Development of a parametric optical constant model for Hg1-xCdxTe for control of composition by spectroscopic ellipsometry during MBE growth
Development of a parametric optical constant model for Hg1-xCdxTe for control of composition by spectroscopic ellipsometry during MBE growth
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DOI：
10.1016/s0040-6090(97)00800-6
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发表时间：
1998-02-01
期刊：
影响因子：
2.1
通讯作者：
Benson, JD
中科院分区：
文献类型：
--
作者：
Johs, B;Herzinger, CM;Benson, JD
本文介绍了分子束外延生长过程中Hg_（1-x）Cd_xTe的光学常数随组分（x = 0-0.5）和温度（T=0-250 ℃）变化的关系，该关系适用于用椭圆偏振光谱法（SE）精确控制组分。首先提出了一种有效的方法，用于获取原位光学常数作为组合物和温度的函数。从这些原位测量中提取的光学常数，以及从室温值的文献数据，用于获得内部Kramers-Kronig一致的参数光学常数模型在离散的组合物和温度。然后，对温度“T”和组成“x”进行全局数据分析，其中光学常数模型的内部参数拟合为T和x的多项式。这个参数模型的开发，以取代，而不影响质量的椭偏数据拟合，通常的光学常数列表，同时使用一个合理的小的可调参数集。该模型足够灵活，可以描述半导体的复杂临界点结构，但又足够稳定，可以产生光学常数作为组成和温度的函数，并允许在测量范围外进行有限的外推。(C)1998年Elsevier Science S.A.
The development of an optical constant library for Hg1-xCdxTe as a function of composition (x = 0-0.5) and temperature (T=0-250 degrees C) which is suitable for precise composition control by spectroscopic ellipsometry (SE) during MBE growth is described. An efficient methodology for acquiring in situ optical constants as a function of composition and temperature is first presented. Optical constants extracted from these in situ measurements, as well as literature data from room temperature values, were used to obtain internally Kramers-Kronig consistent parametric optical constant models at discrete compositions and temperatures. Then a global data analysis over temperature 'T' and composition 'x' was performed in which the internal parameters of the optical constant model were fitted as polynomials in T and x. This parametric model was developed to replace, without compromising the quality of ellipsometric data fits, the usual tabulated optical constant lists while using a reasonably small set of adjustable parameters. The model is flexible enough to describe the complicated critical point structures of semiconductors, yet stable enough to generate optical constants as a function of composition and temperature and permit limited extrapolation outside the measured range. (C) 1998 Elsevier Science S.A.