High Quality ZnO Thin Films on InP Substrates Prepared by Radio Frequency Magnetron Sputtering. II. Surface Acoustic Wave Device Fabrication

ZnO/InP based surface acoustic wave (SAW) devices were successfully fabricated. High quality ZnO films were first deposited onto InP substrates by radio frequency magnetron sputtering, and the SAW devices were fabricated on top of ZnO. It was found that the characteristics of the SAW devices depend strongly on the quality of the ZnO thin films and thus on the ZnO deposition parameters. To obtain a low loss SW device, one must have a high quality ZnO thin film. With a type I pattern, we found that the minimum insertion loss is 34 dB. Inserting counter electrodes can further reduce the insertion loss to 23 dB.