Piezoelectric coefficient of InN thin films prepared by magnetron sputtering

Abstract

Indium nitride (InN) thin films have been deposited on Si(1 0 0) and Pt(1 1 1)/Ti/SiO2/Si(1 0 0) substrates by reactive r.f. magnetron sputtering. By using a plasma power of 25 W, nitrogen gas pressure of 5-7 mTorr and substrate temperature of 300-400 °C, InN films with (0 0 0 2) orientation were obtained. The relative permittivity and electrical resistivity of the InN film were calculated from the measured electrical impedance. The piezoelectric coefficient d33 of the InN film was measured by a heterodyne interferometer and found to be 3.12 ± 0.10 pm V-1.