Transient behavior of Hg1−xCdxTe films deposited on (100) CdTe substrates by chemical vapor transport

The growth history of Hg_1−xCd_xTe films deposited on (100) CdTe substrates by chemical vapor transport (CVT) has been studied, for the first time, by using a transient growth technique. The observed morphological evolution of Hg_1−xCd_xTe films deposited at 545°C shows a transition behavior from three-dimensional (3D) islands to two-dimensional (2D) layer growth. The experimental results indicate that the so-called critical time needed for the above morphological transition is about lh under present experimental conditions. Based on the chemical bonding properties of Hg_1−xCd_xTe, and on the behavior of the morphological transition, the Stranski-Krastanov growth mode is suggested for the epitaxial growth system. The time dependence of the growth thickness, of the growth rate (R₁₀₀) along the 100] direction, and of the surface composition all reveal a transient behavior. These are related to the nature of the Hg_1-xCd_xTe/ (100)CdTe heterojunction and to the surface reactions. Comparison of the growth rates and of the total mass deposited as a function of time shows the relationship between epitaxial growth and mass flux of the Hg_1−xCd_xTe-HgI₂ chemical vapor transport system.