Method and apparatus for tuning an RF matching network in a plasma enhanced semiconductor wafer processing system

A method of operating a matching network comprising:

• applying a first RF power to an antenna assembly to ignite a plasma;
• applying a second RF power to a matching network, where the matching network is coupled to a cathode pedestal within a plasma enhanced plasma reactor, the second RF power is applied in a CW mode;
• tuning matching parameters of the matching network during the CW mode;
• upon achieving a desired impedance match using the matching network, holding the matching parameters constant;
• and
• applying the second RF power in a pulsed mode.

Apparatus for operating a matching network comprising:

• an RF power source for applying RF power for a first period of time while matching parameters of a matching network are tuned to achieve a desired impedance match between an RF power source and a load;
• means for holding the matching parameters to values determined during the first period;
• and
• an RF power source for applying pulsed RF power to the matching network while the matching parameters are held constant.

A computer readable medium for storing software that, when executed by a computer, causes a semiconductor substrate processing system to perform a method of operating a matching network, comprising:

• applying RF power for a first period of time while matching parameters of a matching network are tuned to achieve a desired impedance match between an RF power source and a load;
• holding the matching parameters to values determined during the first period;
• and
• applying pulsed RF power to the matching network while the matching parameters are held constant.