U.S. patent application number 16/081687 was filed with the patent office on 2021-02-11 for plating apparatus and plating method.
This patent application is currently assigned to Ebara Corporation. The applicant listed for this patent is EBARA CORPORATION. Invention is credited to Takashi KISHI, Mizuki NAGAI, Fumitoshi NISHIURA, Masashi SHIMOYAMA.
Application Number | 20210040641 16/081687 |
Document ID | / |
Family ID | 1000005223359 |
Filed Date | 2021-02-11 |
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United States Patent
Application |
20210040641 |
Kind Code |
A1 |
NAGAI; Mizuki ; et
al. |
February 11, 2021 |
PLATING APPARATUS AND PLATING METHOD
Abstract
Provided is a plating apparatus for plating a substrate, which
prevents deterioration of uniformity of plating film thickness
caused by an oxide film created at an edge section of the substrate
and/or an organic substance attached to the edge section of the
substrate. The plating apparatus includes a plating bath for
applying a voltage to the substrate set in a substrate holder to
plate the substrate; and an edge section washing device that
locally removes at least either of the organic substance and the
oxide film present at the edge section of the substrate before the
substrate is set in the substrate holder.
Inventors: |
NAGAI; Mizuki; (Tokyo,
JP) ; SHIMOYAMA; Masashi; (Tokyo, JP) ; KISHI;
Takashi; (Tokyo, JP) ; NISHIURA; Fumitoshi;
(Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EBARA CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
Ebara Corporation
Tokyo
JP
|
Family ID: |
1000005223359 |
Appl. No.: |
16/081687 |
Filed: |
March 2, 2017 |
PCT Filed: |
March 2, 2017 |
PCT NO: |
PCT/JP2017/008256 |
371 Date: |
August 31, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C25D 7/123 20130101;
C25D 17/001 20130101; C25D 5/34 20130101; C25D 17/06 20130101 |
International
Class: |
C25D 17/06 20060101
C25D017/06; C25D 7/12 20060101 C25D007/12; C25D 5/34 20060101
C25D005/34; C25D 17/00 20060101 C25D017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 4, 2016 |
JP |
2016-042145 |
Feb 21, 2017 |
JP |
2017-029890 |
Claims
1. A plating apparatus for plating a substrate, the plating
apparatus comprising: an edge section washing device configured to
locally remove at least either of an organic substance and an oxide
film existing at an edge section of the substrate; and a plating
bath configured to contain a plating solution such that a voltage
is applied between the substrate and an anode for plating while the
substrate and the anode are immersed in the plating solution.
2. The plating apparatus according to claim 1, wherein the edge
section washing device includes an organic substance desorption
device configured to locally desorb the organic substance existing
at the edge section of the substrate, and the organic substance
desorption device comprising a UV irradiation device configured to
irradiate the edge section of the substrate that is rotating with
an ultraviolet or a plasma emission device configured to emit a
plasma to the edge section of the rotating substrate.
3. The plating apparatus according to claim 2, further comprising
an aligner configured to rotate the substrate to align the
orientation of the substrate, wherein the organic substance
desorption device is provided at the aligner.
4. The plating apparatus according to claim 2, wherein the UV
irradiation device or the plasma emission device is arranged at a
position where the UV or plasma can be locally applied to the edge
section of the substrate from above the substrate.
5. The plating apparatus according to claim 1, wherein the edge
section washing device includes an oxide film removal device
configured to locally remove an oxide film existing at the edge
section of the substrate, and the oxide film removal device
includes a chemical liquid washing device including a chemical
liquid nozzle for supplying a chemical liquid to the edge section
of the substrate that is rotating.
6. The plating apparatus according to claim 5, wherein the chemical
liquid contains 3 wt % or more and 15 wt % or less of diluted
sulfuric acid or 2 wt % or more and 20 wt % or less of citric
acid.
7. The plating apparatus according to claim 5, further comprising a
spin rinse dryer configured to rotate and dry the substrate, and
the oxide film removal device is provided at the spin rinse
dryer.
8. The plating apparatus according to claim 5, wherein the chemical
liquid washing device is arranged at a position where the chemical
liquid washing device is allowed to locally supply the chemical
liquid to the edge section of the substrate from above the
substrate.
9. The plating apparatus according to claim 1, further comprising a
sponge washing device configured to remove a particle existing at
the edge section of the substrate.
10. The plating apparatus according to claim 1, further comprising
a sensor configured to irradiate with a light the edge section of
the substrate from which at least either of the organic substance
and the oxide film existing at the edge section has been locally
removed and measure an intensity or absorbance of a reflected
light.
11. A plating method for plating a substrate, the plating method
comprising: a removal step of locally removing at least either of
an organic substance and an oxide film existing at an edge section
of the substrate; a step of holding the substrate by a substrate
holder; and a step of performing a plating process on the substrate
held by the substrate holder.
12. The plating method according to claim 11, further comprising: a
step of forming a resist pattern on the substrate; and an ashing
step of ashing the resist pattern, wherein the removal step is
performed after the ashing step.
13. The plating method according to claim 11, wherein the removal
step includes a step of locally radiating an ultraviolet or plasma
to the edge section of the substrate.
14. The plating method according to claim 11, wherein the removal
step includes a step of locally supplying a chemical liquid to the
edge section of the substrate.
15. The plating method according to claim 14, wherein the chemical
liquid contains 3 wt % or more and 15 wt % or less of diluted
sulfuric acid or 2 wt % or more and 20 wt % or less of citric
acid.
16. The plating method according to claim 11, further comprising a
step of bringing a sponge head into contact with the edge section
of the substrate that is rotating to remove a particle.
17. The plating method according to claim 11, wherein the removal
step includes a step of locally removing the oxide film after
locally desorbing the organic substance existing at the edge
section of the substrate.
18. The plating method according to claim 11, wherein the removal
step includes a step of locally removing at least either of the
organic substance and the oxide film existing within a range of 2
millimeters from a peripheral portion of the substrate toward the
center of the substrate.
19. The plating method according to claim 11, wherein the removal
step includes a step of locally removing at least either of the
organic substance and the oxide film existing in a region reaching
a peripheral portion of the substrate adjacent to a region sealed
by a seal member when the substrate is held by the substrate
holder.
20. The plating method according to claim 11, further comprising a
step of irradiating with a light the edge section of the substrate
from which at least either of the organic substance and the oxide
film existing in the edge section has been removed and measuring an
intensity or absorbance of a reflected light.
21. A plating apparatus for plating a substrate, the plating
apparatus comprising: a plating bath for performing plating by
applying a voltage to the substrate held by a substrate holder; and
an edge section washing device configured to locally remove at
least any one of an organic substance, an oxide film, and a
particle existing at an edge section of the substrate.
22. A plating method for plating a substrate, the plating method
comprising: a removal step of locally removing at least any one of
an organic substance, an oxide film, and a particle existing at an
edge section of the substrate before the substrate is set in a
substrate holder; a step of holding the substrate by the substrate
holder; and a step of performing a plating process on the substrate
held by the substrate holder.
23. The plating apparatus according to claim 1, wherein the edge
section washing device includes an organic substance desorption
device configured to locally desorb the organic substance existing
at the edge section of the substrate, the organic substance
desorption device including a UV irradiation device configured to
irradiating the edge section of the substrate with an ultraviolet
or a plasma emission device configured to emit a plasma to the edge
section of the substrate.
24. The plating apparatus according to claim 23, wherein the edge
section washing device includes a head unit configured to locally
apply the ultraviolet or plasma to the edge section of the
substrate, and an actuator configured to move the head unit in a
horizontal direction.
25. The plating apparatus according to claim 24, wherein the
actuator comprises a first actuator configured to move the head
unit in a first direction and a second actuator configured to move
the head unit in a second direction orthogonal to the first
direction.
26. The plating apparatus according to claim 24, wherein the edge
section washing device has a control unit configured to control the
head unit and the actuator, the actuator is configured to move the
head unit along the edge section of the substrate, and the control
unit controls the head unit and the actuator such that the
irradiation with the ultraviolet or plasma by the head unit and the
movement of the head unit along the edge section of the substrate
by the actuator take place simultaneously.
27. The plating apparatus according to claim 26, wherein the edge
section washing device has a pivot mechanism configured to cause
the head unit to pivot, and the control unit controls the head unit
and the pivot mechanism such that irradiation with the ultraviolet
or plasma by the head unit is stopped while the head unit is made
to pivot by the pivot mechanism.
28. The plating apparatus according to claim 26, wherein the edge
section washing device has a rotation mechanism configured to
rotate the substrate, and a control unit configured to control the
head unit, the rotation mechanism, and the actuator, and the
control unit controls the head unit and the rotation mechanism such
that irradiation with the ultraviolet or plasma by the head unit is
stopped while the substrate is rotated by the rotation
mechanism.
29. The plating method according to claim 11, wherein the removal
step includes a step of radiating an UV or plasma while moving a
head unit radiating the UV or plasma along the edge section of the
rectangular substrate.
30. The plating method according to claim 29, wherein the removal
step includes a step of moving the head unit in a horizontal
direction to adjust a position of the head unit to the edge section
of the rectangular substrate.
31. The plating method according to claim 29, wherein the removal
step has a step of causing the head unit to pivot while radiation
of the ultraviolet or plasma is stopped after the ultraviolet or
plasma has been radiated to one of the edge sections of the
rectangular substrate.
32. The plating method according to claim 29, wherein the removal
step has a step of rotating the rectangular substrate while
radiation of the ultraviolet or plasma is stopped after the UV or
plasma has been radiated to one of the edge sections of the
rectangular substrate.
Description
TECHNICAL FIELD
[0001] The present invention relates to a plating apparatus and a
plating method.
BACKGROUND ART
[0002] Traditionally, wiring is formed in a fine wiring grooves,
holes, or resist openings provided on a surface of a semiconductor
wafer or the like, or a bump (an electrode having a shape of a
projection) electrically connected to an electrode or the like of a
package is formed on the surface of a semiconductor wafer or the
like. For example, electrolytic plating method, vapor deposition
method, printing method, ball bump method, etc. are known as a
method of forming such wirings and bumps. As the number of I/Os of
semiconductor chips increases and the pitch becomes finer,
electrolytic plating methods that realize miniaturization and have
relatively stable performance have been increasingly used.
[0003] In order to perform plating on a substrate by an
electrolytic plating method, a resist pattern is formed, prior to
the plating, on a substrate such as a semiconductor wafer on which
a seed layer is formed. Subsequently, the substrate on which the
resist pattern has been formed is irradiated with ultraviolet light
(hereinafter referred to as UV or ultraviolet) to remove resist
residues on the substrate surface (ashing treatment) and
hydrophilization treatment (descum treatment) is performed on the
resist surface.
[0004] The substrate that has been subjected to the ashing and
descum treatments is conveyed to a plating device and held by a
substrate holder. The substrate holder has an electrical contact
for providing electricity to the substrate. The electrical contact
of the substrate holder is configured to be brought into contact
with the seed layer at the edge section of the substrate that is
not coated with a resist when the substrate is held by the
substrate holder. Such a substrate holder is disclosed, for
example, in Patent Document 1. The substrate held by the substrate
holder is immersed in a plating solution, and a voltage is applied
between an anode and the substrate, so that a plating film is
formed on the substrate surface.
CITATION LIST
Patent Literature
[0005] PTL1: Japanese Patent Application Laid-Open No.
2002-363794
SUMMARY OF INVENTION
Technical Problem
[0006] According to the traditional plating method, a plating
process is not performed immediately after ashing and descum
treatments are performed. Specifically, the substrate is held by
the substrate holder after a predetermined time has elapsed after
the ashing and descum treatments. At this point, an oxidation film
may be created on the seed layer on the edge section of the
substrate or an organic substance or substances volatilized from
the resist may adhere thereto due to passage of time from the
ashing and descum treatments. When an oxide film is created on the
seed layer on the edge section of the substrate to be brought into
contact with the electrical contact of the substrate or organic
substances adhere thereto, the contact resistance of the electrical
contact of the substrate holder varies, which may problematically
deteriorate uniformity of the plating film thickness.
[0007] The present invention has been made in view of the
above-identified problem, and one of the objects of the present
invention is to prevent deterioration of the uniformity of the
plating film thickness caused by at least either of an oxide film
created on an edge section of a substrate and organic substances
attached to the edge section of the substrate.
Solution to Problem
[0008] According to an embodiment of the present invention, there
is provided a plating apparatus for plating a substrate. The
plating apparatus includes an edge section washing device
configured to locally remove at least either of an organic
substance and an oxide film present at an edge section of the
substrate, and a plating bath configured to contain a plating
solution such that the substrate and an anode are immersed in the
plating solution for performing plating in this state with a
voltage applied between the substrate and the anode.
[0009] According to this embodiment, at least either of the organic
substance and the oxide film existing at the edge section of the
substrate can be locally removed before the substrate is set in the
substrate holder. Accordingly, it is made possible to suppress
variation in the contact resistance of the electrical contact of
the substrate holder due to at least either of the organic
substance and the oxide film present at the edge section of the
substrate without adversely affecting the resist pattern formed on
the surface other than the edge section of the substrate and
prevent deterioration of the uniformity of the plating film
thickness.
[0010] In one embodiment of the present invention, the edge section
washing device includes an organic substance desorption device
configured to locally desorb the organic substances present at the
edge section of the substrate, wherein the organic substance
desorption device includes a UV irradiation device configured to
irradiate the edge section of the rotating substrate with an
ultraviolet or a plasma emission device configured to emit a plasma
to the edge section of the rotating substrate.
[0011] In general, a resist is coated on a substrate to be plated,
and when such a resist is irradiated with a UV or plasma, the
resist may be denatured and damaged. According to this embodiment,
it is made possible to locally emit UV or plasma to the edge
section of the substrate. By virtue of this, the UV or plasma is
not emitted to the surface other than the edge section of the
substrate, i.e., the portion on the substrate where the resist is
applied, so that the resist on the substrate is not damaged and the
organic substances at the edge section can be desorbed.
[0012] In one embodiment of the present invention, the plating
apparatus has an aligner configured to rotate the substrate to
align the orientation of the substrate, and the organic substance
desorption device is provided at the aligner.
[0013] According to this embodiment, since the organic substance
desorption device is provided at the aligner, it is possible to
process the edge section of the substrate with the UV irradiation
device or the plasma emission device while rotating the substrate
with the aligner. Accordingly, since it is not necessary to provide
a mechanism for rotating the substrate in the organic substance
desorption device, the cost can be reduced. Also, by providing the
organic substance desorption device at the aligner, it is made
possible to reduce the footprint of the plating apparatus as a
whole.
[0014] In one embodiment of the present invention, the UV
irradiation device or the plasma emission device is arranged at a
position where a UV or plasma can be locally applied to the edge
section of the substrate from above the substrate.
[0015] In one embodiment of the present invention, the edge section
washing device includes an oxide film removal device for locally
removing an oxide film present at the edge section of the
substrate, and the oxide film removal device includes a chemical
liquid washing device including a chemical liquid nozzle for
supplying a chemical liquid to the edge section of the rotating
substrate.
[0016] In general, a seed layer is formed on a substrate to be
plated, and the seed layer may be melted if the seed layer is left
unattended with the chemical liquid attached thereto. Accordingly,
when a chemical liquid adheres to a portion other than the edge
section of the substrate to be plated, i.e., the seed layer exposed
via the opening of the resist pattern, sufficient washing is
required so that no chemical liquid remains. According to this
embodiment, it is made possible to supply the chemical liquid
locally to the edge section of the substrate. As a result, the
oxide film created at the edge section of the substrate can be
removed without the chemical liquid adhering to the seed layer
exposed via the opening of the resist pattern. Accordingly, the
washing time for washing the substrate can be greatly shortened as
compared with the case where the chemical liquid adheres to the
entire surface of the substrate.
[0017] In one embodiment of the present invention, the chemical
liquid contains 3 wt % or more and 15 wt % or less of diluted
sulfuric acid or 2 wt % or more and 20 wt % or less of citric
acid.
[0018] It is necessary to prevent the seed layer on the edge
section of the substrate from being melted when removing the oxide
film at the edge section of the substrate using the chemical
liquid. According to this embodiment, it is made possible to remove
the oxide film without causing melting of the seed layer on the
edge section of the substrate. If the diluted sulfuric acid is less
than 3 wt % or citric acid is less than 2 wt %, there is a
possibility that the acid concentration may be too low to properly
remove the oxide film. Also, if the diluted sulfuric acid exceeds
15 wt % or citric acid exceeds 20 wt %, the acid concentration is
too high and there is a possibility that the seed layer on the edge
section of the substrate is melted.
[0019] In one embodiment of the present invention, the plating
apparatus includes a spin rinse dryer configured to rotate and dry
the substrate, and the oxide film removal device is provided at the
spin rinse dryer.
[0020] According to this embodiment, since the oxide film removal
device is provided at the spin rinse dryer, it is made possible to
process the edge section of the substrate with the chemical liquid
washing device while rotating the substrate with the spin rinse
dryer. In addition, since the spin rinse dryer generally has a
cover for preventing the liquid on the substrate from scattering,
scattering of the chemical liquid supplied from the chemical liquid
washing device to the outside of the spin rinse dryer is also
prevented. Accordingly, it is not necessary to provide a mechanism
for rotating the substrate in the oxide film removal device and a
cover for preventing scattering of the chemical liquid, so that the
cost can be reduced. Further, by providing the oxide film removal
device in the spin rinse dryer, it is made possible to reduce the
footprint of the plating apparatus as a whole.
[0021] In one embodiment of the present invention, the chemical
liquid washing device is arranged at a position where chemical
liquid washing device is allowed to locally supply the chemical
liquid to the edge section of the substrate from above the
substrate.
[0022] In one embodiment of the present invention, the plating
apparatus has a sponge washing device configured to remove
particles present at the edge section of the substrate.
[0023] According to this embodiment, it is made possible to prevent
particles from being caught between the electrical contact of the
substrate holder and the seed layer on the edge section of the
substrate, and it is made possible to suppress deterioration of
contact resistance due to particles.
[0024] In one embodiment of the present invention, the plating
apparatus irradiates with light the edge section of the substrate
from which at least either of the organic substance and the oxide
film present at the edge section has been locally removed, and
includes a sensor configured to measure an intensity or absorbance
of a reflected light.
[0025] According to this embodiment, by measuring the intensity or
absorbance of the reflected light, for the substrate from which at
least either of the organic substance and the oxide film existing
at the edge section has been locally removed, it is made possible
to determine whether or not contaminants at the edge section of the
substance have been sufficiently removed. By virtue of this, it is
made possible to determine whether or not contaminants are present
at the edge section of the substrate before the plating process,
and thereafter the plating process can be performed on the
substrate on which no contaminants remain at the edge section, so
that it is made possible to more reliably prevent deterioration or
the like of in-plane uniformity of the plating film thickness of
the substrate W due to variations in the contact resistance of the
electrical contact of the substrate holder.
[0026] According to one embodiment of the present invention, there
is provided a plating method for plating a substrate. The plating
method includes a removal step of locally removing at least either
of organic substances and an oxide film present at an edge section
of the substrate, a step of holding the substrate by a substrate
holder, and a step of performing a plating process on the substrate
held by the substrate holder.
[0027] According to this embodiment, at least either of the organic
substances and the oxide film existing at the edge section of the
substrate can be locally removed before the substrate is set in the
substrate holder. Accordingly, it is made possible to suppress
variation in the contact resistance of the electrical contact of
the substrate holder due to at least either of the organic
substance and the oxide film present at the edge section of the
substrate without adversely affecting the resist pattern formed on
the surface other than the edge section of the substrate and
prevent deterioration of the uniformity of the plating film
thickness.
[0028] In one embodiment of the present invention, the plating
method includes a step of forming a resist pattern on the substrate
and an ashing step of ashing the resist pattern, and the removal
step is performed after the ashing step.
[0029] According to this embodiment, since the removal step is
performed after the ashing step. Even when at least either of
adhesion of organic substance to the edge section of the substrate
and creation of the oxide film thereon occurs after a predetermined
time has elapsed following the ashing step, at least either of the
organic substance and the oxide film existing at the edge section
of the substrate can be locally removed by the removal step.
[0030] In one embodiment of the present invention, the removal step
includes a step of locally emitting a UV or plasma to the edge
section of the substrate.
[0031] In general, a resist is coated on a substrate to be plated,
and when such a resist is irradiated with a UV or plasma, the
resist may be denatured and damaged. According to this embodiment,
it is made possible to locally emit UV or plasma to the edge
section of the substrate. By virtue of this, the UV or plasma is
not emitted to the surface other than the edge section of the
substrate, i.e., the portion on the substrate where the resist is
applied, so that the resist on the substrate is not damaged and the
organic substance at the edge section can be desorbed.
[0032] In one embodiment of the present invention, the removal step
includes a step of locally supplying a chemical liquid to the edge
section of the substrate.
[0033] In general, a seed layer is formed on a substrate to be
plated, and the seed layer may be melted if the seed layer is left
unattended with the chemical liquid attached thereto. Accordingly,
when a chemical liquid adheres to a portion other than the edge
section of the substrate to be plated, i.e., the seed layer exposed
via the opening of the resist pattern, sufficient washing is
required so that no chemical liquid remains. According to this
embodiment, it is made possible to supply the chemical liquid
locally to the edge section of the substrate. As a result, the
oxide film created at the edge section of the substrate can be
removed without the chemical liquid adhering to the seed layer
exposed via the opening of the resist pattern. Accordingly, the
washing time for washing the substrate can be greatly shortened as
compared with the case where the chemical liquid adheres to the
entire surface of the substrate.
[0034] In one embodiment of the present invention, the chemical
liquid contains 3 wt % or more and 15 wt % or less of diluted
sulfuric acid or 2 wt % or more and 20 wt % or less of citric
acid.
[0035] It is necessary to prevent the seed layer on the edge
section of the substrate from being melted when removing the oxide
film at the edge section of the substrate using the chemical
liquid. According to this embodiment, it is made possible to remove
the oxide film without causing melting of the seed layer on the
edge section of the substrate. If the dilute sulfuric acid is less
than 3 wt % or citric acid is less than 2 wt %, there is a
possibility that the acid concentration may be too low to properly
remove the oxide film. Also, if the diluted sulfuric acid exceeds
15 wt % or citric acid exceeds 20 wt %, the acid concentration is
too high and there is a possibility that the seed layer on the edge
section of the substrate is melted.
[0036] In one embodiment of the present invention, the plating
method has a step of removing particles by bringing a sponge head
into contact with the edge section of the rotating substrate.
[0037] According to this embodiment, it is made possible to prevent
particles from being caught between the electrical contact of the
substrate holder and the seed layer on the edge section of the
substrate, and it is made possible to suppress deterioration of
contact resistance due to particles.
[0038] In one embodiment of the present invention, the removal step
includes a step of locally removing the oxide film after having
locally desorbed the organic substance present at the edge section
of the substrate.
[0039] At the edge section of the substrate, organic substance may
adhere to the oxide film. Accordingly, when the oxide film is
removed before the organic substance is desorbed, it is difficult
to remove the oxide film at the portion where the organic
substances adhere. According to this embodiment, since the oxide
film is removed after having desorbed the organic substance, it is
made possible to effectively remove the organic substance and the
oxide film.
[0040] In one embodiment of the present invention, the removal step
includes a step of locally removing at least either of the organic
substance and the oxide film existing within a range of two
millimeters from the peripheral portion of the substrate toward the
center of the substrate.
[0041] In general, the electrical contact of the substrate holder
is in contact with the edge section in the range of 2 mm from the
peripheral portion of the substrate. Accordingly, according to this
embodiment, it is made possible to locally remove at least either
of the organic substance and the oxide film present at the portion
on the substrate with which the electrical contact of the substrate
holder is in contact.
[0042] In one embodiment of the present invention, the removal step
includes a step of locally removing at least either of the organic
substance and the oxide film existing in a region reaching a
peripheral portion of the substrate adjacent to a region sealed by
a seal member when the substrate is held by the substrate
holder.
[0043] In one embodiment of the present invention, the plating
method has a step of irradiating with a light the edge section of
the substrate from which at least either of the organic substance
and the oxide film present in the edge section has been removed and
measuring an intensity or absorbance of a reflected light.
[0044] According to this embodiment, by measuring the intensity or
absorbance of the reflected light, for the substrate from which at
least either of the organic substance and the oxide film existing
at the edge section has been locally removed, it is made possible
to determine whether or not contaminants at the edge section have
been sufficiently removed. By virtue of this, it is made possible
to determine whether or not contaminants are present at the edge
section of the substrate before the plating process, and thereafter
the plating process can be performed on the substrate on which no
contaminants remain at the edge section, so that it is made
possible to more reliably prevent deterioration or the like of
in-plane uniformity of the plating film thickness of the substrate
W due to variations in the contact resistance of the electrical
contacts of the substrate holder.
[0045] According to one embodiment of the present invention, there
is provided a plating apparatus for plating a substrate. The
plating apparatus includes a plating bath for performing plating by
applying a voltage to the substrate held by a substrate holder; and
an edge section washing device configured to locally remove at
least one of organic substances, an oxide film, and particles
existing at an edge section of the substrate.
[0046] According to this embodiment, it is made possible to locally
remove at least any one of the organic substance, the oxide film,
and the particles existing at the edge section of the substrate
before the substrate is set in the substrate holder. Accordingly,
it is made possible to suppress variation in the contact resistance
of the electrical contact of the substrate holder due to at least
any one of the organic substance, the oxide film, and the particles
present at the edge section of the substrate without adversely
affecting the resist pattern formed on the surface other than the
edge section of the substrate and prevent deterioration of the
uniformity of the plating film thickness.
[0047] According to one embodiment of the present invention, there
is provided a plating method for plating a substrate. The plating
method includes a removal step of locally removing at least any one
of an organic substance, an oxide film, and particles existing an
edge section of the substrate before the substrate is set in a
substrate holder, a step of holding the substrate by a substrate
holder, and a step of performing a plating process on the substrate
held by the substrate holder.
[0048] According to this embodiment, it is made possible to locally
remove at least any one of the organic substance, the oxide film,
and the particles existing at the edge section of the substrate
before the substrate is set in the substrate holder. Accordingly,
it is made possible to suppress variation in the contact resistance
of the electrical contact of the substrate holder due to at least
any one of the organic substance, the oxide film, and the particles
present at the edge section of the substrate without adversely
affecting the resist pattern formed on the surface other than the
edge section of the substrate and prevent deterioration of the
uniformity of the plating film thickness.
[0049] According to the plating apparatus in accordance with one
embodiment of the present invention, the edge section washing
device includes an organic substance desorption device configured
to locally desorb the organic substance present at the edge section
of the substrate, wherein the organic substance desorption device
includes a UV irradiation device configured to irradiating the
portion with a ultraviolet or a plasma emission device configured
to emit a plasma to the edge section of the substrate.
[0050] In general, a resist is coated on a substrate to be plated,
and when such a resist is irradiated with a UV or plasma, the
resist may be denatured and damaged. According to this embodiment,
it is made possible to locally emit UV or plasma to the edge
section of the substrate. By virtue of this, the UV or plasma is
not emitted to the surface other than the edge section of the
substrate, i.e., the portion on the substrate where the resist is
applied, so that the resist on the substrate is not damaged and the
organic substance at the edge section can be desorbed.
[0051] According to the plating apparatus in accordance with one
embodiment of the present invention, the edge section washing
device includes a head unit configured to locally apply the UV or
plasma to the edge section of the substrate; and an actuator
configured to horizontally move the head unit.
[0052] According to this embodiment, since the head unit is movable
in the horizontal direction, it is made possible to wash the edge
section by moving the head unit along the edge section, for
example, even for a rectangular substrate.
[0053] According to the plating apparatus of one embodiment of the
present invention, the actuator includes a first actuator
configured to move the head unit in a first direction and a second
actuator configured to move the head unit in a second direction
orthogonal to the first direction.
[0054] According to this embodiment, the head unit can be moved in
the first direction and the second direction. Accordingly, it is
made possible not only to move the head unit along the edge section
but also to adjust the position of the head unit in a direction
perpendicular to the direction in which the edge section extends.
As a result, for example, even when the substrate is a rectangular
substrate having a long side and a short side, it is made possible
to adjust the position of the head unit with respect to both the
edge section of the long side and the edge section of the short
side.
[0055] According to the plating apparatus in accordance with one
embodiment of the present invention, the edge section washing
device has a control unit configured to control the head unit and
the actuator, and the actuator is configured to move the head unit
along the edge section of the substrate. The control unit controls
the head unit and the actuator such that the irradiation with the
UV or plasma by the head unit and the movement of the had unit
along the edge section of the substrate by the actuator take place
simultaneously.
[0056] According to this embodiment, it is made possible to emit
the UV or plasma while moving the head unit along the edge sections
of the rectangular substrate.
[0057] According to the plating apparatus in accordance with one
embodiment of the present invention, the edge section washing
device has a pivot mechanism configured to cause the head unit to
pivot, and the control unit controls the head unit and the pivot
mechanism such that the head unit stops the emission of the UV or
plasma while the head unit is made to pivot by the pivot
mechanism.
[0058] According to this embodiment, since the head unit is allowed
to pivot, it is made possible to easily move the head unit onto the
edge section of the four sides of the rectangular substrate.
Further, since UV or plasma emission by the head unit is not
performed while the head unit is pivoting, it is made possible to
prevent the UV or plasma from being radiated to an unintended area
on the rectangular substrate.
[0059] According to the plating apparatus in accordance with one
embodiment of the present invention, the edge section washing
device has a rotation mechanism configured to rotate the substrate,
and a control unit configured to control the head unit, the
rotation mechanism, and the actuator. The control unit controls the
head unit and the rotation mechanism such that the head unit stops
UV or plasma radiation while the substrate is rotated by the
rotation mechanism.
[0060] According to this embodiment, since the substrate is allowed
to be rotated, it is made possible to easily move the four edge
sections of the rectangular substrate below the head unit. Further,
since UV or plasma emission by the head unit is not performed while
the head unit is rotated, it is made possible to prevent the UV or
plasma from being radiated to an unintended area on the rectangular
substrate.
[0061] According to the plating method in accordance with one
embodiment of the present invention, the removal step includes a
step of radiating an UV or plasma while moving a head unit emitting
the UV or plasma along the edge section of the rectangular
substrate.
[0062] According to this embodiment, it is made possible to emit
the UV or plasma while moving the head unit along the edge sections
of the rectangular substrate.
[0063] According to the plating method in accordance with one
embodiment of the present invention, the removal step includes a
step of horizontally moving the head unit to adjust a position of
the head unit in relation to the edge section of the rectangular
substrate.
[0064] According to this embodiment, even when the substrate is a
rectangular substrate having a long side and a short side, it is
made possible to position the head unit with respect to both the
edge section of the long side and the edge section of the short
side.
[0065] According to the plating method in accordance with one
embodiment of the present invention, the removal step has a step of
causing the head unit to pivot while the emission of the UV or
plasma is stopped after the UV or plasma has been emitted to one of
the edge sections of the rectangular substrate.
[0066] According to this embodiment, since the head unit is allowed
to pivot, it is made possible to easily move the head unit onto the
edge section of the four sides of the rectangular substrate.
Further, since UV or plasma emission by the head unit is not
performed while the head unit is pivoting, it is made possible to
prevent the UV or plasma from being radiated to an unintended area
on the rectangular substrate.
[0067] According to the plating method in accordance with one
embodiment of the present invention, the removal step has a step of
rotating the rectangular substrate while the emission of the UV or
plasma is stopped after the UV or plasma has been emitted to one of
the edge sections of the rectangular substrate.
[0068] According to this embodiment, since the substrate is allowed
to be rotated, it is made possible to easily move the four edge
sections of the rectangular substrate below the head unit. Further,
since UV or plasma emission by the head unit is not performed while
the head unit is rotated, it is made possible to prevent the UV or
plasma from being radiated to an unintended area on the rectangular
substrate.
Advantageous Effects of Invention
[0069] According to the present invention, it is made possible to
prevent deterioration of uniformity of the plating film thickness
due to at least either of the oxide film created on the edge
section of the substrate and the organic substances adhering to the
edge section of the substrate.
BRIEF DESCRIPTION OF DRAWINGS
[0070] FIG. 1 is an overall schematic representation of a plating
apparatus according to a first embodiment.
[0071] FIG. 2 is a perspective view of a substrate holder used in
the plating apparatus illustrated in FIG. 1.
[0072] FIG. 3 is a cross-sectional view illustrating an electrical
contact of the substrate holder illustrated in FIG. 2.
[0073] FIG. 4 is a schematic top view of an aligner illustrated in
FIG. 1.
[0074] FIG. 5 is a schematic cross-sectional view of the aligner
taken along the line 5-5 indicated in FIG. 4.
[0075] FIG. 6 is a schematic cross-sectional view of the aligner
taken along the line 6-6 indicated in FIG. 4.
[0076] FIG. 7 is a flow chart illustrating a plating method
according to the first embodiment.
[0077] FIG. 8 is an overall schematic representation of another
example of the plating apparatus according to the first
embodiment.
[0078] FIG. 9 is an overall schematic representation of a plating
apparatus according to a second embodiment.
[0079] FIG. 10 is a schematic diagram of a spin rinse dryer
including an oxide film removal device.
[0080] FIG. 11 is a flow chart illustrating a plating method
according to the second embodiment.
[0081] FIG. 12 is an overall schematic representation of a plating
apparatus according to a third embodiment.
[0082] FIG. 13 is a flow chart illustrating a plating method
according to the third embodiment.
[0083] FIG. 14 is an overall schematic representation of a plating
apparatus according to a fourth embodiment.
[0084] FIG. 15 is a schematic side view of a sponge washing
device.
[0085] FIG. 16 is a flow chart illustrating a plating method
according to the fourth embodiment.
[0086] FIG. 17 is an overall schematic representation of a plating
apparatus according to a fifth embodiment.
[0087] FIG. 18 is a schematic side view of a sponge chemical liquid
washing device.
[0088] FIG. 19 is a flow chart illustrating a plating method
according to the fifth embodiment.
[0089] FIG. 20 is an overall schematic representation of a plating
apparatus according to a sixth embodiment.
[0090] FIG. 21 is a flow chart illustrating a plating method
according to the sixth embodiment.
[0091] FIG. 22 is a schematic side view of an example of an organic
substance desorption device provided at a fixing unit.
[0092] FIG. 23A is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
an edge section of a rectangular substrate using the organic
substance desorption device illustrated in FIG. 22.
[0093] FIG. 23B is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 22.
[0094] FIG. 23C is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 22.
[0095] FIG. 23D is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 22.
[0096] FIG. 23E is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 22.
[0097] FIG. 24 is a schematic side view of another example of the
organic substance desorption device provided at the fixing
unit.
[0098] FIG. 25A is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 24.
[0099] FIG. 25B is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 24.
[0100] FIG. 25C is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 24.
[0101] FIG. 25D is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 24.
[0102] FIG. 25E is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 24.
[0103] FIG. 26 is a schematic side view of another example of the
organic substance desorption device provided at the fixing
unit.
[0104] FIG. 27A is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 26.
[0105] FIG. 27B is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 26.
[0106] FIG. 27C is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 26.
[0107] FIG. 28 is a schematic side view of another example of the
organic substance desorption device provided at the fixing
unit.
[0108] FIG. 29A is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 28.
[0109] FIG. 29B is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 28.
[0110] FIG. 29C is a plan view of the organic substance desorption
device illustrating a process of desorbing an organic substance at
the edge section of the rectangular substrate using the organic
substance desorption device illustrated in FIG. 28.
DESCRIPTION OF EMBODIMENTS
First Embodiment
[0111] Embodiments of the present invention will be described
hereinbelow with reference to the drawings. In the drawings
described below, the same or corresponding constituent elements are
denoted by the same reference numerals with redundant explanations
thereof omitted.
[0112] FIG. 1 is an overall schematic representation of a plating
apparatus according to a first embodiment. As illustrated in FIG.
1, the plating apparatus is roughly divided into a load/unload unit
170A for loading a substrate in a substrate holder 60 or unloads
the substrate from the substrate holder 60 and a processing unit
170B for processing the substrate.
[0113] The load/unload unit 170A includes three front-opening
unified pods (FOUPs) 102, an aligner 40 configured to adjust a
position of an orientation flat, a notch, and the like of the
substrate in a predetermined direction, and a spin rinse dryer 20
configured to rotate the substrate at a high speed to dry the
substrate. The FOUP 102 is configured to accommodate a plurality of
substrates such as a semiconductor wafer in multiple stages. A
fixing unit 120 is provided near the spin rinse dryer 20. The
fixing unit 120 is configured to place the substrate holder 60
thereon for attachment and removal of the substrate. A substrate
conveyance device 122 is arranged at the center of these units 102,
40, 20, and 120. The substrate conveyance device 122 comprises a
transfer robot that conveys the substrate among these units. As
will be described later, the aligner 40 according to the first
embodiment includes an organic substance desorption device (see
FIGS. 4, 6, etc.) that is configured to locally desorb an organic
substance existing at the edge section of the substrate before the
substrate is set in the substrate holder 60.
[0114] The fixing unit 120 is configured to be able to place two
substrate holders 60 thereon. In the fixing unit 120, the substrate
is delivered between one substrate holder 60 and the substrate
conveyance device 122, and then the substrate is delivered between
the other substrate holder 60 and the substrate conveyance device
122.
[0115] The processing unit 170B of the plating apparatus has a
stocker 124, a pre-wet bath 126, a pre-soak bath 128, a first
washing bath 130a, a blow bath 132, a second washing bath 130b, and
a plating bath 10. The stocker 124 is adapted for storage and
temporary provisional custody of the substrate holder 60. In the
pre-wet bath 126, the substrate is immersed in pure water. In the
pre-soak bath 128, the oxide film on the surface of the conductive
layer such as a seed layer formed on the surface of the substrate
is etched away. In the first washing bath 130a, the substrate after
the pre-soaking is washed along with the substrate holder 60 with a
washing liquid (pure water or the like). In the blow bath 132,
draining of the substrate after the washing is performed. In the
second washing bath 130b, the substrate that has been subjected to
the plating is washed with a washing solution along with the
substrate holder 60. The stocker 124, the pre-wet bath 126, the
pre-soak bath 128, the first washing bath 130a, the blow bath 132,
the second washing bath 130b, and the plating bath 10 are arranged
in this order.
[0116] The plating bath 10 has, for example, a plurality of plating
cells 134 provided with an overflow bath. Each of the plating cells
134 accommodates one substrate therein and immerses the substrate
in the plating solution held therein. By applying a voltage between
the substrate and the anode in the plating cell 134, plating such
as copper plating or the like is performed on the substrate
surface.
[0117] The plating apparatus has a substrate holder conveyance
device 140 adopting, for example, a linear motor system. The
substrate holder conveyance device 140 is located on the side of
each of these devices and configured to convey the substrate holder
60 together with the substrate among these devices. This substrate
holder conveyance device 140 has a first transporter 142 and a
second transporter 144. The first transporter 142 is configured to
convey a substrate among the fixing unit 120, the stocker 124, the
pre-wet bath 126, the pre-soak bath 128, the first washing bath
130a, and the blow bath 132. The second transporter 144 is
configured to convey the substrate among the first washing bath
130a, the second washing bath 130b, the blow bath 132, and the
plating bath 10. In another embodiment, the plating apparatus may
include only either of the first transporter 142 and the second
transporter 144, where the one transporter conveys the substrate
among the fixing unit 120, the stocker 124, the pre-wet bath 126,
the pre-soak bath 128, the first washing bath 130a, the second
washing bath 130b, the blow bath 132, and the plating bath 10.
[0118] FIG. 2 is a perspective view of the substrate holder 60 used
in the plating apparatus illustrated in FIG. 1. As illustrated in
FIG. 2, the substrate holder 60 includes a first holding member 65
made of, for example, vinyl chloride and having a rectangular flat
plate shape, and a second holding member 66 that is attached to the
first holding member 65 via a hinge 63 so as to be opened and
closed. A holding surface 68 for holding the substrate is provided
substantially at the center of the first holding member 65 of the
substrate holder 60. In addition, on the outer side of the holding
surface 68 of the first holding member 65, an inversed L-shaped
clamper 67 having a projecting portion projecting inward is
provided along the circumference of the holding surface 68.
[0119] A pair of substantially T-shaped hands 69 serving as support
portions for conveying the substrate holder 60 and suspending and
supporting the substrate holder 60 are connected to an end of the
first holding member 65 of the substrate holder 60. Inside the
stocker 124 illustrated in FIG. 1, the hand 69 is hooked on the
upper surface of the peripheral wall of the stocker 124 and thus
the substrate holder 60 is vertically suspended and supported.
Further, the hand 69 of the suspended and supported substrate
holder 60 is grasped by the first transporter 142 or the second
transporter 144, and thus the substrate holder 60 is conveyed.
Also, in the pre-wet bath 126, the pre-soak bath 128, the washing
baths 130a, 130b, the blow bath 132, and the plating bath 10, the
substrate holder 60 is suspended and supported on the peripheral
walls thereof via the hand 69.
[0120] In addition, the hand 69 includes an external contact (not
shown) for connecting to an external power supply unit. This
external contact is electrically connected to a plurality of
electrical conductors 73 (see FIG. 3) provided on the outer
periphery of the holding surface 68 via a plurality of wires.
[0121] The second holding member 66 includes a base portion 61
fixed to the hinge 63 and a ring-shaped seal holder 62 fixed to the
base portion 61. A retaining ring 64 for pressing and fixing the
seal holder 62 against the first holding member 65 is rotatably
mounted on the seal holder 62 of the second holding member 66. The
retaining ring 64 has a plurality of protrusions 64a protruding
outward at the outer circumferential portion thereof. The upper
surface of the protrusion 64a and the lower surface of the inward
protruding portion of the clamper 67 have tapered surfaces inclined
in opposite directions along the rotational direction.
[0122] When holding the substrate, the substrate is first placed on
the holding surface 68 of the first holding member 65 with the
second holding member 66 opened, and the second holding member 66
is closed. Subsequently, the retaining ring 64 is rotated in the
clockwise direction, and the protrusion 64a of the retaining ring
64 is slid into the inside (lower side) of the inward projecting
portion of the clamper 67. As a result, the first holding member 65
and the second holding member 66 are tightened and locked to each
other via the tapered surfaces provided on the retaining ring 64
and the clamper 67, respectively, and the substrate is held. When
taking the substrate out of the held state, the retaining ring 64
is rotated counterclockwise in a state where the first holding
member 65 and the second holding member 66 are locked. As a result,
the protrusion 64a of the retaining ring 64 is detached from the
inverted L-shaped clamper 67, and the substrate is taken out of the
held state.
[0123] FIG. 3 is a cross-sectional view illustrating an electrical
contact of the substrate holder 60 illustrated in FIG. 2. As
illustrated in FIG. 3, the substrate W is placed on the holding
surface 68 of the first holding member 65. A plurality of (one in
the figure) electrical conductors 73 connected to a plurality of
wires extending from an external contact provided in the hand 69
illustrated in FIG. 2 are arranged between the holding surface 68
and the first holding member 65. The electrical conductors 73 are
arranged on the outer side of the circumference of the substrate W
so as to be exposed in the state in which the end portion of the
electrical conductor 73 exhibits a spring characteristic on the
surface of the first holding member 65 on the side of the substrate
W when the substrate W is placed on the holding surface 68 of the
first holding member 65.
[0124] A seal member 70 which is pressed against the outer
peripheral surface of the substrate W and the first holding member
65 when the substrate W is held by the substrate holder 60 is
attached to the surface (lower surface in the drawing) of the seal
holder 62 facing the first holding member 65. The seal member 70
has a lip portion 70a for sealing the surface of the substrate W
and a lip portion 70b for sealing the surface of the first holding
member 65.
[0125] A support 71 is attached to the inside of the seal member 70
sandwiched between the pair of lips 70a, 70b. A plurality of
electrical contacts 72 that are configured to be able to receive
power from the electrical conductor 73 is fixed to the support 71,
for example, using screws or the like, and are arranged along the
circumference of the substrate W. The electrical contact 72 has an
electrical contact end 72a extending inwardly of the holding
surface 68 and a leg portion 72b configured to receive electricity
from the electrical conductor 73.
[0126] When the first holding member 65 and the second holding
member 66 illustrated in FIG. 2 are locked, then, as illustrated in
FIG. 3, the short lip portion 70a on the inner peripheral surface
side of the seal member 70 is pressed against the surface of the
substrate W, and the long lip portion 70b on the outer peripheral
surface side is pressed against the surface of the first holding
member 65. As a result, the lip portion 70a and the lip portion 70b
are reliably sealed and the substrate W is held.
[0127] In a region sealed by the seal member 70, that is, in a
region sandwiched between the pair of lips 70a, 70b of the seal
member 70, the electrical conductor 73 is electrically connected to
the leg portion 72b of the electrical contact 72, and the
electrical contact end 72a contacts the seed layer on the edge
section of the substrate W. Thus, while the substrate W is sealed
by the seal member 70 and held by the substrate holder 60, power
can be supplied to the substrate W via the electrical contact
72.
[0128] As described above, a resist pattern is formed in advance on
the substrate W on which the seed layer is formed. Before being
conveyed to the plating apparatus illustrated in FIG. 1, the
substrate W is irradiated with a UV or the like to remove the
resist residue on the substrate surface (ashing treatment) and
hydrophilization treatment (descum treatment) is performed thereon.
The substrate W that has been subjected to the ashing and descum
treatments is thereafter conveyed to the plating apparatus and held
by the substrate holder 60. Here, an oxide film may be created on
the seed layer on the edge section on which the resist of the
substrate W is not applied, or organic substances volatilized from
the resist may adhere to it due to passage of time after the ashing
and descum treatments. As illustrated in FIG. 3, the electrical
contact 72 contacts the edge section of the substrate W.
Accordingly, when an oxide film is created on the seed layer at the
edge section of the substrate W or organic substances adhere
thereto, the contact resistance of the electrical contact 72 of the
substrate holder 60 may problematically vary, causing deterioration
of the uniformity of the plated film thickness.
[0129] In view of this, according to this embodiment, the organic
substance desorption device is provided at the aligner 40
illustrated in FIG. 1, and organic substances created in the seed
layer on the edge section of the substrate W are desorbed
(removed). Note that, in this specification, the edge section of
the substrate W refers to a region where the substrate W can be
brought into contact with the electrical contact 72, or a region
closer to the peripheral portion side of the substrate W than the
portion where the seal member 70 is in contact when the substrate W
is held by the substrate holder 60. For example, in this
embodiment, it refers to a region on the outer peripheral side of a
portion where the lip portion 70a of the seal member 70 illustrated
in FIG. 3 abuts, and within a range of about 5 millimeters, and
more preferably within the range of about 2 mm, from the outer
peripheral portion of the substrate W toward the substrate
center.
[0130] FIG. 4 is a schematic top view of the aligner 40 illustrated
in FIG. 1. FIG. 5 is a schematic cross-sectional view of the
aligner 40 in the direction of the arrow 5-5 illustrated in FIG. 4,
and FIG. 6 is a schematic cross-sectional view of the aligner 40 in
the direction of the arrow 6-6 illustrated in FIG. 4. As
illustrated in FIGS. 4 to 6, the aligner 40 includes a base 41, a
rotating stage 42, an aligner light source 43, a photodetector 44,
and an organic substance desorption device 45 (corresponding to an
example of the edge section washing device).
[0131] The rotating stage 42 is configured to stick to the back
surface of the substrate W to rotate the substrate W in the
circumferential direction. The rotating stage 42 sticks to the
substrate W by an electrostatic adsorption or vacuum adsorption.
The aligner light source 43 is configured to irradiate with light
46 the edge section or a region near the edge section of the
substrate W rotated by the rotating stage 42. When the substrate W
is rotated and the notch of the substrate W is moved to a position
where it is irradiated with the light 46 from the aligner light
source 43, the light 46 passes through the notch and reaches the
photodetector 44. When the photodetector 44 has detected the light
46, the aligner 40 can recognize that the notch of the substrate W
is positioned directly below the aligner light source 43, so that
the orientation of the substrate W can be adjusted.
[0132] The organic substance desorption device 45 is a UV
irradiation device or a plasma emission device. In this embodiment,
a UV or plasma can be locally applied to the edge section of the
substrate W from above the substrate W. The organic substance
desorption device 45 can locally apply the UV or plasma to the edge
section of the substrate W before the substrate W is held by the
substrate holder 60. In other words, the area other than the edge
section of the substrate W is not exposed to the UV or plasma. By
rotating the substrate W by the rotating stage 42, the UV or plasma
can be efficiently applied over the entire periphery of the edge
section of the substrate W. When the organic substance adhering to
the edge section of the substrate W is irradiated with the UV or
plasma, the organic substance is decomposed to generate a volatile
substance, and the organic substance that has become the volatile
substance is volatilized and removed. It is preferable that the
distance between the UV irradiation source of the UV irradiation
device or the plasma emission port of the plasma emission device
and the substrate W is about 1 mm or more and about 10 mm or less.
If this distance is less than 1 mm, there is a possibility that the
substrate and the UV irradiation source or the plasma emission port
of the plasma emission device are in physical contact with each
other. Also, if this distance is over 10 mm, the UV or plasma may
not be radiated locally. In order to ensure that the substrate and
the UV irradiation source or the plasma emission port of the plasma
emission device are not brought into physical contact with each
other and to enable local irradiation, it is more preferable that
this distance be about 2 mm or more and about 5 mm or less.
[0133] For example, a high-pressure mercury lamp, a low-pressure
mercury lamp, a black light, a laser light source capable of
emitting light in the UV region, or the like can be adopted as the
UV light source if the organic substance desorption device 45 is a
UV irradiation device. Since a high-pressure mercury lamp,
low-pressure mercury lamp, and black light have light divergence
tendency, it is preferable when adopting any of these light sources
that the light source is placed in the vicinity of the substrate W
or only the edge section is irradiated with the UV using an optical
system. If the organic substance desorption device 45 is a plasma
emission device, for example, an atmospheric remote plasma device
or the like can be adopted.
[0134] The aligner 40 may further include a sensor
(spectrophotometer) configured to measure the absorbance by
irradiating the edge section of the substrate W with a light in the
ultraviolet region (200 nm to 380 nm), for example, a light having
a wavelength of 365 nm as excitation light from above the edge
section of the substrate W and observing a reflected light from the
edge section, or may further include a sensor (fluorescent
reflection film thickness meter) configured to monitor the
intensity of a reflected light by irradiating it with a light in
the fluorescent region.
[0135] This sensor (not shown) may be provided in the organic
substance desorption device 45 or separately provided in the
aligner 40. The control unit of the plating apparatus according to
this embodiment is configured to be capable of determining whether
or not the contaminant (including the organic substances and the
oxide film) at the edge section have been sufficiently removed
according to whether or not the value of the absorbance or the
fluorescence intensity measured by this sensor is larger than a
preset threshold value. For example, when it is determined that the
contaminants at the edge section have not been sufficiently
removed, the organic substance desorption device 45 may repeat the
process of locally emitting the UV or plasma to the edge section of
the substrate W. Also, if it is determined that the contaminants at
the edge section have been sufficiently removed, then desorption of
the organic substance is regarded as being completed and the
substrate W is conveyed to the fixing unit 120 by the substrate
conveyance device 122, which is followed by a series of plating
processes. In this way, whether or not contaminants are present at
the edge section of the substrate W is determined before the
plating process, and thereafter, the plating process is performed
on the substrate on which the contaminants do not remain at the
edge section, so that deterioration of in-plane uniformity of
plating film thickness of the substrate W due to variations in
contact resistance of the electrical contact of the substrate
holder 60, and the like can be more reliably prevented.
[0136] FIG. 7 is a flow chart illustrating a plating method
according to the first embodiment. In this plating method, first, a
resist pattern is formed on the substrate W before conveying the
substrate W to the plating apparatus illustrated in FIG. 1 (step
S601). Subsequently, UV irradiation is performed on the substrate W
on which the resist pattern has been formed, resist residues on the
surface of the substrate W are removed (ashing treatment), and a
hydrophilization process (descum treatment) of the resist surface
is performed (step S602). The processes in the steps S601 and S602
are performed in an appropriate device or devices other than the
plating apparatus illustrated in FIG. 1.
[0137] Subsequently, the substrate W is conveyed from the FOUP 102
in which the substrate W has been accommodated to the aligner 40 by
the substrate conveyance device 122. In the aligner 40, the edge
section of the substrate W is washed (step S603). Specifically, in
the aligner 40, a UV or plasma is locally applied to the edge
section of the substrate W by the organic substance desorption
device 45, and the organic substance is desorbed. At this point,
the orientation of the substrate W is adjusted by the aligner
40.
[0138] Although not described in the flow illustrated in FIG. 7, if
a sensor (not shown) is provided in the aligner 40, at least either
of the organic substance and the oxide film present at the edge
section of the substrate W is irradiated with a UV or plasma to
locally remove the at least one of them, and then the presence or
absence of the pollutants (including organic substances and oxide
films) at the edge section can be confirmed. Specifically, first,
the sensor (spectrophotometer or fluorescence reflection film
thickness meter) is positioned above the surface of the substrate W
arranged in the aligner 40. While the substrate W is rotated or
stopped by the aligner 40, the sensor is made to scan the substrate
from the central portion to the edge section thereof (or from the
edge section to the central portion of the substrate), and the
surface of the substrate W is irradiated with a light in the
ultraviolet region (200 nm to 380 nm), for example, a light having
a wavelength of 365 nm as excitation light from the sensor toward
the surface of the substrate W, and absorbance or fluorescence
intensity is measured.
[0139] The edge section that has been subjected to the UV or plasma
treatment and a plated surface that is not subjected to the UV or
plasma treatment exist on the surface of the substrate, and the
seed layer is formed on the entire surface of the substrate surface
(the plated surface and the edge section). The absorbance or the
fluorescence intensity of both the plated surface and the edge
section can be measured by scanning the plated surface and the edge
section using the sensor. The control unit of the plating apparatus
compares, for example, the absorbances of both the plated surface
and the edge section, and whether or not contaminants (including
the organic substances and the oxide film) in the edge section have
been sufficiently removed can be determined, for example, according
to whether or not the value of the ratio of the absorbance at the
edge section to the absorbance at the plated surface exceeds a
preset threshold value (for example, 50% or less). When the value
of the ratio is larger than the threshold value, it can be
determined that the contaminants (including the organic substance
and the oxide film) at the edge section are not sufficiently
removed. Also, when the value of the ratio is not larger than the
threshold value, it can be determined that the contaminants
(including the organic substances and the oxide film) at the edge
section have been sufficiently removed. In the case of measuring
the fluorescence intensity as well, whether or not contaminants at
the edge section of the substance have been sufficiently removed
can be determined by comparing the predetermined threshold value
and the measured value in the same manner.
[0140] Based on this determination, if it is determined that the
contaminants at the edge section are not sufficiently removed, the
process of locally radiating the UV or plasma to the edge section
of the substrate W may be repeated. If it is determined that the
contaminants at the edge section have been sufficiently removed,
desorption of the organic substance is regarded as completed, the
substrate is conveyed to the fixing unit 120 by the substrate
conveyance device 122, which is followed by a series of plating
processes. In this way, whether or not contaminants are present at
the edge section of the substrate W is determined before the
plating process, and thereafter, the plating process is performed
on the substrate on which the contaminants do not remain at the
edge section and deterioration of in-plane uniformity of plating
film thickness of the substrate W due to variations in contact
resistance of the electrical contacts of the substrate holder 60,
and the like can be more reliably prevented.
[0141] The substrate W whose edge section has been washed is
conveyed to the fixing unit 120 by the substrate conveyance device
122 and set in the substrate holder 60 (step S604). At this point,
since the organic substance at the edge section of the substrate W
is desorbed, the electrical contact of the substrate holder 60 is
brought into contact with the edge section of the washed substrate
W. This makes it possible to reduce variations in the contact
resistance of the electrical contact of the substrate holder 60 due
to the adhesion of organic substances.
[0142] The substrate W held by the substrate holder 60 is first
conveyed to the pre-wet bath 126 by the substrate holder conveyance
device 140, and the substrate W is immersed in the pure water
contained in the pre-wet bath 126 (step S605). Subsequently, the
substrate W is conveyed to the pre-soak bath 128, and the surface
of the substrate W is acid-washed (step S606). Specifically, the
substrate W is immersed in a chemical liquid such as sulfuric acid,
nitric acid or the like contained in the pre-soak bath 128, and the
oxide film on the surface of the seed layer formed on the surface
of the substrate is removed by etching.
[0143] Although not described in the flow illustrated in FIG. 7,
even when the acid-washed substrate W may be immersed in the pure
water contained in the first washing bath 130a and the chemical
liquid attached to the surface of the substrate W may be washed.
Subsequently, the substrate W is immersed in one of the plating
cells 134 of the plating bath 10, and a plating process is
performed (step S607). Quick damp rinse (QDR) treatment is
performed on the substrate W on which the plating film is formed on
the surface (step S608). Specifically, the substrate W is immersed
in the pure water contained in the second washing bath 130b and the
plating solution attached to the surface of the substrate W is
washed.
[0144] Subsequently, the substrate W held by the substrate holder
60 is conveyed to the fixing unit 120, and the substrate W is
detached from the substrate holder 60. The substrate conveyance
device 122 receives the substrate W from the fixing unit 120 and
conveys the substrate W to the spin rinse dryer 20. The surface of
the substrate W is washed and dried in the spin rinse dryer 20
(step S609).
[0145] As described above, according to this embodiment, it is made
possible to locally remove the organic substances present in the
edge section of the substrate W before the substrate is set in the
substrate holder 60. Accordingly, it is made possible to suppress
variations in the contact resistance of the electrical contact 72
of the substrate holder 60 due to the organic substance present at
the edge section of the substrate W without adversely affecting the
resist pattern formed on the surface of the substrate W, and
prevent deterioration of the uniformity of the plated film
thickness.
[0146] Also, according to this embodiment, a UV or plasma can be
locally emitted to the edge section of the substrate W. By virtue
of this, no UV or plasma is radiated to the surface other than the
edge section of the substrate W, i.e., the portion on the substrate
W where the resist is applied, so that the organic substance on the
edge section of the substrate W can be desorbed.
[0147] Further, according to this embodiment, since the organic
substance desorption device 45 is provided at the aligner 40, the
edge section of the substrate W can be processed by the UV
irradiation device or the plasma emission device while the
substrate is rotated by the aligner 40. Accordingly, it is not
necessary to provide a mechanism for rotating the substrate in the
organic substance desorption device 45, so that the cost can be
reduced. Further, by providing the organic substance desorption
device 45 in the aligner 40, it is made possible to reduce the
footprint of the plating apparatus as a whole.
[0148] Note that the organic substance desorption device 45 may be
provided in the plating apparatus separately from the aligner 40.
FIG. 8 is an overall schematic representation of another example of
the plating apparatus according to the first embodiment. As
illustrated in FIG. 8, the organic substance desorption device 45
is provided in the load/unload unit 170A separately from the
aligner 40. In this case, the aligner 40 will have a configuration
corresponding to the configurations illustrated in FIGS. 4 to 6
except that the organic substance desorption device 45 is omitted
therefrom. In the meantime, the organic substance desorption device
45 needs to have a mechanism similar to the rotating stage 42
illustrated in FIGS. 4 to 6 for rotating the substrate W. According
to the plating apparatus illustrated in FIG. 8, since the organic
substance desorption device 45 is provided separately from the
aligner 40, the process or processes of the organic substance
desorption device 45 and the process or processes of the aligner 40
can be separately performed from each other on multiple substrates
W. As a result, in the case where the throughput of the entire
processes is determined by the treatment time of the organic
substance desorption treatment because the organic substance
desorption treatment takes time, the throughput can be made higher
than that of the plating apparatus illustrated in FIG. 1. It may be
noted here that the organic substance desorption device 45 can also
be provided at the spin rinse dryer 20. Even in this case, the spin
rinse dryer 20 may include a sensor (spectrophotometer) configured
to measure the absorbance or a sensor (fluorescence reflection film
thickness meter) configured to monitor the intensity of a reflected
light by radiating a light in the fluorescent region and monitor
the intensity of the reflected light (not shown). In that case, the
sensor is positioned above the edge section of the substrate W
during or after the washing of the edge section. Then, the
substrate W is rotated, a light is radiated from the sensor to the
edge section of the substrate W, a light reflected from the
substrate W is received by the light receiving portion of the
sensor, and the fluorescence intensity or absorbance of the
reflected light is measured. Thus, it may be determined whether or
not the contaminants (at least either of the organic substance and
the oxide film) at the edge section of the substrate W have been
sufficiently removed. By such a configuration, whether or not
contaminants are present on the edge section of the substrate W is
determined before performing the plating process, and thereafter
the plating process can be performed on the substrate on which no
contaminants remain at the edge section, so that deterioration of
in-plane uniformity of plating film thickness of the substrate W
due to variations in contact resistance of the electrical contact
of the substrate holder 60, and the like can be more reliably
prevented. If the apparatus is configured to determine whether or
not a contaminant is present at the edge section of the substrate W
during the washing of the edge section of the substrate W, the end
point of the washing may be determined based on the determination
result of this sensor.
Second Embodiment
[0149] FIG. 9 is an overall schematic representation of the plating
apparatus according to a second embodiment. The second embodiment
differs from the plating apparatus illustrated in FIG. 1 of the
first embodiment in the features of the spin rinse dryer 20 and the
aligner 40. Since other features are similar to those of the first
embodiment, the same reference numerals are given to the same
features as those of the first embodiment, and explanations thereof
are omitted.
[0150] In the second embodiment, the aligner 40 does not include
the organic substance desorption device 45 described in the first
embodiment. In addition, the spin rinse dryer 20 has an oxide film
removal device configured to locally remove the oxide film present
at the edge section of the substrate before the substrate is set in
the substrate holder 60.
[0151] FIG. 10 is a schematic diagram illustrating the spin rinse
dryer 20 that includes the oxide film removal device. As
illustrated in the figure, the spin rinse dryer 20 has a rotating
stage 21, a substrate chuck 22, a DIW nozzle 23, and the oxide film
removal device 24 (corresponding to an example of the edge section
washing device). The substrate chuck 22 is configured to grasp the
outer peripheral portion of the substrate W. The rotating stage 21
is configured to rotate the substrate chuck 22, and rotates the
grasped substrate W in the circumferential direction as the
substrate chuck 22 rotates. The DIW nozzle 23 is configured to
supply deionized water (DIW) to a substantially central portion of
the substrate W. The DIW supplied to the substrate W receives the
centrifugal force by the rotation of the substrate W and flows
toward the outer peripheral portion of the substrate W. Although
not shown, the spin rinse dryer 20 has a cover that covers the
periphery of the substrate W so as to prevent the DIW of the
substrate W from scattering to the outside.
[0152] The oxide film removal device 24 is a chemical liquid supply
device configured to supply a chemical liquid 28 to the substrate,
and includes a chemical liquid nozzle 25 configured to supply the
chemical liquid 28, an arm 26 connected to the chemical liquid
nozzle 25, and a rotation shaft 27 configured to cause the arm 26
to pivot. It is preferable that the distance between the tip of the
chemical liquid nozzle 25 and the substrate W is about 1 mm or more
and about 10 mm or less. If the distance is less than 1 mm, there
is a possibility that the substrate and the chemical liquid nozzle
25 physically contact each other. Also, if this distance is over 10
mm, there is a possibility that the chemical liquid cannot be
supplied locally. In order to ensure that the substrate and the
chemical liquid nozzle 25 are not brought into physical contact
with each other and enable local supply of the chemical liquid, it
is more preferable that the distance between the tip of the
chemical liquid nozzle 25 and the substrate is set to about 2 mm or
more and about 5 mm or less.
[0153] In order to locally remove the oxide film present at the
edge section of the substrate W by the oxide film removal device
24, first, the oxide film removal device 24 causes the arm 26 to
pivot according to the diameter of the substrate W, and the
chemical liquid nozzle 25 is positioned above the edge section of
the substrate W. In the state where the chemical liquid nozzle 25
is positioned above the edge section of the substrate W, the DIW is
supplied from the DIW nozzle 23 to the substantially central
portion of the rotating substrate W, and the chemical liquid 28 is
ejected to the edge section of the rotating substrate W. The
chemical liquid 28 is supplied to the edge section of the substrate
W and flows toward the outer peripheral portion of the substrate W
under the centrifugal force due to the rotation of the substrate W.
Thereby, the oxide film removal device 24 can supply the chemical
liquid 28 locally to the edge section of the substrate W. In other
words, the regions other than the edge section of the substrate W
are substantially not exposed to the chemical liquid 28. By
rotating the substrate W by the rotating stage 21, the chemical
liquid 28 can be efficiently supplied over the entire periphery of
the edge section of the substrate W. When the chemical liquid 28 is
supplied to the oxide film created at the edge section of the
substrate W, the oxide film is dissolved and removed by the
chemical liquid 28. After supplying the chemical liquid 28 for a
predetermined time, the supply of the chemical liquid 28 is stopped
while the supply of the DIW is continued. As a result, the chemical
liquid 28 supplied to the edge section of the substrate W is washed
off. Here, the edge section of the substrate W refers, as mentioned
in the foregoing, to an area where the electrical contact 72 can be
brought into contact with the edge section of the substrate W, or a
region closer to the peripheral portion side of the substrate W
than the portion where the substrate W is in contact with the seal
member 70 when the substrate W is held by the substrate holder 60.
Meanwhile, the apparatus may also be configured such that, assuming
in advance that some of the chemical liquid can be scattered when
supplying the chemical liquid to the substrate in a spotwise
manner, the chemical liquid components and concentration are
specified such that the chemical liquid is unlikely to adversely
affect the resist pattern, and the oxide film in the peripheral
portion of the edge section of the substrate W is dissolved and
removed by the chemical liquid 28.
[0154] An acid such as dilute sulfuric acid, citric acid or the
like, which is unlikely to damage the seed layer on the substrate
W, can be adopted as the chemical liquid 28. In this embodiment, it
is preferable that the chemical liquid 28 is 3 wt % or more and 15
wt % or less of diluted sulfuric acid or 2 wt % or more and 20 wt %
or less of citric acid. If diluted sulfuric acid is less than 3 wt
% or citric acid is less than 2 wt %, there is a possibility that
the acid concentration is too low to properly remove the oxide
film. Also, if the diluted sulfuric acid exceeds 15 wt % or citric
acid exceeds 20 wt %, the acid concentration is too high and there
is a possibility that the seed layer on the edge section of the
substrate is melted.
[0155] FIG. 11 is a flow chart that illustrates a plating method
according to the second embodiment. The plating method according to
the second embodiment coincides in many aspects with the plating
method illustrated in FIG. 7 except for some aspects. Accordingly,
explanations of the same parts as those of the plating method of
FIG. 7 will be partly omitted.
[0156] The substrate W subjected to the ashing treatment and the
descum treatment in step S602 is conveyed to the plating apparatus
illustrated in FIG. 9. Subsequently, the substrate W is conveyed
from the FOUP 102 in which the substrate W has been accommodated to
the spin rinse dryer 20 by the substrate conveyance device 122. In
the spin rinse dryer 20, washing of the edge section of the
substrate W is performed (step S701). Specifically, in the spin
rinse dryer 20, the oxide film present at the edge section of the
substrate W is removed by the oxide film removal device 24.
[0157] Further, also in this embodiment, in order to measure the
state of the edge section of the substrate W, the spin rinse dryer
20 may include a sensor (spectrophotometer) configured to measure
the absorbance of the edge section by irradiating the edge section
with a light in the ultraviolet region (200 nm to 380 nm), for
example, a light having a wavelength of 365 nm as excitation light
from above the edge section of the substrate W or a sensor
(fluorescent reflection film thickness meter) configured to monitor
the intensity of a reflected light by irradiating it with a light
in the fluorescent region (not shown). In that case, the sensor is
positioned above the edge section of the substrate W during or
after the washing of the edge section. Then, the substrate W is
rotated, a light is radiated from the sensor to the edge section of
the substrate W, a light reflected from the substrate W is received
by the light receiving portion of the sensor, and the fluorescence
intensity or absorbance of the reflected light is measured. Thereby
whether or not the oxide film at the edge section of the substrate
W has been sufficiently removed may be determined to inspect the
state of the edge section. By such a configuration, whether or not
contaminants are present on the edge section of the substrate W is
determined before performing the plating process, and thereafter
the plating process can be performed on the substrate on which no
contaminants remain at the edge section, so that deterioration of
in-plane uniformity of plating film thickness of the substrate W
due to variations in contact resistance of the electrical contact
of the substrate holder 60, and the like can be more reliably
prevented.
[0158] The substrate W which has been subjected to the washing (in
some cases washing and inspection) of the edge section is conveyed
to the fixing unit 120 by the substrate conveyance device 122 and
set in the substrate holder 60 (step S604). At this point, since
the oxide film at the edge section of the substrate W has been
removed, the electrical contact of the substrate holder 60 is
brought into contact with the edge section of the washed substrate
W. This makes it possible to reduce variations in the contact
resistance of the electrical contact of the substrate holder 60
caused by the oxide film. The substrate W set in the substrate
holder 60 is processed in the subsequent steps S605 to S609.
[0159] As described above, according to the second embodiment, it
is made possible to locally remove the oxide film present at the
edge section of the substrate before the substrate is set in the
substrate holder 60. Accordingly, it is made possible to suppress
variations in the contact resistance of the electrical contact 72
of the substrate holder 60 due to the oxide film existing at the
edge section of the substrate W, without adversely affecting the
resist pattern formed on the surface of the substrate W, and
prevent deterioration of uniformity of the plating film
thickness.
[0160] In addition, according to the second embodiment, since the
oxide film removal device 24 is provided at the spin rinse dryer
20, the edge section of the substrate W can be processed with the
chemical liquid 28 while rotating the substrate by the spin rinse
dryer 20. Accordingly, the oxide film removal device 24 does not
need to include a mechanism for rotating the substrate and a
mechanism for preventing scattering of the chemical liquid 28, so
that the cost can be reduced. Also, since the spin rinse dryer 20
has a cover for preventing the liquid on the substrate W from
scattering, the chemical liquid 28 supplied from the chemical
liquid nozzle 25 can be prevented from scattering to the outside of
the spin rinse dryer 20. Further, by providing the oxide film
removal device 24 in the spin rinse dryer 20, it is made possible
to reduce the footprint of the plating apparatus as a whole
[0161] Since the seed layer is formed on the substrate W to be
plated, the seed layer may melt if the seed layer is unattended
with the chemical liquid 28 attached to the seed layer.
Accordingly, when the chemical liquid 28 adheres to a portion other
than the edge of the substrate W to be plated, for example, the
seed layer exposed via the opening of the resist pattern,
sufficient washing is required so that the chemical liquid 28 does
not remain there. According to the second embodiment, the chemical
liquid 28 can be locally supplied to the edge section of the
substrate W. This makes it possible to remove the oxide film
created at the edge section of the substrate without letting the
chemical liquid 28 adhere to the seed layer exposed via the opening
of the resist pattern. Therefore, compared to the case where the
chemical liquid 28 adheres to the entire surface of the substrate
W, the washing time of the substrate W can be greatly
shortened.
Third Embodiment
[0162] FIG. 12 is an overall schematic representation of a plating
apparatus according to a third embodiment. The plating apparatus
according to the third embodiment has a configuration in which the
spin rinse dryer 20 in the plating apparatus illustrated in FIG. 8
according to the first embodiment is replaced with the spin rinse
dryer 20 illustrated in FIG. 10 according to the second embodiment.
Since the other features are the same as those of the plating
apparatus illustrated in FIG. 8 of the first embodiment, the same
reference numerals are given to the same features as those of the
first embodiment, and explanations thereof will be omitted.
[0163] The plating apparatus illustrated in FIG. 12 includes the
spin rinse dryer 20 having the oxide film removal device 24
illustrated in FIG. 10, and an organic substance desorption device
45. Therefore, the present plating apparatus can locally remove
both the organic substance and the oxide film present at the edge
section of the substrate W.
[0164] FIG. 13 is a flow chart illustrating a plating method
according to the third embodiment. The plating method according to
the third embodiment is a method obtained by combining the step
S701 illustrated in FIG. 11 with the plating method illustrated in
FIG. 7. Specifically, as illustrated in FIG. 13, the substrate W
subjected to the ashing treatment and the descum treatment in the
step S602 is conveyed to the plating apparatus illustrated in FIG.
11. Subsequently, the substrate W is conveyed from the FOUP 102 in
which the substrate W has been accommodated to the aligner 40 by
the substrate conveyance device 122. In the aligner 40, the edge
section of the substrate W is washed (step S603). Specifically, in
the aligner 40, the organic substance present at the edge section
of the substrate W is desorbed by the organic substance desorption
device 45. At this point, the orientation of the substrate W is
adjusted by the aligner 40. Note that the edge section here refers
to a region that is closer to the peripheral portion side of the
substrate W than the portion where the seal member 70 is in contact
when the substrate W is held by the substrate holder 60, which is,
for example, within a range of about 5 mm, and more preferably
within a range of about 2 mm, from the outer peripheral portion of
the substrate W toward the substrate center.
[0165] Furthermore, also in this embodiment, in order to measure
the state of the edge section of the substrate, the aligner 40 may
include a sensor (spectrophotometer) configured to measure the
absorbance of the edge section by irradiating the edge section of
the substrate W with a light in the ultraviolet region (200 nm to
380 nm), for example, a light having a wavelength of 365 nm as
excitation light from above the edge section or a sensor
(fluorescent reflection film thickness meter) configured to monitor
the intensity of a reflected light by irradiating it with a light
in the fluorescent region (not shown). The control unit of the
plating apparatus is configured to be capable of determining
whether or not the contaminants (including the organic substance
and the oxide film) of the edge section have been sufficiently
removed according to whether or not the value of the absorbance or
the fluorescence intensity measured by this sensor is larger than a
preset threshold value. In that case, the sensor is positioned
above the edge section of the substrate W during or after the
washing of the edge section. Then, the substrate W is rotated, a
light is radiated from the sensor to the edge section of the
substrate W, a light reflected from the substrate W is received by
the light receiving portion of the sensor, and the fluorescence
intensity or absorbance of the reflected light is measured. Thus,
the apparatus may be configured to determine whether or not
contaminants (including organic substances and oxide films) at the
edge section of the substrate W have been sufficiently removed and
thereby determine whether or not contaminants are present at the
edge section. By such a configuration, whether or not contaminants
are present on the edge section of the substrate W is determined
before performing the plating process, and thereafter the plating
process can be performed on the substrate on which no contaminants
remain at the edge section, so that it is made possible to prevent
deterioration and the like of in-plane uniformity of the plating
film thickness of the substrate W due to variations in contact
resistance of electrical contact of the substrate holder 60. If the
apparatus is configured to determine whether or not a contaminant
is present at the edge section of the substrate W during the
washing of the edge section of the substrate W, the end point of
the washing may be determined based on the determination result of
this sensor. Furthermore, the presence or absence of a substrate W
which originally has an abnormality in the edge section can also be
determined based on the measurement result of the sensor.
[0166] The substrate W from which the organic substances at the
edge section have been desorbed is subsequently conveyed to the
spin rinse dryer 20 by the substrate conveyance device 122. In the
spin rinse dryer 20, washing of the edge section of the substrate W
is performed (step S701). Specifically, in the spin rinse dryer 20,
the oxide film existing at the edge section of the substrate W is
desorbed by the oxide film removal device 24. Note that the edge
section here refers to a region that is closer to the peripheral
portion side of the substrate W than the portion where the seal
member 70 is in contact when the substrate is held by the substrate
holder and, for example, if the substrate W is a 300 mm wafer,
within a range of about 5 mm, and more preferably within a range of
about 2 mm, from the outer peripheral portion of the substrate W
toward the substrate center, but it is also possible to specify the
chemical liquid components and concentration such that the chemical
liquid is unlikely to adversely affect the resist pattern, and
dissolve and remove the oxide film existing at and near the edge
section.
[0167] The substrate W whose edge section has been washed is
conveyed to the fixing unit 120 by the substrate conveyance device
122 and set in the substrate holder 60 (step S604). At this point,
since the organic substances and the oxide film at the edge section
of the substrate W have been removed, the electrical contact of the
substrate holder 60 is brought into contact with the edge section
of the washed substrate W. This makes it possible to reduce
variations in the contact resistance of the electrical contact of
the substrate holder 60 due to the organic substance and the oxide
film. The substrate W set in the substrate holder 60 is processed
in the subsequent steps S605 to S609.
[0168] As explained above, according to the third embodiment, it is
made possible to locally remove the organic substance and the oxide
film present at the edge section of the substrate before the
substrate is set in the substrate holder 60. Accordingly, it is
made possible to suppress variations in the contact resistance of
the electrical contact 72 of the substrate holder 60 due to the
organic substance and the oxide film present at the edge section of
the substrate W without adversely affecting the resist pattern
formed on the surface of the substrate W, and prevent deterioration
of the uniformity of the plated film thickness.
[0169] At the edge section of the substrate W, organic substances
may adhere to the oxide film. Accordingly, when the oxide film is
removed before desorbing the organic substance, it is difficult to
remove the oxide film in the portion where the organic substances
adhere. According to the third embodiment, since the oxide film is
removed after desorption of the organic substance, the organic
substances and the oxide film can be effectively removed. However,
in one embodiment, the organic substance desorption process (step
S603) may be performed after the chemical liquid washing of the
edge section (step S701).
Fourth Embodiment
[0170] FIG. 14 is an overall schematic representation of a plating
apparatus according to a fourth embodiment. The plating apparatus
of the fourth embodiment differs from the plating apparatus of FIG.
1 according to the first embodiment in that it includes a sponge
washing device 80 while it does not include the organic substance
desorption device 45. Since other features are similar to those of
the first embodiment, the same reference numerals are given to the
same features as those of the first embodiment, and explanations
thereof will be omitted.
[0171] The aligner 40 of the plating apparatus illustrated in FIG.
14 does not include the organic substance desorption device 45
described in the first embodiment. The sponge washing device 80 is
provided in the load/unload unit 170A and configured to locally
remove a particle or particles present at the edge section of the
substrate W.
[0172] FIG. 15 is a schematic side view of the sponge washing
device 80. As illustrated in the figure, the sponge washing device
80 has a rotation stage 81, a DIW nozzle 83, a sponge washing unit
84 (corresponding to an example of the edge section washing
device), and a cover 88. The rotation stage 81 is configured to
stick to the back surface of the substrate W to rotate the
substrate W in the circumferential direction. The rotation stage 81
sticks to the substrate W by an electrostatic adsorption or vacuum
adsorption. The DIW nozzle 83 is configured to supply DIW to a
substantially central portion of the substrate W. The DIW supplied
to the substrate W receives the centrifugal force by the rotation
of the substrate W and flows toward the outer peripheral portion of
the substrate W. The cover 88 covers the periphery of the substrate
W and prevents the DIW of the substrate W from scattering to the
outside.
[0173] The sponge washing unit 84 has a sponge head 85 configured
to physically wash the edge section of the substrate W, an arm 86
connected to the sponge head 85, and a rotation shaft 87 configured
to pivot the arm 86. The sponge head 85 is made of, for example,
polyvinyl alcohol (PVA) and is configured to be rotatable about a
vertical axis. Further, the rotation shaft 87 is configured to be
expanded and contracted in an axial direction.
[0174] In order to locally remove the particles present at the edge
section of the substrate W by the sponge washing unit 84, first,
the sponge washing device 80 makes the arm 86 pivot according to
the diameter of the substrate W, and the sponge head 85 is
positioned above the edge section of the substrate W. In the state
where the sponge head 85 is positioned above the edge section of
the substrate W, the rotation shaft 87 contracts downward in the
axial direction and the sponge head 85 is brought into abutment on
the edge section of the substrate W. The sponge washing unit 84
rotates the sponge head 85 in the state where the sponge head 85 is
in abutment on the edge section of the rotating substrate W. At
this point, the DIW is supplied to the substrate W by the DIW
nozzle 83. As a result, the sponge washing device 80 can locally
remove the particles at the edge section of the substrate W. Also,
a sensor (not shown) may be provided in the sponge washing device
80 to determine whether or not contaminants are present at the edge
section.
[0175] FIG. 16 is a flow chart illustrating a plating method
according to the fourth embodiment. The plating method according to
the fourth embodiment has the step S801 in place of the step S603
in the plating method illustrated in FIG. 7 according to the first
embodiment. Explanations of the same parts as those of the plating
method of FIG. 7 will be partly omitted.
[0176] In the flow illustrated in FIG. 16, the substrate W
subjected to the ashing and descum treatments in the step S602 is
conveyed to the plating apparatus illustrated in FIG. 14.
Subsequently, the substrate W is conveyed from the FOUP 102 in
which the substrate W has been accommodated to the sponge washing
device 80 by the substrate conveyance device 122. In the sponge
washing device 80, the edge section of the substrate W is washed
(step S801). Specifically, in the sponge washing device 80, the
particles present at the edge section of the substrate W are
removed by the sponge washing unit 84.
[0177] Also in this embodiment, in order to measure the state of
the edge section of the substrate W, the sponge washing device 80
may include a sensor (spectrophotometer) configured to measure the
absorbance of the edge section by irradiating the edge section with
a light in the ultraviolet region (200 nm to 380 nm), for example,
a light having a wavelength of 365 nm as excitation light from
above the edge section of the substrate W or a sensor (fluorescent
reflection film thickness meter) configured to monitor the
intensity of a reflected light by irradiating it with a light in
the fluorescent region (not shown). The control unit of the plating
apparatus is configured to be capable of determining whether or not
the contaminants (including the organic substance and the oxide
film) of the edge section have been sufficiently removed according
to whether or not the value of the absorbance or the fluorescence
intensity measured by this sensor is larger than a preset threshold
value. If the sensor is provided in the sponge washing device 80,
the sensor is positioned above the edge section of the substrate W
during or after washing of the edge section. Then, the substrate W
is rotated, the presence or absence of particles at the edge
section of the substrate W may be determined, and it may be
determined whether or not a contaminant exists in the edge section.
By such a configuration, whether or not contaminants are present at
the edge section of the substrate W is determined before performing
the plating process, and thereafter the plating process can be
performed on the substrate on which no contaminants remain at the
edge section, so that it is made possible to prevent deterioration
and the like of in-plane uniformity of the plating film thickness
of the substrate W due to variations in contact resistance of
electrical contact of the substrate holder 60. Further, if the
apparatus is configured to determine whether or not a contaminant
is present at the edge section of the substrate W during the
washing of the edge section of the substrate W, the end point of
the washing may be determined based on the determination result of
this sensor. Furthermore, the presence or absence of a substrate W
which originally has an abnormality in the edge section can also be
determined based on the measurement result of the sensor.
[0178] The substrate W whose edge section has been washed is
conveyed to the fixing unit 120 by the substrate conveyance device
122 and set in the substrate holder 60 (step S604). At this point,
since the particles at the edge section of the substrate W have
been removed, the electrical contact of the substrate holder 60 is
brought into contact with the edge section of the washed substrate
W. This makes it possible to reduce variations in the contact
resistance of the electrical contact of the substrate holder 60
caused by the particles. The substrate W set in the substrate
holder 60 is processed in the subsequent steps S605 to S609.
[0179] As described above, according to the fourth embodiment,
particles present at the edge section of the substrate W can be
locally removed before the substrate is set in the substrate holder
60. Accordingly, it is made possible to prevent particles from
being caught between the electrical contact of the substrate holder
60 and the seed layer on the edge section of the substrate W, and
it is made possible to suppress deterioration of contact resistance
due to particles.
Fifth Embodiment
[0180] FIG. 17 is an overall schematic representation of a plating
apparatus according to a fifth embodiment. The plating apparatus of
the fifth embodiment differs from the plating apparatus of FIG. 1
according to the first embodiment in that it includes a sponge
chemical liquid washing device 90. Since other features are similar
to those of the first embodiment, the same reference numerals are
given to the same features as those of the first embodiment, and
explanations thereof will be omitted.
[0181] The sponge chemical liquid washing device 90 illustrated in
FIG. 17 is provided in the load/unload unit 170A and configured to
locally remove the oxide film and particles present at the edge
section of the substrate W. Although not illustrated in FIG. 17,
the sponge chemical liquid washing device 90 may also include a
sensor (not shown) above and near the edge section of the substrate
W and may be configured to determine whether or not contaminants
are present at the edge section. In this case, a sensor
(spectrophotometer) may be provided which is configured to measure
the absorbance of the edge section by irradiating the edge section
with a light in the ultraviolet region (200 nm to 380 nm), for
example, a light having a wavelength of 365 nm as excitation light
from above the edge section of the substrate W or a sensor
(fluorescent reflection film thickness meter) may be provided which
is configured to monitor the intensity of a reflected light by
irradiating it with a light in the fluorescent region (not shown).
The control unit of the plating apparatus is configured to be
capable of determining whether or not the contaminants (including
the organic substance and the oxide film) of the edge section have
been sufficiently removed according to whether or not the value of
the absorbance or the fluorescence intensity measured by this
sensor is larger than a preset threshold value.
[0182] FIG. 18 is a schematic side view of the sponge chemical
liquid washing device 90. As illustrated in the figure, the sponge
chemical liquid washing device 90 includes a rotation stage 91, a
DIW nozzle 93, a sponge washing unit 84, an oxide film removal
device 94 (corresponding to an example of the edge section washing
device), and a cover 98. The rotation stage 91 is configured to
stick to the back surface of the substrate W to rotate the
substrate W in the circumferential direction. The rotation stage 91
sticks to the substrate W by an electrostatic adsorption or vacuum
adsorption.
[0183] The oxide film removal device 94 is a chemical liquid supply
device for supplying a chemical liquid to the substrate and
includes a chemical liquid nozzle 95 configured to supply the
chemical liquid, an arm 96 connected to the chemical liquid nozzle
95, and a rotation shaft 97 configured to pivot the arm 96. It is
preferable that the distance between the tip of the chemical liquid
nozzle 95 and the substrate W is about 1 mm or more and about 10 mm
or less. If the distance is less than 1 mm, there is a possibility
that the substrate and the chemical liquid nozzle 95 physically
contact each other. Also, if this distance is over 10 mm, there is
a possibility that the chemical liquid cannot be supplied locally.
In order to ensure that the substrate and the chemical liquid
nozzle 95 are not brought into physical contact with each other and
to be able to supply the chemical liquid locally, the distance
between the tip of the chemical liquid nozzle 95 and the substrate
is set to about 2 mm or more and about 5 mm or less.
[0184] In order to locally remove the oxide film present at the
edge section of the substrate W by the sponge chemical liquid
washing device 90, first, the oxide film removal device 94 pivots
the arm 96 according to the diameter of the substrate W, and the
chemical liquid nozzle 95 is positioned above the edge section of
the substrate W. In the state where the chemical liquid nozzle 95
is positioned above the edge section of the substrate W, the DIW is
supplied from the DIW nozzle 93 to the substantially central
portion of the rotating substrate W, and the chemical liquid is
ejected to the edge section of the rotating substrate W. The
chemical liquid is supplied to the edge section of the substrate W
and flows toward the outer peripheral portion of the substrate W
under the centrifugal force by the rotation of the substrate W. As
a result, the oxide film removal device 94 can locally supply the
chemical liquid to the edge section of the substrate W. In other
words, the regions other than the edge section of the substrate W
is substantially not exposed to the chemical liquid. By rotating
the substrate W by the rotation stage 91, it is made possible to
efficiently supply the chemical liquid over the entire periphery of
the edge section of the substrate W. When the chemical liquid is
supplied to the oxide film created at the edge section of the
substrate W, the oxide film is dissolved and removed by the
chemical liquid. After supplying the chemical liquid for a
predetermined time, the supply of the chemical liquid is stopped
while the supply of the DIW is continued. As a result, the chemical
liquid supplied to the edge section of the substrate W is washed
off. Here, the edge section of the substrate W refers, as described
in the foregoing, to a region where the electrical contact 72 is
allowed to be brought into contact with the edge section of the
substrate W, or a region closer to the peripheral edge side of the
substrate W than the portion where the substrate W is in contact
with the seal member 70 when the substrate W is held by the
substrate holder 60. However, the apparatus may also be configured
such that, assuming in advance that some of the chemical liquid can
be scattered when supplying the chemical liquid to the substrate in
a spotwise manner, the chemical liquid components and concentration
are specified so that the chemical liquid is unlikely to adversely
affect the resist pattern, and the oxide film at the peripheral
portion of the edge section of the substrate W are dissolved and
removed by the chemical liquid 28.
[0185] Also, the sponge chemical liquid washing device 90 can
remove the oxide film at the edge section of the substrate W by the
oxide film removal device 94 and locally remove the particles
present at the edge section of the substrate W by the sponge
washing unit 84. In this embodiment, in order to measure presence
or absence of contaminants at the edge section of the substrate W,
the sponge chemical liquid washing device 90 may include a sensor
(spectrophotometer) configured to measure the absorbance of the
edge section by irradiating the edge section with a light in the
ultraviolet region (200 nm to 380 nm), for example, a light having
a wavelength of 365 nm as excitation light from above the edge
section of the substrate W or a sensor (fluorescent reflection film
thickness meter) configured to monitor the intensity of a reflected
light by irradiating it with a light in the fluorescent region (not
shown). The control unit of the plating apparatus is configured to
be capable of determining whether or not the contaminants
(including the organic substance and the oxide film) of the edge
section have been sufficiently removed according to whether or not
the value of the absorbance or the fluorescence intensity measured
by this sensor is larger than a preset threshold value. In that
case, the substrate W is rotated in a state where the sensor is
positioned above the edge section of the substrate W during or
after the washing of the edge section, and thereby whether or not
contaminants exist at the edge section can be determined. By such a
configuration, whether or not contaminants are present at the edge
section of the substrate W is determined before performing the
plating process, and thereafter the plating process can be
performed on the substrate on which no contaminants remain at the
edge section, so that it is made possible to prevent deterioration
and the like of in-plane uniformity of the plating film thickness
of the substrate W due to variations in contact resistance of
electrical contact of the substrate holder 60. Further, if the
apparatus is configured to determine whether or not a contaminant
is present at the edge section of the substrate W during the
washing of the edge section of the substrate W, the end point of
the washing may be determined based on the determination result of
this sensor. Furthermore, the presence or absence of a substrate W
which originally has an abnormality in the edge section can also be
determined based on the measurement result of the sensor.
[0186] FIG. 19 is a flow chart illustrating a plating method
according to the fifth embodiment. The plating method according to
the fifth embodiment includes the step S901 in addition to (the
steps of) the plating method illustrated in FIG. 7 according to the
first embodiment. Explanations of the same parts as those of the
plating method of FIG. 7 will be partly omitted.
[0187] In the step S603, the organic substance desorption device 45
(see FIGS. 4 to 6) provided at the aligner 40 desorbs the organic
substances present at the edge section of the substrate W.
Subsequently, the substrate W is conveyed to the sponge chemical
washing device 90 by the substrate conveyance device 122. In the
sponge chemical liquid washing device 90, the edge section of the
substrate W is washed (step S901). Specifically, in the sponge
chemical liquid washing device 90, the particles and the oxide film
present at the edge section of the substrate W are removed.
Although not illustrated in FIG. 19, whether or not contaminants
are present at the edge section may be determined in order to
determine presence or absence of an organic substance, oxide film,
particles, or the like at the edge section of the substrate W that
has been washed.
[0188] The substrate W whose edge section has been washed is
conveyed to the fixing unit 120 by the substrate conveyance device
122 and set in the substrate holder 60 (step S604). At this point,
the electrical contact of the substrate holder 60 is brought into
contact with the edge section of the washed substrate W. This makes
it possible to reduce variations in the contact resistance of the
electrical contact of the substrate holder 60 caused by the
particles. The substrate W set in the substrate holder 60 is
processed in the subsequent steps S605 to S609.
[0189] As described above, according to the fifth embodiment, it is
made possible to locally remove the organic substance, the oxide
film, and the particles present at the edge section of the
substrate W before the substrate is set in the substrate holder 60.
Accordingly, it is made possible to suppress variations in the
contact resistance of the electrical contact 72 of the substrate
holder 60 due to the organic substance, the oxide film, and the
particles present at the edge section of the substrate W, and
prevent deterioration of the uniformity of the plating film
thickness.
Sixth Embodiment
[0190] FIG. 20 is an overall schematic representation of a plating
apparatus according to a sixth embodiment. The plating apparatus of
the sixth embodiment significantly differs from the plating
apparatuses of the first embodiment to the fifth embodiment in that
plating is performed on a rectangular (square) substrate. In the
following description, detailed explanations of the same features
as those of the plating apparatus of the first embodiment will be
omitted.
[0191] The plating apparatus of the sixth embodiment includes a
FOUP 102, a fixing unit 120, and a substrate conveyance device 122.
As will be described later, the fixing unit 120 according to the
sixth embodiment has an organic substance desorption device
configured to locally remove organic substances present at the edge
section of the rectangular substrate before the substrate is set in
the substrate holder 60. In the plating apparatus of the sixth
embodiment, a substrate holder 60 capable of holding the
rectangular substrate is used. The fixing unit 120 is configured to
cause the substrate holder 60 to hold the rectangular substrate
after locally desorbing the organic substance present at the edge
section of the rectangular substrate by the organic substance
desorption device.
[0192] The plating apparatus further includes a stocker 124, a
pre-wet bath 126, an activation bath 129, a blow bath 132, and a
plating bath 10. In the activation bath 129, the surface of the
substrate after pre-wet is washed with an acid or the like to
activate it. The stocker 124, the pre-wet bath 126, the activation
bath 129, the blow bath 132, and the plating bath 10 are arranged
in this order. Further, the plating apparatus has a washing and
drying device 135 for washing and drying the plated rectangular
substrate.
[0193] FIG. 21 is a flow chart illustrating a plating method
according to the sixth embodiment. In this plating method, first,
before conveying the rectangular substrate to the plating apparatus
illustrated in FIG. 20, a resist pattern is formed on the
rectangular substrate (step S2101). Subsequently, the rectangular
substrate on which the resist pattern has been formed is irradiated
with a UV to remove the resist residue on the surface of the
rectangular substrate (ashing treatment) and the resist surface is
subjected to hydrophilic treatment (descum treatment) (step S2102).
The processes in the steps S2101 and S2102 are performed in an
appropriate device or devices other than the plating apparatus
illustrated in FIG. 20
[0194] Subsequently, the rectangular substrate is conveyed from the
FOUP 102 in which the rectangular substrate has been accommodated
to the fixing unit 120 by the substrate conveyance device 122. In
the fixing unit 120, the edge section of the rectangular substrate
is washed (step S2103). Specifically, in the fixing unit 120, a UV
or plasma is locally applied to the edge section of the rectangular
substrate by the organic substance desorption device, and the
organic substance is desorbed.
[0195] Although not described in the flow illustrated in FIG. 21,
if a sensor (not shown) is provided in the fixing unit 120, the UV
or plasma is applied to the organic substance present at the edge
section of the rectangular substrate to locally remove it, and then
the presence or absence of contaminants (including organic
substance) at the edge section can be checked. Specifically, first,
a sensor (a spectrophotometer or a fluorescence reflection film
thickness meter) is positioned above the surface of the rectangular
substrate arranged in the organic substance desorption apparatus
provided at the fixing unit 120. While the sensor is made to scan
the rectangular substrate from the central portion to the edge
section thereof (or from the edge section to the substrate central
portion), light in the ultraviolet region (200 nm to 380 nm), for
example, light with a wavelength of 365 nm is emitted from the
sensor toward the surface of the rectangular substrate as an
excitation light, and absorbance or fluorescence intensity is
measured.
[0196] The edge section subjected to UV or plasma treatment and the
plated surface not subjected to the UV or plasma treatment exist on
the surface of the rectangular substrate. Also, the seed layer is
formed on the entire area of the rectangular substrate surface
(plated surface and edge section). By scanning the plated surface
and the edge section with the sensor, it is made possible to
measure the absorbance or the fluorescence intensity of both the
plated surface and the edge section. The control unit (not shown)
of the plating apparatus compares, for example, the absorbances of
both the plated surface and the edge section and is capable of
determining whether or not the contaminants (including an organic
substance and an oxide film) at the edge section have been
sufficiently removed according to whether or not the value of the
ratio of the absorbance at the edge section to the absorbance at
the plating surface exceeds a preset threshold value (e.g., 50% or
less). When the value of the ratio is larger than the threshold
value, it can be determined that the contaminants (including the
organic substance and the oxide film) at the edge section are not
sufficiently removed. Also, when the value of the ratio is not
larger than the threshold value, it can be determined that the
contaminants (including the organic substance and the oxide film)
at the edge section have been sufficiently removed. Also, in the
case of measuring the fluorescence intensity, by comparing the
predetermined threshold value and the measured value in the same
manner, it is made possible to determine whether or not
contaminants at the edge section of the substance have been
sufficiently removed.
[0197] On the basis of this determination, if it is determined that
the contaminants at the edge section are not sufficiently removed,
the process of locally radiating UV or plasma to the edge section
of the rectangular substrate may be repeated. Also, if it is
determined that the contaminants at the edge section have been
sufficiently removed, it is assumed that desorption of the organic
substance has been completed, the substrate is conveyed to the
respective treatment baths by the substrate holder conveyance
device 140, and a series of plating processes are performed. In
this manner, it is determined whether or not contaminants are
present at the edge section of the rectangular substrate before the
plating process, and thereafter the plating processes are performed
on the rectangular substrate on which no contaminants remain at the
edge section, by virtue of which deterioration of in-plane
uniformity of plated film thickness of the rectangular substrate
due to variations in contact resistance of the electrical contacts
of the substrate holder 60, and the like can be more reliably
prevented.
[0198] The rectangular substrate whose edge section has been washed
is set in the substrate holder 60 by the fixing unit 120 (step
S2104). At this point, since the organic substance at the edge
section of the rectangular substrate has been desorbed, the
electric contact of the substrate holder 60 is brought into contact
with the edge section of the washed rectangular substrate. This
makes it possible to reduce variations in the contact resistance of
the electrical contact of the substrate holder 60 due to the
adhesion of organic substances.
[0199] The rectangular substrate held by the substrate holder 60 is
first conveyed to the pre-wet bath 126 by the substrate holder
conveyance device 140, and the substrate W is then immersed in the
pure water stored in the pre-wet bath 126 (step S2105).
Subsequently, the rectangular substrate is conveyed to the
activation bath 129, and the surface of the substrate W is
activated (step S2106).
[0200] The rectangular substrate is immersed in one of the plating
cells 134 of the plating bath 10 and plating process is performed
(step S2107). The rectangular substrate having the plating film
formed on its surface is blow-dried in the blow bath 132 (step
S2108). Subsequently, the rectangular substrate held by the
substrate holder 60 is conveyed to the fixing unit 120, and the
rectangular substrate is detached from the substrate holder 60. The
substrate conveyance device 122 receives the rectangular substrate
from the fixing unit 120 and conveys the rectangular substrate to
the washing and drying device 135. The surface of the rectangular
substrate is washed and dried in the washing and drying device 135
(step S2109).
[0201] Next, the processes in the step S2103 illustrated in FIG. 21
will be described in detail. FIG. 22 is a schematic side view of an
example of the organic substance desorption device 50 provided at
the fixing unit 120. The organic substance desorption device 50
constitutes a UV irradiation device or a plasma emission device. As
illustrated in FIG. 22, the organic substance desorption device 50
includes a substrate support table 55 (corresponding to an example
of the rotation mechanism), a first actuator 53 (corresponding to
an example of the actuator), a second actuator 52 (corresponding to
an example of the actuator), a head unit 51, and a control unit 54.
The substrate support table 55 is configured to stick to the back
surface of the rectangular substrate S1 and rotates the rectangular
substrate S1 in the circumferential direction. The substrate
support table 55 sticks to the rectangular substrate S1 by
electrostatic adsorption or vacuum adsorption.
[0202] The head unit 51 is configured such that a UV or plasma can
be locally applied to the edge section of the rectangular substrate
S1 from above the rectangular substrate S1 arranged on the
substrate support table 55. That is, when the head unit 51 is
configured to radiate a UV, the organic substance desorption device
50 constitutes a UV irradiation device, and when the head unit 51
is configured to emit plasma, then the organic substance desorption
device 50 constitutes a plasma emission device. In the organic
substance desorption device 50, UV or plasma can be locally applied
to the edge section of the rectangular substrate S1 before the
substrate is held by the substrate holder 60. In other words, the
regions other than the edge section of the rectangular substrate S1
are not exposed to UV or plasma.
[0203] The first actuator 53 and the second actuator 52 can move
the head unit 51 in the horizontal direction. Specifically, the
first actuator 53 can move the head unit 51 in the horizontal
direction and in the first direction of the linear direction, and
the second actuator 52 can move it in the second direction
orthogonal to the first direction. In the illustrated example, the
head unit 51 can be moved along the edge sections of the
rectangular substrate S1 by the first actuator 53 and the distance
d2 from the end portion of the rectangular substrate S1 to the
position of application of UV or plasma can be adjusted by the
second actuator 52. In this embodiment, the position of the head
unit 51 is adjusted such that the distance d2 is about 5 mm or
less, more preferably about 2 mm or less so that the UV or plasma
is applied to the region closer to the outer peripheral side than
the region where the lip portion 70a of the seal member 70 of the
substrate holder 60 is in contact. In this embodiment, the first
direction or the second direction is not a unidirectional direction
but a bidirectional direction such as a plus direction and a minus
direction on an X axis, for example.
[0204] Further, the head unit 51 is configured to be movable in the
vertical direction by an elevating mechanism (not shown). It is
preferable that the distance d1 between the UV irradiation source
of the head unit 51 or the plasma emission port and the rectangular
substrate S1 is about 1 mm or more and about 10 mm or less. If the
distance is less than 1 mm, there is a possibility that the
rectangular substrate S1 and the UV irradiation source or the
plasma emission port physically contact each other. Also, if this
distance d1 is larger than 10 mm, there is a possibility that UV or
plasma cannot be radiated locally. In order to ensure that the
rectangular substrate and the UV irradiation source or the plasma
emission port are not brought into physical contact with each other
and to enable local irradiation, it is preferable that the distance
d1 should be set to about 2 mm or more and about 5 mm or less.
[0205] The organic substance desorption device 50 further includes
a head unit 51, a first actuator 53, a second actuator, and a
control unit 54 for controlling the elevating mechanism (not
shown). Also, as illustrated in FIG. 22, in order to prevent UV or
plasma radiated from the head unit 51 from diffusing toward the
center side of the rectangular substrate S1, the organic substance
desorption device 50 may include a mask 57 for shielding the center
side of the rectangular substrate S1 from the UV or plasma.
[0206] FIGS. 23A to 23E are plan views of the organic substance
desorption device 50 illustrating the process of desorbing the
organic substances at the edge section of the rectangular substrate
S1 in the organic substance desorption device 50 illustrated in
FIG. 22. As illustrated in FIG. 23A, first, the organic substance
desorption device 50 adjust the position of the head unit 51 in the
vertical direction by the elevating mechanism (not shown) and
adjusts the position of the head unit 51 on one of the four edge
sections of the rectangular substrate S1 by the second actuator 52.
Subsequently, the control unit 54 of the organic substance
desorption device 50 controls the head unit 51 and the first
actuator 53 to irradiate the edge section of the rectangular
substrate S1 with the UV or plasma while moving the head unit 51 by
the first actuator 53 along the edge section of the rectangular
substrate S1 and washes one of the edge sections.
[0207] When one of the edge sections has been washed, the organic
substance desorption device 50 rotates the substrate support table
55 (see FIG. 22) to rotate the rectangular substrate S1 by 90
degrees as illustrated in FIG. 23B. At this point, the control unit
54 controls the head unit 51 and the substrate support table 55 so
as to stop the radiation of UV or plasma from the head unit 51 and
then rotate the substrate support table 55. In other words, the
head unit 51 and the substrate support table 55 are controlled such
that the radiation of UV or plasma from the head unit 51 and the
rotation of the rectangular substrate S1 by the substrate support
table 55 are not performed at the same time. By virtue of this, it
is made possible to prevent UV or plasma from being radiated to an
unintended area on the rectangular substrate S1.
[0208] As illustrated in FIG. 23B, the organic substance desorption
device 50 adjusts the position of the head unit 51 by the second
actuator 52 such that it corresponds to the edge section of the
rectangular substrate S1 while stopping the emission of UV or
plasma. In this embodiment, since the second actuator 52 is
provided, even when the rectangular substrate S1 has the long side
and the short side as illustrated in FIGS. 23A to 23E, it is made
possible to adjust the position of the head unit 51 such that it
corresponds to the edge section of the rectangular substrate
S1.
[0209] Subsequently, the organic substance desorption device 50
moves the head unit 51 along the edge section of the rectangular
substrate S1 by the first actuator 53 while radiating UV or plasma
from the head unit 51, and one of the other edge sections is
washed. Similarly, as illustrated in FIGS. 23C and 23D, the organic
substance desorption device 50 rotates the rectangular substrate S1
by 90 degrees every time one of the edge sections is washed, and
thus washes each edge section.
[0210] When the washing of the edge sections on the four sides of
the rectangular substrate S1 is completed, the organic substance
desorption device 50 further rotates the rectangular substrate S1
by 90 degrees to make the rectangular substrate S1 return to the
same position (home position) as in FIG. 23 A (FIG. 23E). In this
manner, the edge sections of the four sides of the rectangular
substrate S1 are washed. In the organic substance desorption device
50 illustrated in FIGS. 22 to 23E, the first actuator 53, the
second actuator 52, and the head unit 51 are included, but a
plurality of these may be provided. In that case, it is made
possible to reduce the time required for washing of the edge
section.
[0211] FIG. 24 is a schematic side view of another example of the
organic substance desorption device 50 provided at the fixing unit
120. In the organic substance desorption device 50 illustrated in
FIG. 24, unlike the organic substance desorption device 50
illustrated in FIG. 22, the substrate support table 55 is
configured not to rotate. Instead, the organic substance desorption
device 50 illustrated in FIG. 24 has a pivot shaft 56 that causes
the head unit 51 to pivot, the first actuator 53, and the second
actuator 52. The pivot shaft 56 is positioned so that its center
axis passes through substantially the center of the rectangular
substrate S1. The head unit 51, the first actuator 53, and the
second actuator 52 connected directly or indirectly to the pivot
shaft 56 so that the head unit 51 can be positioned above the edge
section of the rectangular substrate S1 as illustrated in FIG. 24.
The control unit 54 also controls driving of the pivot shaft 56 in
addition to the head unit 51, the first actuator 53, and the second
actuator 52.
[0212] FIGS. 25A to 25E are plan views of the organic substance
desorption device 50 illustrating the process of desorbing an
organic substance at the edge section of the rectangular substrate
S1 with the organic substance desorption device 50 illustrated in
FIG. 24. As illustrated in FIG. 25A, first, the organic substance
desorption device 50 adjusts the position of the head unit 51 in
the vertical direction by the elevating mechanism (not shown) and
adjusts the position of the head unit 51 by the pivot shaft 56 and
the second actuator 52 so that it corresponds to one of the four
edge sections of the rectangular substrate S1. Subsequently, the
control unit 54 of the organic substance desorption device 50
controls the head unit 51 and the first actuator 53 such that the
head unit 51 radiates UV or plasma, moves the head unit 51 along
the edge section of the rectangular substrate S1 by the first
actuator 53, and washes one of the edge sections.
[0213] When one of the edge sections is washed, the organic
substance desorption device 50 rotates the pivot shaft 56 and turns
the head unit 51 by 90 degrees as illustrated in FIG. 25B. At this
point, the control unit 54 controls the head unit 51 and the pivot
shaft 56 so as to turn the head unit 51 after stopping the emission
of UV or plasma from the head unit 51. In other words, the head
unit 51 and the pivot shaft 56 are controlled so that the UV or
plasma radiation from the head unit 51 and the pivoting of the head
unit 51 by the pivot shaft 56 are not performed at the same time.
Thereby, it is made possible to prevent UV or plasma from being
radiated to an unintended area on the rectangular substrate S1.
[0214] As illustrated in FIG. 25B, the organic substance desorption
device 50 adjusts the position of the head unit 51 by the second
actuator 52 so that it corresponds to the edge section of the
rectangular substrate S1 while stopping the emission of UV or
plasma. Subsequently, the organic substance desorption device 50
moves the head unit 51 along the edge section of the rectangular
substrate S1 by the first actuator 53 while radiating UV or plasma
from the head unit 51, and one of the other edge sections is
washed. Similarly, as illustrated in FIGS. 25C and 25D, the organic
substance desorption device 50 turns the head unit 51 by 90 degrees
about the pivot shaft 56 every time the one of the edge sections is
washed and each edge section is washed.
[0215] When the washing of the edge sections on the four sides of
the rectangular substrate S1 is completed, the organic substance
desorption device 50 further turns the head unit 51 by 90 degrees
and make the head portion return to the same position (home
position) as in FIG. 25 A (FIG. 25E). In this manner, the edge
sections of the four sides of the rectangular substrate S1 are
washed. In the organic substance desorption device 50 illustrated
in FIGS. 24 to 25E, the pair of pivot shafts 56, the first actuator
53, the second actuator 52, and the head unit 51 are included, but
a plurality of these components may also be provided. In that case,
it is made possible to reduce the time required for washing the
edge section.
[0216] FIG. 26 is a schematic side view of another example of the
organic substance desorption device 50 provided at the fixing unit
120. In the organic substance desorption device 50 illustrated in
FIG. 26, unlike the organic substance desorption device 50
illustrated in FIG. 22, two head portions are provided.
Specifically, the organic substance desorption device 50 includes a
first head unit 51a, a second head unit 51b, and two second
actuators 52a, 52b that correspond to the first head unit 51a and
the second head unit 51b. As illustrated in FIG. 26, the first head
unit 51a and the second head unit 51b are provided at positions
opposed to each other with the first actuator 53 residing
therebetween. Accordingly, the first head unit 51a and the second
head unit can reciprocate in the same direction by the second
actuators 52a, 52b.
[0217] FIGS. 27A to 27C are plan views of the organic substance
desorption device 50 illustrating the process of desorbing the
organic substances at the edge section of the rectangular substrate
S1 in the organic substance desorption device 50 illustrated in
FIG. 26. As illustrated in FIG. 27A, first, the organic substance
desorption device 50 adjusts the position of the head unit 51 in
the vertical direction by the elevating mechanism (not shown) and
adjusts the positions of the first head unit 51a and the second
head unit 51b by the second actuators 52a, 52b so that they
correspond to the opposing two of the four edge sections of the
rectangular substrate S1. Subsequently, the control unit 54 of the
organic substance desorption device 50 controls the first head unit
51a, the second head unit 51b, and the first actuator 53 to radiate
UV or plasma from the first head unit 51a and the second head unit
51b, move the first head unit 51a and the second head unit 51b
along the edge section of the rectangular substrate S1 by the first
actuator 53, and thus wash the two opposing edge sections.
[0218] When the two opposing edge sections have been washed, the
organic substance desorption device 50 rotates the substrate
support table 55 (see FIG. 26) to rotate the rectangular substrate
S1 by 90 degrees as illustrated in FIG. 27B. At this point, the
control unit 54 stops the radiation of UV or plasma from the first
head unit 51a and the second head unit 51b, and then rotates the
substrate support table 55, and controls the first head unit 51a
and the second head unit 51b, and the substrate support table 55 so
as to rotate the substrate support table 55. By virtue of this, it
is made possible to prevent the UV or plasma from being radiated to
an unintended area on the rectangular substrate S1.
[0219] As illustrated in FIG. 27B, the organic substance desorption
device 50, while the radiation of UV or plasma is stopped, adjusts
the positions of the first head unit 51a and the second head unit
51b by the second actuators 52a, 52b such that they correspond to
the opposing two edge sections of the rectangular substrate S1.
Subsequently, while radiating UV or plasma from the first head unit
51a and the second head unit 51b, the organic substance desorption
device 50 moves the first head unit 51a and the second head unit
51b along the edge sections of the rectangular substrate S1 by the
first actuator 53 so as to wash the two opposing edge sections.
[0220] When the washing of the edge sections on the four sides of
the rectangular substrate S1 is completed, the organic substance
desorption device 50 further rotates the rectangular substrate S1
by 270 degrees and make the rectangular substrate S1 return to the
same positions (home positions) as in FIG. 27 A (FIG. 27C). In this
manner, the edge sections of the four sides of the rectangular
substrate S1 are washed. The organic substance desorption device 50
illustrated in FIGS. 26 and 27A to 27 C has the first head unit 51a
and the second head unit 51b. Accordingly, as compared with the
organic substance desorption device 50 illustrated in FIGS. 22 and
23A to 23E, it is made possible to reduce the time for irradiating
the rectangular substrate S1 with UV or plasma and the time for
rotating the rectangular substrate S1. Also, although the organic
substance desorption device 50 illustrated in FIGS. 26 to 27C has a
pair of the first actuators 53, the second actuators 52a and 52b,
the first head unit 51a, and the second head unit 51b, it may have
multiple pairs thereof. In that case, it will be made possible to
reduce the time required for washing the edge sections.
[0221] FIG. 28 is a schematic side view of another example of the
organic substance desorption device 50 provided at the fixing unit
120. In the organic substance desorption device 50 illustrated in
FIG. 28, unlike the organic substance desorption device 50
illustrated in FIG. 24, two head units are provided. Specifically,
the organic substance desorption device 50 includes a first head
unit 51a, a second head unit 51b, and two second actuators 52a, 52b
corresponding to the first head unit 51a and the second head unit
51b. As illustrated in FIG. 28, the first head unit 51a and the
second head unit 51b are provided at positions opposed to each
other with the first actuator 53 residing therebetween.
Accordingly, the first head unit 51a and the second head unit 51b
can reciprocate in the same direction by the second actuators 52a,
52b.
[0222] FIGS. 29A to 29C are plan views of the organic substance
desorption device 50 illustrating the process of desorbing the
organic substances at the edge section of the rectangular substrate
S1 in the organic substance desorption device 50 illustrated in
FIG. 28. As illustrated in FIG. 29A, first, the organic substance
desorption device 50 adjusts the positions of the first head unit
51a and the second head unit 51b in the vertical direction by the
elevating mechanism (not shown) and adjusts the positions of the
first head unit 51a and the second head unit 51b by the pivot shaft
56 and the second actuators 52a, 52b such that they correspond to
the two opposing edge sections of the rectangular substrate S1.
Subsequently, the control unit 54 of the organic substance
desorption device 50 controls the first head unit 51a, the second
head unit 51b, and the first actuator 53 to radiate UV or plasma
from the first head unit 51a and the second head unit 51b, move the
first head unit 51a and the second head unit 51b along the edge
section of the rectangular substrate S1 by the first actuator 53,
and wash one of the edge sections.
[0223] When the two opposed edge sections are washed, the organic
substance desorption device 50 rotates the pivot shaft 56 and turns
the first head unit 51a and the second head unit 51b by 90 degrees
as illustrated in FIG. 29B. At this point, the control unit 54
controls the first head unit 51a, the second head unit 51b, and the
pivot shaft 56 such that radiation of UV or plasma from the first
head unit 51a and the second head unit 51b is stopped and then the
first head unit 51a and the second head unit 51b pivot. By virtue
of this, it is made possible to prevent UV or plasma from being
radiated to an unintended area on the rectangular substrate S1.
[0224] As illustrated in FIG. 29B, the organic substance desorption
device 50, while the radiation of UV or plasma is stopped, adjusts
the positions of the first head unit 51a and the second head unit
51b by the second actuators 52a, 52b such that they correspond to
the edge sections of the rectangular substrate S1. Subsequently,
the organic substance desorption device 50, while radiating UV or
plasma from the first head unit 51a and the second head unit 51b,
moves the first head unit 51a and the second head unit 51b along
the edge section of the rectangular substrate S1 by the first
actuator 53 and washes the opposite two edge sections.
[0225] When the washing of the edge sections on the four sides of
the rectangular substrate S1 is completed, the organic substance
desorption device 50 further rotates the first head unit 51a and
the second head unit 51b by 270 degrees and make the first head
unit 51a and the second head unit 51b return to the same positions
(home positions) as in FIG. 29A (FIG. 29C). In this manner, the
edge sections of the four sides of the rectangular substrate S1 are
washed. The organic substance desorption device 50 illustrated in
FIGS. 28 and 29A to 29C has the first head unit 51a and the second
head unit 51b. Accordingly, compared to the organic substance
desorption device 50 illustrated in FIGS. 24 and 25A to 25E, it is
made possible to reduce the time for irradiating the rectangular
substrate S1 with UV or plasma and the time for rotating the head
portion. Also, the organic substance desorption device 50
illustrated in FIGS. 28 to 29C has a pair of pivot shafts 56, the
first actuator 53, the second actuators 52a and 52b, the first head
unit 51a, and the second head unit 51b. However, multiple pairs of
these components may be provided. In that case, it will be made
possible to reduce the time required for washing the edge
sections.
[0226] In the case where the organic substance desorption device 50
of the sixth embodiment described above is a UV irradiation device,
as the UV light source, for example, a high-pressure mercury lamp,
a low-pressure mercury lamp, a black light, or a laser light source
capable of emitting light in the UV region, and the like may be
adopted. Since a high-pressure mercury lamp, low-pressure mercury
lamp, and black light have a light divergence tendency, it is
preferable in the case of adopting these light sources that the
light source is placed in the vicinity of the substrate W, or only
the edge section is irradiated with UV using an optical system.
When the organic substance desorption device 50 is a plasma
emission device, for example, an atmospheric remote plasma device
or the like can be adopted.
[0227] In the sixth embodiment, the organic substance desorption
device 50 is described as being provided at the fixing unit 120,
but it is not limited thereto, and it may be provided at another
unit or may be provided as a separate device in the plating
apparatus. In addition, although the organic substance desorption
device 50 is configured to wash the edge sections of the four sides
of the rectangular substrate, it is also possible to wash only the
edge sections of two opposing sides, for example. In that case, it
is made possible to reduce the number of rotations of the
rectangular substrate S1 or the number of turns of the head unit
51. Further, the mask 57 illustrated in FIG. 22 can also be adopted
in the other organic substance desorption device 50 illustrated in
FIGS. 24 to 29C.
[0228] Although the embodiments of the present invention have been
described in the foregoing, the embodiments of the invention
described above is presented for facilitating the understanding of
the present invention and does not limit the present invention. The
present invention can be modified and improved without departing
from the spirit of the invention, and it will be readily
appreciated that equivalents thereof are included in the present
invention. In addition, it is possible to combine or omit as
appropriate the individual constituent elements described in the
scope of claims and the specification within the range where at
least some of the above-mentioned problems can be solved or the
range where at least some of the effects can be exhibited. For
example, the organic substance desorption device 45, the oxide film
removal device 24, and the sponge washing device 80 for washing the
edge section of the substrate W described in FIGS. 1 to 19 can be
combined as appropriate.
REFERENCE SIGNS LIST
[0229] 10: plating bath [0230] 20: spin rinse dryer [0231] 24, 94:
oxide film removal device [0232] 25: chemical liquid nozzle [0233]
28: chemical liquid [0234] 40: aligner [0235] 45: organic substance
desorption device [0236] 50: organic substance desorption device
[0237] 51: head unit [0238] 51a: first head unit [0239] 51b: second
head unit [0240] 52, 52a, 52b: second actuator [0241] 53: first
actuator [0242] 54: control unit [0243] 55: substrate support table
[0244] 56: pivot shaft [0245] 60: substrate holder [0246] 80:
sponge washing device [0247] 84: sponge washing unit
* * * * *