Effect of gaseous atmospheres on particle generation from emitters for corona discharge ionizers

摘要

A corona discharge air ionizer is one of the most useful equipment to control electrostatic charges in ULSI manufacturing processes. However, a corona discharge air ionizer generates particles that act as contamination. Particle generation test was carried out for the silicon emitter and the tungsten emitter in the air, the nitrogen and the argon atmospheres. The deterioration at the tip of the emitter was observed, because the number of particle generation relates closely to the deterioration, The number of particle generation from the silicon emitter was lower than that from the tungsten emitter for each atmosphere. The number of particle generation in the argon and the nitrogen atmosphere was lower than that in the air atmosphere. The number of particle generation for the silicon emitter in the nitrogen and the argon atmosphere was about 200 times lower than that of the tungsten emitter in air atmosphere. Non-deterioration was observed for the silicon emitter operated in the nitrogen and the argon atmosphere, while remarkable deterioration was observed for the tungsten emitter operated in the air atmosphere.