Growth of high-quality AlN with low pit density on SiC substrates

Abstract

We investigated the optimum growth condition and initial growth process of AlN on 6H-SiC(0 0 0 1) substrates prepared by H 2 etching in the plasma-assisted molecular beam epitaxy (MBE). In X-ray rocking curve measurements, a small full-width at half-maximum of about 50 arcsec was obtained for a 150 nm thick AlN layer. The AlN layers have contained a lot of pits over a grown surface. Pit densities were markedly decreased by reducing the amount of residual impurities (O, OH and H 2O) in an MBE chamber. A very low pit density of 10 4–10 5 cm −2 was realized.