- Yu, S. and Tan, T.Y. and Gosele, U., Mechanism of Cr diffusion in GaAs,
Advanced III-V Compound Semiconductor Growth, Processing and Devices Symposium
pp. 747 - 58 .
(last updated on 2007/04/10)
Diffusion of substitutional Cr atoms (Crs) in GaAs results from the rapid migration of interstitial Cr atoms (Cri) and their subsequent changeover to occupy Ga sites (or vise versa), a typical substitutional-interstitial diffusion (SID) process. There are two possible ways for the Cri-Crs changeover to occur: the kick-out mechanism in which Ga self-interstitials are involved, and the dissociative mechanism in which Ga vacancies are involved. The Crs indiffusion profiles are of characteristic shapes indicating the dominance of the kick-out mechanism, while the Crs outdiffusion profiles are error-function shaped, indicating the dominance of the dissociative mechanism. In this study, an integrated SID mechanism, which takes into account the effects of both the kick-out and dissociative mechanisms, is used to analyze Cr diffusion results. Going beyond just qualitative consistency, the Cr in- and outdiffusion features in GaAs are explained on a quantitative basis. In this model the kick-out mechanism dominates Cr indiffusion while the dissociative mechanism dominates Cr outdiffusion. Parameters used to fit existing experimental results provided quantitative information on the Ga self-interstitial contribution to the Ga self-diffusion coefficient
chromium;diffusion in solids;dissociation;gallium arsenide;III-V semiconductors;interstitials;vacancies (crystal);