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:
Nov. 15, 1994
Filed:
Mar. 23, 1992
Peter B Mumola, Huntington, CT (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
An apparatus for shielding a plurality of wafer registration surfaces 14, 30 and a wafer retention stage 26 from depreciative effects of a chemical etching process includes a pair of etching shields 32, 32' that are positioned along an outside edge of a wafer 10. The wafer 10 is registered to the wafer retention stage 26 by the registration surfaces 14, 30. The wafer retention stage 26, and hence the wafer 10, rotates about an axis 36 through the center of the wafer 10. A chemical etching instrument probe 18 is moved, with respect to the wafer 10, along a fixed wafer diameter 34 while the wafer 10 is rotating. The probe 18 is initially positioned above a first etching shield 32' and is moved, with respect to the wafer 10, across the wafer diameter 34 until it reaches a second etching shield 32. Thus, the probe 18 scans the entire surface of the wafer 10 without extending outside the wafer edge to depreciatively effect the wafer retention materials 14, 26, 30.