Plasma treatment apparatus, power supply system and frequency control method

Abstract

The plasma processing apparatus disclosed in this invention includes a chamber, a substrate support, first and second power supplies, and a control circuit. The control circuit controls the first and second power supplies to supply a first bias signal and a second bias signal to the substrate support within the chamber in each of a plurality of repetition cycles. The control circuit adjusts the second frequency of the second bias signal within each of a plurality of sub-periods in each of the plurality of repetition cycles based on the impedance matching degree of the load of the second power supply in the same sub-period of the previous repetition cycle, thereby improving the matching degree.