FAR-INFRARED PHOTOCONDUCTIVITY OF SILICON IRRADIATED WITH FAST-NEUTRONS

Far-infrared photoconductivity with photon energies less than the ioni zation energy of a hydrogen-like donor, calculated in the effective-ma ss approximation, was observed in weakly doped, weakly compensated Czo chralski-grown silicon after irradiation with fast neutrons, followed by annealing. The photoconductivity is associated with the photoioniza tion of clusters consisting of shallow donor centers, which appeared a s a result of bombarding silicon with fast neutrons followed by anneal ing. It is assumed that the donor centers contain magnesium atoms whic h are produced by the transmutation of the isotopes Si-28 and Si-29. ( C) 1995 American Institute of Physics.