GaAs wafers possessing facet-dependent electrical conductivity properties

Abstract

Intrinsic GaAs(100) and (111) wafers were cut to expose {110} side faces for facet-specific electrical conductivity measurements. Using tungsten probes to make electrical contacts with the wafers, the {111} surface displays much larger current than the {100} and least conductive {110} surfaces, showing that facet-dependent electrical properties are also observable in GaAs crystals. Different degrees of surface band bending are used to explain the electrical facet effects. While symmetric I–V responses were collected for the {100}/{110} facet combination, asymmetric I–V curves were recorded for the {110}/{111} facet combination. Adjusted band diagrams with tunable surface band bending are presented to explain the current-rectifying behaviors. The current rectification effect can be applied to fabricate novel transistors.