Modeling the diffusion of Be in InGaAs/InGaAsP epitaxial heterostructures under non-equilibrium point defect conditions

摘要

Be diffusion from 0.2 #mu#m Be doped (3 * 10~(19) cm~(-3)) In_(0.53)Ga_(0.47)As layer sandwiched between 0.5 #mu#m undoped In_(0.73)Ga_(0.27)As_(0.58)P_(0.42) layers, grown by GSMBE has been studied. The samples were subjected to RTA in temperature range from 700 deg C to 900 deg C with time durations of 10-240 s. SIMS was employed for a quantitative determination of the Be depth profiles. Two kick-out models of substitutional-interstitial diffusion have been considered. To explain the obtained experimental results, the kick-out model, involving neutral Be interstitial species and singly positively charged Ga or In self-interstitials is proposed. The built-in electric field, bulk self-interstitial generation/annihilation, the Fermi-level and extended defect formation effects were taken into account in the simulations.