Method of calibrating beam position in charged-particle beam system

摘要

A method of calibrating the beam position in a charged-particle beam system starts with finding a focus deviation on the material surface for each point within a deflection field. A focus correction voltage V_F necessary to cancel out the focus deviation is determined. A beam position deviation f_i per unit focus correction voltage is found. The deflection voltage is corrected so as to cancel out the product f_i·V_F. The deflection voltage is corrected so as to cancel out the sum of the product f_i·V_F and the measured deflection field distortion while correcting the focus based on the voltage V_F.