The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 21, 2002
Filed:
Apr. 26, 2000
Sumit K. Guha, San Jose, CA (US);
Guangying Zhang, Chandler, AZ (US);
SpeedFam-IPEC Corporation, Chandler, AZ (US);
Abstract
A single-layer polishing pad is grooved in a pattern having relatively large turn radius bends (i.e., greater than the 90° bends of conventional rectangular grid grooving) to improve stability. The large radius bends allow slurry to be more easily and uniformly distributed across the surface of the polishing pad than conventional rectangular grooving. This improvement in slurry distribution tends to improve RR uniformity and WIWNU. In one embodiment, the polishing pad is grooved in a hexagonal pattern, which produces a grooving pattern with 120° bends. The grooves do not penetrate all of the way through the upper layer, thereby maintaining the “stiffness” of the polishing pad, which tends to improve planarization. When used in conjunction with standard pad conditioning techniques, polishing pads with groove patterns having large radius bends has yielded startling and unexpected improvement in stability. The improved fluid distribution provided by the groove pattern is believed to allow the pad conditioning process to clean the polishing pad of residual slurry, polishing debris and polishing by-products more thoroughly than polishing pads with conventional rectangular groove patterns.