SIMS Study of Compositional Disordering in Si Ion Implanted AlGaAs?GaAs Superlattice

Compositional disordering in Si ion implanted AlGaAs–GaAs superlattices (SL's) has been studied by SIMS. It is found that Si diffuses fast when the Si concentration exceeds 3×1018 cm-3. The disordering of the SL's always occurs with this fast Si diffusion. It is suggested that the disordering of the SL's is induced by the substitutional exchange of (SiIII–SiV) pairs with the matrix vacancies. The Si diffusion in the SL layer is not enhanced by the presence of the GaAlAs/GaAs interface.