Aluminum nitride films on different orientations of sapphire and silicon

Abstract
The details of epitaxial growth and microstrictural characteristics of AlN films grown on sapphire (0001), (101̄2) and Si (100), (111) substrates were investigated using plan‐view and cross‐sectional high‐resolution transmission electron microscopy and x‐ray diffraction techniques. The films were grown by metalorganic chemical vapor deposition using TMA1+NH3+N2 gas mixtures. Different degrees of epitaxy were observed for the films grown on α‐Al2O3 and Si substrates in different orientations. The epitaxial relationship for (0001) sapphire was found to be (0001)AlN∥(0001)sap with in‐plane orientation relationship of [011̄0]AlN∥[1̄21̄0]sap. This is equivalent to a 30° rotation in the basal (0001) plane. For (101̄2) sapphire substrates, the epitaxial relationship was determined to be (112̄0)AlN∥(101̄2)sap with the in‐plane alignment of [0001]AlN∥[1̄011]sap. The <named-content xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"...