High-quality GaAs on sawtooth-patterned Si substrates

Abstract
We report a novel technique for growing GaAs on Si substrates with a low density of threading dislocations. The process involves patterning a 200 nm period sawtooth grating on (100) Si using a combination of holographic lithography and wet chemical etching. The GaAs layers grown by metalorganic chemical vapor deposition on such substrates exhibit a dramatic reduction in the density of threading misfit dislocations, even when the grown layers are thin. Twins and stacking faults are also reduced dramatically by either in situ thermal‐cycle growth or ex situ rapid thermal annealing.