Nucleation of AlN on the (7 ×7) reconstructed silicon (111) surface

Abstract

The (7×7) reconstructed (111) surface of silicon is found to be an excellent surface for the nucleation of epitaxial aluminum nitride, despite the +23.4% misfit in the AlN/Si system. AlN nucleated above the (7×7) to (1×1) transition temperature (830°C) is found to contain 30° misoriented grains, while films nucleated below the transition temperature are single orientation. Optimized aluminum nitride films grown on (7×7) silicon surfaces make excellent substrates for GaN heteroepitaxy.