Effects of antimony (Sb) incorporation on MOVPE grown InAs_yP_(1-y) metamorphic buffer layers on InP substrates

摘要

The effects of antimony incorporation and a convex compositional step-gradient on the surface morphology, defect generation, and defect propagation properties of InAs_yP_(1-y) metamorphic buffer layers (MBLs) were investigated. The incorporation of Sb reduces the root-mean-square (RMS) of the surface roughness, and complete elimination of the arsenic from the MBL (i.e. InP_zSb_(1-z)) leads to a reduction of RMS values of the surface roughness from 16 nm (InAs_yP_(1-y)) to 3.4 nm (InP_zSb_(1-z)), without noticeably altering the defect density in the upper layers of the MBL. InP_(1-x)Sb_x layers grown on an InP_zSb_(1-z) MBL have reduced hillock formation and exhibit energy bandgaps within 8% of that expected from theory.