U.S. patent application number 13/728728 was filed with the patent office on 2013-07-04 for cleaning liquid, and anticorrosive agent.
This patent application is currently assigned to Tokyo Ohka Kogyo Co., Ltd.. The applicant listed for this patent is Tokyo Ohka Kogyo Co., Ltd.. Invention is credited to Takahiro Eto, Takayuki Haraguchi, Tomoya Kumagai, Daijiro Mori, Takuya Ohhashi.
Application Number | 20130172224 13/728728 |
Document ID | / |
Family ID | 48695293 |
Filed Date | 2013-07-04 |
United States Patent
Application |
20130172224 |
Kind Code |
A1 |
Kumagai; Tomoya ; et
al. |
July 4, 2013 |
CLEANING LIQUID, AND ANTICORROSIVE AGENT
Abstract
In a cleaning liquid containing (A) an anticorrosive agent, and
(B) a solvent, a compound represented by the following formula (1):
##STR00001## wherein, R represents a substituent group; m is an
integer of 1 to 3; and n is an integer of 0 to 3, wherein provided
that m is 2 or 3, R may be the same or different; or the following
formula (2): HS--(CH.sub.2).sub.x--OH (2) wherein, x is an integer
of no less than 3, is used as the anticorrosive agent (A).
Inventors: |
Kumagai; Tomoya;
(Kawasaki-shi, JP) ; Ohhashi; Takuya;
(Kawasaki-shi, JP) ; Eto; Takahiro; (Kawasaki-shi,
JP) ; Mori; Daijiro; (Kawasaki-shi, JP) ;
Haraguchi; Takayuki; (Kawasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Tokyo Ohka Kogyo Co., Ltd.; |
Kawasaki-shi |
|
JP |
|
|
Assignee: |
Tokyo Ohka Kogyo Co., Ltd.
Kawasaki-shi
JP
|
Family ID: |
48695293 |
Appl. No.: |
13/728728 |
Filed: |
December 27, 2012 |
Current U.S.
Class: |
510/175 ; 568/62;
568/65; 568/67 |
Current CPC
Class: |
C23F 11/161 20130101;
C23G 1/26 20130101; C23G 1/20 20130101 |
Class at
Publication: |
510/175 ; 568/67;
568/65; 568/62 |
International
Class: |
C23G 1/26 20060101
C23G001/26 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 28, 2011 |
JP |
2011-288930 |
Dec 28, 2011 |
JP |
2011-288931 |
Claims
1. A cleaning liquid comprising (A) a mercapto compound, and (B) a
solvent, wherein the mercapto compound (A) is at least one selected
from compounds represented by the following formula (1):
##STR00004## wherein, R represents a group selected from the group
consisting of a hydroxyl group, an alkyl group having 1 to 4 carbon
atoms, an alkoxy group having 1 to 4 carbon atoms, an alkylthio
group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to
4 carbon atoms, a mercaptoalkyl group having 1 to 4 carbon atoms, a
halogenated alkyl group having 1 to 4 carbon atoms and a halogen
atom; m is an integer of 1 to 3; and n is an integer of 0 to 3,
wherein provided that m is 2 or 3, R may be the same or different;
and the following formula (2): HS--(CH.sub.2).sub.x--OH (2)
wherein, x is an integer of no less than 3.
2. The cleaning liquid according to claim 1, wherein the mercapto
compound (A) is the compound represented by the above formula
(1).
3. The cleaning liquid according to claim 2, wherein the position
of binding of R is a meta- or para-position with respect to the
position at which --(CH.sub.2).sub.n--SH binds.
4. The cleaning liquid according to claim 2, wherein R represents a
hydroxyl group.
5. The cleaning liquid according to claim 1, wherein the mercapto
compound (A) is the compound represented by the above formula
(2).
6. The cleaning liquid according to claim 5, wherein x is an
integer of no less than 3 and no greater than 10.
7. The cleaning liquid according to claim 1, which is used for
cleaning a substrate having a metal layer consisting of copper or a
copper-containing alloy.
8. An anticorrosive agent for copper or a copper-containing alloy,
the anticorrosive agent consisting of a compound represented by the
following formula (1): ##STR00005## wherein, R represents a group
selected from the group consisting of a hydroxyl group, an alkyl
group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4
carbon atoms, an alkylthio group having 1 to 4 carbon atoms, a
hydroxyalkyl group having 1 to 4 carbon atoms, a mercaptoalkyl
group having 1 to 4 carbon atoms, a halogenated alkyl group having
1 to 4 carbon atoms and a halogen atom; m is an integer of 1 to 3;
and n is an integer of 0 to 3, wherein provided that m is 2 or 3, R
may be the same or different, or the following formula (2):
HS--(CH.sub.2).sub.x--OH (2) wherein, x is an integer of no less
than 3.
Description
[0001] This application is based on and claims the benefit of
priority from Japanese Patent Application Nos. 2011-288930 and
2011-288931, filed on 28 Dec. 2011, the contents of which are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a cleaning liquid, and an
anticorrosive agent for copper or a copper-containing metal.
[0004] 2. Related Art
[0005] Semiconductor devices are formed by laminating a metal
wiring layer, a low dielectric layer, an insulating layer or the
like on a substrate such as a silicon wafer, and such semiconductor
devices are manufactured via processing of each of these layers by
a lithography method including carrying out an etching treatment
using a resist pattern as a mask.
[0006] Residual matter derived from a resist film and a temporarily
laminated film (may be also referred to as "sacrificial film") used
in the lithography method, as well as the metal wiring layer and
the low dielectric layer generated in an etching step are
eliminated using a cleaning liquid so as not to be a hindrance for
the semiconductor device, and not to obstruct the following
step(s).
[0007] Furthermore, in recent years, methods of forming wiring have
been adopted in which a damascene method is used, in accordance
with increased density and enhanced integration of semiconductor
devices. According to such a method of forming wiring, copper, a
copper-containing metal or the like that is susceptible to
corrosion is employed as a metal wiring material that constitutes a
metal wiring layer of a semiconductor device.
[0008] In the manufacturing methods of these semiconductor devices,
an alkaline, acidic or neutral cleaning liquid is used according to
the type of the residual matter to be eliminated, whereby corrosion
of copper and copper-containing metals is a problem that results
from the cleaning liquid. The problem of corrosion of the copper
and copper-containing metals is remarkable in the case in which an
acidic or alkaline cleaning liquid is used. Therefore, development
of a cleaning liquid that prevents these copper and
copper-containing metals, etc., from corrosion when cleaning a
substrate has been demanded.
[0009] In order to solve the problem of corrosion of copper and
copper-containing metals, etc., resulting from such a cleaning
liquid, a cleaning liquid was proposed which contains as an
anticorrosive agent, for example, an alcohol having no less than 2
carbon atoms in which at least one mercapto group is included in
the molecule, and a mercapto group and a hydroxyl group are bound
to adjacent carbon atoms (see Patent Document [0010] [Patent
Document 1] Japanese Unexamined Patent Application, Publication No.
2000-273663
SUMMARY OF THE INVENTION
[0011] However, although an effect of preventing corrosion can be
found on metals such as copper to some extent according to the
cleaning liquid containing an anticorrosive agent described in
Patent Document 1, further improvement of the effect of preventing
corrosion has been desired.
[0012] An object of the present invention is to provide a cleaning
liquid, and an anticorrosive agent having a superior anticorrosive
effect on copper or a copper-containing metal.
[0013] The present inventors thoroughly investigated in order to
achieve the object described above, and consequently found that a
mercapto compound having a specific structure has a superior
anticorrosive effect, and is thus useful as an anticorrosive agent.
In addition, the present inventors found that the foregoing
problems can be solved by adding the mercapto compound as an
anticorrosive agent to a cleaning liquid. Accordingly, the present
invention was accomplished. Specifically, the present invention
provides the following.
[0014] A first aspect of the present invention is a cleaning liquid
containing (A) a mercapto compound, and (B) a solvent,
[0015] in which the mercapto compound (A) is at least one selected
from compounds represented by the following formula (1):
##STR00002##
[0016] in the formula (1), R represents a group selected from the
group consisting of a hydroxyl group, an alkyl group having 1 to 4
carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an
alkylthio group having 1 to 4 carbon atoms, a hydroxyalkyl group
having 1 to 4 carbon atoms, a mercaptoalkyl group having 1 to 4
carbon atoms, a halogenated alkyl group having 1 to 4 carbon atoms
and a halogen atom; m is an integer of 1 to 3; and n is an integer
of 0 to 3, wherein provided that m is 2 or 3, R may be the same or
different; and the following formula (2):
HS--(CH.sub.2).sub.x--OH (2)
[0017] in the formula (2), x is an integer of no less than 3.
[0018] A second aspect of the present invention is an anticorrosive
agent for copper or a copper-containing metal, consisting of a
compound represented by the above formula (1) or formula (2).
[0019] According to the present invention, a cleaning liquid, and
an anticorrosive agent having a superior anticorrosive effect on
copper or a copper-containing metal can be provided.
DETAILED DESCRIPTION OF THE INVENTION
Cleaning Liquid
[0020] The cleaning liquid according to the present invention
contains (A) a mercapto compound, and (B) a solvent. The mercapto
compound (A) is at least one compound selected from an aromatic
mercapto compound represented by the formula (1), and a linear
mercapto alcohol compound represented by the formula (2) described
below.
(A) Mercapto Compound
[0021] The cleaning liquid is used for cleaning an object to be
cleaned such as, for example, substrates and the like having a
wiring formed thereon with copper, a copper-containing metal or the
like. By thus cleaning, residual matter and the like attached to
the surface of the object to be cleaned, derived from a resist film
and a temporarily laminated film, and from the metal wiring layer
and the low dielectric layer generated in an etching step are
eliminated from the surface of the object to be cleaned. In the
case in which the cleaning liquid contains as the mercapto compound
(A), one or more compounds selected from a compound represented by
the following formula (1), and a linear mercapto alcohol compound
represented by the following formula (2), corrosion of wiring
consisting of copper or a copper-containing metal can be inhibited,
thereby enabling the suppression of changes in a value of
resistance during cleaning, and occurrences of breaking of the
wire.
##STR00003##
[0022] In the formula (1), R represents a group selected from the
group consisting of a hydroxyl group, an alkyl group having 1 to 4
carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an
alkylthio group having 1 to 4 carbon atoms, a hydroxyalkyl group
having 1 to 4 carbon atoms, a mercaptoalkyl group having 1 to 4
carbon atoms, a halogenated alkyl group having 1 to 4 carbon atoms
and a halogen atom; m is an integer of 1 to 3; and n is an integer
of 0 to 3, wherein provided that m is 2 or 3, R may be the same or
different.
HS--(CH.sub.2).sub.x--OH (2)
[0023] In the formula (1), x is an integer of no less than 3.
[0024] Specific examples of the case in which R represents an alkyl
group having 1 to 4 carbon atoms which may have a hydroxyl group in
the formula (1) include a methyl group, an ethyl group, a n-propyl
group, an iso-propyl group, a n-butyl group, an iso-butyl group, a
sec-butyl group, and a tert-butyl group. Among these alkyl groups,
a methyl group, a hydroxymethyl group or an ethyl group is
preferred since suitable solubility in a solvent can be attained,
and a methyl group or a hydroxymethyl group is more preferred since
the anticorrosive effect is further improved.
[0025] Specific examples of the case in which R represents an
alkoxy group having 1 to 4 carbon atoms in the formula (1) include
a methoxy group, an ethoxy group, a n-propyloxy group, an
iso-propyloxy group, a n-butyloxy group, an iso-butyloxy group, a
sec-butyloxy group, and a tert-butyloxy group. Among these alkoxy
groups, a methoxy group or an ethoxy group is preferred since
suitable solubility in a solvent can be attained, and a methoxy
group is more preferred since the anticorrosive effect is further
improved.
[0026] Specific examples of the case in which R represents an
alkylthio group having 1 to 4 carbon atoms in the formula (1)
include a methylthio group, an ethylthio group, a n-propylthio
group, an iso-propylthio group, a n-butylthio group, an
iso-butylthio group, a sec-butylthio group, and a tert-butylthio
group. Among these alkylthio groups, a methylthio group or an
ethylthio group is preferred since suitable solubility in a solvent
can be attained, and a methylthio group is more preferred since the
anticorrosive effect is further improved.
[0027] Specific examples of the case in which R represents a
hydroxyalkyl group having 1 to 4 carbon atoms in the formula (1)
include a hydroxymethyl group, a 2-hydroxyethyl group, a
1-hydroxyethyl group, a 3-hydroxy-n-propyl group, a
4-hydroxy-n-butyl group, and the like. Among these hydroxyalkyl
groups, a hydroxymethyl group, a 2-hydroxyethyl group or a
1-hydroxyethyl group is preferred since suitable solubility in a
solvent can be attained, and a hydroxymethyl group is more
preferred since the anticorrosive effect is further improved.
[0028] Specific examples of the case in which R represents a
mercaptoalkyl group having 1 to 4 carbon atoms in the formula (1)
include a mercaptomethyl group, a 2-mercaptoethyl group, a
1-mercaptoethyl group, a 3-mercapto-n-propyl group, a
4-mercapto-n-butyl group, and the like. Among these mercaptoalkyl
groups, a mercaptomethyl group, a 2-mercaptoethyl group or a
1-mercaptoethyl group is preferred since suitable solubility in a
solvent can be attained, and a mercaptomethyl group is more
preferred since the anticorrosive effect is further improved.
[0029] In the case in which R represents a halogenated alkyl group
having 1 to 4 carbon atoms in the formula (1), examples of the
halogen atom included in the halogenated alkyl group include
fluorine, chlorine, bromine, iodine, and the like. Specific
examples of the case in which R represents a halogenated alkyl
group having 1 to 4 carbon atoms include a chloromethyl group, a
bromomethyl group, an iodomethyl group, a fluoromethyl group, a
dichloromethyl group, a dibromomethyl group, a difluoromethyl
group, a trichloromethyl group, a tribromomethyl group, a
trifluoromethyl group, a 2-chloroethyl group, a 2-bromoethyl group,
a 2-fluoroethyl group, a 1,2-dichloroethyl group, a
2,2-difluoroethyl group, a 1-chloro-2-fluoroethyl group, a
3-chloro-n-propyl group, a 3-bromo-n-propyl group, a
3-fluoro-n-propyl group, a 4-chloro-n-butyl group, and the like.
Among these halogenated alkyl groups, a chloromethyl group, a
bromomethyl group, an iodomethyl group, a fluoromethyl group, a
dichloromethyl group, a dibromomethyl group, a difluoromethyl
group, a trichloromethyl group, a tribromomethyl group or a
trifluoromethyl group is preferred, and a chloromethyl group, a
dichloromethyl group, a trichloromethyl group or a trifluoromethyl
group is more preferred since the anticorrosive effect is further
improved.
[0030] In the case in which R represents a halogen atom in the
formula (1), specific examples of the halogen atom include
fluorine, chlorine, bromine, and iodine.
[0031] In the formula (1), m is an integer of 1 to 3, and more
preferably 1. Provided that m is 2 or 3, R may be the same or
different.
[0032] In the compound represented by the formula (1), the position
of substitution with R on the benzene ring is not particularly
limited. Since a superior anticorrosive effect is likely to be
achieved, the position of substitution with R on the benzene ring
is preferably a meta- or para-position with respect to the position
at which --(CH.sub.2).sub.n--SH binds.
[0033] As the compound represented by the formula (1), due to
superior anticorrosive properties for copper or a copper-containing
metal, and superior stability in the cleaning liquid, a compound
having at least one group selected from the group consisting of an
alkyl group, a hydroxyalkyl group and a mercaptoalkyl group as R is
preferred, and a compound having one group selected from the group
consisting of an alkyl group, a hydroxyalkyl group and a
mercaptoalkyl group as R is more preferred. In the case in which
the compound represented by the formula (1) has one group selected
from the group consisting of an alkyl group, a hydroxyalkyl group
and a mercaptoalkyl group as R, the position of substitution with
an alkyl group, a hydroxyalkyl group, or a mercaptoalkyl group on
the benzene ring is preferably a meta- or para-position and more
preferably a para-position with respect to the position at which
--(CH.sub.2).sub.n--SH binds.
[0034] In the formula (1), n is an integer of 0 to 3. Due to ease
in preparation and availability of the compound n is preferably 0
or 1, and more preferably 0.
[0035] Specific examples of the compound represented by the formula
(1) include p-mercaptophenol, p-thiocresol, m-thiocresol,
4-(methylthio)benzenethiol, 4-methoxybenzenethiol,
3-methoxybenzenethiol, 4-ethoxybenzenethiol, 4-isopropyloxy
benzenethiol, 4-tert-butoxybenzenethiol, 3,4-dimethoxy
benzenethiol, 3,4,5-trimethoxybenzenethiol, 4-ethylbenzenethiol,
4-isopropyl benzenethiol, 4-n-butylbenzenethiol,
4-tert-butylbenzenethiol, 3-ethylbenzenethiol, 3-isopropyl
benzenethiol, 3-n-butylbenzenethiol, 3-tert-butylbenzenethiol,
3,5-dimethyl benzenethiol, 3,4-dimethyl benzenethiol,
3-tert-butyl-4-methylbenzenethiol, 3-tert-4-methylbenzenethiol,
3-tert-butyl-5-methylbenzenethiol,
4-tert-butyl-3-methylbenzenethiol, 4-mercaptobenzyl alcohol,
3-mercaptobenzyl alcohol, 4-(mercaptomethyl)phenol,
3-(mercaptomethyl)phenol, 4-fluorobenzenethiol,
3-fluorobenzenethiol, 4-chlorobenzenethiol, 3-chlorobenzenethiol,
4-bromobenzenethiol, 4-iodobenzenethiol, 3-bromobenzenethiol,
3,4-dichlorobenzenethiol, 3,5-dichlorobenzenethiol,
3,4-difluorobenzenethiol, 3,5-difluorobenzenethiol,
4-mercaptocatechol, 2,6-di-tert-butyl-4-mercaptophenol,
3,5-di-tert-butyl-4-methoxybenzenethiol,
4-bromo-3-methylbenzenethiol, 4-(trifluoromethyl)benzenethiol,
3-(trifluoromethyl)benzenethiol,
3,5-bis(trifluoromethyl)benzenethiol, 4-methylthiobenzenethiol,
4-ethylthiobenzenethiol, 4-n-butylthiobenzenethiol, and
4-tert-butylthiobenzenethiol, and the like. Among these compounds,
due to high anticorrosive effects on copper and copper-containing
metals, and favorable availability, p-mercaptophenol, p-thiocresol,
m-thiocresol, 4-(methylthio)benzenethiol, 4-methoxybenzenethiol,
4-ethylbenzenethiol, 4-isopropyl benzenethiol,
4-fluorobenzenethiol, 4-chlorobenzenethiol, and 4-bromobenzenethiol
are more preferred. In addition, due to high anticorrosive effects
on copper and copper-containing metals, and superior stability in
the cleaning liquid, 4-mercaptobenzyl alcohol and
4-(mercaptomethyl)phenol are also preferred.
[0036] In the formula (2), x is an integer of no less than 3, and
the upper limit thereof is not particularly limited within the
range not resulting in impairment of the object of the present
invention. In light of the ability to favorably inhibit corrosion
of copper and copper-containing metals resulting from the cleaning
liquid, x is preferably an integer of no less than 3 and no greater
than 10, and more preferably an integer of no less than 3 and no
greater than 9. When the compound in which x falls within such a
range is used as an anticorrosive agent, the anticorrosive agent is
likely to be dissolved in the cleaning liquid, whereby a favorable
anticorrosive effect can be readily achieved. Also, in this case,
when the object to be cleaned after cleaning is rinsed with water,
deposition of the compound represented by the formula (2) as an
anticorrosive agent can be suppressed.
[0037] Although the compound in which x is an integer of less than
3 is readily dissolved in the cleaning liquid, it exhibits an
inferior anticorrosive effect. Although the compound in which x is
greater than 10 exhibits a favorable anticorrosive effect, when a
cleaning liquid containing such a compound is used, rinsing with
water after cleaning may cause deposition on the surface of the
object to be cleaned. Therefore, when a cleaning liquid containing
the compound in which x is an integer of greater than 10 is used,
the cleaning is preferably followed by rinsing with an organic
solvent, and then rinsing with water as needed.
[0038] Suitable examples of the compound represented by the formula
(2) include:
[0039] HS--(CH.sub.2).sub.3--OH;
[0040] HS--(CH.sub.2).sub.4--OH;
[0041] HS--(CH.sub.2).sub.5--OH;
[0042] HS--(CH.sub.2).sub.6--OH;
[0043] HS--(CH.sub.2).sub.7--OH;
[0044] HS--(CH.sub.2).sub.8--OH;
[0045] HS--(CH.sub.2).sub.9--OH; and
[0046] HS--(CH.sub.2).sub.10--OH.
[0047] The content of the mercapto compound (A) in the cleaning
liquid is not particularly limited as long as it does not inhibit
the cleaning effect of the cleaning liquid, and the mercapto
compound (A) can be homogenously dissolved in the cleaning liquid.
The content of the mercapto compound (A) in the cleaning liquid is
preferably 0.05 to 5.0% by mass, and more preferably 0.1 to 1.0% by
mass with respect to the mass of the cleaning liquid. When the
mercapto compound (A) is added to the cleaning liquid in an amount
falling within such a range, in the case in which the object to be
cleaned after cleaning with the cleaning liquid is rinsed with
water or the like, deposition of the mercapto compound (A) is
readily suppressed, while achieving favorable anticorrosive effects
of metals. It is to be noted that two or more types of the mercapto
compound (A) may be used in combination in the cleaning liquid.
(B) Solvent
[0048] The cleaning liquid contains (B) a solvent that dissolves
the mercapto compound (A), and (C) an alkaline compound or acidic
compound as well as (D) other additives described later. The
solvent is not particularly limited as long as it can homogenously
dissolve the components contained in the cleaning liquid, and any
one of water, an organic solvent, and an aqueous solution of an
organic solvent may be used.
[0049] Although the organic solvent may be either a water soluble
organic solvent or a hydrophobic organic solvent, a water soluble
organic solvent is preferred. The organic solvent included in the
solvent is preferably water soluble, since the cleaning liquid
remaining on the surface of the object to be cleaned can be easily
eliminated by rinsing the object to be cleaned with water.
[0050] Suitable examples of the water soluble organic solvent
include sulfoxides such as dimethyl sulfoxide; sulfones such as
dimethyl sulfone, diethyl sulfone, bis(2-hydroxyethyl)sulfone, and
tetramethylene sulfone; amides such as N,N-dimethyl formamide,
N-methylformamide, N,N-dimethylacetamide, N-methylacetamide, and
N,N-diethyl acetamide; lactams such as N-methyl-2-pyrrolidone,
N-ethyl-2-pyrrolidone, N-hydroxymethyl-2-pyrrolidone, and
N-hydroxyethyl-2-pyrrolidone; lactones such as
.beta.-propiolactone, .gamma.-butyrolactone, .gamma.-valerolactone,
.delta.-valerolactone, .gamma.-caprolactone, and .di-elect
cons.-caprolactone; imidazolidinones such as
1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, and
1,3-diisopropyl-2-imidazolidinone; polyhydric alcohols and
derivatives thereof such as ethylene glycol, ethylene glycol
monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol
monobutyl ether, ethylene glycol monoacetate, ethylene glycol
monomethyl ether acetate, ethylene glycol monoethyl ether acetate,
diethylene glycol, diethylene glycol monoacetate, diethylene glycol
monomethyl ether, diethylene glycol monoethyl ether, diethylene
glycol monobutyl ether, propylene glycol, propylene glycol
monomethyl ether, propylene glycol monoethyl ether, propylene
glycol monopropyl ether, dipropylene glycol monomethyl ether,
glycerin, 1,2-butylene glycol, 1,3-butylene glycol, and
2,3-butylene glycol; alkanolamines such as monoethanolamine,
diethanolamine, triethanolamine, 2-(2-aminoethoxy)ethanol,
N,N-dimethyl ethanolamine, N,N-diethyl ethanolamine,
N,N-dibutylethanolamine, N-methylethanolamine, N-ethylethanolamine,
N-butylethanolamine, N-methyldiethanolamine, monoisopropanolamine,
diisopropanolamine, and triisopropanolamine.
[0051] Among these water soluble organic solvents, dimethyl
sulfoxide, propylene glycol monomethyl ether, propylene glycol
monoethyl ether, propylene glycol monopropyl ether, diethylene
glycol monoethyl ether, and diethylene glycol monobutyl ether are
more preferred.
[0052] When the solvent contained in the cleaning liquid includes a
water soluble organic solvent, both hydrophilic residues and
hydrophobic residues attached to the object to be cleaned can be
easily eliminated. Therefore, it is preferred to use a water
soluble organic solvent in combination with water.
[0053] The content of the solvent in the cleaning liquid is
determined as a matter of course, depending on the used amount of
the components dissolved in the cleaning liquid. When the solvent
contained in the cleaning liquid includes water and a water soluble
organic solvent, the content of the water soluble organic solvent
in the cleaning liquid is preferably 10 to 90% by mass, and more
preferably 20 to 80% by mass. In the case in which the cleaning
liquid does not contain water, the content of the aqueous organic
solvent in the cleaning liquid is preferably 50 to 99% by mass, and
more preferably 75 to 95% by mass.
(C) Alkaline Compound, or Acidic Compound
[0054] As the cleaning liquid, any of an alkaline cleaning liquid,
an acidic cleaning liquid, and a neutral cleaning liquid may be
used, which may be appropriately selected according to the type of
the residual matter to be eliminated attached to the object to be
cleaned. Of these cleaning liquids, an alkaline, or acidic cleaning
liquid is preferred due to having a superior cleaning effect. When
the cleaning liquid is an alkaline, or acidic cleaning liquid, an
alkaline compound, or an acidic compound is blended into the
cleaning liquid. However, with respect to the alkaline cleaning
liquid, it is not always necessary to blend an alkaline compound
into the cleaning liquid when the solvent contains an alkanolamine
that is a basic compound.
[0055] When the cleaning liquid is alkaline, the alkaline compound
blended into the cleaning liquid is appropriately selected from an
organic or an inorganic alkaline compound. As the organic alkaline
compound, a variety of basic nitrogen-containing organic compounds
may be used. Among the basic nitrogen-containing organic compounds,
a quaternary ammonium hydroxide is preferred. Suitable examples of
a quaternary ammonium hydroxide include tetramethylammonium
hydroxide, tetraethylammonium hydroxide, tetrapropylammonium
hydroxide, tetrabutylammonium hydroxide, ethyltrimethylammonium
hydroxide, dimethyl diethylammonium hydroxide,
methyltriethylammonium hydroxide, methyltripropylammonium
hydroxide, methyltributylammonium hydroxide,
benzyltrimethylammonium hydroxide, and
(2-hydroxyethyl)trimethylammonium hydroxide, and the like. Among
these quaternary ammonium hydroxides, since a favorable cleaning
effect of the cleaning liquid can be achieved, tetramethylammonium
hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium
hydroxide, benzyltrimethylammonium hydroxide and tetraethylammonium
hydroxide are preferred, and tetramethylammonium hydroxide or
tetrabutylammonium hydroxide is more preferred. The organic
alkaline compounds may be used in combination of two or more
thereof.
[0056] The amount of the organic alkaline compound blended into the
cleaning liquid may vary depending on the basicity of the compound,
and typically, the amount is preferably 1 to 20% by mass, and more
preferably 2 to 15% by mass with respect to the mass of the
cleaning liquid.
[0057] The inorganic alkaline compound is not particularly limited
within the range that does not hamper the object of the present
invention, and a variety of compounds may be used. Suitable
examples of the inorganic alkaline compound include alkali metal
hydroxides such as sodium hydroxide, potassium hydroxide, and
rubidium hydroxide. The inorganic alkaline compounds may be used in
combination of two or more thereof.
[0058] The amount of the inorganic alkaline compound blended into
the cleaning liquid may vary depending on the basicity of the
compound, and typically, the amount is preferably 0.1 ppm by mass
to 1% by mass, and more preferably 1 ppm by mass to 0.5% by mass
with respect to the mass of the cleaning liquid.
[0059] When the cleaning liquid is acidic, the acidic compound
blended into the cleaning liquid is appropriately selected from
among protonic acids within the range that does not hamper the
object of the present invention. Specific examples of a suitable
acidic compound include protonic acids such as hydrochloric acid,
hydrofluoric acid, sulfuric acid, nitric acid, formic acid, acetic
acid, propionic acid, butyric acid, isobutyric acid, valeric acid,
isovaleric acid, lactic acid, oxalic acid, malonic acid, succinic
acid, glutaric acid, adipic acid, citric acid, glycolic acid,
diglycolic acid, phosphoric acid, methanesulfonic acid,
trifluoroacetic acid, and trifluoromethane sulfonic acid. The
acidic compound may be used in combination of two or more
thereof.
[0060] The amount of the acidic compound blended into the cleaning
liquid may vary depending on the acidity of the compound, and
typically, the amount is preferably 0.1 to 20% by mass, more
preferably 0.5 to 15% by mass with respect to the mass of the
cleaning liquid. 1.0 to 10% by mass is still more preferable.
(D) Other Additives
[0061] The cleaning liquid may contain in addition to the mercapto
compound (A), and the alkaline or acidic compound, a variety of
additives that may be commonly blended into cleaning liquids,
within a range which does not hamper the object of the present
invention. Suitable examples of other additives which may be
blended into the cleaning liquid include surfactants, antioxidants,
antiseptic agents, and the like.
[0062] The amount of the other additive used may be appropriately
determined according to the type of the additive. The other
additive is blended into the cleaning liquid in an amount falling
within the range commonly used in cleaning liquids.
Cleaning Method of the Object to be Cleaned
[0063] The object to be cleaned which is cleaned by the cleaning
liquid containing the mercapto compound (A) is not particularly
limited. When the object to be cleaned is a substrate having a
metal layer consisting of copper or a copper-containing alloy,
corrosion of the metal layer can be favorably inhibited even in the
case in which the substrate is cleaned with a cleaning liquid
containing the mercapto compound (A). As suitable examples of
preferable substrate having a metal layer consisting of copper or a
copper-containing alloy, substrates produced by laminating a metal
wiring layer, a low dielectric layer, an insulating layer, etc., on
a substrate such as a silicon wafer to form a semiconductor device
are preferable.
[0064] The cleaning method of the object to be cleaned is not
particularly limited as long as it is a commonly employed method.
Specifically, the cleaning liquid is brought into contact with the
object to be cleaned for 1 to 40 min to carry out the treatment
using, for example, an immersion method, a puddling method, a
showering method or the like. The cleaning is usually carried out
at room temperature; however, the temperature of the cleaning
liquid may be elevated to about 85.degree. C. in order to improve
the cleaning effect.
EXAMPLES
[0065] Hereinafter, the present invention will be explained in more
detail by way of Examples, but the present invention is not limited
to these Examples.
Examples 1 to 10, and Comparative Examples 1 to 4
[0066] The compounds shown in Table 2 were used as anticorrosive
agents. Each component contained in the cleaning liquid was mixed
at each percentage shown in Table 1 below to prepare a homogenously
dissolved cleaning liquid. It is to be noted that in Comparative
Example 1, the content of water in the cleaning liquid was 50.30%
by mass since the anticorrosive agent was not used.
TABLE-US-00001 TABLE 1 Composition (% by mass) Anticorrosive agent
0.30 Dimethyl sulfoxide 25.02 Diethylene glycol monobutyl ether
16.68 Water 50.00 Tetramethylammonium hydroxide 8.00
[0067] Using the cleaning liquid thus obtained, an anticorrosion
test was performed according to the method described below. The
amount of corrosion of the copper film (nm) found when the
anticorrosion test was performed using each cleaning liquid of the
Examples and Comparative Examples is shown in Table 2.
Anticorrosion Test Method
[0068] A test piece cut out to give a size of 4 cm.times.2 cm from
a silicon substrate provided with a copper film having a film
thickness of 30 nm formed on the surface thereof by a sputtering
method was used as an object to be cleaned. As the test vessel, a
100 ml glass beaker was used. The test piece was leaned against the
inner wall of the beaker such that the short side of the test piece
was in contact with the bottom face of the beaker, and the test was
performed. After each cleaning liquid of the Examples, and
Comparative Examples which had been warmed to 50.degree. C. was
slowly poured into a beaker in which the test piece had been
placed, the test piece was immersed in the cleaning liquid for 10
min while the temperature of the cleaning liquid was maintained at
50.degree. C. During the immersion, the cleaning liquid was stirred
by a stirring device equipped with a single propeller blade, at a
rotation frequency of 200 rpm. After completing the immersion, the
test piece was pulled up from the cleaning liquid, the surface of
the test piece was rinsed with water, and then, nitrogen was
sprayed on the surface of the test piece to dry the test piece. The
values of the surface resistance of the surface of the test piece
on which the copper film was formed after drying were measured by a
VR-70 (manufactured by Kokusai Denki Kabushiki Kaisha). The amount
of corrosion of the copper film was calculated from the value of
surface resistance.
TABLE-US-00002 TABLE 2 Amount of corrosion of the Anticorrosive
agent cupper film (nm) Example 1 p-Mercaptophenol 0.09 Example 2
p-Thiocresol 0.22 Example 3 m-Thiocresol 0.18 Example 4
4-(Methylthio) benzenethiol 0.21 Example 5 4-Methoxybenzenethiol
0.37 Example 6 4-Ethylbenzenethiol 0.19 Example 7
4-Isopropylbenzenethiol 0.17 Example 8 4-Fluorobenzenethiol 0.22
Example 9 4-Chlorobenzenethiol 0.13 Example 10 4-Bromobenzenethiol
0.04 Comparative example 1 None No less than 30.00 Comparative
example 2 Thioglycerol 1.71 Comparative example 3 Benzylmercaptan
1.01 Comparative example 4 Thiophenol 2.04
[0069] According to Examples 1 to 10, and Comparative Example 1, it
can be understood that the cleaning liquid containing the aromatic
mercapto compound represented by the formula (1) as an
anticorrosive agent can extremely favorably inhibit corrosion of
copper in the cleaning step. On the other hand, according to
Comparative Examples 2 to 4, it can be understood that even in the
case of a compound having a mercapto group, the cleaning liquid in
which a compound other than that represented by the formula (1) or
formula (2) was used as an anticorrosive agent results in corrosion
of the copper film to some extent although the corrosion of the
copper film is inhibited.
Examples 11 and 12
[0070] The cleaning liquid of Example 11 was prepared similarly to
Example 2 except that the content of p-thiocresol was changed from
0.30% by mass to 0.10% by mass, and that the content of water was
changed from 50.00% by mass to 50.20% by mass. In addition, the
cleaning liquid of Example 12 was prepared similarly to Example 2
except that the content of p-thiocresol was changed from 0.30% by
mass to 0.70% by mass, and that the content of water was changed
from 50.00% by mass to 49.60% by mass.
[0071] When the anticorrosion test was performed using the cleaning
liquids of Examples 11 and 12 similarly to Example 2, the amount of
corrosion of the copper film was 0.35 nm in the case of the
cleaning liquid of Example 11, whereas the amount of corrosion of
the copper film was 0.15 nm in the case of the cleaning liquid of
Example 12.
[0072] According to Example 2 and Example 11, it can be understood
that when the content of the anticorrosive agent in the cleaning
liquid was lowered to about 0.10% by mass, superior anticorrosive
effect can be maintained although the amount of corrosion of the
copper film somewhat increases. Also, according to Example 2 and
Example 12, it can be understood that an increase in the content of
the anticorrosive agent in the cleaning liquid enables the
anticorrosive effect of the cleaning liquid to be further
improved.
Example 13, and Comparative Example 5
[0073] The compounds shown in Table 4 were used as anticorrosive
agents. Each component contained in the cleaning liquid was mixed
at each percentage shown in Table 3 below to prepare a
homogeneously dissolved cleaning liquid. It is to be noted that in
Comparative Example 5, the content of water in the cleaning liquid
was 50.30% by mass since the anticorrosive agent was not used.
TABLE-US-00003 TABLE 3 Composition (% by mass) Anticorrosive agent
0.30 Dimethyl sulfoxide 29.52 Diethylene glycol monobutyl ether
19.68 Water 50.00 Potassium hydroxide 0.5
TABLE-US-00004 TABLE 4 Amount of corrosion of the cupper film
Anticorrosive agent (nm) Example 13 p-thiocresol 0.21 Comparative
example 5 None No less than 30.00
[0074] According to Example 2 and Example 13, and Comparative
Example 5, it can be understood that in the alkaline cleaning
liquids, irrespective of the type of alkaline substance included in
the cleaning liquid, use of the aromatic mercapto compound
represented by the formula (1) as an anticorrosive agent enables
corrosion of copper to be extremely favorably inhibited in the
cleaning step.
Example 14 and Comparative Example 6
[0075] The compounds shown in Table 6 were used as anticorrosive
agents. Each component contained in the cleaning liquid was mixed
at each percentage shown in Table 5 below to prepare a
homogeneously dissolved cleaning liquid. It is to be noted that in
Comparative Example 6, the content of water in the cleaning liquid
was 50.30% by mass since the anticorrosive agent was not used.
TABLE-US-00005 TABLE 5 Composition (% by mass) Anticorrosive agent
0.30 Dimethyl sulfoxide 23.82 Diethylene glycol monobutyl ether
15.88 Water 50.00 Malonic acid 10.00
TABLE-US-00006 TABLE 6 Amount of corrosion of the cupper film
Anticorrosive agent (nm) Example 14 p-thiocresol 0.50 Comparative
example 6 None No less than 30.00
[0076] According to Example 14 and Comparative Example 6, it can be
understood that also in acidic cleaning liquids, use of the
aromatic mercapto compound represented by the formula (1) as an
anticorrosive agent enables corrosion of copper to be extremely
favorably inhibited in the cleaning step.
Examples 15 to 17, and Comparative Example 7
[0077] The compounds shown in Table 8 were used as anticorrosive
agents. Each component contained in the cleaning liquid was mixed
at each percentage shown in Table 7 below to prepare a
homogeneously dissolved cleaning liquid. It is to be noted that for
comparison with Examples 15 to 17, the results of Comparative
Examples 1 and 2 are shown together in Table 8.
TABLE-US-00007 TABLE 7 Composition (% by mass) Anticorrosive agent
0.30 Dimethyl sulfoxide 25.02 Diethylene glycol monobutyl ether
16.68 Water 50.00 Tetramethylammonium hydroxide 8.00
[0078] Using the cleaning liquid thus obtained, an anticorrosion
test was performed according to a similar method to Example 1. The
amount of corrosion of the copper film (nm) found when the
anticorrosion test was performed using each cleaning liquid of the
Examples and Comparative Examples is shown in Table 8.
TABLE-US-00008 TABLE 8 Amount of corrosion of the cupper film
Anticorrosive agent (nm) Example 15 HS--(HC.sub.2).sub.3--OH 0.80
Example 16 HS--(CH.sub.2).sub.6--OH 0.72 Example 17
HS--(CH.sub.2).sub.9--OH 0.05 Comparative example 1 None No less
than 30.00 Comparative example 2 Thioglycerol 1.71 Comparative
example 7 Mercaptoethanol 1.36
[0079] According to Examples 15 to 17, and Comparative Example 1,
it can be understood that the cleaning liquid containing the linear
mercapto alcohol compound represented by the formula (2) as an
anticorrosive agent can extremely favorably inhibit corrosion of
copper in the cleaning step. On the other hand, according to
Comparative Examples 2 and 7, it can be understood that even in the
case of a compound having a mercapto group, the cleaning liquid in
which a compound other than that represented by the formula (1) or
formula (2) was used as an anticorrosive agent results in corrosion
of the copper film to some extent although the corrosion of the
copper film is inhibited.
Examples 18 and 19
[0080] The cleaning liquid of Example 18 was prepared similarly to
Example 16 except that the content of mercaptohexanol
(HS--(CH.sub.2).sub.6--OH) was changed from 0.30% by mass to 0.10%
by mass, and that the content of water was changed from 50.00% by
mass to 50.20% by mass. In addition, the cleaning liquid of Example
19 was prepared similarly to Example 16 except that the content of
mercaptohexanol was changed from 0.30% by mass to 0.70% by mass,
and that the content of water was changed from 50.00% by mass to
49.60% by mass.
[0081] When the anticorrosion test was performed using the cleaning
liquids of Examples 18 and 19 similarly to Example 1, the amount of
corrosion of the copper film was 0.85 nm in the case of the
cleaning liquid of Example 18, whereas the amount of corrosion of
the copper film was 0.50 nm in the case of the cleaning liquid of
Example 19.
[0082] According to Example 16 and Example 18, it can be understood
that when the content of the linear mercapto alcohol compound in
the cleaning liquid was lowered to about 0.10% by mass, superior
anticorrosive effect can be maintained although the amount of
corrosion of the copper film somewhat increases. Also, according to
Example 16 and Example 19, it can be understood that an increase in
the content of the linear mercapto alcohol compound in the cleaning
liquid enables the anticorrosive effect of the cleaning liquid to
be further improved.
Example 20
[0083] The compound shown in Table 10 was used as an anticorrosive
agent. Each component contained in the cleaning liquid was mixed at
each percentage shown in Table 9 below to prepare a homogeneously
dissolved cleaning liquid. It is to be noted that for comparison,
the results of Comparative Example 5 are shown together with those
of Example 20 in Table 10.
TABLE-US-00009 TABLE 9 Composition (% by mass) Anticorrosive agent
0.30 Dimethyl sulfoxide 29.52 Diethylene glycol monobutyl ether
19.68 Water 50.00 Potassium hydroxide 0.5
TABLE-US-00010 TABLE 10 Amount of corrosion of the cupper film
Anticorrosive agent (nm) Example 20 HS--(CH.sub.2).sub.6--OH 0.62
Comparative example 5 None No less than 30.00
[0084] According to Example 16 and Example 20, and Comparative
Example 5, it can be understood that in the alkaline cleaning
liquids, irrespective of the type of alkaline substance included in
the cleaning liquid, use of the linear mercapto alcohol compound
represented by the formula (2) as an anticorrosive agent enables
corrosion of copper to be extremely favorably inhibited in the
cleaning step.
Example 21
[0085] The compound shown in Table 12 was used as an anticorrosive
agent. Each component contained in the cleaning liquid was mixed at
each percentage shown in Table 11 below to prepare a homogeneously
dissolved cleaning liquid. It is to be noted that for comparison,
the results of Comparative Example 6 are shown together with those
of Example 21 in Table 12.
TABLE-US-00011 TABLE 11 Composition (% by mass) Anticorrosive agent
0.30 Dimethyl sulfoxide 23.82 Diethylene glycol monobutyl ether
15.88 Water 50.00 Malonic acid 10.00
TABLE-US-00012 TABLE 12 Amount of corrosion of the cupper film
Anticorrosive agent (nm) Example 21 HS--(CH.sub.2).sub.6--OH 0.75
Comparative example 6 None No less than 30.00
[0086] According to Example 21 and Comparative Example 6, it can be
understood that also in the acidic cleaning liquid, use of the
linear mercapto compound represented by the formula (2) as an
anticorrosive agent enables corrosion of copper to be extremely
favorably inhibited in the cleaning step.
* * * * *