少数载流子寿命测试系统研究

Study on measuring system for minority carrier lifetime

少数载流子寿命是衡量半导体材料性能的关键参数之一 ,文中介绍了光电导衰退法少数载流子寿命测试系统。阐述了光电导衰退法测试原理 ,分析了测试系统构成 ,以及光脉冲下降沿时间、微弱信号放大处理、前放带宽、精密定位等关键技术 ,其主要性能指标是 :少数载流子寿命测试范围 :1× 10 - 7～ 6× 10 - 6s ;可测样品尺寸 :小于 2 0mm ;单色光光点大小 :Φ 0 .3mm ;测试数据稳定度优于 10 %。

The minority carrier lifetime is the key parameter of the semiconductor material. Through the study of minority carrier lifetime, the recombination mechanism of the carriers can be understood, thus the material can be sampled effectively. The yield and the performance of infrared detector will be raised. The minority carrier lifetime measuring system is designed by the method of photoconductive decay (PCD). The double refracting-reflecting optical system is adopted, so the sideview and bottom view of metal Dewars can be used for testing. There are two testing methods: Auto-test and Semi-Auto test. The range of the measuring system is from 1×10+{-7} to 6×10+{-6} sec.. The diameter of measured sample must be less than 20mm.