Effect of Gaseous Atmosphere on Particle Generation by Emitters for Corona Discharge Ionizers

摘要

A corona discharge air ionizer is one of the most useful devices for controlling electrostatic charges in ULSI manufacturing processes. However, a corona discharge air ionizer generates particles that act as contamination. Particle generation tests were carried out for a silicon emitter and a tungsten emitter in air, nitrogen and argon atmospheres. Deterioration at the tip of each emitter operated in each type of atmosphere was observed to investigate the relationship between the particle generation characteristics and the deterioration characteristics. The number of particles generated from the silicon emitter was smaller than that generated from the tungsten emitter in each type of atmosphere. The number of particles generated in argon and nitrogen atmospheres was lower than that in air. The silicon emitter in nitrogen and argon atmospheres generated about 200 times fewer particles than did the tungsten emitter in air. No deterioration was observed for the silicon emitter operated in nitrogen and argon atmospheres, while considerable deterioration was observed for the tungsten emitter operated in air.