In our investigations, Au, Al, Ni, Pt, Ti, and combinations thereof were deposited on InP and InGaAs by e-beam evaporation to form Schottky contacts. The Schottky-barrier heights of these diodes determined by forward I–V and (or) reverse C–V measurements lie between 0.38–0.48 eV. To increase the Schottky-barrier height, a strained GaxIn1−xP layer was inserted between the electrode metal(s) and the semiconductor. This material, which has a band-gap larger than InP, was grown by gas-source molecular beam epitaxy. The Schottky-barrier heights, which generally depend on the gallium fraction, x, and the thickness of the strained GaxIn1−xP layer, increase and are in the range of 0.56–0.65 eV in different contact schemes.
