Interface Properties of the Two Step Oxide Layers by UV Light Excited Ozone Silicon Oxidation and Chemical Vapor Deposition (CVD)-SiO2 Film

SiO2 film was made on Si(100) by two-step film growth process at 100°C to improve the interface properties. The first part of the process is the direct Si oxidation using UV-excited ozone (O(1D)), which is generated by the UV irradiation to high concentrated (>90%) ozone gas. In the second part, O(1D) and Hexamethyldisilazane chemical vopor deposition (CVD)(O(1D)-CVD) process is used. The SiO2 film thickness of the direct Si oxidation for 10 min. in the two-step SiO2 film was estimated to be about 3.2 nm from the etching rate in change a buffered HF solution. Interface trap density Dit of the two-step SiO2 film with direct Si oxidation of 10 min. is almost equal to that of Si direct oxidation film alone. This result indicates that two-step oxidation process can be applied for the practical fabrication.