Surface morphologies of AlGaN films and AlGaN/GaN heterostructures on vicinal sapphire (0001) substrates grown by rf-MBE

摘要

Surface morphologies of AlGaN films and AlGaN/GaN heterostructures are investigated. It is found that the surface morphologies of AlGaN are greatly improved by using vicinal substrates. Well-defined steps cover the surfaces, and micro-cracks and pinholes disappear. It is expected that the reductions of micro-cracks and pinholes connect to the high performance of electronic device such as HEMT.