High-frequency power supply device and output method of high-frequency power

A high-frequency power supply device comprising:

• a high-frequency generation unit that generates a first high-frequency signal and a second high-frequency signal;
• a control unit that periodically controls amplitudes or phases of the first high-frequency signal and the second high-frequency signal which are generated by the high-frequency generation unit;
• a first high-frequency output unit that outputs high-frequency power, magnitude of which is controlled on the basis of the first high-frequency signal, the amplitude or phase of which is controlled by the control unit;
• and
• a second high-frequency output unit that outputs high-frequency power, magnitude of which is controlled on the basis of the second high-frequency signal, the amplitude or phase of which is controlled by the control unit,
• wherein the control unit controls the amplitude or phase of the first high-frequency signal such that the magnitude of the high-frequency power output by the first high-frequency output unit is a first level in a first period of a control cycle,
• the control unit controls the amplitude or phase of the second high-frequency signal such that the magnitude of the high-frequency power output by the second high-frequency output unit is a second level in a second period of the control cycle which is different from the first period, the second level being lower than the first level,
• the control unit gradually decreases or increases at least one of the second level and a ratio of a length of the first period to a length of the control cycle,
• in a case in which the at least one of the second level and the ratio is gradually decreased, the control unit gradually increases the first level such that an average value of a synthesis of the high-frequency powers output by the first high-frequency output unit and the second high-frequency output unit is constant, and
• in a case in which the at least one of the second level and the ratio is gradually increased, the control unit gradually decreases the first level such that the average value of the synthesis of the high-frequency powers output by the first high-frequency output unit and the second high-frequency output unit is constant.

An output method of high-frequency power, magnitude of which is controlled on the basis of a high frequency signal, an amplitude or phase of which is controlled periodically, the output method comprising:

• controlling the amplitude or phase of the high-frequency signal such that the magnitude of the high-frequency power is a first level in a first period of a control cycle and is a second level in a second period of the control cycle which is different from the first period, the second level being lower than the first level;
• gradually decreasing or increasing at least one of the second level and a ratio of a length of the first period to a length of the control cycle;
• gradually increasing the first level such that an average value of the high-frequency power is constant in a case in which the at least one of the second level and the ratio is gradually decreased;
• and
• gradually decreasing the first level such that the average value of the high-frequency power is constant in a case in which the at least one of the second level and the ratio is gradually increased.