Interface defects of ultrathin rapid-thermal oxide on silicon

We have used capacitance-voltage and electron paramagnetic resonance to measure interface defects in ultrathin (30 Å) SiO2 prepared by rapid-thermal oxidation. We observe a very narrow interface state peak in the upper portion of the Si band gap, as well as both Pb0 and P b1 defects in the as-oxidized film. Forming-gas annealing removes the interface state and most of the Pb centers. However, from the energy level and charge state of the interface state peak, we argue that it cannot be reliably ascribed to either Pb0 or Pb1.