REACTIVE MOLECULAR-BEAM EPITAXY OF ALUMINUM NITRIDE

Single-crystal films of AlN have been fabricated on sapphire and silicon substrates by reactive molecular beam epitaxy (MBE) at 1000 degree - 1200 degree C. The crystal quality of the films was examined by the reflection high-energy electron diffraction technique and the measurement of cathodoluminescence. The results indicate that the epitaxial AlN films prepared by reactive MBE have good quality as compared with bulk single crystal. Nonlinear optical coefficients and the electromechanical coupling constant of surface acoustic waves were also measured. It was found that the AlN films have unique characteristics and are promising for nonlinear optical and surface acoustic wave devices.