Room Temperature Photoluminescence and Raman Characterization of Interface Characteristics of SiN/SiO2/Si Prepared under Various Deposition Techniques and Conditions

Room temperature photoluminescence (RTPL) spectroscopy and Raman spectroscopy were examined as in-line monitoring techniques for characterizing the interface characteristics of ultra-thin (similar to 7.2 nm) stacked dielectric films (SiN/SiO2) on 300 mm Si wafers. To investigate the effect of the stacked dielectric films on electronic properties and lattice stress of Si beneath the films, RTPL and Raman signals were measured under various excitation wavelengths with different probing depths. Changes of interface characteristics (mainly, electronic properties and lattice stress of Si beneath the films) of the stacked dielectric films and the Si wafer were investigated using various specimens prepared by different deposition techniques and conditions. The overall interface characteristics of the SiN/SiO2/Si specimens was found to be very dependent on the SiN deposition technique and process conditions. As the stoichiometry of SiN films change from N-rich to Si-rich conditions, the RTPL signal becomes weaker, indicating the change of electronic properties at the SiN/SiO2/Si interface. Within-wafer and wafer-to-wafer variations of the SiN/SiO2/Si interface characteristics were successfully characterized by RTPL and Raman spectroscopy under various excitation wavelengths. Other characterization results such as film thickness from ellipsometry, film stress from wafer curvature and film composition from Auger electron spectroscopy (AES) were also discussed. (C) The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.