U.S. patent application number 11/680332 was filed with the patent office on 2007-07-05 for stopper for chemical mechanical planarization, method for manufacturing same, and chemical mechanical planarization method.
This patent application is currently assigned to JSR Corporation. Invention is credited to Eiji Hayashi, Norihiko Ikeda, Mutsuhiko Yoshioka.
Application Number | 20070151951 11/680332 |
Document ID | / |
Family ID | 32310752 |
Filed Date | 2007-07-05 |
United States Patent
Application |
20070151951 |
Kind Code |
A1 |
Yoshioka; Mutsuhiko ; et
al. |
July 5, 2007 |
STOPPER FOR CHEMICAL MECHANICAL PLANARIZATION, METHOD FOR
MANUFACTURING SAME, AND CHEMICAL MECHANICAL PLANARIZATION
METHOD
Abstract
A stopper for chemical mechanical planarization comprising an
organosilicon polymer, in particular a polycarbosilane, is
provided. The stopper used for polishing wafers with a wiring
pattern in the manufacture of semiconductor devices to protect
interlayer dielectric films made of a material such as SiO.sub.2,
fluorine dope SiO.sub.2, or organic or inorganic SOG (Spin-on
glass) from damages during the chemical mechanical planarization
process.
Inventors: |
Yoshioka; Mutsuhiko; (Tokyo,
JP) ; Hayashi; Eiji; (Tokyo, JP) ; Ikeda;
Norihiko; (Tokyo, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
JSR Corporation
5-6-10, Tsukiji, Chuo-ku
Tokyo
JP
|
Family ID: |
32310752 |
Appl. No.: |
11/680332 |
Filed: |
February 28, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10726592 |
Dec 4, 2003 |
7189651 |
|
|
11680332 |
Feb 28, 2007 |
|
|
|
Current U.S.
Class: |
216/88 ;
257/E21.26; 257/E21.304; 257/E21.576; 257/E21.583; 427/515;
438/692 |
Current CPC
Class: |
B24B 37/042 20130101;
H01L 21/3212 20130101; H01L 21/02126 20130101; H01L 21/3121
20130101; H01L 21/7684 20130101; C09D 183/16 20130101; H01L
21/76829 20130101; H01L 21/02282 20130101 |
Class at
Publication: |
216/088 ;
427/515; 438/692 |
International
Class: |
C03C 15/00 20060101
C03C015/00; H01L 21/461 20060101 H01L021/461; C08J 7/04 20060101
C08J007/04; B44C 1/22 20060101 B44C001/22 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 6, 2002 |
JP |
2002-354528 |
Claims
1-4. (canceled)
5. A method for producing a stopper for chemical mechanical
planarization comprising applying a coating solution comprising (A)
a polycarbosilane and (B) an organic solvent to a substrate and
heating the coating.
6. A chemical mechanical planarization method for removing a
metallic film formed on an insulating film using a polishing
solution characterized by providing a stopper for chemical
mechanical planarization comprising polycarbosilane between the
insulating film and metal film.
7. The chemical mechanical planarization method according to claim
6, wherein the metallic film comprises a first metal film of a
barrier metal and a second metal film of copper, an alloy
containing copper as a main component, or a copper compound.
8. A chemical mechanical planarization method comprising forming a
layer having an opening on a semiconductor region, the layer
comprising an insulating film formed on the semiconductor region
and a stopper for chemical mechanical planarization formed on
insulating film, depositing a first metallic film of a barrier
metal and a second metallic film of copper, an alloy containing
copper as a main component, or a copper compound in the stopper for
chemical mechanical planarization and the opening to fill the
opening with the deposited metal films, and removing the second
metallic film on the stopper for chemical mechanical planarization
using a chemical mechanical planarization solution.
9. The method of claim 5, wherein the polycarbosilane (A) of the
coating solution consists of structural units of the following
formula (1), ##STR3## wherein R.sup.1 and R.sup.2 independently
represent a hydrogen atom, an alkyl group having 1-30 carbon atoms
that may have a substituent, an alkenyl group having 1-30 carbon
atoms that may have a substituent, an alkynyl group having 1-30
carbon atoms that may have a substituent, or an aromatic group that
may have a substituent and R.sup.3 represents --C.ident.C--,
--CH.sub.2--that may have a substituent linked with at least one
--C.ident.C-- group, an alkylene group having 2-30 carbon atoms
that may have a substituent linked with at least one --C.ident.C--
group, an alkenylene group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-- group, an
alkynylene group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-- group, or a
divalent aromatic group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-- group.
10. The method of claim 5, which is carried out to form a chemical
mechanical planarization stopper film consisting of the
polycarbosilane polymer, wherein the film is present on the surface
of the substrate.
11. The method of claim 6, wherein the stopper for chemical
mechanical planarization consists of a polycarbosilane polymer
consisting of structural units of the following formula (1),
##STR4## wherein R.sup.1 and R.sup.2 independently represent a
hydrogen atom, an alkyl group having 1-30 carbon atoms that may
have a substituent, an alkenyl group having 1-30 carbon atoms that
may have a substituent, an alkynyl group having 1-30 carbon atoms
that may have a substituent, or an aromatic group that may have a
substituent and R.sup.3 represents --C.ident.C--, --CH.sub.2-- that
may have a substituent linked with at least one --C.ident.C--
group, an alkylene group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-- group, an
alkenylene group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-- group, an
alkynylene group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-group, or a
divalent aromatic group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-- group.
12. The method of claim 8, wherein the stopper consists of a
polycarbosilane polymer that consists of structural units of the
following formula (1), ##STR5## wherein R.sup.1 and R.sup.2
independently represent a hydrogen atom, an alkyl group having 1-30
carbon atoms that may have a substituent, an alkenyl group having
1-30 carbon atoms that may have a substituent, an alkynyl group
having 1-30 carbon atoms that may have a substituent, or an
aromatic group that may have a substituent and R.sup.3 represents
--C.ident.C--, --CH.sub.2-- that may have a substituent linked with
at least one --C.ident.C-- group, an alkylene group having 2-30
carbon atoms that may have a substituent linked with at least one
--C.ident.C-- group, an alkenylene group having 2-30 carbon atoms
that may have a substituent linked with at least one --C.ident.C--
group, an alkynylene group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-- group, or a
divalent aromatic group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-- group.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a stopper for chemical
mechanical planarization. More particularly, the present invention
relates to a stopper film used for polishing wafers with a wiring
pattern in the manufacture of semiconductor devices (this polishing
operation is herein referred to as "chemical mechanical
planarization" which may be abbreviated from time to time as "CMP")
to protect interlayer dielectric films made of a material such as
SiO.sub.2, fluorine dope SiO.sub.2, or organic or inorganic SOG
(Spin-on glass) from damages during the CMP process and to a method
for chemical mechanical planarization using the stopper film.
[0003] 2. Description of Background Art
[0004] Conventionally, aqueous type dispersion media containing
inorganic particles of colloidal silica and colloidal alumina have
been widely used as a polishing agent in CMP for polishing metal
wiring, barrier membranes, and the like in semiconductor devices.
Problems with the use of such aqueous type dispersion media in the
CMP process are production of scratches in interlayer dielectric
films and peeling of the films.
[0005] An object of the present invention is to solve these
problems and to reduce damages to the interlayer dielectric films
during the CMP process by laminating a specific film on the
interlayer dielectric films.
SUMMARY OF THE INVENTION
[0006] The above object can be achieved in the present invention by
a stopper for chemical mechanical planarization comprising an
organosilicon polymer.
[0007] In a preferred embodiment of the present invention, the
organosilicon polymer is a polycarbosilane.
[0008] In a further preferred embodiment of the present invention,
the organosilicon polymer is at least one polymer selected from the
group consisting of polymers having the structural unit of the
following formula (1), ##STR1## wherein R.sup.1 and R.sup.2
independently represent a hydrogen atom, an alkyl group having 1-30
carbon atoms that may have a substituent, an alkenyl group having
1-30 carbon atoms that may have a substituent, an alkynyl group
having 1-30 carbon atoms that may have a substituent, or an
aromatic group that may have a substituent and R.sup.3 represents
--C.ident.C--, --CH.sub.2-- that may have a substituent linked with
at least one --C.ident.C-- group, an alkylene group having 2-30
carbon atoms that may have a substituent linked with at least one
--C.ident.C-- group, an alkenylene group having 2-30 carbon atoms
that may have a substituent linked with at least one --C.ident.C--
group, an alkynylene group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-- group, or a
divalent aromatic group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-- group.
[0009] The above-described object can also be achieved in the
present invention by a coating solution for forming a stopper for
chemical mechanical planarization comprising a polycarbosilane and
an organic solvent.
[0010] The above-described object can be further achieved in the
present invention by a method for producing a stopper for chemical
mechanical planarization comprising applying a coating solution
comprising (A) a polycarbosilane and (B) an organic solvent to a
substrate and heating the coating.
[0011] The above-described object can be further achieved in the
present invention by a chemical mechanical planarization method for
removing a metallic film formed on an insulating film using a
polishing solution characterized by providing a stopper for
chemical mechanical planarization comprising polycarbosilane
between the insulating film and metal film.
[0012] In the above chemical mechanical planarization method, the
metallic film preferably comprises a first metal film of a barrier
metal and a second metal film of copper, an alloy containing copper
as a main component, or a copper compound.
[0013] The above-described object can be further achieved in the
present invention by a chemical mechanical planarization method
comprising forming a layer having an opening on a semiconductor
region, the layer comprising an insulating film formed on the
semiconductor region and a stopper for chemical mechanical
planarization formed on insulating film, depositing a first
metallic film of a barrier metal and a second metallic film of
copper, an alloy containing copper as a main component, or a copper
compound in the stopper for chemical mechanical planarization and
the opening to fill the opening with the deposited metal films, and
removing the second metallic film on the stopper for chemical
mechanical planarization using a chemical mechanical planarization
solution.
[0014] Other objects, features and advantages of the invention will
hereinafter become more readily apparent from the following
description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows a structure obtained by forming openings
through a two-layer film consisting of an insulating film and a
stopper for chemical mechanical planarization. A metal is then
filled in the openings and layered over the chemical mechanical
planarization stopper.
[0016] FIG. 2 shows the structure obtained by removing unnecessary
metal by chemical mechanical planarization.
DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS
(A) Organosilicon Polymer
[0017] The stopper for CMP of the present invention comprises an
organosilicon polymer having a relative dielectric constant of 4 or
less.
[0018] Polycarbosilane having a relative dielectric constant of 4
or less, preferably 3.5 or less, can be given as such an
organosilicon polymer.
[0019] A particularly preferable organosilicon polymer is a polymer
(hereinafter referred to as "Polymer (1)") having a recurring unit
of the following formula (1): ##STR2## wherein R.sup.1 and R.sup.2
independently represent a hydrogen atom, an alkyl group having 1-30
carbon atoms that may have a substituent, an alkenyl group having
1-30 carbon atoms that may have a substituent, an alkynyl group
having 1-30 carbon atoms that may have a substituent, or an
aromatic group that may have a substituent and R.sup.3 represents
--C.ident.C--, --CH.sub.2-- that may have a substituent linked with
at least one --C.ident.C-- group, an alkylene group having 2-30
carbon atoms that may have a substituent linked with at least one
--C.ident.C-- group, an alkenylene group having 2-30 carbon atoms
that may have a substituent linked with at least one --C.ident.C--
group, an alkynylene group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-- group, a
divalent aromatic group having 2-30 carbon atoms that may have a
substituent linked with at least one --C.ident.C-- group.
[0020] As examples of the alkyl group having 1-30 carbon atoms that
may have a substituent represented by R.sup.1 or R.sup.2, a methyl
group, ethyl group, propyl group, hexyl group, cyclohexyl group,
octyl group, dodecanyl group, trifluoromethyl group,
3,3,3-trifluoropropyl group, chloromethyl group, aminomethyl group,
hydroxymethyl group, silylmethyl group, and 2-methoxyethyl group
can be given; as examples of the alkenyl group having 1-30 carbon
atoms that may have a substituent, a vinyl group, 2-propenyl group,
isopropenyl group, 3-butenyl group, 5-hexenyl group,
1,3-buthadienyl group, and 3,3,3-trifluoro-1-propenyl group can be
given; as examples of the alkynyl group having 1-30 carbon atoms
that may have a substituent, an ethynyl group, 1-propynyl group,
2-propynyl group, butynyl group, trimethylsilylethynyl group, and
phenylethynyl group can be given; and as examples of the aromatic
group that may have a substituent, a phenyl group, naphthyl group,
pyrazinyl group, 4-methylphenyl group, 4-vinylphenyl group,
4-ethynylphenyl group, 4-aminophenyl group, 4-chlorophenyl group,
4-hydroxyphenyl group, 4-carboxyphenyl group, 4-methoxyphenyl
group, and 4-silylphenyl group can be given.
[0021] As examples of the --CH.sub.2-- group that may have a
substituent linked with at least one --C.ident.C-- group
represented by R.sup.3, a methylene group and fluoromethylene group
linked with one or two --C.ident.C-- groups can be given; as
examples of the alkylene group having 2-30 carbon atoms that may
have a substituent linked with at least one --C.ident.C-- group, an
ethylene group, propylene group, tetramethylene group, and
tetrafluoroethylene group linked with one or two --C.ident.C--
groups can be given; as examples of the alkenylene group that
having 2-30 carbon atoms may have a substituent linked with at
least one --C.ident.C-- group, a vinylene group, propenylene group,
and butadienylene group linked with one or two --C.ident.C-- groups
can be given; as examples of the alkynylene group having 2-30
carbon atoms that may have a substituent linked with at least one
--C.ident.C-- group, an ethynylene group, propynylene group, and
butynylene group linked with one or two --C.ident.C-- groups can be
given; and as examples of the aromatic group that may have a
substituent linked with at least one --C.ident.C-- group, a
phenylene group, naphthylene group, biphenylene group,
anthracenylene group, pyridilene group, thiophenylene group,
fluorophenylene group, chlorophenylene group, methylphenylene
group, silylphenylene group, hydroxyphenylene group, aminophenylene
group, Phenylene methylene phenylene group, phenylene oxy phenylene
group, phenylene propylidene phenylene group, and
phenylene(hexafluoropropylidene)phenylene group linked with one or
two --C.ident.C-- groups can be given.
[0022] The organosilicon polymer represented by the formula (1)
used in the present invention is specifically a compound having the
following recurring units: [0023] silylene-ethynylene, [0024]
methylsilylene-ethynylene, [0025] phenylsilylene-ethynylene, [0026]
silylene-ethynylene-1,3-phenylene-ethynylene, [0027]
silylene-ethynylene-1,4-phenylene-ethynylene, [0028]
silylene-ethynylene-1,2-phenylene-ethynylene, [0029]
methylsilylene-ethynylene-1,3-phenylene-ethynylene, [0030]
methylsilylene-ethynylene-1,4-phenylene-ethynylene, [0031]
methylsilylene-ethynylene-1,2-phenylene-ethynylene, [0032]
dimethylsilylene-ethynylene-1,3-phenylene-ethynylene, [0033]
dimethylsilylene-ethynylene-1,4-phenylene-ethynylene, [0034]
dimethylsilylene-ethynylene-1,2-phenylene-ethynylene, [0035]
diethylsilylene-ethynylene-1,3-phenylene-ethynylene, [0036]
phenylsilylene-ethynylene-1,3-phenylene-ethynylene, [0037]
phenylsilylene-ethynylene-1,4-phenylene-ethynylene, [0038]
phenylsilylene-ethynylene-1,2-phenylene-ethynylene, [0039]
diphenylsilylene-ethynylene-1,3-phenylene-ethynylene, [0040]
hexylsilylene-ethynylene-1,3-phenylene-ethynylene, [0041]
vinylsilylene-ethynylene-1,3-phenylene-ethynylene, [0042]
ethynylsilylene-ethynylene-1,3-phenylene-ethynylene, [0043]
2-propenylsilylene-ethynylene-1,3-phenylene-ethynylene, [0044]
2-propynylsilylene-ethynylene-1,3-phenylene-ethynylene, [0045]
trifluoromethylsilylene-ethynylene-1,3-phenylene-ethynylene, [0046]
3,3,3-trifluoropropylsilylene-ethynylene-1,3-phenylene-ethynylene,
[0047] 4-methylphenylsilylene-ethynylene-1,3-phenylene-ethynylene,
[0048] 4-vinylphenylsilylene-ethynylene-1,3-phenylene-ethynylene,
[0049] 4-ethynylphenylsilylene-ethynylene-1,3-phenylene-ethynylene,
[0050] phenylethynylsilylene-ethynylene-1,3-phenylene-ethynylene,
[0051] silylene-ethynylene(5-methyl-1,3-phenylene)ethynylene,
[0052]
phenylsilylene-ethynylene(5-methyl-1,3-phenylene)-ethynylene,
[0053] phenylsilylene-ethynylene(5-silyl-1,3-phenylene)ethynylene,
[0054]
phenylsilylene-ethynylene(5-hydroxy-1,3-phenylene)-ethynylene,
[0055] phenylsilylene-ethynylene-2,7-naphthylene-ethynylene, [0056]
silylene-ethynylene-5,10-anthracenylene-ethynylene, [0057]
phenylsilylene-ethynylene-4,4'-biphenylene-ethynylene, [0058]
phenylsilylene-ethynylene-1,4-phenylenemethylene-1',4'-phenylene-ethynyle-
ne, [0059]
phenylsilylene-ethynylene-1,4-phenylene-2,2-propylidene-1',4'-phenylene-e-
thynylene, [0060]
phenylsilylene-ethynylene-1,4-phenylene-2,2-(1,1,1,3,3,3-hexafluoropropyl-
idene)-1',4'-phenylene-ethynylene, [0061]
phenylsilylene-ethynylene-1,4-phenyleneoxy-1',4'-phenylene-ethynylene,
[0062] phenylsilylene-ethynylene-2,5-pyridilene-ethynylene, [0063]
phenylsilylene-ethynylene-2,5-thiophenylene-ethynylene, [0064]
methylsilylene-ethynylene methylene-ethynylene, [0065]
phenylsilylene-1,4-phenylene(phenylsilylene)ethynylene-1',3'-phenylene-et-
hylynylene, [0066] phenylsilyleneoxy(phenylsilylene)ethynylene,
[0067]
phenylsilyleneoxy(phenylsilylene)ethynylene-1',4'-phenylene-ethynylene,
[0068]
phenylsilyleneimino(phenylsilylene)ethynylene-1',3'-phenylene-eth-
ynylene, [0069]
phenylsilyleneimino(phenylsilylene)ethynylene-1',4'-phenylene-ethynylene,
[0070] silylene-1,3-phenylene-ethynylene, [0071]
silylene-1,4-phenylene-ethynylene, [0072]
silylene-1,2-phenylene-ethynylene, [0073]
phenylsilylene-1,3-phenylene-ethynylene, [0074]
phenylsilylene-1,4-phenylene-ethynylene, [0075]
phenylsilylene-1,2-phenylene-ethynylene, [0076]
diphenylsilylene-1,3-phenylene-ethynylene, [0077]
methylsilylene-1,3-phenylene-ethynylene, [0078]
methylsilylene-1,4-phenylene-ethynylene, [0079]
methylsilylene-1,2-phenylene-ethynylene, [0080]
dimethylsilylene-1,3-phenylene-ethynylene, [0081]
diethylsilylene-1,3-phenylene-ethynylene, [0082]
phenylsilylene-1,3-phenylene-butadiylene, [0083]
diphenylsilylene-1,3-phenylene-butadiylene, [0084]
phenylsilylene-methylene-ethynylene, [0085]
diphenylsilylene-methylene-ethynylene-methylene, [0086]
phenylsilylene-methylene-ethynylene-methylene, [0087]
silylene-1,4-phenylene-ethynylene-1',4'-phenylene, [0088]
methylsilylene-1,4-phenylene-ethynylene-1',4'-phenylene, [0089]
dimethylsilylene-1,4-phenylene-ethynylene-1',4'-phenylene, and
[0090] phenylsilylene-1,4-phenylene-ethynylene-1',4'-phenylene.
[0091] Although there are no specific limitations, the average
molecular weight of the organosilicon polymer of the formula (1) is
preferably 500-500,000. These organosilicon polymers are solid or
liquid at the atmospheric temperature.
[0092] The method for producing the organosilicon polymer of the
formula (1) includes, but are not limited to, dehydrogenation
copolymerization of a diethynyl compound and a silane compound
using a basic oxide, metal hydride, or a metal compound as a
catalyst (Japanese Patent Applications Laid-open No. 7-90085, No.
10-120689, and No. 11-158187), a dehydrogenation polymerization
method of an ethynyl silane compound using a basic oxide as a
catalyst (Japanese Patent Applications Laid-open No. 9-143271), a
method of reacting an organomagnesium reagent with a dichlorosilane
(Japanese Patent Applications Laid-open No. 7-102069 and No.
11-029579), dehydrogenation copolymerization of a diethynyl
compound and a silane compound using a cuprous chloride and
tertiary amine as a catalyst (Hua Qin Liu and John F. Harrod, The
Canadian Journal of Chemistry, Vol. 68, 1100-1105 (1990)), and
dehydrogenation copolymerization of a diethynyl compound and a
silane compound using magnesium oxide as a catalyst (Japanese
Patent Applications Laid-open No. 7-90085 and No. 10-204181).
(B) Organic Solvent
[0093] The film-forming composition of the present invention is a
solution or dispersion of the component (A) in an organic solvent
(B).
[0094] As examples of the organic solvent (B), aliphatic
hydrocarbon solvents such as n-pentane, i-pentane, n-hexane,
i-hexane, n-heptane, i-heptane, 2,2,4-trimethylpentane, n-octane,
i-octane, cyclohexane, and methylcyclohexane; aromatic hydrocarbon
solvents such as benzene, toluene, xylene, ethylbenzene,
trimethylbenzene, methylethylbenzene, n-propylebenzene,
i-propylebenzene, diethylbenzene, i-butylbenzene, triethylbenzene,
di-i-propylbenzene, and n-amylnaphthalene; monohydric alcohols such
as methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol,
sec-butanol, t-butanol, n-pentanol, i-pentanol, 2-methylbutanol,
sec-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol,
2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol,
heptanol-3, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl
alcohol, 2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol,
trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl
alcohol, phenol, cyclohexanol, methylcyclohexanol,
3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol,
diacetone alcohol, and cresol; polyhydric alcohols such as ethylene
glycol, 1,2-propylene glycol, 1,3-butylene glycol, pentanediol-2,4,
2-methylpentanediol-2,4, hexanediol-2,5, heptanediol-2,4,
2-ethylhexanediol-1,3, diethylene glycol, dipropylene glycol,
triethylene glycol, tripropylene glycol, and glycerol; ketones such
as acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl
n-butyl ketone, diethyl ketone, methyl i-butyl ketone, methyl
n-pentyl ketone, ethyl n-butyl ketone, methyl n-hexyl ketone,
di-i-butyl ketone, trimethylenonane, cyclohexanone, 2-hexanone,
methyl cyclohexanone, 2,4-pentane dione, acetonyl acetone,
diacetone alcohol, acetophenone, and fenchone; ethers such as ethyl
ether, i-propyl ether, n-butyl ether, n-hexyl ether, 2-ethylhexyl
ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyl
dioxolane, dioxane, dimethyl dioxane, ethylene glycol monomethyl
ether, ethylene glycol monoethyl ether, ethylene glycol diethyl
ether, ethylene glycol mono-n-butyl ether, ethylene glycol
mono-n-hexyl ether, ethylene glycol monophenyl ether, ethylene
glycol mono-2-ethyl butyl ether, ethylene glycol dibutyl ether,
diethylene glycol monomethyl ether, diethylene glycol monoethyl
ether, diethylene glycol diethyl ether, diethylene glycol
mono-n-butyl ether, diethylene glycol di-n-butyl ether, diethylene
glycol mono-n-hexyl ether, ethoxy triglycol, tetraethylene glycol
di-n-butyl ether, propylene glycol monomethyl ether, propylene
glycol monoethyl ether, propylene glycol monopropyl ether,
propylene glycol monobutyl ether, dipropylene glycol monomethyl
ether, dipropylene glycol monoethyl ether, tripropylene glycol
monomethyl ether, tetrahydrofuran, and 2-methyltetrahydrofuran;
ester solvents such as diethyl carbonate, methyl acetate, ethyl
acetate, .gamma.-butyrolactone, .gamma.-valerolactone, N-propyl
acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate,
sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate,
3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate,
2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate,
methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate,
ethyl acetoacetate, ethylene glycol monomethyl ether acetate,
ethylene glycol monoethyl ether acetate, diethylene glycol
monomethyl ether acetate, diethylene glycol monoethyl ether
acetate, diethylene glycol mono-n-butyl ether acetate, propylene
glycol monomethyl ether acetate, propylene glycol monoethyl ether
acetate, propylene glycol monopropyl ether acetate, propylene
glycol monobutyl ether acetate, dipropylene glycol monomethyl ether
acetate, dipropylene glycol monoethyl ether acetate, glycol
diacetate, methoxy triglycol acetate, ethyl propionate,
n-butylpropionate, i-amyl propionate, diethyl oxalate, di-n-butyl
oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl
lactate, diethyl malonate, dimethyl phthalate, and diethyl
phthalate; nitrogen-containing solvents such as N-methylformamide,
N,N-dimethylformamide, N,N-dimethylformamide, acetamide,
N-methylacetamide, N,N-dimethylacetamide, N-methylpropioneamide,
and N-methylpyrrolidone; and and sulfur-containing solvents such as
dimethyl sulfide, diethyl sulfide, thiophene, tetrahydrothiophene,
dimethylsulfoxide, sulfolane, and 1,3-propanesultone can be
given.
[0095] These solvents may be used either individually or in
combination of two or more.
(C) Other Additives
[0096] The film-forming composition of the present invention may
further comprise other components such as a curing promoter,
colloidal silica, colloidal alumina, organic polymer, surfactant,
silane coupling agent, and triazene compound.
[0097] The stopper for chemical mechanical planarization obtained
in this manner is useful for fabrication of semiconductors such as
LSI, system LSI, DRAM, SDRAM, RDRAM, and D-RDRAM due to its
excellent resistance to CMP processing.
[0098] The polishing method using the stopper for chemical
mechanical planarization of the present invention comprises, for
example, forming the stopper for chemical mechanical planarization
of the present invention on an insulating film on a substrate such
as a silicon wafer, SiO.sub.2 wafer, SiN wafer, SiC wafer, SiCO
wafer, SiCN wafer, or SiCON wafer, producing openings, placing a
metal for wiring on the stopper for chemical mechanical
planarization or filling the openings with the metal for wiring,
and removing unnecessary parts of the metal using a CMP
solution.
[0099] As the insulating film, inorganic insulating films such as a
polysiloxane film, polysilsesquioxane film, CVD-SiO.sub.2 film, and
CVD-carbon dope SiO.sub.2 film can be given.
[0100] To form a stopper for chemical mechanical planarization on
an insulating film, a coating solution of an organic polymer in an
organic solvent is applied to the surface of the insulating film by
a coating method such as spin coating, dipping, roll coating, or
spraying.
[0101] A coated film with a dry thickness of about 0.02-1.5 .mu.m
is obtained by a single application, and about 0.04-3 .mu.m by one
further application. The coated film is then dried at an ordinary
temperature or by heating at about 80-600.degree. C. for 5-240
minutes, thereby forming the stopper for chemical mechanical
planarization. A hot plate, oven, furnace, or the like can be used
for heating the coated film in air, in nitrogen or argon, under
vacuum, or under reduced pressure in which the oxygen concentration
is controlled.
[0102] The stopper for chemical mechanical planarization can also
be formed by irradiating ultraviolet rays or electron beams.
[0103] Next, openings are formed through the two-layer film
consisting of the insulating film and the stopper for chemical
mechanical planarization. A metal is then filled in the openings
and layered over the stopper for chemical mechanical
planarization.
[0104] As the metal layer, a laminate consisting of a first metal
layer of a barrier metal such as titanium nitride (TiN), tantalum
(Ta), or tantalum nitride (TaN) and a second metal layer of copper,
an alloy containing copper as a major component, or a copper
compound is usually used.
[0105] One embodiment of the present invention after forming the
metal film is shown in FIG. 1.
[0106] After forming the metal film, unnecessary metal is removed
by the CMP process to obtain a structure shown in FIG. 2.
[0107] Any known polishing solution can be used for removing the
metal film. The stopper for chemical mechanical planarization of
the present invention is effective in suppressing reduction of
scratching of the insulating film during a polishing operation
using any polishing solution.
EXAMPLES
[0108] The present invention will be described in more detail by
way of examples.
[0109] In the following examples and comparative examples, "parts"
and "%" respectively refer to "parts by weight" and "wt %" unless
otherwise indicated.
[0110] The film-forming compositions in the examples were evaluated
using the following method.
Weight Average Molecular Weight (Mw)
[0111] Mw was measured by gel permeation chromatography (GPC) under
the following conditions. [0112] Samples: 1 g of the sample was
dissolved in 100 cc of tetrahydrofuran. [0113] Standard
polystyrene: Standard polystyrene manufactured by Pressure Chemical
Co. of the U.S. was used. [0114] Apparatus: A high temperature
high-speed gel osmosis chromatogram (Model 150-CALC/GPC.TM.)
manufactured by Waters Co. of the U.S. [0115] Column: SHODEX
A-80M.TM. (length: 50 cm) manufactured by Showa Denko K.K. [0116]
Temperature: 40.degree. C. [0117] Flow rate: 1 cc/min. CMP
Resistivity
[0118] The coated films were polished by the CMP method under the
following conditions. [0119] Slurry: silica-hydrogen peroxide
[0120] Polishing pressure: 400 g/cm.sup.2 [0121] Polishing time:
180 seconds
[0122] After the CMP process, the change in the thickness of coated
films was measured and the outward appearance of the surface was
inspected using a 350,000 lux lamp. The films were rated according
to the following standard. [0123] .largecircle.: The change in the
film thickness was 2% or less and no scars nor peeled parts were
observed on the film surface. [0124] X: The change in the film
thickness was more than 2% less and scars or peeled parts were
observed on the film surface.
Synthesis Example 1
Synthesis of Organosilicon Polymer
[0125] Poly(phenylsilylene-ethynylene-1,3-phenylene-ethynylene) was
dissolved in cyclohexanone to obtain a 15 wt % solution. This
solution is referred to as "Solution (1)".
[0126] The solution (1) was filtered through a Teflon filter with
0.2 .mu.m pore size to measure the relative dielectric constant of
the coating film.
[0127] The relative dielectric constant was 3.0.
Synthesis Example 2
Synthesis of Silicon Polymer
[0128] 77.04 g of methyltrimethoxysilane, 24.05 g of
tetramethoxysilane, and 0.48 g of tetrakis(acetylacetonate)titanium
were dissolved in 290 g of propylene glycol mono-propyl ether in a
separable glass flask. The solution was stirred using a three-one
motor and the temperature of the liquid was stabilized at
60.degree. C. Next, 84 g of ion exchanged water was added to the
solution over one hour. After reacting the mixture for two hours at
60.degree. C., 25 g of acetylacetone was added. The resulting
mixture was reacted for 30 minutes and cooled to room temperature.
149 g of a solution containing methanol and water was removed by
evaporation at 500C This solution is referred to as "Solution
(2)".
[0129] The weight average molecular weight of the resulting
hydrolysis condensate (either the hydrolyzate or its condensate or
both) was 8,900.
Example 1
[0130] The solution (2) obtained in the Synthesis Example 2 was
coated onto an 8-inch silicon wafer by spin coating. The substrate
was sintered for one minute on a hot plate at 100.degree. C. and
for 30 minutes at 420.degree. C. in an oven in nitrogen atmosphere
to obtain a substrate A. The coated film was adjusted to a
thickness of 500 nm.
[0131] The solution (1) obtained in the Synthesis Example 1 was
filtered through a Teflon filter with a pore diameter of 0.2 .mu.m
and coated onto the substrate A by spin coating to obtain a coated
film with a thickness of 100 nm. The substrate was sintered for 2
minutes at 100.degree. C. on a hot plate and for 30 minutes at
420.degree. C. in an oven in a nitrogen atmosphere.
[0132] The CMP resistivity of the substrate was evaluated to
confirm the change in the coated film thickness after the CMP
process was 0.5%. Neither scars nor peelings were observed on the
substrate after the CMP process.
Comparative Example 1
[0133] The solution (2) obtained in the Synthesis Example 2 was
filtered through a Teflon filter with a pore diameter of 0.2 .mu.m
and coated onto the substrate A by spin coating to obtain a coated
film with a thickness of 100 nm. The substrate was sintered for 2
minutes at 100.degree. C. on a hot plate and for 30 minutes at
420.degree. C. in an oven in a nitrogen atmosphere.
[0134] The CMP resistivity of the substrate was evaluated to
confirm the change in the coated film thickness after the CMP
process was 0.8%. Scars and peelings were observed on the substrate
after the CMP process.
[0135] A coating film (interlayer dielectric film material) for
semiconductor with only minimal damages produced by the CMP process
can be obtained by using the stopper for chemical mechanical
planarization made from an organic polymer having a relative
dielectric constant of 4 or less of the present invention.
* * * * *