Metal-semiconductor-metal photodetectors for optoelectric receiver applications

t has been found that the barrier height lowering observed in reverse-biased Schottky junction is due mainly to the change in electrical potential across the interfacial layer at the metal-semiconductor contact. The voltage dependence of barrier height is described, and excellent agreement with experimental data is shown. The surface state density and interfacial layer thickness of a (Ti/Au) /n-InAlAs Schottky junction are estimated from its I-V characteristics. The expressions of the barrier heights of junctions in a metal-semiconductor-metal photodiode (MSMPD) are derived, and excellent agreement with experiment is shown. The adjustment of barrier height and dark current by annealing is investigated based on the theory. The merit of transparent electrodes for MSMPD in an optoelectronic-integrated-circuit (OEIC) is described, and it is shown that the signal-to-noise-ratio (SNR) of a receiver can be improved by the employment of transparent electrodes.;The design, fabrication, and characterization of MSMPDs for long-...