The gate dielectrics for silicon carbide based MOS devices are still crucial for their performance and reliability. Conventional thermal oxides have a poor interface quality and a low dielectric constant. To mitigate the issues brought about by conventional thermal oxidation, Al(ON) based on atomic layer deposition (ALD) technique is proposed and studied in terms of interface state density and dielectric strength/reliability. To make comparison, the results of AlN and Al2O3 grown using the same ALD technique, are included as well. It is shown that by incorporating of nitrogen/AlN, Al(ON) can reduce interface state density and border trap density. In addition, its dielectric strength/reliability in terms of time-zero-dielectric breakdown (TZDB) also improves.

The effect on amplitude of EXAFS from harmonic caused by high order diffraction of crystal monochromator is discussed. The general expression and calculated results are presented. It is shown that the harmornic decreases the amplitude of EXAFS and the amount of decrease is related to such factors as intensity ratio of harmonic to fundamental, thickness and absorption coefficient of specimen. K edge EXAFS spectra with and without harmonic for different thickness copper foils have been measured respectively, and the distortion of single shell EXAFS amplitudes have been extracted. The measured results are consistent with calculated ones. Consequently, a method to correct the harmonic effect on EXAFS amplitude is proposed.

An analysis method of the extended x-ray absorption fine structure (EXAFS) for mixed-coordination systems (MCS) is provided to determine structure parameters of the same type of atoms located at different coordination sites and proportion of them. It's demonstrated that if the effects of different sites on EXAFS amplitudes are ignored, the coordination numbers gotten from EXAFS analyzing must be wrong mostly. The method has been well tested by analyzing a known structure Gd3Ga5O12 (GGG) crystal in which the Ga atoms have two different coordination sites. Li2O-ZnO-GeO2 glass system is also analyzed by means of the EXAFS method for MCS. Two different coordination sites for Ge atoms in the glasses. are found and the occupancies of them and the structure parameters are determined.

A method of EXAFS analysis to determine phase content and local structure surrounding same type atoms in different phase of a mixed phases system is proposed. A general expression of χ(κ) function for a two phases system is presented. To verify the method, the EXAFS of some specimens were measured and analyzed. The results agreed well with expected ones.