为提高InSb红外探测器室温下的工作性能, 设计了GaSb/InSb/InP异质结构, 并对结构中俄歇复合与肖克莱-瑞德复合两种复合机制对漏电流的影响进行研究。利用TCAD仿真工具对InSb探测器件进行建模, 分析得到能带结构与载流子分布。以能带参数为基础, 根据连续性方程, 结合漂移扩散模型, 分析了俄歇复合在反偏压下的衰减效应, 并综合肖克莱-瑞德复合的影响, 计算出不同缺陷浓度下器件的漏电流。利用低压金属有机化学气相沉积(LP-MOCVD)技术制备GaSb/InSb/InP异质外延样品, 对其漏电流进行测试, 并与仿真结果进行对比分析。实验结果表明, 计算结果与实验结果一致, 器件工作性能的主要限制为肖克莱-瑞德复合机制, 器件的漏电流为0.26 A·cm-2, 品质因子R0A为0.1 Ω·cm2。相比于同质InSb结构, 器件的R0A提高了一个数量级, 已接近实用化水平。

In order to improve the performance of InSb infrared photo detectors operating at room temperature, a hetero-junction structure of GaSb/InSb/InP was proposed, and the contribution of Auger mechanism and Shockley-Read-Hall(SRH) mechanism to the leakage current was investigated. A theoretical model was established using TCAD tools, to obtain the band structure and carrier distribution. Then a simulation of the suppression of Auger mechanism under reverse bias and the total leakage current including Shockley-Read mechanism with different impurity concentrations was proceeded. The simulation was based on the carrier continuity equations, combined with the drift-diffusion transport model. Finally, samples were prepared using LP-MOCVD technique and a test of leakage current was carried out, and an analysis of the theoretical model and experiment data was presented. Experimental results indicate that the main limitation of the devices’ performance is SRH mechanism, and there is a well fit of the theoretical model with the experiment data. The leakage current of the sample is 0.26 A·cm-2, and R0A is 0.1 Ω·cm2. R0A of the device increases by an order of magnitude compared to the homo-junction structure, and the device is close to practical level.