On the epitaxy of aluminum nitride on silicon substrates in a chloride-hydride process
Abstract
The technological conditions under which the silicon surface interacts with vapor-phase reactants present in a chloride-hydride system for the epitaxial growth of aluminum nitride are determined. The method of electron channeling patterns is used to show that the growth of single-crystal layers of AlN on silicon substrates in the chloride-hydride system is hindered by the interaction of the silicon with NH3 in the presence of HCl at T⩽800°C, with the formation of an amorphous layer of Si3N4. To obtain a high-quality texture it is important that prior to deposition of the AlN layers the silicon substrates be held in an NH3 atmosphere in order to form a dense layer of Si3N4. Single-crystal growth of AlN can be achieved in a chloride-hydride system of chemical deposition from the vapor phase at a reduced pressure, since the deposition temperature is then substantially lower (down to 550°C) and the chemical interaction with the substrate is hindered.