X-ray photoelectron study in the initial stage of oxynitridation process by excited nitrogen and oxygen

In recent years, silicon oxynitride films have drawn attention as high-quality dielectrics, with decreasing the feature size in the integrated circuits. In this study, we try direct oxynitridation of silicon by remote-plasma-excited nitrogen and oxygen gaseous mixtures at the temperatures between 6008C and 8008C. We investigate the initial growth and bonding structures in the oxynitride films by in-situ X-ray photoelectron spectroscopy XPS.measurements. With the oxynitridation time, the surface concentration of nitrogen gradually increases, but that of oxygen shows nearly-saturation-behavior after rapid increase in the just initial stage. We found the two peaks derived from both N–Si2and N–Si3bonds in the photoelectron spectra of N 1s core levels in the initial stage. With the oxynitridation time, the N–Si3 bonds increase gradually and dominate the nitride bonds in the grown films. q1998 Elsevier Science B.V. All rights reserved