A review of direct metamorphic In x Ga1− x As and InP epilayers on GaAs substrates by MOCVD

This is a review of direct growing high-quality In x Ga1− x As or InP buffer layers on GaAs substrates by metal-organic chemical vapour deposition (MOCVD). This low-temperature growth method benefits the improvement of metamorphic device performance. A simple and novel method of directly depositing thin In x Ga1− x As or InP buffer layers (<1 µm) on GaAs substrates is presented, instead of the strained-layer superlattice, two-step, graded or CS (compliant substrates) methods, while maintaining low dislocation density, high crystal quality, uniform and mirror-like surfaces. For the direct growth technique of In x Ga1− x As on GaAs, we found that an excellent quality In0.54Ga0.46As buffer of r.m.s surface roughness of only 0.686 nm by AFM and FWHM of 925 arcsec by XRD can be obtained at a low growth temperature of 440°C with a constant Ga/Ingas partial pressure of 5. An MIS-like Schottky diode with Au/i-InGaAs/n+-GaAs structure is investigated to check the film quality. A distinguished I–V characteristic wi...