Study of high temperature piezoelectric scandium aluminum nitride thin films

AlN has weak piezoelectric property (piezoelectric coefficient d33=5.5pCN-1) and a high Curie temperature (>1150°C). By Sc-doping in AlN thin films, it is possible to synthesize ScxAl1-xN alloy with high piezoelectric coefficient and high temperature stability. In this study, c-axis oriented AlN thin films have been successfully grown on Si (100) substrates by DC magnetron reactive sputtering method. First-principles calculations are also performed to investigate the structure of ScxAl1-xN.