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The dynamic behavior of dislocations in heavily germanium (Ge)-doped silicon (Si) crystals with concentrations up to 2.5 × 10[sup 20] cm[sup -3], and Ge and boron (B) codoped Si crystals with concentrations of 4×10[sup 19] and 9×10[sup 18] cm[sup -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. [ABSTRACT FROM AUTHOR]

The dynamic behavior of dislocations in highly boron (B)-doped Si crystals with concentration up to 2.5x10[sup 20] cm[sup -3] is investigated using the etch pit technique. Suppression of the generation of dislocations from a surface scratch is found for B-doped Si and the critical stress for dislocation generation increases with B concentration, which is interpreted in terms of dislocation locking due to impurity segregation. The velocity of dislocations in B-doped crystals is revealed to increase by increasing the B concentration. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Spatially resolved electrical and spectroscopic behavior around isolated grown-in dislocation in p-type undoped GaAs crystals grown by liquid-encapsulated Czochralski technique is investigated. Surface spreading resistance is found to remarkably increase at about 100 μm in diameter around dislocations. In a corresponding area, photoluminescence intensity of the 1.49-eV and 1.44-eV acceptor level peaks decreases. However, that of 0.8-eV deep level peak does not vary. These results demonstrate that dislocations should give rise to carrier density variation due to the relative concentration change of levels around them. [ABSTRACT FROM AUTHOR]

Abstract: Dynamic interaction between dislocations and impurities in Si is investigated by using X-ray topography and the etch-pit technique from the viewpoint of Czochralski growth of Si crystals. Dislocation generation is effectively suppressed by doping of B and co-doping of B and Ge, which is originating in the immobilization of dislocations by preferential segregation of impurities. Dislocation velocity in motion is enhanced by increasing the concentration in B impurities. Change of the lattice parameter due to the impurity doping leads to the generation of misfit dislocations at the seed/crystal interface. [Copyright &y& Elsevier]