Anomalous Coherent Bragg Rod Analysis Studies of GaAs/InGaAs

A considerable amount of work has been carried out recently in correlating growth conditions with electronically observed properties in Group III-V systems using a variety of characterization techniques. Ambiguity in interpretation of most characterization techniques arises due to difficulties in separating roughness effects from segregation and inter-diffusion of atomic species. We apply x-ray resonant techniques to the Coherent Bragg Rod Analysis (COBRA) phase retrieval procedure to produce high resolution electron density maps from bragg rod scans to determine with a high degree of accuracy, the relative concentrations of In and Ga in a system comprising of 1ML of GaAs on InGaAs.