Thermal analysis of macroparticles during vacuum arc deposition of TiN

Plasma jet emitted from cathode spots of vacuum arcs can be used to prepare films such as titanium nitride. However, the deposited films suffer greatly from the contamination of so-called macroparticles (MPs), i.e. liquid micro-droplets from the cathode spots, Once spit from the cathode spot, MPs change their temperature before arriving at the substrate. This paper investigates the thermal equilibrium of the MPs during the flight from the cathode to the substrate. A model is set up and numerically solved to determine the temperature variation of titanium MPs in the TiN deposition process. The numerical results show that the temperature and radius of the MPs decrease during the flight to the substrate. When the MPs are small enough they will solidify before arriving at the substrate. The obtained TiN films are analyzed using scanning electron microscopy (SEM). The SEM photos of film morphology support the calculated results. (C) 1997 Elsevier Science S.A.