| 摘要 |
PROBLEM TO BE SOLVED: To obtain an energy filter image with a same irradiation condition without changing beam position, beam tilt angle, irradiation current amount, beam diameter, etc., on a sample surface even if offset voltage is overlapped with accelerating voltage. SOLUTION: A lens current value Ic' of focus lens system when an offset voltage is overlapped, the lens current value Ic of focus lens system when a coil current value Id' of an irradiation deflecting coil is not overlapped with the offset voltage, a coil current value Id of the irradiation deflecting coil, value E which has been relativistically corrected for accelerating voltage when there is no overlapping of the offset voltage, and a value E' which has been relativistically corrected for the accelerating voltage when there is overlapping of the offset voltage are used, the current value of focus lens system and irradiation deflecting coil is changed so as to be represented by Ic'=Ic.√E'/√E, 1d'=Id.√E'/√E.
|
