Defects in NTD MCZ Si doped with magnesium

The doping phenomena of Si single crystals grown under an applied magnetic fields due to formation of Mg-related centers as a result of transmutation reaction of 28Si and 29Si isotopes after irradiation by fast neutrons is shown. The postradiation annealing at high temperatures leads to the formation of shallow and deep donor centers and to a smoothing effect on the structure of the MCZ NTD crystals: the separate microdefects are not revealed by x-ray topography and the striations related with the microdefects distribution are not observed. Far infrared photoconductivity at the photon energies lower than hydrogen-like ionization energy calculated in the effective mass approximation is observed. The photoconductivity is associated with shallow donor centers that include the magnesium atoms.