Patent ID: 7247848
Filing Date: 2007-07-24
Classification: G01N,H01J

Abstract:
1. An electron beam apparatus for evaluating a sample surface comprising: a multi-beam generator for generating a plurality of primary electron beams; a primary electro-optical system for irradiating the sample by the plurality of primary electron beams; a scanning deflector for scanning the primary electron beams on the sample; a plurality of detectors for detecting a plurality of secondary electron beams emitted from the sample by irradiation of the primary electron beams and for transducing the secondary electron beams to signals; a secondary electro-optical system for directing the secondary electron beams to the detectors, wherein the primary electro-optical system and the secondary electro-optical system have a common objective lens, a plurality of amplifiers provided at a down stream to outputs of the detectors respectively; and an adjusting device for adjusting gains and/or offsets of the amplifiers to correct the signals for non-uniformity.