Effect of H2 on an argon discharge for planar magnetron sputtering

Publisher Website
Google Scholar
Abstract
A planar magnetron has been operated in Ar/H2 mixtures to determine whether H2 has a significant effect on the sputtering characteristics as it does in diode systems. An Al target was sputtered in dc and rf discharges at powers up to 2.3 kW and H2/Ar ratios from 0 to 1.1. At a fixed argon flow, the total pressure increased from 0.6 to 1.3 Pa as the H2 flow rate increased to 4.4 cc/min. For the same rf power, the target self‐bias voltage was independent of the H2 partial pressure but the dc impedance did increase with H2 flow; to maintain a current of 3A, the dc voltage had to be increased from 370 to 450 V as the H2 flow rate increased to 5.0 cc/min. The deposition rate of Al was measured by a quartz microbalance as a function of power and no significant decrease in rate was evident up to the highest H2/Ar ratio. In diode sputtering, a ratio of 0.01 causes a 10% decrease in rate. A set of reactions for the formation and removal of Ar+, H+, and ArH+ have been used to model the relative ion concentrations. A correlation between the model and experimental results suggests that the H+ concentration is significant in the diode case and causes a decrease in sputtering rate but it is negligibly small in the magnetron discharge due to the much higher electron density and the electron trapping.

This publication has 0 references indexed in Scilit: