By observing 0.1μ-sized light point defects in Czochralski-grown wafers during H annealing, it was found that the H-annealed wafers had fewer defects on their surfaces; as compared with a polished wafer. By assuming that the light point defects were equivalent to crystal-originated particles (O precipitates and/or vacancy-type defects), light point defects could be reduced in number by evaporating O from the surface, and migrating Si atoms onto the surface during H annealing (1200C, 1h).

K.Izunome, M.Miyashita, A.Ichikawa, Y.Kirino, J.Arita, A.Ueki: Japanese Journal of Applied Physics - 2, 1997, 36[9A-B], L1127-9