Real time control of InxGa1−xN molecular beam epitaxy growth

The growth of GaN and InxGa1−xN on c-plane sapphire substrates was carried out by molecular beam epitaxy using NH3. In situ reflection high-energy electron diffraction (RHEED) was used to monitor the growth process. Oscillations of the specular beam intensity were observed during both GaN and InxGa1−xN deposition. This allows determining in real time the composition of InxGa1−xN alloys. The effects of the growth temperature and the Ga flux on the In incorporation rate were investigated. The critical thickness for InGaN islanding as a function of In mole fraction is also easily deduced from RHEED experiments.