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:
Oct. 19, 1999
Filed:
Aug. 26, 1997
Akio Takemoto, Kawasaki, JP;
Yoshihisa Ooaeh, Kawasaki, JP;
Tomohiko Abe, Kawasaki, JP;
Hiroshi Yasuda, Kawasaki, JP;
Takamasa Satoh, Kawasaki, JP;
Hideki Nasuno, Kasugai, JP;
Hidefumi Yabara, Kawasaki, JP;
Kenichi Kawakami, Kawasaki, JP;
Kiichi Sakamoto, Kawasaki, JP;
Tomohiro Sakazaki, Kasugai, JP;
Isamu Seto, Kawasaki, JP;
Masami Takigawa, Kawasaki, JP;
Tatsuro Ohkawa, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A method of exposing a wafer to a charged-particle beam by directing to the wafer the charged-particle beam deflected by a deflector includes the steps of arranging a plurality of first marks at different heights, focusing the charged-particle beam on each of the first marks by using a focus coil provided above the deflector, obtaining a focus distance for each of the first marks, obtaining deflection-efficiency-correction coefficients for each of the first marks, and using linear functions of the focus distance for approximating the deflection-efficiency-correction coefficients to obtain the deflection-efficiency-correction coefficients for an arbitrary value of the focus distance. A device for carrying out the method is also set forth.