Reduction of threading dislocations by InGaAs interlayer in GaAs layers grown on Si substrates

Abstract

High-quality GaAs epilayers with dislocation densities of 1.2×106 cm−2 on (100)Si substrates have been obtained by insertion of an InGaAs strained interlayer combined with thermal cycle annealing instead of strained layer superlattices. All the layers were grown by low-pressure metalorganic vapor phase epitaxy. The threading dislocation density near the surface of 4 μm thick GaAs was measured by plan-view transmission electron microscopy. The threading dislocation density was found to be very sensitive to the In composition of the interlayer and the specifics of thermal cycle annealing.