锑化物中波 APD 的设计与优化

Design and optimization of mid-wavelength avalanche photodiodes based on antimonides

摘要:

本文针对中波弱光探测下线性模式 APD 的需求,设计基于 InAs/GaSb 二类超晶格和 AlGaAsSb 四元合金分别作为吸收层和倍增层的雪崩光电探测器。通过构建 AlGaAsSb合金的碰撞电离模型,基于 SILVACO-ATLAS 仿真平台较为系统的模拟了倍增层厚度及掺杂浓度、吸收层厚度及掺杂浓度等结构参数对器件 I-V 特性、电场分布以及瞬态响应的影响,从而获得最佳的模型参数以减小暗电流和提高增益。同时,也探究了不同温度对器件性能的影响。仿真结果显示在 300 K 下,在工作电压下的增益为 16.4,在击穿电压处的最大增益为 129.5,比探测率为 2.39×101¹ cm.Hz 1/2^.W-1^{。该研究可为在室温下工作的中波红外雪崩光电二极管提供理论基础。}

Abstract:

In order to meet the demand of linear APD in low-light detection, an avalanche photodetector based on InAs/GaSb second-class superlattice and AlGaAsSb quaternary alloy as absorption layer and multiplier layer is designed in this paper. By constructing a collision ionization model for the AlGaAsSb alloy and using the SILVACO-ATLAS simulation platform, the effects of structural parameters such as multiplication layer thickness and doping concentration, absorption layer thickness and doping concentration on the device"s I-V characteristics, electric field distribution, and transient response are systematically simulated. This aims to obtain the optimal model parameters to reduce dark current and improve gain. Additionally, the influence of different temperatures on device performance is explored. Simulation results show that at 300 K, the gain at the operating voltage is 16.4, and the maximum gain at the breakdown voltage is 129.5, with a specific detectivity of 2.39×1011 ^cm.Hz1/2^.W-1. This research provides a theoretical basis for the development of medium-wave infrared avalanche photodiodes operating at room temperature.