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:
Oct. 10, 1978
Filed:
Nov. 17, 1977
Kazumitsu Tanaka, Tokyo, JP;
Nobuo Goto, Tokyo, JP;
Nihon Denshi Kabushiki Kaisha, Tokyo, JP;
Abstract
A reference mark, common to both an electron beam and a workpiece, is arranged above and away from, but in the vicinity of, the workpiece exposure area. The position of the workpiece with respect to the reference mark is ascertained by an optical measuring means such as a Michelson type laser interferometer and the position of the electron beam with respect to the reference mark is ascertained by scanning the electron beam over said reference mark. The relative positions of the electron beam and the exposed workpiece is obtained by comparing the respective positions of the electron beam and workpiece with the reference mark. By so doing, the error between specified and actual positions of the points of impingement of the electron beam on the surface of the workpiece may be corrected.