Metal contacts to GaAs with 1 eV Schottky barrier height

Metal Schottky barrier contacts to n-type (100) GaAs are described in which a 1 eV Schottky barrier height φB is achieved by using a very thin Si interface layer to influence the interface Fermi energy EiF. The metals investigated are Au, Cr, and Ti. The contact structure consists of a thick metal in combination with a ∼15–30 Å heavily p-type Si interface layer. The EiF and interface composition during initial contact formation were obtained by x-ray photoemission spectroscopy (XPS); the φB for the corresponding thick contacts was measured by current-voltage (I-V) and capacitance-voltage (C-V) techniques. The XPS, I-V, and C-V measurements gave consistent results. The 1 eV φB for the Si interface layer contact structure is independent of the contact metal.