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. 05, 1991
Filed:
Aug. 03, 1988
Applicant:
Inventors:
Satoru Fushimi, Yokohama, JP;
Hiroya Koshishiba, Yokohama, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
250310 ; 250311 ; 250397 ;
Abstract
An auto-focusing electron microscope used for the observation, measurement and/or checking of a circuit pattern or the like comprises an objective lens capable of changing a focal position of an electron beam, an optical system for projecting a light and shade pattern having a light-permeable portion and a light-shielding portion onto the surface of a specimen through the objective lens, and a detector for detecting the projected pattern while optically reflecting it, whereby focusing can be made while reducing any damage and/or charging of the specimen.