Plasma apparatus

A plasma apparatus comprising:

• a chamber;
• a first electrode a second electrode disposed in the chamber, the second electrode facing the first electrode;
• an RF power generator configured to apply non-sinusoidal wave power to the first electrode, wherein plasma is generated in the chamber in response to the non-sinusoidal wave power being applied to the first electrode;
• a measuring device disposed outside the chamber and configured to measure a voltage data over time and a current data over time of non-sinusoidal wave power that is applied from the RF power generator;
• and
• a controller configured to receive the voltage data over time and the current data over time from the measuring device, and calculate an extended impedance associated with the plasma based on the voltage data over time and the current data over time,
• wherein impedance calculated in a frequency domain of the non-sinusoidal wave power varies according to frequency, and
• the extended impedance has a single complex number value independent of the frequency, and is a weighted average of the impedance calculated in the frequency domain of the non-sinusoidal wave power with respect to a square of a current component.

A plasma apparatus comprising:

• a vacuum chamber provided with an upper electrode, to which power is applied, and a grounded lower electrode;
• an RF power generator configured to apply pulse power to the upper electrode, wherein plasma is generated between the upper electrode and the grounded lower electrode in response to the pulse power being applied to the upper electrode;
• a measuring device disposed outside the vacuum chamber and configured to measure voltage data over time, current data over time, and a pulse period value of the pulse power that is applied from the RF power generator;
• a matching circuit connected between the RF power generator and the measuring device to adjust impedance for transferring the pulse power;
• and
• a controller configured to:
• receive the voltage data over time, the current data over time, and the pulse period value,
• calculate an extended impedance associated with the plasma based on the voltage data over time, and the current data over time, and
• control the matching circuit based on the extended impedance,
• wherein an impedance calculated in a frequency domain of the pulse power varies with frequency, and the extended impedance has a single complex value that is independent of the frequency and represents the pulse power associated with a plurality of frequencies.