Design, Fabrication and Characterisation of High Speed GaAs MSMs for OEIC Applications

Abstract

GaAs optoelectronic integrated circuits (OEICs) are rapidly finding use in a variety of communications and signal processing applications such as high speed, broadband switching (up to 10 Gbits/s and higher), high speed interconnects for multi-processor LANs and space-based, optically controlled phased array radars and antennas for next generation personal communications. One of the key elements in any of these circuits is the photodetector, which serves as the front end receiver, converting optical input signals from the fibre optic network, into electronic signals which can be processed by subsequent electronic circuitry. Planar Metal-Semiconductor-Metal (MSM) photodetectors are particularly attractive as the receiving element in these circuits. They offer a combination of high speed, wide bandwidth and low power consumption and can be easily integrated with conventional GaAs MESFET circuit technology¹. In this paper the design, fabrication and characterisation of GaAs MSMs and MSM-based OEICs is discussed.