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. 19, 1985
Filed:
Sep. 19, 1984
Applicant:
Inventors:
Minoru Taguchi, Oomiya, JP;
Gen Sasaki, Yokohama, JP;
Assignee:
Kabushiki Kaisha Toshiba, , JP;
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; B44C / ; C03C / ; C03C / ;
U.S. Cl.
CPC ...
156637 ; 29571 ; 29580 ; 148187 ; 156628 ; 156657 ; 1566591 ; 156662 ; 252 793 ; 252 794 ;
Abstract
A method for selectively etching a high impurity concentration semiconductor layer by making use of a difference in impurity concentration is disclosed. According to this method, the high impurity concentration semiconductor layer is exposed to an aqueous solution of a hydrogen fluoride-nitric acid-acetic acid-based etching solution while being subjected to ultrasonic-vibration.