摘要
对红外透射光谱法测定HgCdTe液相外延材料纵向组分分布技术进行了深入的研究.红外透射光谱的理论计算采用了王庆学提出的组分分布模型,并考虑了光穿越组分梯度区时产生的干涉效应.通过测量同一样品在不同外延层厚度下的一组红外透射光谱,该方法的有效性得到了实验验证.进一步对组分模型中参数(即外延总厚度、组分互扩散区厚度、材料表面组分和HgCdTe层组分梯度)的拟合方法进行了讨论,并确定了各拟合参数的拟合精度.结果显示,该方法可作为测定HgCdTe液相外延材料组分特性的一种有效的测试评价技术.
The longitudinal composition profiles of HgCdTe LPE films based on infrared transmission spectra are evaluated. The infrared transmission spectra are simulated theoretically using the composition profile model proposed by Wang Qingxue, taking the interference effect of the light during propagation in the composition gradient region of HgCdTe LPE films into consideration. A set of infrared transmission spectrum curves of the samples with the same growth number but different HgCdTe layer thicknesses are used to check the reliability of the calculation method. The results show that all the experimental curves can be fitted theoretically. Next, a method to determine the 4 simulation parameters （HgCdTe epilayer thickness,composition gradient region thickness,surface composition, and composition slope in the epilayer） used in theoretical calculation is discussed and the precisions of these parameters are determined. The results show that the theoretical simulation of the infrared transmission spectra is effective to evaluate the longitudinal composition profiles of the HgCdTe LPE films.
