Interface properties of the Si(100)-SiO₂ system formed by rapid thermal oxidation

In this work, the properties of the Si(100)-SiO₂ interface are examined directly following wet and dry rapid thermal oxidation (RTO) at 1000-1100°C. The high frequency and quasi-static CV response of the Si(100)-SiO₂ system are measured using a mercury probe method. The analysis indicates a high interface state density across the band gap for dry oxidation, with a characteristic peak in the range 0.8-0.9 eV above the valence band edge. These interface state profiles are compared to polysilicon/oxide/Si(100) structures, measured after rapid thermal annealing at 1050°C (where the gate oxide is grown by conventional furnace oxidation). The results show a striking similarity, pointing to a common origin for the interfacial defects. Steam-assisted RTO samples do not reveal these peaks, and the reasons for this are presented. The significance of these new results to thin oxide growth and optimisation by RTO are discussed.