Study of sputtering process of alumina thin films

Thin film capacitors with alumina dielectrics were formed on glass substrates. The dielectrics was prepared by reactive magnetron sputtering under following conditions: the power of the RF generator was 70 W and 150 W, the pressure of argon was 1.5 and 2.5 Pa and the flow of oxygen was 10 and 20 ml/min. The time of sputtering was 20 min. Mathematical models of the sputtering process for the capacitance and the loss factor of the capacitors in dependence on the process parameters (power of the RF generator, argon pressure and oxygen flow) were found using the method of factorial experiments. It was found that the significance of the process parameters and their interactions on the capacitance of the capacitors is comparable whereas the power of the RF generator has the highest influence on the loss factor of the capacitors.