The nature of a 2050–2150‐cm−1 infrared band in neutron‐transmutation‐doped silicon grown by the floating‐zone method in a hydrogen atmosphere

A strong, wide infrared absorption band in 2050–2150‐cm−1 range has been found in neutron‐transmutation‐doped silicon grown by the floating‐zone method in a hydrogen atmosphere and annealed at 650 °C. This band is due to the stretching vibration of the Si–H bond, formed as hydrogen atoms diffuse, aggregate, and saturate silicon dangling bonds in the neutron‐irradiation disordered region. This absorption band is similar to that of hydrogenated amorphous silicon in the 1900–2150‐cm−1 range except that its vibration frequency is somewhat higher. The disordered region defect and its amorphous‐siliconlike property could be observed because of the incorporation of hydrogen. The hydrogen concentration of the floating‐zone melted silicon grown in a hydrogen atmosphere used in this study is estimated to be (1–2)×1017 cm−3 on the basis of the strength of this wide infrared absorption band. A possible reason for this vibration frequency shift is discussed.