cross-linking moiety significantly improves the adhesiveness and
dissolution of the ARC. Useful cross-linking moieties include an
epoxide moiety. Without being bound by any theory, it is believed
that heating (i.e., baking) ARC causes opening of the epoxide ring
and creates crosslinking within the ARC polymer, thereby improving
the physical properties of the ARC. In particular, uncured ARC
resins (i.e., polymers) of the present invention are soluble in
most hydrocarbon solvents, thus allowing ARC resins to be easily
coated onto a substrate. However, a cured (i.e., baked) ARC of the
present invention are relatively insoluble in most solvents, thus
preventing dissolution of the ARC in a developing solution. It is
believed that ARCs of the present invention have higher etching
rate than ArF photosensitive films because the crosslinking
moieties are bonded to each other via C--O linkages. This higher
etching rate significantly improves in the etch selection ratio
between the ARC and the photosensitive film.
[0018] In one aspect of the present invention, an anti-reflective
coating polymer is selected from the group consiting of a polymer
of the formula: 1
[0019] and mixtures thereof, wherein
[0020] R.sub.a, R.sub.b, R.sub.c, R.sub.d, and R.sub.e are
independently hydrogen or C.sub.1-C.sub.6 alkyl (preferably
methyl);
[0021] R.sub.1 to R.sub.4 are independently hydrogen, optionally
substituted C.sub.1-C.sub.5 alkyl, or optionally substituted
alkoxyalkyl;
[0022] R.sub.5 is hydrogen, hydroxide, a moiety of the formula
--COCH.sub.3, optionally substituted C.sub.1-C.sub.4 alkyl,
optionally substituted cycloalky, optionally substituted
alkoxyalky, or optionally substituted cycloalkoxyalkyl;
[0023] w, x, y and z are mole fractions each of which is
independently in the range of from 0.1 to 0.9; and
[0024] each of l, m, n, and p is independently an integer of 1 to
3.
[0025] The terminal groups of a polymer depicted in the present
disclosure depend on the particular polymerization initiator used.
In addition, as used throughout this disclosure, it should be
appreciated that the order of monomeric units represented in a
polymer formula does not necessarily indicate the actual order of
such monomeric units in the polymer. Monomeric units represented in
a polymer formula are intended to simply indicate the presence of
such monomeric units in the polymer. Moreover, the variables
represent the total relative ratio of each unit. For example, the
total amount "w" in Formula 1 above can be inter dispersed
throughout the polymer (not necessarily in same concentrations) or
all or majority of such polymeric unit can be concentrated in one
particular location of the polymer.
[0026] Another aspect of the present invention provides a method
for producing an anti-reflective coating polymer, such as those
described above.
[0027] In one particular embodiment of the present invention, the
polymer of Formula 1 is produced by polymerizing a mixture of
monomers comprising:
[0028] a 4-(4-hydroxyphenoxy)acetoxyalcoholacrylate monomer of the
formula: 2
[0029] a hydroxyalkylacrylate monomer of the formula: 3
[0030] an alkylacrylate monomer of the formula: 4
[0031] and a glycidylacrylate monomer of the formula: 5
[0032] in the presence of a polymerization initiator, where
R.sub.a, R.sub.b, R.sub.c, R.sub.d, R.sub.e, R.sub.1 to R.sub.4, l,
m, n and p are those defined above. Each of the monomers is present
in a mole fraction ranging from about 0.1 to about 0.9.
[0033] Another embodiment of the present invention provides a
method for producing the polymer of Formula 2 from a mixture of
monomers comprising:
[0034] 4-(4-hydroxyphenyl)pyruvicalcoholacrylate monomer of the
formula: 6
[0035] the hydroxy alkylacrylate monomer of Formula 15, the
alkylacrylate monomer of Formula 16, and the glycidyl acrylate
monomer of Formula 17 described above in the presence of a
polymerization initiator, where R.sub.a, R.sub.1 to R.sub.4, l, and
p are those defined above. Each of the monomers is present in a
mole fraction ranging from about 0.1 to about 0.9.
[0036] Yet another embodiment of the present invention provides a
method for producing the polymer of Formula 3 from a mixture of
monomers comprising: a vinyl 4-benzoateketone monomer of the
formula: 7
[0037] the hydroxy alkylacrylate monomer of Formula 15, the
alkylacrylate monomer of Formula 16, and the glycidyl acrylate
monomer of Formula 17 described above in the presence of a
polymerization initiator, where R.sub.a, R.sub.1 to R.sub.5, and l
are those defined above. Each of the monomers is present in a mole
fraction ranging from about 0.1 to about 0.9.
[0038] Preferably, mixtures of monomers described above further
comprise an organic solvent. Useful organic solvents in
polymerization are well known to one of ordinary skill in the art.
In particular, a polymerization solvent is selected from the group
consisting of tetrahydrofuran, toluene, benzene, methylethyl
ketone, dioxane, and mixtures thereof.
[0039] Useful polymerization initiators include those well known to
one of ordinary skill in the art, such as
2,2-azobisisobutyronitrile (AIBN), acetylperoxide, laurylperoxide
and t-butylperoxide.
[0040] Preferably, the polymerization reaction is conducted at
temperature in the range of from about 50.degree. C. to about
80.degree. C.
[0041] Another aspect of the present invention provides an ARC
composition comprising a polymer the Formula 1, 2, 3, or mixtures
thereof. It has been found by the present inventors that such an
ARC composition is particularly useful in a submicrolithography
process. The ARC composition can further include an organic
solvent.
[0042] Still another aspect of the present invention provides a
method for producing the ARC composition described above compring
the steps of admixing the ARC polymer described above with an
organic solvent. Useful organic solvents for ARC composition
include conventional organic solvent. Preferred organic solvents
for ARC composition include ethyl 3-ethoxypropionate, methyl
3-methoxypropionate, cyclohexanone, propylene glycol
methyletheracetate, and mixtures thereof. The amount of organic
solvents for ARC composition is preferably in the amount of from
about 200 to about 5,000% by weight relative to the total weight of
the ARC polymers used.
[0043] Further aspect of the present invention provides a method
for forming an ARC on a substrate. In one embodiment, the ARC
compositing described above is coated on a substrate, such as a
wafer, and the coated substrate is heated (e.g., baked). The ARC
composition can be filtered prior to being coated onto the
substrate. Heating of the coated substrate is preferably conducted
at temperature in the range of from about 100.degree. C. to about
300.degree. C. for a period of from about 10 sec. to about 1,000
sec. Heating the coated substrate produces a film of crosslinked
ARC polymer.
[0044] It has been found by the present inventors that the ARCs of
the present invention exhibit high performance in
submicrolithographic processes, in particular using KrF (248 nm),
ArF (193 nm) and F.sub.2 (157 nm) lasers as a light source.
[0045] In accordance with yet another aspect, the present invention
provides a semiconductor device produced using the ARC composition
described above.
[0046] Additional objects, advantages, and novel features of this
invention will become apparent to those skilled in the art upon
examination of the following examples thereof, which are not
intended to be limiting.
EXAMPLE 1
Synthesis of 4-(4-Hydroxyphenoxy)Acetoxy Isopropanol Methacrylate
Monomer
[0047] To 100 g of tetrahydrofuran (THF) was added 0.35 moles of
4-hydroxyphenylacetic acid, a solution of 0.35 moles of p-toluene
sulfonic acid in 100 g of THF, and 0.3 moles of
glycidylmethacrylate (containing 0.03 moles of 4-methoxyphenyl as a
polymerization inhibitor). The resulting solution was stirred for
24 hours under nitrogen atmosphere. During reaction progress was
monitored using a thin layer chromatography (TLC). The reaction
mixture was washed with deionized water. The organic phase was
extracted, dried over MgSO.sub.4, and distilled under vacuum to
afford the title compound of Formula 4. Yield: 85-90 %. 8
EXAMPLE 2
Synthesis of 4-(4-Hydroxyphenyl) Pyruvicisopropanol Methacrylate
Monomer
[0048] To 100 g of tetrahydrofuran (THF) was added 0.35 moles of
4-hydroxyphenylpyruvic acid, a solution of 0.35 moles of p-toluene
sulfonic acid in 100 g of THF, and 0.3 moles of
glycidylmethacrylate (containing 0.03 moles of 4-methoxyphenyl as a
polymerization inhibitor). The resulting solution was stirred for
10 hours or longer under nitrogen atmosphere. The reaction mixture
was washed with deionized water, and the organic phase was
extracted, dried over MgSO.sub.4, and distilled under vacuum to
afford the title compound of Formula 5. Yield: 80-85 %. 9
EXAMPLE 3
Synthesis of Vinyl 4-(2-Butanone)Benzoate Monomer
[0049] To 0.35 moles of triethylamine was added 0.35 moles of
4-(4-hydroxyphenyl)-2-butanone and 0.33 moles of acryloylchloride.
The resulting mixture was stirred for 24 hours or longer under
nitrogen atmosphere while being cooled to maintain a constant
temperature during the exothermic reaction. The reaction solution
was neutralized with 1N sulfuric acid solution and washed with
deionized water, and the organic phase was extracted, dried over
MgSO.sub.4 to afford the title compound of Formula 6. Yield:
90-95%. 10
EXAMPLE 4
Synthesis of Vinyl 4-(3-Methoxy)Benzoate Acetone Monomer
[0050] To 0.35 moles of triethylamine was added 0.35 moles of
4-hydroxy-3-methoxyphenylacetone and 0.33 moles of
acryloylchloride. The resulting solution was stirred for 24 hours
or longer under nitrogen atmosphere while being cooled to maintain
a constant temperature during the exothermic reaction. The reaction
mixture was neutralized with 1N sulfuric acid solution and washed
with deionized water, after which the organic phase was extracted,
dried over MgSO.sub.4 to afford the title compound of Formula 7.
Yield: 90-95 %. 11
EXAMPLE 5
Synthesis of Poly
[4-(4-Hydroxyphenoxy)Acetoxyisopropanolmethacrylate-Hydr-
oxyethylmethacrylate-Methylmethacrylate-Glycidylmethaerylate]Quaternary
Copolymer
[0051] To a 500 ml round-bottom flask was added 0.3 moles of
4-(4-hydroxyphenoxy)acetoxyisopropanolmethacrylate, 0.25 moles of
hydroxyethylmethacrylate, 0.1 mole of methylmethacrylate, 0.3 moles
of glycidylmethacrylate, 300 g of THF, and 0.1-3 g of
2,2'-azobisisobutyronitrile (AIBN). The resulting mixture was
stirred at 60-75.degree. C. for 5-20 hours under nitrogen
atmosphere. The resulting solution was precipitated in ethyl ether
or n-hexane and the precipitate was filtered and dried to afford
poly[4-(4-hydroxyphenoxy)acetoxyiso-prop-
anolmethacrylate-hydroxyethylmethacrylate-methylmethacrylate-glycidylmetha-
crylate] resin of Formula 8. Yield: 65-70%. 12
EXAMPLE 6
Synthesis of -Poly
[4-(4-Hydroxyphenyl)Pyruvicisopropanolmethacrylate-Hydr-
oxyethylacrylate-Methylmethacrylate-Glycidylmethacrylate]Quaternary
Copolymer
[0052] To a 500 ml round-bottom flask was added 0.3 moles of
4-(4-hydroxyphenyl)pyruvicisopropanolmethacrylate, 0.2 moles of
hydroxyethylacrylate, 0.15 moles of methylmethacrylate, 0.3 moles
of glycidylmethacrylate, 300 g of THF, and 0.1-3 g of AIBN. The
resulting mixture was stirred at 60-75.degree. C. for 5-20 hours
under nitrogen atmosphere. The resulting solution was precipitated
in ethyl ether or n-hexane. The precipitate was filtered and dried
to afford poly[4-(4-glycidylmethacrylate] resin of Formula 9.
Yield: 65 -70%. 13
EXAMPLE 7
Synthesis of Poly[Vinyl
4-(2-Butanone)Benzoate-Hydroxypropylacrylate-Methy-
lmethacrylate-Glycidylmethaerylate]Quaternary Copolymer
[0053] To a 500 ml round-bottom flask was added 0.3 moles of vinyl
4-(2-butanone)benzoate, 0.25 moles of hydroxypropylacrylate, 0.1
mole of methylmethacrylate, 0.3 moles of glycidylmethacrylate, 300
g of THF, and 0.1-3 g of AIBN. The reaction mixture was stirred at
60-75.degree. C. for 5-20 hours under nitrogen atmosphere. The
solution was precipitated in ethyl ether or n-hexane. The
precipitate was filtered and dried to afford poly[viny
4-(2-butanone)benzoate-hydroxypropylacrylate-methylmethacrylate-
-glycidylmethacrylate] resin of Formula 10. Yield: 65-70%. 14
EXAMPLE 8
Synthesis of Poly[Vinyl
4-(3-Methoxy)Benzoateacetone-Hydroxypropylmethacry-
late-Methylmethyacrylate-Glycidylmethacrylate]Quaternary
Copolymer
[0054] To a 500 ml round-bottom flask was added 0.3 moles of vinyl
4-(3-methoxy)benzoateacetone, 0.23 moles of hydroxypropylacrylate,
0.1 mole of methylmethacrylate, 0.3 moles of glycidylmethacrylate,
300 g of THF, and 0.1-3 g of AIBN. The resulting mixture was
stirred at 60-75.degree. C. for 5-20 hours under nitrogen
atmosphere. The resulting solution was precipitated in ethyl ether
or n-hexane and the precipitate was filtered and dried to afford
poly[vinyl 4-(3-methoxy)benzoateacetone--
hydroxypropylmethacrylate-methylmethacrylate-glycidylmethacrylate]
resin of Formula 11. Yield: 65-70%. 15
EXAMPLE 9
Formation of ARC
[0055] Polymers of Examples 5 to 8 were independently dissolved in
propyleneglycol methylether acetate (PGMEA). These solutions, alone
or in combination with 0.1-30 % by weight of at least one additive
selected from conventional anthracene additives. The resulting
solutions were filtered, coated on a wafer, and hard-baked at
100-300.degree. C. for 10-1,000 sec to form an ARC. A
photosensitive material (i.e., photoresist composition) is coated
on top of the ARC layer and subjected to a submicrolithographic
process to produce an ultrafine photoresist pattern.
[0056] Polymers of the present invention comprise a phenyl group
which is capable of absorbing light that is used in
submicrolithography processes. Additionally, uncured polymer of the
present invention is soluble in most hydrocarbon solvents while the
cured (i.e., hard baked) polymer is insoluble in most solvents.
Thus, polymers of the present invention can be easily coated onto a
substrate and are capable of preventing undercutting and footing
problems that can occur during a photoresist pattern formation on
photosensitive materials (i.e., photoresist compositions).
[0057] Moreover, polymers of the present invention comprise
crosslinking moieties that form C--O bonds, thus providing ARCs
that have a higher etching rate than ArF photosensitive films
resulting in a significantly improved etch selection ratio between
the ARCs and the photosensitive films.
[0058] ARCs of the present invention reduce or eliminate the back
reflection of light from lower layers of the photosensitive film or
the surface of the substrate (e.g., semiconductor element). In
addition, ARCs of the present invention reduce or eliminate the
standing waves effect due to the thickness changes in the
photoresist layer during a submicrolithographic process. Thus, ARCs
of the present invention are useful in forming an ultrafine
photoresist pattern. In particular, use of ARCs of the present
invention in submicrolithographic processes result in formation of
a stable ultrafine pattern that are suitable for 1G, 4G and 16G
DRAM semiconductor devices. And since a stable pattern is formed,
use of ARCs of the present invention greatly improves the
production yield.
[0059] While the present invention has been described herein with
reference to particular embodiments thereof, a latitude of
modification, various changes and substitutions are intended in the
foregoing disclosure. It will be appreciated that in some instances
some features of the invention will be employed without a
corresponding use of other features without departing from the
scope of the invention as set forth herein. Therefore, many
modifications may be made to adapt a particular situation or
material to the teachings of the invention without departing from
the essential scope and spirit of the present invention. It is
intended that the invention not be limited to the particular
embodiment disclosed as the best mode contemplated for carrying out
this invention, but that the invention shall include all
embodiments and equivalents falling within the scope of the
appended claims.
* * * * *