ELECTRON BEAM GUN FOR USE IN AN ELECTRON BEAM EVAPORATION SOURCE

摘要

The present invention provides an electron beam gun for an electron beam evaporation source in which a beam former shields a filament from an anode such that electrons emitted from the filament are accelerated past the anode in a ribbon-like beam. The filament is connected to a split cathode block having two sides for applying an electric current through the filament. The beam former has two sections which are separately connected to the two sides of the cathode block such that the cathode block acts as a heat sink for the beam former, and a thermal gradient is not produced within the beam former that would produce warpage and movement of the beam former. Preferably, the vertical gap is about 0.254 mm. to prevent electrons emitted from the filament from arcing through the gap to the anode.