Silicon wafer cleaning processes and ozone oxide growth as studied by angle-resolved x-ray photoelectron spectroscopy (ARXPS) and ellipsometry

Knowledge of silicon oxide layer thickness and stoichiometry is essential for the integration of new dielectric materials. Among the various ways of obtaining ultrathin silicon oxides, chemically grown oxides are a promising choice. Different cleaning processes of silicon wafer for microelectronic integrated-circuit-scale application were investigated by XPS and ellipsometry. In this work, overlayer thicknesses were deduced from XPS intensity photoelectron lines and ellipsometric measurements. A comparison between these techniques was carried out. Chemical compositions of the overlayers were deduced from XPS measurements, and an ellipsometric calibration is proposed according to the relative oxygen atomic concentration. Copyright (C) 2002 John Wiley Sons, Ltd.