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:
Jul. 31, 2012
Filed:
Aug. 04, 2009
Soichi Katagiri, Kodaira, JP;
Takashi Ohshima, Higashimurayama, JP;
Soichi Katagiri, Kodaira, JP;
Takashi Ohshima, Higashimurayama, JP;
Hitachi I High-Technologies Corporation, Tokyo, JP;
Abstract
To provide a small electron gun capable of keeping a high vacuum pressure used for an electron microscope and an electron-beam drawing apparatus. An electron gun constituted by a nonevaporative getter pump, a heater, a filament, and an electron-source positioning mechanism is provided with an opening for rough exhausting and its automatically opening/closing valve, and means for ionizing and decomposing an inert gas or a compound gas for the nonevaporative getter pump. It is possible to keep a high vacuum pressure of 10Torr without requiring an ion pump by using a small electron gun having a height and a width of approximately 15 cm while emitting electrons from the electron gun.