| 摘要 |
PROBLEM TO BE SOLVED: To reduce the occurrence of foreign matters in an electrode plate for plasma etching, by forming the plasma face-side end sections or both end sections of a plurality of through holes formed through the electrode plate in tapered shapes having large-diameter sections at the ends of the holes. SOLUTION: A plurality of through holes formed through an electrode plate for plasma etching for blowing an etching gas are formed to have tapered end sections having large-diameter sections at the ends of the holes. At the time of forming the tapered end sections, the surface of the electrode plate around the through holes is polished with a loose abrasive of alumina, cerium oxide, etc. Consequently, foreign matters are prevented from falling down from the electrode plate, because the concentration of discharge to the surface of the electrode is prevented and the local wear of the electrode surface is eliminated. Since the end sections of the through holes on the rear surface of the electrode plate which comes into contact with a back plate are formed in the tapered shapes, the etching gas is made to flow smoothly and the creeping of plasma can be suppressed. In addition, the amount of resulted deposits of reaction can be reduced and the deposits can be prevented from coming off the electrode plate and falling onto a wafer. |
