Characterization of InGaAs/InP Epitaxial Layers Grown Over V-Groove Patterned InP Substrates using Gas Source Molecular Beam Epitaxy

Gas source molecular beam epitaxy has been used to deposit single InP layers, and multiple layers of InGaAs/InP over V-groove patterned (100) InP substrates. The V-grooves were defined by the (211)A and (111)B family of crystal planes. Scanning electron microscopy, transmission electron microscopy, and scanning photoluminescence were used to characterize the variation in the composition and thickness of the epitaxial layers. Defect-free epitaxial layers were achieved within (211)A V-grooves; whereas, dislocations were observed in the InGaAs layers deposited within (111)B grooves. The dislocations are attributed to the large lattice mismatch caused by a variation in composition due to differential GroupIII diffusion on the groove sidewalls. Scanning photoluminescence indicates an In (100) diffusion length of 2.2–3.5µm.