Method and apparatus for pulsed plasma processing using a time resolved tuning scheme for RF power delivery

A method for tuning a system operating a plasma process using a source RF power supply and a bias RF power supply, each capable of frequency tuning and respectively coupled to a process chamber via a source matching network and a bias matching network, the method comprising:

• igniting a plasma in a process chamber using the source RF power supply and the bias RF power supply, each set in a continuous wave mode and in a fixed frequency mode, with the source matching network and the bias matching network each set in an automatic tuning mode;
• changing the source matching network to hold mode while keeping the bias matching network in automatic mode after the matching networks adjust to reduce reflected power from both the source and the bias RF power supplies;
• turning on frequency tuning for the source RF power supply while keeping it off for the bias RF power supply;
• turning on a pulsing mode for the source RF power supply and/or the bias RF power supply;
• and
• placing the bias RF power supply in frequency tuning mode.

A method for tuning a system operating a plasma process in a time resolved manner using a source RF power supply and a bias RF power supply, each capable of frequency tuning and respectively coupled to a process chamber via a source matching network and a bias matching network, the method comprising:

• igniting a plasma in a process chamber using the source RF power supply and the bias RF power supply, each independently set in a first operational mode selected from either a continuous wave mode or a pulsing mode and in a first tuning mode selected from either a fixed frequency mode or a frequency tuning mode, with the source matching network and the bias matching network each independently set in a first match mode selected from either an automatic tuning mode or a hold mode;
• upon expiration of a first period of time, switching the first operational mode of one or both of the source RF power supply and the bias RF power supply;
• upon expiration of a second period of time, switching the first tuning mode of one or both of the source RF power supply and the bias RF power supply;
• and
• upon expiration of a third period of time, switching the first match mode of one or both of the source matching network and the bias matching network;
• wherein the first, second, and third periods of time are selected to reduce a reflected power reflected back to the source RF power supply and the bias RF power supply.