Finite element thermal analysis on the crystal growth of HgCdTe by the travelling heater method

Abstract

A finite element quasi-steady-state thermal model is described to simulate the growth of (Hg,Cd)Te by the traveling heater method. The ampoule region is incorporated in the thermal model and forms the basis for comparing the simulation results with experimental measurements. Sensitivity studies were carried out to explore the change of interface shape due to variations in thermophysical parameters, physical dimensions of the system, thermal boundary profile, and crystal growth conditions. It is found that the interface shape is always concave at the solvent/crystal/quartz-wall three-phase contact point regardless whether the macroscopic interface shape is concave or convex. This local concavity is due to the higher quartz-wall thermal conductivity with respect to that of the growing crystal. The modeling interface shapes are in good agreement with experimental observations and with the aid of the model simulation to search for the appropriate thermal and thermodynamic conditions, slightly macroscopic convex interface shapes can be achieved and (Hg,Cd)Te single crystals were grown.