The influence of N 2 partial pressure and substrate bias on electron density and temperature in a dc sputtering diode

Abstract

Single probes and grid probes were used to study the density and the energy of the slow and secondary electron groups in the negative glow plasma of a dc diode sputtering system. The influence of a negatively biased electrode and of a reactive gas partial pressure were specially examined. When the bias voltage is varied from 0 to −200 V the densities of the slow and secondary electron groups clearly increased but their energies suffer little change. The electron density value can increase threefold. Introduction of a reactive gas (N 2) into the gas discharge (Ar) leads to a rapid decrease in the density and the energy of the slow electron group when a critical pressure p c is reached. The secondary group density decreases regularly when the nitrogen pressure increases but the energy remains constant.