Growth experiment and analysis of buffer layer of high in content InGaAs films

High In content InGaAs films have important applications in the field of 2.1-2.4μm Infrared photodetector. In this paper, it has been obtained by Metal-Organic Chemical-Vapor Deposition (MOCVD) technique on 2-inch InP (100) substrates. Photoluminescence (PL) spectroscopy and HR-XRD spectrum have been employed to study the structural characteristics of InAlAs composite buffer layers and InGaAs epilayers. We found the 2.04μm PL peak in the sample, which is the result of photoluminescence of the high in content (≥65%) InGaAs film, we can reasonably suspect that the stress derived from the lattice mismatch has been effectively released by growing InAlAs composite buffer layers. The Reciprocal Space Method (RSM) is used for measuring the relaxation of InAlAs composite buffer layers. The results indicate that the InAlAs composite buffer structure with 3% step size can more effectively release the stress caused by lattice mismatch.