Patent ID: 8847158

Claim:
A method for measuring the surface charge distribution of a sample, comprising: a charging step of irradiating the sample with a charged particle beam and charging a surface of the sample in a spot-like manner; a first measuring step of irradiating the charged sample with the charged particle beam to measure a value of a potential at a potential saddle point formed above the sample; a selecting step of selecting one structure model from preset multiple structure models and selecting a tentative space charge distribution associated with the one structure model; a first calculating step of calculating a space potential at the potential saddle point by electromagnetic field analysis using the selected structure model and tentative space charge distribution; a determining step of comparing the calculated space potential and the measured value to determine the tentative space charge distribution as a space charge distribution of the sample when an error between the space potential and the measured value is within a predetermined range; and a second calculating step of calculating a surface charge distribution of the sample by electromagnetic field analysis based on the determined space charge distribution of the sample.