In oxides fabricated by thermal oxidation or ion implantation, an order-of-magnitude increase is observed in the concentration of radiation-induced E' centers when the oxide is first exposed to H2 at temperatures greater than 600°C. To the authors' knowledge, we report the first data indicating that preirradiation hydrogen annealing of thermal oxides causes a large increase in the concentration of radiation-induced E' centers. We discuss evidence suggesting that the hydrogen anneal creates a new E' precursor, Si - H, from Si - Si bonds.
