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:
Apr. 28, 1981
Filed:
Nov. 21, 1979
Yukichi Ueno, Katsuta, JP;
Teiji Katsuta, Mito, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method and an apparatus for testing a mask by an electron beam are disclosed in which the electron beam probe is first incident upon a predetermined point on a mask pattern of a photomask used to fabricate a semiconductor integrated circuit, the mask pattern is scanned by the electron beam probe from the predetermined point in a direction, the scanning operation is stopped when the electron beam probe reaches an edge of the mask pattern, the position of the edge or the distance between the predetermined point and the edge is determined by the number of pulse required to deflect the electron beam probe by a desired amount, and the position or distance thus determined is compared with the design data of the mask pattern to examine the dimensions of the mask pattern.