Selective MOCVD Growth of GaAs on Si Substrate with Superlattice Intermediate Layers

GaAs was grown on a Si substrate through a SiO2 mask using superlattice intermediate layers by MOCVD. Single and poly crystalline GaAs layers were grown on the Si substrate and on the mask, respectively. Ridge growth was observed at the substrate/mask interface. The relationship between the ridge growth properties (the shape and the height) and the growth conditions were made clear. The ridge growth rate increases exponentially with approaching the interface. The ridge shape was determined by the surface migration and the gradient in the gas phase concentration of the Ga active species. The ridge growth height of GaAs grown on GaAs was higher than that grown on Si. These results could be explained by taking account of the difference in the surface migration length of the Ga active species on GaAs and Si substrates.