Dependence of the Flatband Voltage of Si-MOS on Distribution of Cesium in SiO₂ Comparison of Two Implantation Methods

Correlation between measured shifts in the flatband voltage, ΔVFB, of Si-MOS structure and physical distribution of cesium ions in SiO2 as measured by secondary ion mass spectrometry has been investigated. Direct implantation of Cs into SiO2 and into Si with the subsequent oxide growth results in different profiles that depend on thermal processing. Corresponding negative AVFB are increasing with the amount of Cs in SiO2 in the first case and in the latter case depend also on the height of cesium peak at SiO2/Si interface. The change in the interface state density due to Cs is small. © 1986, The Electrochemical Society, Inc. All rights reserved.