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:
Jan. 28, 2003
Filed:
Nov. 13, 1998
Yasunari Sohda, Hachioji, JP;
Yasuhiro Someda, Kokubunji, JP;
Hiroya Ohta, Kodaira, JP;
Takashi Matsuzaka, Hitachinaka, JP;
Norio Saitou, Tokorozawa, JP;
Yoshinori Nakayama, Sayama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An electron beam lithography apparatus and a semiconductor device pattern forming method for precisely writing patterns near the periphery of a cell mask so that large scale integrated circuits and fine structure devices are fabricated at high yield rates. Cell figures with lower aperture rates are located peripherally and cell figures with higher aperture rates are located closer to a central portion within each of aperture groups furnished on a second mask of the inventive apparatus adopting cell projection. Illustratively, on a mask for use in semiconductor device fabrication, cell figures for forming line patterns and gate patterns are located centrally and cell figures for forming hole patterns are positioned peripherally in each aperture group. This allows the peripherally located figures to be written precisely in each aperture group.