Transmission electron microscopy of the AlN–SiC interface

Abstract
The AlN–SiC interface has been studied using high-resolution transmission electron microscopy. Cross-section lattice images of the AlN–Sic interface have been analysed to establish the connection between image contrast and the atomic positions in the lattice. Assuming atomically abrupt and planar AlN–SiC interfaces, four possible atomic bonding configurations are taken into account for Sic substrates with the (0001)Si orientation. Image simulations of these four interface models are compared with the experimental images. Considering variations at the interface of the image contrast, the basal-plane distance and the projected charge density, it is shown that the C–Al and Si–N bonds are in agreement with the experimental images and are not distinguishable under our experimental conditions. The other two possibilities, involving C–N and Si–Al bonds, are not consistent with our observations.