Modeling of the Buried Multiple Junction (BMJ) Detector in Reach-Through (RT) Conditions

A physically-based model of the Buried Multiple Junction (BMJ) detector has been established with consideration of the device operation in reach-through (RT) conditions. In such a condition, the breakdown voltage of one junction can shift depending on its adjacent junction's bias voltage. The modeling approach consists in detecting RT conditions, determining depletion limits, electrostatic potential barrier height and thermionic emission current. It allows computations of the detector's dark currents and spectral responses to monochromatic light illumination. Computations of the detector's static characteristics have been compared with TCAD simulations and they are in good agreement, which is a model validation. The proposed model explains and determines the detector's breakdown voltage shift behavior, as well as its changes of spectral responses depending on bias voltages.