Microstructural Characterization of InP Films on SOI (001) Substrates Grown by Selective Lateral Metal-Organic Vapor-Phase Epitaxy

• We report a microstructural characterization of InP films on SOI substrate grown by the lateral aspect ratio trapping method. • Large-area InP films without threading dislocations were obtained. • Typical InP films grown by this method contained planar defects that degrade crystal quality. • The mechanism of forming these defects is discussed. To achieve monolithic integration of Si-waveguide-coupled III-V laser diodes, it is important to establish a method of growing high-quality III-V materials on large Si wafers without a thick buffer layer. Here, the lateral aspect ratio trapping (LART) method has recently been attracting attention because of its potential for integrating large-area and high-quality III-V films on (001)-oriented silicon-on-insulator (SOI) substrates. In this paper, we report a detailed microstructural analysis of InP films that were fabricated on (001) SOI substrates by using metal–organic vapor-phase epitaxy and the LART method. The obtained films had an area of around 50 x 4 μm2, which is large enough for them to be used as templates in photonics device fabrication. Transmission electron microscopy revealed that propagation of threading dislocations in the Si/InP interface region was suppressed. However, the films tended to contain other planar defects, such as stacking faults, rotational twin boundaries, and anti- phase boundaries. We discuss the mechanisms underlying the generation of these defects and approaches to suppressing their formation.