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. 29, 1988
Filed:
Mar. 02, 1988
Applicant:
Inventors:
Yoshihiko Saito, Yokosuka, JP;
Yoshiaki Matsushita, Kawasaki, JP;
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; B44C / ;
U.S. Cl.
CPC ...
252 794 ; 156657 ; 156662 ; 252 793 ;
Abstract
An etching solution used for evaluating crystal defects in a silicon wafer is disclosed. The etching solution is characterized by consisting of acetic acid, hydrofluoric acid, nitric acid, silver nitrate, and copper nitrate, and is very advantageous in consideration of the operator's health, since it does not contain Cr.sup.6+. The etching solution has a sufficiently high etching rate and detection properties.