SHORT-TIME INVESTIGATION OF LASER AND ARC-ASSISTED DEPOSITION PROCESSES

In both pulsed laser deposition (PLD) and vacuum are deposition (VAD) the target material is evaporated and ionised in an explosive process of some nanoseconds duration. In PLD the explosive evaporation is caus ed by very high power densities (10(7) to 10(10) W cm(-2)) which can b e produced by a highly focused laser beam. Nearly the same energy dens ity occurs automatically in the self-contracting current channel of th e Vacuum are. Owing to the high energy density, the plasmas of both so urces are highly ionised and the ions have kinetic energies of about 1 0 eV. A large part of the eroded material is emitted as molten droplet s. To improve the quality of deposited films, the proportion of drople ts should be reduced. Moreover, to expand its area of application, the energetic efficiency of PLD should be increased. To solve these probl ems, the processes of explosive plasma production must be studied with an adequate temporal and spatial resolution (of the order of nanoseco nds and micrometres). Owing to the insufficient resolution of the high -speed cameras available, a new system was especially designed for thi s task. This new high-speed framing camera HSFC, developed by PCO Comp uter Optics, combines a microscopic resolution of 5 mu m with a nanose cond time resolution and a very high optical sensitivity. In the prese nt paper, the first results are reported of the current programme of h igh-speed investigations of the explosive evaporation processes in PLD and are deposition.