The effect of an AlN buffer layer on the epitaxial growth of InN by molecul
ar-beam epitaxy (MBE) is studied. Using an AlN buffer layer can significant
ly improve the structural and electrical properties of InN. With increasing
thickness of the AlN buffer layer, the Hall mobility of InN will monotonic
ally increase while the electron carrier concentration decreases. The surfa
ce morphology of the film also improves. A Hall mobility of more than 800 c
m(2)/V s with a carrier concentration of 2-3 x 10(18) cm(-3) at room temper
ature can be routinely obtained on similar to0.1 mum InN film. More importa
ntly, it is found that under optimum growth conditions, by using an AlN buf
fer layer, InN films with comparable quality can be achieved by the convent
ional MBE technique compared to InN grown by migration-enhanced epitaxy. In
creasing InN thickness also increases Hall mobility. (C) 2001 American Inst
itute of Physics.