GROWTH OF ZNO FILMS ON GAAS SUBSTRATES WITH A SIO2 BUFFER LAYER BY RF PLANAR MAGNETRON SPUTTERING FOR SURFACE-ACOUSTIC-WAVE APPLICATIONS

ZnO films were grown on GaAs substrates with or without SiO2 buffer layers by RF planar magnetron sputtering. The as-deposited ZnO films were characterized, using X-ray diffraction (XRD) and X-ray rocking curve, scanning electron microscopy (SEM) and reflection high-energy electron diffraction (RHEED). The SiO2 buffer layer is beneficial to the promotion of the ZnO film quality. The refractive indices of ZnO films obtained from m-line spectroscopy were 1.990 +/- 0.002 and 2.004 +/- 0.002, and are close to those of the ZnO single crystal. Surface acoustic wave (SAW) properties were also measured for SAW propagating along the [011] direction on (100) GaAs substrate.