In this work, we investigate the interface formation and electrical properties between TiNx and SiO2 for application of a gate electrode as a function of annealing temperature, TA. Auger electron spectroscopy (AES) and four-point probe measurement were performed to measure the chemical composition and sheet resistance, R-s, respectively, of TiNx/SiO2 films. Also, interface formation of TiNx/SiO2 films as a function of annealing temperature was investigated by x-ray photoemission spectroscopy (XPS) depth profiling. X-ray diffraction spectra showed an increase in the crystallinity of TiNx above T-A = 600 degreesC. AES and XPS data show that thermal annealing of the sample with TiNx deposited at an Ar/N-2 gas flow ratio of 6/1 (Q(Ar)/Q(N2) = 6/1) above 600 degreesC increases the oxidation reaction of TiNx layers, resulting in the formation of TiO2 phases. The R-s values increased at elevated annealing temperatures above 600 degreesC for TiNx, deposited with Q(Ar)/Q(N2) = 6/1, but the R-s values of TiNx deposited at an Ar/N-2 gas flow ratio of 6:3 continuously decreased up to T-A = 800 degreesC.