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. 24, 1992
Filed:
Dec. 02, 1991
Hiroyoshi Ando, Katsuta, JP;
Genya Matsuoka, Oume, JP;
Hiroyuki Takahashi, Yokohoma, JP;
Hidenori Yamaguchi, Kokubunji, JP;
Teruo Iwasaki, Hinode, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An electron beam lithography apparatus, comprising an electron beam source for irradiating an electron beam on a specimen surface, a deflectional controller of the electron beam, a focal controller of the electron beam on the specimen surface, a light source which irradiates two monochromatic lights on the surface having wavelengths which are different a half thereof each other, a signal processor for obtaining correction values in a height direction of the beam based on the reflected lights from the surface, and a means for adjusting the focal controller according to the correction values in the height direction. As the wavelengths of the two monochromatic lights on the surface are different in a half wavelength each other, an interference caused by a photo-resist on the specimen is prevented.