Matching-Circuit-Integrated InGaAsP Schottky Barrier Diode for Zero-Biased Operation in the Sub-Millimeter-Wave Range

An InP/InGaAsP Schottky barrier diode (SBD) for zero-biased operation in the sub-millimeter-wave range has been designed and fabricated. The SBD is monolithically integrated with a short-stub resonant matching circuit to increase the detection sensitivity around the designated frequency as well as to provide a biasing circuit. The fabricated device exhibits a small Schottky barrier height of about 0.37 eV, which is suitable for zero-biased operation. The SBD chip is mounted in a compact J-band (WR-3) rectangular-waveguide-input module to evaluate the high-frequency characteristics. The module exhibits a peak sensitivity at around 350 GHz due to the characteristics of the matching circuit, and good linearity of the output voltage against the input sub-mm-wave power. A record sensitivity of 1460 V/W at 350 GHz is obtained for the InP-based zero-biased SBD.