Structural Properties of {LTG-GaAs/GaAs:Si} Superlattices on GaAs(100) and (111)A Substrates

Abstract—A new structure for photoconductive antennas is proposed, which represents a multilayer epitaxial film grown on a GaAs(111)A substrate and consisting of alternating low-temperature grown undoped GaAs (LTG-GaAs) layers and GaAs layers formed in the standard high-temperature mode and doped with silicon (GaAs:Si). The As₄ and Ga flow ratio γ is chosen such that the GaAs:Si layers have p-type conductivity. The LTG-GaAs layers are grown at a high γ value. A similar structure is grown on a (100) substrate as a reference. The structural properties of the samples are investigated: the phase composition is explored by high-resolution X-ray diffractometry; the surface relief, by atomic-force microscopy, and the Si-impurity thickness distribution, by secondary-ion mass spectrometry.