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:
Apr. 24, 1990
Filed:
May. 16, 1986
Walter Torbert, Newark, CA (US);
Kenneth C Struven, San Carlos, CA (US);
Robert E Lorenzini, Atherton, CA (US);
Anthony C Bonora, Menlo Park, CA (US);
Siltec Corporation, Menlo Park, CA (US);
Abstract
A polishing apparatus has a conventional carrier with a plurality of floating subcarriers. The benefits of single wafer polishing are achieved with the economies of multiple wafer polishing by adding the plurality of floating subcarriers to the conventional carrier. Each subcarrier has a single wafer adhered to its underside. Axial freedom is provided to duplicate the dynamics of single wafer polishing. The required axial freedom is obtained by axially loading each subcarrier via a mechanical spring or via pneumatic/hydraulic devices. In two variations, each subcarrier is also allowed auto-rotational freedom. In another two variations, the subcarriers are rotationally driven. In all variations, the wafers adhered to the floating subcarriers are substantially uniformly polished and the total indicated reading of the maximum deviation on the wafer surface is improved.