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:
Feb. 13, 2001
Filed:
Oct. 20, 1998
Applicant:
Inventors:
Assignee:
Fujitsu Limited, Kawasaki, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01R 3/126 ; H01L 2/166 ;
U.S. Cl.
CPC ...
G01R 3/126 ; H01L 2/166 ;
Abstract
A surface layer portion of a silicon substrate is etched by using a mixed solution which contains ammonium hydroxide (NH,OH), hydrogen peroxide (H,O,) and water (H,O) at a weight ratio of 1:(1.3 to 2.65):(275 to 433). The density of the etch pits which have occurred in a surface of the silicon substrate whose surface layer portion was etched by the etching step is measured. The crystal quality, etc. of the silicon substrate are evaluated before a process for manufacturing semiconductor devices using such silicon substrates, in order to avoid a lowering of the yields of the semiconductor devices.