Radiation-induced shallow donors in Czochralski-grown silicon crystals saturated with hydrogen

Abstract

Far-infrared absorption has been investigated in n-type Czochralski-grown silicon saturated with hydrogen and then irradiated with fast electrons. Two series of absorption bands in the range 200–330 cm−1 are observed upon postirradiation annealing of the crystals at 300–550 °C. These bands are associated with ground–to–excited-state electronic transitions in two kinds of shallow donors with ionization energies of 37.0 and 42.6 meV, which are described well with the effective-mass approximation. These donors are related to defects observed earlier in electrical measurements.