Parameters and Stability Analysis of Reactive Sputtering

Based on Berg's model for reactive sputtering, several nondimensional parameters and ratios are first identified in line with their physical significance. These parameters and ratios are subsequently used to analyze the steady-state solutions of reactive sputtering in detail. Results show that, when the chemical reaction in the substrate is moderate, the lower sputter yield of a compound enhances the hysteresis loop at higher inflow rates. However, when the ratio of sputtering yield (compound/metal) is zero, there is no hysteresis transition because of the deposition of pure metal (single phase) on the substrate. Hysteresis is influenced by pumping speed and a stability criterion is established based on the segment of s curve with negative slope. From the criterion, two turning points for the hysteresis loop can be easily found either graphically or algebraically.