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 integrat ed circuits. In this study, we try direct oxynitridation of silicon by remote-plasma-excited nitrogen and oxygen gaseous mixtures at the tem peratures between 600 degrees C and 800 degrees C. We investigate the initial growth and bonding structures in the oxynitride films by in-si tu X-ray photoelectron spectroscopy (XPS) measurements. With the oxyni tridation time, the surface concentration of nitrogen gradually increa ses, but that of oxygen shows nearly-saturation-behavior after rapid i ncrease in the just initial stage. We found the two peaks derived from both N-Si-2 and N-Si-3 bonds in the photoelectron spectra of N 1s cor e levels in the initial stage. With the oxynitridation time, the N-Si- 3 bonds increase gradually and dominate the nitride bonds in the grown films. (C) 1998 Elsevier Science B.V. All rights reserved.