Transient behaviour of CF₄rf plasmas after step changes of power source voltage

CF 4 radio-frequency (rf) plasmas are often driven in time-modulation modes to obtain higher etching performance. For dynamic and stable control of CF 4 plasmas, we investigated the transient behaviour of the plasmas after step up or down of the amplitude of the power source voltage V s ( t ). Using a one-dimensional fluid model, we simulated a CF 4 capacitively coupled plasma that transfers from a periodic steady state to another at 0.2 Torr in a 20 mm parallel-plate gap. In addition, we compared such plasma responses to the step down to 0 V at the phases at which V s ( t ) takes zero and peak values. Fundamental properties of transient CF 4 plasmas were discussed.