A study on the reactive sputtering process with plasma chemistry

In this study, a completed mathematical model based upon earlier studies by Berg and Pekker for reactive sputtering is established to generically include the chemical reactions in plasma. For the purpose of parameter analysis, several representative chemical reactions were chosen and the governing equations were expressed in a non-dimensional form. Several non-dimensional parameters were also defined in line with their physical significances. Results show that the stability is characterized by the well-known hysteresis loop in the steady state solutions. Through parameter analysis, we found when the chemical reaction on substrate is moderate, a higher sputter yield of the compound leads to a more stable steady state at lower inflow rates. The presence of various gases in the plasma has different effects on the hysteresis. Results indicate the increase of particles such as the ion of atomic reactive gas and electrons could reduce the hysteresis and hence stabilize the process.