Atmospheric-Pressure Metalorganic Vapor Phase Epitaxy of GaAsBi Alloy on GaAs Substrate

Abstract

AbstractThis chapter deals with mainly the growth and the structural and optical characteristics of GaAsBi alloys. Firstly, the growth and the structural characteristic of GaAsBi alloys grown on GaAs substrate by conventional metalorganic vapor phase epitaxy technique have been investigated in detail and described in section “MOVPE Growth and Characterization of GaAsBi.” Secondly, a novel method to epitaxy GaAsBi layer on (001) GaAs substrate is presented in section “Growth and Characterization of GaAsBi Alloy Under Alternated Bismuth Flows.” Thirdly, the effects of thermal annealing on GaAs1 − x Bi x alloys are described in section “Effects of Thermal Annealing on GaAs1 − x Bi x Alloys.” Trimethyl gallium, trimethyl bismuth (TMBi), and arsine were used as precursor sources. Growth parameters such as growth temperature, TMBi flow and V/III ratio were checked on a wide range. The growth was monitored in situ by laser reflectometry using a 632.8 nm beam. High-resolution X-ray diffraction, secondary ion mass spectroscopy, photoluminescence, and photoreflectance spectroscopy have been used to characterize the obtained GaAsBi layers. In analyzing the surface morphology, atomic force microscopy and scanning electron microscopy were used to qualify films properties. Result shows that the solid composition of GaBi content in the GaAs1 − x Bi x alloy reaches a maximum value of about 4 %. A significant redshift in the emission of GaAsBi of ~42 meV per percent Bi is observed. The surface shows a Bi island formation on all the samples. The density and size of these islands depend greatly on the growth conditions and growth method.KeywordsGaAs SubstrateReflectivity SignalGrown LayerMetalorganic Vapor Phase EpitaxyGaAs Buffer LayerThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.