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. 20, 1999
Filed:
Nov. 20, 1996
Godfrey Augustine, Monroeville, PA (US);
Donovan L Barrett, Pittsburgh, PA (US);
Elizabeth Ann Halgas, Monroeville, PA (US);
Northrop Grumman Corporation, Los Angeles, CA (US);
Abstract
Silicon carbide wafers are prepared for semiconductor epitaxial growth by first lapping a silicon carbide wafer derived from a boule, by placing the wafer in a recess of a metal backed template and moving the wafer over and against a rotating plate. Two different diamond slurry mixtures of progressively smaller diamond grit sizes are sequentially used, along with a lubricant, for a predetermined period of time. The lapping operation is followed by a polishing operation which sequentially utilizes two different diamond slurry mixtures of progressively smaller diamond grit sizes, along with three different apertured pads sequentially applied to a rotatable plate, with the pads being of progressively softer composition. In a preferred embodiment the wafers are cleaned and the templates are changed after each new diamond slurry mixture used.