The Effect of the Bi Precursors, (CH₃)₃Bi and (C₂H₅)₃Bi, on the Metal‐Organic Vapor Phase Epitaxy of GaAs_1‐yBi_y Films

Abstract

This study compares the effectiveness of two Bi sources, trimethyl bismuth (TMBi) and triethyl bismuth (TEBi), in the growth of GaAs 1-y Bi y thin films. Through optimization of the growth conditions, GaAs 1-y Bi y -GaAs heterostructures with high lateral homogeneity of Bi are grown. TEBi results in a lower carbon concentration than is typical of methyl-based compounds when used at low growth temperatures. These findings suggest the process of Bi incorporation proceeds more efficiently using the TEBi precursor. These studies do not show noticeable growth rate reduction under the dilute flows of TMBi and TEBi, however at high Bi source flux, a growth rate drop was observed for both sources.

Impact of in-situ annealing on dilute-bismide materials and its application to photovoltaics

“…The first 20 nm of the wells has an average Bi concentration of x¼ $0.031 while the upper 12 nm of the wells has an average Bi concentration of x¼ $0.042. Further investigation on the origin of the bilayer formation is needed although it is possibly related to the formation of a Bi surface reservoir and subsequent diffusion during the growth pauses at the interface between GaAs 1À x Bi x and GaAs [9,17]. The apparent increased Bi concentration in the wells closer to the surface arises from thickness variations across the TEM specimen.…”

“…1, using Pd-purified H 2 as a carrier gas at 76 T. The GaAs 1-x Bi x was grown by the simultaneous feed of triethyl gallium (TEGa), triethyl bismuth (TEBi), and tertiarybutyl arsine (TBAs) at the growth temperature of 380°C while the GaAs barriers were grown using TEGa and arsine (AsH 3 ) at the elevated temperature of 650°C after the GaAs 0.964 Bi 0.036 well growth was paused as summarized in Table 1. The effects of these specific precursors on the growth of GaAs 1À x Bi x were discussed elsewhere [9]. The growth interruption and temperature ramp-up are thought to evaporate the segregated Bi, which remains on the surface of bismide-containing well layer, as reported elsewhere [11,15].…”

“…Also, a complex bismuth distribution in a Bi-containing layer has been reported by Forghani et al as a result of the relatively long surface residence time of Bi precursors or the reaction products blocking surface sites for the adsorption and dissociation of the group III source [9]. We observe a complex Bi distribution within the relatively thick ($ 32 nm) GaAs 1 À x Bi x layers of the GaAs 1 À x Bi x /GaAs MQW by means of the transmission electron microscopy.…”

Enhanced Incorporation of P into Tensile-Strained GaAs1-yPyLayers Grown by Metal-Organic Vapor Phase Epitaxy at Very Low Temperatures

“…In general "low temperature" refers to growth temperatures considerably below a generally accepted optimal range for a specific material, for example ∼650 • C for MOVPE growth of GaAs. Low growth temperatures are often employed in the P184 ECS Journal of Solid State Science and Technology, 5 (3) P183-P189 (2016) growth of thermodynamically unstable alloys, such as the growth for GaAs 1-x Bi x 20 and GaAs 1-x Sb x , 21 in order to slow the kinetic processes on the growth front and impede the approach to thermodynamic equilibrium. High temperature growth of these alloys often leads to phase separation as predicted by the equilibrium phase diagrams.…”

Impact of thermal annealing on internal device parameters of GaAs 0.965 Bi 0.035 /GaAs 0.75 P 0.25 quantum well lasers

“…The metastable nature of the GaAs 1−x Bi x alloy, which exhibits a large miscibility gap [12], compels its epitaxial growth to be carried out under non-typical growth conditions involving very low growth temperature (around 400°C) and near-stoichiometric V/III flux ratio for molecular beam epitaxy (MBE) and gas-phase ratio for metal organic vapor phase epitaxy (MOVPE) [13,14]. However, the growth under the near-stoichiometric condition at such a low temperature can result in point defects and its associated defect complexes, which can act as non-radiative recombination centres within the materials [15].…”