PLASMA PROCESSING APPARATUS AND PLASMA PROCESSING METHOD

摘要

A plasma processing apparatus (1) processes a wafer (W) that is contained within a processing vessel (2) by changing a processing gas introduced into the processing vessel (2) into a plasma. The plasma processing apparatus (1) is provided with a central introduction unit (55), a peripheral introduction unit (61), a flow rate adjustment unit and a control unit (49). The central introduction unit (55) introduces a processing gas that contains at least one of an Ar gas, an He gas and an etching gas to the central part of the wafer (W). The peripheral introduction unit (61) introduces the processing gas to the peripheral portion of the wafer (W). The flow rate adjustment unit adjusts the flow rate of the processing gas that is to be introduced from the central introduction unit (55) to the central part of the wafer (W) and the flow rate of the processing gas that is to be introduced from the peripheral introduction unit (61) to the peripheral portion of the wafer (W). The control unit (49) controls the flow rate of the processing gas to be adjusted by the flow rate adjustment unit so that the partial pressure ratio of the He gas relative to the Ar gas contained in the processing gas is at a predetermined value or more.