Plasma generation device, substrate processing apparatus, and method of manufacturing semiconductor device

A substrate processing apparatus, comprising:

• a process chamber in which a substrate is processed;
• a gas supplier configured to supply a predetermined process gas into the process chamber;
• and
• a plasma generation device comprising:
• a plurality of high-frequency power sources configured to supply power to a plurality of plasma generators, respectively;
• and
• a plurality of matchers installed between the plurality of high-frequency power sources and the plurality of plasma generators, and configured to respectively match load impedances of the plasma generators with output impedances of the high-frequency power sources,
• wherein at least one high-frequency power source of the plurality of high-frequency power sources comprises:
• a high-frequency oscillator configured to oscillate a high-frequency;
• a directional coupler disposed at a subsequent stage of the high-frequency oscillator, and configured to extract a part of a traveling wave component from the high-frequency oscillator and a part of a reflected wave component from a corresponding matcher of the plurality of matchers;
• a filter configured to remove a noise signal included in the reflected wave component extracted by the directional coupler;
• and
• a power monitor configured to:
• measure the reflected wave component after passing through the filter and the traveling wave component extracted by the directional coupler and then passed through the filter;
• and
• feedback-control the corresponding matcher to reduce a ratio between the reflected wave component and the traveling wave component measured by the power monitor, and
• wherein the plurality of plasma generators includes buffer structures configured to generate plasma, respectively, and each of the buffer structures includes two first electrodes connected to the high-frequency power source and a second electrode that is disposed between the two first electrodes and grounded.