Electrical characteristics of high-quality sub-25-/spl Aring/ oxides grown by ultraviolet ozone exposure at low temperature

We have developed a method for controllably and reproducibly growing self-limiting ultrathin oxides with excellent electrical properties in the range /spl sim/10-25 /spl Aring/ thick at temperatures ranging from 25 to 600/spl deg/C, respectively, using an ultraviolet ozone (UVO/sub 3/) oxidation process. The self-limiting thickness depends primarily on the substrate temperature, allowing ultrathin oxide growth with precision and reproducibility using this UVO/sub 3/ process. Oxides grown by this method are comparable in electrical quality to thermal oxides, with similar leakage current densities and breakdown fields E/sub BD/>10 MV/cm. Current-voltage (I-V) analysis shows oxide thickness uniformity to within 1% from center to edge of a 4-in wafer. Capacitance-voltage (C-V) characterization of /spl sim/25 /spl Aring/ oxides shows excellent saturation behaviour, with low midgap interface trap densities and no hysteresis or dispersion.