High-speed Ga/sub 0.47/In/sub 0.53/As MISIM photodetectors with dielectric-assisted Schottky barriers

Abstract
A technique is described for fabricating high-speed metal-insulator-semiconductor-insulator-metal (MISIM) photodetectors for high-speed fiber-optic systems. These devices make use of a Langmuir-Blodgett film enhanced Schottky barrier to achieve broadband linear response to 13 GHz at low bias voltage (5 V) with approximately 0.9 A/W external responsivity, 15 V breakdown voltage, and approximately 2 mu A dark current. A gain of about 2 and a 5% tail in the temporal response are analyzed. The needed bias and the device processing are compatible with those for integrated receivers.