Cathode sheath processes in a non-sputtering magnetron discharge. (December 2018) - Kaziev, Andrey V.
Abstract: The properties of cathode sheath in a non-sputtering magnetron discharge are discussed involving the theoretical assumptions based on the classical glow discharge description, and magnetron specific effects. It is shown that in a wide range of experimental conditions (gas pressure p from 1 to 100 Pa, discharge current I d from 10 to 1500 A), the trends for principal plasma parameters (electron density n and temperature T e ) remain the same. Nevertheless, there is crucial difference in dominant supply of electrons between low pressure and elevated pressure non-sputtering magnetron regimes. Both secondary electron emission at low pressures and thermal ionization at high pressures result in sufficiently high electron source for sustaining dense non-sputtering magnetron plasmas at characteristically low voltage V d ∼ 80–120 V. Highlights: In the cathode sheath of a non-sputtering magnetron discharge the electrons gain energies only for 1–2 ionizing collisions. Both low- and high-pressure NSMD regimes offer dense uniformly distributed plasmas with low ion energies. Only materials with high ion induced electron emission yield are capable of sustaining NSMD at low pressures.