Evaluation of the Composition Profile of HgCdTe LPE Films by IR Transmission Spectrum
HgCdTe液相外延材料组分分布的红外透射光谱评价技术

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.