Methods and apparatuses for controlling gas flow conductance in a capacitively-coupled plasma processing chamber

摘要

Apparatuses are provided for controlling flow conductance of plasma formed in a plasma processing apparatus that includes an upper electrode opposite a lower electrode to form a gap therebetween. The lower electrode is adapted to support a substrate and coupled to a RF power supply. Process gas injected into the gap is excited into the plasma state during operation. The apparatus includes a ground ring that concentrically surrounds the lower electrode and has a set of slots formed therein, and a mechanism for controlling gas flow through the slots.