Method for improving an electrodeposition process through use of a multi-electrode assembly

• US 6,706,166 B2
• Filed: 05/06/2002
• Issued: 03/16/2004
• Est. Priority Date: 05/06/2002
• Status: Expired due to Fees

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Tsai, Ming-Hsing, Chou, Shih-Wei
• Primary Examiner(s): Nicolas, Wesley A.
• Application Number:
  US10/139,975
• Publication Number:
  US 20030205477A1
• Time in Patent Office: 680 Days
• Field of Search: 205/87, 205/157, 205/123, 205/220, 205/221, 205/223, 205/291, 205/292, 205/640, 205/656, 205/659, 205/96
• US Class Current: 205/96
• CPC Class Codes: C25D 17/001 Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells
• CPC Class Codes: C25D 17/10 Electrodes , e.g. composition, counter electrode
• CPC Class Codes: C25D 5/18 Electroplating using modulated, pulsed or reversing current
• CPC Class Codes: C25D 7/12 Semiconductors
• CPC Class Codes: H01L 21/2885 using an external electrical current, i.e. electro-deposition
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material

Abstract

A method for improving an electrodeposited metal film uniformity and preventing metal deposition and peeling of deposited metal from an electrode during an electrodeposition and electropolishing process including providing a first anode electrode assembly and a semiconductor wafer plating surface disposed in an electrolyte bath including a plating metal for deposition onto the semiconductor wafer plating surface; providing at least one additional anode electrode assembly including the plating metal disposed peripheral to the first anode electrode assembly for selectively applying the cathodic electrical potential during an electropolishing process; and, periodically alternating between an electrodeposition process and electropolishing process with respect to the semiconductor wafer plating surface such that the plating metal is preferentially plated onto the at least one additional electrode assembly.

Claims

1. A method for improving a electrodeposited metal film uniformity and preventing metal deposition and peeling of deposited metal from an electrode during an electrodeposition and electropolishing process comprising the steps of:

providing a first anode electrode assembly and a semiconductor wafer plating surface disposed in an electrolyte bath comprising a plating metal for deposition onto the semiconductor wafer plating surface;

providing at least one additional anode electrode assembly comprising the plating metal disposed peripheral to the first anode electrode assembly for selectively applying the cathodic electrical potential during an electropolishing process; and

,

periodically alternating between an electrodeposition process and electropolishing process with respect to the semiconductor wafer plating surface such that the plating metal is preferentially plated onto the at least one additional electrode assembly.

2. The method of claim 1, wherein the first electrode assembly major surface is disposed facing and substantially parallel to the semiconductor wafer plating.

3. The method of claim 1, wherein the at least one additional anode electrode assembly is powered by a separate power supply.

4. The method of claim 1, wherein the first anode electrode assembly is deactivated during an electropolishing process.

5. The method of claim 1, wherein the electropolishing process is carried out for a sufficient period of time to at least partially clean semiconductor wafer electrode contacts contacting with the semiconductor wafer plating surface.

6. The method of claim 1, wherein electroplating of the plating metal onto the first electrode assembly is avoided.

7. The method of claim 1, wherein the first electrode assembly comprises a copper anode with an overlying titanium plate and the plating metal comprises copper.

8. The method of claim 7, wherein the copper anode comprises an additional material selected from the group consisting of Ta, nitrides of tantalum, gold, rhodium, titanium nitride, and titanium.

9. The method of claim 1, wherein the at least one additional anode electrode assembly consists essentially of the plating metal.

10. The method of claim 1, wherein the anode electrode assembly, the plating, and the at least one additional anode electrode assembly comprise copper.

11. The method of claim 1, wherein the at least one additional electrode assembly is positioned to surround the first electrode assembly.

12. The method of claim 1, wherein the at least one additional anode electrode assembly comprises two anode electrode assemblies arranged at the periphery to surround the first anode electrode assembly.

13. A method for improving an electroplating film uniformity by reducing metal plating accumulation and peeling of plated metal from an electrode assembly during an electrodeposition and electropolishing process comprising the steps of:

providing a first anode electrode assembly and a semiconductor wafer plating surface in contact with electrical contacts for applying a potential disposed in an electrolyte bath comprising a plating metal for deposition onto the semiconductor wafer plating surface;

providing at least one additional anode electrode assembly comprising the plating metal disposed peripheral to and surrounding the first anode electrode assembly for selectively applying a cathodic electrical potential during an electropolishing process; and

,

periodically alternating between an electrodeposition process and electropolishing process with respect to the semiconductor wafer plating surface wherein the plating metal is preferentially plated onto the at least one additional electrode assembly.

14. A method for improving a copper electroplating film uniformity by reducing copper plating accumulation and peeling of plated copper metal from an anodic electrode assembly during a copper electrodeposition and electropolishing process comprising the steps of:

providing a first anode electrode assembly comprising copper disposed in an electrolyte bath comprising copper for copper deposition onto a semiconductor wafer plating surface;

providing at least one additional anode electrode assembly comprising copper disposed to surround to the first anode electrode assembly for selectively applying a cathodic electrical potential during an electropolishing process; and

,

periodically reversing an electrolyte current flow to perform an electropolishing process with respect to the semiconductor wafer plating surface such that copper is preferentially plated onto the at least one additional electrode assembly.

15. The method of claim 14, wherein the first electrode assembly comprises a copper anode with an overlying metal plate.

16. The method of claim 15 wherein the overlying metal plate is selected from the group consisting of Ta, nitrides of tantalum, gold, rhodium, titanium nitride and titanium.