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. 08, 2014
Filed:
Nov. 01, 2012
Keigo Kasuya, Kokubunji, JP;
Takashi Ohshima, Saitama, JP;
Souichi Katagiri, Kodaira, JP;
Shigeru Kokubo, Mito, JP;
Hideo Todokoro, Hinode, JP;
Keigo Kasuya, Kokubunji, JP;
Takashi Ohshima, Saitama, JP;
Souichi Katagiri, Kodaira, JP;
Shigeru Kokubo, Mito, JP;
Hideo Todokoro, Hinode, JP;
Hitachi High-Technologies Corporation, Tokyo, JP;
Abstract
A charged particle beam apparatus includes a field emission electron source, electrodes for applying an electric field to the field emission electron source, and a vacuum exhaust unit for keeping the pressure around the field emission electron source at 1×10Pa or less. The apparatus uses electron beams emitted to have an electron-beam-center radiation angle of 1×10sr or less, and uses the electric current thereof, the second order differentiation of which is negative or zero with respect to time, and which reduces at a rate of 10% or less per hour. A heating unit is provided for the field emission electron source, and a detection unit is provided for the electric current of the electron beam. The field emission electron source is repeatedly heated to keep the electric current of the electron beam to be emitted, at a predetermined value or higher.