Cathode sputtering in inert-gas glow discharges

Measurements have been made of the rate of deposition of sputtered molybdenum films in the abnormal glow discharge in inert gases over the pressure range 3-21 mm Hg, as a function of the gas pressure p and the current i through the discharge tube. The rate of sputtering was found to be proportional to ( i / p ) 2.5 in both neon and the Penning mixture 99% neon-1% argon. In helium sputtering was negligible, but the addition of only a trace of neon caused appreciable sputtering to occur.