Antiphase Boundary Free InP Microridges on (001) Silicon by Selective Area Heteroepitaxy

Heteroepitaxy of III–V compound semiconductors on silicon (Si) or silicon-on-insulator (SOI) substrates is of great interest for photonics and electronics applications. In this work, antiphase-boundary (APB)-free indium phosphide (InP) microridges have been selectively grown by metal–organic chemical vapor deposition (MOCVD) on patterned (001) SOI substrates with an extremely low fill factor of 0.5%. By reduction of the exposed (001) plane of the micropatterned Si substrate surface using anisotropic potassium hydroxide (KOH) etching, as well as optimization of the growth temperature of the InP buffer, APBs can be completely eliminated, yielding an atomically flat InP (001) surface. Without any further defect filtering techniques applied, the surface defect density for the InP microridges is 1.3 × 108 cm–2 on the basis of X-ray diffraction (XRD) and cross-sectional scanning transmission electron microscopy (STEM) measurements. Multiple thin indium gallium arsenide (InGaAs) growth markers were inserted in the InP buffer to understand the growth evolution and the effect of defects on the InP surface morphology. The study presented provides a promising path for truly monolithic integration of III–V active devices on Si substrates.