An investigation of the pulsed plasma for deposition of thin film materials

A new technology for generating pulsed plasma was developed for the deposition of thin film materials according to the concept of the coaxial plasma gun. A model has been developed to describe the generation and acceleration of pulsed plasma. Diagnostic measurements were carried out to understand the basic process of generation of pulsed plasma by using the electric probes and mass spectroscopy. It was found that the plasma density and composition strongly depend on the discharging voltage and inner-electrode materials. The electron density for a titanium inner-electrode is higher than that for a graphite inner-electrode. Typical values for the electron density for the pulsed plasma are n(e) = 10(14) for graphite innerelectrode and 10(15) cm(-3) for titanium inner electrode. The electron temperature is T-e = 65 eV. The velocity of pulsed plasma increases proportionally with discharging voltage. The pulsed plasma mainly consists of two kinds of ions: working gas ions and inner-electrode ions. The ratio between two kinds of ions depends on the inner-electrode materials and the discharging voltage. The ion amounts of the inner-electrode, which has low conductivity, are much lower than that of working gas and have no relationship with discharging voltage. However, if the inner-electrode is made of metal materials with good conductivity, the plasma amounts of two kinds of ions can be compared with each other. The pursed plasma-material interaction is also discussed in detail. (C) 1998 Published by Elsevier Science S.A.