Low temperature and fast growth of one-directionally grown aluminum nitride film by atmospheric pressure halide CVD method

Abstract

Aluminum Nitride (AlN) shows high thermal conductivity, high electrical resistivity, and chemical stability and expected as a candidate for a substrate of Al_xGa_1−xN based thin films for LEDs. In the present study, we demonstrate low temperature (800°C) and fast growth (9.2 µm/h) of one-directionally grown AlN film by atmospheric pressure halide CVD method, in which AlN films grow under air pressure without any requirement of vacuum systems. For obtaining uniaxial AlN films, seeding layer prepared at the initial stage of the growth plays an important role. Growth mechanisms and effects of the seeding layer is discussed based upon optical and miscrostructural analyses.