PLASMA PROPERTIES AT THE TRANSITION FROM REMOTE TO DIRECT PLASMA

R-PECVD reactors offer many advantages for the deposition of thin film s. However, high-energy ion bombardment of the substrate can only be a voided if the plasma parameters pressure and power are carefully chose n. In order to develop a simple criterion to distinguish remote from d irect plasmas, nitrogen and argon plasmas at pressures of 0.1-0.5 mbar and 0.3-0.8 mbar, respectively, have been investigated by a retarding field energy analyser and Langmuir probes. With increasing power, the mean ion energy of remote plasmas stays constant up to the remote-dir ect transition. The sudden increase of the mean ion energy at this poi nt proved to be a simple criterion to classify a plasma. This criterio n holds for capacitive as well as inductive coupling. (C) 1998 Elsevie r Science S.A.