Material and electrical properties of N-polar (GaN)/InN surfaces

Angle-resolved XPS-analysis of the bare InN surface has revealed surface electron accumulation and negative band bending by about 0.65 eV at a distance of 1.1 nm. On the other hand this effect was substantially reduced by capping the InN surface by 2 to 4 monolayer of GaN. Negative polarisation charge at the GaN/InN interface of (partially) strained cap layer together with elimination of dangling bonds at the InN surface were consequently suggested. RIE in CCl₂F₂ provided highly selective etching of GaN over InN. Al₂O₃ deposited by ALD on (GaN)/InN surface created structures with metal-insulator-metal-like behaviour.