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:
Jul. 07, 1992
Filed:
May. 02, 1991
Applicant:
Inventors:
Chang-Hwang Hua, Palo Alto, CA (US);
Ding Y Day, Sunnyvale, CA (US);
Assignee:
Avantek, Inc., Milpitas, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; B44C / ;
U.S. Cl.
CPC ...
156639 ; 156640 ; 156655 ; 156662 ; 156630 ; 156345 ; 252 795 ;
Abstract
A method for thinning a Gallium Arsenide (GaAs) layer on the backside of a wafer substrate is provided. The method involves spraying an etchant solution including NH.sub.4 OH and H.sub.2 O.sub.2, preferably in a 1:4 ratio, onto the GaAs layer as the wafer is rotated at approximately 2000 rpm. The etchant is sprayed through a plurality of spray nozzles. The process is capable of thinning a GaAs layer by about 500 .mu.m in approximately 14 to 18 minutes, depending on the etchant temperature and composition.