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:
May. 16, 1995
Filed:
Dec. 30, 1993
Kazuo Okubo, Kawasaki, JP;
Akio Ito, Kawasaki, JP;
Takayuki Anbe, Kawasaki, JP;
Hironori Teguri, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A method of measuring a voltage with an electron beam apparatus considers a change in a convergence factor due to a change in an S curve, as well as an error in a secondary electron signal level with a phase of measurement being scanned at random, to accurately measure the voltage. The method measures the voltage of a voltage measuring spot on a sample, prepares an analytic voltage by superimposing a probe voltage having an average of 0 V and no correlation with the measured voltage on the measured voltage, measures a secondary electron signal level with the analytic voltage, computes a convergence factor around a slice level set on the S curve according to a correlation between the secondary electron signal level and the probe voltage and according to an autocorrelation of the probe voltage, and updates the analytic voltage according to the convergence factor, thereby updating the measured voltage.