Scanning charged particle microscope, and focal distance adjusting method and astigmatism correction method thereof

摘要

In order to provide a method to easily and surely adjust the focal distance as in a Wobbler apparatus of the transmission type electron microscope method, a crossover 11 of a charged particle beam 2 is established between a charged particle gun 1 and an objective lens 6 and a beam deflection device 4 is provided to deflect the charged particle beam at the crossover point as the supporting point. A total controller 9 calculates an amount of the out of focus from a moving amount of the microscopic image obtained by deflecting the beam and orders the objective lens power supply to move the microscopic image as the focal distance.