Design and simulation of high performance metal-semiconductor-metal photodetectors

Includes bibliographical references (pages [96]-100)Metal-semiconductor-metal (MSM) photodetectors are used in the optoelectronic integrated circuit (OEIC) receivers because they are compatible with the preamplifier for their planar integration scheme, the minimum number of processing steps, high performance (high sensitivity, high frequency response speed, and low noise), and low cost. Design and simulation of high performance MSM photodetectors is the purpose of this work. In this work, theory and characteristics of MSM photodetectors are studied. Various researches on high performance MSM photodetectors are reviewed. As one of the main work in this thesis, various MSM photodetector structure parameters, which include finger width, finger spacing, finger number, detection area size, active layer thickness, and some others, are simulated to obtain optimum MSM photodetectors. Another main work is the low temperature process technology of Schottky contacts and corresponding simulation on InGaAs/InP MSM photodetectors for long wavelength detection. Schottky barrier heights are significantly enhanced with low temperature technique, which greatly suppresses the dark current leakage of MSM photodetectors. The simulation shows that the current leakage is reduced higher than 6 orders in magnitude. The fabrication of MSM photodetectors is simplified with low temperature technique compared to conventional Schottky barrier enhancement layer techniques. The Schottky contact processing and the simulation results in this thesis show us that the low temperature InGaAs MSM photodetectors with suitable structure are very competitive for the future OEIC receivers at long wavelength range.M.S. (Master of Science