Patent ID: 7095031
Filing Date: 2006-08-22
Classification: H01J

Abstract:
1. A method of automatically correcting aberrations in a charged-particle beam, comprising: a step for extracting line profiles from a probe profile of the charged-particle beam when it has been defocused; a step for calculating amounts of features μ, σ, and ρ from the extracted line profiles, the μ, σ, and ρ indicating features of the line profiles, i.e., left-and-right asymmetry, width, and unevenness around the center; a step for calculating amounts of aberrations in the charged-particle beam from the a mounts of features μ, σ, and ρ; a step for making a decision as to whether a total amount of aberration in the charged-particle beam calculated based on the amounts of aberrations is less than a given threshold value; and a step for specifying at least one of the amounts of aberrations, calculating an amount of feedback for reducing the specified amount of aberration, and correcting the aberrations in the charged-particle beam based on the amount of feedback when the total amount of aberration has been judged to be greater than the threshold value by the step for making a decision.