A MODEL OF THE INTERDIFFUSED MULTILAYER PROCESS

The interdiffused multilayer process (IMP) is a novel approach to grow ing Hg1-xCdxTe. In this process, alternating thin films of HgTe and Cd Te are grown and allowed to interdiffuse resulting in a bulk material of constant composition. A model of the IMP must include the effects o f both the deposition of new material and the interdiffusion of the ma terial. It must also be able handle the flush phases of the IMP where the growth rate decays to zero. Existing approaches to modeling epitax ial growth of Hg1-xCdxTe treat growth and interdiffusion as separate, sequential steps resulting in numerical stability problems, pseudodiff usion effects, or flush phase modeling problems. The model presented h ere, however, is based on an incremental balance where growth and diff usion occur simultaneously, resulting in a model exhibiting none of th e difficulties mentioned above. The IMP growth model is integrated wit h a model for calculating reflectance from a laser directed at near no rmal incidence angle. The predicted reflectance is compared to experim ental measurements and showed a good preliminary fit when the model em ployed default parameters. The agreement is greatly improved after par ameter fitting.