Chemical mechanical planarization of metal substrates
AssigneeRodel Holdings, Inc.
InventorsGlenn C. Mandigo, Ross E. Barker, II, Craig D. Lack, Ian G. Sullivan, Wendy B. Goldberg
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Abstract
A method of polishing a wafer in a carrier by a polishing pad, controlling a ratio of platen speed to carrier speed (PS to CS) within a specific range, or controlling a first polishing step with a PS to CS ratio in the range of about 150:1 to about 1:150 followed by a second polishing step with a platen speed of about 0 to 20 rpm while maintaining the carrier speed used in the first polishing step, which maximizes clearing of residual material removed from a patterned wafer surface by polishing.
Claims8
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.
The method 1, wherein the fixed downforce is in a range of about 1 to 10 psi.
Dependencies are inferred from the claim text.