ION SOURCE BLOCK FILAMENT WITH LABYRINTH CONDUCTIVE PATH

摘要

A filament plate for an ion beam source assembly of an ion implantation apparatus is disclosed. The filament plate is comprised of tungsten and incl udes two spaced apart spiral slits through a width of the plate. A gap width of the s lits in not substantially greater than ten times a plasma Debye length of ions generated by electrons emitted into an arc chamber. The plate filament is disposed in an arc chamber into which ionizable source materials are injected. The plate includ es two conductive posts press fit into openings of the plate for heating the plate to the thermionic emission temperature. The conductive posts extend through insulat ed openings in a side wall of the arc chamber.