U.S. patent application number 15/333303 was filed with the patent office on 2017-05-04 for plating apparatus, plating method and recording medium.
The applicant listed for this patent is Tokyo Electron Limited. Invention is credited to Yuichiro Inatomi, Mitsuaki Iwashita, Nobutaka Mizutani.
Application Number | 20170121822 15/333303 |
Document ID | / |
Family ID | 58634483 |
Filed Date | 2017-05-04 |
United States Patent
Application |
20170121822 |
Kind Code |
A1 |
Mizutani; Nobutaka ; et
al. |
May 4, 2017 |
PLATING APPARATUS, PLATING METHOD AND RECORDING MEDIUM
Abstract
A plating apparatus can suppress a time period during which a
plating liquid is used in a plating from being reduced. In the
plating apparatus 1, after a plating liquid supply unit 53
supplies, to a substrate W1, a plating liquid which exerts a preset
plating performance within a preset concentration range and which
has an initial temperature adjusted to be lower than a preset
plating temperature; and an initial concentration adjusted such
that a concentration of the plating liquid at a moment when a
temperature of the plating liquid has reached the preset plating
temperature is equal to or higher than a lower limit of the preset
concentration range and equal to or below a median value of the
preset concentration range, a plating liquid heating unit 63 heats
the plating liquid supplied to the substrate W1 to the preset
plating temperature.
Inventors: |
Mizutani; Nobutaka;
(Nirasaki City, JP) ; Iwashita; Mitsuaki;
(Nirasaki City, JP) ; Inatomi; Yuichiro; (Nirasaki
City, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Tokyo Electron Limited |
Tokyo |
|
JP |
|
|
Family ID: |
58634483 |
Appl. No.: |
15/333303 |
Filed: |
October 25, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 18/1675 20130101;
C23C 18/1683 20130101; C23C 18/1676 20130101; C23C 18/31 20130101;
C23C 18/1619 20130101; C23C 18/168 20130101; C23C 18/52
20130101 |
International
Class: |
C23C 18/16 20060101
C23C018/16; C23C 18/52 20060101 C23C018/52; C23C 18/31 20060101
C23C018/31 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 28, 2015 |
JP |
2015-212218 |
Claims
1. A plating apparatus having a plating device configured to
perform a plating on a substrate at a preset plating temperature;
and a controller configured to control an operation of the plating
device, wherein the plating device comprises: a plating liquid
supply unit configured to supply, to the substrate, a plating
liquid which allowed to exert a preset plating performance within a
preset concentration range; and a plating liquid heating unit
configured to heat the plating liquid supplied to the substrate to
the preset plating temperature, wherein the plating liquid supplied
to the substrate from the plating liquid supply unit has an initial
temperature adjusted to be lower than the preset plating
temperature, and an initial concentration adjusted such that a
concentration of the plating liquid at a moment when a temperature
of the plating liquid has reached the preset plating temperature
while being heated by the plating liquid heating unit is equal to
or higher than a lower limit of the preset concentration range and
equal to or below a median value of the preset concentration range,
and the controller controls the plating liquid supply unit and the
plating liquid heating unit to perform, by supplying a preset
amount of the plating liquid to the substrate a single time and
heating the supplied plating liquid to the preset plating
temperature, the plating with the plating liquid heated to the
preset plating temperature.
2. The plating apparatus of claim 1, wherein the initial
concentration is adjusted such that the concentration of the
plating liquid at the moment when the temperature of the plating
liquid has reached the preset plating temperature is close to the
lower limit of the preset concentration range.
3. The plating apparatus of claim 1, wherein the initial
concentration is adjusted to be lower than the lower limit of the
preset concentration range.
4. The plating apparatus of claim 1, wherein the plating device is
equipped with a top plate disposed above the substrate, and when
the plating liquid supplied to the substrate is heated by the
plating liquid heating unit, a space in which vapor generated from
the plating liquid supplied to the substrate stays is formed
between the substrate and the top plate.
5. A plating method of performing a plating on a substrate at a
preset plating temperature, the plating method comprising: a
plating liquid supplying process of supplying, to the substrate, a
plating liquid which exerts a preset plating performance within a
preset concentration range and which has an initial temperature
adjusted to be lower than the preset plating temperature; and an
initial concentration adjusted such that a concentration of the
plating liquid at a moment when a temperature of the plating liquid
has reached the preset plating temperature is equal to or higher
than a lower limit of the preset concentration range and equal to
or below a median value of the preset concentration range; and a
plating liquid heating process of heating the plating liquid
supplied to the substrate to the preset plating temperature,
wherein a preset amount of the plating liquid is supplied to the
substrate a single time in the plating liquid supplying process,
and in the plating liquid heating process, the plating liquid
supplied in the plating liquid supplying process is heated to the
preset plating temperature, and the plating is performed with the
plating liquid heated to the preset plating temperature.
6. The plating method of claim 5, wherein the initial concentration
is adjusted such that the concentration of the plating liquid at
the moment when the temperature of the plating liquid has reached
the preset plating temperature is close to the lower limit of the
preset concentration range.
7. The plating method of claim 5, wherein the initial concentration
is adjusted to be lower than the lower limit of the preset
concentration range.
8. The plating method of claim 5, wherein the plating liquid
heating process is performed in a state where a space in which
vapor generated from the plating liquid supplied to the substrate
stays is formed between the substrate and a top plate disposed
above the substrate.
9. A computer-readable recording medium having stored thereon
computer-executable instructions that, in response to execution,
cause a plating apparatus to perform a plating method as claimed in
claim 5.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Japanese Patent
Application No. 2015-212218 filed on Oct. 28, 2015, the entire
disclosures of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The embodiments described herein pertain generally to a
plating apparatus and a plating method. Further, the embodiments
also relate to a recording medium having stored thereon a program
for performing the plating method.
BACKGROUND
[0003] A plating liquid exerts a preset plating performance within
a preset concentration range. When initially preparing the plating
liquid in a plating bath, the plating liquid is adjusted to have
the preset concentration range where the preset plating performance
is achieved from the beginning. Then, during a plating, the
concentration of the plating liquid is regulated to the preset
concentration range where the preset plating performance is
achieved. Patent Document 1 discloses a concentration management
method and a concentration management system for a plating
liquid.
[0004] Patent Document 2 describes a batch type plating apparatus.
In the batch type plating apparatus, a plating liquid adjusted to
have a preset concentration range where a preset plating
performance can be achieved is initially prepared in a plating
bath, and the plating upon a multiple number of substrates are
performed in the plating bath at the same time. If the
concentration of the plating liquid is decreased as a plating
component in the plating liquid is consumed through the plating,
the plating component is supplemented, and the plating is
repeatedly performed within the plating bath. In the batch type
plating apparatus, moisture is evaporated from the plating liquid
in the plating bath. Since, however, the amount of the plating
liquid in the plating bath is large, the decrease of the
concentration of the plating liquid caused by the consumption of
the plating component is more dominant than an increase of the
concentration of the plating liquid caused by the evaporation of
the moisture. Thus, the concentration of plating liquid in the
plating bath tends to be decreased.
[0005] Patent Document 3 describes a single-substrate type plating
apparatus. In the single-substrate type plating apparatus, a
plating liquid which is adjusted to have a preset concentration
range where a preset plating performance is achieved is supplied to
a single sheet of substrate, and a plating of the single sheet of
substrate is performed. The amount of the plating liquid supplied
to the single sheet of substrate is much smaller than the amount of
the plating liquid in the plating bath in the batch type plating
apparatus. Thus, the increase of the concentration of the plating
liquid caused by the evaporation of the moisture is more dominant
than the decrease of the concentration of the plating liquid caused
by the consumption of the plating component, so that the
concentration of the plating liquid supplied to the single sheet of
substrate tends to be increased.
[0006] Patent Document 1: Japanese Patent Laid-open Publication No.
2003-253453
[0007] Patent Document 2: Japanese Patent Laid-open Publication No.
2013-104118
[0008] Patent Document 3: Japanese Patent Laid-open Publication No.
2013-112845
[0009] In the single-substrate type processing apparatus, after a
plating liquid having an initial temperature adjusted to be below a
preset plating temperature and an initial concentration adjusted to
be in a preset concentration range where a preset plating
performance is achieved is supplied to a single sheet of substrate,
the supplied plating liquid is heated to the preset plating
temperature, and a plating is performed with the plating liquid
which is heated to the preset plating temperature. In this case,
during a time period before a temperature of the plating liquid
reaches the preset plating temperature, a plating component in the
plating liquid is hardly consumed, whereas moisture in the plating
liquid is evaporated. As a result, the concentration of the plating
liquid is increased. After the temperature of the plating liquid
reaches the preset plating temperature, the plating component in
the plating liquid is consumed. Since, however, the heating of the
plating liquid is continued, the concentration of the plating
liquid is increased. That is to say, since the increase of the
concentration of the plating liquid caused by the evaporation of
the moisture in the plating liquid is more dominant than the
decrease of the concentration of the plating liquid caused by the
consumption of the plating component in the plating liquid, the
concentration of the plating liquid increases even after the
temperature of the plating liquid reaches the preset plating
temperature. The plating liquid can be used until its concentration
reaches an upper limit of the preset concentration range. Since,
however, the concentration of the plating liquid is already
increased at a time when the temperature of the plating liquid has
reached the preset plating temperature, a time period before the
concentration of the plating liquid reaches the upper limit of the
preset concentration range, that is, a time period during which the
plating liquid can be used in the plating is shortened.
SUMMARY
[0010] In view of the foregoing, exemplary embodiments provide a
plating apparatus and a plating method capable of suppressing a
time period during which a plating liquid can be used in a plating
from being reduced. Further, the exemplary embodiments also provide
a recording medium having stored thereon a program for implementing
this plating method.
[0011] The present disclosure includes following exemplary
embodiments.
[0012] (1) A plating apparatus having a plating device configured
to perform a plating on a substrate at a preset plating
temperature; and a controller configured to control an operation of
the plating device,
[0013] wherein the plating device comprises:
[0014] a plating liquid supply unit configured to supply, to the
substrate, a plating liquid which allowed to exert a preset plating
performance within a preset concentration range; and [0015] a
plating liquid heating unit configured to heat the plating liquid
supplied to the substrate to the preset plating temperature, [0016]
wherein the plating liquid supplied to the substrate from the
plating liquid supply unit has an initial temperature adjusted to
be lower than the preset plating temperature, and an initial
concentration adjusted such that a concentration of the plating
liquid at a moment when a temperature of the plating liquid has
reached the preset plating temperature while being heated by the
plating liquid heating unit is equal to or higher than a lower
limit of the preset concentration range and equal to or below a
median value of the preset concentration range, and
[0017] the controller controls the plating liquid supply unit and
the plating liquid heating unit to perform, by supplying a preset
amount of the plating liquid to the substrate a single time and
heating the supplied plating liquid to the preset plating
temperature, the plating with the plating liquid heated to the
preset plating temperature.
[0018] (2) The plating apparatus as described in (1),
[0019] wherein the initial concentration is adjusted such that the
concentration of the plating liquid at the moment when the
temperature of the plating liquid has reached the preset plating
temperature is close to the lower limit of the preset concentration
range.
[0020] (3) The plating apparatus as described in (1) or (2),
[0021] wherein the initial concentration is adjusted to be lower
than the lower limit of the preset concentration range.
[0022] (4) The plating apparatus as described in any one of (1) to
(3),
[0023] wherein the plating device is equipped with a top plate
disposed above the substrate, and
[0024] when the plating liquid supplied to the substrate is heated
by the plating liquid heating unit, a space in which vapor
generated from the plating liquid supplied to the substrate stays
is formed between the substrate and the top plate.
[0025] (5) A plating method of performing a plating on a substrate
at a preset plating temperature, the plating method comprising:
[0026] a plating liquid supplying process of supplying, to the
substrate, a plating liquid which exerts a preset plating
performance within a preset concentration range and which has an
initial temperature adjusted to be lower than the preset plating
temperature; and an initial concentration adjusted such that a
concentration of the plating liquid at a moment when a temperature
of the plating liquid has reached the preset plating temperature is
equal to or higher than a lower limit of the preset concentration
range and equal to or below a median value of the preset
concentration range; and
[0027] a plating liquid heating process of heating the plating
liquid supplied to the substrate to the preset plating
temperature,
[0028] wherein a preset amount of the plating liquid is supplied to
the substrate a single time in the plating liquid supplying
process, and
[0029] in the plating liquid heating process, the plating liquid
supplied in the plating liquid supplying process is heated to the
preset plating temperature, and the plating is performed with the
plating liquid heated to the preset plating temperature.
[0030] (6) The plating method as described in (5),
[0031] wherein the initial concentration is adjusted such that the
concentration of the plating liquid at the moment when the
temperature of the plating liquid has reached the preset plating
temperature is close to the lower limit of the preset concentration
range.
[0032] (7) The plating method as described in (5) or (6),
[0033] wherein the initial concentration is adjusted to be lower
than the lower limit of the preset concentration range.
[0034] (8) The plating method as described in any one of (5) to
(7),
[0035] wherein the plating liquid heating process is performed in a
state where a space in which vapor generated from the plating
liquid supplied to the substrate stays is formed between the
substrate and a top plate disposed above the substrate.
[0036] (9) A computer-readable recording medium having stored
thereon computer-executable instructions that, in response to
execution, cause a plating apparatus to perform a plating method as
described in any one of (5) to (8).
[0037] According to the exemplary embodiments as stated above, it
is possible to provide a plating apparatus and a plating method
capable of suppressing the time period during which the plating
with the plating liquid is performed from being reduced. The
exemplary embodiments also provide a recording medium having stored
thereon a computer-executable program for implementing this plating
method.
[0038] 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
[0039] 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.
[0040] FIG. 1 is a schematic diagram illustrating a configuration
of a plating apparatus according to an exemplary embodiment;
[0041] FIG. 2 is a schematic plan view illustrating a configuration
of a plating unit included in the plating apparatus shown in FIG.
1; and
[0042] FIG. 3 is a schematic cross sectional view illustrating a
configuration of a plating device included in the plating unit
shown in FIG. 2.
DETAILED DESCRIPTION
[0043] 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.
[0044] <Configuration of Plating Apparatus>
[0045] Referring to FIG. 1, a configuration of a plating apparatus
according to an exemplary embodiment will be explained. FIG. 1 is a
schematic diagram illustrating the configuration of the plating
apparatus according to the exemplary embodiment.
[0046] As depicted in FIG. 1, the plating apparatus 1 according to
the exemplary embodiment includes a plating unit 2 and a controller
3 configured to control an operation of the plating unit 2.
[0047] The plating unit 2 is configured to perform various
processings on a substrate. The various processings performed by
the plating unit 2 will be described later.
[0048] The controller 3 is implemented by, for example, a computer,
and includes an operation controller and a storage unit. The
operation controller is implemented by, for example, a CPU (Central
Processing Unit) and is configured to control the operation of the
plating 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 plating 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 plating apparatus 1,
causes the plating apparatus 1 to perform a plating method to be
described later under the control of the computer.
[0049] <Configuration of Plating Unit>
[0050] Referring to FIG. 2, a configuration of the plating unit 2
will be discussed. FIG. 2 is a schematic plan view illustrating the
configuration of the plating unit 2. In FIG. 2, dashed lines
indicate substrates.
[0051] The plating unit 2 includes a carry-in/out station 21; and a
processing station 22 provided adjacent to the carry-in/out station
21.
[0052] The carry-in/out station 21 includes a placing section 211;
and a transfer section 212 provided adjacent to the placing section
211.
[0053] 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.
[0054] 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.
[0055] The processing station 22 includes plating devices 5. In the
present exemplary embodiment, the number of the plating devices 5
provided in the processing station 22 may be two or more, but it is
also possible to provide only one plating device 5. The plating
devices 5 are arranged at both side of a transfer path 221 which is
extended in a preset direction.
[0056] The transfer path 221 is provided with a transfer device
222. The transfer device 222 includes a holding mechanism
configured to hold a substrate, and is configured to be movable
horizontally and vertically and pivotable around a vertical
axis.
[0057] In the following description, a substrate before being
loaded into the plating device 5 will be referred to as "substrate
W0"; a substrate which has been loaded into the plating device 5
and is yet to be unloaded from the plating device 5 will be
referred to as "substrate W1"; and a substrate after being unloaded
from the plating device 5 will be referred to as "W2."
[0058] In the plating unit 2, the transfer device 213 of the
carry-in/out station 21 is configured to transfer the substrates W0
and W2 between the carriers C and the delivery unit 214. To
elaborate, the transfer device 213 takes out the substrate W0 from
the carrier C placed in the placing section 211, and then, places
the substrate W0 in the delivery unit 214. Further, the transfer
device 213 takes out the substrate W2 which is placed in the
delivery unit 214 by the transfer device 222 of the processing
station 22, and then, accommodates the substrate W2 in the carrier
C of the placing section 211.
[0059] In the plating unit 2, the transfer device 222 of the
processing station 22 is configured to transfer the substrates W0
and W2 between the delivery unit 214 and the plating device 5 and
between the plating device 5 and the delivery unit 214. To
elaborate, the transfer device 222 takes out the substrate W0
placed in the delivery unit 214 and carries the substrate W0 into
the plating device 5. Further, the transfer device 222 takes out
the substrate W2 from the plating device 5 and places the substrate
W2 in the delivery unit 214.
[0060] <Configuration of Plating Device>
[0061] Referring to FIG. 3, a configuration of the plating device 5
will be explained. FIG. 3 is a schematic cross sectional view
illustrating the configuration of the plating device 5.
[0062] The plating device 5 is configured to perform a plating on a
substrate W1 at a preset plating temperature. The plating performed
by the plating device 5 is an electroless plating. Here, a
substrate processing performed by the plating device 5 is not
particularly limited as long as it includes the plating. That is,
the substrate processing performed by the plating device 5 may
include other processings than the plating. In the present
exemplary embodiment, the substrate processing performed by the
plating device 5 includes the plating and a pre-processing which is
performed prior to the plating.
[0063] The plating device 5 includes a chamber 51, and is
configured to perform a substrate processing including the plating
within the chamber 51.
[0064] The plating device 5 is provided with a substrate holding
unit 52 configured to hold the substrate W1. The substrate holding
unit 52 includes a rotation shaft 521 extended in a vertical
direction within the chamber 51; a turntable 522 provided at an
upper end portion of the rotation shaft 521; a chuck 523 provided
on an outer peripheral portion of a top surface of the turntable
522 and configured to support an edge portion of the substrate W1;
and a driving unit 524 configured to rotate the rotation shaft
521.
[0065] The substrate W1 is supported by the chuck 523 to be
horizontally held on the turntable 522 while being slightly spaced
apart from the top surface of the turntable 522. In the present
exemplary embodiment, a mechanism of holding the substrate W1 by
the substrate holding unit 52 is of a so-called mechanical chuck
type in which the edge portion of the substrate W1 is held by the
chuck 523 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 used instead.
[0066] A base end portion of the rotation shaft 521 is rotatably
supported by the driving unit 524, and a leading end portion of the
rotation shaft 521 sustains the turntable 522 horizontally. If the
rotation shaft 521 is rotated, the turntable 522 placed on the
upper end portion of the rotation shaft 521 is rotated, and, as a
result, the substrate W1 which is held on the turntable 522 by the
chuck 523 is also rotated. The controller 3 controls the driving
unit 524 to adjust, e.g., a rotation timing, a rotational speed and
a rotation time of the substrate W1.
[0067] The plating device 5 includes a plating liquid supply unit
53 configured to supply a plating liquid M1 onto the substrate W1
which is held by the substrate holding unit 52. The plating liquid
supply unit 53 is equipped with a nozzle 531 configured to
discharge the plating liquid M1 toward the substrate W1 held by the
substrate holding unit 52; and a plating liquid supply source 532
configured to supply the plating liquid M1 to the nozzle 531. The
plating liquid M1 is stored in a tank of the plating liquid supply
source 532, and the plating liquid M1 is supplied into the nozzle
531 from the plating liquid supply source 532 through a supply
passageway 534 which is equipped with a flow rate controller such
as a valve 533. The controller 3 controls, for example, a supply
timing and a supply amount of the plating liquid M1 by controlling
the plating liquid supply unit 53.
[0068] 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, a copper (Cu) ion, a palladium (Pd) ion or a
gold (Au) 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 is precipitated as a
metal, so that a metal film (plating film) is formed. The plating
liquid M1 may further contain an additive or the like. The metal
film (plating film) 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 metal film (plating
film) is originated from the reducing agent (e.g., hypophosphorous
acid) containing P, and B in the plating film is originated from
the reducing agent (e.g., dimethylamineborane) containing B.
[0069] The plating liquid M1 supplied from the plating liquid
supply unit 53 (that is, the plating liquid M1 stored in the tank
of the plating liquid supply source 532) is a plating liquid which
conducts a preset plating performance within a preset concentration
range. It is determined, whether the plating liquid M1 exhibits the
preset plating performance, based on whether a metal film (plating
film) having a preset property (e.g., a thickness of 30 nm to 100
nm) is obtained when an electroless plating is performed by using a
preset amount of the plating liquid M1 at a preset plating
temperature for a predetermined time.
[0070] The plating liquid M1 contains a multiple number of
components. In order for the plating liquid M1 to provide the
preset plating performance, a concentration of each component needs
to be within a predetermined concentration range. That is, each of
the components contained in the plating liquid M1 has a
predetermined concentration range which is required for the plating
liquid M1 to exerts the preset plating performance. The
predetermined concentration range of each component is
appropriately determined based on a composition of the plating
liquid M1, and the like. Among all the components contained in the
plating liquid M1, a concentration of a component which has a
predetermined concentration range having a smallest difference
between an upper limit and a lower limit is defined as a
"concentration of the plating liquid M1." To elaborate, if the
component having the smallest difference between the upper limit
and the lower limit of the predetermined concentration range is a
metal ion forming the metal film (plating film), the concentration
of the metal ion is defined as "concentration of the plating liquid
M1" and the predetermined concentration range of the metal ion is
defined as the "preset concentration range of the plating liquid
M1." If the component having the smallest difference between the
upper limit and the lower limit of the predetermined concentration
range is a reducing agent, on the other hand, the concentration of
the reducing agent is defined as "concentration of the plating
liquid M1" and the predetermined concentration range of the
reducing agent is defined as the "preset concentration range of the
plating liquid M1." Here, the preset concentration range of the
plating liquid M1 is expressed as C.sub.L (%).about.C.sub.H
(%).
[0071] A concentration and a temperature of the plating liquid M1
supplied from the plating liquid supply unit 53 (that is, the
plating liquid M1 stored in the tank of the plating liquid supply
source 532) is referred to as "initial concentration" and "initial
temperature," and are distinguished from a concentration and a
temperature of the plating liquid M1 after being supplied from the
plating liquid supply unit 53 to the substrate W1 held by the
substrate holding unit 52.
[0072] After the plating liquid M1 is supplied from the plating
liquid supply unit 53 onto the substrate W1 held by the substrate
holding unit 52, the concentration and the temperature of the
plating liquid M1 are changed. The concentration of the plating
liquid M1 is changed as moisture in the plating liquid M1
evaporates and/or as a plating component in the plating liquid M1
is consumed. The temperature of the plating liquid M1 is changed as
the plating liquid M1 is heated by a plating liquid heating unit
63. To be specific, during a period from when the plating liquid M1
is supplied from the plating liquid supply unit 53 to the substrate
W1 held by the substrate holding unit 52 to when the supplied
plating liquid M1 reaches the preset plating temperature while
being heated by the plating liquid heating unit 63, the plating
component in the plating liquid M1 is hardly consumed, whereas the
moisture in the plating liquid M1 is evaporated. Thus, during this
period, the concentration of the plating liquid M1 is increased.
After the temperature of the plating liquid M1 has reached the
preset plating temperature, since the heating by the plating liquid
heating unit 63 is continued, the concentration of the plating
liquid M1 is still increased, though the plating component in the
plating liquid M1 is consumed. That is, since an increase of the
concentration of the plating liquid M1 caused by the evaporation of
the moisture in the plating liquid M1 is more dominant than a
decrease of the concentration of the plating liquid M1 caused by
the consumption of the plating component in the plating liquid M1,
the concentration of the plating liquid M1 is kept being increased
even after the temperature of the plating liquid M1 has reached the
preset plating temperature, and reaches the upper limit (i.e.,
C.sub.H (%)) of the preset concentration range, shortly.
[0073] The initial temperature of the plating liquid M1 is adjusted
to be below the preset plating temperature. The plating temperature
is a temperature where a plating reaction (a reaction in which the
metal ion in the plating liquid M1 is reduced by electrons emitted
through an oxidation reaction of the reducing agent in the plating
liquid M1 and is precipitated as a metal) progresses. For example,
the plating temperature may be, but not limited to, 60.degree. C.
to 70.degree. C. The initial temperature of the plating liquid M1
is, by way of non-limiting example, 23.degree. C. to 27.degree.
C.
[0074] The initial concentration of the plating liquid M1 is
adjusted such that the concentration of the plating liquid M1 at
the moment when the temperature of the plating liquid M1 has
reached the preset plating temperature is equal to or higher than
the lower limit (i.e., C.sub.L (%)) of the preset concentration
range and equal to or lower than a median value (i.e.,
(C.sub.L+C.sub.H)/2) of the preset concentration range.
[0075] Assume that the initial concentration of the plating liquid
M1 is X (%); the amount of the plating liquid M1 supplied from the
plating liquid supply unit 53 to the substrate W1 held by the
substrate holding unit 52 is Y (mL) (the plating liquid supply unit
53 does not supplement new plating liquid M1 until the plating with
the plating liquid M1 is completed after the preset amount of the
corresponding plating liquid M1 is once supplied); and the amount
of the moisture evaporated from the supplied plating liquid M1
during the period from when the plating liquid M1 is supplied from
the plating liquid supply unit 53 to the substrate W1 held by the
substrate holding unit 52 to when the temperature of the supplied
plating liquid M1 has reached the preset plating temperature while
being heated by the plating liquid heating unit 63 is Z (mL). The
concentration (%) of the plating liquid M1 at the time when the
temperature of the plating liquid M1 has reached the preset plating
temperature is expressed as (X.times.Y)/(Y-Z). Since the
concentration (%) of the plating liquid M1 at the time when it has
reached the preset plating temperature is equal to or higher than
C.sub.L and equal to or lower than (C.sub.L+C.sub.H)/2, an
expression of
C.sub.L.ltoreq.(X.times.Y)/(Y-Z).ltoreq.(C.sub.L+C.sub.H)/2 is
established. By modifying this expression, the initial
concentration X (%) of the plating liquid M1 is expressed as
C.sub.L(1-Z/Y).ltoreq..times..ltoreq.(C.sub.L+C.sub.H)(1-Z/Y)/2.
[0076] Since Z/Y is less than 1, a lower limit C.sub.L(1-Z/Y) of
the initial concentration (%) of the plating liquid M1 is less than
C.sub.L.
[0077] When there is established a relationship of
Z/Y=1-2C.sub.L/(C.sub.L+C.sub.H), an upper limit
(C.sub.L+C.sub.H)(1-Z/Y)/2 of the initial concentration (%) of the
plating liquid M1 is equal to C.sub.L.
[0078] When there is established a relationship of
Z/Y>1-2C.sub.L/(C.sub.L+C.sub.H), the upper limit
(C.sub.L+C.sub.H)(1-Z/Y)/2 of the initial concentration (%) of the
plating liquid M1 is less than C.sub.L.
[0079] When there is established a relationship of
Z/Y<1-2C.sub.L/(C.sub.L+C.sub.H), the upper limit
(C.sub.L+C.sub.H)(1-Z/Y)/2 of the initial concentration (%) of the
plating liquid M1 exceeds C.sub.L.
[0080] Accordingly, though the lower limit of the initial
concentration (%) of the plating liquid M1 is always less than
C.sub.L, the upper limit of the initial concentration (%) of the
plating liquid M1 may be less than C.sub.L, equal to C.sub.L or
exceed C.sub.L.
[0081] As the concentration of the plating liquid M1 at the time
when the temperature of the plating liquid M1 has reached the
preset plating temperature is closer to the lower limit (i.e.,
C.sub.L (%)) of the preset concentration range, a time period taken
until the concentration of the plating liquid M1 reaches the upper
limit (i.e., C.sub.H (%)) of the preset concentration range, that
is, a time period during which the plating liquid M1 can be used
for the plating is lengthened. In this aspect, the concentration of
the plating liquid M1 at the time when the temperature of the
plating liquid M1 has reached the preset plating temperature is
desirably set to be near the lower limit (i.e., C.sub.L(%)) of the
preset concentration range, and, more desirably, set to be the
lower limit (i.e., C.sub.L(%)) of the preset concentration
range.
[0082] The concentration of the plating liquid M1 at the time when
the temperature of the plating liquid M1 has reached the preset
plating temperature is larger than the initial concentration
thereof. Thus, if the initial concentration (%) of the plating
liquid M1 is equal to or higher than C.sub.L, it may be difficult
to adjust the concentration of the plating liquid M1 at the time
when the temperature of the plating liquid M1 has reached the
preset plating temperature to be close to the lower limit (i.e.,
C.sub.L (%)) of the preset concentration range. Therefore, it is
desirable that the initial concentration (%) of the plating liquid
M1 is less than the lower limit (i.e., C.sub.L (%)) of the preset
concentration range.
[0083] After supplying the preset amount of the plating liquid M1 a
single time, the plating liquid supply unit 53 does not supply new
plating liquid M1 until the plating with the supplied plating
liquid M1 is completed. Desirably, the preset amount of the plating
liquid M1 supplied from the plating liquid supply unit 53 at the
singe time is 20 mL to 200 mL and, more desirably, 30 mL to 100 mL
in case that the substrate W1 has a diameter of 300 mm. The plating
on a single sheet of substrate W1 is performed with the preset
amount of the plating liquid M1 which is supplied one time from the
plating liquid supply unit 53. That is, the plating on the single
sheet of substrate W1 is begun at the time when the plating liquid
M1 supplied to the substrate W1 reaches the plating temperature and
is finished at the time when the plating liquid M1 is drained from
the substrate W1. Further, the plating liquid M1 is drained from
the substrate W1 before the concentration of the plating liquid M1
reaches the upper limit (i.e., C.sub.H (%)) of the preset
concentration range. Since the temperature of the plating liquid M1
supplied from the plating liquid supply unit 53 is lower than the
preset plating temperature, the plating is not begun or, even if
begun, progresses very slowly at the time when the plating liquid
M1 is supplied from the plating liquid supply unit 53 to the
substrate W1 held by the substrate holding unit 52. After the
plating liquid M1 is supplied from the plating liquid supply unit
53 to the substrate W1 which is held by the substrate holding unit
52, the plating is begun at the time when the temperature of the
supplied plating liquid M1 reaches the preset plating temperature
while being heated by the plating liquid heating unit 63. During
the plating, the temperature of the plating liquid M1 is maintained
at the preset plating temperature by the plating liquid heating
unit 63. Accordingly, the plating is performed with the plating
liquid M1 which is heated to the preset plating temperature.
[0084] A circulation passageway 537 provided with a pump 535 and a
heating unit 536 is connected to the tank of the plating liquid
supply source 532. The plating liquid M1 in the tank is heated to a
storage temperature while being circulated through the circulation
passageway 537. 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. In the present exemplary embodiment, though the
plating liquid M1 in the tank is heated to the storage temperature,
the plating liquid M1 in the tank may be kept at a room
temperature. According to the exemplary embodiment, evaporation of
the components, deactivation of the reducing agent in the plating
liquid M1 or the like, which might occur in case where the plating
liquid M1 is heated to the plating temperature within the tank, can
be suppressed. Therefore, a lifetime of the plating liquid M1 can
be lengthened.
[0085] A chemical liquid L1 containing various components of the
plating liquid M1 is supplied into the tank of the plating liquid
supply source 532 from a chemical liquid supply source 538a which
stores the chemical liquid L1 through a supply passageway 538c
which is equipped with a flow rate controller 538b such as a valve.
Further, a diluent liquid L2 which dilutes the chemical liquid L1
is supplied into the tank of the plating liquid supply source 532
from a diluent liquid supply source 539a which stores the diluent
liquid L2 through a supply passageway 539c which is equipped with a
flow rate controller 539b such as a valve. The diluent liquid L2
is, for example, pure water. The chemical liquid L1 supplied from
the chemical liquid supply source 538a and the diluent liquid L2
supplied from the diluent liquid supply source 539a are mixed, so
that the plating liquid M1 is prepared. At this time, a flow rate
of the chemical liquid L1 is adjusted by the flow rate controller
538b and a flow rate of the diluent liquid L2 is adjusted by the
flow rate controller 539b such that the concentration of the
plating liquid M1 has the preset concentration.
[0086] In the present exemplary embodiment, though only one
chemical liquid L1 containing all the components of the plating
liquid M1 is used, it may be possible to use two or more chemical
liquids each of which contains a part of the components of the
plating liquid M1. Further, the components contained in each
chemical liquid are adjusted such that the two or more chemical
liquids contain all the components of the plating liquid M1 as a
whole. When using the two or more chemical liquids each containing
a part of the components of the plating liquid M1, the two or more
chemical liquids are supplied into the tank of the plating liquid
supply source 532 from corresponding two or more chemical liquid
supply sources storing the respective chemical liquids through
supply passageways each of which is equipped with flow rate
controller such as a valve. As the respective chemical liquids
supplied from the two or more chemical liquid supply sources and
the diluent liquid L2 supplied from the diluent liquid supply
source 539a are mixed in the tank, the plating liquid M1 is
prepared. At this time, flow rates of the respective chemical
liquids are adjusted by the corresponding flow rate controllers and
the flow rate of the diluent liquid L2 is adjusted by the flow rate
controller 539b such that the plating liquid M1 is allowed to have
the preset concentration.
[0087] A degassing unit (not shown) configured to remove dissolved
oxygen and dissolved hydrogen in the plating liquid M1 may be
provided in the tank of the plating liquid supply source 532. 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 537 may be provided with a filter (not shown). By
providing the filter in the circulation passageway 537, various
kinds of impurities contained in the plating liquid M1 can be
removed. The circulation passageway 537 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.
[0088] The plating device 5 is equipped with a nozzle moving
mechanism 54 configured to move the nozzle 531. The nozzle moving
mechanism 54 includes an arm 541; a moving body 542 which is
configured to be movable along the arm 541 and has a moving
mechanism embedded therein; and a rotating/elevating mechanism 543
configured to rotate and move the arm 541 up and down. The nozzle
531 is provided at the moving body 542. The nozzle moving mechanism
54 is capable of moving the nozzle 531 between a position above a
central portion of the substrate W1 held by the substrate holding
unit 52 and a position above a peripheral portion of the substrate
W1, and also capable of moving the nozzle 531 up to a stand-by
position outside a cup 57 to be described later when viewed from
the top. The controller 3 controls the nozzle moving mechanism 54
to adjust a moving timing, a moved position of the nozzle 531, and
so forth.
[0089] The plating device 5 includes a catalyst solution supply
unit 55a, a cleaning liquid supply unit 55b and a rinse liquid
supply unit 55c configured to supply a catalyst solution N1, a
cleaning liquid N2 and a rinse liquid N3 onto the substrate W1 held
by the substrate holding unit 52, respectively. Further, it may be
appropriately determined depending on the kind of the plating
liquid M1 whether to provide the catalyst solution supply unit 55a.
That is, depending on the kind of the plating liquid M1, the
catalyst solution supply unit 55a may be omitted.
[0090] The catalyst solution supply unit 55a includes a nozzle 551a
configured to discharge the catalyst solution N1 onto the substrate
W1 held by the substrate holding unit 52; and a catalyst solution
supply source 552a configured to supply the catalyst solution N1 to
the nozzle 551a. The catalyst solution N1 is stored in a tank of
the catalyst solution supply source 552a, and the catalyst solution
N1 is supplied to the nozzle 551a from the catalyst solution supply
source 552a through a supply passageway 554a which is provided with
a flow rate controller such as a valve 553a. The controller 3
controls the catalyst solution supply unit 55a to adjust a supply
timing of the catalyst solution N1, a supply amount thereof, and so
forth.
[0091] The cleaning liquid supply unit 55b includes a nozzle 551b
configured to discharge the cleaning liquid N2 onto the substrate
W1 held by the substrate holding unit 52; and a cleaning liquid
supply source 552b configured to supply the cleaning liquid N2 to
the nozzle 551b. The cleaning liquid N2 is stored in a tank of the
cleaning liquid supply source 552b, and the cleaning liquid N2 is
supplied to the nozzle 551b from the cleaning liquid supply source
552b through a supply passageway 554b which is provided with a flow
rate controller such as a valve 553b. The controller 3 controls the
cleaning liquid supply unit 55b to adjust a supply timing of the
cleaning liquid N2, a supply amount thereof, and so forth.
[0092] The rinse liquid supply unit 55c includes a nozzle 551c
configured to discharge the rinse liquid N3 onto the substrate W1
held by the substrate holding unit 52; and a rinse liquid supply
source 552c configured to supply the rinse liquid N3 to the nozzle
551c. The rinse liquid N3 is stored in a tank of the rinse liquid
supply source 552c, and the rinse liquid N3 is supplied to the
nozzle 551c from the rinse liquid supply source 552c through a
supply passageway 554c which is provided with a flow rate
controller such as a valve 553c. The controller 3 controls the
rinse liquid supply unit 55c to adjust a supply timing of the rinse
liquid N3, a supply amount thereof, and so forth.
[0093] The catalyst solution N1, the cleaning liquid N2 and the
rinse liquid N3 are pre-treatment liquids for pre-processings that
are performed prior to the plating with the plating liquid M1.
[0094] The catalyst solution N1 contains a metal ion (e.g., a
palladium (Pd) ion, a platinum (Pt) ion, a gold (Au) ion, etc.)
having catalytic activity to an oxidation reaction of the reducing
agent in the plating liquid M1. In the electroless plating, in
order to start precipitation of the metal ion in the plating liquid
M1, an initial film surface (that is, plating target surface of
substrate) needs to have sufficient catalytic activity to the
oxidation reaction of the reducing agent in the plating liquid M1.
Thus, depending on the kind of the plating liquid M1, it may be
desirable to process the plating target surface of the substrate
with the catalyst solution N1 and form a metal film having the
catalytic activity on the plating target surface of the substrate
before starting the plating with the plating liquid M1. It may be
appropriately determined depending on the kind of the plating
liquid M1 whether to perform the processing with the catalyst
solution N1 before starting the plating. That is, depending on the
kind of the plating liquid M1, the processing with the catalyst
solution N1 may be omitted. The metal film having the catalytic
activity is formed through a replacement reaction. In the
replacement reaction, a metal forming the plating target surface of
the substrate (e.g., copper in a copper wiring formed on the
plating target surface of the substrate) serves as the reducing
agent, and the metal ion (e.g., Pd ion) in the catalyst solution N1
is reduced to be precipitated on the plating target surface of the
substrate.
[0095] As an example of the cleaning liquid N2, an organic acid
such as a malic acid, a succinic acid, a citric acid or a malonic
acid, or hydrofluoric acid (DHF) (aqueous solution of hydrogen
fluoride) diluted to the extent that it does not corrode the
plating target surface of the substrate may be used.
[0096] As an example of the rinse liquid N3, pure water may be
used.
[0097] The plating device 5 includes a nozzle moving mechanism 56
configured to move the nozzles 551a to 551c. The nozzle moving
mechanism 56 is equipped with an arm 561; a moving body 562 which
is configured to be movable along the arm 561 and has a moving
mechanism embedded therein; and a rotating/elevating mechanism 563
configured to rotate and move the arm 561 up and down. The nozzles
551a to 551c are provided at the moving body 562. The nozzle moving
mechanism 56 is capable of moving the nozzles 551a to 551c between
a position above the central portion of the substrate W1 held by
the substrate holding unit 52 and a position above the peripheral
portion of the substrate W1, and also capable of moving the nozzles
551a to 551c up to a stand-by position outside the cup 57 to be
described later when viewed from the top. In the present exemplary
embodiment, though the nozzles 551a to 551c are held by the common
arm, they may be configured to be held by different arms and moved
independently. The controller 3 controls the nozzle moving
mechanism 56 to adjust moving timings, moved positions of the
nozzles 551a to 551c, and so forth by controlling.
[0098] The plating device 5 is equipped with the cup 57 having
drain openings 571a,571b and 571c. The cup 57 is disposed around
the substrate holding unit 52, and is configured to collect various
kinds of processing liquids (e.g., plating liquid, catalyst
solution, cleaning liquid, rinse liquid, etc.) which are scattered
from the substrate W1. The cup 57 is provided with an elevating
mechanism 58 configured to move the cup 57 up and down; and liquid
draining mechanisms 59a, 59b and 59c configured to collect and
drain the various kinds of processing liquids scattered from the
substrate W1 through the drain openings 571a,571b and 571c,
respectively. By way of example, the plating liquid M1 scattered
from the substrate W1 is drained from the liquid draining mechanism
59a; the catalyst solution N1 scattered from the substrate W1 is
drained from the liquid draining mechanism 59b; and the cleaning
liquid N2 and the rinse liquid N3 scattered from the substrate W1
are drained from the liquid draining mechanism 59c. The controller
3 controls the elevating mechanism 58 to adjust a moving timing, a
moved position of the cup 57, and so forth.
[0099] The plating device 5 is also equipped with a top plate 61
disposed above the substrate W1 held by the substrate holding unit
52; and an elevating mechanism 62 configured to move the top plate
61 in a vertical direction and in a horizontal direction. The top
plate 61 is disposed above the substrate W1 while being spaced
apart from the substrate W1. When viewed from the top, the top
plate 61 has a shape (e.g., a circular shape) corresponding to the
shape of the substrate W1, and the size of the top plate 61 is
adjusted to cover the substantially entire surface region of the
substrate W1. The shape and the size of the top plate 61 are not
particularly limited and can be appropriately modified as long as a
space can be formed between the substrate W1 and the top plate 61.
By way of example, when viewed from the top, the top plate 61 may
have a rectangular shape or the like. Further, the top plate 61 is
not provided with any through hole or opening which can serve a
flow path of vapor which is generated from the plating liquid M1.
The controller 3 controls the elevating mechanism 62 to adjust a
moving timing, a moved position of the top plate 61, and so forth
by controlling.
[0100] The top plate 61 is configured to be moved up and down by
the elevating mechanism 62 independently from the cup 57.
Accordingly, carrying-in and carrying-out of the substrate
onto/from the substrate holding unit 52 can be facilitated.
[0101] The elevating mechanism 62 is configured to move the top
plate 61 horizontally between a position where the top plate 61
covers the substantially entire surface region of the substrate W1
and a position where the top plate 61 does not cover the
substantially entire surface region of the substrate W1. Further,
the elevating mechanism 62 is capable of adjusting a distance
between the substrate W1 and the top plate 61 (i.e., a volume of a
space S formed between the substrate W1 and the top plate 61) by
moving the top plate 61 in the vertical direction after moving the
top plate 61 to the position where it covers the substantially
entire surface region of the substrate W1. After the top plate 61
is horizontally moved to the position where it does not cover the
substantially entire surface region of the substrate W1, the
liquids are supplied from the various nozzles to the substrate W1
held by the substrate holing unit 52. Further, after the top plate
61 is moved to the position where it covers the substantially
entire surface region of the substrate W1 and the distance between
the substrate W1 and the top plate 61 (i.e., the volume of the
space S formed between the substrate W1 and the top plate 61) is
adjusted, the plating liquid M1 supplied to the substrate W1 is
heated.
[0102] By adjusting the distance between the substrate W1 and the
top plate 61 after moving the top plate 61 to the position where
the top plate 61 covers the substantially entire surface region of
the substrate W1, the space S is formed between the substrate W1
held by the substrate holding unit 52 and the top plate 61 disposed
above the substrate W1. The space S is surrounded by the cup 57,
but is not sealed by the cup 57 and the space S communicates with
an external space (a space within the chamber 51). If the moisture
in the plating liquid M1 supplied to the substrate W1 held by the
substrate holding unit 52 is evaporated, the vapor generated from
the plating liquid M1 is flown out into the external space after
staying in the space S. Accordingly, the moisture in the plating
liquid M1 supplied to the substrate W1 held by the substrate
holding unit 52 is continuously evaporated. By adjusting the volume
of the space S (e.g., the distance between the substrate W1 held by
the substrate holding unit 52 and the top plate 61), an evaporation
amount of the moisture from the plating liquid M1 can be adjusted.
For example, by reducing the volume of the space S, the evaporation
amount of the moisture from the plating liquid M1 can be reduced.
Accordingly, a sharp increase of the concentration of the plating
liquid M1 caused by the evaporation of the moisture can be
suppressed. The moisture that stays in the space S serves as a heat
medium when heating, by the plating liquid heating unit 63, the
plating liquid M1 supplied onto the substrate W1 which is held by
the substrate holding unit 52. The distance between the substrate
W1 held by the substrate holding unit 52 and the top plate 61 is
appropriately adjusted based on a set temperature of the top plate,
a temperature of the plating liquid after being heated, a
temperature rising rate of the plating liquid, an amount of the
plating liquid on the substrate, and so forth.
[0103] The top plate 61 is equipped with the plating liquid heating
unit 63 configured to heat the plating liquid M1 supplied onto the
substrate W1 which is held by the substrate holding unit 52.
Further, the substrate W1 held by the substrate holding unit 52 is
also heated by the plating liquid heating unit 63. The plating
liquid heating unit 63 includes a heater such as a lamp heater
(e.g., a LED lamp heater) and a heating wire. In the present
exemplary embodiment, the heater of the plating liquid heating unit
63 is embedded within the top plate 61. In the present exemplary
embodiment, the plating liquid heating unit 63 heats the plating
liquid M1 on the substrate W1 from above the substrate W1 held by
the substrate holding unit 52. However, the plating liquid heating
unit 63 may be configured to heat the plating liquid M1 on the
substrate W1 from below the substrate W1 held by the substrate
holding unit 52. In this case, the plating liquid M1 on the
substrate W1 is heated by heating the substrate W1 held by the
substrate holding unit 52. By way of example, the plating liquid
heating unit 63 may be provided at the turntable 522 of the
substrate holding unit 52. The controller 3 controls the plating
liquid heating unit 63 to adjust a heating timing, a heating
temperature, a heating time, and so forth.
[0104] <Plating Method>
[0105] Now, a plating method performed by the plating apparatus 1
will be discussed. The plating method performed by plating
apparatus 1 includes a plating process of performing a plating on
the substrate W1. The plating in the plating process is performed
by the plating devices 5. An operation of the plating device 5 is
controlled by the controller 3. The plating method performed by the
plating apparatus 1 may further include other processes than the
plating process.
[0106] First, a substrate carry-in process is performed. In the
substrate carry-in process, the substrate W1 is carried into the
plating device 5. The controller 3 controls the transfer device 213
to take out a substrate W0 from a carrier C placed in the placing
section 211 and to place the taken substrate W0 in the delivery
unit 214. Then, the controller 3 controls the transfer device 222
to take out the substrate W0 placed in the delivery unit 214 and to
carry the taken substrate W0 into the plating device 5.
[0107] After the substrate carry-in process, a substrate holding
process is performed. In the substrate holding process, the
substrate W1 carried into the plating device 5 is held by the
substrate holding unit 52. The controller 3 controls the elevating
mechanism 58 to move the cup 57 down to a preset position, and also
controls the elevating mechanism 62 to move the top plate 61
horizontally to the position where it does not cover the
substantially entire surface region of the substrate W1.
Accordingly, the transfer device 222 is allowed to access the
substrate holding unit 52. The controller 3 controls the transfer
device 222 to place the substrate W1 on the substrate holding unit
52. The substrate W1 is horizontally placed on the turntable 522
while its periphery portion is held by the chuck 523.
[0108] After the substrate holding process, the plating process is
performed. The plating in the plating process is performed on the
substrate W1 held by the substrate holding unit 52. The plating
device 5 may perform a pretreatment process of pre-processing the
substrate W1 before the plating process. The pretreatment process
may include a cleaning process; and a first rinse process which is
performed after the cleaning process. Further, the pretreatment
process may also include a catalyst solution supplying process
which is performed after the first rinse process. Furthermore, the
pretreatment process may further include a second rinse process
which is performed after the catalyst solution supplying
process.
[0109] In the cleaning process, the substrate W1 held by the
substrate holding unit 52 is cleaned. While rotating the substrate
W1 held by the substrate holding unit 52 at a preset speed by
controlling the driving unit 524, the controller 3 controls the
cleaning liquid supply unit 55b to locate the nozzle 551b at a
position above the substrate W1, and a cleaning liquid N2 is
supplied onto the substrate W1 from the nozzle 551b. The cleaning
liquid N2 supplied onto the substrate W1 is diffused on a surface
of the substrate W1 by a centrifugal force which is generated as
the substrate W1 is rotated. As a result, a deposit or the like
adhering to the substrate W1 is removed from the substrate W1. The
cleaning liquid N2 scattered from the substrate W1 is drained
through the drain opening 571c of the cup 57 and the liquid
draining mechanism 59c. When starting this cleaning process, the
controller 3 controls the elevating mechanism 58 to adjust the
position of the cup 57 such that the drain opening 571c of the cup
57 is located at a position where it faces a peripheral edge
portion of the substrate W1.
[0110] In the first rinse process, the substrate W1 after being
cleaned is rinsed. While rotating the substrate W1 held by the
substrate holding unit 52 at a preset speed by controlling the
driving unit 524, the controller 3 controls the rinse liquid supply
unit 55c to locate the nozzle 551c at a position above the
substrate W1, and a rinse liquid N3 is supplied onto the substrate
W1 from the nozzle 551c. The rinse liquid N3 supplied onto the
substrate W1 is diffused on the surface of the substrate W1 by a
centrifugal force which is generated as the substrate W1 is
rotated. As a result, the cleaning liquid N2 remaining on the
substrate W1 is washed away. The rinse liquid N3 scattered from the
substrate W1 is drained through the drain opening 571c of the cup
57 and the liquid draining mechanism 59c. When starting this first
rinse process, the controller 3 controls the elevating mechanism 58
to adjust the position of the cup 57 such that the drain opening
571c of the cup 57 is located at a position where it faces the
peripheral edge portion of the substrate W1.
[0111] In the catalyst solution supplying process, a metal film
(catalyst layer) having catalytic activity is formed on the
substrate W1 after being rinsed. While rotating the substrate W1
held by the substrate holding unit 52 at a preset speed by
controlling the driving unit 524, the controller 3 controls the
catalyst solution supply unit 55a to locate the nozzle 551a at a
position above the substrate W1, and a catalyst solution N1 is
supplied onto the substrate W1 from the nozzle 551a. The catalyst
solution N1 supplied onto the substrate W1 is diffused on the
surface of the substrate W1 by a centrifugal force which is
generated as the substrate W1 is rotated. As a result, a metal film
(e.g., a Pd film) having catalytic activity is formed on a plating
target surface (e.g., a copper wiring formed on the surface of the
substrate W1). The catalyst solution N1 scattered from the
substrate W1 is drained through the drain opening 571b of the cup
57 and the liquid draining mechanism 59b. When starting this
catalyst solution supplying process, the controller 3 controls the
elevating mechanism 58 to adjust the position of the cup 57 such
that the drain opening 571b of the cup 57 is located at a position
where it faces the peripheral edge portion of the substrate W1.
[0112] In the second rinse process, the substrate W1 on which the
catalyst layer is formed is rinsed. While rotating the substrate W1
held by the substrate holding unit 52 at a preset speed by
controlling the driving unit 524, the controller 3 controls the
rinse liquid supply unit 55c to locate the nozzle 551c at a
position above the substrate W1, and the rinse liquid N3 is
supplied onto the substrate W1 from the nozzle 551c. The rinse
liquid N3 supplied onto the substrate W1 is diffused on the surface
of the substrate W1 by a centrifugal force which is generated as
the substrate W1 is rotated. As a result, the catalyst solution N1
remaining on the substrate W1 is washed away. The rinse liquid N3
scattered from the substrate W1 is drained through the drain
opening 571c of the cup 57 and the liquid draining mechanism 59c.
When starting this second rinse process, the controller 3 controls
the elevating mechanism 58 to adjust the position of the cup 57
such that the drain opening 571c of the cup 57 is located at the
position where it faces the peripheral edge portion of the
substrate W1
[0113] After the above-described pretreatment process is performed,
if necessary, the plating process is performed. In the plating
process, while rotating the substrate W1 held by the substrate
holding unit 52 at a low speed (a speed at which the plating liquid
M1 supplied onto the substrate W1 is not scattered from the
substrate W1) by controlling the driving unit 524 or while
maintaining the substrate W1 held by the substrate holding unit 52
not to be rotated, the controller 3 controls the plating liquid
supply unit 53 to locate the nozzle 531 at a position above the
substrate W1, and the plating liquid M1 is supplied onto the
substrate W1 from the nozzle 531. After a preset amount of the
plating liquid M1 is once supplied onto the substrate W1 from the
nozzle 531, the controller 3 controls the plating liquid supply
unit 53 not to supply new plating liquid M1 until the plating with
the supplied plating liquid M1 is finished.
[0114] The temperature of the plating liquid M1 supplied from the
plating liquid supply unit 53 is lower than the preset plating
temperature. Thus, at a time point when the plating liquid M1 is
supplied onto the substrate W1 held by the substrate holding unit
52 from the plating liquid supply unit 53, the plating liquid M1
does not exert the preset plating performance, and the plating
reaction is not begun, or, even if begun, it progresses very
slowly.
[0115] After the plating liquid M1 is supplied onto the substrate
W1 held by the substrate holding unit 52, the controller 3 controls
the elevating mechanism 62 to move the top plate 61 horizontally up
to the position where the top plate 61 covers the substantially
entire surface region of the substrate W1 and, then, to move the
top plate 61 down, so that the top plate 61 is located close to the
substrate W1. Accordingly, when the plating liquid M1 supplied onto
the substrate W1 is heated by the plating liquid heating unit 63,
there is formed the space S between the substrate W1 held by the
substrate holding unit 52 and the top plate 61. The space S is
surrounded by the cup 57. The space S is not sealed by the cup 57
and communicates with the external space. After the top plate 61 is
placed close to the substrate W1, the controller 3 controls the
plating liquid heating unit 63 to heat the plating liquid M1 on the
substrate W1 to the preset plating temperature. The controller 3
may control the plating liquid heating unit 63 to heat the
substrate W1 before the plating liquid M1 is supplied. In such a
case, the controller 3 controls the elevating mechanism 62 to move
the top plate 61 horizontally up to the position where it covers
the substantially entire surface region of the substrate W1 and,
then, to move the top plate 61 down, so that the top plate 61 is
located near the substrate W1. Then, by controlling the plating
liquid heating unit 63, preliminary heating on the substrate W1 is
performed.
[0116] After the plating liquid M1 is supplied from the plating
liquid supply unit 53 onto the substrate W1 held by the substrate
holing unit 52, at a time point when the temperature of the plating
liquid M1 has reached the preset plating temperature while being
heated by the plating liquid heating unit 63, the plating liquid M1
exerts the preset plating performance, so that the plating is
begun. During the plating, the controller 3 controls the plating
liquid heating unit 63 to allow the temperature of the plating
liquid M1 to be maintained at the preset plating temperature.
Accordingly, a plating film is formed on the plating target surface
of the substrate W1 (on the metal film (e.g., the Pd film), which
has catalytic activity and is formed on the surface of the
substrate W1, in case that the catalyst solution supplying process
is performed).
[0117] Through the above processes, the plating on the single sheet
of substrate W1 is performed with the plating liquid M1 heated to
the preset plating temperature. That is, the controller 3 controls
the plating liquid supply unit 53 and the plating liquid heating
unit 63 such that, after the preset amount of the plating liquid M1
is supplied to the substrate W1 held by the substrate holding unit
52 one time, the supplied plating liquid M1 is heated to the preset
plating temperature by the plating liquid heating unit 63, and the
plating is performed with the plating liquid M1 heated to the
preset plating temperature.
[0118] After the plating liquid M1 is supplied from the plating
liquid supply unit 53 onto the substrate W1 held by the substrate
holding unit 52, the supplied plating liquid M1 is heated by the
plating liquid heating unit 63. As a result, the moisture in the
plating liquid M1 is evaporated, and the vapor generated from the
plating liquid M1 stays in the space S. The space S is surrounded
by the cup 57, but is not sealed by the cup 57 and communicates
with the external space (space within the chamber 51). The vapor
generated from the plating liquid M1 is flown into the external
space after staying in the space S. Accordingly, the moisture in
the plating liquid M1 is continuously evaporated. The evaporation
amount of the moisture from the plating liquid M1 can be adjusted
by controlling the volume of the space S (for example, the distance
between the top plate 61 and the substrate W1 held by the substrate
holding unit 52). For instance, by reducing the volume of the space
S, the evaporation amount of the moisture from the plating liquid
M1 can be reduced, and, thus, the sharp increase of the
concentration of the plating liquid M1 caused by the evaporation of
the moisture can be suppressed. The distance between the top plate
61 and the substrate W1 held by the substrate holding unit 52 may
be appropriately controlled based on the set temperature of the top
plate, the temperature of the plating liquid after being heated,
the temperature rising rate of the plating liquid, the amount of
the plating liquid on the substrate, and so forth.
[0119] As the plating liquid M1 is heated by the plating liquid
heating unit 63 after being supplied from the plating liquid supply
unit 53 onto the substrate W1 held by the substrate holding unit
52, the temperature of the plating liquid M1 is increased, and the
moisture in the plating liquid M1 is evaporated, so that the
concentration of the plating liquid M1 is increased. As a result,
the concentration of the plating liquid M1 at a time when the
temperature of the plating liquid M1 has reached the preset plating
temperature becomes equal to or higher than the lower limit (i.e.,
C.sub.L(%)) of the preset concentration range or equal to or lower
than the median value (i.e., (C.sub.L+C.sub.H)/2) of the preset
concentration range.
[0120] The plating component of the plating liquid M1 is consumed
after the temperature of the plating liquid M1 reaches the preset
plating temperature. Since, however, the heating by the plating
liquid heating unit 63 is continued, the concentration of the
plating liquid M1 is increased. That is, since the increase of the
concentration of the plating liquid M1 caused by the evaporation of
the moisture from the plating liquid M1 is more dominant than the
decrease of the concentration of the plating liquid M1 caused by
the consumption of the plating component within the plating liquid
M1, the concentration of the plating liquid M1 is increased even
after the plating liquid M1 reaches the preset plating temperature,
and reaches the upper limit (i.e., C.sub.H (%)) of the preset
concentration range, shortly.
[0121] As the concentration of the plating liquid M1 at the time
when the temperature of the plating liquid M1 has reached the
preset plating temperature is closer to the lower limit (i.e.,
C.sub.L (%)) of the preset concentration range, a time period taken
until the concentration of the plating liquid M1 reaches the upper
limit (i.e., C.sub.H (%)) of the preset concentration range, that
is, a time period during which the plating liquid M1 is used for
the plating is lengthened.
[0122] The controller 3 finishes the plating by draining the
plating liquid M1 from the substrate W1 before the concentration of
the plating liquid M1 reaches the upper limit (i.e., C.sub.H (%))
of the preset concentration range. When finishing the plating, the
controller 3 controls the elevating mechanism 62 to move the top
plate 61 up to a preset position and to move the top plate 61
horizontally up to the position where the top plate 61 does not
cover the substantially entire surface region of the substrate W1.
Thereafter, while rotating the substrate W1 held by the substrate
holding unit 52 at a preset speed by controlling the driving unit
524, the controller 3 controls the rinse liquid supply unit 55c to
locate the nozzle 551c at a position above the substrate W1, and
the rinse liquid N3 is supplied onto the substrate W1 from the
nozzle 551c. The plating liquid M1 and the rinse liquid N3 on the
substrate W1 are scattered from the substrate W1 by a centrifugal
force which is generated as the substrate W1 is rotated, and the
plating liquid M1 and the rinse liquid N3 scattered from the
substrate W1 are drained through the drain opening 571a of the cup
57 and the liquid draining mechanism 59a. When finishing the
plating, the controller 3 controls the elevating mechanism 58 to
adjust the position of the cup 57 such that the drain opening 571a
of the cup 57 is located at the position where it faces the
peripheral edge portion of the substrate W1.
[0123] In the plating device 5, it is desirable to perform a drying
process of drying the substrate W1 after the plating process. In
the drying process, the substrate W1 can be dried naturally by
rotating the substrate W1, or by discharging a drying solvent or a
drying gas to the substrate W1.
[0124] After the plating process, a substrate carry-out process is
performed. In the substrate carry-out process, the substrate W2 on
which the plating is completed is carried out from the plating
device 5. At this time, the controller 3 controls the transfer
device 222 to take out the substrate W2 from the plating device 5
and place the taken substrate W2 in the delivery unit 214. Then,
the controller 3 controls the transfer device 213 to take out the
substrate W2 from the delivery unit 214 and accommodate the
substrate W2 in the carrier C in the placing section 211.
[0125] 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.
* * * * *