U.S. patent application number 14/326439 was filed with the patent office on 2015-01-15 for wet processing apparatus and plating apparatus.
The applicant listed for this patent is EBARA CORPORATION. Invention is credited to Yoshitaka MUKAIYAMA, Yoichi NAKAGAWA, Junitsu YAMAKAWA.
Application Number | 20150013905 14/326439 |
Document ID | / |
Family ID | 52276174 |
Filed Date | 2015-01-15 |
United States Patent
Application |
20150013905 |
Kind Code |
A1 |
NAKAGAWA; Yoichi ; et
al. |
January 15, 2015 |
WET PROCESSING APPARATUS AND PLATING APPARATUS
Abstract
A wet processing apparatus, such as a plating apparatus, and an
etching apparatus, is disclosed. A wet processing apparatus
includes a substrate-holder advancing mechanism configured to
elevate a movable support to raise a substrate holder until the
substrate holder is separated from a fixed support, move the
movable support together with the substrate holder by a
predetermined distance toward a holder takeout position, lower the
movable support until the substrate holder is supported on the
fixed support and the movable support is separated from the
substrate holder, and move the movable support by the predetermined
distance toward a holder put-in position.
Inventors: |
NAKAGAWA; Yoichi; (Tokyo,
JP) ; MUKAIYAMA; Yoshitaka; (Tokyo, JP) ;
YAMAKAWA; Junitsu; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EBARA CORPORATION |
Tokyo |
|
JP |
|
|
Family ID: |
52276174 |
Appl. No.: |
14/326439 |
Filed: |
July 8, 2014 |
Current U.S.
Class: |
156/345.23 ;
118/423; 204/269 |
Current CPC
Class: |
C23C 18/1632 20130101;
C23C 18/1619 20130101; H01L 21/67086 20130101; C23F 1/08 20130101;
C25D 17/06 20130101; H01L 21/67757 20130101; C25D 17/001
20130101 |
Class at
Publication: |
156/345.23 ;
204/269; 118/423 |
International
Class: |
C23C 18/16 20060101
C23C018/16; C23F 1/08 20060101 C23F001/08; C25D 17/06 20060101
C25D017/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 10, 2013 |
JP |
2013-144239 |
Mar 19, 2014 |
JP |
2014-056714 |
Claims
1. A wet processing apparatus comprising: a substrate holder
configured to hold a substrate; a processing bath configured to
store a processing liquid therein; and a substrate-holder advancing
mechanism configured to move the substrate holder from a holder
put-in position to a holder takeout position in the processing bath
while keeping the substrate, held by the substrate holder, immersed
in the processing liquid, wherein the substrate-holder advancing
mechanism includes a fixed support configured to support the
substrate holder and suspend the substrate holder in the processing
bath, a movable support disposed adjacent to the fixed support and
configured to support the substrate holder, and an actuator
configured to elevate the movable support to raise the substrate
holder until the substrate holder is separated from the fixed
support, move the movable support together with the substrate
holder by a predetermined distance toward the holder takeout
position, lower the movable support until the substrate holder is
supported on the fixed support and the movable support is separated
from the substrate holder, and move the movable support by the
predetermined distance toward the holder put-in position.
2. The wet processing apparatus according to claim 1, wherein the
actuator comprises a first actuator configured to elevate and lower
the movable support, and a second actuator configured to
horizontally move the movable support.
3. The wet processing apparatus according to claim 1, further
comprising: a transporter configured to horizontally transport the
substrate holder; and a lifter configured to vertically transport
the substrate holder between the transporter and the
substrate-holder advancing mechanism, the lifter being configured
to lower the substrate holder to immerse the substrate, held by the
substrate holder, in the processing liquid in the processing bath
and raise the substrate holder from the processing bath.
4. The wet processing apparatus according to claim 1, wherein: the
substrate holder has outwardly-projecting portions; and the fixed
support has a plurality of recesses into which the projecting
portions of the substrate holder are to be fitted.
5. The wet processing apparatus according to claim 4, wherein the
movable support has a plurality of recesses into which the
projecting portions of the substrate holder are to be fitted.
6. A plating apparatus for plating a substrate, the plating
apparatus comprising: a substrate holder configured to hold the
substrate; and a plurality of plating sections arranged in
parallel, wherein each of the plating sections includes a plurality
of processing baths used for plating of the substrate, and a
substrate-holder transporter configured to transport the substrate
holder, holding the substrate, between the processing baths, and
wherein a maintenance space is provided between the plating
sections.
7. The plating apparatus according to claim 6, wherein the
maintenance space extends parallel to the substrate-holder
transporter.
8. The plating apparatus according to claim 6, wherein a piping
space in which pipes for conveying processing liquids to the
processing baths are disposed is formed below the maintenance
space.
9. The plating apparatus according to claim 6, wherein a utility
fluid introduction port configured to supply a utility fluid, which
is necessary for operation of the plating apparatus, to the plating
sections is provided below the maintenance space.
10. The plating apparatus according to claim 6, further comprising:
a substrate transfer section disposed adjacent to the maintenance
space and configured to transfer the substrate to the substrate
holder transporter.
11. The plating apparatus according to claim 10, wherein the
substrate transfer section includes a spin-rinse-dryer configured
to dry the substrate by rotating the substrate, and the
spin-rinse-dryer is disposed adjacent to the maintenance space.
12. The plating apparatus according to claim 6, wherein the plating
sections are electroless plating sections.
13. The plating apparatus according to claim 6, wherein the plating
sections are electroplating sections.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This document claims priorities to Japanese Patent
Application No. 2013-144239 filed Jul. 10, 2013 and Japanese Patent
Application No, 201456714 filed Mar. 19, 2014, the entire contents
of which are hereby incorporated by reference.
BACKGROUND
[0002] An electroless plating apparatus is known which performs
plating of a substrate, such as a wafer, by immersing the substrate
in a plating solution in a plating bath. As shown in FIG. 8, in
such an electroless plating apparatus, a number of substrate
holders 101, each holding a substrate W, are suspended in a plating
bath 100, and the substrates W are immersed in a plating solution.
While the substrate holders 101 are moved horizontally in the
plating bath 100, a metal film is deposited on the surface of each
substrate W. After a predetermined processing time has elapsed
since the substrates W were immersed in the plating solution held
in the plating bath 100, the substrates W are raised from the
plating bath 100.
[0003] In a plating process that entails a long processing time, it
is common practice to arrange the substrates W with a narrow
spacing therebetween in the plating bath 100 in order to increase a
throughput so that a large number of the substrates W are immersed
in the plating solution. The narrow spacing between the substrates
W, however, has the following drawback. When the substrates W are
moved horizontally, a plating solution existing between adjacent
substrates W moves together with the substrates W, and thus is not
likely to be replaced with a new plating solution. This will lead
to insufficient supply of metal ions to the surface of each of the
substrates W, resulting in a failure to form a metal film having a
uniform thickness on the substrate of each substrate W.
[0004] In electroless plating of a substrate W, as the plating
reaction progresses, a gas, such as hydrogen gas, is produced as a
reaction by-product. The gas does not all rise to a surface of the
plating solution, and the gas partly remains as bubbles on the
surface of the substrate W. The gas bubbles remaining on the
substrate W can interfere with uniform deposition of a metal film
on the surface of the substrate W. It is therefore necessary to
remove the gas bubbles from the surface of the substrate W.
[0005] Electroless plating is a technique to form a metal film on a
target surface of a substrate by chemically reducing metal ions in
a plating solution without passing an electric current through the
plating solution. Such electroless plating is widely used in
nickel-phosphorus plating, nickel-boron plating, copper plating for
a printed circuit board, etc. in particular, electroless plating
finds applications in wire bonding and formation of a metal layer,
such as Co (cobalt) or Ni (nickel), on a surface of a conductive
pad for electrical connection with solder bumps (see e.g., Japanese
laid-open patent publication No. 2001-267356).
[0006] Plating apparatuses can be classified roughly into a
single-substrate processing type and a batch processing type. A
known electroless plating apparatus of the single-substrate
processing type performs processing of a substrate while rotating
the substrate held in a horizontal position (see e.g., Japanese
laid-open patent publication No. 2002-129344). Such an electroless
plating apparatus, especially when it is used to form a metal layer
on a conductive pad, may have a drawback of low throughput due to a
long overall plating time. Plating apparatuses of the batch
processing type, on the other hand, has the following problems: As
substrates are becoming larger these days, a transport mechanism of
a carrier that holds a batch of substrates is becoming larger, thus
leading to an increased installation area of the plating
apparatus.
[0007] As substrates become larger and plating apparatuses become
larger in scale, it becomes difficult for an operator to reach
components (e.g., a plating bath, a substrate cleaning machine,
etc.) of a plating apparatus, and as a result it becomes difficult
to perform maintenance work on the plating apparatus.
[0008] It has been conventionally proposed to provide a plurality
of processing lines to perform plating of substrates in parallel so
as to increase the throughput or enhance the versatility of a
system (see e.g., Japanese laid-open patent publications No.
06-158395 and No. 2001-335995). This system, however, requires use
of a larger-scale plating apparatus which entails difficult
maintenance work,
SUMMARY OF THE INVENTION
[0009] It is therefore a first object to provide a wet processing
apparatus which can achieve uniform processing of a substrate.
[0010] It is a second object to provide a plating apparatus which,
while achieving a high throughput, allows an operator to easily
reach components of the plating apparatus, thus facilitating
maintenance work on the plating apparatus.
[0011] The below-described embodiments are directed to a wet
processing apparatus for processing a substrate, such as a wafer,
with a processing liquid, such as a plating solution or an etching
liquid, and to a plating apparatus for plating a surface of a
substrate, such as a wafer.
[0012] In an embodiment, there is provided a wet processing
apparatus comprising: a substrate holder configured to hold a
substrate; a processing bath configured to store a processing
liquid therein; and a substrate-holder advancing mechanism
configured to move the substrate holder from a holder put-in
position to a holder takeout position in the processing bath while
keeping the substrate, held by the substrate holder, immersed in
the processing liquid, wherein the substrate-holder advancing
mechanism includes a fixed support configured to support the
substrate holder and suspend the substrate holder in the processing
bath, a movable support disposed adjacent to the fixed support and
configured to support the substrate holder, and an actuator
configured to elevate the movable support to raise the substrate
holder until the substrate holder is separated from the fixed
support, move the movable support together with the substrate
holder by a predetermined distance toward the holder takeout
position, lower the movable support until the substrate holder is
supported on the fixed support and the movable support is separated
from the substrate holder, and move the movable support by the
predetermined distance toward the holder put-in position.
[0013] In an embodiment, the actuator comprises a first actuator
configured to elevate and lower the movable support, and a second
actuator configured to horizontally move the movable support.
[0014] In an embodiment, the wet processing apparatus further
comprises: a transporter configured to horizontally transport the
substrate holder; and a lifter configured to vertically transport
the substrate holder between the transporter and the
substrate-holder advancing mechanism, the lifter being configured
to lower the substrate holder to immerse the substrate, held by the
substrate holder, in the processing liquid in the processing bath
and raise the substrate holder from the processing bath.
[0015] In an embodiment, the substrate holder has
outwardly-projecting portions, and the fixed support has a
plurality of recesses into which the projecting portions of the
substrate holder are to be fitted.
[0016] In an embodiment, the movable support has a plurality of
recesses into which the projecting portions of the substrate holder
are to be fitted.
[0017] In an embodiment, there is provided a plating apparatus for
plating a substrate, comprising: a substrate holder configured to
hold the substrate; and a plurality of plating sections arranged in
parallel, wherein each of the plating sections includes a plurality
of processing baths used for plating of the substrate, and a
substrate-holder transporter configured to transport the substrate
holder, holding the substrate, between the processing baths, and
wherein a maintenance space is provided between the plating
sections.
[0018] In an embodiment, the maintenance space extends parallel to
the substrate-holder transporter.
[0019] In an embodiment, a piping space in which pipes for
conveying processing liquids to the processing baths are housed is
formed below the maintenance space.
[0020] In an embodiment, a utility fluid introduction port
configured to supply a utility fluid, which is necessary for
operation of the plating apparatus, to the plating sections is
provided below the maintenance space.
[0021] In an embodiment, the plating apparatus further comprises: a
substrate transfer section disposed adjacent to the maintenance
space and configured to transfer the substrate to the substrate
holder transporter.
[0022] In an embodiment, the substrate transfer section includes a
spin-rinse-dryer configured to dry the substrate by rotating the
substrate, and the spin-rinse-dryer is disposed adjacent to the
maintenance space.
[0023] In an embodiment, the plating sections are electroless
plating sections.
[0024] In an embodiment, the plating sections are electroplating
sections.
[0025] According to the wet processing apparatus of the
above-described embodiments, a substrate holder is moved from the
holder put-in position to the holder takeout position in the
processing bath, while a substrate, held by the substrate holder,
is kept immersed in a processing liquid and is moved up and down
repeatedly in the processing solution. Because the surface of the
substrate moves relative to the processing liquid, replacement of
the processing liquid in contact with the substrate is promoted
and, in addition, bubbles adhering to the surface of the substrate
can be removed. It therefore becomes possible to achieve uniform
processing of the substrate.
[0026] The plating apparatus according to the above-described
embodiments is provided with the maintenance space disposed between
the plating sections. Therefore, an operator can easily access
components of the plating apparatus and can easily perform
maintenance work on the components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a schematic plan view of an electroless plating
apparatus according to one embodiment;
[0028] FIG. 2 is a diagram showing a substrate holder;
[0029] FIG. 3 is a diagram showing a holding arm of the substrate
holder;
[0030] FIG. 4 is a perspective view of a first plating bath and a
substrate-holder advancing mechanism;
[0031] FIG. 5 is a diagram illustrating the operation of the
substrate-holder advancing mechanism;
[0032] FIG. 6A is a diagram showing a substrate holder before it is
raised by first actuators;
[0033] FIG. 6B is a diagram showing the substrate holder after it
is raised by the first actuators;
[0034] FIG. 7 is a perspective view of the first plating bath, the
substrate-holder advancing mechanism, and lifters;
[0035] FIG. 8 is a perspective view of a plating bath for
performing electroless plating of substrates;
[0036] FIG. 9 is a schematic plan view of an electroless plating
apparatus according to another embodiment;
[0037] FIG. 10 is a diagram showing a substrate holder;
[0038] FIG. 11 is a diagram showing a holding arm of the substrate
holder;
[0039] FIG. 12 is a diagram showing the electroless plating
apparatus of FIG. 9 as viewed in a direction of arrow A;
[0040] FIG. 13 is a schematic cross-sectional view taken along line
B-B of FIG. 9; and
[0041] FIG. 14 is a schematic plan view of an electroless plating
apparatus according to yet another embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0042] Embodiments of the present invention will now be described
with reference to the drawings.
[0043] A wet processing apparatus is an apparatus for processing a
substrate, such as a wafer, with use of a processing liquid, such
as a plating solution or an etching liquid. An electroless plating
apparatus and a wet etching apparatus are examples of the wet
processing apparatus. An electroless plating apparatus is a plating
apparatus for plating a substrate surface with metal without
passing an electric current through a plating solution. A wet
etching apparatus is an etching apparatus for etching away a
photoresist coating on a substrate surface by immersing the
substrate in a liquid, such as an organic solvent, or for removing
a seed layer of e.g., copper from a substrate surface by immersing
the substrate in an etching liquid comprising a mixture of sulfuric
acid and hydrogen peroxide. The following description illustrates
an electroless plating apparatus as one embodiment of the wet
processing apparatus, although the wet processing apparatus is not
limited to the electroless plating apparatus.
[0044] FIG. 1 is a schematic plan view of an electroless plating
apparatus according to one embodiment. As shown in FIG. 1, the
electroless plating apparatus includes a frame 1, loading ports 2
on which wafer cassettes, each housing substrates W (e.g., wafers)
therein, are placed, a controller 3 for controlling operation of
the electroless plating apparatus, and an aligner 4 for aligning an
orientation flat or a notch of a substrate W in a predetermined
direction. The electroless plating apparatus further includes a
spin-rinse-dryer (SRD) 6 for drying a plated substrate W by
rotating it at a high speed, a storage bath 14 for storing a
plurality of substrate holders 42 in a vertical position, a
substrate loader 10 for loading a substrate W to be plated into a
substrate holder 42 and taking a plated substrate W out of a
substrate holder 42, and a substrate transport robot 12 for
transporting a substrate W.
[0045] A travel mechanism 5 is installed along an arrangement
direction of the loading ports 2. The substrate transport robot 12
is installed on the travel mechanism 5. The aligner 4 is disposed
adjacent to the travel mechanism 5. The substrate transport robot
12 moves on the travel mechanism 5 and accesses the wafer cassette
set on one of the loading ports 2, takes a substrate W to be plated
out of the wafer cassette, and transfers the substrate W to the
substrate loader 10.
[0046] In the frame 1, there are disposed a pretreatment unit 16
for performing a pretreatment of a surface of a substrate W (e.g.,
removal of a copper oxide layer formed on the substrate surface)
and a nuclei forming unit 18 for forming e.g., palladium nuclei on
the surface of the substrate W. The pretreatment unit 16 includes a
pretreatment bath 16a for storing a pretreatment solution for
pretreating the surface of the substrate W, and a rinsing bath 16b
for rinsing the substrate W, which has been immersed in the
pretreatment solution, with a rinsing liquid (e.g., pure water).
The nuclei forming unit 18 includes a nuclei forming bath 18a for
forming palladium nuclei on the surface of the substrate W, and a
rinsing bath 18b for rinsing the substrate W, on which palladium
nuclei have been formed, with a rinsing liquid (e.g., pure
water).
[0047] The electroless plating apparatus further includes a first
plating unit (or a first processing unit) 20 for forming e.g., a
cobalt (Co) layer on the surface of the substrate W by electroless
plating, and a second plating unit (or a second processing unit) 24
for forming e.g., a gold (Au) layer on the surface of the substrate
W by electroless plating. The first plating unit 20 includes a
first plating bath (or a first processing bath) 20a for storing a
plating solution (or a first processing liquid), such as a cobalt
plating solution, and a rinsing bath 20b for rinsing the substrate
W, which has been immersed in the plating solution in the first
plating bath 20a, with a rinsing liquid (e.g., pure water).
[0048] The second plating unit 24 includes a second plating bath
(or a second processing bath) 24a for storing a plating solution
(or a second processing liquid), such as a gold plating solution,
and a rinsing bath 24b for rinsing the substrate W, which has been
immersed in the plating solution in the second plating bath 24a,
with a rinsing liquid (e.g., pure water). The pretreatment unit 16,
the nuclei forming unit 18, the first plating unit 20, the second
plating unit 24, and the storage bath 14 are arranged in series in
this order.
[0049] The first plating unit 20 and the second plating unit 24
each includes an overflow bath (not shown). The plating solution
that has overflown the plating bath 20a or 24a flows into the
overflow bath, and is returned through a circulation line (not
shown) to the plating bath 20a or 24a. Each circulation line is
provided with a filter and a plating solution temperature
regulator.
[0050] The substrate loader 10 is disposed adjacent to the storage
bath 14. The substrate loader 10 includes a table 26 on which a
substrate holder 42 is placed in a horizontal position, and a
substrate-holder tilting mechanism 28 for standing and leaning the
substrate holder 42. The substrate-holder tilting mechanism 28 is
provided beside the table 26. The substrate-holder tilting
mechanism 28 is configured to change the substrate holder 42 from a
vertical position to a horizontal position and place the substrate
holder 42 on the table 26. A substrate W is loaded into and removed
from the substrate holder 42 on the table 26.
[0051] The electroless plating apparatus further includes a
transporter 30 for transporting a substrate W in a horizontal
direction. The transporter 30 includes a fixed base 40 extending
horizontally from a position beside the substrate loader 10 to a
position beside the pretreatment unit 16, an arm 32 configured to
be movable horizontally on the fixed base 40, and a gripper 34
mounted to the arm 32. A linear motor or a rack and pinion may be
used as a driving device for horizontally moving the arm 32. The
gripper 34 is configured to grip the substrate holder 42.
[0052] The substrate holder 42 will now be described with reference
to FIG. 2. FIG. 2 is a diagram showing the substrate holder 42. As
shown in FIG. 2, the substrate holder 42 has out portions 46, 46. A
support arm 45 extends between the projecting portions 46, 46. Two
holding arms 44, 44 for gripping a substrate W are secured to the
support arm 45. The transporter 30 transports the substrate holder
42 with the gripper 34 gripping the support arm 45.
[0053] Each holding arm 44 has a first slit 44a, a second slit 44b,
and a third slit 44c. FIG. 3 shows a substrate W which is held in
the slits 44a to 44c of each holding arm 44. Only one of the
holding arms 44 is shown in FIG. 3. As shown in FIG. 3, the
substrate W is held by the substrate holder 42 with the periphery
of the substrate W inserted into the slits 44a to 44c. As shown in
FIG. 2, the substrate W is slid from a position shown by a dotted
line to a position shown by a solid line, so that the periphery of
the substrate W is inserted into the slits 44a to 44c of the two
holding arms 44, 44. The loading of the substrate W into the
substrate holder 42 is performed by the substrate transport robot
12 shown in FIG. 1 or a substrate slide mechanism (not shown)
provided on the table 26. The second slits 44b may be omitted.
[0054] The electroless plating apparatus includes a
substrate-holder advancing mechanism 50 for advancing the substrate
holder 42 from a holder put-in position "IN" to a holder takeout
position "OUT" while keeping a substrate W immersed in a plating
solution in the first plating bath 20a, and a substrate-holder
advancing mechanism 51 for advancing the substrate holder 42 from a
holder put-in position "IN" to a holder takeout position "OUT"
while keeping the substrate W immersed in a plating solution in the
second plating bath 24a. The holder put-in position "IN" refers to
a position where the substrate holder 42, holding a substrate W, is
put in the plating bath 20a or 20b. The holder takeout position
"OUT" refers to a position where the substrate holder 42, holding a
substrate W, is taken out of the plating bath 20a or 20b. The
substrate-holder advancing mechanisms 50, 51 have the same
construction, and therefore the following description is solely
given of the substrate-holder advancing mechanism 50 and a
description of the substrate-holder advancing mechanism 51 will be
omitted.
[0055] FIG. 4 is a perspective view of the first plating bath 20a
and the substrate-holder advancing mechanism 50. The first plating
bath 20a may be hereinafter referred to simply as plating bath 20a.
As shown in FIG. 4, the substrate-holder advancing mechanism 50 is
disposed adjacent to the plating bath 20a. The substrate-holder
advancing mechanism 50 is configured to move the substrate holder
42 from the holder put-in position "IN" to the holder takeout
position "OUT" in a direction indicated by arrow while keeping a
substrate W immersed in the plating solution held in the first
plating bath 20a.
[0056] The substrate-holder advancing mechanism 50 includes two
fixed supports 59 for supporting a plurality of substrate holders
42 and suspending the substrate holders 42 in the plating bath 20a,
two movable supports 52 for supporting the substrate holders 42,
and two first actuators 53 for moving up and down (or elevating and
lowering) the two movable supports 52, respectively. The two
movable supports 52 are disposed adjacent to the two fixed supports
59, respectively. The fixed supports 59 and the movable supports 52
are configured to support different regions of the projecting
portions 46 of the substrate holder 42.
[0057] The fixed supports 59 are disposed at both sides of the
plating bath 20a. The fixed supports 59 may be secured to both side
walls of the plating bath 20a. A plurality of recesses 59a each for
supporting the projecting portions 46 of the substrate holder 42
are formed in upper surfaces of the fixed supports 59. The recesses
59a of each fixed support 59 are arranged in series along a
direction in which the substrate holders 42 are advanced or
transported in the plating bath 20a. The substrate-holder advancing
mechanism 50 is disposed between lifters 55, 56 and the plating
bath 20a. A plurality of recesses 52a each for supporting the
projecting portions 46 of the substrate holder 42 are formed in
upper surfaces of the movable supports 52. The recesses 52a of each
movable support 52 are arranged in series along a direction in
which the substrate holders 42 are advanced or transported in the
plating bath 20a. The first actuators 53 are coupled to the bottoms
of the movable supports 52, respectively. An air cylinder, for
example, may be used as each of the first actuators 53.
[0058] The substrate-holder advancing mechanism 50 further includes
actuator stands 76 on which the first actuators 53 are fixed, and
second actuators 75 for horizontally moving the movable supports 52
and the first actuators 53. Each second actuator 75 is coupled to
each first actuator 53 via each actuator stand 76. A linear motor
or a combination of a servo motor and a ball screw mechanism, for
example, may be used as each second actuator 75.
[0059] The fixed supports 59 and the movable supports 52 are
disposed parallel to each other. The positions of the fixed
supports 59 are fixed. The movable supports 52 can be moved up and
down by the first actuators 53, and can be moved horizontally by
the second actuators 75. The second actuators 75 extend parallel to
the fixed supports 59 so that the second actuators 75 can move the
movable supports 52 in a direction parallel to the fixed supports
59. Thus, the movable supports 52, the first actuators 53, and the
actuator stands 76 are horizontally moved together by the second
actuators 75.
[0060] The operation of the substrate-holder advancing mechanism 50
will now be described with reference to FIG. 5. In step 1, the
substrate holder 42 is placed on the fixed supports 59 by the
lifter 55 shown in FIG. 1. The projecting portions 46 of the
substrate holder 42 are fitted into the recesses 59a of the fixed
supports 59, so that the substrate holder 42 is suspended in the
plating bath 20a. The substrate holder 42 is now in the holder
put-in position "IN" where the substrate holder 42, holding a
substrate W, is put in the plating bath 20a. While the substrate W
is kept immersed in the plating solution, the substrate holder 42
is advanced from the holder put-in position "IN" to the holder
takeout position "OUT" by the substrate-holder advancing mechanism
50. As described above, the holder takeout position "OUT" is a
position where the substrate holder 42, holding the substrate W, is
removed from the plating bath 20a.
[0061] Next, in step 2, the first actuators 53 raise the movable
supports 52 to insert the projecting portions 46 of the substrate
holder 42 into the recesses 52a of the movable supports 52. The
first actuators 53 further raise the movable supports 52 together
with the substrate holder 42, with its projecting portions 46
supported on the movable supports 52, thereby separating the
substrate holder 42 from the fixed supports 59. In this step 2, the
first actuators 53 elevate the movable supports 52 to a level
higher than the fixed supports 59. The substrate holder 42 is
raised by a distance such that the substrate W in its entirety,
held by the substrate holder 42, is still kept immersed in the
plating solution (i.e., the processing liquid) held in the plating
bath 20a.
[0062] In step 3, while the movable supports 52 are supporting the
substrate holder 42 in the raised position, the second actuators 75
move the movable supports 52 and the substrate holder 42
horizontally by a predetermined distance toward the holder takeout
position "OUT". The substrate W is still kept immersed in the
plating solution during this horizontal movement of the substrate
holder 42. The distance of the horizontal movement of the substrate
holder 42 can be set arbitrarily. In the embodiment illustrated in
FIG. 5, the distance of the horizontal movement of the substrate
holder 42 is equal to a distance between neighboring recesses 59a
of the fixed support 59.
[0063] In step 4, the first actuators 53 lower the movable supports
52 until the projecting portions 46 of the substrate holder 42 are
supported on the fixed supports 59 and the movable supports 52 are
separated from the substrate holder 42. More specifically, the
first actuators 53 lower the movable supports 52 together with the
substrate holder 42 to insert the projecting portions 46 of the
substrate holder 42 into the recesses 59a of the fixed supports 59,
so that the substrate holder 42 is supported by the fixed supports
59 again. The first actuators 53 further lower the movable supports
52, thereby separating the movable supports 52 from the substrate
holder 42. In this step 4, the first actuators 53 lower the movable
supports 52 to a level lower than the fixed supports 59.
[0064] In step 5, after the movable supports 52 are separated from
the substrate holder 42, the second actuators 75 horizontally move
the movable supports 52 by the above-described predetermined
distance toward the holder put-in position "IN". Accordingly, the
movable supports 52 are returned to the initial position shown in
"STEP 1". In step 6, a new substrate holder 42 is transported to
the holder put-in position "IN", and the projecting portions 46 of
the substrate holder 42 are fitted into the recesses 59a of the
fixed supports 59.
[0065] The first actuators 53 and the second actuators 75 repeat
the operations of steps 1 to 5. Consequently, the substrate holder
42 is moved from the holder put-in position "IN" to the holder
takeout position "OUT" while the substrate holder 42 is moved up
and down repeatedly. After the substrate holder 42 has reached the
holder takeout position "OUT", the substrate holder 42 is taken out
of the plating bath 20a by the lifter 56.
[0066] Substrate holders 42 are successively transported into the
plating bath 20a. The substrate holders 42 are put one by one into
the plating bath 20a at the holder put-in position "IN", and
removed one by one from the plating bath 20a at the holder takeout
position "OUT". A plurality of substrate holders 42 constantly
exist in the plating bath 20a, and substrates W, held by the
substrate holders 42, are being plated in the plating solution.
[0067] As can be seen in FIG. 5, as the substrate holder 42 is
moved up and down, the substrate W is also moved up and down while
being kept immersed in the plating solution. Because the surface of
the substrate W moves up and down relative to the plating solution,
the plating solution in contact with the substrate W can be
replaced with a new plating solution. Furthermore, bubbles adhering
to the surface of the substrate W can be removed by the vertical
movement of the substrate W. Therefore, a metal film having a
uniform thickness can be formed on the surface of the substrate
W.
[0068] FIG. 6A is a diagram showing the substrate holder 42 before
it is raised by the first actuators 53, and FIG. 613 is a diagram
showing, the substrate holder 42 after it is raised by the first
actuators 53. In the step 2 illustrated in FIG. 5, the first
actuators 53 raise the movable supports 52 to move the substrate
holder 42 from the position shown in FIG. 6A to the position shown
in FIG. 6B. As shown in FIG. 6B, the substrate W held by the
substrate holder 42 in the raised position remains entirely
immersed in the plating solution.
[0069] In electroless plating of the substrate W, plating of the
substrate W starts when the substrate W is immersed in the plating
solution and terminates when the substrate W is raised from the
plating solution. In this embodiment the substrate W is kept
immersed in the plating solution even when the substrate holder 42
is raised by the first actuators 53. Thus, plating of the substrate
W is not interrupted.
[0070] FIG. 7 is a perspective view of the first plating bath 20a,
the substrate-holder advancing mechanism 50, the lifter 55, and the
lifter 56. As shown in FIG. 7, the lifter 55 and the lifter 56 are
disposed adjacent to the substrate-holder advancing mechanism 50.
The lifter 55 is a unidirectional lifter configured to elevate and
lower the substrate holder 42, while the lifter 56 is a
bidirectional lifter configured to elevate and lower the substrate
holder 42 and horizontally move the substrate holder 42.
[0071] The lifter 55 includes two holder support portions 61 for
supporting the two projecting portions 46 of the substrate holder
42, and two elevators 60 for elevating and lowering the holder
support portions 61 together with the substrate holder 42. The
holder support portions 61 and the elevators 60 are disposed
outside the substrate-holder advancing mechanism 50.
[0072] The lifter 55 is configured to move the substrate holder 42
in the vertical diction so as to transport the substrate holder 42
in the vertical direction between the transporter 30 and the
substrate-holder advancing mechanism 50. More specifically, the
transporter 30 grips the substrate holder 42 with the gripper 34
and transports the substrate holder 42 to the lifter 55. The
elevators 60 of the lifter 55 raise the holder support portions 61
so as to allow the holder support portions 61 to receive the
substrate holder 42 from the transporter 30. After the holder
support portions 61 receive the substrate holder 42, the elevators
60 lower the holder support portions 61 together with the substrate
holder 42 to place the substrate holder 42 on the fixed supports 59
of the substrate-holder advancing mechanism 50 and immerse the
substrate W in the plating solution in the plating bath 20a. The
substrate holder 42 is placed by the lifter 55 on the fixed
supports 59 at the holder put-in position "IN" shown in FIG. 5 (see
"STEP 1"). The lifter 55 receives the substrate holder 42 when the
holder support portions 61 are in the raised positions. After
transferring the substrate holder 42 to the lifter 55, the
transporter 30 can be moved for transporting another substrate
holder 42 holding a substrate W being processed in another
processing bath.
[0073] The lifter 56 includes two holder support portions 63 for
supporting the two projecting portions 46 of the substrate holder
42, two elevators 62 for elevating and lowering the holder support
portions 63 together with the substrate holder 42, and two
horizontal actuators 64 for horizontally moving the holder support
portions 63 and the elevators 62. The holder support portions 63,
the elevators 62, and the horizontal actuators 64 are disposed
outside the substrate-holder advancing mechanism 50.
[0074] The lifter 56 is configured to move the substrate holder 42
in the vertical direction so as to transport the substrate holder
42 in the vertical direction between the substrate-holder advancing
mechanism 50 and the transporter 30. Further, the lifter 56 is
configured to horizontally transport the substrate holder 42
between the two adjacent processing baths (i.e. the plating bath
20a and the rinsing bath 20b). More specifically, the holder
support portions 63 are raised by the elevators 62 to receive the
substrate holder 42 that is placed on the fixed supports 59. The
elevators 62 further raise the holder support portions 63 together
with the substrate holder 42. The holder support portions 63 of the
lifter 56 receive the substrate holder 42 at the holder takeout
position "OUT". The horizontal actuators 64 horizontally move the
holder support portions 63 and the substrate holder 42, which are
in the raised position, to the adjacent processing bath, i.e., the
rinsing bath 20b. The lifter 56 lowers the holder support portions
63 to immerse the substrate W, held by the substrate holder 42, in
the rinsing liquid in the rinsing bath 20b, and elevates the holder
support portions 63 to raise the substrate W from the rinsing
liquid and transfer the substrate holder 42 to the transporter
30.
[0075] As described above, the substrate W held by the substrate
holder 42 is immersed in and raised from the plating solution in
the plating bath 20a and the rising liquid in the rinsing bath 20b
by the lifters 55, 56. The transporter 30 is configured to just
transfer the substrate holder 42 to the lifter 55 and receive the
substrate holder 42 from the lifter 56. The operations of the
lifters 55, 56 to transport the substrate holder 42 can be
performed independently of the operation of the transporter 30.
This can increase the overall throughput of the apparatus.
[0076] The holder support portions 61, 63 of the lifters 55, 56,
the recesses 59a of the fixed supports 59, and the recesses 52a of
the movable supports 52 are arranged so as to support different
regions of the projecting portions 46 of the substrate holder 42.
In particular, as shown in FIG. 2, the holder support portions 61,
63 of the lifters 55, 56 support outer regions 46a of the
projecting portions 46, the recesses 59a of the fixed supports 59
support inner regions 46c of the projecting portions 46, and the
recesses 52a of the movable supports 52 support intermediate
regions 46b each lying between the outer region 46a and the inner
region 46c.
[0077] The operation of the electroless plating apparatus will now
be described with reference to FIG. 1. First, the substrate holder
42 in a vertical position is taken out of the storage bath 14 by a
lifter 80 disposed adjacent to the storage bath 14. The lifter 80
is a bidirectional lifter configured to elevate and lower the
substrate holder 42 and horizontally move the substrate holder 42.
The lifter 80 has the same construction as the above-described
lifter 56 shown in FIG. 7, and therefore a detailed description
thereof is omitted. The lifter 80 can take out any substrate holder
42 from a number of substrate holders 42 arranged in the storage
bath 14. The lifter 80 transfers the substrate holder 42 to the
transporter 30, and the transporter 30 transfers the substrate
holder 42 to the substrate-holder tiling mechanism 28 of the
substrate loader 10. The substrate-holder tilting mechanism 28 of
the substrate loader 10 changes the substrate holder 42 from a
vertical position to a horizontal position, and places the
substrate holder 42 on the table 26.
[0078] The substrate transport robot 12 takes one substrate W out
of the wafer cassette mounted on one of the loading ports 2, and
places the substrate W on the aligner 4. The aligner 4 aligns an
orientation flat or a notch in a predetermined direction.
Thereafter, the substrate transport robot 12 removed the substrate
W from the aligner 4, and inserts the substrate W into the
substrate holder 42 on the table 26. More specifically, the
substrate transport robot 12 loads the substrate W into the
substrate holder 42 by sliding the substrate W from the position
shown by the dotted line in FIG. 2 to the position shown by the
solid line. Instead, a substrate slide mechanism (not shown) for
sliding the substrate W parallel to the table 26 may be provided.
In that case, the substrate transport robot 12 transfers the
substrate W to the substrate slide mechanism, which then loads the
substrate W into the substrate holder 42.
[0079] Next, the substrate-holder tilting mechanism 28 changes the
substrate holder 42 from the horizontal position to the vertical
position. The gripper 34 of the arm 32 grips the substrate holder
42 in the upright position, and the transporter 30 moves the
substrate holder 42 to a predetermined position above the
pretreatment bath 16a. A lifter 81 is provided adjacent to the
pretreatment bath 16a. The lifter 81 is a bidirectional lifter
configured to elevate and lower the substrate holder 42 and
horizontally move the substrate holder 42. The lifter 81 has the
same construction as the above-described lifter 56 shown in FIG. 7,
and therefore a detailed description thereof is omitted.
[0080] The lifter 81 receives the substrate holder 42 from the
transporter 30, and lowers the substrate holder 42 to immerse the
substrate W, held by the substrate holder 42, in a pretreatment
solution in the pretreatment bath 16a. The surface of the substrate
W is pretreated with the pretreatment solution. This pretreatment
is, for example, a process of removing a copper oxide layer formed
on the surface of the substrate W. After the pretreatment, the
lifter 81 elevates the substrate holder 42 to raise the substrate W
from the pretreatment solution.
[0081] The lifter 81 horizontally moves the substrate holder 42 to
the rinsing bath 16b adjacent to the pretreatment bath 16a, and
lowers the substrate holder 42 to immerse the substrate W in a
rinsing liquid in the rinsing bath 16b. The substrate W is rinsed
with the rinsing liquid. After the rinsing, the lifter 81 elevates
the substrate holder 42 to raise the substrate W from the rinsing
liquid in the rinsing bath 16b.
[0082] The transporter 30 receives the substrate holder 42 from the
lifter 81, and moves the substrate holder 42 to a predetermined
position above the nuclei forming bath 18a. A lifter 82 is provided
adjacent to the nuclei forming bath 18a. The lifter 82 is a
bidirectional lifter configured to elevate and lower the substrate
holder 42 and horizontally move the substrate holder 42. The litter
82 has the same construction as the above-described lifter 56 shown
in FIG. 7, and therefore a detailed description thereof is
omitted.
[0083] The lifter 82 receives the substrate holder 42 from the
transporter 30, and lowers the substrate holder 42 to place the
substrate W, held by the substrate holder 42, in the nuclei forming
bath 18a. In the nuclei forming bath 18a, nuclei (e.g., palladium
nuclei) necessary for deposition of a metal film are formed on the
surface of the substrate W. Thereafter, the lifter 82 elevates the
substrate holder 42 to raise the substrate W from the nuclei
forming bath 18a. The lifter 82 then horizontally moves the
substrate holder 42 to the rinsing bath 18b adjacent to the nuclei
forming bath 18a, and lowers the substrate holder 42 to immerse the
substrate W in a rinsing liquid in the rinsing bath 18b. The
substrate W is rinsed with the rinsing liquid. After the rinsing,
the lifter 82 elevates the substrate holder 42 to raise the
substrate W from the rinsing liquid in the rinsing bath 18b.
[0084] The transporter 30 receives the substrate holder 42 from the
lifter 82, and moves the substrate holder 42 to a predetermined
position above the plating bath 20a. The lifter 55 receives the
substrate holder 42 from the transporter 30, and lowers the
substrate holder 42 to place it on the substrate-holder advancing
mechanism 50 in the above-described manner. The substrate holder 42
is placed in the above-described holder put-in position "IN". As
illustrated in FIG. 5, the substrate-holder advancing mechanism 50
advances the substrate holder 42 from the holder put-in position
"IN" to the holder takeout position "OUT" while keeping the
substrate W in its entirety immersed in the plating solution held
in the plating bath 20a and moving up and down the substrate holder
42 repeatedly. While the substrate W thus moves in the plating
solution, first-step electroless plating is performed on the
surface of the substrate W. The first-step electroless plating is,
for example, cobalt (Co) plating.
[0085] After a predetermined time has elapsed since the substrate W
was immersed in the plating solution, a subsequent substrate holder
42 holding another substrate is put in the plating bath 20a at the
holder put-in position "IN". Thus, substrate holders 42 are
successively put in the plating bath 20a at predetermined time
intervals, and successively removed from the plating bath 20a at
the predetermined time intervals.
[0086] The lifter 56 elevates the substrate holder 42 that has
reached the holder takeout position "OUT" to raise the substrate W
from the plating solution. The lifter 56 then horizontally moves
the substrate holder 42 to the rinsing bath 20b adjacent to the
plating bath 20a, and lowers the substrate holder 42 to immerse the
substrate W in a rinsing liquid in the rinsing bath 20b. The
substrate W is rinsed with the rinsing liquid. After the rinsing,
the lifter 56 elevates the substrate holder 42 to raise the
substrate W from the rinsing liquid in the rinsing bath 20b.
[0087] The transporter 30 receives the substrate holder 42 from the
lifter 56, and horizontally moves the substrate holder 42 to a
predetermined position above the second plating bath 24a. A lifter
83, a lifter 84, and the substrate-holder advancing mechanism 51
are provided adjacent to the plating bath 24a. The lifter 83 is a
unidirectional lifter configured to elevate and lower the substrate
holder 42, while the lifter 84 is a bidirectional lifter configured
to elevate and lower the substrate holder 42 and horizontally move
the substrate holder 42. The lifter 83 and the lifter 84 have the
same constructions as the above-described lifter 55 and lifter 56,
respectively.
[0088] The lifter 83 receives the substrate holder 42 from the
transporter 30, and lowers the substrate holder 42 to place it on
the substrate-holder advancing mechanism 51. The substrate holder
42 is placed at the above-described holder put-in position "IN". As
with the substrate-holder advancing mechanism 50, the
substrate-holder advancing mechanism 51 advances the substrate
holder 42 from the holder put-in position "IN" to the holder
takeout position "OUT" while keeping the substrate W in its
entirety immersed in the plating solution in the plating bath 24a
and moving up and down the substrate holder 42 repeatedly. While
the substrate W thus moves in the plating solution, second-step
electroless plating is performed on the surface of the substrate W.
The second-step electroless plating is, for example, gold (Au)
plating.
[0089] After a predetermined time has elapsed since the substrate W
was immersed in the plating solution, a subsequent substrate holder
42 holding another substrate is put in the plating bath 24a at the
holder put-in position "IN". Thus, substrate holders 42 are
successively put in the plating bath 24a at predetermined time
intervals, and successively taken out of the plating bath 24a at
the predetermined time intervals.
[0090] The lifter 84 elevates the substrate holder 42 that has
reached the holder takeout position "OUT" to raise the substrate W
from the plating solution. The lifter 84 then horizontally moves
the substrate holder 42 to the rinsing bath 24b adjacent to the
plating bath 24a, and lowers the substrate holder 42 to immerse the
substrate W in a rinsing liquid in the rinsing bath 24b. The
substrate W is rinsed with the rinsing liquid. After the rinsing,
the lifter 84 elevates the substrate holder 42 to raise the
substrate W from the rinsing liquid in the rinsing bath 24b.
[0091] The transporter 30 receives the substrate holder 42 from the
lifter 84, horizontally moves the substrate holder 42, and
transfers the substrate holder 42 to the substrate-holder tilting
mechanism 28. The substrate-holder tilting mechanism 28 changes the
substrate holder 42 from the vertical position to the horizontal
position, and places the substrate holder 42 on the table 26. The
substrate transport robot 12 removes the substrate W from the
substrate holder 42 by sliding the substrate W from the position
shown by the solid line in FIG. 2 to the position shown by the
dotted line. Instead, it is possible to slide the substrate W from
the solid-line position in the substrate holder 42 by means of a
substrate slide mechanism (not shown) provided in the table 26, and
then take the substrate W out of the substrate slide mechanism by
means of the substrate transport robot 12.
[0092] Thereafter, the substrate transport robot 12 transports the
substrate W to the spin-rinse-dryer 6. The spin-rinse-dryer 6 dries
the substrate W by rotating it at a high speed. The substrate
transport robot 12 removes the dried substrate W from the
spin-rinse-dryer 6 and returns it to the wafer cassette on the
loading port 2, thereby completing the sequence of processing steps
for the substrate W.
[0093] Other embodiments will now be described with reference to
the drawings. 9 is a schematic plan view of en electroless plating
apparatus according to another embodiment. As shown in FIG. 9, the
plating apparatus includes a frame 201, loading ports 202 on which
wafer cassettes, each housing substrates W (e.g., as wafers)
therein, are placed, a controller 203 for controlling operation of
the plating apparatus, and an aligner 204 for aligning an
orientation flat or a notch of a substrate W in a predetermined
direction. The plating apparatus further includes a
spin-rinse-dryer (SRD) 206 for drying a plated substrate W by
rotating it at a high speed, substrate loaders 210 each for loading
a substrate W to be plated into a substrate holder 242 (which will
be described later) and removing a plated substrate W from the
substrate holder 242, and a substrate transport robot 212 for
transporting a substrate W.
[0094] A travel mechanism 205 is installed along an arrangement
direction of the loading ports 202. The substrate transport robot
212 is installed on the travel mechanism 205. The substrate
transport robot 212 moves on the travel mechanism 205 and accesses
the wafer cassette set on one of the loading ports 202, takes a
substrate W to be plated out of the wafer cassette, and transfers
the substrate W to the substrate holder 242 in one of the substrate
loaders 210. The aligner 204, the spin-rinse-dryer 206, the
substrate loaders 210, and the substrate transport robot 212 are
disposed in the frame 201.
[0095] In the frame 201, there are disposed a plurality of
processing baths 229 for performing plating and associated
processing of a substrate W, and a transporter (or a substrate
holder transporter) 230 for transporting a substrate W. The
transporter 230 has an arm 232 provided with a gripper 234. The
transporter 230 is configured to be capable of transporting the
substrate holder 242, holding a substrate W, between one of the
substrate loaders 210 and the processing baths 229, and vertically
moving the substrate holder 242 together with the substrate W.
[0096] The processing baths 229 are arranged in series, and the
transporter 230 is disposed along an arrangement direction of the
processing baths 229. The processing baths 229 and the transporter
230 constitute a plating section 231. The plating apparatus
according to this embodiment includes two plating sections 231, 231
disposed in parallel. The plating sections 231, 231 are electroless
plating sections for plating a surface of a substrate W with metal
without passing an electric current through a plating solution.
However, the plating sections 231, 231 may be electroplating
sections for plating a surface of a substrate W with metal by
passing an electric current through a plating solution.
[0097] The processing baths 229 of each plating section 231 include
a storage bath 214 for storing substrate holders 242, a
pretreatment bath 260 for pretreating a substrate W with a
pretreatment solution, a rinsing bath 262 for rinsing the substrate
W with a processing liquid (pure water) after the pretreatment of
the substrate W, a nuclei forming bath 264 for forming e.g.,
palladium nuclei on the surface of the substrate W, and a rinsing
bath 266 for rinsing the substrate W, which has been immersed in
the processing liquid in the nuclei forming bath 264, with a
processing liquid (pure water). The processing baths 229 further
include a first plating bath 26g for forming e.g., a cobalt (Co)
layer or a nickel (Ni) layer on the surface of the substrate W by
electroless plating, a rinsing bath 270 for rinsing the substrate
W, which has been immersed in a plating solution in the first
plating bath 268, with a processing liquid (pure water), a second
plating bath 272 for forming e.g., a gold (Au) layer on the surface
of the substrate W by electroless plating, a rinsing bath 274 for
rinsing the substrate W, which has been immersed in a plating
solution in the second plating bath 272, with a processing liquid
(pure water), and a blow bath 275 for drying the rinsed substrate
W. The first plating bath 268 is constituted by a plurality of
plating cells 268a. The pretreatment bath 260, the rinsing bath
262, the nuclei forming bath 264, the rinsing bath 266, the first
plating bath 268, the rinsing bath 270, the second plating bath
272, the rinsing bath 274, the blow bath 275 and the storage bath
214 are arranged in series in this order.
[0098] The pretreatment bath 260, the nuclei forming bath 264, the
first plating bath 268, the second plating bath 272, and the
rinsing baths 262, 266, 270, 274 are each a processing bath having
a rectangular cross-sectional shape, capable of holding a
processing liquid and provided with an overflow bath (not shown).
The processing liquid that has overflown each processing bath
circulates through a circulation line by means of a pump and
resupplied to the processing bath. Each circulation line is
provided with a filter and a processing solution temperature
regulator.
[0099] Two chemical supply units 290, 290 for supplying liquid
chemicals, including a plating solution, necessary for plating or
associated processing of a substrate W, are disposed adjacent to
ends of the plating sections 231, 231. A substrate transfer section
302 is disposed adjacent to the other ends of the plating sections
231, 231. The substrate transfer section 302 includes two substrate
loaders 210, 210, two spin-rinse-dryers 206, one aligner 204, one
travel mechanism 205 and one substrate transport robot 212. The two
spin-rinse-dryers 206 are stacked on top of each other, and
therefore one spin-rinse-dryer 206 is shown in FIG. 9.
[0100] The substrate loaders 210 are disposed adjacent to the
storage baths 214. Each substrate loader 210 includes a table 280
on which a substrate holder 242 is placed in a horizontal position,
and a substrate-holder tilting mechanism 282 for standing and
leaning the substrate holder 242. The substrate-holder tilting
mechanism 282 is provided beside the table 280. The
substrate-holder tilting mechanism 282 is configured to change the
substrate holder 242 from a vertical position to a horizontal
position and place the substrate holder 242 on the table 280.
[0101] The travel mechanism 205 is installed between the loading
ports 202 and the spin-rinse-dryers 206 along the arrangement
direction of the loading ports 202. The substrate transport robot
212 is installed on the travel mechanism 205. The aligner 204 is
disposed adjacent to the travel mechanism 205.
[0102] Each transporter 230 includes a fixed base 240 secured to
the frame 201 and extending horizontally from a position beside the
substrate loader 210 to a position beside the pretreatment bath
260, a lifter 233 configured to be horizontally movable on the
fixed base 240, and an arm 232 coupled to the lifter 233. The arm
232 and the lifter 233 horizontally move together, and the arm 232
is elevated and lowered by the lifter 233. A linear motor or a rack
and pinion may be used as a driving device for horizontally moving
the lifter 233 and the arm 232. The arm 232 has a gripper 234 which
is configured to grip one substrate holder 242.
[0103] The substrate holder 242 will now be described with
reference to FIG. 10, FIG. 10 is a diagram showing the substrate
holder 241. As shown in FIG. 10, the substrate holder 242 includes
holding arms 241, 244 for gripping a substrate W, and a support
member 246 for supporting the holding arms 244, 244. Each holding
arm 24 has a first slit 244a, a second slit 244b, and a third slit
244c. FIG. 11 shows a substrate W which is held in the slits 244a
to 244c of each holding arm 244. Only one of the holding arms 244
is shown in FIG. 11. As shown in FIG. 11, the substrate W is held
by the substrate holder 242 with a periphery of the substrate W
inserted into the slits 244a to 244c. As shown in FIG. 10, the
periphery of the substrate W is inserted into the slits 244a to
244c of the two holding arms 244, 244 by sliding the substrate W
from a position shown by a dotted line to a position shown by a
solid line by the substrate transport robot 212 or a substrate
slide mechanism (not shown) provided on the table 280.
[0104] The layout of the electroless plating apparatus according to
this embodiment in the frame 201 will now be described with
reference to FIG. 9. As shown in FIG. 9, the electroless plating
apparatus according to this embodiment includes two plating
sections (electroless plating sections) 231, 231 which are disposed
in parallel with a distance from each other in the frame 201. A
maintenance space 300, from which an operator can access any
component of the plating apparatus, is provided between the plating
sections 231, 231. The shaded area in FIG. 9 represents the
maintenance space 300. The maintenance space 300 extends parallel
to the transporters 230, 230 and are disposed adjacent to the
transporters 230, 230, so that an operator can easily reach the
transporters 230, 230 and can easily perform maintenance work on
the transporters 230, 230. Part of the maintenance space 300 lies
between the chemical supply units 290, 290.
[0105] The plating sections 231, 231 are disposed on both sides of
the maintenance space 300 so that an operator can quickly view both
of the plating sections 231, 231 from the maintenance space 300.
Further, the plating apparatus having the two plating sections 231,
231 can be operated with various plating conditions. For example,
it is possible to stop the operation of one plating section 231 and
perform maintenance work on the plating section 231, while
operating the other plating section 231. Further, it is possible to
use different processing liquids and perform different plating
processes in the plating sections 231, 231.
[0106] The spin-rinse-dryer 206 is disposed between the substrate
loaders 210, 210 and adjacent to the end of the maintenance space
300, so that an operator can easily access the spin-rinse-dryer 206
and can easily perform maintenance work on the spin-rinse-dryer
206.
[0107] FIG. 12 is a diagram showing the electroless plating
apparatus of FIG. 9 as viewed in the direction of arrow A. As shown
in FIG. 12, filters 304 which do not permit passage of unwanted
matter contained in a processing liquid and filter boxes 305 for
housing the filters 304 therein are disposed on an upper area of
the exterior wall of the frame 201. It is common practice in
conventional plating apparatuses to dispose the filters 304 on a
lower area of the exterior wall of the frame 201. This requires
considerable effort for work to repair or replace the filters 304.
In contrast, because the filters 304 are disposed on an upper area
of the exterior wall of the frame 201 in the plating apparatus
according to this embodiment, an operator can easily reach the
filters 304. This enables the operator to easily perform
maintenance work (such as repair or replacement) on the filters
304.
[0108] FIG. 13 is a schematic cross-sectional view taken along line
B-B of FIG. 9. In FIG. 13, the chemical supply units 290 are shown
schematically for a better understanding of the drawing. As shown
in FIG. 13, a platform 300a as a foothold for an operator and
support legs 300b, 300b for supporting the platform 300a are
provided between the plating sections 231, 231. The maintenance
space 300 is formed over the platform 300a, while a piping space
306 is formed under the platform 300a. Pipes for conveying
processing liquids for use in plating or associated processing are
concentrated in the piping space 306. The pipes are coupled e.g.,
to the filters 304 and/or the chemical supply units 290, 290.
[0109] Utility fluid introduction ports (or joints) 308 for
receiving a utility fluid (e.g., pure water or nitrogen gas), which
is necessary for the operation of the electroless plating
apparatus, from a utility supply facility and for supplying the
fluid to the plating sections 231, 231 may be provided under the
platform 300a (in the piping space 306). The utility fluid may be
supplied through a pipe from below the floor on which the plating
apparatus is installed, as shown in FIG. 13.
[0110] According to this embodiment, an operator can easily view
the interior of each of the processing baths 229 from the
maintenance space 300 provided between the plating sections 231,
231. Because the filters 304 and the filter boxes 305 are disposed
on the upper area of the exterior wall of the plating apparatus,
replacement of the filters 304 can be performed from the outside of
the plating apparatus. Because the filter boxes 305 are provided on
the upper area of the exterior wall of the plating apparatus, a
certain limitation is placed on maintenance work on the interior of
the plating apparatus when the maintenance work is performed from
the outside of the apparatus. However, since the maintenance space
300 is provided, an operator can perform easy maintenance work on
the interior of the plating apparatus. In addition, providing the
piping space 306 under the maintenance space 300 can improve
efficient use of the space.
[0111] The operation of the plating apparatus having the above
construction will now be described. First, the substrate holder 242
in a vertical position is taken from one of the storage baths 214
by the arm 232 of the transporter 230. The arm 232 holding the
substrate holder 242 moves horizontally and transfers the substrate
holder 242 to the substrate loader 210. The substrate-holder
tilting mechanism 282 of the substrate loader 210 changes the
substrate holder 242 from the vertical position to the horizontal
position, and places the substrate holder 242 on the table 280.
[0112] The substrate transport robot 212 takes one substrate W from
the cassette mounted on one of the loading ports 202, and places
the substrate W on the aligner 204. The aligner 204 aligns an
orientation flat or a notch in a predetermined direction.
Thereafter, the substrate transport robot 212 removes the substrate
W from the aligner 204, and inserts the substrate W into the
substrate holder 242 on the table 280. More specifically, the
substrate transport robot 212 horizontally moves the substrate W to
a predetermined position, and loads the substrate W into the
substrate holder 242 by sliding the substrate W from the position
shown by the dotted line in FIG. 10 to the position shown by the
solid line so as to insert the substrate W into the slits 244a to
244c. Instead, a substrate slide mechanism (not shown) for sliding
the substrate W parallel to the table 280 may be provided. In that
case, the substrate transport robot 212 transfers the substrate W
to the substrate slide mechanism, which loads the substrate W into
the substrate holder 242.
[0113] Next, the substrate-holder tilting mechanism 282 changes the
substrate holder 242 from the horizontal position to the vertical
position. The gripper 234 of the arm 232 grips the substrate holder
242 in the upright position, and the transporter 230 horizontally
moves the substrate W and the substrate holder 242 to a
predetermined position above the pretreatment bath 260. The lifter
233 lowers the atm 232 to immerse the substrate W and the substrate
holder 242 in a processing liquid in the pretreatment bath 260,
thereby cleaning the surface of the substrate W. After the
pretreatment of the substrate W, the lifter 233 elevates the arm
232 to raise the substrate W and the substrate holder 242 from the
processing liquid in the pretreatment bath 260.
[0114] Next, the arm 232 moves the substrate holder 242 to a
predetermined position above the rinsing bath 262. The lifter 233
lowers the arm 232 to immerse the substrate W and the substrate
holder 242 in a processing liquid (typically pure water) in the
rinsing bath 262, thereby rinsing the surfaces of the substrate W
and the substrate holder 242. After the rinsing of the substrate W,
the lifter 233 elevates the arm 232 to raise the substrate W and
the substrate holder 242 from the processing liquid in the rinsing
bath 262.
[0115] Next, the arm 232 moves the substrate holder 242 to a
predetermined position above the nuclei forming bath 264. The
lifter 233 lowers the arm 232 to immerse the substrate W and the
substrate holder 242 in a processing liquid in the nuclei forming
bath 264, thereby forming e.g., palladium nuclei (palladium
catalyst) on the surface of the substrate W. Thereafter, the lifter
233 elevates the arm 232 to raise the substrate W and the substrate
holder 242 from the processing liquid in the nuclei forming bath
264.
[0116] Next, the arm 232 moves the substrate holder 242 to a
predetermined position above the rinsing bath 266. The lifter 233
lowers the arm 232 to immerse the substrate W and the substrate
holder 242 in a processing liquid (typically pure water) in the
rinsing bath 266, thereby rinsing the surfaces of the substrate W
and the substrate holder 242. Thereafter, the lifter 233 elevates
the arm 232 to raise the substrate W and the substrate holder 242
from the processing liquid in the rinsing bath 266.
[0117] Next, the arm 232 moves the substrate holder 242 to a
predetermined position above the first plating bath 268. The lifter
233 lowers the arm 232 to immerse the substrate W and the substrate
holder 242 in a plating solution (processing liquid) held in one of
the plating cells 268a of the first plating bath 268, thereby
electroless-plating the surface of the substrate V e.g., with
cobalt (Co) or nickel (Ni). The same operation is repeated for a
plurality of substrates W to immerse the substrates W in the
plating solution (processing liquid) in all the plating cells 268a.
After the elapse of a predetermined plating time the transporter
230 raises substrate holders 242, holding the substrates W, one by
one from the plating solution in the first plating bath 268.
[0118] Next, the arm 232 of the transporter 230 moves the substrate
holder 242 to a predetermined position above the rinsing bath 270.
The lifter 233 lowers the arm 232 to immerse the substrate W and
the substrate holder 242 in a processing liquid (typically pure
water) in the rinsing bath 270, thereby rinsing the surfaces of the
substrate W and the substrate holder 242. Thereafter, the lifter
233 elevates the arm 232 to raise the substrate W and the substrate
holder 242 from the processing liquid in the rinsing bath 270.
[0119] Next, the arm 232 moves the substrate holder 242 to a
predetermined position above the second plating bath 272. The
lifter 233 lowers the arm 232 to immerse the substrate W and the
substrate holder 242 in a plating solution (processing liquid) in
the second plating bath 272, thereby forming a gold (Au) layer on
the peace of the substrate W by electroless plating. Thereafter,
the lifter 233 elevates the arm 232 to raise the substrate W and
the substrate holder 242 from the plating solution in the second
plating bath 272.
[0120] Next, the arm 232 moves the substrate W and the substrate
holder 242 to a predetermined position above the rinsing bath 274.
The lifter 233 lowers the arm 232 to immerse the substrate W and
the substrate holder 242 in a processing liquid (typically pure
water) in the rinsing bath 274, thereby rinsing the surface of the
substrate W. Thereafter, the lifter 233 elevates the arm 232 to
raise the substrate W and the substrate holder 242 from the
processing liquid in the rinsing bath 274.
[0121] After the plating of the substrate W, the arm 232
horizontally moves the substrate W and the substrate holder 242 to
a position above the blow bath 275. The lifter 233 lowers the arm
232 to set the substrate W and the substrate holder 242 at a
predetermined position in the blow bath 275. The blow bath 275
generates flow of air or an inert gas (e.g., N.sub.2) blowing onto
the surfaces of the substrate holder 242 and the substrate W held
by the substrate holder 242 to remove liquid droplets from the
substrate holder 242 and the substrate W, thereby drying the
substrate holder 242 and the substrate W. After completion of the
gas blowing, the gripper 234 of the arm 232 grips the substrate
holder 242, and the lifter 233 elevates the arm 232 to raise the
substrate holder 242 from the blow bath 275.
[0122] The arm 232 moves horizontally and transfers the substrate
holder 242 to the substrate-holder tilting mechanism 282. The
substrate-holder tilting mechanism 28 turns the substrate holder
282 from the vertical position to the horizontal position, and
places the substrate holder 242 on the table 280. The substrate
transport robot 212 removes the substrate W from the substrate
holder 242 by sliding the substrate W from the position shown by
the solid line in FIG. 10 to the position shown by the dotted line.
Instead, it is possible to slide the substrate W from the
solid-line position in the substrate holder 242 by means of a
substrate slide mechanism (not shown) provided in the table 280,
and then take the substrate W out of the substrate slide mechanism
by means of the substrate transport robot 212. Thereafter, the
substrate transport robot 212 transports the substrate W to the
spin-rinse-dryer 206. The spin-rinse-dryer 206 dries the substrate
W by rotating it at a high speed. The substrate transport robot 212
removes the dried substrate W from the spin-rinse-dryer 206 and
returns it to the cassette on the loading port 202, thereby
completing the sequence of processing steps for the one
substrate.
[0123] FIG. 14 is a schematic plan view of an electroless plating
apparatus according to yet another embodiment. The processing baths
229 of this embodiment are the same as the processing baths 229 of
the preceding embodiment shown in FIG. 9, and are therefore
illustrated in a simplified manner in FIG. 14. The shaded area in
FIG. 14 represents a maintenance space 300. The plating apparatus
shown in FIG. 14 differs from the plating apparatus shown in FIG. 9
in that the spin-rinse-dryers 206 (one of which is shown in FIG.
14) and the substrate loaders 210, 210 are disposed adjacent to the
maintenance space 300. Owing to such a layout according to this
embodiment, an operator can easily access the spin-rinse-dryers 206
and the substrate loaders 210, 210 and easily perform maintenance
work on them. In this embodiment the transporters 230, 230 of the
plating sections 231, 231 are not disposed adjacent to the
maintenance space 300. However, it is possible to dispose the
transporters 230, 230 adjacent to the maintenance space 300 as
shown in FIG. 9.
[0124] In the above-described two embodiments, the lifter 233 of
each transporter 230 horizontally and vertically moves the
substrate holder 242. Instead, it is possible to provide lifters
separately from the transporters 230. In that case, a plurality of
lifters are provided adjacent to each processing bath 229, and each
transporter 230 is configured to move the arm 232 only
horizontally.
[0125] While the present invention has been described with
reference to preferred embodiments, it is understood that the
present invention is not limited to the embodiments described
above, but is capable of various changes and modifications within
the scope of the inventive concept as expressed herein. For
example, although in the above-described embodiments the
maintenance space 300 is provided in the electroless plating
apparatus, the maintenance space 300 may be provided in an
electroplating apparatus. Providing the maintenance space 300 in an
electroplating apparatus can also achieve the same advantageous
effects as described above.
* * * * *