摘要 |
A charge control electrode emitting photoelectrons is disposed just above a wafer (sample) in parallel thereto, and the electrode has a through hole so that ultraviolet light can be irradiated to the wafer through the charge control electrode. Specifically, a metal plate which is formed in mesh or includes one or plural holes is used as the charge control electrode. By disposing the charge control electrode just above the sample in parallel thereto, when negative voltage is applied to the electrode, electric field approximately perpendicular to the wafer is generated. Therefore, photoelectrons are efficiently absorbed in the wafer. Also, by using the charge control electrode having approximately the same size as that of the wafer, charges on a whole surface of the wafer can be removed collectively and uniformly. Therefore, time required for the process can be reduced.
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