Effect of frequency and pulse-on time of high power impulse magnetron sputtering on deposition rate and morphology of titanium nitride using response surface methodology

Abstract

Abstract Titanium nitride thin films were deposited on silicon by high power impulse magnetron sputtering (HiPIMS) method at different frequencies (162−637 Hz) and pulse-on time (60−322 μs). Response surface methodology (RSM) was employed to study the simultaneous effect of frequency and pulse-on time on the current waveforms and the crystallographic orientation, microstructure, and in particular, the deposition rate of titanium nitride at constant time and average power equal to 250 W. The crystallographic structure and morphology of deposited films were analyzed using XRD and FESEM, respectively. It is found that the deposition rate of HiPIMS samples is tremendously dependent on pulse-on time and frequency of pulses where the deposition rate changes from 4.5 to 14.5 nm/min. The regression equations and analyses of variance (ANOVA) reveal that the maximum deposition rate (equal to (17±0.8) nm/min) occurs when the frequency is 537 Hz and pulse-on time is 212 μs. The experimental measurement of the deposition rate under this condition gives rise to the deposition rate of 16.7 nm/min that is in good agreement with the predicted value.