The growth of AlN thin films on Si(111) substrate by plasma-assisted molecular beam epitaxy

GaN-based materials received great deal of attention because of the potential applications for optoelectronic devices operating in the whole visible spectral range and in electronic devices such as high temperature, high power, and high frequency transistor. The III-nitrides form a continuous alloy system with direct band gap ranging from 6.2 eV (AlN) to 0.7 eV (InN) with 3.4 eV for GaN. Consequently, the growth and physics of GaN-based materials have attracted tremendous scientific attention. This article reports the use of plasma-assisted molecular beam epitaxy ( MBE) to grow AlN on ( 111) Si substrate at 850 C under UHV conditions for 15, 30, and 45 minutes. The films were characterized by high-resolution x-ray diffraction (HR-XRD) and micro-Raman spectroscopy. XRD phase analysis of ( 0002) plane of GaN exhibits two intense and sharp peaks, namely Si(111) and AlN( 0002) diffraction peaks, at 28.4 and 36.1 respectively. Micro-Raman results show that all the allowed Raman modes of AlN and Si are visible.