Truly ohmic contacts in engineered Al/Si/InGaAs(001) diodes

We report the fabrication of nonalloyed ohmic contacts on n-InxGa1−xAs (0.25⩽x⩽0.38) grown by molecular beam epitaxy (MBE) on GaAs(001). This result is obtained by suppression of the native Al/InGaAs Schottky barrier by means of the MBE growth of Si bilayers at the metal-semiconductor interface. Truly ohmic contacts are demonstrated by x-ray photoemission spectroscopy and current-voltage techniques.