Dynamic characteristics of dislocations in Ge-doped and (Ge+B) codoped silicon

The dynamic behavior of dislocations in heavily germanium (Ge)-doped silicon (Si) crystals with concentrations up to 2.5×1020 cm−3, and Ge and boron (B) codoped Si crystals with concentrations of 4×1019 and 9×1018 cm−3, respectively, is investigated using the etch pit technique in comparison with that in undoped and B-doped Si crystals. Strong suppression of the generation of dislocations from a surface scratch is found for Ge and B codoped Si in comparison with that observed for Ge-doped and B-doped Si. The velocity of dislocations in Ge and B codoped Si crystals is found to be lower than that of dislocations in B-doped, Ge-doped, and undoped Si. The coexistence of Ge and B impurities in Si is considered to be effective at immobilizing and retarding the velocity of dislocations in Si.