High aluminium content and high growth rates of AlGaN in a close-coupled showerhead MOVPE reactor

The growth rates and aluminium contents of AlxGa1−xN layers grown in a close-coupled showerhead reactor were investigated as a function of growth pressure and chamber height during metal-organic vapour phase epitaxy. The data show strong non-linear dependencies due to nanoparticle formation in the gas-phase. Good agreement between the experimental data and modeling results is obtained when the contribution of both Ga- and Al-containing species to the gas-phase particle formation is considered.