Column III-column V sublattice interaction via Zn and Si impurity-induced layer disordering of ¹³C-doped Al_xGa _1-xAs-GaAs superlattices

Experiments are described employing secondary-ion mass spectroscopy (SIMS) to study the stability of ¹³C-doped Al _0.5Ga_0.5As-GaAs superlattices against Zn and Si impurity-induced layer disordering (IILD). The modulation depth of the SIMS ²⁷Al and ¹³C signals is used as a sensitive probe of column III and column V sublattice interdiffusion. The data show that C_As is much more stable against Zn and Si IILD than the column III superlattice host crystal itself. The minor enhancement of C _As diffusion via the column III disordering agents, which is present to a significant extent for Si IILD but almost nonexistent for Zn IILD, suggests that there is no direct interchange of column III and column V sublattice atoms. The Zn and Si enhancement of carbon diffusion is probably caused by local Coulombic interaction between the diffusing Zn⁺_i and Si⁺_III species and the C^-_As acceptor.