Selective metalorganic vapor phase epitaxial growth of InGaAsP / InP layers with bandgap energy control in InGaAs / InGaAsP multiple-quantum well structures

Abstract

Selective metalorganic vapor phase epitaxial growth on a mask-patterned planar InP substrate is studied. For direct applications to active layers and passive waveguide layers in photonic devices, InGaAsP/InP layers are selectively grown on typically 2 μm wide open stripe regions between pairs of SiO 2 mask stripes. For such relatively narrow growth regions, layer thicknesses are enhanced not only by group III species that are laterally diffused in the gas phase, but also by the species that migrate from surfaces of side facets to the top surface. A flat grown surface is obtained by decreasing the amounts of the surface migrated species, which results in an increase of migration lengths on the top surfaces. Selectively grown InGaAs/InGaAsP multiple-quantum well (MQW) ridge structures with crystallographically smooth side facets and flat interfacesare successfully obtained. By changing the mask stripe width, the bandgap energy of the MQW structure is modified. Group III composition change of selectively grown InGaAs layers, which occurs in both of the gas phase diffusion and the surface migration processes, results in an additional bandgap energy shift in thickness-modulated InGaAs quantum wells. A peak wavelength shift as large as 200 nm is obtained from photoluminescence spectra of simultaneously grown MQW ridge structures, while maintaining flat interfaces.