Metal-Semiconductor-Metal Photodetectors for Optical Interconnect Applications.

A method of lowering the dark current of silicon metal-semiconductor-metal MSM photodetectors was developed. MSM photodetectors have been the focus of much recent research. The monolithic design, integratability with standard VLSI circuitry, high speed performance, and applicability to 2-D array layouts make them a good candidate for optical interconnect architectures. In many optical interconnect schemes, the combination of low optical power emission from optical sources, low cost and low efficiency optical guiding or focusing systems and realistic alignment limitations often result in low optical signal level reaching the photodetector. To maintain an adequate signal to noise ratio for high data rates, the noise contributed by each component in the interconnect scheme must be minimized. This report reviews MSM photodetector operating characteristics, fabrication, and an analysis of a method of reducing the detector dark current.