Effect of a Gas Pressure on the Growth Rate of AlN Layer

Abstract

The dependence of the layer growth rate on a gas (argon, nitrogen) pressure inside the reactor has been examined in order to analyze the conditions of growth of AlN thick layers and bulk crystals by the sublimation sandwich-method. It is shown that the layer growth rate steadily increases as the pressure in the reactor decreases in a wide pressure interval 1–0.02 bar. This suggests that a key role in the layer growth kinetics is played by the source-to-substrate transfer of the components (Al, N), rather than the adsorption - desorption processes on the source and substrate surface. In addition the growth rate in argon atmosphere is much higher than in nitrogen one for the high pressures and is practically the same for the lowest (0.05 – 0.02 bar).