Defect reduction in the large lattice mismatched system of GaSb on GaAs, ∼7%, was accomplished using full wafer block copolymer (BCP) lithography. A self-assembled BCP mask layer was used to generate a hexagonal pattern of ∼20nm holes on ∼40nm centers in a 20nm SiO2 layer. GaSb growth initially takes place selectively within these holes leading to a dense array of small, strain-relaxed epitaxial GaSb islands. The GaSb grown on the patterned SiO2 layer exhibited a reduction in the X-ray linewidth attributed to a decrease in the threading dislocation density when compared to blanket pseudomorphic film growth.

Defect Reduction in Epitaxial GaSb Grown on Nanopatterned GaAs Substrates using Full Wafer Block Copolymer Lithography. S.Jha, C.C.Liu, T.S.Kuan, S.E.Babcock, P.F.Nealey, J.H.Park, L.J.Mawst, T.F.Kuech: Applied Physics Letters, 2009, 95[6], 062104