A power supply supplies, to a chamber, periodic power for forming a gas supplied into the chamber into a plasma, a power level of the periodic power being changed for each period during one cycle. Circuitry is configured to detect an end point of a first etching based on at least one of a voltage, a current, or a phase difference between the voltage or the current measured by a sensor at a first timing during the one cycle. The circuitry is configured to detect an end point of a second etching based on at least one of a voltage, a current, or a phase difference between the voltage or the current measured by the sensor at a second timing different from the first timing during the one cycle.

Embodiments of this application discloses a plasma processing method performed in a plasma processing apparatus having a plurality of plasma sources, the plasma processing method comprising: controlling each of the plasma sources so that at least one plasma source of the plurality of plasma sources is in a first state referring an OFF-state or a power state of a first level and the remaining plasma sources are in a second state referring an ON-state or a power state of a second level higher than the power state of the first level; and generating plasma from a processing gas with power output from the plurality of plasma sources, and processing a substrate, wherein said controlling of each of the plasma sources includes repeatedly controlling so that the plasma source of the first state among the plurality of plasma sources is sequentially transitioned.

A substrate processing method for modifying a film formed on a substrate is provided. The method includes: forming a precoated film on the surface of a processing chamber by a plasma formed from a precoating gas using a microwave having a first power; preparing the substrate on a mounting table in the processing chamber; and modifying the film by irradiating the film with a hydrogen-containing plasma formed from a hydrogen-containing gas using a microwave having a second power lower than the first power.

In some aspects, the embodiments described herein relate to a method for tuning a frequency of microwave power delivered to a chamber, including striking a plasma in the chamber. Embodiments may further comprise scanning the frequency from a first frequency to a second frequency, where a set point frequency in a range from the first frequency to the second frequency has a lowest reflected power. In an embodiment, the method further includes setting the frequency of the microwave power delivered to the chamber to the set point frequency. The method may further include changing the set point frequency when a measure of reflected power exceeds a threshold.

A power supply assembly includes a plurality of microwave power supplies each designed to generate a microwave power signal for generating a plasma in a plasma process chamber, and a base including an upper face and a lower face. The microwave power supplies being arrangeable as an assembly on the upper face of the base. The base including plug contacts on the upper face, where the microwave power supplies include mating elements which match the plug contacts. The microwave power supplies being pluggable with the mating elements into the plug contacts of the base and being mechanically fastenable. At least one of the microwave power supplies being individually separable from the base while one or a plurality of the microwave power supplies are being operated. The base is designed to be attached with the lower face to a plasma process chamber upper face.