PLASMA PROCESSING APPARATUS, PLASMA PROCESSING METHOD AND CLEANING TIME PREDICTION PROGRAM

摘要

The plasma processing apparatus relating to the present invention has a measurement circuit for measuring an antenna bias voltage that varies according to an amount of electrical charge between an inner wall of a chamber and plasma generated in the chamber. The obtained antenna bias voltage is converted to a statistical value and is stored in a statistical value memory unit after being associated with a number of particles attached on a workpiece during the same plasma processing that the antenna bias voltage is obtained. A correspondence acquisition unit obtains a correspondence the antenna bias voltage and the number of particles based on stored data in the statistical value memory. Then, a prediction unit predicts the antenna bias voltage at which the number of particles reaches to a pre-determined value based on the correspondence obtained by the correspondence acquisition unit.