Passivation of Crystalline Silicon Wafers by Ultrathin Oxide Layers: Comparison of Wet-chemical, Plasma and Thermal Oxidation Techniques

摘要

Ultrathin oxide layers on crystalline silicon (c-Si) were prepared by different wet-chemical, plasmaand thermal oxidation techniques. The resulting electronic and chemical SiO₂/Si interface properties were analyzed, compared and evaluated by combined x-ray photoemission (XPS) and surface photovoltage (SPV) measurements. Depending on the oxidation technique, chemically abrupt SiO₂/Si interfaces (suboxide amounts <; 5 %) with low densities of interface states (<; 1×10^{12 cm-2eV-1) were obtained on c-Si either at low temperatures as well as at short oxidation times and in wet-chemical environment, resulting in each case in excellent interface passivation. It is shown, that chemically abrupt SiO₂/Si interfaces are able to generate low interface defect states densities.}