Experiments are described employing secondary‐ion mass spectroscopy (SIMS) to study the stability of13C‐doped Al0.5Ga0.5As‐GaAs superlattices against Zn and Si impurity‐induced layer disordering (IILD). The modulation depth of the SIMS27Al and13C signals is used as a sensitive probe of column III and column V sublattice interdiffusion. The data show that CAsis much more stable against Zn and Si IILD than the column III superlattice host crystal itself. The minor enhancement of CAsdiffusion 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+iand Si+IIIspecies and the C−Asacceptor.