Direct observation of electrical charges at dislocations in GaAs by cross-sectional scanning tunneling microscopy

We demonstrate the possibility of simultaneous determination of the type an d electrical charge state of dislocations in GaAs by cross-sectional scanni ng tunneling microscopy (STM). The methodology is demonstrated for a dissoc iated perfect dislocation in highly Si-doped GaAs(110) surfaces. The STM im ages of the dislocation penetrating GaAs cleavage surface show that both pa rtial dislocation cores as well as the stacking fault between the two parti al dislocation cores are negatively charged. (C) 2001 American Institute of Physics.