A PHOTOLUMINESCENCE AND X-RAY-DIFFRACTION ANALYSIS OF INALAS INP HETEROSTRUCTURES GROWN BY MOLECULAR-BEAM EPITAXY/

Growth of In0.52Al0.48As epilayers on InP(100) substrates by molecular beam epitaxy at a wide range of substrate temperatures (470-550 degre es C) and at arsenic beam equivalent pressures which are higher than p reviously reported (D.F. Welch et al,, Appl. Phys. Lett., 46 (1985) 16 9), is carried out. A strong dependence of the photoluminescence (PL) and X-ray diffraction (XRD) linewidths and XRD intensity ratio (Int(ep i)/Int(sub)) on the substrate temperature was observed. The lattice mi smatch was the lowest when the growth was carried out at substrate tem peratures of 500-520 degrees C. The XRD diffraction peaks of samples g rown at low temperatures are comprised of smaller peaks suggesting an effect of disordering owing to the presence of alloy clustering. PL li newidth as low as 14 meV was recorded in samples grown at a V/III flux ratio as high as 160. The lattice mismatch in samples grown at high f lux ratios was found to be insensitive to changes in the V/III flux ra tios.