Electro-plating and apparatus for performing the same

Patent metadata

Field	Value
Publication number	US-9518334-B2
Application number	US-201313871712-A
Country	US
Kind code	B2
Filing date	Apr 26, 2013
Priority date	Mar 11, 2013
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

A method of plating a metal layer on a work piece includes exposing a surface of the work piece to a plating solution, and supplying a first voltage at a negative end of a power supply source to an edge portion of the work piece. A second voltage is supplied to an inner portion of the work piece, wherein the inner portion is closer to a center of the work piece than the edge portion. A positive end of the power supply source is connected to a metal plate, wherein the metal plate and the work piece are spaced apart from each other by, and are in contact with, the plating solution.

First claim

What is claimed is:

1. A method comprising:
plating a metal layer on a work piece, wherein the plating comprises:
exposing a surface of the work piece to a plating solution;
supplying a first voltage at a negative end of a first power supply source to an edge portion of the work piece;
contacting an electrical connection line of a retractable electrode with the work piece, wherein the retractable electrode comprises:
a cylinder comprising a seal ring and the electrical connection line encircled by the seal ring; and
an outer shell having a portion of the cylinder therein, wherein a length of the cylinder out of the outer shell is adjusted to contact the electrical connection line with the work piece;

supplying a second voltage to a first inner portion of the work piece through the electrical connection line, wherein the first inner portion is closer to a center of the work piece than the edge portion; and
connecting a positive end of the first power supply source to a metal plate, wherein the metal plate and the work piece are spaced apart from each other by, and are in contact with, the plating solution.

2. The method of claim 1 , wherein the first inner portion of the work piece is a center portion of the work piece.

3. The method of claim 1 , wherein the first inner portion of the work piece is comprised in a first chip of the work piece, wherein the first chip of the work piece has a surface profile different from surface profiles of a plurality of chips in the work piece, and wherein the first chip comprises a planar contact pad, with the first voltage applied on the planar contact pad through an electrical contact.

4. The method of claim 3 , wherein when the electrical contact is in physical contact with the planar contact pad, the planar contact pad is sealed by the seal ring, and wherein the seal ring is in contact with the planar contact pad.

5. The method of claim 1 , wherein the first voltage is substantially equal to the second voltage.

6. The method of claim 5 , wherein the second voltage is supplied by the first power supply source.

7. The method of claim 1 , wherein the first voltage is different from the second voltage, and wherein the second voltage is supplied by a second power supply source different from the first power supply source.

8. The method of claim 1 further comprising, when the plating is performed:
rotating the work piece; and
stirring the plating solution using a blade that is rotated together with the work piece.

9. A method comprising:
plating a metal layer on a wafer through electro-plating, wherein the electro-plating comprises:
exposing a surface of the wafer to a plating solution;
supplying a first voltage to an edge portion of the wafer, wherein the first voltage is connected through a plurality of electrical contacts that are in contact with the edge portion of the wafer, and wherein the plurality of electrical contacts is aligned to a ring adjacent to an edge of the wafer;
supplying a second voltage to a center portion of the wafer, wherein during the plating, the wafer acts as a cathode, and a metal plate acts as an anode, with a metal in the metal plate being plated to the wafer; and
stirring the plating solution using a blade that is rotated together with the wafer, wherein the blade comprises a vertical surface substantially perpendicular to a direction of rotation, and a major slant surface neither perpendicular to nor parallel to the vertical surface.

10. The method of claim 9 further comprising supplying the second voltage to the wafer through an electrical connection line embedded in the blade.

11. The method of claim 9 further comprising connecting a third voltage to a portion of the wafer, wherein the portion of the wafer is between the center portion of the wafer and the edge portion of the wafer.

12. The method of claim 9 , wherein the center portion of the wafer is comprised in a center chip of the wafer, wherein the center chip of the wafer has a surface profile different from surface profiles of a plurality of chips in the wafer, and wherein the center chip comprises a planar contact pad, with the first voltage applied on the planar contact pad.

13. The method of claim 9 , wherein the blade has a triangular shape in a cross-sectional view of the blade.

14. A method comprising:
contacting a plurality of edge portions of a front surface of a wafer to a plurality of electrical contacts;
contacting a center portion of the front surface of the wafer to an additional electrical contact by adjusting a length of a cylinder protruding out of an outer shell of a retractable electrode, wherein the additional electrical contact is a part of the cylinder; and
plating a metal layer on the front surface of the wafer, wherein during the plating, first voltages are applied on the plurality of electrical contacts and the additional electrical contact, and a second voltage higher than the first voltages is applied on a metal plate, wherein the metal plate and the wafer are spaced apart from each other by, and are in contact with, a plating solution.

15. The method of claim 14 , wherein the center portion has equal distances to the plurality of electrical contacts.

16. The method of claim 14 , wherein the plurality of electrical contacts and the additional electrical contact are supplied with different voltages.

17. The method of claim 14 comprising, when the plating is performed:
stirring the plating solution using a blade that is rotated together with the wafer, wherein the blade comprises a vertical surface substantially perpendicular to a direction of rotation, and a major slant surface neither perpendicular to nor parallel to the vertical surface.

18. The method of claim 14 , wherein the additional electric contact is a part of the retractable electrode, and the retractable electrode comprises a seal ring encircling the additional electrical contact, wherein the seal ring comprises a flexible material, and a surface of the additional electrical contact is co-planar with a surface of the seal ring.

19. The method of claim 18 , wherein the retractable electrode is fixed onto the wafer when the wafer is rotated.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Kao Chen-Yuan
• Su Hung-Wen
• Tsai Minghsing

Classifications

• C25D17/005 Primary

  Contacting devices · CPC title

• C25D17/004

  Sealing devices · CPC title

• C25D17/001

  Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells · CPC title

• C25D21/10

  Agitating of electrolytes; Moving of racks · CPC title

• C25D21/12 Primary

  Process control or regulation (controlling or regulating in general G05) · CPC title