TIME-DEPENDENT SIMULATION MODELING OF REACTIVE SPUTTERING

A time-dependent simulation model of reactive sputtering is proposed. The model deals with time-dependent poisoning of the target surface and hysteresis phenomena. The model is based on the calculation of the time-dependent change in gettering pumping speed and target poisoning speed, yielding the time-dependent change in target coverage and reactive gas partial pressure. By calculating the equilibrium values of the time-dependent change over a range of reactive gas flow rates, hysteresis effects of target coverage and reactive gas partial pressure are investigated as a function of the gas flow rate. The hysteresis results obtained suggest that with the time-dependent model it is possible to evaluate the effect of pumping speed on the transition points and width of hysteresis curves. As compared with experimentally investigated results it is found that the model explains mechanisms of reactive sputtering qualitively.