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:
Jun. 16, 2009
Filed:
Jun. 09, 2006
Masaki Hasegawa, Sayama, JP;
Hiroshi Makino, Kokubunji, JP;
Hikaru Koyama, Kodaira, JP;
Zhaohui Cheng, Tokyo, JP;
Hisaya Murakoshi, Tokyo, JP;
Masaki Hasegawa, Sayama, JP;
Hiroshi Makino, Kokubunji, JP;
Hikaru Koyama, Kodaira, JP;
Zhaohui Cheng, Tokyo, JP;
Hisaya Murakoshi, Tokyo, JP;
Hitachi High-Technologies Corporation, Tokyo, JP;
Abstract
In the present invention, the structure of an electrification control electrode is changed from a grid type to a slit type and thereby shadows are not formed when a wafer is irradiated with a beam. Further, a beam forming slit is disposed ahead of an electrification control slit, thus the electrification control slit is prevented from being irradiated with an electron beam for preliminary electrification, and thereby secondary electrons which disturb the control of the electrification are inhibited from being generated. The shape of the slit is designed so that the strength of an electron beam may gradually decrease toward both the ends of an electron beam irradiation region in the longitudinal direction thereof. Furthermore, a preliminary static eliminator to remove or reduce the unevenness in an electrification potential distribution which has undesirably been formed earlier is disposed.