Patent ID: 8313805
Filing Date: 2012-11-20
Classification: H01J

Abstract:
1. A method of treating a semiconductor substrate in a capacitively coupled plasma chamber having upper and lower electrodes wherein the upper electrode comprises a showerhead electrode assembly of a capacitively coupled plasma processing chamber, comprising: a thermal control plate supported by a temperature controlled top wall of the plasma processing chamber, the thermal control plate having a diameter larger than a wafer to be processed in plasma processing chamber and including at least one gas plenum in a lower face thereof; a backing plate supported by the thermal control plate, the backing plate having a diameter smaller than the thermal control plate, gas passages extending vertically therethrough and communicating with the at least one gas plenum and rotatable cam locks in bores extending horizontally into an outer periphery of the backing plate; a guard ring surrounding the backing plate, the guard ring including at least one horizontally extending access bore passing through the guard ring, the guard ring being rotatable around the backing plate to align the access bore with at least one of the cam locks; an inner electrode having gas passages extending vertically therethrough in fluid communication with the gas passages in the backing plate, an outer periphery of the inner electrode including inner and outer steps, the outer step being located between the inner step and a surface of the inner electrode facing the backing plate; a clamp ring having an inner flange overlying the outer step of the inner electrode with an optional compression ring therebetween, the clamp ring including vertically extending stepped openings, the stepped openings being aligned with threaded holes in the backing plate and fasteners in the stepped openings attaching the clamp ring to the backing plate; and an outer electrode surrounding the inner electrode and including vertically extending locking pins which engage the cam locks, the outer electrode supporting the guard ring and being removable by releasing the locking pins from the cam locks, said method comprising the steps of: supporting the semiconductor substrate on the lower electrode; supplying process gas to the chamber; energizing the process gas into a plasma state by supplying RF energy between the upper and lower electrodes; and processing the semiconductor substrate with the plasma.