First-principles study of β-AlN thin films on β-SiC(001)

We have investigated the initial stages of formation of cubic AlN films on SiC(001) by studying the energetics of possible structures. We have considered 1X1 and p(4X1) surface reconstructions for the films, and we have allowed for different interface arrangements including atomic mixing. The results of our first-principles calculations reveal that, in N-rich conditions, no two-dimensional film structure is stable. However, in Al-rich conditions, it is possible to stabilize a thick wetting layer of cubic AlN provided the proper interface mixing is achieved. The most stable AlN film exhibits a p(4X1) surface reconstruction. (C) 1999 American Institute of Physics. [S0003-6951(99)03915-7].