High-Frequency Power Supply, Plasma Processing Device, and Matching Method

A plasma processing apparatus comprising:

• a chamber;
• a high-frequency power supply configured to generate a high-frequency power having a variable frequency to produce plasma in the chamber;
• a sensor configured to specify a reflection coefficient of the high-frequency power for a load connected to the high-frequency power supply;
• and
• a controller configured to determine a matching frequency of the high-frequency power for the load,
• wherein the controller is configured to:
• (i) obtain three reflection coefficients corresponding to a first frequency, a second frequency, and a third frequency from the sensor by using the first frequency, the second frequency, and the third frequency that are different from each other as frequencies of the high-frequency power;
• (ii) determine, as the matching frequency, a frequency of a minimum point of a quadratic function that expresses the relationship between the first to third frequencies and the three reflection coefficients;
• and
• (iii) control the high-frequency power supply to generate the high-frequency power having the matching frequency.