CHARACTERIZATIONS OF OXIDE GROWN BY N2O

The constitution of N2O oxide has been investigated by using Auger analyses, ellipsometry measurement, and Fourier transform infrared (FTIR) spectroscopy in this paper. We found a nitrogen-rich layer formed at the interface of SiO2/Si by Auger analyses. From the results of ellipsometry, we found the thinner the N2O oxide, the larger the refractive index. A two-layer model construction of N2O oxide was proposed for modeling the interfacial layer. We found that this layer thickness is 14 to 20 angstrom when the refractive index was set to 1.77. FTIR analyses show that some of the Si-O bonds were replaced by Si-N bonds. This is the reason that N2O oxide has better electrical properties and a lower growth rate than those of the conventional dry 02 oxide.