METHODS AND APPARATUSES FOR CONTROLLING TRANSITIONS BETWEEN CONTINUOUS WAVE AND PULSING PLASMAS

摘要

Provided are methods and apparatuses for smoothly transitioning from a first plasma condition to a second plasma condition in a plasma processing chamber. An apparatus for plasma processing may be equipped with an RF power supply coupled to an impedance matching network to smoothly switch from a continuous wave (CW) plasma to a pulsing plasma, reversely, or in alternation without quenching the plasma. Or, the plasma processing chamber may be equipped to smoothly switch from a pulsing plasma at a first duty cycle to a pulsing mode at a second duty cycle without quenching the plasma. Such transitions may occur by ramping RF power, ramping duty cycle, and/or ramping pulsing frequency of the RF power supply being delivered to the plasma processing chamber so that impedance can be smoothly changed and matched by the impedance matching network during the transitions.