Examination of the zinc diffusion in InP and InGaAs(P), as well as across InGaAs(P)-InP heterostructures

The examination of the diffusion of zinc, out of the gaseous phase, in InP and InGaAs(P), using a Zn3P2 or ZnAs2 source, is presented. Two semiclosed processes are used. For one, a thermal, neutral, reusable quartz ampule was used as a diffusion container. For the other one, using a graphite diffusion container, heating and cooling times were reached within ten seconds. Thus, the diffusion depth could be exactly controlled. Processes for cleaning the semiconductor, and observations on zinc diffusion were discussed. A simple rule for the determination of the diffusion time depending on the InGaAs(P) layer thickness and on the diffusion depth required, was derived. A particular model was set up for describing the diffusion across a heterostructure. Thanks to a simulation process, the model was checked out using the experimental results for diffusion across a single heterostructure and across three heterostructures.