光载流子辐射测量的非线性初步分析

发布时间：2019-01-03 07:57

【摘要】：以硅晶为代表的半导体材料是电子器件和光伏器件的基础材料,材料的杂质缺陷特征影响器件性能,因此对表针材料的杂质缺陷特征的半导体电学特征参数,载流子输运参数的监测是非常重要的。现今,光学无损检测手段用于半导体材料的测量是半导体检测领域的热点和趋势。光载流子辐射测量技术(Photocarrier Radiometry,PCR)是一种全光、无损、动态调制的光学检测手段,可以实现半导体载流子输运参数(载流子寿命、扩散系数、表面复合速率等)的非接触测量。实验结果表明,PCR信号同激励光强之间存在非线性效应,传统的PCR理论模型中并没有考虑这个情况,因此本文主要对光载流子辐射测量技术的非线性特征对载流子输运参数测量的影响进行初步分析。本文首先围绕光载流子辐射信号非线性特征的相关物理机制进行展开,从半导体载流子产生复合过程,输运方程出发,理解载流子的运动行为,然后通过求解输运方程,阐述了载流子辐射信号相关表达式,最后根据普朗克辐射理论阐述了光载流子辐射信号与载流子浓度和半导体样品掺杂浓度的关系,给出了PCR强度响应非线性系数。根据光载流子辐射信号的理论关系式进行了理论仿真。进行了与光载流子辐射信号相关参数的具体仿真。仿真过程中围绕载流子输运参数和PCR强度响应非线性系数展开,给出了非线性模型和传统线性模型的适用条件,并且分析了本文讲述的PCR非线性模型下反演载流子参数的影响。搭建了利用透射光监测激励光强的光学实验平台,开展了光载流子辐射测量频率扫描和强度扫描实验。通过分析不同工艺不同电阻率样品的PCR强度响应非线性效应和载流子参数的具体反演结果,在实验上验证了PCR非线性和传统线性模型的适用情况。测量了不同电阻率样品的PCR强度响应和PCR频率响应,选取合适的拟合模型,得到了载流子输运参数,最后通过反演获得掺杂浓度测量样品的电阻率。
[Abstract]:The semiconductor material represented by silicon crystal is the basic material of electronic device and photovoltaic device. The impurity defect characteristic of the material affects the device performance, so the semiconductor electrical characteristic parameter of the impurity defect characteristic of the surface needle material is discussed. The monitoring of carrier transport parameters is very important. Nowadays, optical nondestructive testing (NDT) is a hot spot and trend in semiconductor measurement. Optical Carrier radiation Measurement (Photocarrier Radiometry,PCR) is an all-optical, non-destructive, dynamic modulation optical measurement method, which can realize the carrier transport parameters (carrier lifetime, diffusion coefficient) of semiconductors. Surface recombination rate, etc.) non-contact measurement. The experimental results show that there is a nonlinear effect between the PCR signal and the excitation intensity, which is not considered in the traditional PCR theory model. Therefore, the influence of nonlinear characteristics of optical carrier radiation measurement technology on carrier transport parameters measurement is primarily analyzed in this paper. In this paper, the related physical mechanism of nonlinear characteristics of optical carrier radiation signals is first discussed. From the semiconductor carrier generation recombination process, the transport equation, the motion behavior of carrier is understood, and then the transport equation is solved. The correlation expression of carrier radiation signal is expounded. Finally, according to Planck radiation theory, the relationship between optical carrier radiation signal and carrier concentration and doping concentration of semiconductor sample is discussed, and the nonlinear coefficient of PCR intensity response is given. The theoretical simulation is carried out according to the theoretical relation of the optical carrier radiation signal. The simulation of the parameters related to the optical carrier radiation signal is carried out. In the simulation process, the nonlinear parameters of carrier transport and the nonlinear coefficient of PCR intensity response are expanded. The applicable conditions of nonlinear model and traditional linear model are given, and the effect of inversion carrier parameters under PCR nonlinear model described in this paper is analyzed. An optical experimental platform is set up to monitor the intensity of excited light by transmission light, and the experiments of frequency scanning and intensity scanning of optical carrier radiation measurement are carried out. By analyzing the nonlinear effect of PCR intensity response and the specific inversion results of carrier parameters of different resistivity samples with different processes, the applicability of PCR nonlinear and traditional linear models is verified experimentally. The PCR intensity response and PCR frequency response of different resistivity samples were measured. The carrier transport parameters were obtained by selecting a suitable fitting model. Finally, the resistivity of the samples was measured by inversion.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN304.07

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