Dynamics of arsenic diffusion in metalorganic chemical deposited HgCdTe on GaAs/Si substrates

This paper describes the behavior of arsenic when diffused from an ion implanted source in Hg1−xCdxTe (x≂0.19–0.23) grown by metalorganic chemical vapor deposition (MOCVD) on GaAs/Si substrates. The results are compared with the diffusion of arsenic from a grown source in the material. Diffusion mechanisms of arsenic were studied from chemical analysis (secondary ion mass spectroscopy) and theoretical modeling, combined with techniques for radiation damage study [transmission electron microscopy (TEM)] for revealing the defect structure of material [chemical defect etching‐etch pit density (EPD), TEM], and for electrical junction determination (electron beam induced current). The main experimental observation was that arsenic redistributes during thermal anneal by a multicomponent mechanism in which the tail‐components differ depending on the EPD of the material. We propose a model that explains the four components observed: (1) a surface retarded diffusion component; (2) an atomic vacancy‐based component...