Origin of an absorption band peaked at 5560 cm(-1) and related to divacancies in Si1-xGex

It is found that two types of centers are formed in Si1- xGex single crysta ls as a result of irradiation with fast electrons: divacancies (V-2) charac teristic of silicon and the V-2* centers; the latter are complexes of divac ancies V-2 with germanium atoms (V2Ge). It is shown that an absorption band peaked at about 5560 cm(-1) is a superposition of two absorption bands tha t correspond to the above centers. The V-2 divacancies diffuse during isoch ronous heat treatment and interact with germanium atoms, thus giving rise t o additional V-2* centers. The latter have a higher thermal stability than the V-2 centers do, and their annealing temperature increases with increasi ng content of germanium. (C) 2001 MAIK "Nauka/ Interperiodica".