Method and apparatus for improved plasma processing uniformity

A plasma reactor system for processing a workpiece, comprising:

• a) a plasma chamber having sidewalls, an upper wall and a lower wall defining an interior region capable of supporting a plasma;
• b) a unitary electrode having a plurality of electrode regions, arranged within said interior region adjacent said upper wall;
• c) a RF multiplexer electrically connected to the plurality of electrode regions of said unitary electrode via a corresponding plurality of RF feed lines;
• d) corresponding to said plurality of RF feed lines;
• and
• e) a workpiece support member, arranged in the interior region adjacent said lower wall, for supporting the workpiece.

A method of determining a set of optimum plasma process parameters A*={n*, τi*, Φi*, Pi*, S*;

• Li*} for plasma processing, with a high degree of uniformity, a workpiece in a plasma reactor chamber having an electrode with an upper surface as part of a plasma reactor system, wherein n is the number of RF feed lines connected to the electrode upper surface at locations Li, τi is the on-time of the RF power for the ith RF feed line, Φi is the phase of the ith RF feed line relative to a select one of the other RF feed lines, Pi is the RF power delivered to the electrode to location Li through the ith RF feed line, and S is the sequencing of RF power to the electrode through the RF feed lines, the method comprising the steps of:
• a) setting initial values for process parameters n, ,τi, Φi, Pi, and S;
• and
• b) processing one or more workpieces while varying one or more of said process parameters to determine the optimized set of process parameters A*={n*, τi*, Φi*, Pi*, S*} that achieve a process non-uniformity less than a predetermined standard.

A method of determining a set of optimum plasma process parameters A*={n*, τi*, Φi*, Pi*, S*;

• Li*} for plasma processing, with a desired degree of uniformity, a workpiece in a plasma reactor chamber having an electrode with an upper surface as part of a plasma reactor system, wherein n is the number of RF feed lines connected to the electrode upper surface at locations Li, τi is the on-time of the RF power for the ith RF feed line, Φi is the phase of the ith RF feed line relative to a select one of the other RF feed lines, Pi is the RF power delivered to the electrode to location Li through the ith RF feed line, and S is the sequencing of RF power to the electrode through the RF feed lines, the method comprising the steps of:
• a) setting initial values for process parameters n, τi, Φi, Pi, and S;
• and
• b) processing one or more workpieces while varying one or more of said process parameters to determine the optimized set of process parameters A*={n*,τi*, Φi*, Pi*, S*} that achieve a desired process uniformity.