Patent ID: 7759653
Filing Date: 2010-07-20
Classification: H01J

Abstract:
1. An electron beam apparatus for examining defects on a semiconductor wafer device, the apparatus comprising: an electron source for generating a primary electron beam, wherein the total acceleration potential is divided and is provided across the ground potential; at least one condenser lens for pre-focusing the primary electron beam; an aperture for confining the primary electron beam to ameliorate electron-electron interaction, wherein the aperture is positioned right underneath the last condenser lens; a SORIL objective lens system for forming immersion magnetic field and electrostatic field to focus the primary beam onto the specimen in the electron beam path; a pair of grounding rings for providing virtual a ground voltage potential to those components within the electron beam apparatus installed below a source anode and above a last polepiece of the SORIL objective lens; at least one pair of deflectors for deflecting the primary electron beam over the specimen surface to form a scanning pattern; a detection system for detecting signal electrons; and a stage to hold the specimen to be inspected.