ROOM-TEMPERATURE CURRENT IMAGING TUNNELING SPECTROSCOPY OF GAAS ALGAAS QUANTUM WIRES AT AMBIENT-PRESSURE/

Scanning tunnelling microscopy studies on (100) surfaces of GaAs/AlGaA s quantum wire structures in dry nitrogen ambient are reported. Even a t room temperature distinct local differences between I-V curves taken on wet chemically etched GaAs/AlGaAs inverted heterostructures are fo und. This enables us to clearly observe quantum wire regions with curr ent imaging tunnelling spectroscopy at 300 K. The spectroscopic differ ence can be ascribed to the internal potential profile in the subsurfa ce regions of the sample, rather than to a changed dopant concentratio n.