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. 22, 2005
Filed:
Jun. 18, 2002
Yoichiro Neo, Kokubunji, JP;
Mari Nozoe, Hino, JP;
Yoichiro Neo, Kokubunji, JP;
Mari Nozoe, Hino, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An inspection technique for enabling an inspection on a wafer at an early stage during a wafer process. A wafer in a process is irradiated with an electron beam a plurality of times at predetermined intervals under a condition that a junction is backward biased, and secondary electron signals are monitored, so as to evaluate relax time characteristic of a backward bias potential in a p-n junction. Since the potential in the p-n junction decreases according to the intensity of a backward bias current in intermittent time, a backward bias current can be specified from an intensity signal interrelated with the number of secondary electron signals, that is, a potential contrast image on the basis of image information.