PLASMA PROCESSING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a plasma processing apparatus capable of quickly and highly accurately controlling pressure in a vacuum processing chamber.SOLUTION: A plasma processing apparatus includes: a vacuum processing chamber; a high frequency power supply for supplying high frequency power for generating plasma; a gas supply unit for supplying gas to the inside of the vacuum processing chamber; an exhaust unit for exhausting air from the vacuum processing chamber; a conductance control valve for controlling an exhaust speed of the exhaust unit; a pressure gauge arranged between the exhaust unit and the conductance control valve; and a control device for controlling the conductance control valve so that pressure in the vacuum processing chamber becomes desired pressure. The control device finds out a flow rate which is a product of the pressure measured by the pressure gauge and an exhaust speed and the flow rate of air exhausted from the exhaust unit, finds out conductance by using a difference between desired pressure and the pressure measured by the pressure gauge and the flow rate, and controls an aperture of the conductance control valve to an aperture corresponding to the conductance.