Calculation of zinc diffusion profiles in in-based semiconductors by the finite-difference beam propagation method (FD-BPM)

Abstract

In this article we use the implicit finite-difference beam propagation method (implicit FD-BPM) to calculate acceptor density profiles created by the diffusion of Zn into InP, InGaAs, and InGaAsP. We verify the accuracy of this method by comparing our computed results with carrier density profiles measured by the C–V method, and discuss the advantages its use has over explicit differencing methods with regard to stability and computation time. Our calculations revealed a slight disagreement between the computed and experimental profiles, which we attributed to the neglect of unactivated Zn atoms; otherwise, the agreement between the profiles was quite good. Moreover, when we used our computed values to correct the acceptor density profile by taking into account these unactivated Zn atoms, we found that this slight disagreement between the acceptor density profile with no unactivated Zn atoms and the experimental carrier density profile was almost removed. Even when the number of time steps was large, our results clearly showed that the use of the implicit FD-BPM led to more stable solutions and shorter computation times than the use of explicit differencing methods. Our investigations clearly confirm the usefulness of the implicit finite-difference beam propagation method for computing Zn density profiles resulting from diffusion into semiconductors like InP. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 89(5): 33–42, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20194