METHOD FOR DETERMINING PROCESSING GAS FLOW RATE

摘要

PROBLEM TO BE SOLVED: To provide a method for determining a processing gas flow rate, capable of reducing and preventing ground contamination caused by metal generated due to cleaning discharge.SOLUTION: Disclosed is a method for determining a processing gas flow rate in cleaning discharge of a plasma treatment apparatus including: a treatment chamber 101; gas supply means 150; a stage electrode 104; and an earth 130 covered with insulative ceramics. When the diffusion coefficient of a metal element constituting the surface of the stage electrode is D, the average distance between a workpiece placement surface and the earth is L, and the staying time of processing gas in a plasma discharge space is Tg, the flow rate of the processing gas is determined so as to satisfy the formula of T≤L/(2×D).