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:
Nov. 06, 1990
Filed:
Apr. 18, 1989
Applicant:
Inventors:
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
2504922 ; 250398 ;
Abstract
A scanning electron beam exposure system includes two apertures (39a, 48a) for forming a rectangular beam (31). The cross section of the rectangular beam is changed by a deflection unit (47X, 47Y) arranged between the two apertures. The rectangular beam is refocused by a refocusing coil (51) to improve the peripheral sharpness of a projected image of the beam. The refocusing coil is controlled in accordance with the cross section (X.sub.1, Y.sub.1) of the beam.