Molecular Beam Epitaxial Growth of AlN Thin Films on Si through Exploiting Low Al Adatom Migration and the Nitrogen-Rich Environment on a Nanowire Template
Xue Yin, Qihua Zhang, Songrui Zhao
Abstract
In this work, we demonstrate an aluminum nitride (AlN) thin film on Si through exploiting the low Al adatom migration and the nitrogen (N)-rich environment on a nanowire template by molecular beam epitaxy. The AlN thin film is relatively smooth, and the X-ray diffraction experiments further suggest that the film is nearly strain free. In addition, the observation of 3 × 3 reconstruction from the reflection high-energy electron diffraction suggests that the AlN film is N-polar, which is further confirmed by chemical etching experiments. We further show that, using such an AlN thin film as a buffer layer, room-temperature ultraviolet-emitting aluminum gallium nitride (AlGaN) epilayers at various wavelengths can be obtained on Si.