U.S. patent application number 13/438020 was filed with the patent office on 2012-11-22 for apparatus and method for electroplating for semiconductor substrate.
Invention is credited to Ju-Il Choi, Dong Hyeon Jang, Ui Hyoung LEE, Jeong-Woo Park, Jae-Hyun Phee.
Application Number | 20120292195 13/438020 |
Document ID | / |
Family ID | 47174123 |
Filed Date | 2012-11-22 |
United States Patent
Application |
20120292195 |
Kind Code |
A1 |
LEE; Ui Hyoung ; et
al. |
November 22, 2012 |
APPARATUS AND METHOD FOR ELECTROPLATING FOR SEMICONDUCTOR
SUBSTRATE
Abstract
An apparatus for electroplating a semiconductor device includes
a plating bath accommodating a plating solution, and a paddle in
the plating bath, the paddle including a plurality of holes
configured to pass the plating solution through the paddle toward a
substrate, and a plating solution flow reinforcement portion
configured to selectively reinforce a flow of the plating solution
to a predetermined area of the substrate, the predetermined area of
the substrate being an area requiring a relatively increased supply
of metal ions of the plating solution.
Inventors: |
LEE; Ui Hyoung; (Seoul,
KR) ; Choi; Ju-Il; (Suwon-si, KR) ; Phee;
Jae-Hyun; (Incheon, KR) ; Jang; Dong Hyeon;
(Yongin-si, KR) ; Park; Jeong-Woo; (Suwon-si,
KR) |
Family ID: |
47174123 |
Appl. No.: |
13/438020 |
Filed: |
April 3, 2012 |
Current U.S.
Class: |
205/133 ;
204/275.1 |
Current CPC
Class: |
C25D 5/02 20130101; C25D
17/001 20130101; H01L 21/2885 20130101; C25D 17/008 20130101; C25D
5/08 20130101; C25D 7/123 20130101 |
Class at
Publication: |
205/133 ;
204/275.1 |
International
Class: |
C25B 15/00 20060101
C25B015/00; C25B 9/00 20060101 C25B009/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 19, 2011 |
KR |
10-2011-0047188 |
Claims
1. An apparatus for electroplating a semiconductor device, the
apparatus comprising: a plating bath accommodating a plating
solution; and a paddle in the plating bath, the paddle including: a
plurality of holes configured to pass the plating solution through
the paddle toward a substrate, and a plating solution flow
reinforcement portion configured to selectively reinforce a flow of
the plating solution to a predetermined area of the substrate, the
predetermined area of the substrate being an area requiring a
relatively increased supply of metal ions of the plating
solution.
2. The apparatus as claimed in claim 1, wherein the plating
solution flow reinforcement portion is on the paddle and faces the
substrate.
3. The apparatus as claimed in claim 2, wherein the plating
solution flow reinforcement portion includes at least one
protrusion member protruding from the paddle toward the
substrate.
4. The apparatus as claimed in claim 3, wherein the plating
solution flow reinforcement portion includes a plurality of the
protrusion members, the protrusion members being separated from
each other and arranged along a circumference of the paddle at a
same radius.
5. The apparatus as claimed in claim 3, wherein the at least one
protrusion member is detachable, the protrusion member being a tab
coupled to a corresponding hole of the plurality of holes in the
paddle.
6. The apparatus as claimed in claim 5, wherein the tab includes a
male thread, the tab being coupled to the corresponding hole via a
female thread on an inner surface of the hole.
7. The apparatus as claimed in claim 2, wherein the plating
solution flow reinforcement portion includes an insulation
material.
8. The apparatus as claimed in claim 2, wherein the plating
solution flow reinforcement portion includes at least one groove
recessed into a lower surface of the paddle.
9. The apparatus as claimed in claim 1, further comprising an anode
and a cathode in the plating bath, each of the anode and cathode
being separated from the paddle, and the plating solution flow
reinforcement portion being positioned in an electric field
generated between the anode and cathode.
10. The apparatus as claimed in claim 9, further comprising a
linear flow guide portion on the anode, the linear flow guide
portion being configured to linearly guide flow of the plating
solution toward the paddle.
11. The apparatus as claimed in claim 10, wherein the linear flow
guide portion is a turbulence suppressor pad coupled to a groove on
a surface of the anode, the turbulence suppressor pad having a
shape corresponding to the groove.
12. The apparatus as claimed in claim 10, wherein the linear flow
guide portion is a porous media coupled to the anode.
13. The apparatus as claimed in claim 1, further comprising a
plating solution ejection member at an upper portion of the plating
bath, the plating solution ejection member being configured to
eject the plating solution from the upper portion of the plating
bath toward a lower portion of the plating bath.
14. An apparatus for electroplating a semiconductor device, the
apparatus comprising: a plating bath accommodating a plating
solution; an anode and a cathode in the plating bath; a paddle
between the anode and cathode, the paddle being spaced apart from
each of the anode and cathode, and the paddle including: a
plurality of holes configured to pass the plating solution through
the paddle toward a substrate, the substrate being on the cathode,
and a plating solution flow reinforcement portion in an electric
field generated between the anode and cathode, the plating solution
reinforcement portion being positioned above a first area of the
substrate, the first area of the substrate receiving a lower amount
of the plating solution than a second area of the substrate when
the electric field is not generated.
15. The apparatus as claimed in claim 14, wherein the plating
solution flow reinforcement portion is in the paddle, a shape of
the plating solution flow reinforcement portion being configured to
increase eddy flow in the first area of the substrate.
16. A method of electroplating a semiconductor device, the method
comprising: determining a predetermined area of a substrate
requiring a relatively increased supply of metal ions of a plating
solution; providing a plating bath with a paddle, the paddle
including: a plurality of holes configured to pass the plating
solution through the paddle toward the substrate, and a plating
solution flow reinforcement portion configured to selectively
reinforce a flow of the plating solution in the predetermined area
of the substrate; installing the substrate in the plating bath; and
forming a plating film having a substantially uniform thickness on
an entire surface of the substrate by supplying the plating
solution to the plating bath and forming an electric field in the
plating bath.
17. The method as claimed in claim 16, wherein forming the electric
field in the plating bath includes forming the plating solution
flow reinforcement portion between an anode and a cathode in the
plating bath.
18. The method as claimed in claim 16, wherein providing the
plating bath includes forming the plating solution flow
reinforcement portion to include at least one protrusion member
that protrudes from the paddle toward the substrate.
19. The method as claimed in claim 18, wherein forming the plating
solution flow reinforcement portion includes arranging a plurality
of protrusion members along a circumference of the paddle at a same
radius and separated from each other, the protrusion members
including a plurality of tabs selectively coupled to the plurality
of holes of the paddle to be detachable.
20. The method as claimed in claim 16, wherein providing the
plating bath includes forming the plating solution flow
reinforcement portion to include at least one groove at a surface
of the paddle to be recessed from the surface.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent
Application No. 10-2011-0047188 filed on May 19, 2011, in the
Korean Intellectual Property Office, the disclosure of which is
incorporated herein in its entirety by reference.
BACKGROUND
[0002] 1. Field
[0003] The inventive concept relates to an apparatus and method for
electroplating a semiconductor substrate, and more particularly, to
an apparatus and method for electroplating a semiconductor
substrate with a uniform plate film on a surface thereof.
[0004] 2. Description of the Related Art
[0005] In general, electroplating apparatuses for plating a
material, e.g., silver and copper, on a surface of a part to be
plated, e.g., on a surface of a semiconductor wafer, use an
electroplating method. The electroplating method is widely used
because the property of a metal film coated by the electroplating
method is superior to that of a metal film coated by, e.g., a
chemical vapor deposition method or a physical vapor deposition
method.
[0006] According to the electroplating principle, a part to be
plated as a negative electrode and metal to be electrodeposited as
a positive electrode may be dipped into an electrolyte solution
containing metal ions to be electrodeposited. The two electrodes
are electrically connected to each other and electrolyzed so that
desired metal ions may be deposited on a surface of the part to be
plated.
SUMMARY
[0007] Embodiments are directed to an apparatus and method for
electroplating a semiconductor substrate by selectively increasing
the flow of an electrolyte solution at a predetermined area where a
supply amount of metal ions of the electrolyte solution needs to be
relatively increased, thereby increasing thickness uniformity of a
deposited metal layer formed by the electroplating.
[0008] According to an aspect of the inventive concept, there is
provided an apparatus for electroplating a semiconductor device
which includes a plating bath accommodating a plating solution, and
a paddle in the plating bath, the paddle including a plurality of
holes configured to pass the plating solution through the paddle
toward a substrate, and a plating solution flow reinforcement
portion configured to selectively reinforce a flow of the plating
solution to a predetermined area of the substrate, the
predetermined area of the substrate being an area requiring a
relatively increased supply of metal ions of the plating
solution.
[0009] The plating solution flow reinforcement portion may be on
the paddle and may face the substrate.
[0010] The plating solution flow reinforcement portion may include
at least one protrusion member protruding from the paddle toward
the substrate.
[0011] The plating solution flow reinforcement portion may include
a plurality of protrusion members, the protrusion members being
separated from each other and arranged along a circumference of the
paddle at a same radius.
[0012] The at least one protrusion member may be detachable, the
protrusion member being a tab coupled to a corresponding hole of
the plurality of holes in the paddle.
[0013] The tab may include a male thread, the tab being coupled to
the corresponding hole via a female thread on an inner surface of
the hole.
[0014] The plating solution flow reinforcement portion may include
an insulation material.
[0015] The plating solution flow reinforcement portion may include
at least one groove recessed into a lower surface of the
paddle.
[0016] The apparatus may further include an anode and a cathode in
the plating bath, each of the anode and cathode being separated
from the paddle, and the plating solution flow reinforcement
portion being position in an electric field generated between the
anode and cathode.
[0017] The apparatus may further include a linear flow guide
portion on the anode, the linear flow guide portion being
configured to linearly guide flow of the plating solution toward
the paddle.
[0018] The linear flow guide portion may be a turbulence suppressor
pad coupled to a groove on a surface of the anode, the turbulence
suppressor pad having a shape corresponding to the groove.
[0019] The linear flow guide portion may be a porous media coupled
to the anode.
[0020] The apparatus may further include a plating solution
ejection member at an upper portion of the plating bath, the
plating solution ejection member being configured to eject the
plating solution from the upper portion of the plating bath toward
a lower portion of the plating bath.
[0021] According to an aspect of the inventive concept, there may
also be provided an apparatus for electroplating a semiconductor
device which includes a plating bath accommodating a plating
solution, an anode and a cathode in the plating bath, a paddle
between the anode and cathode, the paddle being spaced apart from
each of the anode and cathode, and the paddle including a plurality
of holes configured to pass the plating solution through the paddle
toward a substrate, the substrate being on the cathode, and a
plating solution flow reinforcement portion in an electric field
generated between the anode and cathode, the plating solution
reinforcement portion being positioned above a first area of the
substrate, the first area of the substrate receiving a lower amount
of the plating solution than a second area of the substrate when
the electric field is not generated.
[0022] The plating solution flow reinforcement portion may be in
the paddle, a shape of the plating solution flow reinforcement
portion being configured to increase eddy flow in the first area of
the substrate.
[0023] According to an aspect of the inventive concept, there may
also be provided a method of electroplating a semiconductor device,
the method including determining a predetermined area of a
substrate requiring a relatively increased supply of metal ions of
a plating solution, providing a plating bath with a paddle, the
paddle including a plurality of holes configured to pass the
plating solution through the paddle toward the substrate, and a
plating solution flow reinforcement portion configured to
selectively reinforce a flow of the plating solution in the
predetermined area of the substrate, installing the substrate in
the plating bath, and forming a plating film having a substantially
uniform thickness on an entire surface of the substrate by
supplying the plating solution to the plating bath and forming an
electric field in the plating bath.
[0024] Forming the electric field in the plating bath may include
forming the plating solution flow reinforcement portion between an
anode and a cathode in the plating bath.
[0025] Providing the plating bath may include forming the plating
solution flow reinforcement portion to include at least one
protrusion member that protrudes from the paddle toward the
substrate.
[0026] Forming the plating solution flow reinforcement portion may
include arranging a plurality of protrusion members along a
circumference of the paddle at a same radius and separated from
each other, the protrusion members including a plurality of tabs
selectively coupled to the plurality of holes of the paddle to be
detachable.
[0027] Providing the plating bath may include forming the plating
solution flow reinforcement portion to include at least one groove
at a surface of the paddle to be recessed from the surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Features will become apparent to those of ordinary skill in
the art by describing in detail exemplary embodiments with
reference to the attached drawings, in which:
[0029] FIG. 1 schematically illustrates an apparatus for
electroplating a semiconductor substrate according to an exemplary
embodiment of the inventive concept;
[0030] FIG. 2 schematically illustrates a plan view of a paddle of
the electroplating apparatus of FIG. 1;
[0031] FIG. 3 illustrates a cross-sectional view taken along line
III-III of FIG. 2;
[0032] FIG. 4 illustrates an enlarged cross-sectional view of a
plated film formed on a substrate by an electrolyte solution flow
improvement portion on the paddle of FIG. 3;
[0033] FIG. 5 illustrates a flowchart of a method for
electroplating a semiconductor substrate according to an exemplary
embodiment of the present inventive concept;
[0034] FIG. 6 illustrates a cross-sectional view of a paddle of an
apparatus for electroplating a semiconductor substrate according to
another exemplary embodiment of the inventive concept;
[0035] FIG. 7 schematically illustrates an apparatus for
electroplating a semiconductor substrate according to another
exemplary embodiment of the inventive concept; and
[0036] FIG. 8 schematically illustrates major parts of an apparatus
for electroplating a semiconductor substrate according to another
exemplary embodiment of the inventive concept.
DETAILED DESCRIPTION
[0037] Example embodiments will now be described more fully
hereinafter with reference to the accompanying drawings; however,
they may be embodied in different forms and should not be construed
as limited to the embodiments set forth herein. Rather, these
embodiments are provided so that this disclosure will be thorough
and complete, and will fully convey the scope of the invention to
those skilled in the art.
[0038] In the drawing figures, the dimensions of layers and regions
may be exaggerated for clarity of illustration. It will also be
understood that when a layer (or element) is referred to as being
"on" another layer or substrate, it can be directly on the other
layer or substrate, or intervening layers may also be present. In
addition, it will also be understood that when a layer is referred
to as being "between" two layers, it can be the only layer between
the two layers, or one or more intervening layers may also be
present. Further, it will also be understood that when a layer is
referred to as being "connected to" another layer, it can be the
only layer connected to the other layer, or one or more intervening
layers may also be present. Other expressions describing the
relationship between the constituent elements may be construed in
the same manner. Like reference numerals refer to like elements
throughout.
[0039] Terms such as "first" and "second" are used herein merely to
describe a variety of constituent elements, but the constituent
elements are not limited by the terms. The terms are used only for
the purpose of distinguishing one constituent element from another
constituent element. For example, without departing from the right
scope of the present inventive concept, a first constituent element
may be referred to as a second constituent element, and vice
versa.
[0040] The terms used in the present specification are used for
explaining a specific exemplary embodiment, not limiting the
present inventive concept. Thus, the expression of singularity in
the present specification includes the expression of plurality
unless clearly specified otherwise in context. Also, the terms such
as "include" or "comprise" may be construed to denote a certain
characteristic, number, step, operation, constituent element, or a
combination thereof, but may not be construed to exclude the
existence of or a possibility of addition of one or more other
characteristics, numbers, steps, operations, constituent elements,
or combinations thereof.
[0041] Unless defined otherwise, all terms used herein including
technical or scientific terms have the same meanings as those
generally understood by those skilled in the art to which the
present inventive concept may pertain. The terms as those defined
in generally used dictionaries are construed to have meanings
matching that in the context of related technology and, unless
clearly defined otherwise, are not construed to be ideally or
excessively formal.
[0042] Hereinafter, the inventive concept will be described in
detail by explaining embodiments of the inventive concept with
reference to the attached drawings.
[0043] FIG. 1 schematically illustrates a structure of an apparatus
1 for electroplating a semiconductor substrate according to an
exemplary embodiment of the present inventive concept. FIG. 2
schematically illustrates a plan view of a paddle of the
electroplating apparatus of FIG. 1. FIG. 3 is a cross-sectional
view along line III-III of FIG. 2. FIG. 4 is an enlarged
cross-sectional view of a plated film formed on a substrate by the
apparatus 1 of FIG. 1.
[0044] Referring to FIGS. 1-4, the semiconductor substrate
electroplating apparatus 1 according to the present exemplary
embodiment may include a plating bath 10 containing a plating
solution, an anode 20 provided at an upper side of the inside of
the plating bath 10, a cathode 30 provided at a lower side of the
plating bath 10 separated from and facing the anode 20, and a
paddle 40 provided between the anode 20 and the cathode 30 to
control the flow of a plating solution. A substrate W to be plated
may be placed on the cathode 30, i.e., between the cathode 30 and
the paddle 40.
[0045] The plating bath 10 may be a vessel or a container for
accommodating a plating solution and for performing a plating work.
A plating solution ejection member 11, e.g., a nozzle 11, for
supplying a plating solution may be arranged at, e.g., a center
portion of an upper side of, the plating bath 10. The plating
solution ejection member 11 may be connected to a plating solution
storing tank T via a plating solution supply line L. A pump P and a
filter F may be sequentially provided along the plating solution
supply line L. Also, the plating solution storing tank T may be
connected to a plating solution return line RL.
[0046] In the present exemplary embodiment, the plating solution
ejection member 11 may be arranged at the upper side of the plating
bath 10 and may supply a plating solution from the upper side of
the plating bath 10 to the lower side thereof, so that the plating
solution forms a downward flow. However, the scope of the present
inventive concept is not limited thereto. That is, by having a
surface of the substrate W exposed in the downward direction, e.g.,
by exposing a bottom surface of the substrate, which is opposite to
the arrangement according to the present exemplary embodiment, the
cathode 30 may support the substrate W at the upper side and the
plating solution ejection member 11 may supply the plating solution
from the lower side to the upper side.
[0047] Also, in the present exemplary embodiment, the plating
solution ejection member 11, i.e., the nozzle 11, penetrates
through the anode 20 so that the supply or downward flow of the
plating solution is not interrupted by the anode 20. Although only
one plating solution ejection member 11 is provided in the present
exemplary embodiment, the scope of the present inventive concept is
not limited thereto and a plurality of plating solution ejection
members may be provided. The plating solution supplied from the
plating solution ejection member 11 may be ejected in one direction
or may be sprayed in a plurality of directions. The plating
solution accommodated in the plating bath 10 may include, e.g.,
silver ions, nickel ions, copper ions, gold ions, or a combination
thereof.
[0048] The anode 20 is connected to a positive terminal of a power
supply unit 50 and functions as a positive electrode. In the
present exemplary embodiment, the anode 20 is arranged at the upper
side of the plating bath 10. Any material that does not contaminate
a plating solution during a plating work may be used as a material
for the anode 20. For example, either an insoluble material or a
soluble material may be used for the anode 20.
[0049] In the case of using an insoluble material, an anode
reaction voltage increases, so decomposition reaction of an organic
additive increases. Also, the plating solution may be contaminated
by byproducts after the decomposition reaction. Thus, the reaction
voltage is controlled or the insoluble material may be used with an
apparatus for controlling the decomposition reaction not to affect
the plating solution.
[0050] In the case of using a soluble material for the anode 20,
since an anode component is dissolved in the plating solution, the
plating solution may be contaminated. To prevent such a problem,
the same material as a plating material included in the plating
solution may be used. Also, when the anode component is dissolved
in the plating solution, a surface of the anode 20 becomes uneven
so that the distance from each point on the surface of the anode 20
to the substrate W that is a part to be plated may vary.
Accordingly, a difference in charge density may occur at the
respective positions in an adjacent area of the substrate W that is
a part to be plated due to the difference in the distance. Thus,
when the anode 20 formed of a soluble material is in use, the
difference in charge density due to the difference in the distance
may be reduced by separating the anode 20 from the cathode 30 by a
predetermined distance.
[0051] The cathode 30 may be provided at the lower side of the
plating bath 10 and may form an electric field in the plating bath
10 with the anode 20. The substrate W that is a part to be plated
may be installed at one side of the cathode 30 facing the anode 20.
The substrate W may be supported by the cathode 30.
[0052] The cathode 30 may be installed to be electrically connected
to the substrate W that is a part to be plated. For example, when
the cathode 30 is installed in a form of a jig connected to an
external power, a peripheral portion of the substrate W that is a
part to be plated is placed across the jig so that the substrate W
and the cathode 30 may be electrically connected to each other. The
substrate W may be, e.g., a wafer.
[0053] The paddle 40 may be provided in the plating bath 10 to be
disposed between the anode 20 and the cathode 30. By controlling
the flow of a plating solution, the paddle 40 may selectively
adjust an amount of plating ions deposited on the surface of the
substrate W, so that a plating film with a substantially uniform
thickness may be deposited on an entire surface of the substrate
W.
[0054] The paddle 40 may include an area for passing plating ions
and an area for blocking the plating ions. For example, as
illustrated in FIG. 2, the paddle 40 may have a circular plane
shape, and a plurality of holes 40a, i.e., paths through which the
plating ions pass, may be formed in the paddle 40.
[0055] The distance from the paddle 40 to the anode 20 or the
cathode 30 may be properly adjusted in accordance with factors of
the electroplating process, e.g., supply speed of a plating
solution, movement speed of plating ions, composition of an
additive used, etc.
[0056] The paddle 40 may be formed of an insulation material or a
surface thereof may be coated with an insulation material. Examples
of an insulation material may include ceramic,
polytetrafluorethylene, polyvinyl chloride, polypropylene,
polycarbonate, polyethylene, polystyrene, etc.
[0057] In general, among factors for determining a plating
thickness, it is important how rapidly metal ions of a plating
solution are supplied. For example, an amount of supplied metal
ions may be relatively increased by making the flow of metal ions
smooth, thereby increasing a plating thickness.
[0058] In the present exemplary embodiment, however, in order to
increase thickness uniformity, a predetermined area of the
substrate W, where a plating thickness is relatively thin, e.g.,
due to low supply of metal ions during plating, may be recognized.
Further, an increased supply of metal ions, e.g., only, to the
predetermined area may increase uniformity of plating thickness and
composition as compared to a related art. To this end, in the
present exemplary embodiment, a plating solution flow reinforcement
portion 41 may be provided in the paddle 40 to achieve uniform
thickness of a deposited film. That is, the plating solution flow
reinforcement portion 41 may selectively reinforce the flow of a
plating solution at the predetermined area of the substrate W,
i.e., where the amount of supplied metal ions is low. Thus, the
thickness of a plating film may be uniform compared to a related
art.
[0059] As illustrated in FIG. 1, the plating solution flow
reinforcement portion 41 may be a protrusion extending from the
paddle 40 toward the substrate W. For example, a plurality of
protrusions may protrude downwardly from the paddle 40.
[0060] Also, in the present exemplary embodiment, the plating
solution flow reinforcement portion 41, i.e., the protrusion
members 41, may be arranged along a circumference of the paddle 40,
i.e., at a same radius. The protrusion members 41 may be separated
from each other and coupled to the holes 40a of the paddle 40. When
the protrusion members 41 are coupled to the paddle 40 to protrude
downwardly, the plating solution passing through the holes 40a of
the paddle 40 generates eddy flow in the vicinity under each of the
protrusion members 41. Accordingly, the supply of metal ions under
each of the protrusion members 41 increases.
[0061] In detail, when the predetermined area of the substrate W,
i.e., where the plating thickness is relatively thin because the
amount of supply of metal ion is relatively small during the
plating process, is recognized, the metal ions are rapidly supplied
to the predetermined area through the plating solution flow
reinforcement portion 41. That is, the protrusion members 41 are
arranged and provided on the paddle 40 to protrude downwardly,
i.e., from the paddle 40 toward the cathode 30, at regions
corresponding to the predetermined area. As a result, a plating
film M may have increased thickness in regions under the protrusion
members 41, as illustrated in FIG. 4. For example, determining the
predetermined area, positioning the protrusions in the desired
area, and controlling the eddy flow may be conducted by a pre-test
or a simulation. Therefore, an overall thickness of the plating
film may be uniform.
[0062] The protrusion members 41 may be formed by attaching tabs
41' into some of the holes 40a of the paddle 40. For example, the
protrusion members 41 may be detachable, so the tabs 41' may be
selectively inserted into respective holes 40a to overlap the
predetermined region of the substrate W. When the tabs 41' are used
as the protrusion members 41, as illustrated in FIG. 3, a male
thread is formed on the tab 41' and a female thread is formed on an
inner surface of each of the holes 40a, so that the tabs 41' may be
screw coupled to each of the holes 40a. A screw coupling method of
the tabs 41' may be replaced with other coupling methods, e.g.,
interference fit coupling. Also, although in the present exemplary
embodiment the tab 41' has a circular cross-sectional shape, the
scope of the present inventive concept is not limited thereto,
e.g., the tab 41' may have a variety of shapes according to the
thickness and composition of the plating film.
[0063] For example, the protrusion members 41 may be formed of an
insulation material, e.g., the same insulation material as the
paddle 40, not to prevent the flow of current in the plating bath
10. In another example, surfaces of the protrusion members 41 may
be coated with an insulation material.
[0064] As such, the plating solution flow reinforcement portion 41,
i.e., the protrusion members 41, installed at the paddle 40
according to example embodiments may increase the thickness of the
plating film in a vertical area under the protrusion members 41 and
the composition of the plating ions, i.e., silver ions.
Accordingly, when the protrusion members 41 are properly installed
above an area of the substrate W to be plated, the thickness or
composition of the plating film may be selectively controlled. As a
result, the thickness or composition of the plating film may be
made substantially uniform on an entire surface of the substrate
W.
[0065] A method of electroplating a semiconductor substrate using
the apparatus for electroplating a semiconductor substrate
according to the above-described exemplary embodiment is described
below with reference to FIG. 5. FIG. 5 is a flowchart of a method
for electroplating a semiconductor substrate according to an
exemplary embodiment of the present inventive concept.
[0066] As described above, the method of electroplating a
semiconductor substrate according to the present exemplary
embodiment may include determining a predetermined area of the
substrate W that requires an increased supply of plating solution
to form a plating film with a substantially uniform thickness on
the entire surface of the substrate W (S100), providing the plating
bath 10 with the paddle 40 and the plating solution flow
reinforcement portion 41 for selectively reinforcing flow of the
plating solution in the predetermined area (S200), installing the
substrate W in the plating bath 10 (S300), and forming a plating
film on the surface of the substrate W by supplying the plating
solution to the plating bath 10 and forming an electric field
between the anode 20 and the cathode 30 provided in the plating
bath 10 (S400).
[0067] In detail, the predetermined area of the substrate W to be
plated may be determined (S100). The predetermined area may be a
first area of the substrate W, which conventionally receives, i.e.,
without use of the plating solution flow reinforcement portion 41,
a lower amount of metal ions of the plating solution during plating
than a second area of the substrate W.
[0068] Then, the paddle 40 having the plating solution flow
reinforcement portion 41 for selectively reinforcing flow of the
plating solution in the predetermined area is provided in the
plating bath 10 (S200). That is, the plating solution flow
reinforcement portion 41, i.e., the protrusion members 41, may be
installed in holes 40a of the paddle 40 that correspond to the
predetermined area in the substrate W.
[0069] The substrate W that is a part to be plated is installed in
the plating bath (S300), such that the predetermined area of the
substrate W corresponds to the protrusion members 41. That is, the
substrate W may be positioned on the cathode 30, so that centers of
the protrusion members 41 overlap, e.g., are aligned with, centers
of corresponding predetermined areas in the substrate W that
require increased metal ion flow.
[0070] Next, in S400, a plating solution may be supplied using the
plating solution ejection member 11, so that the plating solution
contacts the substrate W in the plating bath 10. The power supply
unit 50 electrically connected to the anode 20 and the cathode 30
applies a voltage, thereby forming an electric field along a
direction from the anode 20 to the cathode 30.
[0071] The plating solution proceeds toward the substrate W
according to the electric field and passes through the holes 40a of
the paddle 40. Thus, metal ions adsorb to the surface of the
substrate W that is electrically connected to the cathode 30,
thereby forming a plating film on the surface of the substrate W
(S400). While the plating solution passes through the holes 40a of
the paddle 40, eddy flow is generated in the vicinity under each of
the protrusion members 41 due to the electric field. Accordingly,
flow of metal ions from the plating solution under the protrusion
member 41 may be increased, thereby increasing deposition thickness
of the film in regions under the protrusion members 41, i.e., rapid
supply of the metal ions provides a relatively thick plating
thickness in the vicinity under each of the protrusion members 41.
Thus, the thickness of the plating film may be made uniform.
[0072] The plating solution supplied by the plating solution
ejection member 11 to the plating bath 10 may be returned through
the plating solution return line RL and resupplied to the plating
bath 10 after a cleansing process (not shown).
[0073] FIG. 6 is a cross-sectional view schematically illustrating
a paddle of an apparatus for electroplating a semiconductor
substrate according to another exemplary embodiment. The following
description discusses only portions different from the
above-described exemplary embodiment.
[0074] Referring to FIG. 6, a plating solution flow reinforcement
portion 43 may be provided in a form of a groove recessed into a
lower surface 40b of the paddle 40, i.e., a groove 43. For example,
portions of the lower surface 40b of the paddle 40 may be slightly
concave, e.g., a predetermined region between two adjacent holes
40a may include a cavity extending from the lower surface 40b of
the paddle 40 toward the anode 20. The groove 43 may have a, e.g.,
gentle, semi-oval shape or may be formed integrally with the paddle
40. However, the scope of the present inventive concept is not
limited thereto, e.g., the groove 43 may be formed on the paddle 40
through post-processing after the paddle 40 is formed.
[0075] When the groove 43 is provided as described above, eddy flow
is generated in the vicinity under the groove 43. Thus, supply of
metal ions of the plating solution may be relatively increased
under the groove 43, so that the plating film may have a relatively
thick plating thickness in the vicinity under the groove 43. Thus,
the thickness of the plating film may be made uniform by
recognizing a predetermined area of a substrate where the plating
thickness is relatively thin during a plating process and
increasing plating solution flow through the plating solution flow
reinforcement portion 43. In other words, the groove 43 in the
paddle 40 according to the present exemplary embodiment may rapidly
supply metal ions to the predetermined area of the substrate W.
[0076] FIG. 7 schematically illustrates a structure of an apparatus
for electroplating a semiconductor substrate according to another
exemplary embodiment of the present inventive concept. FIG. 8
schematically illustrates the structure of major parts of an
apparatus for electroplating a semiconductor substrate according to
another exemplary embodiment of the present inventive concept.
[0077] Referring to FIGS. 7 and 8, a plating bath 10' may include
in the present exemplary embodiment the plating solution ejection
member 11, i.e., the nozzle 11, above an anode 20a, so the nozzle
11 may not pass through the anode 20a. The plating bath 10' may
further include a linear flow guiding portion 21a (23a in FIG. 8)
on an upper surface of the anode 20a for guiding the plating
solution supplied by the plating solution ejection member 11 to
uniformly flow toward the paddle 40 along the upper surface of the
anode 20a.
[0078] For example, as illustrated in FIG. 7, the linear flow
guiding portion 21a may be a turbulence suppressor pad (TSP) 21a.
The TSP 21a may have a shape corresponding to a groove formed in
the upper surface of the anode 20a, and may be used to prevent
whirling of the plating solution when supplied by the plating
solution ejection member 11. The TSP 21 a may guide a linear flow
of the plating solution supplied by the plating solution ejection
member 11 to fill the TSP 21a, and then to flow over the upper
surface of the anode 20a.
[0079] In another example, as illustrated in FIG. 8, the linear
flow guiding portion 21a may be a porous media 23a installed on the
upper surface the anode 20a to protrude toward plating solution
ejection member 11. The porous media 23a may prevent scattering of
the plating solution when supplied by the plating solution ejection
member 11. The porous media 23a may guide a linear flow of the
plating solution supplied by the plating solution ejection member
11 to pass through the holes formed in the porous media 23a and be
discharged from the holes, thereby preventing scattering or
whirling of the plating solution.
[0080] Thus, the linear flow of the plating solution toward the
paddle 40 may be controlled, e.g., guided, to flow linearly. When
the linear flow of the plating solution is guided toward the paddle
40, scattering of the plating solution contacting the substrate W
is prevented. Therefore, unwanted whirling may be restricted,
thereby providing substantially uniform plating.
[0081] As described above, according to the apparatus and method
for electroplating a semiconductor substrate according to the
present inventive concept, plating may be made uniform overall by
selectively increasing the flow of an electrolyte solution at a
predetermined area, i.e., an area where a supply amount of metal
ions of the electrolyte solution needs to be relatively increased.
As such, uniform film thickness and composition in an overall
surface of the substrate to be plated may be maintained. Thus,
plating quality of a semiconductor substrate, e.g., a semiconductor
wafer, in an electroplating process may be improved.
[0082] In contrast, a conventional method of controlling
electroplated film thickness may include dividing an anode facing a
substrate into a plurality of anodes having insulation areas, i.e.,
a central anode and peripheral anodes. In this state, a plating
thickness may be controlled by making the plating time of the
central anode shorter than that of the peripheral anodes. In
another conventional method, the cathode and anode may be divided
into a plurality of cathodes and anodes, so that a current mirror
circuit may be formed to control and perform uniform
electrodeposition over an overall surface of the substrate, i.e.,
via the plurality of electrodes. However, dividing the electrodes
into a plurality of parts in the conventional apparatus and method
may make the structure of the electroplating apparatus complicated,
and may require adjustment of the apparatus for different substrate
diameters, i.e., the shape and division of the electrodes may be
changed in accordance with the size of the substrate. Further, a
separate control of the divided anodes may require a plurality of
rectifiers, thereby increasing costs.
[0083] In another conventional method, the uniformity of a plating
film may be improved by controlling the flow of an electrolyte
solution, i.e., by controlling the flow pressure of an electrolyte
solution using a nozzle or controlling the rotation speeds of a
wafer and a paddle. However, there is a limit in improving the
uniformity of plating with only the control of the flow of an
electrolyte solution using a nozzle or the rotation speeds of a
wafer and a paddle.
[0084] Example embodiments have been disclosed herein, and although
specific terms are employed, they are used and are to be
interpreted in a generic and descriptive sense only and not for
purpose of limitation. In some instances, as would be apparent to
one of ordinary skill in the art as of the filing of the present
application, features, characteristics, and/or elements described
in connection with a particular embodiment may be used singly or in
combination with features, characteristics, and/or elements
described in connection with other embodiments unless otherwise
specifically indicated. Accordingly, it will be understood by those
of skill in the art that various changes in form and details may be
made without departing from the spirit and scope of the present
invention as set forth in the following claims.
* * * * *