不同衬底上InGaAs探测材料中位错行为与器件性能关联研究

To meet the demands of space remote sensing and detection applications, short-wave infrared detectors with low dark current density should be developed. But even larger lattice mismatch will generate between the InxGa1-xAs (x>0.53) layer and substrates. Thus defects controlling would be the key scientific problem and core technology for fabrication of InGaAs photodetectors with response wavelength >1.7 μm. However, there are few researches on the relationship and mechanisms of dislocation actions and device performances in this field. This project intends to start from the dislocations in the InGaAs photodetector structures with large lattice mismatch, and will study the dislocation behaviors both microscopically and macroscopically. We will compare and correlate the dislocations and device performances of InGaAs photodetector structures on highly mismatched substrates. The mechanisms how dislocations affect the performances of photodetectors will be analyzed both from theories and experiments. The implementation of this project will provide valuable knowledge and accumulate key technology for the choice of device structures and the evaluation of the performances of semiconductor materials and devices on highly mismatched substrates.

面向航天遥感与空间探测需求应用的短波红外探测器要求极低的暗电流密度，而较高In组分的InxGa1-xAs（x>0.53）探测材料与衬底间的失配更大，因此缺陷控制成为截止波长大于1.7微米InGaAs探测器材料制备的首要任务。但目前尚缺乏针对波长扩展InGaAs探测材料中位错行为和器件性能关联性及机理的深入研究。本项目将以InP和GaAs衬底上较大失配InGaAs探测材料中的位错为切入点，采用微观分析与宏观的材料及器件性能对比分析的方法，研究不同衬底上较大失配InGaAs材料中的位错行为，获得位错行为与器件性能之间的关联性，揭示位错的微观行为影响器件宏观性能的机理。本项目将从理论上为研制大失配衬底上半导体光电器件的结构优选和性能评估提供科学依据和关键核心技术积累。

本项目的执行严格按照原研究计划逐步开展，并提前顺利实现原定研究目标，即以InP和GaAs衬底上较大失配的高In组分InGaAs探测材料的GSMBE生长为研究基础，分析了较大失配InGaAs材料中位错产生、形成及演变过程，发展了出切实可行的较大失配材料中穿透位错密度的测试方法，明确了不同衬底上失配材料中位错行为的区别与共性，阐述了材料中的位错行为与较大失配高In组分InGaAs探测器材料与器件性能之间关联性，获得了InP和GaAs衬底上不同失配的InAlAs异变缓冲层位错控制的理论基础，这些研究成果将最终为具有较大失配的高性能光电器件研制和择优提供科学依据。