High Rate Deposition of Thick Piezoelectric ZnO and AlN Films Using a New Magnetron Sputtering Technique

Abstract

ZnO and AlN films were prepared on glass substrates with a new reactive magnetron sputtering technique using a metal target. Highly oriented ZnO films (c-axis orientation) were fabricated on the glass substrates. Resistivities of the films were 106–109 Ω cm for ZnO and 109–1011 Ω cm for AlN. An electromechanical coupling constant of thick ZnO films (∼30 µm) was obtained by measuring a frequency response of transducer impedance near the fundamental resonance frequency of the interdigital electrode. For AlN, the c-axis orientation from substrate normal to parallel can be controlled by adding H2 gas to N2 gas.