U.S. patents available from 1976 to present.
U.S. patent applications available from 2005 to present.

Process for treating polishing cloths used for semiconductor wafers

Patent 5167667 Issued on December 1, 1992. Estimated Expiration Date: Icon_subject June 5, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Patent References

3919101

Carbonated cleaning solution
Patent #: 4219333
Issued on: 08/26/1980
Inventor: Harris

System for continuously replenishing melt Patent #: 4968380
Issued on: 11/06/1990
Inventor: Freedman, et al.

Inventors

Application

No. 533479 filed on 06/05/1990

US Classes:

8/137, CLEANING OR LAUNDERING68/43, Squeezing and liquid flowing134/34, With treating fluid motion134/36Plural, separately fed, and either simultaneously applied or admixed, treating fluids

Examiners

Primary: Willis, Prince Jr.
Assistant: McNally, John F.

Attorney, Agent or Firm

International Class

D06B 005/00

Foreign Application Priority Data

1989-08-11 DE

Abstract

In the chemo-mechanical polishing, in particular, of semiconductor wafers, he abrasion and the geometrical quality of the wafers decreases with increasing service life of the polishing cloth. This can be prevented by treating the polishing cloth in each case after the polishing operation in a manner such that a pressure field is impressed, essentially without mechanical stress, on the polishing cloth, which pressure field causes a treatment liquid to flow through the interior of the polishing cloth and in this process the residues produced during polishing are rendered mobile and removed. A baseplate placed transversely across the polishing cloth and having a flat working surface provided with exit openings for the treatment liquid is suitable for carrying out the process. In the treatment, the treatment liquid is forced beneath the baseplate into the moving polishing cloth so that the latter is gradually traversed by the zone through which flow takes place.

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