INVESTIGATION OF BURIED ALN LAYERS FORMED BY NITROGEN IMPLANTATION INTO AL

The composition and microstructure of buried layers of AlN formed by h igh energy N+ ion implantation into polycrystalline Al have been deter mined. Both bulk and evaporated thin films of Al have been implanted w ith 100 and 200 keV N+ ions to doses of up to 1.8 x 10(18)/cm2. The la yers have been characterised using SIMS, XTEM, X-ray diffraction, FTIR , RBS and in terms of their microhardness. It is found that, for doses greater than the critical dose, buried, polycrystalline AlN layers ar e formed with preferred (100) or (002) orientations, which are sample specific. With increasing dose the nitrogen concentration saturates at the value for stoichiometric AlN although the synthesised compound is found to be rich in oxygen.