Design of Experiments for the Study of High-Power Pulsed Magnetron Sputtering

The purpose of this study was to conduct an experimental study of gas discharge during high-power pulsed magnetron sputtering of a metal target using a formal experimental design technique (active experiment). The method was applied to sputtering from a predominantly copper target in argon. Discharge voltage was the primary dependent variable; the independent variables were argon pressure, discharge current, pulse duration, and pulse repetition rate. Experiments were carried out on a balanced cylindrical magnetron over a narrow factor range. A first-order polynomial model was found to describe the variable relationships; its adequacy was confirmed by statistical analysis. Using the model, the effect of each factor on pulse power and pulse energy was quantified while holding other factors constant. Pulse fill factor (duty cycle) was introduced as an additional factor. Results from analogous experiments using a titanium target are reported for comparative evaluation.