半导体材料特性的腔衰荡检测方法研究

The performances of semiconductor materials and devices are usually improved along with the development of testing methods. The optical testing methods have being widely used in real-time measurement of semiconductor materials processing and real-time monitoring of processing quality, due to the advantages, such as fast and no damage. However, the measurement accuracy of the current optical testing methods commonly used in industry are limited by many theorical and experimental factors. Based on free carrier absorption theory, the electronic transport parameters are measured accurately using cavity ring-down method in this project. The theoretical model are established to analyze the relationship between the cavity ring signal and the electronic transport parameters. The effects of material properties and experimental conditions on ring down signal are theoretically simulated and approved experimentally. The measurement accuracy, sensitivity and precision of parameters are also analyzed. In addition, by measuring the injection and temperature dependence of the electronic transport parameters, combined with the absorption spectrum of the semiconductor, the physical mechanism of defects can be explored. As its high accuracy and simple device, this research has great potential for industrialization.

半导体材料与器件性能的提高通常伴随着检测方法的发展。光学检测方法由于快速无损伤等优点被广泛应用于半导体材料加工过程的实时测量和加工品质的实时监控。但是，目前工业上常用的光学检测方法仍然由于理论和实验中诸多因素的影响限制其测量精度的进一步提高。本项目基于自由载流子吸收理论，采用腔衰荡方式对半导体材料特性参数进行精确测量研究。建立腔衰荡信号与材料特性参数关系的理论模型，对材料特性和实验条件对衰荡信号的影响进行理论模拟和实验验证，同时对测量参数的准确性、灵敏度和精度进行分析。另外，通过测量不同注入水平和不同温度下半导体材料特性参数，结合材料的吸收谱特性，探索缺陷产生过程和物理机理。由于测量精度高且装置简单易于仪器化，本项目的研究具有巨大的产业化潜力。

本项目采用腔衰荡法对半导体材料特性参数进行了无损测量。通过建立基于腔衰荡的半导体材料特性测量技术理论模型，对腔衰荡信号与半导体材料特性的关系和参数测量灵敏度进行了详细的理论分析。基于理论模型和仿真结果，搭建了实验光学测量系统，对半导体材料特性参数进行实验测量和分析，结果证实了该技术可以有效应用于半导体材料性能检测中，如掺杂浓度及其均匀性的测量等。当采用不同激励波长进行泵浦时，还可以对载流子的相关特性进行测量表征。同时，该方法可应用于半导体材料材料的离子注入及退火工艺过程的实时测量。