SCANNING TYPE CHARGED PARTICLE MICROSCOPE, METHOD OF FOCUSING IT AND METHOD OF COMPENSATING ITS ASTIGMATISM

摘要

PROBLEM TO BE SOLVED: To provide a method of enabling simple and reliable focusing like a wobblier device in a transmission electron microscope method. SOLUTION: A crossover 11 is provided between a charged particle gun 1 and an objective lens 6, and a deflector 4 to deflect a charged particle beam with the crossover as a fulcrum is provided. An overall controller 9 computes an unfocused quantity from the movement of a microscope image caused by beam deflection, and commands to the power source of the object lens to deflect a focus distance.