This paper presents a refined model for the generation of a supersonic
plasma jet by a hollow cathode discharge inside the nozzle of a low p
ressure r.f. plasma chemical reactor. Through the nozzle which is plac
ed in the r.f. electrode the working gas flows to the reactor chamber.
If at the outlet of the nozzle the gas flow is supersonic, a well-def
ined plasma jet is created inside the reactor chamber. The application
of this system for the deposition of germanium nitride thin films is
shown.