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:
May. 30, 1995
Filed:
Nov. 22, 1993
Applicant:
Inventor:
Toshiaki Kitano, Itami, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09K / ; H01L / ;
U.S. Cl.
CPC ...
1566561 ; 252 791 ;
Abstract
An etchant includes an organic acid and hydrogen peroxide mixed in a volume ratio of 1:1 to 200:1 with a basic material added to adjust the pH. The etching solution presents an eminent difference in the etching rates between GaAs/AlGaAs, GaAs/InGaAs, AlGaAs/InGaAs, InGaAs/AlGaAs, and InGaAs/GaAs. High selectivity etching is completed easily and with high precision. Precise control of etching of a heterostructure is achieved.