Influence of growth temperature and scandium concentration on piezoelectric response of scandium aluminum nitride alloy thin films

The authors have investigated the influence of growth temperature and scandium concentration on the piezoelectric response of scandium aluminum nitride (ScxAl1−xN) films prepared by dual reactive cosputtering. The piezoelectric response strongly depends on the growth temperature and scandium concentration. The piezoelectric response of the films prepared at 400 °C gradually increases with increasing scandium concentration. On the other hand, the piezoelectric response of the films prepared at 580 °C drastically decreases and increases in the scandium concentration from 30% to 40%. We think that the drastic change of the piezoelectric response is due to the disordered grain growth.