AlN thin films grown on epitaxial 3C–SiC (100) for piezoelectric resonant devices

Abstract

Highly c-axis oriented heteroepitaxial aluminum nitride (AlN) films were grown on epitaxial cubic silicon carbide (3C–SiC) layers on Si (100) substrates using alternating current reactive magnetron sputtering at temperatures between approximately 300–450 °C. The AlN films were characterized by x-ray diffraction, scanning electron microscope, and transmission electron microscopy. A two-port surface acoustic wave device was fabricated on the AlN/3C–SiC/Si composite structure, and an expected Rayleigh mode exhibited a high acoustic velocity of 5200 m/s. The results demonstrate the potential of utilizing AlN films on epitaxial 3C–SiC layers to create piezoelectric resonant devices.