Simulation of p‐type diffusion in compound semiconductor: the case of beryllium implanted in InGaAs

Abstract

A system of equations describing transient enhanced diffusion of beryllium in InGaAs due to kick‐out mechanism or due to formation, migration, and dissociation of the pairs “beryllium atom–group III self‐interstitial” is proposed and analyzed. Simulation of coupled diffusion of beryllium atoms and self‐interstitials in InGaAs during rapid thermal annealing was done for the case of dual implantation. For the experiment under consideration the first ion implantation of phosphorus atoms produced the region of extended defects that led to “uphill” diffusion of implanted Be in the defect region and in the vicinity of the surface. The suggested reason of “uphill” diffusion could be related to the nonuniform distribution of group III self‐interstitials that was formed due to the absorption of point defects on the extended defects and on the surface of a semiconductor. The calculated dopant profile agreed well with the experimental one and a comparison with the experimental data resulted in obtaining the values of beryllium diffusivity and other parameters describing Be diffusion in InGaAs. Further improvements of the model are also discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)