Surface characterization of epitaxial lateral overgrowth of InP on InP/GaAs substrate by MOCVD

摘要

Epitaxial lateral overgrowth (ELO) of InP on InP/GaAs substrates by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) was investigated. The lateral overgrowth InP layers were obtained on the SiO_2 masked InP seed layer, which was deposited on the (100) GaAs substrate by the two-step method. The surface characterization of overgrowth InP was dependent on the Ⅴ/Ⅲ ratio, the mask width and the growth time. When decreasing the Ⅴ/Ⅲ ratio or reducing the mask width respectively, the sidewalls "competition effect" was obviously observed. After a longer time, new (100)-like top surfaces were formatted because of the precursors migrating from the sidewall facets to the (100) top surfaces. The experimental findings will be explained by growth kinetics in conjunction with the different dominant source supply mechanism.