Theory of Cathode Sputtering in Low Voltage Gaseous Discharges

Abstract

To determine the amount of sputtering in a glow discharge three functions must be known: the number of ions of a given energy striking the cathode, the amount of cathode material released from the cathode by each ion, and the fraction of material released from the cathode which diffuses away. Expressions derived for these allow determination of the dependence of total rate of sputtering on the geometry of the discharge, pressure, cathode fall, current, and constants of the gas and cathode surface. The result is most accurate for very low voltage, high pressure discharges. Comparison with experimental data shows quantitative agreement under these conditions.