Ohmic versus rectifying contacts through interfacial dipoles: Al/InxGa1-xAs

The Schottky barrier height at Al/n-InxGa1-xAs contacts (0.19<x<0.38) was engineered by fabricating Si bilayers at the metal-semiconductor interface. Si interlayers grown under As flux led to the suppression of the barrier, while interlayer deposition under Al flux yielded an increase in the barrier height. In situ X-ray photoemission spectroscopy results and ex situ current-voltage measurements indicated a barrier tunability range of about 0.8 eV, with ideal ohmic behavior of diodes engineered for low barrier height, and barrier heights as high as 0.7 eV in diodes engineered for high barrier height.