A behavioral model for high Ge content in Si/Si1-xGex multi-quantum well detector

Official URL: http://dx.doi.org/10.1109/JSEN.2018.2865033

This paper presents a behavioral model for a Si/Si1-xGex multi-quantum well (MQW) detector that predicts device characteristics to investigate the effect of increasing Ge content in Si/Si1-xGex MQW. The modeling approach in this work is based on a physical instead of empirical approach which allows to obtain a predictive behavioral analysis of high Ge content with only a few fitting parameters. The model is used to simulate device transfer characteristics with respect to various amounts of Ge content used for Si1-xGex layer in MQW. The simulation results of the proposed model are validated with the experimental data. The simulated and the experimental data are consistent over a wide range of Ge content varied from 30% up to 50%. The primary objective of this work is to optimize Ge content in Si/Si1-xGex MQW detector to achieve desired thermal sensitivity measured in terms of temperature coefficient of resistance (TCR) for a potential microbolometer application. This is the first study in the literature to develop such a highly predictive behavioral model of a Ge-enriched Si/Si1-xGex MQW. The study also presents the effect of including the carbon delta (C-delta) layers at the Si/Si1-xGex heterointerface on the device transfer characteristics. The effect of Ge content on the overall noise is also investigated by the noise characterization of the test devices.