Modeling, Design, and Fabrication of Self-Doping Si1−xGex/Si Multiquantum Well Material for Infrared Sensing

Bo Jiang,Tao Dong,Yong He,Dandan Gu,Yulong Zhang,Yan Su

doi:10.1155/2016/6584650

Abstract

The paper presents the study of band distributions and thermoelectric properties of self-doping Si1−xGex/Si multiquantum well material for infrared detection. The simulations of different structures (including boron doping, germanium concentrations, and SiGe layer thickness) have been conducted. The critical thickness of SiGe layer grown on silicon substrate has also been illustrated in the paper. The self-doping Si1−xGex/Si multiquantum well material was epitaxially grown on SOI substrate with reduced pressure chemical vapor deposition. Each layer of the material is clear in the SEM. TheI-Vcharacterizations and temperature resistance coefficient (TCR) tests were also performed to show the thermoelectric properties. The TCR was about −3.7%/K at room temperature in the experiments, which is competitive with the other thermistor materials. The material is a low noise material, whose root mean square noise is 1.89 mV in the experiments.

Highlights

Bolometer, one of uncooled infrared detectors, has been widely developed since 1992, when the “bridge structure” was reported by Honeywell
The self-doping Si1−xGex/Si multiquantum well material was epitaxially grown on SOI substrate with reduced pressure chemical vapor deposition
The special process line should be provided for vanadium oxide manufacture, which would be expensive in bolometer development

Summary

Introduction

One of uncooled infrared detectors, has been widely developed since 1992, when the “bridge structure” was reported by Honeywell. The special process line should be provided for vanadium oxide manufacture, which would be expensive in bolometer development. With the rising complexity in this process, the cost and difficulties increase to maintain the lattice quality. The high TCR material with selfdoping Si1−xGex/Si MQWs films was presented to solve the problems. The material has a thin buffer layer, where a proportion of boron atom diffusion is allowed [12] This structure simplifies the process and can promise a high lattice quality through epitaxial growth processes, such as the reduced pressure chemical vapor deposition (RPCVD) and molecular beam epitaxy (MBE). The results show that the lattice of self-doping Si1−xGex/Si multiquantum well material has good quality and the TCR is −3.7%/K, which is high compared with other material in the reports [13]

Energy Bands Modeling and Design

Fabrication and Test

Results and Discussion

Conclusions