It was recalled that (Cd,Hg)Te epilayers that were grown by using metalorganic chemical vapor deposition could be doped by Cu out-diffusion from (Cd,Zn)Te substrates. The Cu content in the substrates was governed by the purity of the raw materials. The Cu diffusivity could be controlled by adjusting the Te precipitate density in the substrates. Growth on substrates with a high concentration of Te precipitates resulted in lightly doped (Cd,Hg)Te epilayers, whereas a high Cu concentration was found in (Cd,Hg)Te that had been grown on substrates with a lower concentration of Te precipitates. A mechanism was proposed in which Te precipitates were assumed to getter Cu during the post-growth cooling of (Cd,Zn)Te, and trap Cu in the substrates.

R.Korenstein, R.J.Olson, D.Lee, P.K.Liao, C.A.Castro: Journal of Electronic Materials, 1995, 24[5], 511-4