2008 Volume 51 Issue 3 Pages 228-231
We have oxidized Si wafer at lower than 200°C using an electronically excited oxygen atom that is generated by the irradiation of UV light to low pressure highly concentrated ozone gas. We used high-pressure mercury lamp, as the light source because it has a strong emission between 210 nm and 300 nm by which ozone is effectively absorbed and photo-excited. SiO2 film formation with its thickness fluctuation of less than 0.2 nm within light-irradiated area has been easily achieved as long as the intensity of the light irradiated to low-pressure ozone is uniform within 10 percent. The SiO2 film thickness is 3.3-4.1 nm at 200°C for 10 min on the 8″Si(100) wafer. By the sample rotation during oxidation process, we could oxidize the SiO2 film homogeneously on the 8″ wafer.
This film can be applied to a buffer layer between deposited film and poly-Si substrate of the gate dielectric film of the low temperature poly-Si thin film transistor.
