Deposition of SiO2 layers on 4H–SiC by photochemical vapor deposition

Abstract

SiO 2 insulating layers were deposited onto 4H–SiC substrates by a photochemical vapor deposition (photo-CVD) technique. It was found that the SiO2 growth rate increases linearly with total SiH4/O2 density for a fixed ratio of SiH4 and O2 partial pressure, due to the increasing densities of SiH2 and excited O atoms. It was also found that the interface state density, Dit, is equal to 3.27×1012, 3.16×1012, and 5.66×1011 cm−2 eV−1 for photo-CVD SiO2 layers prepared at 150, 300, and 500 °C, respectively. Furthermore, it was found that the leakage current was only 4.15×10−8 A/cm2 with an applied field of 4 MV/cm for the 500 °C photo-CVD grown Al/SiO2/4H–SiC metal–insulator–semiconductor capacitor.