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. 02, 1999
Filed:
Feb. 09, 1998
Seiichi Miyazaki, Nagano-ken, JP;
Sumiyoshi Okada, Nagano-ken, JP;
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Abstract
There is disclosed a method of cleaning a semiconductor wafer after lapping in the manufacture thereof comprising the steps of slicing a monocrystalline ingot into a semiconductor wafer, and chamfering, lapping, acid-etching, and then mirror-polishing the thus-obtained semiconductor wafer. The semiconductor wafer is cleaned in a strong-alkaline aqueous solution at a point of time after the lapping and before the acid-etching, such that the surface of the semiconductor wafer is dissolved in an amount in the range of 4-8 .mu.m. The cleaning method prevents generation of a protrusion on the outer circumferential end portion of the wafer in the subsequent acid-etching step.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile