Data were presented which showed that low-temperature (680C) Zn diffusion was effective in reducing the dislocation density of epitaxial GaAs which was grown onto Si. The GaAs/Si system was analyzed by using both cross-sectional and plan-view transmission electron microscopy. Simple thermal annealing of GaAs/Si at a higher temperature (850C) was also studied. The reduction in dislocation density which occurred due to Zn diffusion was suggested to arise from the increased concentrations of point defects which were generated during Zn diffusion. This resulted in enhanced dislocation climb. The mechanism was consistent with impurity-induced layer disordering, via Zn diffusion, in AlGaAs/GaAs heterostructures.

D.G.Deppe, N.Holonyak, K.C.Hsieh, D.W.Nam, W.E.Plano, R.J.Matyi, H.Shichijo: Applied Physics Letters, 1988, 52[21], 1812-4