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. 22, 1980
Filed:
Nov. 21, 1978
Susumu Ozasa, Kashiwa, JP;
Hitachi, Ltd., , JP;
Abstract
An apparatus for electron beam lithography for automatically focusing a shaped electron beam uniformly projects an electron beam onto a reference aperture plate having an opening of a prescribed shape. The electron beam in the shape of the opening of the aperture thus obtained is reduced or concentrated and then projected onto a specimen, to thereby project the specimen as a microscopic pattern. The apparatus periodically changes the direction of the electron beam disposed between an electron gun emitting the electron beam and the reference aperture plate, and detects the deviation of the position of the final-image electron beam corresponding to the angle of deflection of the electron beam. The focal distance of a final-stage electron lens is adjusted so as to minimize positional deviation and thereby focus the projected electron beam.