Abstract: A host computer controlling a secondary optical system under such an image focusing condition that secondary beams obtained from an arbitrary region on a substrate form an image on a MCP detector, in accordance with a correlation between a state of the substrate and an energy of the secondary electrons and the reflected electrons upon the secondary optical system, in which the energy of the secondary electron beams is various depending on the state of the substrate. The host computer also measures quantitatively a physical and/or chemical characteristic of the substrate on a basis of the image focusing condition and the image signals.

Abstract: There is here disclosed charged particle beam apparatus in which reactant floating in vacuum can efficiently be removed by simple structure. The charged particle beam apparatus of the present invention comprises a pulse tube refrigerator, a refrigerator controller for controlling the refrigerator, a compressor, a high-pressure rotary valve, a low-pressure rotary valve, and an active damper for removing vibration generated in the refrigerator. Since a cold section is disposed between an objective lens and a specimen in a vacuum container, and adsorbs the reactant in the vacuum container, the amount of reactant in the vacuum container can be reduced, the errors of the critical dimension value of a critical dimension SEM are reduced, and measurement precision is improved. Moreover, since a pulse tube is used as the refrigerator for cooling the cold section, the structure of the apparatus can be simplified and miniaturized.