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:
Dec. 26, 1989
Filed:
Mar. 30, 1989
Masahiro Noguchi, Ushiku, JP;
Osamu Yamamoto, Ushiku, JP;
Abstract
The present invention polishes the surface of a substrate or epitaxial layer of Al.sub.x Ga.sub.1-x As wherein 0<x<1.0 with a polishing liquid comprising an aqueous alkali hypochlorite solution or a mixture of said aqueous solution with an alkali carbonate, said liquid being regulated to a pH value ranging from 8.0 to 11.0, and further containing a powder such as SiO.sub.2 or a colloidal material such as colloidal silica having a fine particle size to afford a planar mirror-surface to said surface, thereby preventing wafer cracking or pattern flowing during patterning by photomasks and improving yields.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile