Reduction of the effective height of metal–n-InP Schottky barriers using thin epitaxial layers

Reduction of the effective height of metal–n-InP Schottky barriers from 0.4 to 0.24 eV has been achieved by utilizing thin epitaxial n+ surface layers which are fully depleted at zero bias. A novel ’’ramp-etching’’ technique has been used to investigate the effect of n+ thickness on current-voltage characteristics and shows that further effective reductions are possible using thicker n+ layers which are not depleted at zero bias. Low height barriers of this type have applications in high-efficiency transferred electron microwave oscillators.