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:
Sep. 20, 2005
Filed:
Oct. 15, 2003
Applicants:
Naohisa Sengoku, Kanagawa, JP;
Michikazu Matsumoto, Kyoto, JP;
Inventors:
Naohisa Sengoku, Kanagawa, JP;
Michikazu Matsumoto, Kyoto, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01R031/26 ;
U.S. Cl.
CPC ...
Abstract
A wafer for charge amount evaluation having a silicon substrate and p-type regions sandwiched between a first silicon oxide film and a SA-NSG film and surrounded by an undoped silicon film is prepared and subjected to a target process for which an amount of charge is to be evaluated. Then, etching is performed by using a BHF solution. By measuring an amount of etching in the p-type region, an amount of positive charge caused by the process in the wafer can be evaluated quantitatively in an easy and convenient manner.