U.S. patent application number 11/109720 was filed with the patent office on 2005-10-27 for substrate processing apparatus.
Invention is credited to Hodai, Masao, Kanda, Hiroyuki, Katsuoka, Seiji, Matsuda, Naoki, Mishima, Koji, Nomura, Kazufumi, Suzuki, Hidenao.
Application Number | 20050236268 11/109720 |
Document ID | / |
Family ID | 35135335 |
Filed Date | 2005-10-27 |
United States Patent
Application |
20050236268 |
Kind Code |
A1 |
Mishima, Koji ; et
al. |
October 27, 2005 |
Substrate processing apparatus
Abstract
A substrate processing apparatus has a plating apparatus
configured to plate a substrate to deposit a metal on a surface of
the substrate and an additional process apparatus configured to
perform an additional process on the substrate. The plating
apparatus has a substrate placement stage on which the substrate to
be transferred to the additional process apparatus is placed. The
additional process apparatus has an additional process unit
configured to perform the additional process on the substrate and a
substrate transfer device operable to transfer the substrate
between the substrate placement stage of the plating apparatus and
the additional process unit. The substrate processing apparatus can
perform an additional process in addition to a plating process
without lowering a throughput of the apparatus and can upgrade the
additional process at a low cost.
Inventors: |
Mishima, Koji; (Tokyo,
JP) ; Kanda, Hiroyuki; (Tokyo, JP) ; Katsuoka,
Seiji; (Tokyo, JP) ; Hodai, Masao; (Tokyo,
JP) ; Suzuki, Hidenao; (Tokyo, JP) ; Nomura,
Kazufumi; (Tokyo, JP) ; Matsuda, Naoki;
(Tokyo, JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
35135335 |
Appl. No.: |
11/109720 |
Filed: |
April 20, 2005 |
Current U.S.
Class: |
204/198 ;
204/228.7; 257/E21.175; 257/E21.585 |
Current CPC
Class: |
C23C 18/1632 20130101;
H01L 21/2885 20130101; H01L 21/67161 20130101; H01L 21/76877
20130101; C25D 21/04 20130101; C25D 17/001 20130101; H01L 21/6723
20130101; C25D 5/48 20130101; C25D 7/123 20130101; H01L 21/67017
20130101; H01L 21/67219 20130101; C25D 5/50 20130101 |
Class at
Publication: |
204/198 ;
204/228.7 |
International
Class: |
C25D 017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 21, 2004 |
JP |
2004-125920 |
May 13, 2004 |
JP |
2004-143375 |
Claims
What is claimed is:
1. A substrate processing apparatus comprising: a plating apparatus
configured to plate a substrate so as to deposit a metal on a
surface of the substrate; and an additional process apparatus
configured to perform an additional process on the substrate,
wherein said plating apparatus comprises a substrate placement
stage on which the substrate to be transferred to said additional
process apparatus is placed, wherein said additional process
apparatus comprises: an additional process unit configured to
perform the additional process on the substrate; and a substrate
transfer device operable to transfer the substrate between said
substrate placement stage of said plating apparatus and said
additional process unit.
2. The substrate processing apparatus as recited in claim 1,
wherein said plating apparatus and said additional process
apparatus are disposed independently of each other.
3. The substrate processing apparatus as recited in claim 1,
wherein said additional process unit comprises an annealing unit
configured to heat the substrate.
4. The substrate processing apparatus as recited in claim 1,
wherein said additional process unit comprises a cleaning unit
configured to clean the substrate.
5. The substrate processing apparatus as recited in claim 1,
wherein said additional process unit comprises an etching unit
configured to etch the substrate.
6. The substrate processing apparatus as recited in claim 1,
wherein said additional process unit comprises a polishing unit
configured to polish the substrate.
7. The substrate processing apparatus as recited in claim 1,
wherein said additional process unit comprises a film thickness
measurement unit configured to measure a film thickness of the
metal film formed on the surface of the substrate.
8. The substrate processing apparatus as recited in claim 1,
wherein said plating apparatus is configured to fill fine recesses
formed in the substrate with the metal.
9. The substrate processing apparatus as recited in claim 1,
wherein the metal contains at least one of copper, cobalt, nickel,
gold, and tin.
10. A substrate processing apparatus comprising: a plating
apparatus configured to plate a substrate; and an additional
process apparatus configured to perform an additional process on
the substrate, said additional process apparatus being disposed
adjacent to said plating apparatus, wherein said plating apparatus
comprises: a plating unit configured to plate the substrate so as
to deposit a metal on a surface of the substrate; a first substrate
transfer device operable to transfer the substrate in said plating
apparatus; and a substrate placement stage on which the substrate
to be transferred to said additional process apparatus is placed,
wherein said additional process apparatus comprises: an additional
process unit configured to perform the additional process on the
substrate; and a second substrate transfer device operable to
transfer the substrate between said substrate placement stage of
said plating apparatus and said additional process unit.
11. The substrate processing apparatus as recited in claim 10,
wherein said plating apparatus and said additional process
apparatus are disposed independently of each other.
12. The substrate processing apparatus as recited in claim 10,
wherein said additional process unit comprises an annealing unit
configured to heat the substrate.
13. The substrate processing apparatus as recited in claim 10,
wherein said additional process unit comprises a cleaning unit
configured to clean the substrate.
14. The substrate processing apparatus as recited in claim 10,
wherein said additional process unit comprises an etching unit
configured to etch the substrate.
15. The substrate processing apparatus as recited in claim 10,
wherein said additional process unit comprises a polishing unit
configured to polish the substrate.
16. The substrate processing apparatus as recited in claim 10,
wherein said additional process unit comprises a film thickness
measurement unit configured to measure a film thickness of the
metal film formed on the surface of the substrate.
17. The substrate processing apparatus as recited in claim 10,
wherein said plating apparatus is configured to fill fine recesses
formed in the substrate with the metal.
18. The substrate processing apparatus as recited in claim 10,
wherein the metal contains at least one of copper, cobalt, nickel,
gold, and tin.
19. A substrate processing apparatus comprising: a main process
apparatus configured to perform a main process on a substrate; and
an additional process apparatus configured to perform an additional
process on the substrate, wherein said main process apparatus
comprises a substrate placement stage on which the substrate to be
transferred to said additional process apparatus is placed, wherein
said additional process apparatus comprises: an additional process
unit configured to perform the additional process on the substrate;
and a substrate transfer device operable to transfer the substrate
between said substrate placement stage of said main process
apparatus and said additional process unit.
20. A substrate processing apparatus comprising: a plating unit
configured to plate a substrate so as to deposit a metal on a
surface of the substrate; a cleaning and drying unit configured to
clean and dry the substrate; a substrate transfer device operable
to transfer the substrate between said plating unit and said
cleaning and drying unit; an air supply system configured to supply
at least one of intake air and circulation air into said substrate
processing apparatus; and a volatile substance removal mechanism
configured to remove a volatile substance contained in the at least
one of intake air and circulation air to be supplied by said air
supply system.
21. The substrate processing apparatus as recited in claim 20,
wherein said volatile substance removal mechanism comprises a
chemical filter capable of removing the volatile substance
contained in the at least one of intake air and circulation
air.
22. The substrate processing apparatus as recited in claim 21,
wherein said chemical filter is provided at an upper portion of
said substrate processing apparatus.
23. The substrate processing apparatus as recited in claim 21,
wherein said chemical filter comprises at least one of activated
carbon, zeolite, a polymer membrane, polymer fiber, and non-woven
fabric, or a member chemically modified by at least one of
activated carbon, zeolite, a polymer membrane, polymer fiber, and
non-woven fabric.
24. The substrate processing apparatus as recited in claim 20,
wherein said volatile substance removal mechanism comprises a
combination filter including a chemical filter capable of removing
the volatile substance contained in the at least one of intake air
and circulation air and a particulate removal filter capable of
removing fine particles in the at least one of intake air and
circulation air.
25. The substrate processing apparatus as recited in claim 20,
wherein said volatile substance removal mechanism comprises a
scrubber operable to clean the at least one of intake air and
circulation air.
26. The substrate processing apparatus as recited in claim 20,
wherein said volatile substance removal mechanism comprises a
heating furnace operable to pyrolyze the volatile substance
contained in the at least one of intake air and circulation
air.
27. A substrate processing apparatus comprising: a plating unit
configured to plate a substrate so as to deposit a metal on a
surface of the substrate; a cleaning and drying unit configured to
clean and dry the substrate; a substrate transfer device operable
to transfer the substrate between said plating unit and said
cleaning and drying unit; and a pressure controller operable to
control a pressure of an interior of said substrate processing
apparatus so as to be lower than a pressure of an exterior of said
substrate processing apparatus and control pressures of interiors
of said plating unit and said cleaning and drying unit so as to be
lower than the pressure of the interior of said substrate
processing apparatus.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a substrate processing
apparatus having a plating apparatus for plating a substrate, and
more particularly to a substrate processing apparatus having a
plating apparatus for plating a substrate, such as a semiconductor
wafer, a glass substrate, or an interposer, to form
interconnections, such as large scale integrated circuits (LSI) or
plugs, in a surface of the substrate. The present invention is
particularly effective in reducing defects in interconnections
which would be caused by a plating process.
[0003] 2. Description of the Related Art
[0004] Materials for interconnections such as LSI have changed from
aluminum-based materials to copper-based materials. Accordingly,
there has been a growing tendency to employ a plating process to
form interconnections instead of a dry process such as chemical
vapor deposition (CVD) or physical vapor deposition (PVD). Thus,
plating apparatuses for performing such a plating process have
increasingly been required to have various additional functions.
Specifically, plating apparatuses have been required to perform
additional processes including an annealing process for heating a
plated film to grow grains (crystal grains) and promote
stabilization, an etching process for reducing steps on a surface
of a plated film, a polishing process for grinding or polishing a
surface of a plated film, an inspection process for measuring the
film thickness of a plated film or detecting defects of a plated
film, and the like. Particularly, an annealing process immediately
after deposition of a copper plated film has been widely employed
to uniformly grow and stabilize grains of the copper plated film so
as to uniformize the size of the grains and reduce the resistivity
of the plated film.
[0005] FIG. 1 shows an example of a conventional substrate
processing apparatus having a plating apparatus. As shown in FIG.
1, the conventional substrate processing apparatus has a plating
apparatus 810 and an annealing apparatus (additional process
apparatus) 800 provided separately from the plating apparatus 810.
The plating apparatus 810 includes four plating units 812, two
etching and cleaning units 814, a substrate placement stage 816, a
substrate placement stage 818 having a monitoring function, and
substrate transfer devices 820 and 822. The annealing apparatus 800
includes an annealing chamber 802 and a substrate transfer device
804.
[0006] In the conventional substrate processing apparatus,
substrate storage containers 806 are moved between the plating
apparatus 810 and the annealing apparatus 800 to transfer
substrates between the plating apparatus 810 and the annealing
apparatus 800. Accordingly, it is difficult to maintain a constant
standby time of substrates between the plating apparatus 810 and
the annealing apparatus 800. Changes of the standby time may cause
variations in size of resultant grains over surfaces of substrates
and thus inhibit homogeneity of a plated film. Further, in the
conventional substrate processing apparatus, the annealing
apparatus 800 needs to be provided separately from the plating
apparatus 810.
[0007] Recently, as shown in FIGS. 2 and 3, there has been
developed a substrate processing apparatus having a plating
apparatus and an annealing apparatus which are integrated with each
other. A substrate processing apparatus 830 shown in FIG. 2
includes an annealing chamber 832 connected to a sidewall of the
apparatus. A substrate is transferred to the annealing chamber 832
by a substrate transfer device 822. A substrate processing
apparatus 834 shown in FIG. 3 includes an annealing chamber 836
disposed adjacent to an etching and cleaning unit 814 in the
apparatus. A substrate is transferred to the annealing chamber 832
by a substrate transfer device 822.
[0008] Unlike the substrate processing apparatus shown in FIG. 1,
such an integrated substrate processing apparatus does not require
an additional annealing apparatus. Thus, it is possible to reduce
cost for a semiconductor fabrication process. Further, the
integration substrate processing apparatus can maintain standby
times of substrates between a plating process and an annealing
process at a constant value. Accordingly, grains are prevented from
spontaneously growing in a plated film at a room temperature.
[0009] Recently, porous organic materials such as a low-k material
have been employed for interlayer dielectrics. Accordingly,
technical issues that cannot be solved by the integration of the
apparatus have newly arisen. When a low-k material is subjected to
heating or application of an electron beam, bonding between
molecules is strengthened so as to reduce its volume. Specifically,
the low-k material is cured. Thus, stress concentration may be
caused at an interface between a plated film and an underlying
layer so as to greatly reduce the reliability of the plated
film.
[0010] Further, when a plating process is employed to form LSI
interconnections at 65 nm node or smaller node (interconnection
width of 100 nm or less), thermal hysteresis (thermal budget)
applied to interconnections may be reduced so that grains further
grow even after compulsory annealing. This phenomenon is considered
to be affected by the fact that a low-k material has a thermal
conductivity lower than conventional materials for insulating
films.
[0011] In order to avoid the above problems, an annealing process
should be performed for a longer period of time. Accordingly, a
throughput of the plating apparatus is considerably lowered by the
annealing process. Thus, there has been desired a substrate
processing apparatus which can perform an additional process such
as an annealing process in addition to a plating process without
lowering a throughput of the apparatus.
[0012] Further, there have been pointed out other problems such as
formation of native oxides or organic contamination on a surface of
a plating feed layer (seed layer). These problems depend on standby
times from a pre-plating process to a plating process or conditions
under which substrates are stored.
[0013] FIG. 4A is a plan view showing another arrangement of a
conventional plating apparatus. FIG. 4B is a side view of FIG. 4A.
As shown in FIGS. 4A and 4B, the plating apparatus 840 has three
plating units 812 for forming a plated film on a substrate, three
etching and cleaning units 814 for cleaning and drying the
substrate, a substrate transfer device 842 such as a robot for
transferring the substrate, and a chemical liquid management unit
844. A placement stage 846 on which two substrate storage
containers 806 are placed is disposed near an outer wall of the
plating apparatus 840.
[0014] The substrate transfer device 842 takes out a substrate
(e.g., semiconductor wafer) from one of the substrate storage
containers 806 and sequentially introduces it into each plating
unit 812 to perform a plating process on the substrate. Then, the
substrate transfer device 842 takes out the substrate having a
plated film formed thereon from the plating unit 812 and transfers
it to the etching and cleaning unit 814. In the etching and
cleaning unit 814, an etching process, a cleaning process, and a
drying process are performed on the substrate. The substrate
transfer device 842 takes out the dried substrate from the etching
and cleaning unit 814 and returns it to the other of the substrate
storage containers 806.
[0015] As shown in FIG. 4B, the plating apparatus 840 has a
particulate removal filter 850 provided at an upper portion of the
plating apparatus 840, such as a high-efficiency particulate air
filter (HEPA filter) or an ultra low penetration air filter (ULPA
filter). A portion of internal air in the plating apparatus 840 is
discharged as exhaust air 852 through a duct 854 to an exterior of
the plating apparatus 840. Another portion of the internal air in
the plating apparatus 840 is circulated as circulation air 856
through the particulate removal filter 850. Further, external air
is introduced as intake air 858 through the particulate removal
filter 850. The HEPA filter is capable of removing 0.3-micron
particles at a rate of 99.97%. The ULPA filter is capable of
removing 0.15-micron particles at a rate of 99.9995%. Air in each
of the plating units 812 is discharged as exhaust air 862 through a
dedicated exhaust duct 860 to the exterior of the plating apparatus
840. Further, air in the chemical liquid management unit 844 is
discharged as exhaust air 866 through an exhaust duct 864 to the
exterior of the plating apparatus 840.
[0016] In a conventional copper plating process, a copper seed
layer is formed by sputtering, chemical vapor deposition (CVD),
atomic layer deposition (ALD), or electroless plating. A copper
seed layer becomes thinner year by year as the size of
interconnections becomes smaller. The thickness of a copper seed
layer to form a device of 65-nm generation is around 600 angstroms
in a substrate field. The thickness of a copper seed layer to form
a device of 45-nm generation is expected to be less than 500
angstroms.
[0017] As a method of forming copper interconnections, there is
employed a method of plating a substrate with copper sulfate to
form copper interconnections on a thin copper seed layer. Then,
copper crystal is grown and stabilized by heating. An excessive
copper film is polished and removed by chemical mechanical
polishing (CMP). Generally, copper interconnections thus formed are
multilayered so as to have at least 10 layers for the purpose of
manufacturing LSI.
[0018] As interconnections become finer, defects of copper
interconnections become more problematic. For example, the term
"defects" means a state in which portions of copper
interconnections lacks, a state in which abnormal plating
deposition is caused at portions of copper interconnections so as
to produce irregularities on surfaces of the copper
interconnections, or singular points at which voids are likely to
be generated by a heating process after a plating process. Some
defects may be produced by deficiency of processes other than a
plating process. However, defects resulting from a plating process
tend to increase according to progress of scaledown of
interconnections. Such defects considerably inhibit improvement of
a yield of products.
[0019] It is considered that one of reasons why defects are
produced is adsorption of volatile substances (e.g., organic
solvent such as benzene, toluene, xylene, or amine, alkali such as
ammonia, and lower organic acid) on a surface of a substrate.
[0020] Further, an LSI fabrication process is performed in a clean
room, which is extremely cleaned. However, recent progress of local
cleaning technology including front opening unified pods (FOUP),
standard manufacturing interface pods (SMIF), and E-cube allows
cleanliness of a clean room to be lower than ten years ago. This is
because a clean room requires a large amount of investment. Such a
change of specification has an influence on increase of
defects.
SUMMARY OF THE INVENTION
[0021] The present invention has been made in view of the above
drawbacks. It is, therefore, a first object of the present
invention to provide a substrate processing apparatus which can
perform an additional process in addition to a plating process
without lowering a throughput of the apparatus and can upgrade the
additional process at a low cost.
[0022] A second object of the present invention is to provide a
substrate processing apparatus which can effectively reduce
interconnection defects caused by plating.
[0023] According to a first aspect of the present invention, there
is provided a substrate processing apparatus which can perform an
additional process in addition to a plating process without
lowering a throughput of the apparatus and can upgrade the
additional process at a low cost. The substrate processing
apparatus has a plating apparatus configured to plate a substrate
so as to deposit a metal on a surface of the substrate and an
additional process apparatus configured to perform an additional
process on the substrate. The plating apparatus has a substrate
placement stage on which the substrate to be transferred to the
additional process apparatus is placed. The additional process
apparatus has an additional process unit configured to perform the
additional process on the substrate and a substrate transfer device
operable to transfer the substrate between the substrate placement
stage of the plating apparatus and the additional process unit.
[0024] According to a second aspect of the present invention, there
is provided a substrate processing apparatus which can perform an
additional process in addition to a plating process without
lowering a throughput of the apparatus and can upgrade the
additional process at a low cost. The substrate processing
apparatus has a plating apparatus configured to plate a substrate
and an additional process apparatus configured to perform an
additional process on the substrate. The additional process
apparatus is disposed adjacent to the plating apparatus. The
plating apparatus has a plating unit configured to plate the
substrate so as to deposit a metal on a surface of the substrate, a
first substrate transfer device operable to transfer the substrate
in the plating apparatus, and a substrate placement stage on which
the substrate to be transferred to the additional process apparatus
is placed. The additional process apparatus has an additional
process unit configured to perform the additional process on the
substrate and a second substrate transfer device operable to
transfer the substrate between the substrate placement stage of the
plating apparatus and the additional process unit.
[0025] The plating apparatus and the additional process apparatus
may be disposed independently of each other. The additional process
unit may comprise an annealing unit configured to heat the
substrate, a cleaning unit configured to clean the substrate, an
etching unit configured to etch the substrate, a polishing unit
configured to polish the substrate, or a film thickness measurement
unit configured to measure a film thickness of the metal film
formed on the surface of the substrate. The plating apparatus may
be configured to fill fine recesses formed in the substrate with
the metal. The metal may contain at least one of copper, cobalt,
nickel, gold, and tin.
[0026] According to a third aspect of the present invention, there
is provided a substrate processing apparatus which can perform an
additional process in addition to a plating process without
lowering a throughput of the apparatus and can upgrade the
additional process at a low cost. The substrate processing
apparatus has a main process apparatus configured to perform a main
process on a substrate and an additional process apparatus
configured to perform an additional process on the substrate. The
main process apparatus has a substrate placement stage on which the
substrate to be transferred to the additional process apparatus is
placed. The additional process apparatus has an additional process
unit configured to perform the additional process on the substrate
and a substrate transfer device operable to transfer the substrate
between the substrate placement stage of the main process apparatus
and the additional process unit.
[0027] Since the substrate is transferred between the plating
apparatus and the additional process apparatus by the second
substrate transfer device of the additional process apparatus, the
substrate processing apparatus can perform an additional process in
addition to a plating process without lowering a throughput of the
apparatus. Further, when the plating apparatus and the additional
process apparatus are disposed independently of each other, the
additional process apparatus can be upgraded at low cost as needed.
For example, with regard to an annealing process, only an annealing
unit as the additional process apparatus can be retrofitted or
upgraded as needed. Further, when a heating mechanism in the
annealing unit is to be changed from a hot plate to other
mechanisms such as a lamp, an induction heater, an infrared heater,
or an electron beam applicator, a conventional substrate processing
apparatus should be modified as a whole. However, according to the
present invention, only an annealing unit can be replaced. Thus, it
is possible to remarkably reduce cost and labor for upgrade.
[0028] According to a fourth aspect of the present invention, there
is provided a substrate processing apparatus which can effectively
reduce interconnection defects caused by plating. The substrate
processing apparatus has a plating unit configured to plate a
substrate so as to deposit a metal on a surface of the substrate, a
cleaning and drying unit configured to clean and dry the substrate,
and a substrate transfer device operable to transfer the substrate
between the plating unit and the cleaning and drying unit. The
substrate processing apparatus also has an air supply system
configured to supply at least one of intake air and circulation air
into the substrate processing apparatus and a volatile substance
removal mechanism configured to remove a volatile substance
contained in the at least one of intake air and circulation air to
be supplied by the air supply system.
[0029] Since the volatile substance contained in the at least one
of intake air and circulation air is removed, the volatile
substance is prevented from being adsorbed on the surface of the
substrate in the substrate processing apparatus. Thus, defects are
prevented from being caused by plating. Accordingly, it is possible
to reduce defects resulting from a plating process with a small
amount of investment. Further, a yield of LSI products can be
improved so as to contribute to a low-cost production.
[0030] The volatile substance removal mechanism may comprise a
chemical filter capable of removing the volatile substance
contained in the at least one of intake air and circulation air.
When the volatile substance removal mechanism comprises such a
chemical filter, the volatile substance can effectively be captured
and removed by the chemical filter. Accordingly, defects can be
reduced more effectively.
[0031] In this case, the chemical filter may be provided at an
upper portion of the substrate processing apparatus. When the
chemical filter is provided at an upper portion of the substrate
processing apparatus, air from which the volatile substance has
been removed flows into the substrate processing apparatus to form
a downflow. Thus, it is possible to suitably form the downflow,
which is required in the substrate processing apparatus.
[0032] It is desirable that the chemical filter comprises at least
one of activated carbon, zeolite, a polymer membrane, polymer
fiber, and non-woven fabric, or a member chemically modified by at
least one of activated carbon, zeolite, a polymer membrane, polymer
fiber, and non-woven fabric. In this case, the chemical filter can
efficiently capture and remove a volatile substance including basic
gases such as ammonia and trimethylamine, acid gases such as SOx,
NOx, and chlorine, and organic gases such as xylene, toluene,
benzene, and siloxane. Particularly, it is possible to capture and
remove organic gases such as toluene and xylene that are considered
to be likely to cause and promote plating defects.
[0033] The volatile substance removal mechanism may comprise a
combination filter including a chemical filter capable of removing
the volatile substance contained in the at least one of intake air
and circulation air and a particulate removal filter capable of
removing fine particles in the at least one of intake air and
circulation air. In this case, the volatile substance removal
mechanism has functions of removing not only volatile substances
but also fine particles in the intake air and/or the circulation
air. Accordingly, it is possible to reduce defects more
effectively.
[0034] Alternatively, the volatile substance removal mechanism may
comprise a scrubber operable to clean the at least one of intake
air and circulation air. For example, when air to be introduced
into the substrate processing apparatus is supplied to the
scrubber, a volatile substance in the air is adsorbed in an
adsorbing solution. Thus, since air containing no volatile
substances is introduced into the substrate processing apparatus,
defects are prevented from being produced on the substrate.
[0035] The volatile substance removal mechanism may comprise a
heating furnace operable to pyrolyze the volatile substance
contained in the at least one of intake air and circulation air.
For example, when air to be introduced into the substrate
processing apparatus is supplied to the heating furnace, a volatile
substance in the air is pyrolyzed in the heating furnace. Thus,
since air containing no volatile substances is introduced into the
substrate processing apparatus, defects are prevented from being
produced on the substrate.
[0036] According to a fifth aspect of the present invention, there
is provided a substrate processing apparatus which can effectively
reduce interconnection defects caused by plating. The substrate
processing apparatus has a plating unit configured to plate a
substrate so as to deposit a metal on a surface of the substrate, a
cleaning and drying unit configured to clean and dry the substrate,
and a substrate transfer device operable to transfer the substrate
between the plating unit and the cleaning and drying unit. The
substrate processing apparatus also has a pressure controller
operable to control a pressure of an interior of the substrate
processing apparatus so as to be lower than a pressure of an
exterior of the substrate processing apparatus and control
pressures of interiors of the plating unit and the cleaning and
drying unit so as to be lower than the pressure of the interior of
the substrate processing apparatus.
[0037] Thus, the pressure of the interior of the substrate
processing apparatus is set to be lower than the pressure of the
exterior of the substrate processing apparatus. The pressures of
the interiors of the plating unit and the cleaning and drying unit
are set to be lower than the pressure of the interior of the
substrate processing apparatus. Accordingly, air contaminated by
chemical mist used in the substrate processing apparatus is
prevented from leaking out of the substrate processing apparatus.
Thus, even if the substrate processing apparatus is installed in a
clean room, the clean room is prevented from being contaminated by
the chemical mist used in the substrate processing apparatus.
[0038] The above and other objects, features, and advantages of the
present invention will be apparent from the following description
when taken in conjunction with the accompanying drawings which
illustrate preferred embodiments of the present invention by way of
example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a plan view showing an example of a conventional
substrate processing apparatus;
[0040] FIG. 2 is a plan view showing another example of a
conventional substrate processing apparatus;
[0041] FIG. 3 is a plan view showing another example of a
conventional substrate processing apparatus;
[0042] FIG. 4A is a plan view showing an example of a conventional
plating apparatus;
[0043] FIG. 4B is a side view of FIG. 4A;
[0044] FIG. 5 is a plan view showing a substrate processing
apparatus according to a first embodiment of the present
invention;
[0045] FIG. 6 is a schematic view showing a main portion of a
plating unit in the substrate processing apparatus shown in FIG.
5;
[0046] FIG. 7 is a schematic view showing an annealing unit as an
additional process unit in the substrate processing apparatus shown
in FIG. 5;
[0047] FIG. 8 is a schematic view showing an etching and cleaning
unit as an additional process unit in the substrate processing
apparatus shown in FIG. 5;
[0048] FIG. 9 is a schematic view showing a polishing unit as an
additional process unit in the substrate processing apparatus shown
in FIG. 5;
[0049] FIG. 10 is a schematic view showing an inspection unit as an
additional process unit in the substrate processing apparatus shown
in FIG. 5;
[0050] FIG. 11 is a plan view showing a substrate processing
apparatus according to a second embodiment of the present
invention;
[0051] FIG. 12 is a plan view showing a substrate processing
apparatus according to a third embodiment of the present
invention;
[0052] FIG. 13 is a plan view showing a substrate processing
apparatus according to a fourth embodiment of the present
invention;
[0053] FIG. 14 is a plan view showing a substrate processing
apparatus according to a fifth embodiment of the present
invention;
[0054] FIG. 15 is a plan view showing a substrate processing
apparatus according to a sixth embodiment of the present
invention;
[0055] FIG. 16 is a side view showing a plating apparatus according
to a seventh embodiment of the present invention;
[0056] FIG. 17 is a side view showing a plating apparatus according
to a ninth embodiment of the present invention;
[0057] FIG. 18 is a side view showing a plating apparatus according
to an eighth embodiment of the present invention;
[0058] FIG. 19 is a side view showing a plating apparatus according
to a tenth embodiment of the present invention;
[0059] FIG. 20 is a side view showing a plating apparatus according
to an eleventh embodiment of the present invention; and
[0060] FIG. 21 is a side view showing a plating apparatus according
to a twelfth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0061] A substrate processing apparatus according to embodiments of
the present invention will be described below with reference to
FIGS. 5 through 21. Like or corresponding parts are denoted by like
or corresponding reference numerals throughout drawings, and will
not be described below repetitively.
[0062] FIG. 5 is a plan view showing a substrate processing
apparatus 1 according to a first embodiment of the present
invention. As shown in FIG. 5, the substrate processing apparatus 1
has a rectangular plating apparatus 2 for plating a substrate such
as a semiconductor wafer having fine interconnection recesses and a
rectangular additional process apparatus 3 for performing an
additional process such as an annealing process, an etching
process, or a polishing process on the substrate. The additional
process apparatus 3 is connected to a longitudinal end of the
plating apparatus 2. In the present embodiment, the plating
apparatus 2 is employed as a main process apparatus for performing
a main process on a substrate. However, the main process apparatus
is not limited to a plating apparatus.
[0063] The plating apparatus 2 includes five plating units 20 each
for plating a substrate to deposit metal on a surface of the
substrate, two etching and cleaning units (cleaning and drying
units) 22 each for etching, cleaning, and drying the plated
substrate, a substrate placement stage 24 having a monitoring
function, a substrate placement stage 26 disposed adjacent to the
additional process apparatus 3, and a substrate transfer device 28
movable along a longitudinal direction of the plating apparatus 2.
The substrate placement stage 24, the two plating units 20, the
etching and cleaning unit 22, and the substrate placement stage 26
are disposed on one side of the substrate transfer device 28. The
three plating units 20 and the etching and cleaning unit 22 are
disposed on the other side of the substrate transfer device 28.
[0064] Substrate storage containers 4 such as standard
manufacturing interface pods (SMIF) or front opening unified pods
(FOUP), which can receive a number of substrates, are detachably
mounted to a longitudinal end of the plating apparatus 2. The
substrate transfer device 28 transfers a substrate between the
plating units 20, the etching and cleaning units 22, the substrate
placement stages 24 and 26, and the substrate storage containers
4.
[0065] As shown in FIG. 5, the additional process apparatus 3
includes an additional process unit 30 for performing an additional
process including an annealing process, an etching process, and a
polishing process on a substrate, and a substrate transfer device
32 disposed between the substrate placement stage 26 of the plating
apparatus 2 and the additional process unit 30. The substrate
transfer device 32 transfers a substrate between the substrate
placement stage 26 of the plating apparatus 2 and the additional
process unit 30.
[0066] A substrate is introduced from the substrate storage
container 4 into the plating apparatus 2 and transferred to the
plating unit 20 by the substrate transfer device 28. Thus, the
substrate is plated in the plating unit 20. The plated substrate is
transferred to the etching and cleaning unit 22 by the substrate
transfer device 28. In the etching and cleaning unit 22, a plated
film attached to an edge portion (bevel portion) of the substrate
is etched, and then the substrate is cleaned and dried.
[0067] After completion of the processes in the plating apparatus
2, the substrate is placed on the substrate placement stage 26 by
the substrate transfer device 28 and introduced into the additional
process unit 30 of the additional process apparatus 3 by the
substrate transfer device 32. An additional process including an
annealing process, an etching process, and a polishing process is
performed in the additional process unit 30. The substrate that has
been subjected to the additional process is returned to the
substrate placement stage 26 of the plating apparatus 2 by the
substrate transfer device 32. The substrate on the substrate
placement stage 26 is returned to the substrate storage container 4
by the substrate transfer device 28. The substrate storage
containers 4 may be provided not only on the plating apparatus 2,
but also on the additional process apparatus 3. In this case, the
substrate that has been subjected to the additional process is
returned directly to a substrate storage container (not shown)
provided on the additional process apparatus 3 by the substrate
transfer device 32.
[0068] As described above, the substrate processing apparatus 1 in
the present embodiment can perform or upgrade a diversified
additional process after the plating process at low cost and
becomes multifunctional without any influence on a standby time of
a substrate before or after the plating process or on a throughput
of the apparatus.
[0069] FIG. 6 is a schematic view showing a main portion of one of
the plating units 20. As shown in FIG. 6, the plating unit 20 has a
swing arm 600 which can be swung in a horizontal direction. An
electrode head 602 is rotatably supported by a tip end of the swing
arm 600. The plating unit 20 has a substrate stage 604 for holding
a substrate W in a state such that a surface of the substrate W to
be plated faces upward. The substrate stage 604 is disposed below
the electrode head 602 and is movable in a vertical direction. The
plating unit 20 includes a cathode unit 606 disposed above the
substrate stage 604 so as to surround a peripheral portion of the
substrate stage 604.
[0070] In the example shown in FIG. 6, the electrode head 602 has a
diameter slightly smaller than that of the substrate stage 604. The
entire surface of the substrate W held by the substrate stage 604
can substantially be plated without changing a relative position
between the electrode head 602 and the substrate stage 604. The
example shown in FIG. 6 employs a face-up plating unit, which
performs a plating process in a state such that a surface of a
substrate faces upward. However, the present invention is
applicable to a face-down plating unit, which performs a plating
process in a state such that a surface of a substrate faces
downward, or a vertical-set plating unit, which performs a plating
process in a state such that a substrate is placed in a vertical
direction.
[0071] The substrate stage 604 has a vacuum passage 604a defined
within the substrate stage 604 and an annular vacuum attraction
groove 604b defined at a peripheral portion of an upper surface of
the substrate stage 604. The vacuum attraction groove 604b
communicates with the vacuum passage 604a. Seal rings 608 and 610
are provided on inward and outward sides of the vacuum attraction
groove 604b, respectively. The substrate W is placed on the upper
surface of the substrate stage 604, and the vacuum attraction
groove 604b is evacuated through the vacuum passage 604a to attract
the peripheral portion of the substrate W. Thus, the substrate W is
held on the substrate stage 604.
[0072] The swing arm 600 is moved vertically by a servomotor and a
ball screw (not shown) and pivoted (swung) by a swing motor (not
shown). Pneumatic actuators may be used instead of the motors.
[0073] The cathode unit 606 has six divided cathode electrodes 612
and an annular seal member 614 disposed above the cathode
electrodes 612 so as to cover upper surfaces of the cathode
electrodes 612. The seal member 614 has an inner circumferential
portion inclined inward and downward. The thickness of the inner
circumferential portion is gradually reduced. The seal member 614
has an inner circumferential edge portion extending downward. When
the substrate stage 604 is moved upward, the peripheral portion of
the substrate W held by the substrate stage 604 is pressed against
the cathode electrodes 612 so as to flow a current to the substrate
W At the same time, the inner circumferential edge portion of the
seal member 614 is brought into pressure contact with an upper
surface of the peripheral portion of the substrate W so as to
hermetically seal the contact portion. Accordingly, a plating
solution that has been supplied onto the upper surface (surface to
be plated) of the substrate W is prevented from leaking out of an
edge portion of the substrate W, and the cathode electrodes 612 are
thus prevented from being contaminated by the plating solution. In
this embodiment, the cathode unit 606 is not movable in the
vertical direction but is rotatable together with the substrate
stage 604. However, the cathode unit 606 may be designed to be
movable in the vertical direction so that the seal member 614 is
brought into pressure contact with the surface of the substrate W
when the cathode unit 606 is moved downward.
[0074] The electrode head 602 includes a rotatable housing 622 and
a vertically movable housing 620 which are concentrically disposed.
Each of the rotatable housing 622 and the vertically movable
housing 620 has a bottomed cylindrical shape with a downwardly open
end. The rotatable housing 622 is fixed to a lower surface of a
rotating member 624 attached to a free end of the swing arm 600 so
that the rotatable housing 622 is rotated together with the
rotating member 624. The vertically movable housing 620 has an
upper portion positioned inside the rotatable housing 622. The
vertically movable housing 620 is rotated together with the
rotatable housing 622 and moved relative to the rotatable housing
622 in a vertical direction. The lower open end of the vertically
movable housing 620 is closed with a porous member 628 so as to
define an anode chamber 630 in the vertically movable housing 620.
The anode chamber 630 has a circular anode 626 dipped in a plating
solution Q which is introduced to the anode chamber 630.
[0075] In this example, the porous member 628 has a multilayered
structure having three laminated layers of porous materials.
Specifically, the porous member 628 includes a plating solution
impregnated material 632 which mainly serves to hold a plating
solution, and a porous pad 634 attached to a lower surface of the
plating solution impregnated material 632. The porous pad 634
includes a lower pad 634a adapted to be brought into direct contact
with the substrate W and an upper pad 634b disposed between the
lower pad 634a and the plating solution impregnated material 632.
The plating solution impregnated material 632 and the upper pad
634b are positioned in the vertically movable housing 620, and the
lower open end of the vertically movable housing 620 is closed by
the lower pad 634a. Thus, since the porous member 628 has a
multilayered structure, the porous pad 634 (the lower pad 634a)
which is brought into contact with the substrate W can have
flatness enough to flatten irregularities on the surface of the
substrate W to be plated.
[0076] The contact surface of the lower pad 634 which is brought
into contact with the surface of the substrate is required to have
a certain degree of flatness. Further, the lower pad 634 should
have fine through-holes therein for allowing a plating solution to
pass therethrough. Furthermore, at least the contact surface of the
lower pad 634a should be made of an insulator or a material having
high insulating properties. The surface of the lower pad 634a is
required to have a maximum roughness (RMS) of about several tens of
micrometers or less.
[0077] It is desirable that the fine through-holes of the lower pad
634a have a circular cross section in order to maintain flatness of
the contact surface. Optimum diameters of the fine through-holes
and an optimum number of the fine through-holes per unit area vary
depending on the kind of a plated film and an interconnect pattern.
However, it is desirable that both of the diameters and number of
the fine through-holes are as small as possible in view of
improving the selectivity of a plated film growing in the fine
through-holes. Specifically, the diameter of each fine through-hole
may be not more than 30 .mu.m, preferably in the range of 5 to 20
.mu.m. The number of the fine through-holes may be set so that the
lower pad 634a has a porosity of not more than 50%. Further, it is
desirable that the lower pad 634a has a certain degree of hardness.
For example, the lower pad 634a may have a tensile strength ranging
from about 5 to 100 kg/cm.sup.2 and a bend elastic constant ranging
from about 200 to 10000 kg/cm.sup.2.
[0078] Furthermore, it is desirable that the lower pad 634a is made
of hydrophilic material. For example, the following materials may
be subjected to hydrophilic treatment or polymerized with a
hydrophilic group. Examples of such materials include porous
polyethylene (PE), porous polypropylene (PP), porous polyamide,
porous polycarbonate, and porous polyimide. The porous
polyethylene, the porous polypropylene, the porous polyamide, and
the like are produced as follows. Fine powder of
ultrahigh-molecular polyethylene, polypropylene, and polyamide, or
the like is used as a material, squeezed, and sintered. These
materials are commercially available by the name of Firudasu.TM.
(by Mitsubishi Plastics, Inc.), Sunfine.TM. UF and Sunfine.TM. AQ
(by Asahi Kasei Corporation), Spacy.TM. (by Spacy Chemical
Corporation), and the like. Porous polycarbonate may be produced by
passing a high-energy heavy metal such as copper, which has been
accelerated by an accelerator, through a polycarbonate film to form
straight tracks, and then selectively etching the tracks. The lower
pad 634a may be produced by pressing or machining the surface of
the lower pad 634a which is brought into contact with the surface
of the substrate W to a flat finish. In this case,
high-preferential deposition is expected to be carried out in fine
recesses or grooves.
[0079] The plating solution impregnated material 632 is formed of
porous ceramics such as alumina, SiC, mullite, zirconia, titania,
or cordierite, a hard porous member such as a sintered compact of
polypropylene or polyethylene, a composite material including these
materials, woven fabric, or non-woven fabric. For example,
alumina-based ceramics have a pore diameter of 30 to 200 .mu.m.
Further, SiC has a pore diameter of not more than 30 .mu.m, a
porosity of 20 to 95%, and a thickness of 1 to 20 mm, preferably 5
to 20 mm, more preferably 8 to 15 mm. In this embodiment, the
plating solution impregnated material 632 is formed of porous
alumina ceramics having a porosity of 30% and an average pore
diameter of 100 .mu.m. Although the porous ceramic plate per se is
an insulator, the porous ceramic plate is constructed such that a
plating solution is introduced into complicated passages in the
porous ceramic which are considerably long in the thickness
direction so as to have a smaller conductivity than the plating
solution.
[0080] In this manner, the plating solution impregnated material
632 is disposed in the anode chamber 630 so as to provide a high
resistance. Accordingly, influence of a resistance of a copper film
layer (plated film) can be reduced to a negligible degree. Thus, a
difference in current density over the surface of the substrate W
due to electrical resistance on the surface of the substrate W can
be made small so as to improve the uniformity of the plated film
over the surface of the substrate.
[0081] The electrode head 602 has a pressing mechanism such as an
air bag 640 for pressing the lower pad 634a against the surface of
the substrate W held by the substrate stage 604 under a desired
pressure. Specifically, in this embodiment, the annular air bag
(pressing mechanism) 640 is provided between a lower surface of a
top wall of the rotatable housing 622 and an upper surface of a top
wall of the vertically movable housing 620 and connected to a
pressurized fluid source (not shown) through a fluid introduction
pipe 642.
[0082] The swing arm 600 is fixed at a predetermined position
(process position) so as not to move in the vertical direction, and
then the interior of the air bag 640 is pressurized under a
pressure P. Thus, the lower pad 634a is uniformly pressed against
the surface of the substrate W held by the substrate stage 604
under a desired pressure. Thereafter, the pressure P is restored to
an atmospheric pressure so as to release pressing of the lower pad
634a against the substrate W
[0083] A plating solution introduction pipe 644 is connected to the
vertically movable housing 620 to introduce the plating solution
into the interior of the vertically movable housing 620. A
pressurized fluid introduction pipe (not shown) is connected to the
vertically movable housing 620 to introduce a pressurized fluid
into the interior of the vertically movable housing 620. The anode
626 has a number of pores 626a formed therein. A plating solution Q
is introduced through the plating solution introduction pipe 644
into the anode chamber 630. The interior of the anode chamber 630
is pressurized. Thus, the plating solution Q reaches the upper
surface of the plating solution impregnated material 632 through
the pores 626a of the anode 626. The plating solution Q passes
through the plating solution impregnated material 632 and the
porous pad 634 (the upper pad 634b and the lower pad 634a). As a
result, the plating solution reaches an upper surface of the
substrate W held by the substrate stage 604.
[0084] The anode chamber 630 includes gases generated by chemical
reaction therein. Accordingly, the pressure in the anode chamber
630 may be varied. Therefore, the pressure in the anode chamber 630
is controlled to a predetermined set value by a feedback control
during the plating process.
[0085] For example, in the case of performing a copper plating
process, the anode 626 is made of copper containing 0.03 to 0.05%
of phosphorus (phosphorus-containing copper) in order to prevent
slime formation. The anode 626 may comprise an insoluble metal such
as platinum or titanium, or an insoluble electrode of a metal on
which platinum or the like is plated. The insoluble metal or the
insoluble electrode is preferable because replacement is
unnecessary. Further, the anode 626 may be a meshed anode which
allows a plating solution to readily pass therethrough.
[0086] The cathode electrodes 612 are electrically connected to a
cathode of a plating power source 650, and the anode 626 is
electrically connected to an anode of the plating power source
650.
[0087] Next, operation of performing a plating process in the
plating unit 20 will be described below. First, a substrate W is
attracted to and held on the upper surface of the substrate stage
604. The substrate stage 604 is raised so as to bring a peripheral
portion of the substrate W into contact with the cathode electrodes
612. Thus, a current can be supplied to the substrate W Then, the
substrate stage 604 presses the seal member 614 against the upper
surface of the peripheral portion of the substrate W so as to
hermetically seal the peripheral portion of the substrate W
[0088] The electrode head 602 is moved from a position (idling
position) where replacement of the plating solution, removal of
bubbles, and the like are conducted during idling to a
predetermined position (process position) in a state such that the
plating solution Q is held inside the electrode head 602.
Specifically, the swing arm 600 is raised and further pivoted to
locate the electrode head 602 right above the substrate stage 604.
Thereafter, the electrode head 602 is lowered. When the electrode
head 602 reaches the predetermined position (process position), the
electrode head 602 is stopped. Then, the anode chamber 630 is
pressurized, and the plating solution Q held by the electrode head
602 is discharged from the lower surface of the porous pad 634.
Next, pressurized air is introduced into the air bag 640 to press
the lower pad 634a downward. Thus, the lower pad 634a is pressed
against the upper surface (surface to be plated) of the substrate W
held by the substrate stage 604 under a desired pressure.
[0089] The lower pad 634a makes two revolutions, for example, at a
speed of 1 revolution/second in a state such that the lower pad
634a is brought into contact with the surface of the substrate W
Then, rotation of the lower pad 634a is stopped. Thus, the lower
pad 634a is rubbed against the surface of the substrate W.
Alternatively, the lower pad 634a may be stationary while the
substrate W may be rotated. The cathode electrodes 612 are
electrically connected to the cathode of the plating power source
650 and the anode 626 is electrically connected to the anode of the
plating power source 650 preferably within two seconds after
rotation of the lower pad 634a is stopped. Thus, a plating process
on the surface of the substrate W to be plated is started.
[0090] The plating process is performed for a certain period of
time. Then, the cathode electrodes 612 and the anode 626 are
disconnected from the plating power source 650. The anode chamber
630 is restored to an atmospheric pressure. Further, the air bag
640 is restored to an atmospheric pressure to release pressing of
the lower pad 634a against the substrate W. Then, the electrode
head 602 is raised.
[0091] The above operation is repeated a predetermined number of
times, if necessary. Thus, the copper layer (plated film) having a
sufficient film thickness enough to fill fine interconnection
recesses is formed on the surface of the substrate W. Then, the
electrode head 602 is pivoted and returned to its original position
(idling position). In the present embodiment, copper is filled into
interconnection recesses of a substrate. However, cobalt, nickel,
gold, or tin may be filled into interconnection recesses of a
substrate.
[0092] Next, there will be described an example in which an
annealing unit for heating a substrate is provided as the
additional process unit 30. FIG. 7 is a schematic view showing an
annealing unit 30a as the additional process unit. As shown in FIG.
7, the annealing unit 30a has a plurality of annealing chambers 700
stacked in a vertical direction. The number of the stacked
annealing chambers 700 is set at an optimum value based on a
required throughput or a required process time.
[0093] Each of the annealing chambers 700 includes a heating
chamber 702 for heating a substrate and a cooling chamber 704 for
cooling the substrate. The cooling chamber 704 has shutters 706 and
708. The heating chamber 702 has a hot plate 710 for heating the
substrate, for example, to 400.degree. C. and a plurality of
vertically movable pins 712 extending through the hot plate 710 in
the vertical direction. The vertically movable pins 712 are used to
hold a substrate placed on upper ends of the vertically movable
pins 712. The cooling chamber 704 has a cool plate 714 for cooling
the substrate, for example, by cooling water flowing through the
cool plate 714 and a plurality of vertically movable pins 716
extending through the cool plate 714 in the vertical direction. The
vertically movable pins 716 are used to hold a substrate placed on
upper ends of the vertically movable pins 716.
[0094] A substrate is introduced through the shutters 706 and 708
into the heating chamber 702 and held by the vertically movable
pins 712 in the heating chamber 702. Then, the vertically movable
pins 712 are lowered until a distance between the substrate and the
hot plate 710 becomes about 0.1 to 1.0 mm. At that state, the
substrate is heated, for example, to 400.degree. C. by the hot
plate 710. At that time, a gas for preventing oxidation is
introduced into the heating chamber 702 to prevent the substrate
from being oxidized. Thus, the substrate is annealed. The annealing
process is continued for several tens of seconds to about 60
seconds. The heating temperature of the substrate is set to be in a
range of 100 to 600.degree. C.
[0095] After completion of the annealing process, the substrate is
moved to the cooling chamber 704 and held by the vertically movable
pins 716 in the cooling chamber 704. Then, the vertically movable
pins 716 are lowered until a distance between the substrate and the
cool plate 714 becomes about 0 to 0.5 mm. At that state, cooling
water is introduced into the cool plate 714 to cool the substrate,
for example, to 100.degree. C. or less for about 10 to 60 seconds.
The cooled substrate is transferred to the substrate storage
container 4 by the substrate transfer device 32 in the additional
process apparatus 3.
[0096] Next, there will be described an example in which an etching
and cleaning unit for etching and cleaning a substrate is provided
as the additional process unit 30. FIG. 8 is a schematic view
showing an etching and cleaning unit 30b as the additional process
unit. As shown in FIG. 8, the etching and cleaning unit 30b has a
substrate stage 720 for horizontally holding a substrate and
rotating the substrate at a high speed, a motor 722 for rotating
the substrate stage 720, and a waterproof cover 724 surrounding the
substrate stage 720.
[0097] In the etching and cleaning unit 30b, ultrapure water 726,
nitrogen or dry air 728, and etching chemical liquid or
pre-treatment liquid 730 are jetted to upper and lower surfaces of
the substrate W Thus, the substrate W is subjected to
pre-treatment, cleaning, and etching. For example, it is possible
to etch excessive metal at a peripheral portion of the substrate W
or etch the substrate W for the purpose of reducing steps formed on
a surface of the substrate W during plating. Further, after the
etching process and the cleaning process, the substrate stage 720
may be rotated at a high speed to dry the substrate W.
Alternatively, a rinser drier or a spin-drier employing a dry gas
may be used in the etching and cleaning unit 30b to dry the
substrate W.
[0098] Next, there will be described an example in which a
polishing unit for polishing a substrate is provided as the
additional process unit 30. FIG. 9 is a schematic view showing a
polishing unit 30c as the additional process unit. As shown in FIG.
9, the polishing unit 30c includes a polishing table 742 having a
polishing pad (or a fixed abrasive) 740 attached to an upper
surface of the polishing table 742 and a top ring 744 for holding a
substrate W and pressing the substrate against the polishing table
742.
[0099] The polishing table 742 is coupled to a scroll motor 746
disposed below the polishing table 742. Thus, when the scroll motor
746 is driven, the polishing table 742 makes a translational
rotation movement. The top ring 744 is coupled through a top ring
shaft 748 to a rotation motor 750. Thus, when the rotation motor
750 is driven, the top ring 744 is rotated about the top ring shaft
748.
[0100] In the polishing unit 30c, a polishing liquid (e.g., slurry
752 or ultrapure water 754) is supplied to an upper surface of the
polishing pad 740. The substrate W is pressed against the polishing
table 742 by the top ring 744 to polish a surface of the substrate
W to a flat mirror finish. The purpose of the polishing unit 30c is
not limited to such chemical mechanical polishing. For example, the
polishing unit 30c may perform a process to reduce steps on a
surface of a plated substrate, such as high-speed grinding by a
fixed abrasive, rough polishing by electrolytic etching, or normal
grinding.
[0101] Next, there will be described an example in which an
inspection unit for measuring the film thickness of a plated film
formed on a surface of a substrate is provided as the additional
process unit 30. FIG. 10 is a schematic view showing an inspection
unit 30d as the additional process unit. As shown in FIG. 10, the
inspection unit 30d has an X-Y stage 760 for moving a substrate W
on the horizontal plane in a state such that a plated surface of
the substrate W faces upward, and a sensor 762 for inspecting the
substrate W on the X-Y stage 760.
[0102] The substrate W is chucked by the X-Y stage 760. The sensor
762 is brought close to the plated surface of the substrate W Then,
the X-Y stage 760 is moved on the horizontal plane. Thus, the
surface of the substrate W can be inspected at desired points. The
sensor 762 may comprise a film thickness sensor, a particle
counter, a surface roughness sensor, a reflectometer, an image
recognition sensor, or the like. Thus, the sensor 762 can detect
the film thickness of a plated film, an underlying film, or a
native oxide, the surface contamination, or the reflectance, the
surface roughness, or irregularities of the plated film. Further,
defects in interconnections formed on the substrate W (e.g., metal
lack or pits) can be detected based on changes of an image at a
specific area of the substrate or comparison of relative scatter
intensity.
[0103] FIG. 11 is a plan view showing a substrate processing
apparatus 101 according to a second embodiment of the present
invention. As with the substrate processing apparatus 1 in the
first embodiment, the substrate processing apparatus 101 has a
rectangular plating apparatus 102. The plating apparatus 102 has a
pre-treatment unit 121 in addition to the arrangement of the
plating apparatus 2 in the first embodiment. Other portions are
similar to the arrangement of the substrate processing apparatus 1
in the first embodiment.
[0104] FIG. 12 is a plan view showing a substrate processing
apparatus 201 according to a third embodiment of the present
invention. As with the substrate processing apparatus 1 in the
first embodiment, the substrate processing apparatus 201 has a
rectangular plating apparatus 202. The plating apparatus 202
includes four plating units 20, two etching and cleaning units 22,
a substrate placement stage 224 having a monitoring function, a
pre-treatment unit 121, a substrate transfer device 28 movable
along a longitudinal direction of the plating apparatus 202, a
substrate transfer device 223 for transferring a substrate from or
to substrate storage containers 4, and a substrate placement stage
225 disposed between the substrate transfer device 28 and the
substrate transfer device 223. The substrate placement stage 224 is
disposed adjacent to an additional process apparatus 3. The
additional process apparatus 3 includes a substrate transfer device
32 for transferring a substrate between the substrate placement
stage 224 and an additional process unit 30.
[0105] FIG. 13 is a plan view showing a substrate processing
apparatus 301 according to a fourth embodiment of the present
invention. The substrate processing apparatus 301 has a rectangular
plating apparatus 302 and two additional process apparatuses 303a
and 303b. The plating apparatus 302 includes four plating units 20,
two etching and cleaning units 22, a substrate placement stage 324
having a monitoring function, a substrate transfer device 28
movable along a longitudinal direction of the plating apparatus
302, a substrate transfer device 223 for transferring a substrate
from or to substrate storage containers 4, a substrate placement
stage 225 disposed between the substrate transfer device 28 and the
substrate transfer device 223, a substrate placement stage 326a
disposed adjacent to the additional process apparatus 303a, and a
substrate placement stage 326b disposed adjacent to the additional
process apparatus 303b. Each of the additional process apparatuses
303a and 303b has a substrate transfer device 32 for transferring a
substrate between the substrate placement stage 326a or 326b and an
additional process unit 30.
[0106] FIG. 14 is a plan view showing a substrate processing
apparatus 401 according to a fifth embodiment of the present
invention. The substrate processing apparatus 401 has a rectangular
plating apparatus 302 with a recess 402a and an additional process
apparatus 403 disposed within the recess 402a. The plating
apparatus 402 includes four plating units 20, two etching and
cleaning units 22, a substrate placement stage 424 having a
monitoring function, a substrate transfer device 28 movable along a
longitudinal direction of the plating apparatus 402, a substrate
transfer device 223 for transferring a substrate from or to
substrate storage containers 4, and a substrate placement stage 225
disposed between the substrate transfer device 28 and the substrate
transfer device 223. The substrate placement stage 225 is disposed
adjacent to the additional process apparatus 403. The additional
process apparatus 403 has a substrate transfer device 32 for
transferring a substrate between the substrate placement stage 225
and an additional process unit 30.
[0107] FIG. 15 is a plan view showing a substrate processing
apparatus 501 according to a sixth embodiment of the present
invention. The substrate processing apparatus 501 has a plating
apparatus 502 and an additional process apparatus 503 disposed near
a corner of the plating apparatus 502. The plating apparatus 502
includes three plating units 20, two etching and cleaning units 22,
a substrate placement stage 526 disposed adjacent to the additional
process apparatus 503, a substrate transfer device 528, a substrate
placement stage 524 having a monitoring function, a substrate
transfer device 223 for transferring a substrate from or to
substrate storage containers 4, and a chemical liquid management
unit 529 for managing a chemical liquid such as a plating solution.
As shown in FIG. 15, the substrate transfer device 528 is disposed
at a central portion of the plating units 20, the etching and
cleaning units 22, a pre-treatment unit 121, and the substrate
placement stage 526. Thus, the units are arranged in the form of a
cluster in the plating apparatus 502. The additional process
apparatus 503 has a substrate transfer device 32 for transferring a
substrate between the substrate placement stage 526 and an
additional process unit 30.
[0108] In the above embodiments, the substrate processing apparatus
has a plating apparatus and at least one additional process
apparatus. However, the present invention is not limited to a
combination of a plating apparatus and an additional process
apparatus. The present invention is applicable to any combination
of a main process apparatus for performing a main process on a
substrate (e.g., a CMP apparatus or a cleaning apparatus) and an
additional process apparatus for performing an additional process
on the substrate.
[0109] FIG. 16 is a side view showing a plating apparatus 502a
according to a seventh embodiment of the present invention. In FIG.
16, the plating apparatus 502a has a combination filter 530
including a chemical filter 540 and a particulate removal filter
550 such as a HEPA filter or an ULPA filter. The chemical filter
540 serves as a removal mechanism for volatile organic substances.
The combination filter 530 is provided inside of the plating
apparatus 502a at an upper portion thereof The particulate removal
filter 550 comprises a HEPA filter or an ULPA filter as described
above and has a function of removing fine particles. The chemical
filter 540 has a function of removing volatile substances. Thus,
the combination filter 530 including both of the chemical filter
540 and the particulate removal filter 550 has functions of
removing volatile substances and removing fine particles.
[0110] A portion of internal air in the plating apparatus 502a is
discharged as exhaust air 552 through a duct 554 to an exterior of
the plating apparatus 502a. Another portion of the internal air in
the plating apparatus 502a is circulated as circulation air 556
through the combination filter 530. Further, external air is
introduced as intake air 558 through the combination filter 530.
Specifically, the plating apparatus 502a has an air supply system
for supplying the intake air 558 and the circulation air 556 to the
interior of the plating apparatus 502a. Air in each of the plating
units 20 is discharged as exhaust air 562 through a dedicated
exhaust duct 560 to the exterior of the plating apparatus 502a.
Further, air 563 flows into the chemical liquid management unit 529
from a region in which the plating units 20 and the etching and
cleaning units 22 are installed. Air in the chemical liquid
management unit 529 is discharged as exhaust air 566 through an
exhaust duct 564 to the exterior of the plating apparatus 502a. As
shown in FIG. 16, a placement stage 546 is disposed near the
plating apparatus 502a. A plurality of substrate storage containers
4 are placed on the placement stage 546.
[0111] The chemical filter 540 may employ activated carbon,
activated carbon to which chemicals are added, porous members,
plastic fiber having various functional groups, films having
various functional groups, non-woven fabric having various
functional groups, zeolite, a polymer membrane, polymer fiber, and
the like. The chemical filter 540 may be chemically modified by
these substances. The chemical filter 540 can remove volatile
substances including basic gases such as ammonia and
trimethylamine, acid gases such as SOx, NOx, and chlorine, and
organic gases such as xylene, toluene, benzene, and siloxane.
Volatile substances removed by the chemical filter 540 are not
limited to these substances. It has been revealed that organic
gases such as toluene and xylene are likely to cause and promote
plating defects.
[0112] These volatile organic substances may be adsorbed on a
surface of a substrate (a surface of a Cu seed layer or a barrier
metal). The volatile organic substances are not mixed into a
plating solution. Thus, the volatile organic substances repel a
plating solution so as to produce plating defects. While the
particulate removal filter 550 such as a HEPA filter or an ULPA
filter removes these volatile organic substances at a low removal
rate, the chemical filter 540 such as activated carbon can remove
the volatile organic substances at a remarkably high removal rate.
According to experimental results, the density of plating defects
was reduced from 5.5 points per substrate to 0.1 point per
substrate by the chemical filter 540 in the plating apparatus
502a.
[0113] FIG. 17 is a side view showing a plating apparatus 502b
according to a ninth embodiment of the present invention. The
plating apparatus 502b shown in FIG. 17 differs from the plating
apparatus 502a shown in FIG. 16 in that a combination filter 530
including a particulate removal filter 550 and a chemical filter
540 is provided outside of the plating apparatus 502b on an upper
wall thereof, and that circulation air 556 is introduced only
through the particulate removal filter 550 into the plating
apparatus 502b. As with the seventh embodiment shown in FIG. 16,
external intake air 558 is introduced through the combination
filter 530 including the particulate removal filter 550 and the
chemical filter 540 into the plating apparatus 502b.
[0114] FIG. 18 is a side view showing a plating apparatus 502c
according to an eighth embodiment of the present invention. As
shown in FIG. 18, the plating apparatus 502c has a combination
filter 530 including a chemical filter 540 and a particulate
removal filter 550 such as a HEPA filter or an ULPA filter. The
combination filter 530 is provided outside of the plating apparatus
502c on an upper wall thereof Both of circulation air 556 and
external intake air 558 are introduced through the combination
filter 530 including the particulate removal filter 550 and the
chemical filter 540 into the plating apparatus 502c.
[0115] Locations at which the chemical filter 540 is provided are
not limited to the illustrated examples. Nevertheless, it is
desirable to provide a chemical filter 540 inside of a plating
apparatus at an upper portion thereof or outside of a plating
apparatus on an upper wall thereof as shown in FIGS. 16 through 18
because downflow of clean air is required to be formed in the
plating apparatus.
[0116] FIG. 19 is a side view showing a plating apparatus 502d
according to a tenth embodiment of the present invention. The
plating apparatus 502d has a scrubber 570 as a removal mechanism
for volatile organic substances. External intake air 559 is
introduced into the scrubber 570. Intake air 558 discharged from
the scrubber 570 is introduced through a particulate removal filter
550, which is provided inside of the plating apparatus 502d at an
upper portion thereof, into the plating apparatus 502d. The
particulate removal filter 550 comprises a HEPA filter or an ULPA
filter as described above.
[0117] The scrubber 570 includes a pump 571, a pipe 572, a spray
pipe 573, an induced draft fan 575, and a lower tank 576. The lower
tank 576 stores an absorbing solution 574 therein. The absorbing
solution 574 is supplied through the pipe 572 to the spray pipe 573
by the pump 571. Thus, the absorbing solution 574 is sprayed
downward from the spray pipe 573. The intake air 559 is forced to
flow upward through the pipe 572 by the induced draft fan 575. At
that time, volatile substances contained in the intake air 559 are
brought into contact with the absorbing solution 574 and absorbed
in the absorbing solution 574. Thus, the volatile substances are
removed from the intake air 559. Intake air 558 from which volatile
substances have been removed is supplied through the particulate
removal filter 550 into the plating apparatus 502d. The scrubber
570 may employ water as the absorbing solution 574. However, any
solvent can be employed as the absorbing solution 574 as long as it
can remove organic substances.
[0118] FIG. 20 is a side view showing a plating apparatus 502e
according to an eleventh embodiment of the present invention. The
plating apparatus 502e has a thermal cracking furnace 580 as a
removal mechanism for volatile organic substances. The thermal
cracking furnace 580 comprises a heating furnace or a heating
furnace combined with a catalyst. External intake air 559 is
introduced into the thermal cracking furnace 580 by a fan 581.
Volatile organic substances contained in the intake air 559 are
pyrolyzed in the thermal cracking furnace 580. Intake air 558 in
which volatile organic substances are pyrolyzed is introduced
through the combination filter 530, which is provided inside of the
plating apparatus 502e at an upper portion thereof, into the
plating apparatus 502e. The combination filter 530 comprises a
chemical filter 540 and a particulate removal filter 550 such as a
HEPA filter or an ULPA filter.
[0119] When the thermal cracking furnace 580 comprises a heating
furnace combined with a catalyst, palladium, platinum, zirconium,
or the like is generally employed as a catalyst. However, the
catalyst is not limited to these examples. The heating temperature
of the thermal cracking furnace 580 is determined based on
pyrolysis properties of volatile organic substances to be
removed.
[0120] FIG. 21 is a side view showing pressures inside and outside
of a plating apparatus 502f according to a twelfth embodiment of
the present invention. The plating apparatus 502f has a pressure
controller 590 for controlling a pressure P.sub.0 of a clean room
in which the plating apparatus 502f is installed, a pressure
P.sub.1 of a region in which the plating units 20 and the etching
and cleaning units 22 are installed, and a pressure P.sub.2 of the
interior of the plating units 20 so as to meet the following
inequality.
[0121] P.sub.0>P.sub.1>P.sub.2
[0122] The region in which the plating units 20 and the etching and
cleaning units 22 are installed in the plating apparatus 502f may
contain hydrogen chloride or sulfuric acid mist which is produced
from a plating solution, or an alkali liquid (TMAH) or a reducing
agent (formalin) which is contained in an electroless plating
solution. Accordingly, it is necessary to maintain the pressure of
the interior of the plating apparatus 502f so as to be lower than
the pressure of the external space (clean room). However, because a
recent clean room has a cleanliness of about class 1000, it is
necessary to provide a particulate removal filter 550 such as a
HEPA filter or an ULPA filter for intake air 558 to be introduced
from the external space (clean room). Since chemical liquids are
used in the plating units 20 and the etching and cleaning units 22,
air is forced to be discharged from the units. Thus, the pressure
in the units is maintained so as to be lowest in the substrate
processing apparatus. The relationship of the pressures inside and
outside of the plating apparatus 502f as shown in FIG. 21 is
applicable to a substrate processing apparatus shown in FIGS. 5
through 20.
[0123] In the above embodiments, the etching and cleaning units 22
may comprise a cleaning and drying chamber for cleaning and drying
a substrate. The substrate processing apparatus may include a
substrate loading/unloading unit.
[0124] According to the present invention, volatile substances,
which would cause plating defects, are prevented from entering the
plating apparatus. Accordingly, it is possible to forestall
adsorption of the volatile substances on a surface of a seed layer
of a substrate. Thus, defects caused by plating can remarkably be
reduced at low cost. The present invention is applicable not only
to a plating apparatus but also to other deposition apparatuses,
polishing apparatuses, cleaning apparatuses, and etching
apparatuses.
[0125] Although certain preferred embodiments of the present
invention have been shown and described in detail, it should be
understood that various changes and modifications may be made
therein without departing from the scope of the appended
claims.
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