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:
Nov. 25, 2003
Filed:
Jul. 06, 2001
Hiroshi Nishimura, Kawasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A main control system prepares, in advance, a voltage map showing the amount of focus deviation of a secondary electron beam B at a detection surface of an electron beam detector corresponding with the amount of charge-up generated on a sample upon irradiation with a primary electron beam B and stores this voltage map in a storage device During an observation, the main control system reads the voltage map stored in the storage device and corrects the focal position of the secondary electron beam B by controlling either the voltage applied to the secondary optical system or the voltage applied to the sample As a result, focal position deviations resulting from charge-up generated on the sample being observed can be corrected without causing inconvenience to an operator.