Properties of Gate-Quality SiO2 Films Prepared by Electron Cyclotron Resonance Chemical Vapour Deposition in an Ultrahigh Vacuum Processing System

ABSTRACTWe have prepared thin SiO2 layers on Si(100) wafers by electron cyclotron resonance chemical vapour deposition (ECR-CVD) in a multi-chamber ultra-high vacuum (UHV) processing system. The oxides were characterized in-situ by single wavelength ellipsometry (SWE) and x-ray photoelectron spectroscopy (XPS) and ex-situ by Fourier transform infra-red spectroscopy (FTIR), spectroscopic ellipsometry (SE) and capacitance-voltage (CV) electrical measurements. Films deposited at higher pressures, low powers and low silane flow rates had excellent physical and electrical properties. Films deposited at 400 °C had better physical properties than those of thermal oxides grown in dry oxygen at 700 °C. A 1 minute anneal at 950 °C reduced the fast interface state density from 1.2×1011 to 7×1010 eV−1cm−2