New Structure for Photoconductive Antennas Based on {LTG-GaAs/GaAs:Si} Superlattice on GaAs(111)A Substrate

摘要

The structural characteristics of a new structure for photoconductive antennas have been investigated. This structure is a multilayered epitaxial film grown on a GaAs(111)A substrate; it consists of alternating undoped low-temperature grown GaAs (LTG-GaAs) layers and GaAs layers synthesized in the standard high-temperature regime and doped with silicon (GaAs:Si). The As-4/Ga flow ratio is chosen such as to produce p-type GaAs:Si layers. LTG-GaAs layers were grown at an enlarged value. The samples grown on GaAs(100) substrates were single-crystal, whereas the single-crystal growth on GaAs(111)A substrates changed to polycrystalline when the film thickness reached 320-340 nm. The sizes of As precipitates in annealed samples, their distribution over the film thickness, and specific features of their crystal structure have been analyzed.