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. 06, 2007
Filed:
Apr. 11, 2003
Applicants:
Etsuko Asano, Atsugi, JP;
Masahiko Hayakawa, Atsugi, JP;
Yoshiko Ikeda, Atsugi, JP;
Inventors:
Assignee:
Semiconductor Energy Laboratory Co., Ltd., Kanagawa-ken, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01R 27/28 (2006.01);
U.S. Cl.
CPC ...
Abstract
The invention performs an AC stress test assuming the CMOS operation and an AC stress test using a ring oscillator (R.O.) between a DC stress test method using single semiconductor elements and an aging test method. The deterioration of a semiconductor apparatus can be estimated highly precisely by separately performing the AC stress test assuming the CMOS operation on OFF-stress and ON-stress.