量值恒定的表面光电压法测量半导体少子扩散长度的研究

Study on Minority Carrier Diffusion Length by Surface Photovoltage with Constant Measure

为了在保持材料完整性的基础上,对单晶硅材料的质量进行评价,设计了一种利用表面光电压测量半导体少子扩散长度的系统。系统采用斩波器、单色仪和锁相放大器来获取半导体表面光电压信息,利用表面光电压与材料的光吸收系数的关系得出半导体少子扩散长度。重点阐述了系统的测量原理及各个模块的设计与实现方法。检测结果表明,量值恒定的表面光电压法用于测量半导体少子扩散长度能达到预期的效果。

To evaluate the quality of monocrystal silicon materials,a system using surface photovoltage to mesure the minority carrier diffusion length of semiconductor is designed based on keeping the integrity of materials.The system can be used to obtain the surface photovoltage by the methods of chopper,monochromator and lock-in amplifier.The minority carrier diffusion length of semiconductor is obtained by analyzing the relationship between the surface photovoltage and the optical absorption coefficient of materials.The measuring principle of the system and the realizing methods for all models are explained in detail.The experimental results show that the surface photovoltage method with constant measure can meet the excepted requirements.