Claims
- 1. A method for chemical-mechanical planarization of a metal layer on a semiconductor wafer, comprising:i. affixing the wafer in a rotatable carrier of a polishing machine, and rotating the carrier at a rotational carrier speed, CS; ii. affixing a polishing pad to a rotatable platen of the polishing machine, and rotating the platen at a rotational platen speed, PS, wherein the ratio of PS to CS is in a range of 2:1 to 10:1 and iii. contacting the wafer and the polishing pad with a fixed down force while maintaining relative motion therebetween, while dispensing a polishing fluid at an interface of the wafer and the polishing pad, the polishing fluid containing less than 0.01 weight percent abrasives, to provide a planarized surface of the wafer.
- 2. The method of claim 1 wherein the ratio of PS to CS has the range of 2:1 to 6:1.
- 3. The method 1, wherein the fixed downforce is in a range of about 1 to 10 psi.
- 4. The method of claim 1 wherein the fixed downforce is in a rang of about 1 to 5 psi.
- 5. The method of claim 1 wherein the polishing pad is an abrasive-free pad.
- 6. The method of claim 1 wherein the polishing fluid has a pH under 5 and further includes:i. polyacrylic acid having a number average molecular weight of about 20,000 to 150,000; ii. 1 to 15% by weight, based on the weight of the polishing fluid, of an oxidizing agent; iii. 50 to 5000 parts per million by weight of an inhibitor; and iv. up to 3% by weight, based on the weight of the polishing fluid, of a complexing agent.
- 7. The method of claim 6 wherein the polishing fluid has a pH of about 2.8 to 4.2 and the polyacrylic acid has a number average molecular weight of about 25,000 to 75,000 and is present in an amount of about 0.05 to 1.0% by weight, based on the weight of the polishing fluid.
- 8. The method of claim 6 wherein the metal is copper.
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Provisional Application Ser. No. 60/224,339 filed Aug. 11, 2000 and Provisional Application Ser. No. 60/227,466 filed Aug. 24, 2000.
US Referenced Citations (14)
Foreign Referenced Citations (6)
Number |
Date |
Country |
0 373 501 |
Jun 1990 |
EP |
0 888 846 |
Jan 1999 |
EP |
0 913 442 |
May 1999 |
EP |
9625270 |
Aug 1996 |
WO |
WO 99 64527 |
Dec 1999 |
WO |
WO 00 37217 |
Jun 2000 |
WO |
Provisional Applications (2)
|
Number |
Date |
Country |
|
60/224339 |
Aug 2000 |
US |
|
60/227466 |
Aug 2000 |
US |