Interdiffusion in mercury cadmium telluride evaluated from vapor phase growth kinetics

A method is presented for determining interdiffusion coefficients from the kinetics of isothermal vapor phase epitaxial growth of mercury cadmium telluride (Hg1-xCdxTe). After an initial transient, growth is interdiffusion limited. Interdiffusion coefficients in the composition range x = 0.1 to 0.7 and a temperature range of 450 to 700 0C are determined using a simple geometric analysis of the composition profiles obtained in this interdiffusion limited regime. The technique offers advantages in simplicity and added control over the defect nature of the material during the interdiffusion process. The interdiffusion coefficients for the composition and temperature range studied are represented by the following equation: Dx(cm2/s) = 300 exp(-7.53x) exp (-1.92 eV/kT). Comparison with other studies shows good agreement. (author)