Influence of process parameters on the growth of pure-phase anatase and rutile TiO2 thin films deposited by low temperature reactive magnetron sputtering

In this work is investigated the optimal conditions for deposition of pure-phase anatase and rutile thin films prepared at low temperatures (less than 150 degrees C) by reactive de magnetron sputtering onto well-cleaned p-type Si substrates. For this, the variation of deposition plasma parameters as substrate-to-target distance, total gas pressure, oxygen concentration, and substrate bias were studied and correlated with the characteristics of the deposited films. The XRD analysis indicates the formation of pure rutile phase when the substrate is biased at voltages between -200 and -300 V. Pure anatase phase is only attained when the total pressure is higher than 0.7 Pa. Moreover, it's noticeable a strong dependence of surface roughness with parameters studied.