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:
Feb. 28, 1989
Filed:
Jun. 17, 1987
Masahide Okumura, Sagamihara, JP;
Takashi Matsuzaka, Kokubunji, JP;
Genya Matsuoka, Ome, JP;
Kazumi Iwadate, Isehara, JP;
Tadahito Matsuda, Atsugi, JP;
Ryoichi Yamaguchi, Zami, JP;
Hitachi Ltd., Tokyo, JP;
Nippon Telegraph and Telephone Corp., Tokyo, JP;
Abstract
A mark position detection system used in a charged particle beam apparatus and including detection circuit for detecting a reflected electron generated at a mark when the mark is scanned with a charged particle beam, to obtain a mark signal, and signal processing circuit for comparing the mark signal from the detection circuit with a predetermined threshold level to find the position of the charged particle beam at a time the mark signal traverses the threshold level, thereby detecting the position of a mark edge, is disclosed in which, when the mark signal traverses the threshold level and has a peak value exceeding a predetermined value, it is determined by the signal processing circuit that the position of the charged particle beam at a time point at which the mark signal traverses the threshold level is the position of the mark.