A PHYSICS-BASED TUNNELING MODEL FOR SB-HETEROSTRUCTURE BACKWARD TUNNEL DIODE MILLIMETER-WAVE DETECTORS

Abstract

InAs / AlSb / GaSb heterostructure backward tunnel diodes are sensitive millimeter-wave detectors that achieve their high sensitivity by leveraging interband tunneling current in a broken-gap heterostructure. A new physics-based tunneling model that accurately reproduces experimental results is proposed in this work. This model, which uses Kane's eight-band k · p band structures and tunneling coefficients calculated using the transfer matrix method, predicts IV curves that closely match measured data. It also predicts critical device parameters for detector performance (including curvature coefficient and junction resistance) as a function of device structure, and good agreement with experiment results has been obtained. It accurately predicts the junction resistance's exponential dependence on tunnel barrier thickness, as well as more subtle effects such as the impact of cathode doping profile adjustment and anode ternary composition. The predictive capabilities of this model are promising to provide guidance for future detector heterostructure optimization and may be useful in modeling the characteristics of other heterostructure designs and devices using 6.1 Å lattice constant materials.