研究目的
To analyze the structure of cadmium telluride (CdTe) films grown on silicon (Si) and cadmium mercury telluride (CdHgTe) substrates using ellipsometry, and to determine the necessity of a more complex model than the one-layer film model to accurately describe the films' optical properties and heterogeneity.
研究成果
The study concludes that the one-layer film model leads to significant distortion of optical constants spectra for CdTe films with thicknesses greater than 70 nm. A two-layer film model is necessary to accurately describe the films' structure, with an inner layer of bulk CdTe and an outer layer consisting of a mixture of CdTe, cavities, and oxide. The outer layer's composition varies with deposition time and film thickness.
研究不足
The study is limited by the accuracy of the ellipsometric measurements and the assumptions made in the two-layer model. The heterogeneity of the films and the presence of surface roughness may also affect the results. Future studies could focus on increasing the measurement accuracy and exploring more complex models.
1：Experimental Design and Method Selection:
Ellipsometric analysis was performed on CdTe films grown on Si and CdHgTe substrates using the 'hot-wall' epitaxy vacuum method. The study utilized both a simple one-layer film model and a more complex two-layer film model for data interpretation.
2：Sample Selection and Data Sources:
Films were grown on monocrystalline silicon plates and cadmium–mercury–telluride plates. Samples were prepared by washing in HF acid and acetone before loading into the setup.
3：List of Experimental Equipment and Materials:
The setup included a vacuum 'hot-wall' epitaxy system, LEF-3M-1 compensatory zero-ellipsometer, and a spectral photometric ellipsometer with mercury lamp radiation spectral lines.
4：Experimental Procedures and Operational Workflow:
Films were grown separately for fixed times (6, 10, and 14 minutes) to obtain different thicknesses. Ellipsometric measurements were performed at various wavelengths to determine the films' optical constants and thicknesses.
5：Data Analysis Methods:
The Method of Thickness Curves (MTC) and software package 'Ellipsometric calculator' were used for optical constants and film thickness estimation. The two-layer model was applied to account for film heterogeneity.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
