Linear arc discharge (LAD): A new type of hollow cathode plasma source

A novel linearly scalable source for low pressure plasma processing is described. The source is based on a parallel plate hot hollow cathode in a focusing magnetic field which allows generation of a linearly uniform plasma in a gas admitted into the slit between the plates. Results of experiments with the laboratory prototype of 10 cm long linear are discharge (LAD) source supplied by a 13.56 MHz max. 2 kW radio frequency (r.f.) generator are presented. An r.f. impedance probe was used to characterize the discharge. The optical emission from Ar discharge along the slit between Ti cathode plates in the LAD was monitored to study production of Ti and Ti+ ions at different experimental characteristics, e.g. varying the r.f. power, gas flows and gas pressure. First results on Ti film depositions are presented. Experiments show that the discharge performance of the LAD source is similar to the r.f. hollow cathode plasma jet (RHCPJ). The LAD source can favorably extend RHCPJ abilities to large area processing.