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:
Sep. 12, 1995
Filed:
Jan. 05, 1994
Alan Strasbaugh, San Luis Obispo, CA (US);
Other;
Abstract
The apparatus is used to remove material uniformly from all regions of a wafer surface that is being polished. This is in contrast to conventional lapping machines which preferentially remove material from the high spots on the surface being polished so as to render the surface planar. The result of the present invention is achieved by providing a downwardly-opening plenum on the underside of a carrier. The opening is covered by a flexible membrane, and when a pressurized fluid is applied to the plenum, the membrane applies a uniform downward pressure across the entire upper surface of a wafer that is being polished. The uniform pressure results in a uniform removal of material all across the wafer. The wafer is typically 680 microns thick and the coating is typically two microns thick. Through use of the apparatus, the thickness of the coating is uniformly reduced to about 0.8 micron while maintaining the uniformity of the coating to within 0.02 micron.