An integrated amorphous silicon photodetector for optical interconnections

Very large scale integrated (VLSI) circuits are becoming more complex and dense. Although providing more computing power, they also require more interchip and intrachip communication capabilities. Optical interconnections have been recognized as one possible solution to the interconnection problem. For a detector in an optical interconnection, it is important that most of the chip area be dedicated to processor and memory circuits.; A hydrogenated amorphous silicon p-i-n diode is a good choice as a photo detector for optical interconnetion due to its high sensitivity, low cost, low deposition temperature and high speed. It can also be deposited on top of a silicon chip so that the entire chip area can be dedicated to processor and memory circuits. Compared to a differential detector scheme which requires double the unit area, amorphous silicon detectors on top of the silicon chip have obvious advantages. In this dissertation, we report our feasibility analysis of a-Si:H photo diodes for this application.; The major contributions of this dissertation are (1) designing and building an integrated photo detector for high speed photo interconnections, which includes a clamped bit line sensing amplifier (CBLSA), comparator and inverter chain, (2) building a simple yet sufficient model for a hydrogenated amorphous silicon p-i-n diode, (3) characterizing the transient performance of the p-i-n diode under strong reverse bias and light modulation, (4) studying the mismatch effect and developing current bias technique to compensated for the mismatch effect, and (5) exploring the ideas to, improve the overall performance of the integrated photo detector.