The effect of etching, in acid solutions, upon the energy spectrum of n- and p-type crystals which had been irradiated with high-energy electrons was studied by means of deep-level transient spectroscopy. It was observed that, as well as well-known radiation defects, a number of novel deep-level centers appeared near to the etched surface. The depth profiles of the deep-level centers were investigated as a function of the irradiation dose and the subsequent temperature annealing. The novel centers which were observed were shown to be complexes of radiation defects with H atoms that had penetrated into the crystal during etching. The development of some of these centers from particular vacancy-related defects was established. A simple quantitative description was provided for H atom penetration during etching, and for the formation of the H-defect complexes. On the basis of this analysis, the radius of H capture to the well-known A-center (vacancy-O complex) was estimated and a center with an energy level of Ec - 0.32eV was identified as being a complex of the A-center with two H atoms.

O.V.Feklisova, N.A.Yarykin: Semiconductor Science and Technology, 1997, 12[6], 742-9