Recent studies have shown that Zn diffusion preferentially induces mixing (interdiffusion) of In and Ga in unstrained InGaAs/InP superlattices, with little diffusion of the anions. In the present study, a 3.1% lattice mismatch is accommodated in the mixed superlattice with no observable defects in layers on the order of the predicted critical layer thickness. At high concentrations, Zn resides preferentially in the InP layers in the form of Zn3P 2. In marked contrast to this behavior of Zn, Si diffusion is observed to cause comparable interdiffusion on the cation and anion sublattices within a narrow range of dopant concentration. This result is at odds with some recent mixing models and is consistent with a divacancy mixing mechanism.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)