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. 23, 2012
Filed:
Dec. 14, 2010
Zhongwei Chen, San Jose, CA (US);
Weiming Ren, San Jose, CA (US);
Kenichi Kanai, Palo Alto, CA (US);
Xuedong Liu, Cupertino, CA (US);
Zhongwei Chen, San Jose, CA (US);
Weiming Ren, San Jose, CA (US);
Kenichi Kanai, Palo Alto, CA (US);
Xuedong Liu, Cupertino, CA (US);
Hermes Microvision, Inc., Hsin-Chu, TW;
Abstract
An apparatus basically uses a simple and compact multi-axis magnetic lens to focus each of a plurality of charged particle beams on sample surface at the same time. In each sub-lens module of the multi-axis magnetic lens, two magnetic rings are respectively inserted into upper and lower holes with non-magnetic radial gap. Each gap size is small enough to keep a sufficient magnetic coupling and large enough to get a sufficient axial symmetry of magnetic scale potential distribution in the space near to its optical axis. This method eliminates the non-axisymmetric transverse field in each sub-lens and the round lens field difference among all sub-lenses at the same time; both exist inherently in a conventional multi-axis magnetic lens. In the apparatus, some additional magnetic shielding measures such as magnetic shielding tubes, plates and house are used to eliminate the non-axisymmetric transverse field on the charged particle path from each charged particle source to the entrance of each sub-lens and from the exit of each sub-lens to the sample surface.