A substrate processing system that includes a ceramic substrate holder
having an RF electrode embedded within the substrate holder and a gas
inlet manifold spaced apart from the substrate holder. The gas inlet
manifold supplies one or more process gases through multiple conical holes
to a reaction zone of a substrate processing chamber within the processing
system and also acts as a second RF electrode. Each conical hole has an
outlet that opens into the reaction zone and an inlet spaced apart from
the outlet that is smaller in diameter than said outlet. A mixed frequency
RF power supply is connected to the substrate processing system with a
high frequency RF power source connected to the gas inlet manifold
electrode and a low frequency RF power source connected to the substrate
holder electrode. An RF filter and matching network decouples the high
frequency waveform from the low frequency waveform. Such a configuration
allows for an enlarged process regime and provides for deposition of
films, including silicon nitride films, having physical characteristics
that were previously unattainable.