Employing hydrogen depth-profiling via 1H(15N,αγ)12C nuclear reaction analysis (NRA), the “native” H concentration in thin (19–41.5 nm) SiO2 films grown on Si(100) under “wet” oxidation conditions (H2+O2) was determined to be (1–2)×1019 cm−3. Upon ion-beam irradiation during NRA this hydrogen is redistributed within the oxide and accumulates in a ∼8-nm-wide region centered ∼4 nm in front of the SiO2/Si(100) interface. Annealing in H2 near 400 °C introduces hydrogen preferentially into the near-interfacial oxide region, where apparently large numbers of hydrogen trap sites are available. The amount of incorporated H exceeds the quantity necessary to H-passivate dangling Si bonds at the direct SiO2/Si(100) interface by more than one order of magnitude. The H uptake is strongly dependent on the H2-annealing temperature and is suppressed above 430 °C. This temperature marks the onset of hydrogen desorption from the near-interfacial oxide trap sites, contrasting the thermal stability of the native H, which prevails homogeneously distributed in the SiO2 films after oxidation at 900 °C. Hydrogen bound in the near-interface oxide region is not redistributed by the ion-beam irradiation, further emphasizing its different chemical interaction with the SiO2 network as opposed to the native oxide H. The mechanism of the irradiation-induced H redistribution and its possible relation to the degradation of electrically stressed electronic devices are discussed.

Wilde, M., Matsumoto, M., Fukutani, K., Liu, Z., Ando, K., Kawashima, Y., & Fujieda, S. (2002). Influence of H2-annealing on the hydrogen distribution near SiO2/Si(100) interfaces revealed by in situ nuclear reaction analysis. Journal of Applied Physics, 92(8), 4320–4329.