Aa. Klechko et al., Enhanced formation of thermal donors in irradiated germanium: local vibrational mode spectroscopy, SEMICONDUCT, 33(11), 1999, pp. 1163-1165
Oxygen-rich Ge samples were bombarded with fast electrons (E=4 MeV) at 80 d
egrees C and subjected to isochronal (100-340 degrees C) and isothermal (35
0 degrees C) annealing. Infrared absorption spectra were measured at room t
emperature. Preliminary irradiation of the samples is found to strongly enh
ance the development of the absorption bands in the range 600 to 780 cm(-1)
when the Ge < Sb,O > crystals are heated to 350 degrees C. The bands are a
ssigned to local vibrational modes of thermal donors. It is inferred from t
he annealing studies that a radiation-induced complex with the local vibrat
ional modes at about 770-780 cm(-1) is probably responsible for the enhance
d growth of the thermal donors. Oxygen dimers are proposed as such a comple
x. (C) 1999 American Institute of Physics. [S1063-7826(99)00211-2].