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. 17, 2006
Filed:
Apr. 27, 2004
N. William Parker, Fairfield, CA (US);
N. William Parker, Fairfield, CA (US);
Multibeam Systems, Inc., Santa Clara, CA (US);
Abstract
A charged particle beam column for substrate inspection includes detector optics with high secondary electron detection efficiency combined with minimal distortion of the charged particle beam. One embodiment of the detector optics includes a symmetrizing electrode configured with a secondary electron detector to produce a generally cylindrically symmetric electric field about the optical axis of the column. Control electrodes may be used for screening the charged particle beam from the secondary electron detector and for controlling the electric field at the surface of the substrate. In some embodiments, the control electrodes are cylindrically symmetric about the optical axis; whereas in other embodiments, the cylindrical symmetry of one or more control electrodes is broken in order to improve the secondary electron detection efficiency.