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:
Sep. 10, 1991
Filed:
Sep. 14, 1990
Hiroyuki Itoh, Kodaira, JP;
Kenichi Hirane, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Instrument Engineering Co., Ibaraki, JP;
Abstract
An electron beam lithography apparatus comprising an electron lens, a deflector, a reflective electron detector of marks on a stage or a specimen thereon when the deflector scans the marks, and a means for memorizing high order polynomial equations and calculating a correcting value of the deflector controlling means based on the high order polynomial equations, wherein all coefficients of the high order polynomial equation are calculated when the electron beam lithography apparatus starts up, and after then, coefficient of the first order term is calculated from the position signals of the marks frequently in a short cycle.