Abstract: The plasma dry cleaning rate of semiconductor process chamber walls can be improved by placing a non-gaseous dry cleaning enhancement material in the position which was occupied by the workpiece during semiconductor processing. The non-gaseous dry cleaning enhancement material is either capable of generating dry cleaning reactive species and/or of reducing the consumption of the dry cleaning reactive species generated from the plasma gas feed to the process chamber.When process chamber non-volatile contaminant deposits are removed from plasma process chamber surfaces during plasma dry cleaning by placing a non-gaseous source of reactive-species-generating material within the plasma process chamber, the non-gaseous source of reactive-species-generating material need not be located upon or adjacent the workpiece support platform: however, this location provides excellent cleaning results in typical process chamber designs.

Abstract: A composite diagnostic wafer containing a placebo wafer having the same dimensions as a semiconductor wafer. The placebo wafer has affixed to one surface one or more ion current probes and one or more ion energy analyzers. As such, measurement instrumentation connected to the analyzer(s) and probe(s) determines ion current and ion energy at various locations on the placebo wafer during plasma generation within a semiconductor wafer processing system.

Abstract: A wafer clamping mechanism includes a clamp ring having a central opening corresponding to the geometry of a conventional semiconductor wafer. An overhang located about the opening engages the corresponding semiconductor wafer when in place on an electrode of a plasma reactor. The clamp ring is resiliently mounted on a housing which holds a second electrode. The clamp ring is automatically engaged against the wafer as the spacing between the two electrodes is adjusted to a desired gap width. A raised annular barrier on the lower electrode circumscribes the wafer and engages a mating surface on the clamp ring in order to enhance alignment of the clamp.

Abstract: A plasma etching system includes a radio frequency generator and a parallel plate plasma reactor vessel. A phase inverter circuit is used to couple the RF generator to the electrodes in the plasma reactor so that the electrodes are driven with voltages of substantially equal magnitude but which are 180.degree. out-of-phase. In this way, a maximum potential difference between the electrodes can be achieved while minimizing the potential difference between the individual electrodes and the reactor vessel. Such operation allows higher power levels with reduced occurrence of arcing and stray discharge, and provides a stable, uniform plasma discharge.