ON THE EPITAXY OF ALUMINUM NITRIDE ON SILICON SUBSTRATES IN A CHLORIDE-HYDRIDE PROCESS

The technological conditions under which the silicon surface interacts with vapor-phase reactants present in a chloride-hydride system for t he 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 s ystem is hindered by the interaction of the silicon with NH3 in the pr esence of HCl at T greater than or equal to 800 degrees C, with the fo rmation of an amorphous layer of Si3N4. To obtain a high-quality textu re it is important that prior to deposition of the AlN layers the sili con substrates be held in an NH3 atmosphere in order to form a dense l ayer of Si3N4. Single-crystal growth of AlN can be achieved in a chlor ide-hydride system of chemical deposition from the vapor phase at a re duced pressure, since the deposition temperature is then substantially lower (down to 550 degrees C) and the chemical interaction with the s ubstrate is hindered. (C) 1998 American institute of Physics. [S1063-7 850(98)02510-5].