GROWTH OF SINGLE-CRYSTAL GAN ON A SI SUBSTRATE USING OXIDIZED ALAS ASAN INTERMEDIATE LAYER

We demonstrate that single-crystal hexagonal GaN can be grown by metal -organic chemical vapor deposition on an aluminum oxide compound (AlOx ) layer utilized as an intermediate layer between GaN and a Si(1 1 1) substrate. The surface morphology of GaN grown on the AlOx/Si(1 1 1) s ubstrate is found to be very sensitive to both the GaN buffer-layer th ickness and the AlOx thickness. Contact mode atomic force microscopy ( C-AFM) observation indicates that the AlOx surface is composed of doma in-like features with varying surface heights. A possible clue for a m echanism by which single crystal GaN grows on AlOx is discussed by com paring the domain-like surface features observed by C-AFM. (C) 1998 El sevier Science B.V. All rights reserved.