Ignition control method, film forming method, and film forming apparatus

An ignition control method comprising:

• providing a film forming apparatus including:
• a processing container configured to accommodate a substrate;
• a plasma box formed in the processing container;
• a pair of electrodes disposed in the processing container to sandwich the plasma box;
• and
• a radio-frequency (RF) power supply connected to the pair of electrodes via a matching box having a variable capacitor,
• the ignition control method further comprising:
• (a) setting, by a control unit, a process recipe, the process recipe defining at least one of (i) a frequency of the RF power supply, (ii) a type of gas supplied into the processing container, and (iii) an internal pressure or temperature of the processing container for specifying a processing condition of the substrate;
• (b) obtaining, by a sensor, first information representing a measured inter-electrode voltage between the pair of electrodes for each of a plurality of adjustment positions of the variable capacitor when a radio-frequency voltage of a first frequency is applied from the RF power supply at a power level insufficient to ignite plasma;
• (c) determining, by the control unit, a preset value of the variable capacitor based on the first information measured in (b);
• and
• (d) setting, by the control unit, an initial position of each of the variable capacitor corresponding to the preset value determined in (c).