| 摘要 |
PURPOSE:To suppress the fluctuation of electron beams owing to charge-up by providing means to heat the plane of incidence through which reflected electron beams enter an electron detector and re-evaporating organic substances sticked to the plane of incidence. CONSTITUTION:The tip of the transparent glass 31 of a reflected electron beam detector is covered by a thin heater film 32, and the side faces of the transparent glass 31 are covered by thin conductive electrode films 33a and 33b. Further, the surface of the thin heater film 32 is covered by a scintillator 34. And the tip and the sides of the glass part 31 are covered by an aluminium film 36. A photomultiplier 42 is arranged to detect fluorescent light. Transparent oxides of tin, indium, etc., are used for the thin heater film 32. Organic substances collected on the aluminium film 36 on the tip of the detector can be re-evaporated by flowing current through the thin heater film 32 and raising its temperature to, for example, 250-300 deg.C, to keep the aluminium film 36 clean, and so the charge-up can be removed. |
