Aluminum Nitride Crystal Growth by Halide Vapor Transport Epitaxy

Abstract

AbstractHalide vapor transport epitaxy (HVTE) is demonstrated for growth of AlN layers with thickness up to 50 μm at deposition rates up to 60 μm/h. The HVTE process uses an aluminum chloride amine adduct as the aluminum source of both aluminum and nitrogen. This new technique eliminates the main difficulties of the conventional hydride VPE growth, where aluminum oxidation and the strong reactivity of aluminum chloride with fused silica create the potential for oxygen contamination. This study shows the effect of temperature, gas flow velocities, and reactor pressure on the growth rate and layer quality. It is found that the growth rate and the layer quality strongly depend on the gas ratio. The species of carrier gas, the flow rates and partial pressures can be used as tools to optimize growth rate and to avoid any etching effects resulting from reverse chemical reactions. The crystalline layer quality as determined by x-ray rocking curve measurement shows FWHM of 300–900 and 500–1300 arc-sec for (002) and (102) planes, respectively.PACS: 81.05.Ea; 81.15.Kk; 68.55.Jk.