Microstructure of AlN on Si (111) grown by plasma-assisted molecular beam epitaxy

Abstract

We have grown monocrystalline AlN on Si (111) substrates over the temperature range 550–900 °C using electron cyclotron resonance plasma assisted molecular beam epitaxy. The best (0002) peak omega rocking curve full width at half-maximum value obtained was 26 min for a film deposited at 900 °C. All films nominally displayed the AlN[0001]∥Si[111] orientation. The exact angle between AlN[0001] and Si[111] decreased from 2.1° to 1.1° and the (0002) peak widths improved with increasing substrate temperature. Mosaic-type disorder was shown by high resolution x-ray diffraction to be the dominant cause of the ω rocking curve peak full widths.