| 摘要 |
PURPOSE: To provide a charged particle beam device using a superimposed field lens, capable of making aberration on an axis extremely small. CONSTITUTION: When a primary electron beam EB on or near an optical axis reaches near an objective lens 1, by the lens functions of an accelerating part of an electric field constituted with electrodes 6, 7 and a decelerating part of an electric field constituted with electrodes 7, 8, the electron beam EB is deflected in the axial direction. By applying the voltage slightly lower than the accelerating voltage of the electron beam to a specimen 2, electrostatic potential attenuates along the axial, and by deceleration of the electron beam, aberration on axis of spherical aberration Cs and color aberration Cc is decreased by the deceleration of the electron beam. By this constitution, a gapαin the axial direction between the tip of an outside magnetic pole 3 of the objective lens 1 and the tip of an inside magnetic pole 4 is adjusted so that peaks of an electrostatic potential E and a magnetic potential B interfere each other to the specimen and the electron beam is most converged in the axial direction.
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