STRUCTURE AND FORMATION MECHANISMS OF GERMANIUM NITRIDE-OXYNITRIDE FILMS ON SINGLE CRYSTAL GERMANIUM.
Abstract
The formation of passivating insulators on semiconductor surfaces is an integral part of the current technology used in the fabrication of planar devices. Therefore, the formation of native insulators on alternative semiconductors such as germanium is of considerable interest. Stable oxide films were thermally grown on single crystal germanium at relatively low temperatures via high pressure oxidation. These very dense and uniform layers were subsequently nitrided in flowing ammonia at 450 degree C-700 degree C. The resulting nitrided films exhibited several different growth morphologies that were sensitive to gas flow rate, temperature and nitriding gas composition. Based on a detailed microstructural analysis, a mechanism for the nitridation of germanium oxide films is proposed.