Determination of composition distributions in InP/InGaAs/InP quantum-well structures by X-ray crystal truncation rod scattering and quantum levels

The distributions of As and Ga atoms in an InP/InGaAs/InP hetero-epitaxial layer were investigated on an atomic scale by X-ray CTR (crystal truncation rod) scattering. The relationship between PH3-purge time (after the InGaAs layer was constructed) and the distributions of As and Ga atoms was studied, In samples which were designed to have a 1 hll-thick InGaAs layer, Ga atoms were not confined to 1 hit (monolayer). The energy levels of the InGaAs well layers were calculated using the measured As and Ga distributions. In order to compare them with the calculated result, a photoluminescence (PL) measurement was conducted and the measured energy levels agreed well with the calculation. (C) 1998 Elsevier Science B.V. All rights reserved.