SUPERIMPOSED PULSE BIAS VOLTAGE USED IN ARC AND SPUTTER TECHNOLOGY

The superimposed pulsed bias voltage is composed of a d.c. ground voltage and a higher d.c. pulse voltage. The value of the pulse voltage is comparable with the level which is normally used for etching or sputtering; the ground voltage has the same level as used in conventional processes. Using a superimposed pulsed bias voltage in ion-assisted physical vapour deposition processes effects an additional ion bombardment to the surface with ions of higher energy. Both metal and reactive or neutral gas ions are accelerated to the surface. Basic principles and important characteristics of this newly developed process, such as surface processes and deposition results, are discussed. Because of the pulsing of the high voltage, the deposition temperature does not increase much. Adhesion, microstructure, morphology, internal stresses and film uniformity are influenced by these additional ion impacts. Different films (TiN on steel, copper on silicon or plastics) produced by arc and sputter technology are investigated.