U.S. patent application number 15/373724 was filed with the patent office on 2017-06-15 for substrate processing apparatus, substrate processing method and recording medium.
The applicant listed for this patent is Tokyo Electron Limited. Invention is credited to Keiichi Fujita, Masato Hamada, Tomohisa Hoshino.
Application Number | 20170170021 15/373724 |
Document ID | / |
Family ID | 59020875 |
Filed Date | 2017-06-15 |
United States Patent
Application |
20170170021 |
Kind Code |
A1 |
Hoshino; Tomohisa ; et
al. |
June 15, 2017 |
SUBSTRATE PROCESSING APPARATUS, SUBSTRATE PROCESSING METHOD AND
RECORDING MEDIUM
Abstract
In a substrate processing apparatus 1, a plating unit 4 includes
a catalyst solution supply unit 43a and a plating liquid supply
unit 45. By supplying, from the catalyst solution supply unit 43a
onto a substrate W1 having an impurity-doped polysilicon film 90
containing a high concentration of impurities on a surface thereof,
an alkaline catalyst solution L1 containing a complex of a
palladium ion and a monocyclic 5- or 6-membered aromatic or
aliphatic heterocyclic compound having one or two nitrogen atoms as
a heteroatom, a catalyst layer 91 is formed on a surface of the
impurity-doped polysilicon film 90 of the substrate W1. After the
catalyst solution L1 is supplied, an electroless plating layer 92
is formed on the catalyst layer 91 formed on a substrate W2 by
supplying a plating liquid M1 from the plating liquid supply unit
45 onto the substrate W2.
Inventors: |
Hoshino; Tomohisa; (Nirasaki
City, JP) ; Fujita; Keiichi; (Nirasaki City, JP)
; Hamada; Masato; (Nirasaki City, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Tokyo Electron Limited |
Tokyo |
|
JP |
|
|
Family ID: |
59020875 |
Appl. No.: |
15/373724 |
Filed: |
December 9, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C25D 7/123 20130101;
C23C 18/1675 20130101; C23C 18/1619 20130101; C23C 18/1633
20130101; H01L 21/288 20130101; C23C 18/1879 20130101; H01L
21/76898 20130101; C23C 18/1653 20130101; H01L 21/76874 20130101;
C23C 18/1696 20130101; C23C 18/40 20130101; H01L 21/76873 20130101;
H01L 21/32051 20130101 |
International
Class: |
H01L 21/288 20060101
H01L021/288; H01L 21/768 20060101 H01L021/768; H01L 21/3205
20060101 H01L021/3205; C23C 18/16 20060101 C23C018/16 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 11, 2015 |
JP |
2015-242609 |
Claims
1. A plasma processing apparatus configured to perform a plating
processing on a substrate having, on a surface thereof, an
impurity-doped polysilicon film containing a high concentration of
impurities, the substrate processing apparatus comprising: a
catalyst solution supply unit configured to supply, onto the
substrate, an alkaline catalyst solution containing a complex of a
palladium ion and a monocyclic 5- or 6-membered heterocyclic
compound having one or two nitrogen atoms as a heteroatom; a
plating liquid supply unit configured to supply a plating liquid
onto the substrate; and a controller configured to control
operations of the catalyst solution supply unit and the plating
liquid supply unit, wherein the controller controls the catalyst
solution supply unit and the plating liquid supply unit such that
the catalyst solution is supplied onto the substrate by the
catalyst solution supply unit and, after the catalyst solution is
supplied, the plating liquid is supplied onto the substrate by the
plating liquid supply unit.
2. The substrate processing apparatus of claim 1, wherein the
substrate further includes a base member and an insulating film
formed between the base member and the impurity-doped polysilicon
film.
3. The substrate processing apparatus of claim 1, wherein the
heterocyclic compound is selected from a group consisting of
pyrroline, pyrrole, imidazoline, imidazole, pyrazoline, pyrazole,
pyridine, pyridazine, pyrimidine, pyrazine, pyrrolidine,
imidazolidine, pyrazolidine, piperidine and piperazine.
4. The substrate processing apparatus of claim 1, wherein the
heterocyclic compound has a substituent selected from a group
consisting of a hydroxyl group, a carboxyl group and a sulfate
group.
5. A substrate processing method of performing a plating processing
on a substrate having, on a surface thereof, an impurity-doped
polysilicon film containing a high concentration of impurities, the
substrate processing method comprising: forming a catalyst layer by
supplying, onto the substrate, an alkaline catalyst solution
containing a complex of a palladium ion and a monocyclic 5- or
6-membered heterocyclic compound having one or two nitrogen atoms
as a heteroatom; and forming a plating layer through electroless
plating by supplying a plating liquid onto the substrate after the
forming of the catalyst layer.
6. The substrate processing method of claim 5, wherein the
substrate further includes a base member and an insulating film
formed between the base member and the impurity-doped polysilicon
film.
7. The substrate processing method of claim 5, wherein the
heterocyclic compound is selected from a group consisting of
pyrroline, pyrrole, imidazoline, imidazole, pyrazoline, pyrazole,
pyridine, pyridazine, pyrimidine, pyrazine, pyrrolidine,
imidazolidine, pyrazolidine, piperidine and piperazine.
8. The substrate processing method of claim 5, wherein the
heterocyclic compound has a substituent selected from a group
consisting of a hydroxyl group, a carboxyl group and a sulfate
group.
9. A computer-readable recording medium having stored thereon
computer-executable instructions that, in response to execution,
cause a substrate processing apparatus to perform a substrate
processing method as claimed in claim 5.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Japanese Patent
Application No. 2015-242609 filed on Dec. 11, 2015, the entire
disclosures of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The embodiments described herein pertain generally to a
substrate processing apparatus and a substrate processing method.
Further, the exemplary embodiments also relate to a recording
medium having stored there on a program for implementing the
substrate processing method.
BACKGROUND
[0003] Recently, a semiconductor device such as a LSI is required
to be more highly densified to meet such requirements as reduction
of a footprint (mounting space) or improvement of a processing
rate. As an example of technology for achieving the high
densification, there is known a multilayer wiring technology of
manufacturing a multilayer substrate such as a three-dimensional
LSI by stacking a multiple number of wiring substrates.
[0004] Generally, in the multilayer wiring technology, a
through-via-hole (TSV (Through Silicon Via)) in which a conductive
material such as copper is buried is formed to penetrate each
wiring substrate to achieve electrical conduction between the
wiring substrates. As an example of a technology for forming the
TSV in which the conductive material is buried, there is known an
electroless plating method.
[0005] In case of forming a plating layer by electroless plating,
it is needed to improve adhesivity between an underlying layer and
the plating layer. As an example of a technique for improving the
adhesivity between the underlying layer and the plating layer,
there is known a method in which metal catalyst particles such as
palladium serving as a catalyst for forming the plating layer are
coupled to the underlying layer, and the plating layer is formed
through the electroless plating by using the catalyst as a base of
a plating reaction. If, however, it is attempted to couple the
metal catalyst particles such as palladium to the underlying layer
directly, the metal catalyst particles may be aggregated depending
on a material of the underlying layer, so that the metal catalyst
particles may not be coupled to the underlying layer with a
sufficiently high uniformity enough to form the plating layer. As a
result, the metal catalyst particles may not function as the
catalyst sufficiently so that the plating layer may not be formed
efficiently, or the aggregated metal catalyst particles may become
a hindrance to a manufacture of a multilayer substrate.
[0006] As an example of a technique for suppressing such
aggregation of the metal catalyst particles, there is known a
method in which a self-assembled monolayer (SAM) is formed on the
underlying layer by an underlying layer processing with a coupling
agent such as a silane coupling agent, and the metal catalyst
particles such as palladium are coupled to the underlying layer
with the self-assembled monolayer therebetween (see, for example,
Patent Document 1).
[0007] Patent Document 1: Japanese Patent Laid-open Publication No.
2002-302773
[0008] In case that the underlying layer on which the plating layer
is formed is an impurity-doped polysilicon film containing a high
concentration of impurities, when it is attempted to couple the
metal catalyst particles to the impurity-doped polysilicon film,
the aggregation of the metal catalyst particles such as palladium
may occur conspicuously. As a result, the metal catalyst particles
may not perform the function as the catalyst sufficiently, so that
the plating layer may not be formed sufficiently by a subsequent
electroless plating. Further, the aggregated metal catalyst
particles may become a hindrance when manufacturing a multilayer
substrate. Meanwhile, in case of performing the film (layer)
forming with the silane coupling agent (i.e., silane coupling
processing) as the underlying layer processing, since the layer of
the silane coupling agent may not necessarily be a monolayer, the
metal catalyst particles such as palladium used as the catalyst for
forming the plating layer may be covered with the silane coupling
agent, so that the metal catalyst particles coupled to the
underlying layer may not sufficiently function as the catalyst for
forming the plating layer and the plating layer may not be formed
efficiently.
SUMMARY
[0009] In view of the foregoing, exemplary embodiments provide a
substrate processing apparatus and a substrate processing method
capable of forming, without performing a silane coupling
processing, a catalyst layer on a substrate, which has an
impurity-doped polysilicon film containing a high concentration of
impurities on a surface thereof, by allowing palladium atoms to be
coupled to the impurity-doped polysilicon film of the substrate
without being aggregated. Further, the exemplary embodiments also
provide a recording medium having stored thereon a program for
implementing this substrate processing method.
[0010] The present inventors have reached the present disclosure by
finding out that, without performing a silane coupling processing
on a substrate having an impurity-doped polysilicon film containing
a high concentration of impurities on a surface thereof, a catalyst
layer can be formed on the substrate by allowing palladium atoms to
be coupled to the impurity-doped polysilicon film of the substrate
without being aggregated by using an alkaline liquid, as a catalyst
solution, containing a complex of a palladium ion and a monocyclic
5- or 6-membered heterocyclic compound having one or two nitrogen
atoms as a heteroatom. Further, the present inventors have found
out that, by observing with a scanning electron microscope and by
an X-ray photoelectron spectroscopy (XPS) analysis, the palladium
atoms are actually coupled to the impurity-doped polysilicon film
of the substrate without being aggregated by forming the catalyst
layer with this catalyst solution even if the siliane coupling
processing is not performed on the substrate. Furthermore, it is
also actually observed that a plating layer is formed by
electroless plating on the catalyst layer which is formed on the
substrate by using the aforementioned catalyst solution.
[0011] The present disclosure includes following exemplary
embodiments.
[0012] (1) A plasma processing apparatus configured to perform a
plating processing on a substrate having, on a surface thereof, an
impurity-doped polysilicon film containing a high concentration of
impurities, the substrate processing apparatus comprising:
[0013] a catalyst solution supply unit configured to supply, onto
the substrate, an alkaline catalyst solution containing a complex
of a palladium ion and a monocyclic 5- or 6-membered heterocyclic
compound having one or two nitrogen atoms as a heteroatom;
[0014] a plating liquid supply unit configured to supply a plating
liquid onto the substrate; and
[0015] a controller configured to control operations of the
catalyst solution supply unit and the plating liquid supply
unit,
[0016] wherein the controller controls the catalyst solution supply
unit and the plating liquid supply unit such that the catalyst
solution is supplied onto the substrate by the catalyst solution
supply unit and, after the catalyst solution is supplied, the
plating liquid is supplied onto the substrate by the plating liquid
supply unit.
[0017] (2) The substrate processing apparatus as described in
(1),
[0018] wherein the substrate further includes a base member and an
insulating film formed between the base member and the
impurity-doped polysilicon film.
[0019] (3) The substrate processing apparatus as described in (1)
or (2),
[0020] wherein the heterocyclic compound is selected from a group
consisting of pyrroline, pyrrole, imidazoline, imidazole,
pyrazoline, pyrazole, pyridine, pyridazine, pyrimidine, pyrazine,
pyrrolidine, imidazolidine, pyrazolidine, piperidine and
piperazine.
[0021] (4) The substrate processing apparatus as described in any
one of (1) to (3),
[0022] wherein the heterocyclic compound has a substituent selected
from a group consisting of a hydroxyl group, a carboxyl group and a
sulfate group.
[0023] (5) A substrate processing method of performing a plating
processing on a substrate having, on a surface thereof, an
impurity-doped polysilicon film containing a high concentration of
impurities, the substrate processing method comprising:
[0024] forming a catalyst layer by supplying, onto the substrate,
an alkaline catalyst solution containing a complex of a palladium
ion and a monocyclic 5- or 6-membered heterocyclic compound having
one or two nitrogen atoms as a heteroatom; and
[0025] forming a plating layer through electroless plating by
supplying a plating liquid onto the substrate after the forming of
the catalyst layer.
[0026] (6) The substrate processing method as described in (5),
[0027] wherein the substrate further includes a base member and an
insulating film formed between the base member and the
impurity-doped polysilicon film.
[0028] (7) The substrate processing method as described in (5) or
(6),
[0029] wherein the heterocyclic compound is selected from a group
consisting of pyrroline, pyrrole, imidazoline, imidazole,
pyrazoline, pyrazole, pyridine, pyridazine, pyrimidine, pyrazine,
pyrrolidine, imidazolidine, pyrazolidine, piperidine and
piperazine.
[0030] (8) The substrate processing method as described in any one
of (5) to (7),
[0031] wherein the heterocyclic compound has a substituent selected
from a group consisting of a hydroxyl group, a carboxyl group and a
sulfate group.
[0032] (9) A computer-readable recording medium having stored
thereon computer-executable instructions that, in response to
execution, cause a substrate processing apparatus to perform a
substrate processing method as described in any one of (5) to
(8).
[0033] According to the exemplary embodiments as stated above, it
is possible to provide a substrate processing apparatus and a
substrate processing method capable of forming, without performing
a silane coupling processing, a catalyst layer on a substrate
having an impurity-doped polysilicon film containing a high
concentration of impurities on a surface thereof, by allowing
palladium atoms to be coupled to the impurity-doped polysilicon
film of the substrate without being aggregated. Further, it is also
possible to provide a recording medium having stored thereon a
program for implementing this substrate processing method.
[0034] The foregoing summary is illustrative only and is not
intended to be in any way limiting. In addition to the illustrative
aspects, embodiments, and features described above, further
aspects, embodiments, and features will become apparent by
reference to the drawings and the following detailed
description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] In the detailed description that follows, embodiments are
described as illustrations only since various changes and
modifications will become apparent to those skilled in the art from
the following detailed description. The use of the same reference
numbers in different figures indicates similar or identical
items.
[0036] FIG. 1 is a schematic diagram illustrating a configuration
of a substrate processing apparatus according to an exemplary
embodiment;
[0037] FIG. 2 is a schematic plan view illustrating a configuration
of a substrate processing unit provided in the substrate processing
apparatus shown in FIG. 1;
[0038] FIG. 3 is a schematic cross sectional view illustrating a
configuration of a plating unit provided in the substrate
processing unit shown in FIG. 2; and
[0039] FIG. 4A to FIG. 4F are diagrams illustrating a process of a
substrate processing method performed by the substrate processing
apparatus shown in FIG. 1.
DETAILED DESCRIPTION
[0040] In the following detailed description, reference is made to
the accompanying drawings, which form a part of the description. In
the drawings, similar symbols typically identify similar
components, unless context dictates otherwise. Furthermore, unless
otherwise noted, the description of each successive drawing may
reference features from one or more of the previous drawings to
provide clearer context and a more substantive explanation of the
current exemplary embodiment. Still, the exemplary embodiments
described in the detailed description, drawings, and claims are not
meant to be limiting. Other embodiments may be utilized, and other
changes may be made, without departing from the spirit or scope of
the subject matter presented herein. It will be readily understood
that the aspects of the present disclosure, as generally described
herein and illustrated in the drawings, may be arranged,
substituted, combined, separated, and designed in a wide variety of
different configurations, all of which are explicitly contemplated
herein.
[0041] <Configuration of Substrate Processing Apparatus>
[0042] Referring to FIG. 1, a configuration of a substrate
processing apparatus according to an exemplary embodiment will be
explained. FIG. 1 is a schematic diagram illustrating the
configuration of the substrate processing apparatus according to
the exemplary embodiment.
[0043] As depicted in FIG. 1, the substrate processing apparatus 1
according to the exemplary embodiment includes a substrate
processing unit 2 and a controller 3 configured to control an
operation of the substrate processing unit 2.
[0044] The substrate processing unit 2 is configured to perform
various processings on a substrate. The various processings
performed by the substrate processing unit 2 will be described
later.
[0045] The controller 3 is implemented by, for example, a computer,
and includes a main controller and a storage unit. The main
controller is implemented by, for example, a CPU (Central
Processing Unit) and is configured to control the operation of the
substrate processing unit 2 by reading and executing a program
stored in the storage unit. The storage unit is implemented by a
storage device such as, but not limited to, a RAM (Random Access
Memory), a ROM (Read Only Memory) or a hard disk, and stores
thereon a program for controlling various processings performed in
the substrate processing unit 2. Further, the program may be
recorded in a computer-readable recording medium, or may be
installed from the recording medium to the storage unit. The
computer-readable recording medium may be, for example, a hard disc
(HD), a flexible disc (FD), a compact disc (CD), a magnet optical
disc (MO), or a memory card. The recording medium has stored
thereon a program that, when executed by a computer for controlling
an operation of the substrate processing apparatus 1, causes the
substrate processing apparatus 1 to perform a substrate processing
method to be described later under the control of the computer.
[0046] <Configuration of Substrate Processing Unit>
[0047] Referring to FIG. 2, a configuration of the substrate
processing unit 2 will be discussed. FIG. 2 is a schematic plan
view illustrating the configuration of the substrate processing
unit 2. In FIG. 2, dashed lines indicate substrates.
[0048] The substrate processing unit 2 is configured to perform
various processings on the substrate. A processing performed by the
substrate processing unit 2 is not particularly limited as long as
it includes: catalyst layer forming processing of forming a
catalyst layer on a substrate, which has an impurity-doped
polysilicon film formed on a surface thereof and containing a high
concentration of impurities, with an alkaline catalyst solution
(hereinafter, referred to as "catalyst solution of present
disclosure" or simply "catalyst solution") containing a complex of
a palladium ion and a monocyclic 5- or 6-membered aromatic or
aliphatic heterocyclic compound having one or two nitrogen atoms as
a heteroatom; and electroless plating processing of forming an
electroless plating layer on the catalyst layer which is formed by
the catalyst layer forming processing. Further, in the catalyst
layer forming processing, the catalyst layer is formed on the
impurity-doped polysilicon film of the substrate. The processing
performed by the substrate processing unit 2 may include various
other processings as well as the catalyst layer forming processing
and the electroless plating processing performed after the catalyst
layer forming processing. These various other processings may
include, for example, process processing, cleaning processing,
rinsing processing, baking processing, electroless copper (Cu)
plating processing, electrolytic copper (Cu) plating processing,
and so forth. The process processing may include a recess forming
processing of forming a recess for forming a conductive layer on a
base member, a film forming processing of forming an impurity-doped
polysilicon film at at least one main surface side (e.g., main
surface side where the recess is formed) of the base member, and so
forth. The forming processing is performed before the catalyst
layer forming processing, for example. The cleaning processing is a
processing of cleaning the substrate with a cleaning liquid and is
performed before and/or after the catalyst layer forming
processing, for example. The rinsing processing is a processing of
washing away various liquids remaining on the substrate with a
rinse liquid and is performed before subsequent processing is
performed after the cleaning processing. The baking processing is a
processing of baking the electroless plating layer which is formed
on the catalyst layer by the electroless plating processing. The
electroless Cu plating processing is a processing of forming an
electroless Cu plating layer on the electroless plating layer which
is formed on the catalyst layer by the electroless plating
processing. The formed electroless Cu plating layer serves as a
seed layer when performing the electrolytic Cu plating processing.
The electrolytic Cu plating processing is a processing of forming
an electrolytic Cu plating layer on the electroless Cu plating
layer (seed layer) which is formed by the electroless Cu plating
processing. One or more of these various other processings may be
performed in combinations.
[0049] In the present exemplary embodiment, a substrate having a
recess previously formed on a surface thereof is carried into the
substrate processing unit 2, and the various processings are
performed on the substrate. However, a base member on which the
process processing is not performed may be carried into the
substrate processing unit 2, and a substrate may be prepared by
performing the process processing of forming the recess on the
surface of the base member, a film forming processing of forming an
impurity-doped polysilicon film at at least one main surface side
(e.g., at the main surface side where the recess is formed) of the
base member, etc., in the substrate processing unit 2. Then, the
various processings may be performed. According to the present
exemplary embodiment, the substrate processing unit 2 is configured
to perform a processing including the catalyst layer forming
processing of forming the catalyst layer on a surface of the
substrate with the catalyst solution of the present disclosure and
the electroless plating processing of forming the electroless
plating layer on the catalyst layer which is formed on the surface
of the substrate by the catalyst layer forming processing.
[0050] The substrate processing unit 2 includes a carry-in/out
station 21; and a processing station 22 provided adjacent to the
carry-in/out station 21.
[0051] The carry-in/out station 21 includes a placing section 211;
and a transfer section 212 provided adjacent to the placing section
211.
[0052] In the placing section 211, a plurality of transfer
containers (hereinafter, referred to as "carriers C") is placed to
accommodate a plurality of substrates horizontally.
[0053] The transfer section 212 is provided with a transfer device
213 and a delivery unit 214. The transfer device 213 is provided
with a holding mechanism configured to hold a substrate. The
transfer device 213 is configured to be movable horizontally and
vertically, and pivotable around a vertical axis.
[0054] The processing station 22 includes a plurality of plating
units 4 configured to perform a processing including the catalyst
layer forming processing and the electroless plating processing on
the substrate. In the present exemplary embodiment, the number of
the plating units 4 provided in the processing station 22 may be
two or more, but it is also possible to provide only one plating
unit 4. In the present exemplary embodiment, the plating units 4
are arranged at both sides of a transfer path 211 which is extended
in a preset direction. However, the plating units 4 may be arranged
at one side of the transfer path 221. Furthermore, the substrate
processing unit 2 may be further equipped with a process processing
unit, a baking unit, an electroless Cu plating unit, an
electrolytic Cu plating unit, and so forth, which are configured to
perform the aforementioned process processing, baking processing,
electroless Cu plating processing and electrolytic Cu plating
processing, respectively.
[0055] The transfer path 221 is provided with a transfer device
222. The transfer device 222 includes a holding mechanism
configured to hold the substrate, and is configured to be movable
horizontally and vertically, and pivotable around the vertical
axis.
[0056] Now, as shown in FIG. 4A to FIG. 4F, an initial substrate
obtained before a substrate processing in the plating unit 4 (i.e.,
a substrate as a target of the substrate processing performed by
the plating unit 4) is referred to as "substrate W1" (FIG. 4A); a
substrate obtained after the catalyst layer forming processing of
forming a catalyst layer 91 on the surface of the substrate W1 is
referred to as "substrate W2" (FIG. 4B); and a substrate obtained
after the electroless plating processing of forming an electroless
plating layer 92 on the catalyst layer of the substrate W2 is
referred to as "substrate W3" (FIG. 4C). Further, in case that
various other processings are performed on the substrate W3
obtained after the electroless plating processing, a substrate
obtained after the electroless Cu plating processing of forming an
electroless Cu plating layer 93 on the electroless plating layer of
the substrate W3 is referred to as "substrate W4" (FIG. 4D); a
substrate obtained after the electrolytic Cu plating processing of
filing a recess of the substrate W4 with an electrolytic Cu plating
94 is referred to as "substrate W5" (FIG. 4E); and a substrate
obtained after a chemical mechanical polishing processing of
polishing a rear surface side (i.e., opposite from the surface
where the recess is formed) of the substrate W5 is referred to as
"substrate W6" (FIG. 4F).
[0057] In the substrate processing unit 2, the transfer device 213
of the carry-in/out station 21 is configured to transfer the
substrates W1 and W3 between the carriers C and the delivery unit
214. To elaborate, the transfer device 213 takes out the substrate
W1 from the carrier C placed in the placing section 211, and then,
places the substrate W1 in the delivery unit 214. Further, the
transfer device 213 takes out the substrate W3 which is placed in
the delivery unit 214 by the transfer device 222 of the processing
station 22, and then, accommodates the substrate W3 in the carrier
C of the placing section 211.
[0058] In the substrate processing unit 2, the transfer device 222
of the processing station 22 is configured to transfer the
substrates W1 and W3 between the delivery unit 214 and the plating
unit 4. To elaborate, the transfer device 222 takes out the
substrate W1 placed in the delivery unit 214, and then, carries the
substrate W1 into the plating unit 4. Further, the transfer device
222 takes out the substrate W3 from the plating unit 4, and then,
places the substrate W3 in the delivery unit 214.
[0059] <Configuration of Plating Unit>
[0060] Now, a configuration of the plating unit 4 will be explained
with reference to FIG. 3. FIG. 3 is a schematic cross sectional
view illustrating the configuration of the plating unit 4. In FIG.
3, "W" denotes any one of the aforementioned substrates W1 to W3
according to a processing stage of a substrate.
[0061] The plating unit 4 is configured to perform a processing
including: the catalyst layer forming processing of forming the
catalyst layer on the surface of the substrate W1 by using the
catalyst solution of the present disclosure; and the electroless
plating processing of forming the electroless plating layer on the
catalyst layer of the substrate W2 obtained after the catalyst
layer forming processing. Further, the processing performed by the
plating unit 4 is not particularly limited as long as it includes
the catalyst layer forming processing of forming the catalyst layer
on the surface of the substrate W1 by using the catalyst solution
of the present disclosure and the electroless plating processing of
forming the electroless plating layer on the catalyst layer of the
substrate W2 obtained after the catalyst layer forming processing.
Thus, the processing performed by the plating unit 4 may include
various other processings besides the catalyst layer forming
processing and the electroless plating processing which is
conducted after the catalyst layer forming processing. According to
the present exemplary embodiment, the plating unit 4 is equipped
with a cleaning liquid supply unit 43b and a rinse liquid supply
unit 43c as well as a catalyst solution supply unit 43a configured
to perform the catalyst layer forming processing on the surface of
the substrate W1 by supplying the catalyst solution onto the
substrate W1 and a plating liquid supply unit 45 configured to form
the electroless plating layer on the catalyst layer of the
substrate W2 by supplying a plating liquid for forming the
electroless plating layer on the substrate W2 obtained after the
catalyst layer forming processing. The cleaning liquid supply unit
43b is configured to supply a cleaning liquid for cleaning the
substrate, and the rinse liquid supply unit 43c is configured to
supply a rinse liquid for washing away various liquids remaining on
the substrate. The cleaning liquid supply unit 43b and the rinse
liquid supply unit 43c may be provided or may not be provided, and
the processings performed by these supply units may be performed by
other units.
[0062] The substrate W1 is not particularly limited as long as it
has an impurity-doped polysilicon film containing a high
concentration of impurities on a surface thereof. As an example, a
substrate having a base member and an impurity-doped polysilicon
film formed at at least one main surface side of the base member
may be used as the substrate W1. By way of example, a silicon wafer
or the like may be used as the base member. The base member may be
provided with a recess. In case that the base member has the
recess, it is desirable that the impurity-doped polysilicon film is
formed at a main surface side of the base member where the recess
is formed. The impurity-doped polysilicon film may be directly
formed on at least one main surface of the base member, or may be
formed at at least one main surface side of the base member with an
intermediate layer therebetween. That is, the substrate W1 may have
an intermediate layer formed between the base member and the
impurity-doped polysilicon film. The intermediate layer may be
implemented by, by way of example, an insulating film, and the
insulating film may be an interlayer insulating film such as a
SiO.sub.2 film, a SiN film, or a low dielectric film called a Low-k
film. The Low-k film may be a film having a dielectric constant
lower than a dielectric constant of silicon dioxide, for example, a
SiOC film. Further, the impurities contained in the impurity-doped
polysilicon film may not be particularly limited as long as it
applies electric conductivity to the polysilicon film. The
impurities may be, by way of example, but not limitation, atoms of
elements having a valence of 3, e.g., boron, atoms of elements
having a valence of 5, e.g., phosphorous, or the like. The
impurities contained in the impurity-doped polysilicon film may be
one kind of atoms or may be two or more kinds of atoms. Further,
regarding the amount of the impurities contained in the
impurity-doped polysilicon film, the term "high concentration"
means that the number of atoms as the impurities is equal to or
higher than 10.sup.15 per 1 cm.sup.3 of the impurity-doped
polysilicon film (10.sup.15/cm.sup.3). The amount of the impurities
contained in the impurity-doped polysilicon film is not
particularly limited as long as it is not less than
10.sup.15/cm.sup.3. In case that multiple kinds of atoms are
contained as the impurities, the aforementioned number of the
impurity atoms implies a sum of the individual numbers of the
multiple kinds of atoms.
[0063] The plating unit 4 includes a chamber 41, and is configured
to perform a substrate processing including the catalyst layer
forming processing and the electroless plating processing within
the chamber 41.
[0064] The plating unit 4 is provided with a substrate holding unit
42. The substrate holding unit 42 includes a rotation shaft 421
extended in the vertical direction within the chamber 41; a
turntable 422 provided at an upper end portion of the rotation
shaft 421; a chuck 423 provided on an outer peripheral portion of a
top surface of the turntable 422 and configured to support an edge
portion of the substrate W1; and a driving unit 424 configured to
rotate the rotation shaft 421.
[0065] The substrate W1 is supported by the chuck 423 to be
horizontally held by the turntable 422 while being slightly spaced
apart from the top surface of the turntable 422. In the present
exemplary embodiment, a mechanism of holding the substrate W1 by
the substrate holding unit 42 is of a so-called mechanical chuck
type in which the edge portion of the substrate W1 is held by the
chuck 423 which is configured to be movable. However, a so-called
vacuum chuck type of vacuum attracting a rear surface of the
substrate W1 may be employed instead.
[0066] A base end portion of the rotation shaft 421 is rotatably
supported by the driving unit 424, and a tip end portion of the
rotation shaft 421 sustains the turntable 422 horizontally. If the
rotation shaft 421 is rotated, the turntable 422 placed on the
upper end portion of the rotation shaft 421 is rotated, and, as a
result, the substrate W1 which is held on the turntable 422 by the
chuck 423 is also rotated. The controller 3 controls an operation
of the driving unit 424 to adjust, e.g., a rotation timing and a
rotational speed of the substrate W1.
[0067] The plating unit 4 is equipped with the catalyst solution
supply unit 43a, the cleaning liquid supply unit 43b and the rinse
liquid supply unit 43c configured to respectively supply a catalyst
solution L1, a cleaning liquid L2 and a rinse liquid L3 onto the
substrate W1 held by the substrate holding unit 42.
[0068] The catalyst solution supply unit 43a includes a nozzle 431a
configured to discharge the catalyst solution L1 onto the substrate
W1 held by the substrate holding unit 42; and a catalyst solution
supply source 432a configured to supply the catalyst solution L1 to
the nozzle 431a. The catalyst solution L1 is stored in a tank of
the catalyst solution supply source 432a, and the catalyst solution
L1 is supplied to the nozzle 431a from the catalyst solution supply
source 432a through a supply passageway 434a which is provided with
a flow rate controller such as a valve 433a.
[0069] The cleaning liquid supply unit 43b includes a nozzle 431b
configured to discharge the cleaning liquid L2 onto the substrate
W1 held by the substrate holding unit 42; and a cleaning liquid
supply source 432b configured to supply the cleaning liquid L2 to
the nozzle 431b. The cleaning liquid L2 is stored in a tank of the
cleaning liquid supply source 432b, and the cleaning liquid L2 is
supplied to the nozzle 431b from the cleaning liquid supply source
432b through a supply passageway 434b which is provided with a flow
rate controller such as a valve 433b.
[0070] The rinse liquid supply unit 43c includes a nozzle 431c
configured to discharge the rinse liquid L3 onto the substrate W1
held by the substrate holding unit 42; and a rinse liquid supply
source 432c configured to supply the rinse liquid L3 to the nozzle
431c. The rinse liquid L3 is stored in a tank of the rinse liquid
supply source 432c, and the rinse liquid L3 is supplied to the
nozzle 431c from the rinse liquid supply source 432c through a
supply passageway 434c which is provided with a flow rate
controller such as a valve 433c.
[0071] The catalyst solution L1, the cleaning liquid L2 and the
rinse liquid L3 are liquids for pre-processings that are performed
prior to the electroless plating processing with the plating liquid
M1.
[0072] The catalyst solution L1 as the catalyst solution of the
present disclosure contains a complex of a palladium ion and a
monocyclic 5- or 6-membered aromatic or aliphatic heterocyclic
compound having one or two nitrogen atoms as a heteroatom, and is
adjusted to be alkaline. Here, "alkaline" means that a pH thereof
is higher than 7. Desirably, it implies a pH 8 to a pH 14, and,
more desirably, a pH 8 to a pH 12. By adjusting the pH within this
range, the complex of the heterocyclic compound and the palladium
ion can be easily formed. By using the catalyst solution containing
this complex, it is possible to allow palladium atoms to be coupled
to the impurity-doped polysilicon film of the substrate without
being aggregated, so that a catalyst layer can be formed without
performing the processing with the silane coupling agent. Among the
heterocyclic compound constituting the complex together with the
palladium ion, the 5-membered aromatic compound may be, by way of
non-limiting example, pyrroline, pyrrole, imidazoline, imidazole,
pyrazoline, pyrazole, etc., and the 6-membered aromatic compound
may be, by way of non-limiting example, pyridine, pyridazine,
pyrimidine, pyrazine, etc. Further, the 5-membered aliphatic
compound may be, by way of example, pyrrolidine, imidazolidine,
pyrazolidine, etc., and the 6-membered aliphatic compound may be,
by way of non-limiting example, piperidine, piperazine, etc. If the
heterocyclic compound has position isomers, the individual position
isomers are also included. Further, the heterocyclic compound may
have a substituent. It is desirable that the substituent is a
hydrophilic group. The hydrophilic group may be, for example, a
hydroxyl group, a carboxyl group, a sulfate group, or the like. A
palladium ion source which supplies the palladium ions that
constitute the complex is not particularly limited as long as it is
capable of supplying the palladium ions. As such a palladium ion
source, palladium salt such as palladium chloride may be used.
Further, a solvent of the catalyst solution L1 is not particularly
limited, either, as long as it is capable of ionizing palladium. As
an example of the solvent of the catalyst solution L1, a polar
solvent capable of generating the palladium ions by dissolving the
palladium salt may be used. The polar solvent may be an organic
polar solvent or an inorganic polar solvent. Desirably, the polar
solvent may be water such as pure water.
[0073] Further, in case that the substrate W1 has the recess, it is
desirable to adjust a viscosity coefficient of the catalyst
solution L1 to diffuse the catalyst solution L1 sufficiently to a
lower portion of the recess.
[0074] As an example of the cleaning liquid L2, a malic acid, a
succinic acid, a citric acid or a malonic acid may be used.
[0075] As an example of the rinse liquid L3, pure water may be
used.
[0076] The plating unit 4 includes a nozzle moving mechanism 46
configured to move the nozzles 431a to 431c. The nozzle moving
mechanism 46 is equipped with an arm 461; a moving body 462 which
is configured to be movable along the arm 461 and has a moving
mechanism embedded therein; and a rotating/elevating mechanism 463
configured to rotate and move the arm 461 up and down. The nozzles
431a to 431c are provided at the moving body 462. The nozzle moving
mechanism 46 is capable of moving the nozzles 431a to 431c between
a position above the central portion of the substrate W1 held by
the substrate holding unit 42 and a position above the peripheral
portion of the substrate W1, and also capable of moving the nozzles
431a to 431c up to a stand-by position outside a cup 47 to be
described later. In the present exemplary embodiment, though the
nozzles 431a to 431c are held by the common arm, they may be
configured to be held by different arms and moved
independently.
[0077] The plating unit 4 includes a plating liquid supply unit 45
configured to supply the plating liquid M1 onto the substrate W1
which is held by the substrate holding unit 42. The plating liquid
supply unit 45 is equipped with a nozzle 451a configured to
discharge the plating liquid M1 toward the substrate W1 held by the
substrate holding unit 42; and a plating liquid supply source 452a
configured to supply the plating liquid M1 to the nozzle 451a. The
plating liquid M1 is stored in a tank of the plating liquid supply
source 452a, and the plating liquid M1 is supplied into the nozzle
451a through a supply passageway 454a.
[0078] The plating liquid M1 is an autocatalytic (reduction)
plating liquid for electroless plating. The plating liquid M1
contains a metal ion such as a cobalt (Co) ion, a nickel (Ni) ion,
a tungsten (W) ion; and a reducing agent such as hypophosphorous
acid or dimethylamineborane. Further, in the autocatalytic
(reduction) electroless plating, the metal ion in the plating
liquid M1 is reduced by the electrons emitted in an oxidation
reaction of the reducing agent in the plating liquid M1 and a metal
layer is precipitated. The plating liquid M1 may further contain an
additive or the like. The metal layer (plating layer) formed by the
plating with the plating liquid M1 may be, by way of non-limiting
example, CoWB, CoB, CoWP, CoWBP, NiWB, NiB, NiWP, NiWBP, or the
like. P in the plating layer is originated from the reducing agent
(e.g., hypophosphorous acid) containing P, and B in the plating
layer is originated from the reducing agent (e.g.,
dimethylamineborane) containing B.
[0079] A circulation passageway 457a provided with a pump 455a and
a first heating unit 456a is connected to the tank of the plating
liquid supply source 452a. The plating liquid M1 in the tank is
heated to a storage temperature while being circulated through the
circulation passageway 457a. Here, the "storage temperature" refers
to a temperature higher than a room temperature and lower than a
temperature (plating temperature) where the precipitation of the
metal ion in the plating liquid M1 progresses through a
self-reaction.
[0080] The supply passageway 454a is provided with a second heating
unit 458a configured to heat the plating liquid M1 to a discharge
temperature higher than the storage temperature. The second heating
unit 458a is further configured to heat the plating liquid M1,
which has been heated to the storage temperature by the first
heating unit 456a, up to the discharge temperature. Here, the
"discharge temperature" refers to a temperature equal to or higher
than the aforementioned plating temperature.
[0081] In the present exemplary embodiment, the plating liquid M1
is heated to a temperature equal to or higher than the plating
temperature in two stages by the first heating unit 456a and the
second heating unit 458a. Thus, as compared to the case where the
plating liquid M1 is heated to the temperature higher than the
plating temperature within the tank, evaporation of the components,
deactivation of the reducing agent in the plating liquid M1 or the
like can be suppressed. Therefore, a lifetime of the plating liquid
M1 can be lengthened. Further, as compared to the case where the
plating liquid M1 is stored at the room temperature within the tank
and then heated to the temperature equal to or higher than the
plating temperature by the second heating unit 458a later, it is
possible to heat the plating liquid M1 to the temperature equal to
or higher than the plating temperature rapidly with small energy,
so that the precipitation of the metal ion can be suppressed.
[0082] Various kinds of chemical liquids are supplied into the tank
of the plating liquid supply source 452a from a multiple number of
chemical liquid supply sources (not shown) which store various
kinds of components of the plating liquid M1. By way of example,
chemical liquids such as a CoSO.sub.4 metal salt containing a Co
ion, a reducing agent (e.g., hypophosphorous acid, etc.), and an
additive are supplied. At this time, flow rates of these chemical
liquids are adjusted such that the components of the plating liquid
M1 stored in the tank are appropriately controlled. A degassing
unit (not shown) configured to remove dissolved oxygen and
dissolved hydrogen in the plating liquid M1 may be provided in the
tank. The degassing unit is configured to supply an inert gas such
as, but not limited to, a nitrogen gas into the tank and dissolve
the inert gas such as the nitrogen gas in the plating liquid M1, so
that the other gases such as the oxygen and the hydrogen previously
dissolved in the plating liquid M1 may be discharged to the outside
of the plating liquid M1. The gases such as the oxygen and the
hydrogen discharged from the plating liquid M1 may be exhausted
from the tank by an exhaust unit (not shown). The circulation
passageway 457a may be provided with a filter (not shown). By
providing the filter in the circulation passageway 457a, various
kinds of impurities contained in the plating liquid M1 can be
removed when the plating liquid M1 is heated by the first heating
unit 456a. The circulation passageway 457a may be further provided
with a monitoring unit (not shown) configured to monitor a
characteristic of the plating liquid M1. The monitoring unit may be
implemented by, for example, a temperature monitoring unit
configured to monitor a temperature of the plating liquid M1, a pH
monitoring unit configured to monitor a pH of the plating liquid
M1, or the like.
[0083] The plating unit 4 is equipped with a nozzle moving
mechanism 44 configured to move the nozzle 451a. The nozzle moving
mechanism 44 includes an arm 441; a moving body 442 which is
configured to be movable along the arm 441 and has a moving
mechanism embedded therein; and a rotating/elevating mechanism 443
configured to rotate and move the arm 441 up and down. The nozzle
451a is provided at the moving body 442. The nozzle moving
mechanism 44 is capable of moving the nozzle 451a between a
position above a central portion of the substrate W1 held by the
substrate holding unit 42 and a position above a peripheral portion
of the substrate W1, and also capable of moving the nozzle 451a up
to a stand-by position outside the cup 47 to be described
later.
[0084] The plating unit 4 is equipped with the cup 47 having drain
openings 471a, 471b and 471c. The cup 47 is disposed around the
substrate holding unit 42, and is configured to collect various
kinds of processing liquids (e.g., plating liquid, cleaning liquid,
rinse liquid, catalyst solution, etc.) which are scattered from the
substrate W1. The cup 47 is provided with an elevating mechanism 48
configured to move the cup 47 up and down; and liquid draining
mechanisms 49a, 49b and 49c configured to collect and drain the
various kinds of processing liquids scattered from the substrate W1
through the drain openings 471a, 471b and 471c, respectively. By
way of example, the plating liquid M1 scattered from the substrate
W1 is drained from the liquid draining mechanism 49a; the catalyst
solution L1 scattered from the substrate W1 is drained from the
liquid draining mechanism 49b; and the cleaning liquid L2 and the
rinse liquid L3 scattered from the substrate W1 are drained from
the liquid draining mechanism 49c.
[0085] <Substrate Processing Method>
[0086] Now, a substrate processing method performed by the
substrate processing apparatus 1 will be discussed with reference
to FIG. 4A to FIG. 4F. FIG. 4A to FIG. 4C are schematic cross
sectional views illustrating a substrate on which the substrate
processing method is performed. In FIG. 4A to FIG. 4F, "S" denotes
the base member (e.g., silicon wafer), and "90" denotes the
impurity-doped polysilicon film.
[0087] The substrate processing method is performed on a substrate
W1 having a base member S provided with a recess 9a and an
impurity-doped polysilicon film 90 formed on an outermost layer of
one main surface side (main surface side where the recess 9a is
formed) of the base member S by the substrate processing apparatus
1. The present substrate processing method includes: a catalyst
layer forming process of forming a catalyst layer 91 on the
impurity-doped polysilicon film 90 of the substrate W1 with the
catalyst solution of the present disclosure; and an electroless
plating process of forming, through the electroless plating
processing, an electroless plating layer 92 on the catalyst layer
91 which is formed on the impurity-doped polysilicon film 90 of the
substrate W1 by the catalyst layer forming process. In the present
exemplary embodiment, the catalyst layer forming process and the
electroless plating process are performed by a single plating unit
4. However, these two processes may be performed by separate
processing units. An operation of the plating unit 4 is controlled
by the controller 3.
[0088] First, as shown in FIG. 4A, there is prepared the substrate
W1 having the base member S provided with the recess 9a and the
impurity-doped polysilicon film 90 formed on the outermost layer of
the one main surface side (main surface side where the recess 9a is
formed) of the base member S. In the present exemplary embodiment,
the substrate having the base member S with the recess 9a, which is
previously formed on the surface thereof, for forming the
conductive layer and the impurity-doped polysilicon film 90 formed
on the outermost layer of the one main surface side (main surface
side where the recess 9a is formed) of the base member S is used as
the substrate W1. However, the substrate processing method
performed by the substrate processing apparatus 1 may include a
processing of forming the recess 9a for forming the conductive
layer on the base member S, a processing of forming the
impurity-doped polysilicon film on one main surface (main surface
where the recess 9a is formed) of the base member S directly or at
the one main surface side with an intermediate layer (e.g.,
insulating film) therebetween, and so forth. As a method of forming
the recess 9a on the impurity-doped polysilicon film 90, a commonly
known method in the art may be appropriately employed.
Specifically, as a dry etching technique, for example, a
general-purpose technique using a fluorine-based gas or a
chlorine-based gas may be employed. Especially, in order to form a
hole having a high aspect ratio (hole depth/hole diameter), a
method using an ICP-RIE (Inductively Coupled Plasma Reactive Ion
Etching) technique, which can perform a deep etching process with a
high speed, may be more appropriately adopted. Especially, a Bosch
process in which an etching process using sulfur hexafluoride and a
protection process using a fluorine-based gas such as
C.sub.4F.sub.8 are repeatedly performed may be appropriately
utilized.
[0089] The substrate W1 is carried into the plating unit 4. At this
time, the transfer device 213 takes out the substrate W1 from the
carrier C placed in the placing section 211 and places the
substrate W1 in the delivery unit 214. The transfer device 222
takes out the substrate W1 from the delivery unit 214 and carries
the substrate W1 into the plating unit 4.
[0090] The substrate W1 which is carried into the plating unit 4 is
held by the substrate holding unit 42. At this time, the substrate
holding unit 42 holds the substrate W1 on the turntable 422
horizontally while the edge portion of the substrate W1 is
supported by the chuck 423. The driving unit 424 rotates the
substrate W1 held by the substrate holding unit 42 at a preset
speed. The controller 3 controls the driving unit 424 to adjust,
e.g., a rotation timing and a rotation speed of the substrate
W1.
[0091] In the plating unit 4, there is performed the catalyst layer
forming process of processing the substrate W1 held by the
substrate holding unit 42 with the catalyst solution L1 of the
present disclosure. By the catalyst layer forming process, the
catalyst layer 91 is formed on the impurity-doped polysilicon film
90 of the substrate W1, as shown in FIG. 4B. The catalyst solution
L1 is the same as described above. By processing the substrate W1
with the catalyst solution L1 of the present disclosure, palladium
atoms can be coupled to the impurity-doped polysilicon film of the
substrate W1 without being aggregated, so that the catalyst layer
91 can be formed without performing the silane coupling
processing.
[0092] In the catalyst layer forming process, while rotating the
substrate W1 held by the substrate holding unit 42 at a preset
speed, the nozzle 431a of the catalyst solution supply unit 43a is
placed at a position above a center of the substrate W1, and the
catalyst solution L1 is supplied onto the substrate W1 from the
nozzle 431a. At this time, the controller 3 controls an operation
of the catalyst solution supply unit 43a to adjust, e.g., a supply
timing, a supply time and a supply amount of the catalyst solution
L1. The catalyst solution L1 supplied onto the substrate W1 is
diffused onto a surface of the impurity-doped polysilicon film 90
of the substrate W1 by a centrifugal force generated when the
substrate W1 is rotated. As a result, the catalyst layer 91 is
formed on the entire surface of the impurity-doped polysilicon film
90 of the substrate W1. The catalyst solution L1 scattered from the
substrate W1 is drained through the drain opening 471b of the cup
47 and the liquid draining mechanism 49b. Upon the completion of
the catalyst layer forming process, a substrate W2 is obtained.
[0093] It is desirable to perform a cleaning process on the
substrate W1 in the plating unit 4 before the catalyst layer
forming process is performed on the substrate W1. In the cleaning
process, while rotating the substrate W1 held by the substrate
holding unit 42 at a preset speed, the nozzle 431b of the cleaning
liquid supply unit 43b is placed at the position above the central
portion of the substrate W1, and the cleaning liquid L2 is supplied
onto the substrate W1 from the nozzle 431b. At this time, the
controller 3 controls the cleaning liquid supply unit 43b to
adjust, e.g., a supply timing, a supply time and a supply amount of
the cleaning liquid L2. The cleaning liquid L2 supplied on the
substrate W1 is diffused onto the surface of the substrate W1 by a
centrifugal force generated when the substrate W1 is rotated. As a
result, contaminants or various kinds of processing liquids
remaining on the substrate W1 are washed away. The cleaning liquid
L2 is the same as described above. The cleaning liquid L2 scattered
from the substrate W1 is drained through the drain opening 471c of
the cup 47 and the liquid draining mechanism 49c.
[0094] Furthermore, it is desirable to perform the cleaning process
on the substrate W2 in the plating unit 4 upon the completion of
the catalyst layer forming process. In the cleaning process upon
the substrate W2, the same process as conducted on the substrate W1
is performed.
[0095] Furthermore, it is desirable to perform a rinse process in
the plating unit 4 before the catalyst layer forming process is
performed after the cleaning process upon the substrate W1. In the
rinse process, while rotating the substrate W1 held by the
substrate holding unit 42 at a preset speed, the nozzle 431c of the
rinse liquid supply unit 43c is located at the position above the
central portion of the substrate W1, and the rinse liquid L3 is
supplied onto the substrate W1 from the nozzle 431c. At this time,
the controller 3 controls an operation of the rinse liquid supply
unit 43c to adjust, e.g., a supply timing, a supply time and a
supply amount of the rinse liquid L3. The rinse liquid L3 supplied
on the substrate W1 is diffused onto the surface of the substrate
W1 by a centrifugal force generated when the substrate W1 is
rotated. As a result, the cleaning liquid L2 remaining on the
substrate W1 is washed away. The rinse liquid L3 is the same as
described above. The rinse liquid L3 scattered from the substrate
W1 is drained through the drain opening 471c of the cup 47 and the
liquid draining mechanism 49c.
[0096] In addition, it is desirable to perform a rinse process in
the plating unit 4 before a next process is performed after the
cleaning process upon the substrate W2. In this rinse process upon
the substrate W2, the same rinse process as conducted on the
substrate W1 is performed.
[0097] After the catalyst layer forming process (after the cleaning
process and/or the rinse process in case that these processes are
performed after the catalyst layer forming process), an electroless
plating process of forming an electroless plating layer 92 on the
catalyst layer 91 formed on the surface of the substrate W2 by the
electroless plating processing is performed in the plating unit 4.
Through the electroless plating process, the electroless plating
layer 92 is formed on the catalyst layer 91, as depicted in FIG.
4C. In the electroless plating process, while rotating the
substrate W2 held by the substrate holding unit 42 at a preset
speed, the nozzle 451a of the plating liquid supply unit 45 is
placed at a position above a central portion of the substrate W2,
and the plating liquid M1 is supplied onto the substrate W2 from
the nozzle 451a. At this time, the controller 3 controls an
operation of the plating liquid supply unit 45 to adjust, e.g., a
supply timing, a supply time and a supply amount of the plating
liquid M1. The plating liquid M1 supplied on the substrate W2 is
diffused onto the surface of the substrate W2 by a centrifugal
force generated when the substrate W2 is rotated. As a result, the
electroless plating layer 92 is formed on the catalyst layer 91
which is formed on the surface of the substrate W2. The plating
liquid M1 scattered from the substrate W2 is drained through the
drain opening 471a of the cup 47 and the liquid draining mechanism
49a. Upon the completion of the electroless plating process, a
substrate W3 is obtained.
[0098] The supply amount and the supply time of the plating liquid
M1 in the electroless plating process are appropriately adjusted
depending on a thickness of the electroless plating layer 92 to be
formed. For example, by supplying the plating liquid M1 onto the
substrate W2, an initial plating layer can be formed on the
catalyst layer 91 which is formed on the surface of the substrate
W2. By continuing to supply the plating liquid M1 onto the
substrate W2, a plating reaction further progresses on the initial
plating layer, so that the electroless plating layer 92 having a
required thickness is obtained. The formed electroless plating
layer 92 serves as a barrier layer configured to suppress a
diffusion of a Cu plating layer that is formed in processes shown
in FIG. 4D to FIG. 4F to be described later.
[0099] In the plating unit 4, it is desirable to perform a drying
process of drying the substrate W3 after the electroless plating
process. In the drying process, the substrate W3 may be dried
naturally or may be dried by rotating the substrate W3 or by
discharging a drying solvent or a drying gas to the substrate
W3.
[0100] The substrate W3 obtained after performing the substrate
processing in the plating unit 4 may be carried out from the
plating unit 4, or may be subjected to an additional processing to
be described later. In case that the substrate W3 is carried out
from the plating unit 4, the transfer device 222 takes out the
substrate W3 from the plating unit 4 and places the substrate W3 in
the delivery unit 214. The transfer device 213 takes out the
substrate W3 which is placed in the delivery unit 214 by the
transfer device 222, and accommodates the substrate W3 in the
carrier C of the placing section 211.
[0101] Now, an example of the additional processing that is
performed on the substrate W3 after the substrate W3 is processed
according to the substrate processing method performed by the
substrate processing apparatus 1 will be explained with reference
to FIG. 4D to FIG. 4F. FIG. 4D to FIG. 4F are schematic cross
sectional views illustrating a substrate on which individual
processings to be described later are performed after being
processed according to the substrate processing method performed by
the substrate processing apparatus 1. In FIG. 4A to FIG. 4F, the
substrates W1 to W3 are the same as described above. Further, in
FIG. 4A to FIG. 4F, a substrate obtained after forming an
electroless Cu plating layer 93 on the electroless plating layer 92
of the substrate W3 by an electroless Cu plating process is
referred to as "substrate W4"; a substrate obtained after filling
the recess 9a of the substrate W4 with an electrolytic Cu plating
94 by an electrolytic Cu plating process while using the
electroless Cu plating layer 93 on the substrate W4 as a seed layer
is referred to as "substrate W5"; and a substrate obtained after
chemically/mechanically polishing a rear surface side (i.e.,
opposite from the surface where the recess 9a is formed) of the
substrate W5 is referred to as "substrate W6".
[0102] The substrate W3 (FIG. 4C) processed according to the
substrate processing method performed by the substrate processing
apparatus 1 may be subjected to a baking process of baking the
electroless plating layer 92 after the electroless plating process
in the plating unit 4. The baking process is performed by heating
the substrate W3 on a hot plate within a sealed casing maintained
in an inert gas atmosphere filled with an N.sub.2 gas. Accordingly,
the electroless plating layer 92 of the substrate W3 is baked.
Desirably, a baking temperature for baking the electroless plating
layer 92 may be in the range from 150.degree. C. to 200.degree. C.,
and a baking time may be in the range from 10 min to 30 min. By
baking the electroless plating layer 92 on the substrate W3 as
stated above, moisture within the electroless plating layer 92 can
be removed, and, at the same time, intermetallic bonding within the
electroless plating layer 92 can be improved.
[0103] Furthermore, after performing the baking process on the
electroless plating layer 92, it may be possible to perform an
electroless Cu plating process (FIG. 4D) of forming an electroless
Cu plating layer 93 serving as a seed layer on the electroless
plating layer 92, serving as the barrier layer, which is formed on
the catalyst layer 91 by the electroless plating process. After the
electroless Cu plating process is completed, the substrate W4 is
obtained. Further, there may also be performed the electrolytic Cu
plating process (FIG. 4E) of filling the recess of the substrate
with the electrolytic Cu plating 94 by using the electroless Cu
plating layer 93 as a seed layer. After the electrolytic Cu plating
process is completed, the substrate W5 is obtained. In addition, a
chemical/mechanical polishing process (FIG. 4F) of
chemically/mechanically polishing the rear surface side (opposite
from the surface where the recess 9a is formed) of the substrate W5
may also be performed. After the chemical/mechanical polishing
process is finished, the substrate W6 is obtained.
[0104] From the foregoing, it will be appreciated that various
embodiments of the present disclosure have been described herein
for purposes of illustration, and that various modifications may be
made without departing from the scope and spirit of the present
disclosure. Accordingly, the various embodiments disclosed herein
are not intended to be limiting.
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