Effect of substrate temperature on optical properties of EB-PVD-deposited silicon oxynitride thin films

Abstract

Electron Beam Physical Vapor Deposited (EB-PVD) silicon oxynitride (SiOxNy) films of various compositions between SiO2 and Si3N4 were grown by changing the substrate temperature and deposition time The SiOxNy films were deposited at various temperatures ranging from 100°C to 400°C on single crystal wafer ( single side polish)and soda lime glass substrates. Films were characterized by using XPS, EDS, Photoluminescence, UV-Visible spectroscopy and Ellipsometry. The ellipsometric measurements shows that the values of refractive indices , n and k are in the range of 1.60 to 1.98 and 0.03 to 0.08 respectively. The reflectivity of 1.64% was observed for the SiOxNy films deposited at T=350°C ant t=1.5 min. The XPS and EDS analysis shows the incorporation of nitrogen in the films increases with increase in substrate temperature and deposition time. The incorporation of nitrogen in the films is further confirmed by photoluminescence spectra. The photoluminescence spectroscopy measurements were done at room temperature. The energy of the PL peak for 2.54eV (~490 nm) excitation is 2.30 eV (~560 nm). From the above results we feel that the EBPVD deposited SiOxNy films has tremendous potential in antireflective applications.