Quantitative analysis of composition profiles in quantum well structures using grazing incidence X-ray reflectivity and photoluminescence

A new quantitative analysis method using grazing incidence x-ray reflectivity (GIXR) and photoluminescence (PL) simultaneously (GIXR/PL method), was applied for the first time to obtain the composition profile from an InAs_xP_1-x/InP single quantum well (SQW) structure. By assuming a Gaussian distribution, the characteristic As carryover length and the total As amount could be quantitatively determined. The As distributions obtained after a PH₃ purge were also analyzed by the GIXR/PL method. After a 10 second PH₃ purge the total amount of As was reduced from 5.13 monolayers to 2.56 monolayers but its carryover length into InP capping layer was almost constant at about 6 monolayers irrespective of the interruption time. The rate constant for the As re-desorption process in a PH₃ ambient was calculated as 0.067 s^-1 assuming a first order reaction model