Fabrication and characterization of a 2D hole system a in novel (311)A GaAs SISFET

We demonstrate a novel heterostructure for inducing 2D hole systems in (311)A GaAs-AlGaAs heterostructures that offers advantages over previous methods including low turn on voltages, easier fabrication and good interface roughness. The heterostructure incorporates a metallic p+-GaAs cap layer as an in situ top gate that pins the Fermi energy close to the valence band and can then be used to induce the 2D hole system at the GaAs/AlGaAs interface.