COLD CATHODE FIELD EMISSION ELECTRON GUN AND ITS APPLICATION TO ELECTRON BEAM INSTRUMENTS

摘要

The present invention provides an electron beam instrument in which variation of the trajectory of the electron beams can be suppressed even when the voltage applied to the first extractor electrode is controlled in order to stabilize the emission current amount of the electron beams. The electron beam instrument has a cold cathode field emission electron gun. The cold cathode field emission electron gun has a cold cathode, a first extractor electrode and a second extractor electrode. Distance between the cold cathode and the first extractor electrode is set to be shorter than distance between the first extractor electrode and the second extractor electrode. Voltage applied to the first extractor electrode is increased when current amount of the electron beams emitted from the cold cathode is attenuated.