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. 12, 1999
Filed:
Oct. 10, 1997
Kenichi Kawakami, Tokyo, JP;
Tatsuro Ohkawa, Tokyo, JP;
Kazushi Ishida, Tokyo, JP;
Akiyoshi Tsuda, Tokyo, JP;
Fujuitsu Limited, Kawasaki, JP;
Advantest Corporation, Tokyo, JP;
Abstract
The present invention is a charged particle beam exposure apparatus comprising: a column portion in which an optical system for a charged particle beam is disposed; a chamber to be coupled with the column portion; a movable sample stage located in the chamber for mounting a sample thereon; and a stage position measurement device, having an optical path for measurement, along which a laser beam having a predetermined frequency is projected and is reflected by reflection means provided on the sample stage, and an optical path for reference, which in length almost equals a distance between a starting point of the optical path for measurement and the origin of the optical system in the column portion and for which the length is increased at a rate substantially consistent with a thermal expansion coefficient as material of the chamber is expanded, for measuring a change in position of the sample stage by employing a laser optical signal for measurement, which passes along the optical path for measurement, and a reference laser signal, which passes along the optical path for reference.