U.S. patent application number 11/792812 was filed with the patent office on 2008-05-08 for plating device, plating method, semiconductor device, and method for manufacturing semiconductor device.
Invention is credited to Yoshihide Iwazaki.
Application Number | 20080105555 11/792812 |
Document ID | / |
Family ID | 36587768 |
Filed Date | 2008-05-08 |
United States Patent
Application |
20080105555 |
Kind Code |
A1 |
Iwazaki; Yoshihide |
May 8, 2008 |
Plating Device, Plating Method, Semiconductor Device, And Method
For Manufacturing Semiconductor Device
Abstract
An object of the present invention is to provide a face-down
type jet plating device in which deterioration in plating quality
due to minute solid foreign matters derived from a black film etc.
is prevented without impairing operativity. The plating device is
designed such that a partition (7) is provided between a
semiconductor wafer (1) and an anode (5) so that the anode (5) and
the semiconductor wafer (7) are separated from each other and a
plating tank (100) is divided into a substrate-to-be-plated chamber
and an anode chamber.
Inventors: |
Iwazaki; Yoshihide; (Kyoto,
JP) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Family ID: |
36587768 |
Appl. No.: |
11/792812 |
Filed: |
December 8, 2005 |
PCT Filed: |
December 8, 2005 |
PCT NO: |
PCT/JP05/22539 |
371 Date: |
June 12, 2007 |
Current U.S.
Class: |
205/99 ;
204/275.1; 205/135; 205/148; 257/E21.175; 257/E21.508 |
Current CPC
Class: |
H01L 2224/05647
20130101; H01L 2224/0615 20130101; H01L 2924/01024 20130101; H01L
2924/04953 20130101; H01L 2224/13022 20130101; H01L 21/2885
20130101; C25D 7/123 20130101; C25D 21/06 20130101; H01L 2924/01005
20130101; H01L 2924/01029 20130101; C25D 5/02 20130101; H01L 24/05
20130101; H01L 2224/05184 20130101; H01L 24/11 20130101; H01L
2924/01019 20130101; H01L 2924/01015 20130101; H01L 2924/01082
20130101; H01L 2924/01011 20130101; H01L 24/03 20130101; H01L
2924/01022 20130101; C25D 17/10 20130101; H01L 2924/01078 20130101;
H01L 2924/01074 20130101; H01L 2224/05001 20130101; H01L 2224/1148
20130101; H01L 2224/13099 20130101; C25D 17/002 20130101; H01L
2224/05147 20130101; H01L 2224/05548 20130101; H01L 2224/13024
20130101; H01L 2924/01027 20130101; H01L 2224/05022 20130101; C25D
17/02 20130101; H01L 2224/05171 20130101; C25D 5/08 20130101; H01L
2224/05008 20130101; H01L 2924/01033 20130101; H01L 2924/01006
20130101; H01L 2224/023 20130101; H01L 2224/05166 20130101; H01L
2924/01079 20130101; H01L 2224/05569 20130101; H01L 2924/01075
20130101; H01L 2924/014 20130101; C25D 17/001 20130101; H01L
2224/05647 20130101; H01L 2924/00014 20130101; H01L 2224/05147
20130101; H01L 2924/00014 20130101; H01L 2224/05171 20130101; H01L
2924/00014 20130101; H01L 2224/05166 20130101; H01L 2924/01074
20130101; H01L 2224/05166 20130101; H01L 2924/013 20130101; H01L
2224/05184 20130101; H01L 2924/00014 20130101; H01L 2224/023
20130101; H01L 2924/0001 20130101 |
Class at
Publication: |
205/99 ;
204/275.1; 205/148; 205/135 |
International
Class: |
C25D 5/02 20060101
C25D005/02; C25D 17/02 20060101 C25D017/02; C25D 5/08 20060101
C25D005/08; C25D 21/06 20060101 C25D021/06 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 16, 2004 |
JP |
2004-365096 |
Feb 23, 2005 |
JP |
2005-047938 |
Claims
1-32. (canceled)
33. A plating device, comprising a plating tank which has an anode
therein and causing a plating solution to flow into the plating
tank and to jet upward to touch a surface-to-be-plated of a
substrate-to-be-plated while electrifying between the anode and the
substrate-to-be-plated, so that plating is performed, the plating
tank having a double structure including a first cylindrical cup
and a second cylindrical cup whose external diameter is smaller
than that of the first cylindrical cup, the first cylindrical cup
being provided with the anode and having a bottom provided with a
plating solution flowing-in port via which the plating solution
flows into the plating tank, a gap between side walls of the first
cylindrical cup and the second cylindrical cup serving as a plating
solution flowing-out port via which the plating solution having
flowed into the anode chamber flows out of the plating tank, the
second cylindrical cup having a bottom which is a partition
separating the anode from the substrate-to-be-plated, the plating
tank being divided into an anode chamber surrounded by the
partition and the first cylindrical cup and a
substrate-to-be-plated chamber surrounded by the partition and the
first cylindrical cup, and a plating solution jetting pipe being
provided so as to jet the plating solution to the
surface-to-be-plated of the substrate-to-be-plated, the plating
solution jetting pipe penetrating the partition and allowing a
laminar flow of the plating solution from the plating solution
flowing-in port to be divided into a laminar flow of the plating
solution to the first cylindrical cup and a laminar flow of the
plating solution to the second cylindrical cup.
34. The plating device as set forth in claim 33, wherein the
plating solution having flowed into the anode chamber does not flow
into the substrate-to-be-plated chamber.
35. The plating device as set forth in claim 33, wherein a portion
which separates the anode from the substrate-to-be-plated and which
includes the partition in the plating tank is partially or entirely
made of a permeation member which, when immersed in the plating
solution, allows ions in the plating solution to permeate the
permeation member.
36. The plating device as set forth in claim 35, wherein the
permeation member is a semipermeable membrane.
37. The plating device as set forth in claim 35, wherein the
permeation member includes an ion exchange membrane.
38. The plating device as set forth in claim 33, wherein the
partition has a thickness ranging from 50 to 200 .mu.m.
39. The plating device as set forth in claim 33, wherein the
partition includes a hydrocarbon cation exchange membrane.
40. The plating device as set forth in claim 33, further
comprising: a plating solution supplying source for storing a
plating solution to be supplied to the plating tank; plating
solution supplying means for supplying the plating solution stored
in the plating solution supplying source to the plating tank; and
plating solution filtering means for filtering the plating solution
supplied by the plating solution supplying means, the plating
solution stored in the plating solution supplying source being
supplied to the plating tank by the plating solution supplying
means and via the plating solution filtering means, and the plating
solution supplied to the plating tank being supplied again to the
plating solution supplying source.
41. The plating device as set forth in claim 33, wherein the
plating solution includes a copper component and is conductive.
42. The plating device as set forth in claim 33, wherein the
plating solution includes a copper component of not less than 14 g
and not more than 40 g per 1 lifter of the plating solution.
43. The plating device as set forth in claim 33, wherein the anode
is a soluble anode made of high phosphorous copper.
44. The plating device as set forth in claim 33, wherein the
substrate-to-be-plated is a semiconductor wafer.
45. A plating method for causing a plating solution to flow into a
plating tank and to jet upward to touch a surface-to-be-plated of a
substrate-to-be-plated while electrifying between an anode in the
plating tank and the substrate-to-be-plated, so that plating is
performed, the plating tank having a double structure including a
first cylindrical cup and a second cylindrical cup whose external
diameter is smaller than that of the first cylindrical cup, said
method comprising the steps of: dividing a laminar flow of the
plating solution into a laminar flow of the plating solution jetted
to the surface-to-be-plated and a laminar flow of the plating
solution flowing to a neighbor of the anode; and causing the
plating solution having flowed into the anode chamber to flow out
of the plating tank via a plating solution flowing-out port which
is a gap between side walls of the first cylindrical cup and the
second cylindrical cup.
46. A method for manufacturing a semiconductor device, comprising
the step (I) of causing a plating solution to flow into a plating
tank and to jet upward to touch a surface-to-be-plated of a
substrate-to-be-plated while electrifying between an anode and the
substrate-to-be-plated in the plating tank, so that plating is
performed, the plating tank having a double structure including a
first cylindrical cup and a second cylindrical cup whose external
diameter is smaller than that of the first cylindrical cup, in the
step (I), the anode and the surface-to-be-plated being positioned
to be separated from each other in the plating tank by a partition,
a flow of the plating solution being divided into a flow to the
surface-to-be-plated and a flow to a neighbor of the anode, and the
plating solution having flowed into the anode chamber is caused to
flow out of the plating tank via a plating solution flowing-out
port which is a gap between side walls of the first cylindrical cup
and the second cylindrical cup.
47. The method as set forth in claim 46, wherein in the step (I),
the plating solution having flowed to the neighbor of the anode
does not flow to the surface-to-be-plated.
48. The method as set forth in claim 46, wherein a portion which
separates the anode from the substrate-to-be-plated and which
includes the partition in the plating tank is partially or entirely
made of a permeation member which, when immersed in the plating
solution, allows ions in the plating solution to permeate the
permeation member.
49. The method as set forth in claim 48, wherein the permeation
member is a semipermeable membrane.
50. The method as set forth in claim 48, wherein the permeation
member includes an ion exchange membrane.
51. The method as set forth in claim 46, wherein the partition has
a thickness ranging from 50 to 200 .mu.m.
52. The method as set forth in claim 46, wherein the partition
includes a hydrocarbon cation exchange membrane.
53. The method as set forth in claim 46, wherein the step (I)
includes the sub-steps of: (i) supplying a plating solution stored
in a plating solution supplying source to the plating tank; (ii)
filtering the plating solution supplied in the sub-step (i); and
(iii) supplying again the plating solution supplied to the plating
tank to the plating solution supplying source.
54. The method as set forth in claim 46, wherein the plating
solution includes a copper component and is conductive.
55. The method as set forth in claim 46, wherein the plating
solution includes a copper component of not less than 14 g and not
more than 40 g per 1 litter of the plating solution.
56. The method as set forth in claim 46, wherein the anode is a
soluble anode made of high phosphorous copper.
57. The method as set forth in claim 46, wherein the
substrate-to-be-plated is a semiconductor wafer.
58. The method as set forth in claim 46, further comprising the
steps of: (II) forming a seed layer on the surface-to-be-plated;
(III) applying photoresist on a surface of the seed layer formed in
the step (II); and (IV) forming a pattern by exposing and
developing the photoresist, the steps (II) to (IV) being performed
before the step (I).
59. A semiconductor device, manufactured through a method as set
forth in claim 46.
Description
TECHNICAL FIELD
[0001] The present invention relates to a plating device, a plating
method, a semiconductor device, and a method for manufacturing a
semiconductor device. Specifically, the present invention relates
to: a plating device and a plating method allowing minute plating
for wiring to be formed on a surface to be plated; and a
semiconductor device and a method for manufacturing the
semiconductor device
BACKGROUND ART
[0002] Recently, metal plating is used for forming wiring on a
semiconductor wafer and the like. Examples of a conventional device
for metal plating include: a face-down type jet plating device; a
rack-type vertical plating device; and a face-up type jet plating
device.
[0003] As shown in FIG. 7, the face-down type jet plating device
includes: a wafer holder 2' for holding a semiconductor wafer 1'; a
cup 3'; a plating solution jetting pipe 4' for supplying a plating
solution into the cup 3'; and an anode 5'. The anode 5' is
generally made of high phosphorous copper. The anode 5' is provided
in the cup 3'. The cup 3' is provided with the wafer holder 2'. The
semiconductor wafer 1' is held by the wafer holder 2' so as to be
above the cup 3'. The plating solution jetting pipe 4' is provided
under the semiconductor wafer 1' in the face-down type jet plating
device. Consequently, a plating solution jetted out of the plating
solution jetting pipe 4' is supplied from under the semiconductor
wafer 1'. As a result, plating is performed on a surface to be
plated.
[0004] Note that, although not shown in FIG. 7, the face-down type
jet plating device includes: a plating solution tank for containing
the cup 3' therein; a plating solution storage tank for supplying a
plating solution; a pump for circulating the plating solution
through the plating device; a filter for filtering solid foreign
matters in the plating solution; and a pipe for connecting these
members.
[0005] In the face-down type jet plating device, a plating solution
in the plating solution storage tank is supplied by the pump to the
lower part of the cup 3' through the filter. The plating solution
is supplied from the lower part of the cup 3', flows through the
plating solution jetting pipe 4', and reaches, via the anode 5', a
surface of the semiconductor wafer 1 to be plated. Thereafter, the
plating solution leaks from a border of the upper part of the cup
3' (a space between the wafer holder 2' and the cup 3') to the
outside of the cup 3', is recovered into the plating solution tank,
and reflows into the plating solution storage tank.
[0006] Such face-down type jet plating device is disclosed in
Patent Document 1 for example. Patent Document 1 (Japanese
Unexamined Patent Publication No. 24307/2001 (Tokukai 2001-24307;
published on Jan. 26, 2001)) discloses a face-down type jet plating
device, which includes "a flowing-out port through which part of
the plating solution flowing in the plating tank is made to flow
out of the tank from a through-hole of the anode or the periphery
of the anode". Furthermore, a plating device in which an anode is
an insoluble electrode such as platinum is known.
[0007] As shown in FIG. 8, the rack-type vertical plating device
includes an anode 6'', a rack 24, and a plating tank 12. The anode
6'' is generally provided in an anode bag 13 made of a cloth having
internal raising. Examples of the anode 6'' include: spherical high
phosphorous copper in a titan basket; and a copper plate made of
high phosphorous copper. The rack 24 is a plate-shaped jig which
includes a power feeding section for the semiconductor wafer 1 and
which has a hole whose inside diameter is a bit smaller than the
semiconductor wafer 1. The plating tank 12 includes: a wafer
suppresser 25 which serves to fix the semiconductor wafer 1 to the
rack 24 as well as serves to insulate the back surface of the
semiconductor wafer 1; and a squeegee (not shown) for stirring a
plating solution.
[0008] Note that, although not shown in FIG. 8, the rack-type
vertical plating device includes: a plating solution tank; a
plating solution storage tank for supplying a plating solution; a
pump for circulating a plating solution through the plating device;
a filter for filtering solid foreign matters in the plating
solution; a pipe for connecting these members; and additional
devices.
[0009] The plating solution is supplied by the pump from the
storage tank to a flowing-in port 14 through the filter. Then, the
plating solution flows near the anode bag 13 including the anode 6
in the plating tank 12. Thereafter, the plating solution reaches a
surface of the semiconductor wafer 1 to be plated, flows from an
upper edge of the plating tank 12 to a dam 15, and reflows to the
plating solution storage tank through a return pipe (not shown)
which is a part of the dam 15. Such rack-type vertical plating
device is disclosed in Patent Document 2 (Japanese Unexamined
Patent Publication No. 87299/2000 (Tokukai 2000-87299; published on
Mar. 28, 2000)) for example.
[0010] A face-up type jet plating device is designed such that a
surface-to-be-plated of a semiconductor wafer is positioned to face
upward, an anode is positioned to face the surface-to-be-plated,
and a plating solution is supplied from above the semiconductor
wafer.
[0011] Such face-up type jet plating device is disclosed in Patent
Document 3 (Japanese Unexamined Patent Publication No. 49498/2001
(Tokukai 2001-49498; published on Feb. 20, 2001)) and Patent
Document 4 (Japanese Unexamined Patent Publication No. 24308/2001
(Tokukai 2001-24308; published on Jan. 26, 2001)). The face-up type
jet plating device disclosed in Patent Document 3 is designed such
that an ion exchange membrane or a porous neutral membrane is
provided at the bottom of an anode chamber and the anode chamber is
filled with a plating solution, thereby preventing a black film
from being dried and detached. The face-up type jet plating device
disclosed in Patent Document 4 is designed such that a porous
member having multiple pores is provided at the bottom of an anode
chamber.
[0012] Furthermore, a plating device having different structure
from the above plating devices is disclosed in Patent Document 5
(Japanese Unexamined Patent Publication No. 73889/2003 (Tokukai
2003-73889; published on Mar. 12, 2003)) for example. This plating
device is an electrolytic copper plating device for a semiconductor
wafer, in which a plating tank is divided into a cathode chamber
and an anode chamber by using a negative ion exchange membrane and
electrolytic copper plating is performed by using an insoluble
electrode as an anode.
[0013] In these plating devices, it is very important to form an
even laminar flow on a whole surface-to-be-plated of the
semiconductor wafer. Therefore, finish of plating is greatly
influenced by whether a laminar flow is made from a center to
peripheral of the surface-to-be-plated of the semiconductor
wafer.
[0014] A conventional face-up type jet plating device is designed
such that a semiconductor wafer is rotated so that a laminar flow
of a plating solution is formed, via a side flowing-in
port/flowing-out port, on a whole surface-to-be-plated of a
semiconductor wafer. For that reason, the conventional face-up type
jet plating device requires not only a mechanism for holding a
semiconductor wafer but also a mechanism for rotating the
semiconductor wafer, resulting in large-scale device.
[0015] On the other hand, a conventional face-down jet plating
device is so designed as to jet a plating solution from a central
part of a surface-to-be-plated of a semiconductor wafer, and
therefore the plating device and the semiconductor wafer are fixed
with each other, resulting in a simpler device.
[0016] However, the conventional face-down type jet plating device
has the following problem.
[0017] In the face-down type jet plating device, minute solid
foreign matters attach to a surface-to-be-plated, resulting in
deterioration in plating quality. It is attributable to a surface
of an anode in a route in which a plating solution is supplied by a
pump from a plating solution storage tank, is filtered by a filter,
is supplied from the bottom of a cup, flows near the anode, and
reaches a surface-to-be-plated of a semiconductor wafer. When the
anode includes high phosphorous copper, a black film is formed on
the surface of the anode. The black film is made of a monovalent
copper complex (Cu.sup.+) including chlorine (Cl) and phosphorous
(P). The black film is made as a result of combination between
chlorine and phosphorous and monovalent copper ions generated by
anode melting.
[0018] The black film can suppress generation of slime by
suppressing disproportionation of copper which is indicated by the
following formula (1).
2Cu.sup.+.fwdarw.Cu+Cu.sup.2+ (1)
[0019] However, the black film once formed tends to be detached
from the surface of the anode. The detached minute black film is
conveyed along with a flowing plating solution to the
surface-to-be-plated of the semiconductor wafer. Consequently, the
black film attaches to the plated surface of the semiconductor
wafer.
[0020] The above problem of the black film can be prevented by
using an insoluble electrode as an anode. However, at that time, an
additive in the plating solution is subjected to oxidative
decomposition. Consequently, more amount of the plating solution is
consumed or a decomposition product due to the oxidative
decomposition contaminates the plating solution.
[0021] On the other hand, in the conventional rack-type vertical
plating device, an anode including high phosphorous copper is
provided in an anode bag made of a cloth having internal raising.
Consequently, it is possible to prevent solid foreign matters
derived from a black film from attaching to a semiconductor wafer.
However, such vertical plating device requires fixing a
semiconductor wafer to a rack so that the semiconductor wafer is
held in a plating tank. This fixation drops productivity and
plating quality and prevents automation.
DISCLOSURE OF INVENTION
[0022] The present invention was made in view of the foregoing
problems. An object of the present invention is to provide: a
plating device and a plating method each of which prevents minute
solid foreign matters derived from a black film etc. from
deteriorating plating quality, without impairing operativity in a
face-down type jet plating device; and a semiconductor device and a
method for manufacturing the semiconductor device.
[0023] In order to solve the foregoing problems, the plating device
of the present invention is a plating device, including a plating
tank which has an anode therein and causing a plating solution to
flow into the plating tank and to jet upward to touch a
surface-to-be-plated of a substrate-to-be-plated while electrifying
between the anode and the substrate-to-be-plated, so that plating
is performed, the plating tank including a partition between the
substrate-to-be-plated and the anode, the partition separating the
anode from the substrate-to-be-plated, and the plating tank being
divided into a substrate-to-be-plated chamber and an anode
chamber.
[0024] The plating device of the present invention causes the
plating solution to jet upward to touch the surface-to-be-plated of
the substrate-to-be-plated while electrifying between the anode and
the substrate-to-be-plated, so that plating is performed. That is,
the plating device of the present invention performs plating in a
face-down manner.
[0025] Note that, the "substrate-to-be-plated chamber" is a space
including the substrate-to-be-plated out of two areas separated by
the partition. The "anode chamber" is a space including the anode
out of the two areas separated by the partition.
[0026] Further, with the arrangement, the anode and the
substrate-to-be-plated are separated from each other by the
partition, and the plating tank is divided into the
substrate-to-be-plated chamber and the anode chamber. Consequently,
it is possible to prevent particles etc. derived from the anode
from contaminating the plated surface.
[0027] As described above, with the arrangement, it is possible to
provide a plating device capable of preventing deterioration in
plating quality due to minute solid foreign matters derived from a
black film etc., without impairing operativity.
[0028] In order to solve the foregoing problems, the plating method
of the present invention is a plating method for causing a plating
solution to flow into a plating tank and jet upward to touch a
surface-to-be-plated of a substrate-to-be-plated while electrifying
between an anode in the plating tank and the
substrate-to-be-plated, so that plating is performed, said method
comprising the step of dividing a laminar flow of the plating
solution into a laminar flow of the plating solution jetted to the
surface-to-be-plated and a laminar flow of the plating solution
flowing to a neighbor of the anode.
[0029] With the arrangement, plating is performed while dividing a
laminar flow of the plating solution into a laminar flow of the
plating solution jetted to the surface-to-be-plated and a laminar
flow of the plating solution flowing to a neighbor of the anode.
Consequently, it is possible to prevent particles etc. derived from
the anode from contaminating the plated surface. As a result, it is
possible to prevent deterioration in plating quality due to minute
solid foreign matters derived from a black film etc.
[0030] In order to solve the foregoing problems, the method of the
present invention for manufacturing a semiconductor device is a
method, comprising the step of causing a plating solution to flow
into a plating tank and to jet upward to touch a
surface-to-be-plated of a substrate-to-be-plated while electrifying
between an anode and the substrate-to-be-plated in the plating
tank, so that plating is performed, in the step, the anode and the
surface-to-be-plated are positioned to be separated from each other
in the plating tank by a partition.
[0031] With the arrangement, in the step, plating is performed
while the anode and the surface-to-be-plated are separated from
each other in the plating tank by the partition. Consequently, it
is possible to prevent particles etc. derived from the anode from
contaminating the plated surface.
[0032] As a result, with the arrangement, it is possible to obtain
a semiconductor device which is free from minute solid foreign
matters derived from a black film etc. on the surface of the anode
and which has plated wiring with high quality.
[0033] In order to solve the foregoing problems, the semiconductor
device of the present invention is manufactured through the method
for manufacturing a semiconductor device.
[0034] With the arrangement, the semiconductor device is
manufactured through the method. Consequently, it is possible to
provide a semiconductor device which is free from minute solid
foreign matters derived from a black film etc. on the surface of
the anode and which has plated wiring with high quality.
[0035] Additional objects, features, and strengths of the present
invention will be made clear by the description below.
BRIEF DESCRIPTION OF DRAWINGS
[0036] FIG. 1 is a cross sectional drawing schematically
illustrating a structure of a plating tank provided in a plating
device of an embodiment of the present invention.
[0037] FIG. 2 is a cross sectional drawing illustrating an example
of a structure of a wafer holder of the plating tank.
[0038] FIG. 3 are drawings illustrating a structure of an area
surrounded by an internal cylinder and a partition. The upper
drawing is a top plan drawing seen from a surface of a
semiconductor wafer to be plated. The lower drawing is a cross
sectional drawing.
[0039] FIG. 4 is a drawing schematically illustrating a structure
of a plating device of an embodiment of the present invention.
[0040] FIG. 5 is an explanatory drawing of a structure of an ion
exchange membrane.
[0041] FIG. 6 is an explanatory drawing of permselectivity of the
ion exchange membrane.
[0042] FIG. 7 is a cross sectional drawing schematically
illustrating a conventional face-down type jetting plating
device.
[0043] FIG. 8 is a cross sectional drawing schematically
illustrating a conventional rack-type vertical plating device.
[0044] FIG. 9 is a drawing schematically illustrating a structure
of a semiconductor wafer used in the present invention.
[0045] FIG. 10(a) is a plan drawing schematically illustrating a
semiconductor chip formed on a semiconductor wafer after a plating
step.
[0046] FIG. 10(b) is a cross sectional drawing schematically
illustrating the semiconductor chip.
[0047] FIG. 11(a) is a cross sectional drawing schematically
illustrating a structure of a part of a semiconductor chip before a
seed layer forming step of a method of the present invention for
manufacturing a semiconductor wafer.
[0048] FIG. 11(b) is a cross sectional drawing schematically
illustrating a structure of a part of a semiconductor chip after
the seed layer forming step of the method of the present invention
for manufacturing a semiconductor wafer.
[0049] FIG. 11(c) is a cross sectional drawing schematically
illustrating a structure of a part of a semiconductor chip after a
photoresist applying step of the method of the present invention
for manufacturing a semiconductor wafer.
[0050] FIG. 11(d) is a cross sectional drawing schematically
illustrating a structure of a part of a semiconductor chip after a
photoresist pattern forming step of the method of the present
invention for manufacturing a semiconductor wafer.
[0051] FIG. 11(e) is a cross sectional drawing schematically
illustrating a structure of a part of a semiconductor chip after a
plating step of the method of the present invention for
manufacturing a semiconductor wafer.
[0052] FIG. 11(f) is a cross sectional drawing schematically
illustrating a structure of a part of a semiconductor chip after a
stripping step of the method of the present invention for
manufacturing a semiconductor wafer.
[0053] FIG. 11(g) is a cross sectional drawing schematically
illustrating a structure of a part of a semiconductor chip after an
etching step of the method of the present invention for
manufacturing a semiconductor wafer.
[0054] FIG. 12(a) is a cross sectional drawing schematically
illustrating a part of a semiconductor chip having a wiring plating
layer thereon before an overcoat layer forming step in an external
connection terminal providing step of providing a semiconductor
wafer having the wiring plating layer thereon with an external
connection terminal.
[0055] FIG. 12(b) is a cross sectional drawing schematically
illustrating a part of a semiconductor chip after the overcoat
layer forming step in the external connection terminal providing
step.
[0056] FIG. 12(c) is a cross sectional drawing schematically
illustrating a part of a semiconductor chip after an overcoat layer
pattern forming step in the external connection terminal providing
step.
[0057] FIG. 12(d) is a cross sectional drawing schematically
illustrating a part of a semiconductor chip after an external
connection terminal forming step in the external connection
terminal providing step.
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1
[0058] With reference to FIGS. 1 to 6, the following explains an
embodiment of the present invention.
[0059] FIG. 1 is a cross sectional drawing schematically
illustrating a structure of a plating tank provided in a plating
device of the present embodiment. As shown in FIG. 1, a plating
tank 100 includes: a wafer holder 2 for holding a semiconductor
wafer (substrate-to-be-plated) 1; a cup 3; a plating solution
jetting pipe 4; an anode 5; a supporter 6 for supporting the anode
5; and a partition 7. The cup 3 includes an internal cylinder 31
and an external cylinder 32.
[0060] The internal cylinder (second cylindrical cup) 31 and the
external cylinder (first cylindrical cup) 32 are cups each having
substantially a cylindrical shape, with its upper end open. The
diameter of the internal cylinder 31 is smaller than the diameter
of the external cylinder 32. The external cylinder 32 has at its
lowest central part a plating solution flowing-in port E through
which a plating solution flows in.
[0061] The internal cylinder 31 has at its bottom the partition 7
having a donut shape, which separates the internal cylinder 31 from
the external cylinder 32. That is, the partition 7 is provided
between a surface-to-be-plated W of the semiconductor wafer 1 and
the anode 5, and separates the anode 5 from the semiconductor wafer
1. Consequently, the plating tank 100 is divided into a
substrate-to-be-plated chamber and an anode chamber. The
"substrate-to-be-plate chamber" means a space surrounded by the
internal cylinder 31 and the partition 7. The "anode chamber" means
a space surrounded by the external cylinder 32 and the partition
7.
[0062] As shown in FIG. 1, the plating solution jetting pipe 4 is
provided so as to penetrate a hole at the center of the partition
7. The supporter 6 is connected with the external cylinder 32 and
has a structure through which a plating solution flows. The anode 5
is provided on the supporter 6. The anode 5 is positioned above the
lower end of the plating solution jetting pipe 4.
[0063] The partition 7 includes hydrocarbon cation exchange
membrane. However, the partition 7 is not particularly limited as
long as it includes a permeation member allowing metal ions in a
plating solution flowing near the anode 5 and the supporter 6, that
is, flowing in the anode chamber, to permeate the permeation
member. For example, the partition 7 may include an ion exchange
membrane, a neutral membrane, a porous ceramics, etc. In the case
where the partition 7 includes a hydrocarbon cation exchange
membrane, examples of the hydrocarbon cation exchange membrane
include SELEMION.RTM. (manufactured by ASAHI GLASS ENGENEERING Co.,
Ltd., hydrocarbon cation exchange membrane) and NEOSEPTA CM-1.RTM.
(manufactured by ASTOM Corporation, hydrocarbon cation exchange
membrane). The structure of the partition 7 is specifically
explained later.
[0064] Furthermore, the partition 7 may allow not only metal ions
but also positive ions (ions having the same electric nature as
metal ions) which are components of an additive to permeate the
partition 7.
[0065] The plating solution jetting pipe 4 and the supporter 6 are
made of polypropylene. The anode 5 is a soluble anode made of high
phosphorous copper. However, the plating solution jetting pipe 4
and the supporter 6 are not particularly limited as long as they
have dimensional stability and are resistive to a plating solution.
For example, the plating solution jetting pipe 4 and the supporter
6 may be made of hard vinyl chloride.
[0066] The dimension of the semiconductor wafer 1 applicable to the
present invention may be set according to the dimension of each
member of the plating tank 100. For example, the diameter of the
semiconductor wafer 1 may range from approximately 100 mm to 500
mm. More specifically, the diameter may be approximately 150
mm.
[0067] The internal cylinder 31 has a bottom to which the partition
7 is attached and fixed. The internal diameter of the internal
cylinder 31 should be smaller than the surface-to-be-plated W of
the semiconductor wafer 1.
[0068] In this way, when the internal diameter of the internal
cylinder 31 is smaller than the surface-to-be-plated W of the
semiconductor wafer 1, a plating solution jetted from the plating
solution jetting pipe 4 is directed to the surface-to-be-plated W
of the semiconductor wafer 1 without being exposed to the air.
Consequently, the plating device of the present invention allows
plating without exposure to the air. This prevents contamination of
a plating solution due to floating foreign matters in the air,
evaporation of the plating solution, and contamination of
surrounding environments due to the evaporation or the mist of the
plating solution.
[0069] The height of the internal cylinder 31 may range from 50 mm
to 100 mm. Here, the dimension of the internal cylinder 31 is as
follows: the external diameter is 150 mm, the internal diameter is
140 mm, the thickness is 5 mm, and the height is 80 mm. The
internal cylinder 31 has a cylindrical shape.
[0070] As mentioned later, the height of the external cylinder 32
is not particularly limited as long as the height allows the
plating solution from the plating solution jetting pipe 4 to
sufficiently cover the surface-to-be-plated W from its central part
to its peripheral part and the upper end of the external cylinder
32 is lower than the upper end of the internal cylinder. Here, the
internal diameter of the external cylinder 32 is 160 mm. The
external cylinder 32 is designed such that the height of the
external cylinder 32 allows the plating solution from the plating
solution jetting pipe 4 to sufficiently reach the peripheral
surface of the semiconductor wafer 1 and the upper end of the
external cylinder 32 is lower than the upper end of the internal
cylinder 31.
[0071] The external diameter of the internal cylinder 31 is 150 mm
and the internal diameter of the external cylinder 32 is 160 mm.
The gap (plating solution flowing-out port) between the internal
cylinder 31 and the external cylinder 32 is 5 mm. However, the gap
between the internal cylinder 31 and the external cylinder 32 is
not limited to this. By narrowing the gap between the internal
cylinder 31 and the external cylinder 32, it is possible to
increase a difference between the heights of the upper ends of the
internal cylinder 31 and the external cylinder 32, which will be
mentioned later. By narrowing the gap between the internal cylinder
31 and the external cylinder 32, resistance (pressure) increases
due to viscosity of the plating solution. Consequently, even when
the internal cylinder is made to have higher height, the plating
solution reaches to the upper end of the internal cylinder. As a
result, flexibility in designing the plating device increases.
[0072] The partition 7 has a donut shape whose external diameter is
140 mm and internal diameter is 40 mm. The external periphery of
the partition 7 is attached to the internal cylinder 31 and the
internal periphery of the partition 7 is attached to the plating
solution jetting pipe 4, so that the partition 7 is fixed. However,
the dimension of the partition 7 is not limited to this.
[0073] The supporter 6 is provided between the external cylinder 32
and the plating solution jetting pipe 4. The supporter 6 is
provided above the bottom of the external cylinder 32 so that the
gap between the supporter 6 and the bottom of the external cylinder
32 ranges from at least 5 mm to 20 mm. The supporter 6 has multiple
penetrating holes in a vertical direction.
[0074] The thickness of the partition 7 preferably ranges from 50
.mu.m to 200 .mu.m, more preferably ranges from 50 .mu.m to 100
.mu.m. When the thickness of the partition 7 is smaller than 50
.mu.m, an electric current for plating is required more than
necessary, which deteriorates efficiency in plating. When the
thickness of the partition 7 is larger than 200 .mu.m, a black
defective appearance called "discoloration" is seen on the plated
surface.
[0075] Attachment of the partition 7 to the internal cylinder 31
makes a cup member whose thickness is 2 to 10 mm and whose opening
is a circle with a diameter of 0.2 to 9 mm or a square, a
rectangle, or a quadrangle with a side of 0.2 to 9 mm. The
partition 7 (SELEMION partition) is not necessarily a perfect
circle. The partition 7 may be a quadrangle at the extreme.
[0076] The dimension of the anode 5 made of high phosphorous copper
is as follows: the external diameter is 150 mm, the internal
diameter is 50 mm, and the thickness is 8 m. However, the dimension
of the anode 5 is not limited to this. The dimension may be any
value as long as the dimension does not prevent the plating
solution from flowing through the gap between the supporter 6 and
the partition 7 and the gap between the external cylinder 32 and
the anode 5. High phosphorous copper in the anode 5 is not
particularly limited as long as it includes 0.04 to 0.06% of
phosphorous.
[0077] The plating solution jetting pipe 4 penetrates the partition
7 and extends above the partition 7 by 20 mm. However, the plating
solution jetting pipe 4 is not limited to this as long as the
plating solution jetting pipe 4 extends from under the anode 5 to
the partition 7.
[0078] The dimensions and other factors of the semiconductor wafer
1, the cup 3 (the internal cylinder 31 and the external cylinder
32), the plating solution jetting pipe 4, the anode 5, the
supporter 6, and the partition 7 in the plating tank 100 were
explained above. The dimensions of the members in the plating tank
100 may be set according to the dimension of the plating tank 100
or the dimension of the semiconductor wafer 1 applied to the
plating tank 100.
[0079] With reference to FIG. 2, the following specifically
explains a structure of the wafer holder 2 for holding the
semiconductor wafer 1. FIG. 2 is a cross sectional drawing
illustrating an example of the structure of the wafer holder 2 in
the plating tank 100. As shown in FIG. 2, the wafer holder 2
includes an O ring 21, contact members 22, and a wafer holding ring
23. The wafer holding ring 23 is held by a supporter (not shown) so
that there exists a predetermined gap between the upper part of the
internal cylinder 31 and the wafer holding ring 23. The O ring 21
and the contact members 22 are provided on the wafer holding ring
23 and keep attachment to the semiconductor wafer 1 to be held.
[0080] Three contact members 22 are provided on a peripheral part
of the semiconductor wafer 1 with the same distance among them.
However, the number of the contact members 22 is not limited to
three. Four or more contact members 22 may be provided on the
peripheral part of the semiconductor wafer 1 with the same distance
between them. Furthermore, the contact member 22 may attach to the
whole peripheral part of the semiconductor wafer 1.
[0081] The internal diameter of the wafer holding ring 23 is 140
mm, but not limited to this. The wafer holding ring 23 does not
necessarily have a circular shape. The wafer holding ring 23 may be
integral with a main body of the device.
[0082] The following explains the members of the wafer holder
2.
[0083] The O ring 21 is not particularly limited as long as it
keeps attachment to the semiconductor wafer 1 and is resistive to a
plating solution. The O ring 21 may be made of silicone gum for
example. A specific example is Viton.RTM. (manufactured by Dupont
Dow Elastomers Japan).
[0084] The contact member 22 is not particularly limited as long as
it keeps attachment to the semiconductor wafer 1, it is conductive,
and it is resistive to a used plating solution. The contact member
22 may be made of titan with metal plating for example.
Specifically, examples of the contact member 22 include titan with
platinum plating, titan with gold plating, resin with gold plating
etc, and combinations thereof.
[0085] The wafer holding ring 23 is not particularly limited as
long as it has dimensional stability and is resistive to a plating
solution. The wafer holding ring 23 may be made of hard vinyl
chloride or polypropylene for example.
[0086] With reference to FIG. 3, the following explains an example
of the structure of the partition 7 provided between the
surface-to-be-plated W of the semiconductor wafer 1 and the anode
5. FIG. 3 illustrates the structure of an area
(substrate-to-be-plated chamber) surrounded by the internal
cylinder 31 and the partition 7 in the plating tank 100. The upper
drawing is a top plan drawing seen from the surface-to-be-plated W
of the semiconductor wafer 1. The lower drawing is a cross
sectional drawing.
[0087] As illustrated in FIG. 3, the partition 7 has a donut shape
seen from the surface-to-be-plated W. The plating solution jetting
pipe 4 penetrates the central part of the partition 7. The
periphery of the partition 7 is fixed with the bottom of the
internal cylinder 31.
[0088] The partition 7 includes a semipermeable membrane
(permeation member) 71 and semipermeable membrane supporters 72 and
73. The partition 7 is made by the semipermeable membrane
supporters 72 and 73 holding the semipermeable membrane 71 between
them. The semipermeable membrane supporter 72 is positioned at the
anode 5 side and the semipermeable membrane supporter 73 is
positioned at the surface-to-be-plated W side of the semiconductor
wafer 1.
[0089] By electrifying between the semiconductor wafer 1 and the
anode 5, the plating solution having flowed to the anode 5
permeates the semipermeable membrane supporter 72. Metal ions of
the plating solution permeate the semipermeable membrane 71. The
metal ions permeate the semipermeable membrane supporter 73 and
flows toward the surface-to-be-plated W (into the
substrate-to-be-plated chamber) of the semiconductor wafer 1. At
that time, the metal ions of the plating solution permeate the
semipermeable membrane 71, but particles of the plating solution do
not permeate the semipermeable membrane 71. Consequently, the
partition 7 allows for separation of metal ions and particles in
the plating solution. This prevents particles due to the anode 5
from contaminating the surface-to-be-plated.
[0090] The semipermeable membrane 71 is not particularly limited as
long as metal ions of the metal solution can permeate the
semipermeable membrane 71 when the semipermeable membrane 71 is
immersed in the plating solution. Examples of the semipermeable
membrane 71 include a hydrocarbon cation exchange membrane, a
neutral membrane, and porous ceramics. In the case where the
semipermeable membrane 71 is a hydrocarbon cation exchange
membrane, specific examples of the semipermeable membrane 71
include SELEMION.RTM. (manufactured by ASAHI GLASS ENGENEERING Co.,
Ltd., hydrocarbon cation exchange membrane) and NEOSEPTA CM-1.RTM.
(manufactured by ASTOM Corporation, hydrocarbon cation exchange
membrane).
[0091] The semipermeable membrane supporters 72 and 73 are not
particularly limited as long as they are permeated by a plating
solution, they have dimensional stability, and they are resistive
to the plating solution. Examples of materials of the semipermeable
membrane supporters 72 and 73 include polypropylene and hard vinyl
chloride.
[0092] The following explains a structure of the semipermeable
membrane 71 using an ion exchange membrane including an ion
exchange membrane as an example. FIG. 5 is an explanatory drawing
of a structure of the ion exchange membrane. FIG. 6 is an
explanatory drawing of permselectivity of the ion exchange
membrane.
[0093] As illustrated in FIG. 5, the "ion exchange membrane" is a
membrane which selectively allows ions to permeate it. The ion
exchange membrane is roughly classified into a positive ion
exchange membrane and a negative ion exchange membrane. As
illustrated in FIG. 5, when the positive ion exchange membrane
immersed in the plating solution is electrified, the positive ion
exchange membrane selectively allows positive ions (M.sup.+) to
permeate it and does not allow negative ions (B.sup.-) to permeate
it.
[0094] As illustrated in FIG. 6, substituents with negative
electric charge are fixed with the positive ion exchange membrane.
Consequently, the negative ions (B.sup.-) are repulsed by the
substituents with negative electric charge and accordingly cannot
permeate the positive ion exchange membrane. On the other hand, the
positive ions (M.sup.+) are not repulsed by the substituents with
negative electric charge and accordingly can permeate the positive
ion exchange membrane. That is, only the positive ions (M.sup.+)
can permeate the positive ion exchange membrane.
[0095] In contrast, the negative ion exchange membrane has the
opposite function. Selective permeation in these ion exchange
membranes is caused by electric energy of an electrodialyzer. The
electric energy of the electrodialyzer is not particularly limited.
The electric energy may be derived from a direct current, a pulse
current, or an alternative current.
[0096] With reference to FIG. 4, the following explains a structure
of a plating device of the present invention. FIG. 4 is a drawing
schematically illustrating a structure of the plating device of the
present invention.
[0097] As illustrated in FIG. 4, the plating device of the present
invention includes: the plating tank 100; a plating solution tank 8
for containing the plating tank 100 therein; the plating solution
storage tank 9 for supplying a plating solution; a pump 10 for
circulating the plating solution through the plating device; a
filter 11 for filtering solid foreign matters in the plating
solution; and a pipe T connecting these members.
[0098] In the plating device of the present invention, a plating
solution in the plating solution storage tank 9 is supplied by the
pump 10, via the filter 11, to a plating solution flowing-in port E
provided at the lower part of the plating tank 100. The plating
solution is supplied from the plating solution flowing-in port E,
flows through the plating solution jetting pipe 4, and reaches the
surface-to-be-plated W of the semiconductor wafer 1. Thereafter,
the plating solution leaks from a border of the upper part of the
internal cylinder 31 (a space between the wafer holder 2 and the
internal cylinder 31) to the outside of the plating tank 100, is
recovered into the plating solution tank 8, and returns to the
plating solution storage tank 9.
[0099] The plating solution tank 8, the plating solution storage
tank 9, and the pipe T are not particularly limited as long as they
have dimensional stability and are resistive to a used plating
solution. Examples of materials of them include hard vinyl chloride
and polypropylene.
[0100] Further, the pump 10 is not particularly limited as long as
it is resistive to a used plating solution and causes the plating
solution to flow without having a bad influence on the plating
solution. Examples of the pump 10 include magnet pump MD-70R
(manufactured by IWAKI CO., LTD.) and magnet pumps MD-30R and
MD-100R (manufactured by IWAKI CO., LTD.). The material of the pump
10 is not particularly limited as long as it has dimensional
stability and is resistive to a used plating solution. The pump 10
may be made of hard vinyl chloride or polypropylene for
example.
[0101] The filter 11 is not particularly limited as long as the
filter 11 has 100% collection efficiency of particles whose grain
size corresponds to approximately 1/2 of the minimum gap of a
target plating pattern, the filter 11 is resistive to a used
plating solution, and the filter 11 allows the plating solution to
flow without a bad influence on the plating solution. Examples of
the filter 11 include: polypropylene cartridge filter HDCII (J012;
100% collection efficiency of 1.2 .mu.m size particles)
manufactured by Japan Pall Corporation; polypropylene cartridge
filter HDCII (J006; 100% collection efficiency of 1.0 .mu.m size
particles) manufactured by Japan Pall Corporation; a Teflon.RTM.
filter; and a hollow fiber membrane filter. Material of the filter
11 is not particularly limited as long as the material has
dimensional stability and is resistive to a used plating solution.
Examples of the material include hard vinyl chloride and
polypropylene.
[0102] Although not shown in FIG. 4, a valve, a flow meter, an air
vent pipe etc. are connected in the course of a pipe T. A flow of a
plating solution can be controlled by a controller (not shown). A
voltage can be applied between a surface-to-be-plated and the anode
5 by a power source for plating (not shown).
[0103] As an example of plating in the plating device of the
present invention, the following details a case where copper
plating is performed on the surface-to-be-plated W of the
semiconductor wafer 1.
[0104] The semiconductor wafer 1 is placed on the wafer holder 2 so
that the surface-to-be-plated W of the semiconductor wafer 1 faces
downward. The semiconductor wafer 1 is attached to the O ring 21
and the contact member 22 by a wafer suppressor (not shown).
[0105] As shown in FIG. 4, a plating solution in the plating
solution storage tank 9 is supplied to the filter 11 by the pump 10
controlled by the controller (not shown). The filter 11 removes,
from the plating solution, foreign matters which are larger than
mesh size of the filter 11. The plating solution flows into the
plating solution flowing-in port E of the plating tank 100 through
the pipe. The plating solution having flowed from the plating
solution flowing-in port E at the bottom of the external cylinder
32 of the cup 3 flows into the internal cylinder 31 through the
plating solution jetting pipe 4. The plating solution is a copper
plating solution including an additive and copper which is
equivalent to approximately 25 g/L of copper metal (MICROFAB Cu200;
manufactured by Electroplating Engineers of Japan).
[0106] A part of the plating solution having flowed into the
plating solution flowing-in port E flows into a space between the
bottom of the external cylinder 32 and the supporter 6. The plating
solution flowing in the gap between the bottom of the external
cylinder 32 and the supporter 6 (hereinafter referred to as the
plating solution flowing in the anode chamber) flows through
penetrating holes in the supporter 6, flows upward while enveloping
the anode 5, and flows along the partition 7 toward the outer
periphery. The anode 5 in the plating device includes high
phosphorous copper whose phosphorous is approximately 0.04 to
0.06%.
[0107] On the other hand, the plating solution flowing into the
internal cylinder 31 via the plating solution jetting pipe 4
(hereinafter referred to as the plating solution flowing into the
surface-to-be-plated chamber) has a higher pressure due to kinetic
energy of the plating solution and due to a resistance which is
caused when the plating solution flowing in the anode chamber flows
out of the plating tank 100 through the gap (plating solution
flowing-out port) between the internal cylinder 31 and the external
cylinder 32. Consequently, a liquid level of the plating solution
having flowed in the substrate-to-be-plated chamber reaches the
surface-to-be-plated W of the semiconductor wafer 1. Then, the
plating solution flows toward the periphery of the
surface-to-be-plated W of the semiconductor wafer 1. Then, the
solution flows out of the plating tank 100 via the gap between the
internal cylinder 31 and the wafer holding ring 23.
[0108] The plating solution having flowed out of the plating tank
100 via the gap between the internal cylinder 31 and the external
cylinder 32 and the plating solution having flowed out of the
plating tank 100 via the gap between the internal cylinder 31 and
the wafer holding ring 23 are mixed with each other and are
supplied to the plating solution tank 8. The plating solution in
the plating solution tank 8 returns to the plating solution storage
tank 9 by a vertical interval.
[0109] At that time, a voltage is applied between the anode 5 and
the surface-to-be-plated W, serving as a cathode, of the
semiconductor wafer 1 while controlling an electric current by the
power source for plating (not shown). Consequently, an additive in
the plating solution works in a predetermined manner on the surface
of the anode 5, resulting in generation of copper ions. The
generated metal ions permeate the partition 7 and reach, via the
inside of the internal cylinder 31, the surface of the
semiconductor wafer 1 serving as a cathode. The additive in the
plating solution works in a predetermined manner on the
surface-to-be-plated W of the semiconductor wafer 1 and accordingly
copper ions are deposited as copper and the surface-to-be-plated W
is plated with copper.
[0110] In the plating device of the present invention, the flow
rate of the plating solution supplied by the pump 10 to the filter
11 can be set according to the dimension of the semiconductor wafer
1 or to the dimension of the plating tank 100. Specifically, the
flow rate is approximately 20 L per minute or approximately 2 to 20
L per minute.
[0111] Furthermore, a voltage to be applied between the
surface-to-be-plated W and the anode 5 and a time for applying a
voltage can be set according to the dimension of the semiconductor
wafer 1 or to the dimension of the plating tank 100. Specifically,
a voltage is applied for 25 minutes while controlling an electric
current so that current density of the surface-to-be-plated W is 20
mA per 1 cm.sup.2.
[0112] The internal cylinder 31 is filled with the plating solution
which has passed through the filter 11 and has removed solid
foreign matters larger than mesh size of the filter. The plating
solution having flowed into the anode chamber cannot flow into the
internal cylinder 31 due to the partition 7 and the flow of the
plating solution. Only copper ions in the plating solution permeate
the partition 7 and reach the inside of the internal cylinder 31.
Consequently, minute solid foreign matters derived from black film
etc. on the surface of the anode 5 do not attach the plated
surface. Furthermore, unlike conventional examples, it is
unnecessary to use an insoluble electrode so as to prevent
attachment of minute solid foreign matters derived from a black
film etc. Consequently, it is possible to obtain high-quality
plating without an increase in consumption of an additive due to
oxidative decomposition of the additive in the plating solution and
without deterioration in plating quality due to contamination of
the plating solution by decomposition product.
[0113] In the above example, a copper plating solution (MICROFAB
Cu200; manufactured by Electroplating Engineers of Japan) was used.
However, a plating solution in the present embodiment is not
limited to this as long as it allows a desired effect.
[0114] Explanations were made above as to a case where the
partition 7 in the plating device of the present invention is
partially or entirely made of a permeation member which allows
metal ions in the plating solution to permeate the permeation
member. However, the plating device is not limited to this case.
The plating device of the present invention may be arranged so
that: the internal cylinder 31 whose bottom is the partition 7 has
a portion separating the surface-to-be-plated W of the
semiconductor wafer 1 from the anode 5 and the portion is partially
or entirely made of a permeation member which allows metal ions in
the plating solution to permeate the permeation member. That is,
the substrate-to-be-plated chamber has a portion separating the
anode from the substrate-to-be-plated and the portion is partially
or entirely made of a permeation member which allows metal ions in
the plating solution to permeate the permeation member. For
example, the internal cylinder 31 may be partially or entirely made
of such permeation member.
[0115] In the face-down type plating device, the plating solution
flowing upward from the lower part of the cup flows out of the cup
through the gap between the cup and the wafer holder. At that time,
a rise of a liquid level by increasing a flow rate of the plating
solution is combined with surface tension (hydrophilicity) of the
plating solution with the semiconductor wafer, allowing the plating
solution to flow toward the periphery of the cup and flow out of
the cup, together with wetting the surface-to-be-plated of the
semiconductor wafer which is positioned above the gap.
[0116] Here, it is very important to form an even flow of the
plating solution on a whole surface-to-be-plated of the
semiconductor wafer. Therefore, finish of plating is greatly
influenced by whether a laminar flow is made from a center to
peripheral of the surface.
[0117] In a conventional face-down type plating device, providing a
partition between an anode and a semiconductor wafer would prevent
a plating solution from touching the wafer, which would make
plating impossible.
[0118] In order to solve the problem, the present invention is
designed such that: the structure of a cup is changed from a
conventional structure to a double structure including an internal
cylinder and an external cylinder, a plating solution jetting pipe
is provided so as to penetrate a partition from under an anode
toward a wafer, the port of the pipe divides a plating solution
into two: a solution which reaches the surface of the wafer and
takes part in plating the surface; and a solution which flows near
the anode and is drained out of the cup. This allows the plating
solution to flow on the surface of the wafer from the center of the
wafer with enough flow speed and flow rate and to form a laminar
flow, while allowing the plating solution to flow near the anode,
to flow along the partition, and to flow out of the cup.
[0119] A conventional face-up type jet plating device is designed
such that a wafer is rotated so that a flow of a plating solution
is evenly formed, via a side flowing-in port/flowing-out port, on a
whole surface of a semiconductor wafer to be plated. For that
reason, the conventional face-up type jet plating device requires
not only a mechanism for holding a semiconductor wafer but also a
mechanism for rotating the semiconductor wafer, resulting in a
large-scale device.
[0120] In contrast, the plating device of the present invention can
flow the plating solution from the center of the semiconductor
wafer. Consequently, the plating tank and the semiconductor wafer
are fixed with each other, realizing a simpler structure.
[0121] The plating device of the present invention may be expressed
as a face-down type jet plating device for plating a substrate,
wherein an anode and a surface-to-be-plated are positioned to be
separated from each other in a plating cup. The plating device
supplies a plating solution into the plating cup.
[0122] As a result, in the plating method in which the plating
device causes the plating solution to flow into the plating cup and
to touch the surface-to-be-plated while electrifying between the
anode in the plating cup and the surface-to-be-plated, the plating
solution having flowed to the neighbor of the anode in the plating
cup does not reach the surface-to-be-plated by the flow of the
plating solution. Alternatively, in the method, the plating
solution having flowed into the neighbor of the anode in the
plating cup can flow out of the cup without reaching the
surface-to-be-plated.
[0123] The plating device is designed such that: a structure for
separating the anode from the surface-to-be-plated in the plating
cup is partially or entirely made of a material which, when
immersed in an electrolytic solution, allows ions to permeate the
material. Examples of the material include a semipermeable
membrane, an ion exchange membrane and other materials.
[0124] The plating device is designed such that the plating
solution is a conductive solution including copper or a conductive
solution in which other component is added to the conductive
solution including copper. Further, the plating solution includes
14 to 40 g of copper component as copper metal in 1 litter of the
plating solution. In the plating device, the anode is a soluble
anode plate made of high phosphorous copper.
Embodiment 2
[0125] With reference to FIGS. 9 to 12, the present embodiment will
detail the semiconductor wafer 1 used as a substrate to be plated
in Embodiment 1 and a method for manufacturing the substrate. They
are examples of a semiconductor device and a method for
manufacturing the semiconductor device. FIG. 9 is a drawing
schematically illustrating a structure of the semiconductor wafer 1
used in the present embodiment. FIG. 10 is a drawing schematically
illustrating a structure of a semiconductor chip 33 formed on the
semiconductor wafer 1 after a plating step. FIG. 10(a) is a plan
drawing. FIG. 10(b) is a cross sectional drawing.
[0126] As illustrated in FIG. 9, a plurality of semiconductor chips
41 are formed on a surface of the semiconductor wafer 1. A contact
section 42 is provided on the periphery of the semiconductor wafer
1. The contact section 42 includes a plating seed layer (not shown)
which is exposed. The contact section 42 touches the contact member
22 illustrated in FIG. 2.
[0127] As illustrated in FIG. 10(a), the semiconductor chip 41
includes a photoresist layer 18 which may have any shape. As
illustrated in FIG. 10(b), the semiconductor chip 41 after a
plating step has a seed layer 19 on its surface. The seed layer 19
has, on its surface, a wiring plating layer 16 and the photoresist
layer 18. A pad 17 is formed on the seed layer 19 so as to be
opposite to the wiring plating layer 16 and the photoresist layer
18. In the semiconductor chip 41, the wiring plating layer 16 and
the pad 17 are electrically connected with each other.
[0128] With reference to FIG. 11, the following explains procedures
of the method of the present embodiment for manufacturing a
semiconductor device. FIG. 11 is a cross sectional drawing which
illustrates the procedures.
[0129] As illustrated in FIG. 11, the method of the present
embodiment for manufacturing a semiconductor device includes: a
seed layer forming step of forming the seed layer 19 on the surface
of the semiconductor chip 41; a photoresist applying step of
applying the photoresist layer 18 on the seed layer 19; a
photoresist pattern forming step of forming any pattern on the
photoresist layer 18; a plating step of plating the photoresist
pattern with metal so that a wiring plating layer is formed; a
stripping step of stripping off the photoresist layer 18; and an
etching step of etching the seed layer 19. FIG. 11(a) is a drawing
schematically illustrating a partial structure of the semiconductor
chip 41 before the seed layer forming step. FIG. 11(b) is a drawing
schematically illustrating a partial structure of the semiconductor
chip 41 after the seed layer forming step. FIG. 11 (c) is a drawing
schematically illustrating a partial structure of the semiconductor
chip 41 after the photoresist applying step. FIG. 11(d) is a
drawing schematically illustrating a partial structure of the
semiconductor chip 41 after the photoresist pattern forming step.
FIG. 11(e) is a drawing schematically illustrating a partial
structure of the semiconductor chip 41 after the plating step. FIG.
11(f) is a drawing schematically illustrating a partial structure
of the semiconductor chip 41 after the stripping step. FIG. 11(g)
is a drawing schematically illustrating a partial structure of the
semiconductor chip 41 after the etching step.
[0130] As illustrated in FIG. 11(a), the semiconductor chip 41
before the seed layer forming step has the pad 17 formed thereon
via which an electric signal is exchanged with the outside.
[0131] As illustrated in FIG. 11(b), in the seed layer forming
step, the seed layer 19 is formed on the surface of the
semiconductor chip 41. Specifically, the semiconductor wafer 1
including the semiconductor chip 41 is positioned in a sputtering
device so that the seed layer is formed on the surface where the
pad is formed. Thereafter, 1000 .ANG. of a titan layer serving as
barrier metal is formed on the surface of the semiconductor wafer 1
and then 3000 .ANG. of a copper layer is formed on the surface.
[0132] The copper layer serves as the seed layer 19 for plating.
The seed layer 19 serves to promote growth of a plating member
(wiring plating layer 16) in the plating step which will be
mentioned later.
[0133] In the above example, the titan layer serving as barrier
metal is formed in the seed layer forming step. However, the layer
serving as barrier metal is not limited to this. The layer may be a
chrome layer or a layer made of an alloy of titan and tungsten.
Further, the layer may be any layer as long as it is made of metal
which assures a barrier effect.
[0134] Further, the thickness of the titan layer is not limited to
1000 .ANG.. The thickness may have any value of not less than 500
.ANG. as long as the titan layer assures a barrier effect. Further,
the thickness of the copper layer serving as the seed layer 19 for
plating is not limited to 3000 .ANG.. The thickness may have any
value of not less than 1000 .ANG. as long as the copper layer
assures even current density in the plating step.
[0135] As illustrated in FIG. 11(c), in the photoresist applying
step, the photoresist layer 18 is applied on the semiconductor
wafer 1 including the semiconductor chip 41 having the seed layer
19 thereon. In the photoresist applying step, photoresist (PMER
P-LA900; manufactured by TOKYO OHKA KOGYO CO., LTD.) is spin-coated
on the surface of the semiconductor wafer 1 by a spin coater for 30
seconds at 1500 rotations per minute, and then is heated at
115.degree. C. for 5 minutes.
[0136] In the above example, PMER P-LA900 is used as photoresist.
However, photoresist is not limited to this as long as it is
resistive to the plating step which will be mentioned later. An
example of photoresist is PMER N-CA3000 (manufactured by TOKYO OHKA
KOGYO CO., LTD.). Further, the method for applying photoresist is
not limited to spin-coating. For example, the photoresist layer 18
may be formed on the surface of the semiconductor wafer 1 by using
a dry film such as ORDYL MP100 Series (manufactured by TOKYO OHKA
KOGYO CO., LTD.).
[0137] In the photoresist applying step, photoresist is spin-coated
by a spin coater for 30 seconds at 1500 rotations per minute and
heated at 115.degree. C. for 5 minutes. However, the spin-coating
method is not limited to this.
[0138] For example, photoresist may be spin-coated at 1000 to 3000
rotations per minute so that photoresist has a sufficiently even
thickness, and then the photoresist is heated at 100 to 120.degree.
C. for 5 minutes or so.
[0139] As illustrated in FIG. 11(d), in the photoresist pattern
forming step, a pattern having any shape is formed on the
photoresist layer 18 formed in the photoresist applying step.
Specifically, after the photoresist applying step, the
semiconductor wafer 1 including the semiconductor chip 41 is set in
a photolithography machine (not shown). Then, g-ray (436 nm) is
irradiated to the photoresist layer 18. Thereafter, a developing
device (not shown) develops the photoresist layer 18 using
2.38%-TMAH aqueous solution, so that photoresist on a portion to be
subjected to wiring plating is removed.
[0140] In the above example, g-ray (436 nm) is irradiated to the
photoresist layer 18. However, the ray irradiated to the
photoresist layer 18 for exposure is not limited to this as long as
the ray allows photoresist to be exposed. Examples of the ray to be
irradiated to the photoresist layer 18 include i-ray (365 nm) and
deep ultraviolet ray (approximately 200 to 300 nm). Further, in the
photoresist pattern forming step, the photoresist layer 18 is
developed using 2.38%-TMAH aqueous solution. However, the
concentration of the TMAH aqueous solution is not limited to this.
For example, the concentration may be 1 to 3%. Alternatively,
25%-TMAH aqueous solution may be diluted with pure water so that
the solution has concentration appropriate for development.
[0141] As illustrated in FIG. 11(e), in the plating step, plating
is performed on a portion where the seed layer 19 is exposed as a
result of forming a pattern having any shape on the photoresist
layer 18 in the photoresist pattern forming step. Specifically,
after the photoresist pattern forming step, the semiconductor wafer
1 including the semiconductor chip 41 is positioned in a plating
device illustrated in FIG. 1. That is, the semiconductor wafer 1 is
positioned on the wafer holder 2 in the plating device. Then, the O
ring 21 and the contact member 22 are attached to the contact
member 42 of the semiconductor chip 41 by a wafer suppressor (not
shown). The plating step after the semiconductor wafer 1 has been
positioned in the plating device is the same as the plating method
explained in Embodiment 1 and therefore the explanation of the
plating step is omitted here.
[0142] In the stripping step, as illustrated in FIG. 11(f), the
photoresist layer 18 on the semiconductor chip 41 after the plating
step is stripped. Specifically, the semiconductor wafer 1 including
the semiconductor chip 41 in FIG. 11(e) is provided in a stripping
device (not shown). Then, the semiconductor wafer 1 is immersed in
a stripping solution (stripping solution 104; manufactured by TOKYO
OHKA KOGYO CO., LTD.) at 70.degree. C. for 20 minutes and shaken
occasionally. Consequently, the photoresist layer 18 formed on the
surface of the semiconductor wafer 1 is stripped.
[0143] In the above example, the semiconductor wafer 1 is immersed
in the stripping solution 104 at 70.degree. C. for 20 minutes and
shaken occasionally. However, the time for immersion is not limited
to this. For example, the time may be 15 to 25 minutes. Further,
the semiconductor wafer 1 may be immersed in R-100 (manufactured by
MITSUBISHI GAS CHEMICAL COMPANY, INC.) for example as a stripping
solution and shaken occasionally. Alternatively, acetone may be
used as a stripping solution.
[0144] In the etching step, as illustrated in FIG. 11(g), the seed
layer 19 which does not have the wiring plating layer 16 thereon is
removed by etching. Specifically, the semiconductor wafer 1
including the semiconductor chip 41 illustrated in FIG. 11(f) is
provided in an etching device (not shown). Then, the semiconductor
wafer 1 is immersed and shaken in 10%-ammonium persulfate aqueous
solution at 25.degree. C. for 1.5 minute, so as to etch the seed
layer 19 made of copper (Cu) other than the copper plating wiring
section (wiring plating layer 16) (so as to etch the seed layer 19
which does not have the wiring plating layer 16 thereon).
[0145] In the above example, in the etching step, the semiconductor
wafer 1 is immersed and shaken in 10%-ammonium persulfate aqueous
solution at 25.degree. C. for 1.5 minute. However, the aqueous
solution for etching is not limited to this. For example, the
aqueous solution may be 10%-sodium hydroxide aqueous solution,
40%-iron chloride aqueous solution, or other solution. The
temperature of the aqueous solution is not limited to this and may
be 15 to 40.degree. C.
[0146] Further, in the etching step, the semiconductor wafer 1 is
subsequently immersed and shaken in 25%-TMAH at 90.degree. C. for 1
hour. Consequently, the titan layer serving as barrier metal (not
shown) other than the copper plating wiring section (wiring plating
layer 16) (the titan layer which does not have the wiring plating
layer 16 thereon) is etched.
[0147] In the above example, the semiconductor wafer 1 is immersed
and shaken in 25%-TMAH at 90.degree. C. for 1 hour so that the
titan layer is etched. However, the aqueous solution for etching
the titan layer is not limited to this. For example, the aqueous
solution may be a mixture of: hydrochloric acid; and hydrofluoric
acid and nitric acid or other solutions.
[0148] As described above, the semiconductor wafer 1 including the
semiconductor chip 41 manufactured through the seed layer forming
step to the plating step is allowed by the plating step to be free
from deterioration in plating quality due to minute solid foreign
matters derived from a black film etc. Consequently, in the method
of the present embodiment for manufacturing a semiconductor device,
it is possible to prevent short between wires or other problems due
to minute solid foreign matters derived from a black film etc. As a
result, it is possible to form a more minute wiring pattern on the
surface of a semiconductor chip.
[0149] Further, the semiconductor chip 41 which has the wiring
plating layer 16 thereon and which is formed on the semiconductor
wafer 1 is provided with an external connection terminal. With
reference to FIG. 12, the following details an external connection
terminal providing step of providing the semiconductor chip 41
having the wiring plating layer 16 thereon with the external
connection terminal. FIG. 12 is a cross sectional drawing
illustrating the external connection terminal providing step.
[0150] The external connection terminal providing step includes: an
overcoat layer forming step of forming an overcoat layer on the
surface of the semiconductor chip 41 having the wiring plating
layer 16 thereon; an overcoat layer pattern forming step of forming
any pattern on the overcoat layer; and an external connection
terminal forming step of forming the external connection terminal
on the wiring plating layer 16 in line with the pattern of the
overcoat layer. FIG. 12(a) is a drawing schematically illustrating
a partial structure of the semiconductor chip 41 having the wiring
plating layer 16 thereon before the overcoat layer forming step.
FIG. 12(b) is a drawing schematically illustrating a partial
structure of the semiconductor chip 41 after the overcoat layer
forming step. FIG. 12(c) is a drawing schematically illustrating a
partial structure of the semiconductor chip 41 after the overcoat
layer pattern forming step. FIG. 12(d) is a drawing schematically
illustrating a partial structure of the semiconductor chip 41 after
the external connection terminal forming step.
[0151] As illustrated in FIG. 12(a), in the semiconductor chip 41
which has the wiring plating layer 16 thereon and which is formed
on the semiconductor wafer 1, the seed layer 19 is positioned below
the wiring plating layer 16 (the seed layer 19 is positioned at the
side where the pad 17 is positioned). The wiring plating layer 16
is electrically connected, via the seed layer 19, with the pad 17
formed on the semiconductor chip 41.
[0152] As illustrated in FIG. 12(b), in the overcoat layer applying
step, the overcoat layer 20 is formed on the semiconductor wafer 1
including the semiconductor chip 41 having the wiring plating 16
thereon. Specifically, the overcoat layer 20 (CRC-8000;
manufactured by SUMITOMO BAKELITE CO., LTD.) is spin-coated by a
spin coater for 30 seconds at 1500 rotations per minute and is
heated at 130.degree. C. for 5 minutes.
[0153] In the above example, in the overcoat layer applying step,
CRC-8000 series is used as the overcoat layer 20. However, the
material for the overcoat layer 20 is not limited to this. For
example, the material may be HD-8800 series (manufactured by
Hitachi Chemical). Further, the overcoat layer 20 may be a
photosensitive heat-resistive resin such as HD8000.
[0154] In the above overcoat layer applying step, the overcoat
layer is spin-coated by the spin coater for 30 seconds at 1500
rotations per minute and is heated at 130.degree. C. for 5 minutes.
However, the method for applying the overcoat layer is not limited
to this. For example, the semiconductor wafer is rotated at 1000 to
3000 rotations per minute so that the overcoat layer has
sufficiently even thickness and then the overcoat layer is heated
at 120 to 140.degree. C. for approximately 5 minutes.
[0155] As illustrated in FIG. 12(c), in the overcoat layer pattern
forming step, any pattern is formed on the overcoat layer 20.
Specifically, the semiconductor wafer 1 including the semiconductor
chip 41 is set in a photolithography machine (not shown) after the
overcoat layer applying step. The photolithography machine
irradiates g-ray (436 nm) to the overcoat layer 20. Thereafter, a
developing device (not shown) develops the overcoat layer 20 using
2.38%-TMAH aqueous solution, so that the overcoat layer 20
corresponding to a portion where an external connection terminal is
to be formed is removed. After the removal, the semiconductor wafer
1 is subjected to a hardening process in a nitrogen atmosphere at
300.degree. C. for 2 hours. With the overcoat layer pattern forming
step, the semiconductor chip 41 has the wiring plating layer 16
exposed at a portion where the external connection terminal is to
be formed.
[0156] In the above example, in the overcoat layer pattern forming
step, the photolithography machine irradiates g-ray (436 nm) to the
overcoat layer 20. However, the ray irradiated to the overcoat
layer 20 is not limited to this as long as the ray can expose the
overcoat layer. Examples of the ray irradiated to the overcoat
layer 20 include i-ray (365 nm) and deep ultraviolet ray
(approximately 200 to 300 nm).
[0157] In the overcoat layer pattern forming step, the overcoat
layer 20 is developed using 2.38%-TMAH aqueous solution. However,
the concentration of TMAH aqueous solution is not limited to this.
For example, the concentration may be 1 to 3%. Alternatively,
25%-TMAH aqueous solution may be diluted with pure water so as to
have a concentration appropriate for development.
[0158] In the overcoat layer pattern forming step, the overcoat
layer 20 corresponding to a portion where the external connection
terminal is to be formed is removed and then the semiconductor
wafer 1 is subjected to a hardening process in a nitrogen
atmosphere at 300.degree. C. for 2 hours. However, the step after
the removal of the overcoat layer is not limited to this. For
example, the step may be such that the semiconductor wafer 1 is
held at 250 to 350.degree. C. for 1.5 to 3 hours after the removal
of the overcoat layer. Further, a temperature-up process and a
temperature-down process may be provided before and after the step,
respectively.
[0159] As illustrated in FIG. 12(d), in the external connection
terminal forming step, an external connection terminal 26 is formed
at a portion where the overcoat layer 20 has been removed in the
overcoat layer pattern forming step. Specifically, the
semiconductor wafer 1 including the semiconductor chip 41 is
positioned in a solder ball mounter (not shown). Then, flux (not
shown) is applied on a portion where the wiring plating layer 16 is
exposed and where the external connection terminal is to be formed.
On the portion where the flux has been applied is mounted a solder
ball serving as the external connection terminal 26 which is held
by a tool (not shown). Thereafter, the semiconductor wafer 1
including the semiconductor chip 41 having the solder ball thereon
is provided in a reflow device at 245.degree. C. and the solder
ball is remelted and cooled down, so that the solder ball serving
as the external connection terminal 26 is attached to the wiring
plating layer 16.
[0160] In the above example, the solder ball serving as the
external connection terminal 26 is made of SnAg.sub.3.0Cu.sub.0.5
(M705; manufactured by Senju Metal Industry Co., Ltd.). However,
the solder ball is not limited to this. For example, the solder
ball may be made of Sn.sub.63Pb.sub.37. Alternatively, the solder
ball may be made of other lead-free solder.
[0161] In the external connection terminal forming step, heating
temperature of the reflow device is 245.degree. C. However, the
heating temperature is not limited to this. For example, the
heating temperature may be 240 to 250.degree. C.
[0162] The present invention is not limited to the above
embodiments, and a variety of modifications are possible within the
scope of the following claims, and embodiments obtained by
combining technical means respectively disclosed in the above
embodiments are also within the technical scope of the present
invention.
[0163] As described above, the plating device of the present
invention is designed such that the plating tank includes a
partition between the substrate-to-be-plated and the anode, the
partition separates the anode from the substrate-to-be-plated, and
the plating tank is divided into a substrate-to-be-plated chamber
and an anode chamber. Further, as described above, in the plating
method of the present invention, plating is performed while the
substrate-to-be-plated and the anode are separated from each other
by the partition and the plating tank is divided into the
substrate-to-be-plated chamber and the anode chamber. Consequently,
it is possible to prevent contamination of a plated surface due to
particles etc. made by the anode. As a result, it is possible to
prevent deterioration in plating quality due to minute solid
particles derived from a black film etc., without impairing
operativity.
[0164] Further, as described above, in the method of the present
invention for manufacturing a semiconductor device, in the plating
step, plating is performed while the anode and the
surface-to-be-plated are separated from each other in the plating
tank by the partition. Further, the semiconductor device of the
present invention is manufactured through the method. Consequently,
it is possible to obtain a semiconductor device which is free from
minute solid foreign matters derived from a black film etc. on the
surface of the anode and which has plated wiring with high
quality.
[0165] Further, it is preferable to arrange the plating device of
the present invention so as to further include a plating solution
jetting pipe for jetting the plating solution to the
surface-to-be-plated of the substrate-to-be-plated, the plating
solution jetting pipe being provided so as to penetrate the
partition and so as to allow the plating solution to flow into both
the substrate-to-be-plated chamber and the anode chamber.
[0166] With the arrangement, the plating solution jetting pipe is
provided so as to penetrate the partition and so as to allow the
plating solution to flow into both the substrate-to-be-plated
chamber and the anode chamber. Consequently, the plating solution
flowing into the plating tank can be divided into a laminar flow of
the plating solution to the plated substrate area and a laminar
flow of the plating solution to the anode chamber. As a result,
when the plating solution flows into the plating tank, it is
possible to jet the plating solution to the surface-to-be-plated of
the substrate-to-be-plated with sufficient flow speed and flow
rate.
[0167] An example of the structure allowing "the plating solution
to flow into both the substrate-to-be-plated chamber and the anode
chamber" is such that: the plating tank includes a first
cylindrical cup and a second cylindrical cup, the first cylindrical
cup is provided with the anode and has a bottom provided with a
plating solution flowing-in port via which the plating solution
flows into the plating tank, the second cylindrical cup has a
bottom which is the partition, and the plating solution jetting
pipe is provided so as to penetrate the partition and so as to
allow a laminar flow of the plating solution from the plating
solution flowing-in port to be divided into a laminar flow of the
plating solution to the first cylindrical cup and a laminar flow of
the plating solution to the second cylindrical cup.
[0168] It is preferable to arrange the plating device of the
present invention so that the plating solution flowing into the
anode chamber does not flow into the substrate-to-be-plated
chamber.
[0169] With the arrangement, the plating solution having flowed
into the plating tank is divided by the plating solution jetting
pipe into the plating solution to the substrate-to-be-plated
chamber and the plating solution to the anode chamber.
Electrification between the anode and the substrate-to-be-plated
makes the plating solution having flowed into the anode chamber
include particles derived from the anode. The plating solution
passes through the partition, thereby removing the particles.
Consequently, the particles do not reach the surface-to-be-plated.
As a result, it is possible to prevent the particles from
contaminating the plated surface.
[0170] Further, the plating device may be arranged so that the
plating tank further includes a plating solution flowing-out port
via which the plating solution having flowed into the anode chamber
flows out of the plating tank.
[0171] Further, it is preferable to arrange the plating device of
the present invention so that a portion which separates the anode
from the substrate-to-be-plated and which includes the partition in
the plating tank is partially or entirely made of a permeation
member which, when immersed in the plating solution, allows ions in
the plating solution to permeate the permeation member.
[0172] With the arrangement, when immersed in the plating solution,
the permeation member allows ions in the plating solution to
permeate the permeation member. Therefore, when a voltage is
applied over the plating solution, ions in the plating solution
permeate the permeation member. On the other hand, particles
derived from the anode do not permeate the permeation member.
Consequently, with the arrangement, it is possible to separate ions
from particles in the plating solution having flowed into the anode
chamber.
[0173] Further, the permeation member may be a semipermeable
membrane.
[0174] Further, the permeation member may include an ion exchange
membrane.
[0175] Further, it is preferable to arrange the plating device of
the present invention so that the partition has a thickness ranging
from 50 to 200 .mu.m.
[0176] Further, it is preferable to arrange the plating device of
the present invention so that the partition includes a hydrocarbon
cation exchange membrane.
[0177] Further, it is preferable to arrange the plating device of
the present invention so as to further include: a plating solution
supplying source for storing a plating solution to be supplied to
the plating tank; plating solution supplying means for supplying
the plating solution stored in the plating solution supplying
source to the plating tank; and plating solution filtering means
for filtering the plating solution supplied by the plating solution
supplying means, the plating solution stored in the plating
solution supplying source being supplied to the plating tank by the
plating solution supplying means and via the plating solution
filtering means, and the plating solution supplied to the plating
tank being supplied again to the plating solution supplying
source.
[0178] Further, the plating solution preferably includes a copper
component and is conductive.
[0179] There are various kinds of plating solutions for forming
various metals. With the arrangement, by using the plating solution
including a copper component, it is possible to form copper plating
on the surface-to-be-plated of the substrate-to-be-plated. "Copper
component" means copper metal, copper ions, or a composition
including copper ions.
[0180] Further, it is preferable that the plating solution includes
a copper component of not less than 14 g and not more than 40 g per
1 litter of the plating solution.
[0181] Further, it is preferable that the anode is a soluble anode
made of high phosphorous copper.
[0182] When an anode including pure copper is used, the amount of
foreign matters generated by the anode increases. On the other
hand, with the arrangement, the anode is a soluble anode made of
high phosphorous copper, and accordingly a black film is formed on
the surface of the anode. The black film traps copper complex ions
(Cu.sup.+) which are causes of foreign matters.
[0183] Further, the substrate-to-be-plated may be a semiconductor
wafer.
[0184] Further, it is preferable to arrange the method of the
present invention for manufacturing a semiconductor device so that
in the plating step, a flow of the plating solution is divided into
a flow to the surface-to-be-plated and a flow to a neighbor of the
anode.
[0185] As a result, when the plating solution flows into the
plating tank in the plating step, it is possible to jet the plating
solution to the surface-to-be-plated of the substrate-to-be-plated
with sufficient flow speed and flow rate.
[0186] Further, it is preferable to arrange the method of the
present invention so that in the plating step, the plating solution
having flowed to the neighbor of the anode does not flow to the
surface-to-be-plated.
[0187] With the arrangement, the plating solution including
particles generated by electrifying between the anode and the
substrate-to-be-plated does not reach the surface-to-be-plated of
the substrate-to-be-plated. Consequently, it is possible to prevent
the particles from contaminating the plated surface. Further, the
method may be arranged so that in the plating step, the plating
solution having flowed to a neighbor of the anode is caused to flow
out of the plating tank.
[0188] Further, it is preferable to arrange the method of the
present invention so that a portion which separates the anode from
the substrate-to-be-plated and which includes the partition in the
plating tank is partially or entirely made of a permeation member
which, when immersed in the plating solution, allows ions in the
plating solution to permeate the permeation member.
[0189] With the arrangement, when a voltage is applied over the
plating solution, ions in the plating solution permeate the
permeation member. On the other hand, particles derived from the
anode do not permeate the permeation member. Consequently, with the
arrangement, it is possible to separate ions from particles in the
plating solution having flowed into the anode chamber.
[0190] Further, the method of the present invention may be arranged
so that the permeation member is a semipermeable membrane.
[0191] Further, the method of the present invention may be arranged
so that the permeation member includes an ion exchange
membrane.
[0192] Further, it is preferable to arrange the method of the
present invention so that the partition has a thickness of not less
than 50 .mu.m and not more than 200 .mu.m.
[0193] Further, it is preferable to arrange the method of the
present invention so that the partition includes a hydrocarbon
cation exchange membrane.
[0194] Further, it is preferable to arrange the method of the
present invention so that the plating step includes the sub-steps
of: (i) supplying a plating solution stored in a plating solution
supplying source to the plating tank; (ii) filtering the plating
solution supplied in the sub-step (ii); and (iii) supplying again
the plating solution supplied to the plating tank to the plating
solution supplying source.
[0195] The sub-step (iii) is a sub-step in which: a plating
solution supplied from the plating solution supplying source in the
sub-step (i) is subjected to the sub-step (ii) and is supplied to
the plating tank and then is supplied again to the plating solution
supplying source. Specifically, the sub-step (iii) is a sub-step in
which: in the plating device of the present invention, a plating
solution stored in the plating solution supplying source is
supplied to the plating tank by the plating solution supplying
means and via the plating solution filtering means and the plating
solution supplied to the plating tank is supplied again to the
plating solution supplying source.
[0196] Further, it is preferable to arrange the method of the
present invention so that the plating solution includes a copper
component and is conductive.
[0197] It is preferable that the plating solution includes a copper
component of not less than 14 g and not more than 40 g per 1 litter
of the plating solution.
[0198] Further, it is preferable to arrange the method of the
present invention so that the anode is a soluble anode made of high
phosphorus copper.
[0199] Further, the method of the present invention may be arranged
so that the substrate-to-be-plated is a semiconductor wafer.
[0200] Further, it is preferable to arrange the method of the
present invention so as to further include the steps of: (II)
forming a seed layer on the surface-to-be-plated; (III) applying
photoresist on a surface of the seed layer formed in the step (II);
and (IV) forming a pattern by exposing and developing the
photoresist, the steps (II) to (IV) being performed before the
plating step.
[0201] In order to solve the foregoing problems, the semiconductor
device of the present invention is manufactured through the method
for manufacturing a semiconductor device.
[0202] With the arrangement, the semiconductor device is
manufactured through the method. Consequently, it is possible to
provide a semiconductor device which is free from minute solid
foreign matters derived from a black film etc. on the surface of
the anode and which has plated wiring with high quality.
[0203] The embodiments and concrete examples of implementation
discussed in the foregoing detailed explanation serve solely to
illustrate the technical details of the present invention, which
should not be narrowly interpreted within the limits of such
embodiments and concrete examples, but rather may be applied in
many variations within the spirit of the present invention,
provided such variations do not exceed the scope of the patent
claims set forth below.
INDUSTRIAL APPLICABILITY
[0204] As described above, the plating device of the present
invention is capable of preventing deterioration in plating quality
due to minute solid foreign matters derived from a black film etc.,
without impairing operativity. Therefore, the present invention is
applicable to the semiconductor industry.
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