Patent ID: 7439506

Claim:
An inspection method for detecting a defect of a specimen by using an electron beam, said method comprising th4 steps of: generating the electron beam; converging the electron beam on the specimen by an objective lens; applying a retarding voltage to the specimen for decelerating the electron beam; scanning the specimen by a converged electron beam; continuously moving a stage holding the specimen during scanning by the electron beam; measuring a height of the specimen during the stage continuously moves; dynamically correcting a focal distance of the objective lens in accordance with said measured height of the specimen; measuring a position of the stage during which the stage continuously moves for detecting a position of radiation of the electron beam on the specimen; controlling a position of radiation of the electron beam on the specimen in accordance with said detected position of radiation of the electron beam; detecting charged particles emanating from the specimen at a location between said specimen and said objective lens and converting said detected charged particles into an electrical signal; storing picture information conveyed by said electrical signal; comparing a picture with another by using said stored picture information; and detecting a defect of the specimen by said comparing step.