CPC H01J 37/32715 (2013.01) [H01J 37/32146 (2013.01); H01J 37/32568 (2013.01); H01L 21/6831 (2013.01); H01J 2237/2007 (2013.01); H01J 2237/3341 (2013.01)] | 15 Claims |
1. A plasma processing chamber, comprising: a substrate support assembly, comprising:
a substrate supporting surface;
a first biasing electrode;
a first dielectric layer disposed between the first biasing electrode and the substrate supporting surface;
a waveform generator configured to generate a plurality of pulsed voltage waveforms during a first time period and halt generation of the plurality of pulsed voltage waveforms during a second time period;
a first power delivery line that electrically couples the waveform generator to the first biasing electrode, wherein the first power delivery line comprises a blocking capacitor;
a clamping network coupled to the first power delivery line at a first point between the blocking capacitor and the first biasing electrode, the clamping network comprising:
a direct-current (DC) voltage source coupled between the first point and ground; and
a blocking resistor coupled between the first point and an output of the DC voltage source; and
a controller configured to:
receive, during the first time period and the second time period, information within a first electrical signal obtained via a first signal trace coupled to the first point, wherein the information within the first electrical signal obtained during the first time period comprises a portion of a waveform of the plurality of pulsed voltage waveforms that comprises a first voltage level, and wherein the information within the first electrical signal obtained during the second time period comprises a second voltage level;
compare the first voltage level with the second voltage level; and
control a magnitude of a voltage the DC voltage source supplies to the first point of the first power delivery line based on comparing the first voltage level with the second voltage level.
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