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/SiO 2 /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 d 33 of the InN film was measured by a heterodyne interferometer and found to be 3.12±0.10 pm V −1 .