Optical and electrical properties of LPCVD silicon oxynitride films on silicon

The optical and electrical properties of SiOxNy films prepared by low-press ure (5.3 mbar) chemical vapour deposition (LPCVD) at 860 degreesC were stud ied by means of spectroscopic ellipsometry and analysis of 1 MHz capacitanc e-voltage characteristics. Correlation of the refractive index and dielectr ic permittivity of LPCVD films and their composition with the increase of n itrous oxide content in the deposition ambient is established. The density of the effective dielectric charges and interface traps reduces with nitrid ation of the films. The observed low densities of the interface traps are a ttributed to the nitrogen incorporation at the SiOxNy/Si interface which le ads to suppression of interface trap generation. (C) 2001 Elsevier Science Ltd. All rights reserved.