Apparatus and method for electrically contacting wafer in electronic chemical plating cell

Abstract

An apparatus and method for electrically contacting a wafer in an electronic chemical plating cell includes a plating bath containing an electrolytic solution therein, an anode member arranged at a lower portion in the plating bath, a support member for arranging a wafer at an upper portion in the plating bath to face the anode member, a first cathode contact member electrically contacting an edge of the wafer, a second cathode contact member electrically contacting the center of the wafer, and a power supply electrically connected among the anode member, the first cathode contact member and the second cathode contact member to supply the power. Since resistance of a seed layer is reduced, it is possible to improve uniformity of the plating layer.

Description

This application claims the benefit of the Korean Patent Application No. P2005-85107, filed on Sept. 13, 2005, which is hereby incorporated by reference in its entirety.

BACKGROUND

1. Technical Field

The present invention relates to a semiconductor device, and more particularly, to an apparatus and method for electrically contacting a wafer in an electronic chemical plating cell.

2. Discussion of the Related Art

Generally, in a process of manufacturing a semiconductor device, an electronic chemical plating method using an electronic chemical plating cell is used as a method for forming a metal layer on a wafer.

FIG. 1 is a perspective view illustrating a related art electronic chemical plating cell.

Referring to FIG. 1, the related art electronic chemical plating cell includes a container 10. The container 10 is opened at the top to receive and support a wafer holder 12. Preferably, the container 10 is made of an annular cell of an electrical insulating material such as plastic, flexible glass (acryl product), LEXAN, PVC, CPVC, and PVDF.

The wafer holder 12 is used as a top cover of the container 10. The container 10 is generally formed to correspond to the shape and size of the wafer W. An inlet (not shown) is provided on the bottom of the container 10 so that an electron plating solution is supplied thereinto. The electron plating solution is supplied to the container 10 by a pump (not shown) connected with the inlet. Thus, the electron plating solution is in contact with a surface of the wafer W.

A cathode contact member 14 is arranged on a bottom surface of the wafer holder 12. For electron plating, the cathode contact member 14 supplies a current to the surface of the wafer W.

The cathode contact member 14, as shown in FIG. 2, includes a main body 14a, and contact strips 14b (or contact pins) extended from the main body 14a and contacting the wafer W. The cathode contact member 14 transfers electric energy supplied from an external power supply (not shown) to the wafer W. The contact pins 14b are in contact with the edge of the wafer W.

The container 10 further includes a chamber 18. The chamber 18 is provided with a consuming anode 16 for supplying a metal supply. Although not shown, the consuming anode 16 is made of a metal part covered with a porous cover, such as pure copper, a metal wire, a boring metal sheet or a solidified metal sheet. The consuming anode 16 is electrically connected with the power supply.

The contact pins 14b of the cathode contact member 14 are each formed with the same extension length L. Portions marked by black color at the ends of the contact pins 14b are in contact with the wafer W. The contact portion between the wafer W and the cathode contact member 14 is maintained in a region within the range of 2mm from the edge of the wafer W.

A related art apparatus and method for electrically contacting a wafer in an electronic chemical plating cell will now be described with reference to FIG. 3. For convenience of description, the container 10 and the chamber 18 shown in FIG. 1 are referred to as a plating bath 300 that is an external container of an electron chemical plating cell.

The related art apparatus for electrically contacting a wafer in an electronic chemical plating cell, as shown in FIG. 3, includes a plating bath 300 containing an electrolytic solution, a consuming anode 16 arranged at a lower portion in the plating bath 300, a wafer W arranged at an upper portion in the plating bath 300 to face the consuming anode 16, a cathode contact member 14 electrically contacting the edge of the plating surface of the wafer W along the corner of the wafer W, and a power supply 310 electrically connected between the consuming anode 16 and the cathode contact member 14 to supply the power. A metal seed layer (not shown) is formed on the plating surface of the wafer W.

Various factors affect the uniformity of the plating layer during an electronic chemical plating process. Examples of the factors include a resistance R_bath of the electrolytic solution, the distance D_plating between the wafer W and the consuming anode 16, a resistance R_seed of the metal seed layer, thickness of the metal seed layer, the uniformity of the seed layer, and the type of electric contact between the wafer W and the cathode contact member 14, which can be either a “wet” contact or a “dry” contact. “Wet” contact refers to the exposure of the contact portion between the wafer W and the cathode contact member 14 to the electrolytic solution as shown in FIG. 4. “Dry” contact refers to the sealing of the contact portion between the wafer W and the cathode contact member 14 using a bag member 41 so as not to expose the contact portion to the electrolytic solution, as shown in FIG. 5.

To obtain optimized uniformity required for the electronic chemical plating process with regard to the aforementioned factors, factors including high resistance R_bath of the electrolytic solution, the optimized distance D_plating, low resistance R_seed of the metal seed layer, thick seed layer and uniformity of the seed layer are required. Among the factors, the factors relating to the seed layer have been studied. However, many studies of the other factors are still required.

SUMMARY

Consistent with the present invention there is provided an apparatus and method for electrically contacting a wafer in an electronic chemical plating cell, which may substantially obviate one or more problems due to limitations and disadvantages of the related art.

Consistent with the present invention, there is provided an apparatus and method for electrically contacting a wafer in an electronic chemical plating cell, in which uniformity of a metal layer plated on a wafer may be optimized during an electronic chemical plating process.

Consistent with the invention, as embodied and broadly described herein, there is further provided an apparatus for electrically contacting a wafer in an electronic chemical plating cell includes a plating bath containing an electrolytic solution therein, an anode member arranged at a lower portion in the plating bath, a support member for arranging a wafer at an upper portion in the plating bath to face the- anode member, a first cathode contact member electrically contacting an edge of the wafer, a second cathode contact member electrically contacting the center of the wafer, and a power supply electrically connected to the anode member, the first cathode contact member and the second cathode contact member to supply the power.

The first cathode contact member is provided with a plurality of contact pins contacting the edge of the wafer several times along the corner of the wafer.

In another aspect consistent with the present invention, a method for electrically contacting a wafer in an electronic chemical plating cell includes preparing a plating bath containing an electrolytic solution, arranging an anode member at a lower portion in the plating bath, arranging a wafer at an upper portion in the plating bath to face the anode member, arranging a first cathode contact member to electrically contact an edge of the wafer, arranging a second cathode contact member to electrically contact the center of the wafer, and connecting a power source to the anode member, the first cathode contact member and the second cathode contact member to supply the power source.

The first cathode contact member contacts the edge of the wafer several times along the corner of the wafer, and the second cathode contact member contacts the center of the wafer one time or more.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation consistent with the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments consistent with the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 is a perspective view illustrating a related art electronic chemical plating cell;

FIG. 2 illustrates a cathode contact member of FIG. 1;

FIG. 3 illustrates an electrical contact structure of FIG. 1;

FIG. 4 illustrates a “wet” contact;

FIG. 5 illustrates a “dry” contact; and

FIG. 6 illustrates an apparatus and method for electrically contacting a wafer in an electronic chemical plating cell consistent with the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to the preferred embodiments consistent with the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

An apparatus and method for electrically contacting a wafer in an electronic chemical plating cell consistent with the present invention will be described with reference to FIG. 6.

FIG. 6 illustrates an apparatus and method for electrically contacting a wafer in an electronic chemical plating cell according to the present invention.

As shown in FIG. 6, the apparatus for electrically contacting a wafer in an electronic chemical plating cell includes a plating bath 600 having a container (not shown) and a chamber (not shown) to contain an electrolytic solution therein, an anode member 610 of copper arranged in the chamber provided at a lower portion in the plating bath 600, a wafer holder (not shown) serving as a support member for arranging a wafer W in the container provided at an upper portion in the plating bath 600 to face the anode member 610, a first cathode contact member 620 electrically contacting the edge of the wafer W, a second cathode contact member 630 electrically contacting the center of the wafer W, and a power supply 640 electrically connected to the anode member 610, the first cathode contact member 620 and the second cathode contact member 630 to supply the power.

Although not shown, the wafer holder may be comprised of the same structure as that of the wafer holder 12 shown in FIG. 1. The first cathode contact member 620 is provided with a plurality of contact pins, similar to contact pins 14b shown in FIG. 2, contacting the edge of the wafer W several times along the corner of the wafer W. The contact pins are formed at constant intervals. The first cathode contact member 620 has the same structure as that of the cathode contact member 14 shown in FIG. 2.

As described above with reference to FIG. 6, the method for electrically contacting a wafer in an electronic chemical plating cell consistent with the present invention is as follows.

The plating bath 600 containing the electrolytic solution is prepared. The anode member 610 is arranged at the lower portion in the plating bath 600. The wafer W is arranged at the upper portion in the plating bath 600 to face the anode member 610. The first cathode contact member 620 electrically contacts the edge of the wafer W, and the second cathode contact member 630 electrically contacts the center of the wafer W. The power is supplied to the anode member 610, the first cathode contact member 620 and the second cathode contact member 630.

The first cathode contact member 620 contacts the edge of the wafer W several times along the corner of the wafer W. The second cathode contact member 630 contacts the center of the wafer W one time or more.

As described above, in the apparatus and method for electrically contacting a wafer in an electronic chemical plating cell according to the present invention, since resistance R_seed of the seed layer is reduced, it is possible to improve uniformity of the plating layer. Also, in cases where a large-sized wafer having, for example, a thickness of 300 mm or greater, is used, it is possible to remarkably improve the uniformity of the plating layer.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

1. An apparatus for electrically contacting a wafer in an electronic chemical plating cell comprising:

a plating bath having an electrolytic solution therein;

an anode member arranged in a lower portion of the plating bath;

a support member for arranging a wafer in an upper portion of the plating bath to face the anode member;

a first cathode contact member electrically contacting an edge of the wafer;

a second cathode contact member electrically contacting the center of the wafer; and

a power supply electrically connected to the anode member, the first cathode contact member and the second cathode contact member.

2. The apparatus of claim 1, wherein the first cathode contact member is provided with a plurality of contact pins contacting the edge of the wafer along the corner of the wafer.

3. The apparatus of claim 2, wherein the contact pins are formed at constant intervals.

4. A method for electrically contacting a wafer in an electronic chemical plating cell comprising:

preparing a plating bath containing an electrolytic solution;

arranging an anode member in a lower portion of the plating bath;

arranging a wafer in an upper portion of the plating bath to face the anode member;

arranging a first cathode contact member to electrically contact an edge of the wafer;

arranging a second cathode contact member to electrically contact the center of the wafer; and

supplying electrical power from a power source connected to the anode member, the first cathode contact member and the second cathode contact member.

5. The method of claim 4, wherein arranging the first cathode contact member comprises arranging the first cathode contact member in contact with the edge of the wafer at a plurality of points along the corner of the wafer.

6. The method of claim 4, wherein arranging the second cathode contact member comprises arranging the second cathode contact member to contact the center of the wafer at a plurality of points.

7. The method as claimed in claim 4, wherein the wafer has a thickness of 300 mn or greater.