Kinetics of the formation of titanium oxynitride and nitride under the action of VUV, studied by means of ellipsometry

Preparation of thin nanolayers (approximately 10 nm) with the required stoichiometry and minimal grain size is important for the development of nanostructures. The kinetics of the formation of titanium nitride and titanium oxynitride layers through nitridation of the titanium matrix was investigated in the present work. It was shown that the UV radiation causes an increase in nitridation rate, depending on radiation energy, within the studied range 4 to 21 eV. The investigation was carried out with the help of ellipsometry and independent methods: atomic force microscopy, electron microscopy, and X-ray photoelectron spectroscopy. The mechanism of titanium interaction with nitrogen resulting in the formation of nitride and oxynitride layers at the Si/Ti and SiO2/Ti interfaces was investigated, the role of the UV radiation in solid-state reactions was revealed, and the mechanism of the process was proposed on the basis of the experimental data and results of quantum chemical simulation. The use of UV radiation allowed us to obtain the layers at low temperatures (0-5 degrees C) and to achieve a short reaction time due to an increase in reaction rate. The resulting layers have good masking properties (minimal density of pores and defects, high smoothness of the surface). This allows one to use these layers for chemical and electronic passivation and stabilization of the surface of semiconductor nano-objects (quantum dots, quantum wires, nanowhiskers etc.) for electronic and photon nanodevices.