TRANSMISSION ELECTRON-MICROSCOPE INVESTIGATION OF INDENTATION INDUCEDDISLOCATION CONFIGURATIONS ON THE (001) GASB FACE

Dislocation configurations induced by room temperature microindentatio ns on the (001) face of GaSb (undoped and Te-doped) have been studied using high voltage transmission electron microscopy. Perfect and parti al dislocations could be found in all four arms of the dislocation ros ette around the indent. Microtwins and rarely single stacking faults a re associated with the partials. Contrary to other binary III-V compou nds, an ''inverse'' glide prism along the [110BAR]/[110BAR] rosette ar ms is created and it is bounded by {111}B planes which diverge away fr om the surface. Under high stress-low temperature conditions plastic d eformation in undoped as well as n-doped GaSb proceeds by the movement of mobile alpha-dislocations, whereas beta-dislocations are almost im mobile. The reasons for the observed slip asymmetry of the dislocation rosette are discussed and a model for the formation of microtwins is proposed.