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:
Jun. 07, 2011
Filed:
Apr. 02, 2009
Hiroyasu Kaga, Mito, JP;
Hiroyasu Kaga, Mito, JP;
Hitachi High-Technologies Corporation, Tokyo, JP;
Abstract
An object of the present invention is to provide a focused ion beam apparatus that is capable of obtaining a much larger beam current and forming a focused ion beam with smaller aberration than a conventional focused ion beam apparatus no matter whether the level of acceleration is high or low. The focused ion beam apparatus according to the present invention includes a liquid metal ion source, an extraction electrode for extracting an ion beam from the liquid metal ion source, an acceleration (ground) electrode for accelerating an ion beam, and an electrostatic lens for converging an ion beam. When the acceleration voltage applied to the liquid metal ion source is lower than an emission threshold voltage of the liquid metal ion source, the voltage of the extraction electrode is at a lower potential than the voltage of the acceleration (ground) electrode. The polarity of a voltage applied to the electrostatic lens changes in accordance with the polarity of a voltage applied to the extraction electrode. The present invention makes it possible to exercise a deceleration mode focusing method at a high acceleration voltage from the dielectric strength voltage of an electrostatic lens and exercise an acceleration mode focusing method at a low acceleration voltage with an electrostatic lens having the same focal length as for the deceleration mode focusing method.