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:
Nov. 09, 1999
Filed:
Oct. 02, 1996
Yoshihisa Ooaeh, Kawasaki, JP;
Akio Yamada, Kawasaki, JP;
Hiroshi Yasuda, Kawasaki, JP;
Hitoshi Tanaka, Tokyo, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A charged particle beam exposure method and apparatus, in which a charged particle beam is shaped based on pattern data and the shaped charged particle beam is irradiated to a desired location on a sample. The method and apparatus includes introducing ozone gas into a chamber through which the charged particle beam is passed, shaped and deflected, to be irradiated to the desired location while the charged particle beam is irradiated through the chamber. The ozone gas concentration in the chamber is maintained so that the concentration downstream along the beam is higher than the concentration upstream along the beam. A charge-up drift due to a contamination material from a resist on a wafer can be avoided by the ozone self cleaning. The ozone oxidation does not occur at the upstream chamber where there is a lower ozone concentration and lower contamination.