Short CMP polish method
AssigneeKoninklijke Philips Electronics N.V.
InventorsAndrew J. Black, Allison Deen
Life of this patent
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Abstract
A short CMP polish process is provided which removes minimal amounts of oxide and reduces defectivity at the surface of the wafer during short periods of rework by maintaining a high pH at the wafer surface in the presence of a high pH slurry. In one embodiment of the present inventions, the first platen of a multi-platen CMP machine is skipped for polishes of a short duration. In a second embodiment, a large amount of slurry is used to prime the second polish platen, thus displacing deionized water at the surface of the wafer which would ordinarily lower the initial pH of the process. Additionally, downforce may be minimized to reduce defectivity.
Claims20
A method of reworking a surface of a semiconductor wafer on a CMP machine, comprising:
- providing the wafer to the CMP machine;
- placing the surface of the wafer in contact with a polishing pad;
- ensuring a high pH on the surface of the wafer when placed on a the polishing pad;
- polishing the surface of the wafer on said polishing pad with a high pH slurry for less than 15 seconds,
- rinsing the polishing pad after said polishing step while the wafer surface is still in contact with said pad.
A method of reworking a semiconductor wafer on a multi-platen CMP machine, comprising:
- (a) providing the wafer to a first polishing pad of the multi-platen CMP machine;
- (b) polishing the wafer on said first polishing pad with a high pH slurry;
- (c) placing the wafer in contact with a second polishing pad;
- (d) ensuring a high pH on the surface of the wafer when placed on the second polishing pad;
- (e) polishing the surface of the wafer on said second polishing pad with a high pH slurry for less than 15 seconds,
- (f) rinsing the polishing pad after step (e) while the wafer surface is still in contact with said pad.
A system for reworking a semiconductor wafer on a multi-platen CMP machine, comprising:
- a multi-platen CMP machine including:
- a first polishing pad;
- a second polishing pad;
- a high pH slurry source for providing slurry to said first and second polishing pads,;
- a rinse source for providing a rinse solution to said first and second polishing pads;
- a control mechanism connected to said high pH slurry source and operable to provide slurry to said second polishing pad for at between 9 and 30 seconds to prime said second polishing pad;
- a control system for polishing the wafer on said second polishing pad for less than 15 seconds.
Dependencies are inferred from the claim text.