Synchrotron X-ray topography and electrical characterization of epitaxial GaAs p–i–n structures

Results from synchrotron X-ray topography and electrical characterization of thick epitaxial GaAs p–i–n structures suitable for manufacturing of radiation detectors are reported. The structures under study have been grown with hydride vapor phase epitaxy method. A comprehensive set of large-area transmission, large-area back-reflection and transmission section topographs are analyzed. The X-ray topography results are compared with the dark current density of the detector diodes. The X-ray topographs show the defect structure in the samples and provide important information for epitaxial process optimization.