U.S. patent application number 13/091732 was filed with the patent office on 2011-08-11 for post-cmp treating liquid and manufacturing method of semiconductor device using the same.
Invention is credited to Nobuyuki KURASHIMA, Gaku Minamihaba, Yoshikuni Tateyama, Hiroyuki Yano.
Application Number | 20110195888 13/091732 |
Document ID | / |
Family ID | 39740226 |
Filed Date | 2011-08-11 |
United States Patent
Application |
20110195888 |
Kind Code |
A1 |
KURASHIMA; Nobuyuki ; et
al. |
August 11, 2011 |
POST-CMP TREATING LIQUID AND MANUFACTURING METHOD OF SEMICONDUCTOR
DEVICE USING THE SAME
Abstract
Post-CMP treating liquids are provided, one of which includes
water, an amphoteric surfactant, an anionic surfactant, a
complexing agent, resin particles having carboxylic group and
sulfonyl group on their surfaces, a primary particle diameter
thereof ranging from 10 to 60 nm, and tetramethyl ammonium
hydroxide. Another includes water, polyphenol, an anionic
surfactant, ethylene diamine tetraacetic acid, resin particles
having carboxylic group and sulfonyl group on their surfaces, a
primary particle diameter thereof ranging from 10 to 60 nm, and
tetramethyl ammonium hydroxide. Both of the treating liquids have a
pH ranging from 4 to 9, and exhibit a polishing rate both of an
insulating film and a conductive film at a rate of 10 nm/min or
less.
Inventors: |
KURASHIMA; Nobuyuki;
(Yokohama-shi, JP) ; Minamihaba; Gaku;
(Yokohama-shi, JP) ; Tateyama; Yoshikuni;
(Hiratsuka-shi, JP) ; Yano; Hiroyuki;
(Yokohama-shi, JP) |
Family ID: |
39740226 |
Appl. No.: |
13/091732 |
Filed: |
April 21, 2011 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11967584 |
Dec 31, 2007 |
7951717 |
|
|
13091732 |
|
|
|
|
Current U.S.
Class: |
510/175 |
Current CPC
Class: |
H01L 21/02074
20130101 |
Class at
Publication: |
510/175 |
International
Class: |
C11D 3/60 20060101
C11D003/60 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 6, 2007 |
JP |
2007-056185 |
Jun 7, 2007 |
JP |
2007-151746 |
Claims
1. A post-CMP treating liquid comprising: water; an amphoteric
surfactant; an anionic surfactant; a complexing agent; resin
particles having carboxylic group and sulfonyl group on their
surfaces, a primary particle diameter thereof ranging from 10 to 60
nm; and tetramethyl ammonium hydroxide; the treating liquid having
a pH ranging from 4 to 9 and exhibiting a polishing rate both of an
insulating film and a conductive film at a rate of 10 nm/min or
less.
2. The post-CMP treating liquid according to claim 1, wherein the
amphoteric surfactant contains at least one selected from the group
consisting of lauryl betaine, stearyl betaine, lauryl dimethylamine
oxide, and 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium
betaine.
3. The post-CMP treating liquid according to claim 1, wherein the
amphoteric surfactant is lauryl dimethylaminoacetic acid
betaine.
4. The post-CMP treating liquid according to claim 1, wherein the
amphoteric surfactant is included at a concentration ranging from
0.0001 to 0.1 wt %.
5. The post-CMP treating liquid according to claim 4, wherein the
amphoteric surfactant is included at a concentration ranging from
0.005 to 0.05 wt %.
6. The post-CMP treating liquid according to claim 1, further
comprising a reducing agent.
7. A post-CMP treating liquid comprising: water; polyphenol; an
anionic surfactant; ethylene diamine tetraacetic acid; resin
particles having carboxylic group and sulfonyl group on their
surfaces, a primary particle diameter thereof ranging from 10 to 60
nm; and tetramethyl ammonium hydroxide; the treating liquid having
a pH ranging from 4 to 9 and exhibiting a polishing rate both of an
insulating film and a conductive film at a rate of 10 nm/min or
less.
8. The post-CMP treating liquid according to claim 7, wherein the
polyphenol is selected from the group consisting of catechin,
anthocyanidin, flavan-3,4-diol, proanthocyanidin, rutin,
isoflavone, tannin and chlorogenic acid.
9. The post-CMP treating liquid according to claim 7, wherein the
polyphenol comprises at least catechin.
10. The post-CMP treating liquid according to claim 7, wherein the
polyphenol is included at a concentration ranging from 0.0001 to
0.1 wt %.
11. The post-CMP treating liquid according to claim 10, wherein the
polyphenol is included at a concentration ranging from 0.005 to
0.05 wt %.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of and claims
the benefit of priority to U.S. application Ser. No. 11/967,584,
filed Dec. 31, 2007. The contents of U.S. application Ser. No.
11/967,584 are incorporated herein by reference in their entirety.
This application also claims the benefit of priority to Japanese
Patent Applications No. 2007-056185, filed Mar. 6, 2007; and No.
2007-151746, filed Jun. 7, 2007, the entire contents of both of
which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a treating liquid to be used after
finishing chemical mechanical polishing (CMP) and to a method of
manufacturing a semiconductor device using the treating liquid.
[0004] 2. Description of the Related Art
[0005] In recent years, a trend to further promote the fineness of
wirings has been rapidly advanced concomitant with a trend to
further promote the integration of an LSI. Additionally, it is now
considered imperative to adopt new materials for alleviating the
delay of wiring RC. Under the circumstances, it is now being
attempted to employ low resistant Cu (.rho.: 1.8 .mu..OMEGA.-cm) as
a conductive material and to employ an insulating film of low
dielectric constant (k: <2.5) as an insulating material.
[0006] The Cu wiring is mainly formed as damascene wiring by CMP.
The insulating film and wiring that have been formed by CMP are
inevitably accompanied with residues such as dusts (abrasive
particles and shavings) and unreacted slurry. As the washing liquid
to removing these residues, there have been conventionally employed
those containing a chelate complexing agent and a surfactant.
However, since intervals between wirings is required to be as small
as 0.1 .mu.m or less in a semiconductor device of the next
generation, a trace amount of fine residues that has been
considered to raise no problems up to date may cause wiring
failures such as short-circuit between wirings or the deterioration
in withstanding voltage of insulating film as the space between
wirings is further narrowed in future.
[0007] Additionally, since most of the insulating film of low
dielectric constant contains an organic component, the surface of
the film is hydrophobic and hence hardly wettable to water.
Therefore, dusts easily adsorb on the surface of insulating film
during the CMP treatment or the washing treatment. Moreover, the
dusts once adsorbed in this manner can be hardly removed, thus
giving rise to failures to form wirings which are normally
electrically isolated from each other. Further, the insulating film
having a low dielectric constant is also accompanied with a problem
that it can be easily scratched.
[0008] As the washing liquid to be employed for removing minute
particles and metal impurities which are adhered to the surface of
substrate, there has been conventionally proposed a treating liquid
containing aliphatic polycarboxylic acid and a reducing agent.
Further, there has been also proposed a treating liquid containing
resin particles for performing a post-CMP treatment. There are
increasingly demands that the surface of the insulating film in
which a conductive material is buried, in particular, the surface
of the insulating film of low dielectric constant that has been
subjected to the CMP treatment is further enhanced in cleanness and
also that the surface washed is enabled to advance to the next step
in a stabilized state. Especially, when the semiconductor substrate
is allowed to dry subsequent to the post-CMP treatment and then
left to stand in an environment of clean room, the surface of
conductive material is abnormally oxidized, thus raising the
problem of short-circuiting of wirings.
BRIEF SUMMARY OF THE INVENTION
[0009] A post-CMP treating liquid according to one aspect of the
present invention comprises water; an amphoteric surfactant; an
anionic surfactant; a complexing agent; resin particles having
carboxylic group and sulfonyl group on their surfaces, a primary
particle diameter thereof ranging from 10 to 60 nm; and tetramethyl
ammonium hydroxide; the treating liquid having a pH ranging from 4
to 9 and exhibiting a polishing rate both of an insulating film and
a conductive film at a rate of 10 nm/min or less.
[0010] A post-CMP treating liquid according to another aspect of
the present invention comprises water; polyphenol; an anionic
surfactant; ethylene diamine tetraacetic acid; resin particles
having carboxylic group and sulfonyl group on their surfaces, a
primary particle diameter thereof ranging from 10 to 60 nm; and
tetramethyl ammonium hydroxide; the treating liquid having a pH
ranging from 4 to 9 and exhibiting a polishing rate both of an
insulating film and a conductive film at a rate of 10 nm/min or
less.
[0011] A method for manufacturing a semiconductor device according
to another aspect of the present invention comprises depositing a
conductive material above an insulating film formed above a
semiconductor substrate and having a recess, thereby forming a
conductive film; polishing the conductive film to expose a surface
of the insulating film while burying the conductive material in the
recess, thereby forming a buried wiring layer; and treating a
surface of the buried wiring layer and the surface of the
insulating film using a treating liquid without substantially
polishing these surfaces, the treating liquid comprising water; an
amphoteric surfactant; an anionic surfactant; a complexing agent;
resin particles having carboxylic group and sulfonyl group on their
surfaces, a primary particle diameter thereof ranging from 10 to 60
nm; and tetramethyl ammonium hydroxide; the treating liquid having
a pH ranging from 4 to 9.
[0012] A method for manufacturing a semiconductor device according
to another aspect of the present invention comprises depositing a
conductive material above an insulating film formed above a
semiconductor substrate and having a recess, thereby forming a
conductive film; polishing the conductive film to expose a surface
of the insulating film while burying the conductive material in the
recess, thereby forming a buried wiring layer; and treating a
surface of the buried wiring layer and the surface of the
insulating film using a treating liquid without substantially
polishing these surfaces, the treating liquid comprising water;
polyphenol; an anionic surfactant; ethylene diamine tetraacetic
acid; resin particles having carboxylic group and sulfonyl group on
their surfaces, a primary particle diameter thereof ranging from 10
to 60 nm; and tetramethyl ammonium hydroxide; the treating liquid
having a pH ranging from 4 to 9.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0013] FIGS. 1A to 1C are cross-sectional views each illustrating a
step in the manufacturing method of a semiconductor device
according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Next, embodiments of the present invention will be
explained.
[0015] The post-CMP treating liquid according to embodiments of the
present invention comprises five kinds of components, the pH of the
treating liquid being within a specific range.
[0016] A first post-CMP treating liquid comprises an amphoteric
surfactant, an anionic surfactant, a complexing agent, resin
particles, and tetramethyl ammonium hydroxide.
[0017] A first component is an amphoteric surfactant. This
amphoteric surfactant dissolves a metal oxide, especially Cu oxide
to suppress the generation of abnormal oxide. It can be said that
this amphoteric surfactant removes a component which may become a
seed for generating abnormal oxide. As this amphoteric surfactant,
it can be selected from the group consisting of, for example,
lauryl betaine, stearyl betaine, lauryl dimethylamine oxide, and
2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine. These
compounds may be employed singly or in combination of two kinds
thereof. Because of saving cost, it is preferable to employ lauryl
dimethylaminoacetic acid betaine. This lauryl dimethylaminoacetic
acid betaine is advantageous in that it is high in biodegradability
and hence low in load to environments.
[0018] As long as this amphoteric surfactant is included in the
post-CMP treating liquid at a concentration of 0.0001 wt % or more,
it is possible to derive the effects thereof. As the concentration
of the amphoteric surfactant is increased, the effect of dissolving
the metal oxide can be increased. However, if the metal oxide is
excessively dissolved, a trench may be generated along the crystal
boundary of metal. Further, the amphoteric surfactant which has
been excessively incorporated may lead to the aggregation of resin
particles. In order to derive desired effects without raising any
of problems, the concentration of the amphoteric surfactant should
preferably be within the range of 0.0001 to 0.1 wt %. More
preferably, the concentration of the amphoteric surfactant should
be within the range of 0.005 to 0.05 wt %.
[0019] A second component is an anionic surfactant. As this anionic
surfactant, it is possible to employ a surfactant having carboxyl
group or a surfactant having sulfonyl group. These surfactants may
be employed singly or in combination.
[0020] As the surfactant having carboxyl group, it is possible to
employ polyacrylic acid, polyacrylate, polymethacrylic acid,
polymethacrylate, acrylic acid-methacrylic acid, acrylic
acid-methacrylate, etc. It is also possible to employ a polyvalent
carboxylic acid-based copolymer. The weight average molecular
weight of these surfactants should preferably be within the range
of 2000 to 20000. If the weight average molecular weight of these
surfactants is less than 2000, it may become difficult to derive a
sufficient washing power. On the other hand, if the weight average
molecular weight of these surfactants is more than 20000, the
aggregation of resin particles may generate, possibly resulting in
an increase of viscosity of the treating liquid.
[0021] As the surfactant having sulfonyl group, it is possible to
employ alkylbenzene sulfonate. For example, it is possible to
employ hexylbenzene sulfonic acid, octylbenzene sulfonic acid,
dodecylbenzene sulfonic acid, tetradecylbenzene sulfonic acid,
hexadecylbenzene sulfonic acid, octadecylbenzene sulfonic acid,
etc. Incidentally, because of appropriate range of molecular weight
and also because of the molecular structure wherein a straight
chain and a benzene ring are included therein and sulfonyl group is
coordinated on the surface thereof, it is especially preferable to
employ potassium dodecylbenzene sulfonate or ammonium
dodecylbenzene sulfonate.
[0022] The content of the anionic surfactant should preferably be
within the range of 0.01 to 1 wt % based on a total weight of the
treating liquid. Even if the anionic surfactant is excessively
contained, it would be impossible to obtain prominent effects.
Rather, the excessive content of anionic surfactant may give rise
to the problem that abrasive particles or dust such as shavings are
allowed to readhere to the treated surface. As long as the content
of the anionic surfactant is within the aforementioned range, it is
possible to derive desired effects without raising any
problems.
[0023] As will be described hereinafter, the post-CMP treating
liquid according to the embodiment of the present invention
comprises resin particles having, on their surfaces, two kinds of
functional groups, i.e. carboxyl group and sulfonyl group. Since
these functional groups are enabled to act on the metal of a
treated surface, it is possible to obtain various effects. Further,
since the functional groups which are similar to the aforementioned
two kinds of functional group are included also in the surfactants,
it is possible to further enhance these effects. As a result, the
removal of water marks can be promoted.
[0024] A third component is a complexing agent. This complexing
agent forms a complex with metal to promote the removal of residues
through the chemical effects thereof. As the examples of this
complexing agent, it can be selected from the group consisting of,
for example, oxalic acid, malonic acid, succinic acid, tartaric
acid, citric acid, ethylenediamine tetraacetic acid,
ethylenediamine tetra(methylene phosphonic acid),
nitrotris(methylene phosphonic acid) and salts thereof, glycine,
alanine, triethanol amine and ammonia. These compounds may be
employed singly or combination of two or more kinds.
[0025] Even if this complexing agent is contained excessively, it
would be impossible to derive any of prominent effects. Rather, the
inclusion of excessive quantity of this complexing agent may lead
to the problem that the surface of wirings is roughened. Therefore,
the content of the complexing agent should preferably be within the
range of 0.01 to 1 wt %.
[0026] A fourth component is resin particles. The resin particles
act to mechanically remove the residues from the treated
surface.
[0027] As the materials for the resin particles, it is possible to
employ, for example, poly(methyl methacrylate) (PMMA), polystyrene
(PS), polyethylene (PE), polyethylene glycol, polyvinyl acetate,
polybutadiene, polyisobutylene, polypropylene and polyoxymethylene.
The resin particles may be formed solely of a single kind of
material or formed of a combination of two or more different kinds
of these resins. Further, the resin particles can be formed through
the crosslinking of two or more kinds of resins.
[0028] The surfaces of the resin particles are constructed to have
two kinds of functional groups, i.e. carboxylic group and sulfonyl
group bonded thereto. Due to the existence of these functional
groups, chelate effect is created between the resin particles and a
metal such as Cu, etc., thereby enabling residues including metals
to be effectively removed. These carboxylic group and sulfonyl
group are capable of generating anions (--COO.sup.- and
SO.sub.3.sup.-) in the treating liquid. As compared with cations,
the anions are advantageous in the respects that they are excellent
in safety and low in manufacturing cost.
[0029] The primary particle diameter of the resin particles is
confined within the range of 10 to 60 nm. The primary particle
diameter of the resin particles can be measured from the SEM or TEM
photograph thereof. When the primary particle diameter of the resin
particles is less than 10 nm, the quantities of these two kinds of
functional groups on the surface of resin particles may become
insufficient, thus making it impossible to obtain the effects
thereof. On the other hand, when the primary particle diameter of
the resin particles exceeds 60 nm, it may become impossible to
completely remove the water marks generated on the hydrophobic
surface of insulating film. Moreover, the resin particles
themselves may remain on the treated surface, rendering them to
become a cause for generating the defectives. More preferably, the
primary particle diameter of the resin particles should be within
the range of 30 to 50 nm.
[0030] The concentration of the resin particles in the post-CMP
treating liquid should preferably be within the range of 0.01 to 1
wt %. If the resin particles are contained in the post CMP treating
liquid at a concentration exceeding 1 wt %, the resin particles
themselves leave behind after the drying process of the wiring
layer, thus generating new defectives and hence badly affecting the
semiconductor device. Additionally, the manufacturing cost of the
treating liquid itself would be increased. On the other hand, if
this concentration of the resin particles is less than 0.01 wt %,
it may become impossible to completely remove the water marks. More
preferably, the concentration of the resin particles should be
within the range of 0.05 to 0.1 wt %.
[0031] A fifth component is tetramethyl ammonium hydroxide (TMAH).
Since this TMAH is one of basic compound, it is capable of
dissolving the complex of a wiring material consisting of metal
such as Cu, etc. Moreover, by suitably adjusting the content of
TMAH, the pH of post-CMP treating liquid can be adjusted.
[0032] Incidentally, the basic compound herein is defined to
include compounds such as ethylene diamine, trimethylhydroxyethyl
ammonium (choline). Even when any of these compounds is also
incorporated in the treating liquid, it is possible to adjust the
pH of post-CMP treating liquid to the range of 4 to 9. However, in
the case of the treating liquid containing ethylene diamine for
example, there will be raised a problem that the surface of a
wiring material consisting of metal such as Cu may be etched away.
A basic compound which is capable of adjusting the pH of post-CMP
treating liquid without raising problems and, still more, capable
of dissolving a complex of metal such as Cu, etc. is TMAH.
[0033] With respect to the content of TMAH, there is not any
particular limitation, so that it can be suitably selected from
within the range which enables to secure a pH of 4 to 9 in the
post-CMP treating liquid.
[0034] When the pH of the post-CMP treating liquid is less than 4,
it may become difficult to remove the resin particles. On the other
hand, when the pH of the post-CMP treating liquid exceeds 9, it may
raise a problem that the surface of wirings is roughened. In order
to avoid these problems, the pH of post-CMP treating liquid
according to one embodiment of the present invention is kept within
the range of 4 to 9.
[0035] The first post-CMP treating liquid may further contain a
reducing agent. As the reducing agent, it is possible to employ
hydroxylamine for example. When the pH of the treating liquid is
relatively high, e.g., 8 to 9, the effect of suppressing the
corrosion of a metal such as Cu can be further enhanced by the
inclusion of the reducing agent. As the amount of the reducing
agent, there is not any particular limitation. When the amount of
the reducing agent is 0.01 wt % or more based on a total weight of
the treating liquid, the aforementioned effect can be secured.
However, when the reducing agent is excessively incorporated in the
treating liquid, problems such as the precipitation of wiring
materials may occur. Therefore, it is preferable to set the upper
limit of the reducing agent to about 1 wt % based on a total weight
of the treating liquid.
[0036] The components described above are mixed with water to
obtain a first post-CMP treating liquid. As water, there is not any
particular limitation with respect the kinds thereof and hence it
is possible to employ ion-exchange water, pure water, etc.
[0037] A second post-CMP treating liquid comprises polyphenol, an
anionic surfactant, ethylene diamine tetraacetic acid, resin
particles, and tetramethyl ammonium hydroxide. This second post-CMP
treating liquid is the same in composition with the aforementioned
first post-CMP treating liquid except that polyphenol is
incorporated as the first component and ethylene diamine
tetraacetic acid is incorporated as the third component.
[0038] The polyphenol employed as the first component is effective
in suppressing the abnormal oxidation of metal, especially Cu.
Specifically, polyphenol is enabled to adhere onto the surface of
the component that may become a seed for generating abnormal
oxides, thereby suppressing the abnormal oxidation. This polyphenol
can be selected from the group consisting of, for example,
catechin, anthocyanidin, flavan-3,4-diol, proanthocyanidin, rutin,
isoflavone, tannin and chlorogenic acid. As the anthocyanidin, it
may be of any type selected from pelargonidin type (4'-hydroxy),
cyanidin type (3',4'-dihydroxy) and delphinidin type
(3',4',5'-trihydroxy).
[0039] The aforementioned compounds can be employed singly or in
combination of two or more kinds. In view of excellent stability
and low cost, the employment of catechin is more preferable.
[0040] As long as this polyphenol is included in the post CMP
treating liquid at a concentration of 0.0001 wt % or more, it is
possible to derive the effects thereof. As the concentration of the
polyphenol is increased, the effect of suppressing the abnormal
oxidation of Cu can be increased. However, an increased
concentration of polyphenol may lead to the generation of a trench
along the crystal boundary of metal. In order to derive desired
effects without raising problems, the concentration of polyphenol
should preferably be within the range of 0.0001 to 0.1 wt %. More
preferably, the concentration of polyphenol should be within the
range of 0.005 to 0.05 wt %.
[0041] As already explained above, the ethylene diamine tetraacetic
acid employed as the third component is one kind of complexing
agent. Even if this ethylene diamine tetraacetic acid is contained
excessively, it would be impossible to derive any of prominent
effects. Rather, the inclusion of excessive quantity of this
ethylene diamine tetraacetic acid may lead to the problem that the
surface of wirings is roughened. Therefore, the concentration of
ethylene diamine tetraacetic acid should preferably be within the
range of 0.01 to 1 wt %.
[0042] This ethylene diamine tetraacetic acid is high in terms of
washing effects and hence is an excellent complexing agent.
However, when this ethylene diamine tetraacetic acid is left
contacted with metal such as Cu, there will be raised the problem
that the abnormal oxidation of metal is more likely to be
generated. It has been found out by the present inventors that when
polyphenol is incorporated in a post-CMP treating liquid containing
ethylene diamine tetraacetic acid, it is possible to suppress the
abnormal oxidation of metal. Moreover, the excellent washing
effects of ethylene diamine tetraacetic acid would not be damaged
in any substantial manner. The reason for this may be attributed to
the anti-oxidation action to be derived from this polyphenol.
[0043] Together with these polyphenol and ethylene diamine
tetraacetic acid, the same kinds of other additives as employed in
the first post-CMP treating liquid such as an anionic surfactant,
resin particles and TMAH are mixed with water to obtain the second
post-CMP treating liquid.
[0044] Incidentally, in the embodiment of the present invention,
the intention is to remove residues from the surfaces of wiring
layer and insulating film, the insulating film made of a material
such as SiO.sub.2 and the conductive film made of a material such
as Cu and Ta are not required to be polished. On the contrary, in
order to inhibit the polishing of these insulating film and
conductive film in a treatment using the treating liquid according
to embodiments of the present invention, the polishing rate of
these insulating film and conductive film by the treating liquid
according to embodiments of the present invention is confined to 10
nm/min or less. Irrespective of the treating conditions, the kinds
of these insulating film and conductive film, as long as the
polishing rate of these insulating film and conductive film is
confined to 10 nm/min or less, these films are assumed not to be
polished to any substantial degree, thereby making it possible to
exclusively obtain desired washing effects.
[0045] In order to make sure that the polishing rate is 10 nm/min
or less, it is desirable that the post-CMP treating liquid
according to embodiments of the present invention does not contain
any of oxidizing agents which may oxidize the surface of conductive
film to promote the polishing of conductive film. Further,
inorganic particles to be employed for mechanically removing oxides
that have been generated on the surface of conductive film or for
mechanically removing an insulating film should be excluded from
the post-CMP treating liquid according to embodiments.
[0046] The treating liquid as described above is fed to the surface
of object after finishing the CMP thereof and at the same time,
mechanical action is applied to the surface using a suitable member
such as a polishing pad, rolls or pencil, thereby removing residual
matters from the surface of the wiring layer and insulating layer,
thus obtaining a semiconductor device excellent in electric
properties.
[0047] Next, one example for forming a Cu damascene wiring by the
method according to one embodiment of the present invention will be
explained.
[0048] FIGS. 1A to 1C are cross-sectional views each illustrating a
step in the method according to one embodiment of the present
invention.
[0049] First of all, as shown in FIG. 1A, a barrier metal film 105
and an wiring material film 106 are successively formed, via an
inorganic insulating film 101 and laminated insulating films 103
and 104, on a semiconductor substrate 100 having elements (not
shown) formed therein.
[0050] In the inorganic film 101, plugs 102 made of W (tungsten)
are buried. The laminated insulating films are constituted by a
first insulating film 103 having a relative dielectric constant of
less than 2.5, and a second insulating film 104 having a higher
relative dielectric constant than that of the first insulating film
103. The film thickness of the first insulating film as well as of
the second insulating film may be 100 nm.
[0051] The first insulating film 103 may be formed of at least one
selected from the group consisting of a film having a siloxane
skeleton such as polysiloxane, hydrogen silsesquioxane, polymethyl
siloxane and methylsilsesquioxane; a film formed, as a major
component, of an organic resin such as polyarylene ether,
polybenzoxazole and polybenzocyclobutane; and a porous film such as
a porous silica film. The first insulating film made of these
materials is fragile.
[0052] The second insulating film 104 to be formed on the first
insulating film 103 acts as a capping insulating film and can be
formed by at least one insulating material having a relative
dielectric constant of 2.5 or more and selected from the group
consisting, for example, of SiC, SiCH, SiCN, SiOC, SiN and SiOCH.
The surface of the second insulating film 104 constituted by any of
these materials is hydrophobic. Further, even on the surface of a
hydrophilic insulating film such as SiO, SiOP, SiOF and SiON,
residual matters are enabled to adhere thereto after finishing the
process of CMP. Even to such an insulating film, the treating
liquid according to one embodiment of the present invention can be
suitably applied.
[0053] The barrier metal film 105 and the wiring material film 106
are deposited on the aforementioned laminated insulating films
having a wiring trench formed therein. The barrier metal film 105
may be deposited to a thickness of 10 nm using Ta. The wiring
material film 106 may be deposited to a thickness of 400 nm using
Cu.
[0054] Incidentally, in the example shown in FIG. 1A, although the
insulating film on which the barrier metal film 105 and the wiring
material film 106 are formed is constituted by a laminate structure
comprising the first insulating film 103 and the second insulating
film 104, this insulating film may be constituted by a single layer
of insulating film. The insulating film in this case may be formed
using black diamond (Applied Materials Co., Ltd.), etc. The surface
of the insulating film formed of such a material is also
hydrophobic.
[0055] Then, redundant portions of the barrier metal film 105 and
the wiring material film 106 are removed by CMP, thereby exposing
the surface of the second insulating film 104 as shown in FIG. 1B.
The CMP of conductive film such as the barrier metal film 105 and
the wiring material film 106 can be performed by the oxidation of
the surfaces of these films to form fragile oxide and then by the
mechanical removal of this fragile oxide. Incidentally, in this
CMP, the removal of the wiring material film 106 (1st polishing)
and the removal of the barrier metal film 105 (2nd polishing) were
performed in two steps, the conditions thereof being as shown
below.
[0056] (1st polishing)
[0057] Slurry: CMS7401/7452 (JSR Co., Ltd.)
[0058] Flow rate: 300 cc/min.
[0059] Polishing pad: IC1000 (Nitta Haas Co., Ltd.)
[0060] Load: 300 gf/cm.sup.2.
[0061] The rotational speeds of the carrier and the table were both
set to 100 rpm and the polishing was performed for one minute.
[0062] (2nd polishing)
[0063] Slurry: CMS8401/8452 (JSR Co., Ltd.)
[0064] Flow rate: 200 cc/min.
[0065] Polishing pad: IC1000 (Nitta Haas Co., Ltd.)
[0066] Load: 300 gf/cm.sup.2.
[0067] The rotational speeds of the carrier and the table were both
set to 100 rpm and the polishing was performed for 30 seconds.
[0068] Residues such as abrasive grains 107, polished debris or
products 108 and water marks 109 were found adhered to the surfaces
of the second insulating film 104, the barrier metal film 105 and
the wiring material film 106 immediately after the 2nd polishing as
shown in FIG. 1B. The residues such as abrasive grains 107,
polished debris 108 and water marks 109 adhered in this manner
would become a cause for generating defectives.
[0069] By subjecting the resultant surface to washing (post-CMP
treatment) with a treating liquid, these residues thus adhered can
be removed as shown in FIG. 1C. In the case of the conventional
washing liquid however, when a semiconductor substrate is allowed
to dry after finishing the post-CMP treatment and left to stand in
an environment of clean room for 24 hours, the surface of the
wiring material is abnormally oxidized, thus raising a problem that
abnormal oxide 110 is created thereon.
[0070] It is possible, through the employment of the post-CMP
treating liquid according to embodiments of the present invention,
to remove various kinds of adhered matters and to suppress the
generation of abnormal oxide 110.
[0071] The treating liquid according to the embodiment of the
present invention was prepared according to the following
procedures.
Example I-1
[0072] The components were respectively blended with water
according to the following recipe to prepare the treating liquid of
Example I-1. The treating liquid thus obtained exhibited a pH of
4.
TABLE-US-00001 Amphoteric surfactant: Lauryl dimethylaminoacetic
0.005 wt % acid betaine -- Anionic surfactant: Ammonium
polyacrylate -- 0.1 wt % Ammonium dodecylbenzene sulfonate -- 0.1
wt % Complexing agent: Glycine -- 0.05 wt % Resin particles:
PMMA-polystyrene crosslinked 0.1 wt % particles (primary particle
diameter: 50 nm) having carboxyl group and sulfonyl group on their
surfaces -- TMAH -- 0.03 wt %
Example I-2
[0073] The treating liquid of Example I-2 was prepared in the same
manner as described in Example I-1 except that the amphoteric
surfactant was changed to lauryl dimethylamine oxide, the content
of which being 0.008 wt %.
Example I-3
[0074] The treating liquid of Example I-3 was prepared in the same
manner as described in Example I-1 except that potassium
polyacrylate was substituted for ammonium polyacrylate employed as
an anionic surfactant.
Example I-4
[0075] The treating liquid of Example I-4 was prepared in the same
manner as described in Example I-1 except that only 0.1 wt % of
ammonium polyacrylate was employed as an anionic surfactant.
Example I-5
[0076] The treating liquid of Example I-5 was prepared in the same
manner as described in Example I-1 except that only 0.1 wt % of
ammonium dodecylbenzene sulfonate was employed as an anionic
surfactant.
Example I-6
[0077] The treating liquid of Example I-6 was prepared in the same
manner as described in Example I-1 except that the complexing agent
was changed to alanine, the content of which being 0.08 wt %.
Examples I-7 to I-12
[0078] The treating liquids of Examples I-7, I-8, I-9, I-10, I-11
and I-12 were prepared in the same manner as described in Example
I-1 except that the content of amphoteric surfactant was changed to
0.0005, 0.001, 0.01, 0.05, 0.1 and 0.5 wt %, respectively.
Example I-13
[0079] The treating liquid of Example I-13 was prepared in the same
manner as described in Example I-1 except that the primary particle
diameter of the resin particles was changed to 10 nm.
Example I-14
[0080] The treating liquid of Example I-14 was prepared in the same
manner as described in Example I-1 except that the primary particle
diameter of the resin particles was changed to 60 nm.
Example I-15
[0081] The treating liquid of Example I-15 was prepared in the same
manner as described in Example I-1 except that the material of the
resin particles was changed to polystyrene.
Examples I-16 to I-20
[0082] The treating liquids of Examples I-16, I-17, I-18, I-19 and
I-20 were prepared in the same manner as described in Example I-1
except that the pH thereof was changed to 5, 6, 7, 8 and 9,
respectively.
Example I-21
[0083] The treating liquid of Example I-21 was prepared in the same
manner as described in Example I-20 except that 0.1 wt % of
hydroxylamine was additionally incorporated therein as a reducing
agent.
[0084] Using each of these treating liquids thus obtained in
Examples I-1 to I-21, the surface having the features as shown in
FIG. 1B was washed. The washing was performed by contacting a
polishing pad (Nitta Haas Co., Ltd.) with the surface to be treated
while feeding a treating liquid to the polishing pad under the
following conditions, in which the surface to be treated
(hereinafter referred to as a treated surface) was rubbed by the
polishing pad for 30 seconds.
[0085] Flow rate of washing liquid: 300 cc/min.
[0086] Load: 300 gf/cm.sup.2.
[0087] Rotational speeds of the carrier and the table: both 100
rpm.
[0088] Subsequently, the treating liquid was replaced by pure water
and washing was continued under the same conditions as described
above, thus subjecting the treated surface to rubbing for 30
seconds. Finally, the treated surface was subjected to spin-rinse
drying.
[0089] The surface having the features as shown in FIG. 1B was
washed in the same manner as described above except that the
treating liquids as described below were employed, these washing
experiments being referred to as Comparative Examples I-1 to I-13.
The treating liquids employed in these comparative examples were
prepared in the same manner as described in Example I-1 except the
changes in recipe as pointed out below.
Comparative Example I-1
[0090] The amphoteric surfactant was not incorporated.
Comparative Example I-2
[0091] The amphoteric surfactant was changed to ethylene diamine
tetraacetic acid, the content of which being 0.05 wt %.
Comparative Example I-3
[0092] The anionic surfactant was not incorporated.
Comparative Example I-4
[0093] The anionic surfactant was changed to lauryl trimethyl
ammonium chloride acting as a cationic surfactant.
Comparative Example I-5
[0094] The complexing agent was not incorporated.
Comparative Example I-6
[0095] The resin particles were not incorporated.
Comparative Example I-7
[0096] The primary particle diameter of the resin particles was
changed to 8 nm.
Comparative Example I-8
[0097] The primary particle diameter of the resin particles was
changed to 80 nm.
Comparative Example I-9
[0098] The resin particles having only carboxyl group on their
surfaces was employed.
Comparative Example I-10
[0099] The resin particles having only sulfonyl group on their
surfaces was employed.
Comparative Example I-11
[0100] The TMAH was changed to ethylene diamine.
Comparative Example I-12
[0101] The pH was changed to 3.
Comparative Example I-13
[0102] The pH was changed to 10.
[0103] Incidentally, the ethylene diamine tetraacetic acid employed
in Comparative Example I-2 is weakly cationic and is known to be
effective in dissolving metal oxide. In Comparative Example I-11,
the pH was 4. Further, in Comparative Examples I-12 and I-13, the
pH thereof was controlled to a predetermined value through the
adjustment of the content of TMAH.
[0104] After the washing treatment, the measurement of light field
defectives in a region (174.25 cm.sup.2/wafer) on a pattern wafer
was performed. As the kinds of defectives assessed herein, they
included dust and scratches observed generally after the CMP
thereof in addition to the water mark (WM) on the insulating film
and the residues of resin particles remaining on the entire surface
thus treated. Incidentally, the dust and scratches were
investigated throughout the entire surface thus treated.
Additionally, the assessment of defectives on the surface of
pattern wafer was performed 24 hours later to investigate the
presence or absence of abnormal oxide on the surface of Cu
film.
[0105] As for the water marks, residues of particles, dust and
scratches, they were assessed based on the number thereof that had
been confirmed on the Cu film and the insulating film and were
judged according to the following criterion.
[0106] Removal of water marks: zero--.largecircle.; one to less
than ten--.DELTA.; ten or more--X.
[0107] Residues of particles: zero--.largecircle.; one to less than
ten--.DELTA.; ten or more--X.
[0108] Dust particles: less than five--.largecircle.; five to less
than 20--.DELTA.; 20 or more--X.
[0109] Scratches: less than five--.largecircle.; five to less than
20--.DELTA.; 20 or more--X.
[0110] The presence or absence of abnormal oxide was assessed based
on the number thereof that had been confirmed on the Cu film and
was judged according to the following criterion.
[0111] Zero--.largecircle.; one to less than ten--.DELTA.; ten or
more--X.
[0112] Even if the number of mark "X" is limited to one in these
five kinds of assessment of the treating liquid, the treating
liquid was considered unacceptable. Further, if the number of mark
".DELTA." is limited to not more than two, the treating liquid was
considered acceptable.
[0113] The results thus obtained are summarized in the following
Tables 1 and 2.
TABLE-US-00002 TABLE 1 Abnormal Residual oxidation Exs. WM
particles Dusts Scratches of Cu I-1 .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. I-2 .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. I-3
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. I-4 .largecircle. .largecircle. .largecircle.
.largecircle. .DELTA. I-5 .largecircle. .largecircle. .DELTA.
.largecircle. .largecircle. I-6 .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. I-7 .largecircle.
.largecircle. .largecircle. .largecircle. .DELTA. I-8 .largecircle.
.largecircle. .largecircle. .largecircle. .DELTA. I-9 .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. I-10
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. I-11 .largecircle. .largecircle. .largecircle.
.largecircle. .DELTA. I-12 .largecircle. .DELTA. .largecircle.
.largecircle. .DELTA. I-13 .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. I-14 .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. I-15
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. I-16 .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. I-17 .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. I-18 .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. I-19
.largecircle. .DELTA. .largecircle. .largecircle. .largecircle.
I-20 .largecircle. .largecircle. .largecircle. .largecircle.
.DELTA. I-21 .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle.
TABLE-US-00003 TABLE 2 Abnormal Comp. Residual oxidation Exs. WM
particles Dusts Scratches of Cu I-1 .largecircle. .largecircle.
.largecircle. .largecircle. X I-2 .largecircle. X .DELTA. .DELTA.
.DELTA. I-3 X .DELTA. X .largecircle. X I-4 X X X .largecircle.
.DELTA. I-5 X X .largecircle. .largecircle. X I-6 X .largecircle. X
.largecircle. X I-7 .DELTA. X .DELTA. .largecircle. .largecircle.
I-8 X .DELTA. .largecircle. .largecircle. .largecircle. I-9 X
.largecircle. .DELTA. .largecircle. .largecircle. I-10 X
.largecircle. .DELTA. .largecircle. .largecircle. I-11 .DELTA.
.largecircle. X .largecircle. .DELTA. I-12 .largecircle. X
.largecircle. .largecircle. .largecircle. I-13 .largecircle.
.largecircle. .largecircle. .largecircle. X
[0114] As shown in above Table 1, when the treated surface was
treated using treating liquids each containing prescribed
components and exhibiting a pH ranging from 4 to 9 (Examples I-1 to
I-21), it was possible to minimize the residues or defectives on
the resultant surface thus treated and to suppress the generation
of abnormal oxidation of Cu.
[0115] Incidentally, in every examples, the polishing rate of the
wiring material film 106 was about 1 nm/min and the polishing rate
of the second insulating film 104 was about 1 nm/min.
[0116] In view of these results, it was assumed that when the
treating liquid was constructed as represented by these Examples,
it was possible to effectively remove residues through mechanical
action without imposing excessive loads on a hydrophobic fragile
insulating film having low dielectric constant. Especially, it was
possible to suppress the generation of abnormal oxidation on the
surface of Cu film that may bring about the deterioration of
electric properties and to prevent scratching.
[0117] Whereas, in the cases of the treating liquids of Comparative
Examples, they were all incapable of sufficiently suppressing the
generation of defectives. Specifically, in the case where an
amphoteric surfactant was not incorporated in the treating liquid
(Comparative Example I-1), it was impossible to suppress the
generation of abnormal oxidation of Cu. In the case where ethylene
diamine tetraacetic acid was incorporated in the treating liquid
(Comparative Example I-2), a great amount of residual particles
were left behind and it was impossible to reduce dust, scratches
and abnormal oxidation of Cu in spite of the fact that ethylene
diamine tetraacetic acid is inherently capable of dissolving metal
oxide. It was assumed that due to this compound, aggregation of
resin particles was caused to occur, resulting in the generation of
defectives.
[0118] In the case where an anionic surfactant was not incorporated
in the treating liquid (Comparative Example I-3), it was impossible
to suppress not only the abnormal oxidation but also the generation
of water marks and dust. In the case where a cationic surfactant
was employed in place of the anionic surfactant (Comparative
Example I-4), abrasive particles and dust such as shavings were
re-adhered to the treated surface and the generation of water marks
originated from these particles and dust acting as a seed was
promoted. In the case where a complexing agent was not incorporated
in the treating liquid (Comparative Example I-5), it was impossible
not only to suppress the generation of defectives but also to
sufficiently remove the residual particles.
[0119] In the case where resin particles were not incorporated in
the treating liquid (Comparative Example I-6), it was impossible
not only to suppress the abnormal oxidation but also to minimize
the generation of water marks and dust. In the case where the
primary particle diameter of resin particles was too small
(Comparative Example I-7), it was impossible to sufficiently remove
the residual particles. On the other hand, in the case where the
primary particle diameter of resin particles was too large
(Comparative Example I-8), it was impossible to sufficiently remove
the water marks.
[0120] In the case where the functional group existing on the
surface of resin particle was limited to one kind (Comparative
Examples I-9 and I-10), it was impossible to bring about a
chelating action with the residual matters containing metal, thus
making it impossible to enhance the capacity of the treating liquid
to remove the residual dust and water marks.
[0121] In the case where another kind of basic compound was
employed in place of TMAH (Comparative Examples I-11), it was
impossible to sufficiently remove the residual dust. Even if all of
predetermined components were incorporated in the treating liquid
(Comparative Examples I-12 and I-13), it was impossible to
sufficiently remove the residual particles and to suppress the
generation of abnormal oxidation provided that the pH thereof was
less than 4 or more than 9.
[0122] It was confirmed from these results that as long as the
treating liquid was formulated to include an amphoteric surfactant,
an anionic surfactant, a complexing agent, TMAH and resin particles
having a primary particle diameter within a specific range and
specific functional groups on their surfaces, wherein the treating
liquid was also formulated to exhibit a pH ranging from 4 to 9, it
was possible to derive excellent effects from the treating
liquid.
Example II-1
[0123] The components were respectively blended with water
according to the following recipe to prepare the treating liquid of
Example II-1. The treating liquid thus obtained exhibited a pH of
4.
TABLE-US-00004 Polyphenol: Catechin -- 0.005 wt % Anionic
surfactant: Ammonium polyacrylate -- 0.1 wt % Ammonium
dodecylbenzene sulfonate -- 0.1 wt % Ethylene diamine tetraacetic
acid -- 0.05 wt % Resin particles: PMMA-polystyrene crosslinked 0.1
wt % particles (primary particle diameter: 50 nm) having carboxyl
group and sulfonyl group on their surfaces -- TMAH -- 0.03 wt %
Example II-2
[0124] The treating liquid of Example II-2 was prepared in the same
manner as described in Example II-1 except that the catechin
employed as polyphenol was changed to rutin, the content of which
being 0.005 wt %.
Example II-3
[0125] The treating liquid of Example II-3 was prepared in the same
manner as described in Example II-1 except that potassium
polyacrylate was substituted for ammonium polyacrylate employed as
an anionic surfactant.
Example II-4
[0126] The treating liquid of Example II-4 was prepared in the same
manner as described in Example II-1 except that only 0.1 wt % of
ammonium polyacrylate was employed as an anionic surfactant.
Example II-5
[0127] The treating liquid of Example II-5 was prepared in the same
manner as described in Example II-1 except that only 0.1 wt % of
ammonium dodecylbenzene sulfonate was employed as an anionic
surfactant.
Example II-6 to II-11
[0128] The treating liquids of Examples II-6, II-7, II-8, II-9,
II-10 and II-11 were prepared in the same manner as described in
Example II-1 except that the concentration of polyphenol was
changed to 0.0001, 0.0005, 0.001, 0.01, 0.05 and 0.1 wt %,
respectively.
Example II-12
[0129] The treating liquid of Example II-12 was prepared in the
same manner as described in Example II-1 except that the primary
particle diameter of the resin particles was changed to 10 nm.
Example II-13
[0130] The treating liquid of Example II-13 was prepared in the
same manner as described in Example II-1 except that the primary
particle diameter of the resin particles was changed to 60 nm.
Example II-14
[0131] The treating liquid of Example II-14 was prepared in the
same manner as described in Example II-1 except that the material
of the resin particles was changed to polystyrene.
Examples II-15 to II-19
[0132] The treating liquids of Examples II-15, II-16, II-17, II-18
and II-19 were prepared in the same manner as described in Example
II-1 except that the pH thereof was changed to 5, 6, 7, 8 and 9,
respectively.
[0133] Using each of these treating liquids thus obtained in
Examples II-1 to II-19, the surface having the features as shown in
FIG. 1B was washed. The washing was performed by contacting a
polishing pad (Nitta Haas Co., Ltd.) with the treated surface while
feeding a treating liquid to the surface of polishing pad under the
following conditions, in which the treated surface was rubbed by
the polishing pad for 30 seconds.
[0134] Flow rate of washing liquid: 300 cc/min.
[0135] Load: 300 gf/cm.sup.2.
[0136] Rotational speeds of the carrier and the table: both 100
rpm.
[0137] Subsequently, the treating liquid was replaced by pure water
and washing was continued under the same conditions as described
above, thus subjecting the treated surface to rubbing for 30
seconds. Finally, the treated surface was subjected to spin-rinse
drying.
[0138] The surface having the features as shown in FIG. 1B was
washed in the same manner as described above except that the
treating liquids as described below were employed, these washing
experiments being referred to as Comparative Examples II-1 to
II-12. The treating liquids employed in these comparative examples
were prepared in the same manner as described in Example II-1
except the changes in recipe as pointed out below.
Comparative Example II-1
[0139] Polyphenol was not incorporated.
Comparative Example II-2
[0140] Polyphenol was changed to benzotriazole (BTA), the content
of which being 0.05 wt %.
Comparative Example II-3
[0141] The anionic surfactant was not incorporated.
Comparative Example II-4
[0142] Ethylene diamine tetraacetic acid was not incorporated.
Comparative Example II-5
[0143] The resin particles were not incorporated.
Comparative Example II-6
[0144] The primary particle diameter of the resin particles was
changed to 8 nm.
Comparative Example II-7
[0145] The primary particle diameter of the resin particles was
changed to 80 nm.
Comparative Example II-8
[0146] The resin particles having only carboxyl group on their
surfaces was employed.
Comparative Example II-9
[0147] The resin particles having only sulfonyl group on their
surfaces was employed.
Comparative Example II-10
[0148] The TMAH was changed to ethylene diamine.
Comparative Example II-11
[0149] The pH was changed to 3.
Comparative Example II-12
[0150] The pH was changed to 10.
[0151] Incidentally, the BTA employed in Comparative Example II-2
is known to be effective as a corrosion inhibitor for metal. In
Comparative Example II-10, the pH was 4. Further, in Comparative
Examples II-11 and II-12, the pH thereof was controlled to a
predetermined value through the adjustment of the content of
TMAH.
[0152] After the washing treatment, the measurement of light field
defectives in a region (174.25 cm.sup.2/wafer) on a pattern wafer
was performed. As for the kinds of defectives assessed herein, they
included dust and scratches observed generally after the CMP
thereof in addition to the water marks on the insulating film and
the residues of resin particles remaining on the entire surface
thus treated. Incidentally, the dust and scratches were
investigated throughout the entire surface thus treated.
Additionally, the assessment of defectives on the surface of
pattern wafer was performed 24 hours later to investigate the
presence or absence of abnormal oxide on the surface of Cu
film.
[0153] As for the water marks, residues of particles, dust and
scratches, they were assessed based on the number thereof that had
been confirmed on the Cu film and the insulating film and were
judged according to the aforementioned criterion.
[0154] The results thus obtained are summarized in the following
Tables 3 and 4.
TABLE-US-00005 TABLE 3 Abnormal Residual oxidation Exs. WM
particles Dusts Scratches of Cu II-1 .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. II-2 .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. II-3
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. II-4 .largecircle. .largecircle. .DELTA.
.largecircle. .DELTA. II-5 .largecircle. .largecircle. .DELTA.
.largecircle. .DELTA. II-6 .largecircle. .largecircle.
.largecircle. .largecircle. .DELTA. II-7 .largecircle.
.largecircle. .largecircle. .largecircle. .DELTA. II-8
.largecircle. .largecircle. .largecircle. .largecircle. .DELTA.
II-9 .largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. II-10 .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. II-11 .largecircle. .DELTA.
.largecircle. .largecircle. .DELTA. II-12 .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. II-13
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. II-14 .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. II-15 .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. II-16 .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. II-17
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. II-18 .largecircle. .DELTA. .largecircle.
.largecircle. .largecircle. II-19 .largecircle. .largecircle.
.largecircle. .largecircle. .DELTA.
TABLE-US-00006 TABLE 4 Abnormal Comp. Residual oxidation Exs. WM
particles Dusts Scratches of Cu II-1 .largecircle. .largecircle.
.largecircle. .largecircle. X II-2 .largecircle. X .DELTA. .DELTA.
.largecircle. II-3 X .DELTA. X .largecircle. X II-4 X X
.largecircle. .largecircle. X II-5 X .largecircle. X .largecircle.
X II-6 .DELTA. X .DELTA. .largecircle. .largecircle. II-7 X .DELTA.
.largecircle. .largecircle. .largecircle. II-8 X .largecircle. X
.largecircle. .largecircle. II-9 X .largecircle. X .largecircle.
.largecircle. II-10 .DELTA. .largecircle. X .largecircle. .DELTA.
II-11 .largecircle. X .largecircle. .largecircle. .largecircle.
II-12 .largecircle. .largecircle. .largecircle. .largecircle. X
[0155] As shown in above Table 3, when the treated surface was
treated using treating liquids each containing prescribed
components and exhibiting a pH ranging from 4 to 9 (Examples II-1
to II-19), it was possible to minimize the residues or defectives
on the resultant surface thus treated and to suppress the
generation of abnormal oxidation of Cu.
[0156] Incidentally, in every examples, the polishing rate of the
wiring material film 106 was about 1 nm/min and the polishing rate
of the second insulating film 104 was about 1 nm/min.
[0157] In view of these results, it was assumed that when the
treating liquid was constructed as represented by these Examples,
it was possible to effectively remove residues through mechanical
action without imposing excessive loads on a hydrophobic fragile
insulating film having low dielectric constant. Especially, it was
possible to suppress the generation of abnormal oxidation on the
surface of Cu film that may bring about the deterioration of
electric properties and to prevent scratching.
[0158] Whereas, in the cases of the treating liquids of Comparative
Examples, they were all incapable of sufficiently suppressing the
generation of defectives. Specifically, in the case where
polyphenol was not incorporated in the treating liquid (Comparative
Example II-1), it was impossible to suppress the generation of
abnormal oxidation of Cu. In the case where BTA was incorporated in
the treating liquid (Comparative Example II-2), a great amount of
residual particles were left behind and it was impossible to
sufficiently reduce dust and scratches in spite of the fact that
BTA is effective in preventing the corrosion of metal. It was
assumed that due to this compound, aggregation of resin particles
was caused to occur, resulting in the generation of defectives.
[0159] In the case where an anionic surfactant was not incorporated
in the treating liquid (Comparative Example II-3), it was
impossible to suppress not only the abnormal oxidation but also the
generation of water marks and dust. In the case where ethylene
diamine tetraacetic acid was not included in the treating liquid
(Comparative Example II-4), it was impossible not only to suppress
the generation of defectives but also to sufficiently remove the
residual particles.
[0160] In the case where resin particles were not incorporated in
the treating liquid (Comparative Example II-5), it was impossible
not only to suppress the abnormal oxidation but also to minimize
the generation of water marks and dust. In the case where the
primary particle diameter of resin particles was too small
(Comparative Example II-6), it was impossible to sufficiently
remove the residual particles. On the other hand, in the case where
the primary particle diameter of resin particles was too large
(Comparative Example II-7), it was impossible to sufficiently
remove the water marks.
[0161] In the case where the functional group existing on the
surface of resin particle was limited to one kind (Comparative
Examples II-8 and II-9), it was impossible to bring about a
chelating action with the residual matters containing metal, thus
making it impossible to enhance the capacity of the treating liquid
to remove the residual dust and water marks.
[0162] In the case where another kind of basic compound was
employed in place of TMAH (Comparative Examples II-10), it was
impossible to sufficiently remove the residual dust. Even if all of
predetermined components were incorporated in the treating liquid
(Comparative Examples II-11 and II-12), it was impossible to
sufficiently remove the residual particles and to suppress the
generation of abnormal oxidation provided that the pH thereof was
less than 4 or more than 9.
[0163] It was confirmed from these results that as long as the
treating liquid was formulated to include polyphenol, an anionic
surfactant, ethylene diamine tetraacetic acid, TMAH and resin
particles having a primary particle diameter within a specific
range and specific functional groups on their surfaces, wherein the
treating liquid was also formulated to exhibit a pH ranging from 4
to 9, it was possible to derive excellent effects from the treating
liquid.
[0164] As described above, the treating liquids according to
embodiments of the present invention are prominently effective in
suppressing the generation of abnormal oxidation of metal and also
effective in removing water marks and dust and in suppressing
scratching.
[0165] Although the embodiment of the present invention are
explained with reference to examples of post-treatment after
finishing the Cu-CMP, it should be construed that the present
invention is not confined to these examples. The treating liquid
comprising five kinds of components employed herein can be also
applied likewise to the formation of buried electrodes, wirings and
plugs where Al, W and polysilicon are employed, thus obtaining
almost the same effects as described above. Further, the treating
liquid of the embodiment of the present invention can be also
applied to the post-treatment after CMP of SiO.sub.2 employed as an
insulating film to be formed on the wiring layer or in an element
isolation region, making it possible to effectively wash it to
obtain a clean surface thereof.
[0166] According to one aspect of the present invention, it is
possible to provide a post-CMP treating liquid which is capable of
effectively removing the residues adhered to the surfaces of the
wiring material layer and insulating layer and which is also
excellent in suppressing the generation of abnormal oxidation of
conductive material. According to another aspect of the present
invention, it is possible to provide a method for manufacturing a
semiconductor device using this post CMP treating liquid.
[0167] According to the present invention, it is possible to
manufacture a semiconductor device having high performance and high
speed, which is provided with a wiring having a design rule of 0.05
.mu.m or less which is required in a semiconductor device of the
next generation, thus presenting enormous industrial values.
[0168] Additional advantages and modifications will readily occur
to those skilled in the art. Therefore, the invention in its
broader aspects is not limited to the specific details and
representative embodiments shown and described herein. Accordingly,
various modifications may be made without departing from the spirit
or scope of the general inventive concept as defined by the
appended claims and their equivalents.
* * * * *