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Single-event effects are a serious concern for high-speed III-V semiconductor devices operating in radiation-intense environments. GaAs integrated circuits (ICs) based on field effect transistor technology exhibit single-event upset sensitivity to protons and very low linear energy transfer (LET) particles. The current understanding of single-event effects in III-V circuits and devices, and approaches for mitigating their impact, are discussed.

Hall electron mobility in buried QW InGaAs channels, grown on InP substrates with HfO₂ gate oxide, is analyzed experimentally and theoretically as a function of top barrier thickness and composition, carrier density, and temperature. Temperature slope α in μ ~T^α dependence is changing from α=-1.1 to +1 with the reduction of the top barrier thickness indicating the dominant role of remote Coulomb scattering (RCS) in interface-related contribution to mobility degradation. Insertion of low-k SiO_x interface layer formed by oxidation of thin in-situ MBE grown amorphous Si passivation layer has been found to improve the channel mobility, but at the expense of increased EOT. This mobility improvement is also consistent with dominant role of RCS. We were able to a obtain a reasonable match between experiment and simple theory of the RCS assuming the density of charges at the high-k/barrier interface to be in the range of (2-4)×10¹³ cm^-2.

Insulated gate n-channel enhancement mode InGaAs field effect transistors with the GdScO₃ high-k dielectric have been fabricated and studied. The low frequency noise was high indicating a high interface density of traps. Trap density and its dependence on the gate voltage have been extracted from the noise and conductance measurements.

InGaAs high mobility transistors presently provide the fastest speeds. As InGaAs nonvolatile memory field effect transistors (NVMFETs) are scaled down past 22 nm gate width, threshold voltage variation becomes a limiting factor. Replacing the amorphous SiO₂ or HfO₂ with a heteroepitaxial barrier stack the threshold voltage can be stabilized by minimizing the interface charge at the barrier-channel interface. The floating gate is comprised of individually germanium-oxide cladded germanium quantum dots. The tunneling layer is comprised of a quantum well stack of ZnSe/ZnS/ZnMgSeTe/ZnS/ZnSe. The magnesium incorporation increases the the energy barrier but introduces dislocation that can leak charge. The ZnS and ZnSe layers have a lower bandgap but a lower dislocation density to assist with gate leakage prevention. We present simulation and experimental C-V data on InGaAs FET and II-VI tunneling layer on an InGaAs substrate respectively.

We have proposed and investigated In_yGa_1-yAs photoconductor grown by molecular-beam epitaxy on low-temperature step-graded metamorphic buffer. It exhibits superior bandwidth up to 6 THz and provides optical-to-terahertz conversion efficiency up to ~ 10⁻⁵ for rather low optical fluence ~ 40 μJ/cm². The intensity of THz generation for the given structure is two orders higher than for lowtemperature grown GaAs due substantial contribution of photo-Dember effect.

Terahertz (THz) oscillations in n${}^{+}$nn${}^{+}$ In${}_{0.53}$Ga${}_{0.47}$As diodes have been simulated with the use of a time-dependent hydrodynamic model. Under proper biased voltage and doping concentration, THz self-oscillations show up. The current self-oscillations originate from the formation and propagation of electric field domains in In${}_{0.53}$Ga${}_{0.47}$As diodes. The In${}_{0.53}$Ga${}_{0.47}$As device studied here may be presented as an excellent candidate as a solid-state THz source for monolithic integration.

The surface of materials plays an important role in their technological applications. In the interest to study the stability of materials and their behavior, we irradiate them by the electrons by using the electron spectroscopy such as the Auger electron spectroscopy (AES) and the electron energy loss spectroscopy (EELS). These methods have proved their good sensitivity to study material surfaces. In this paper, we give some results about the effect of the electron beam irradiating the compounds InP, InSb, InPO₄ and In_xGa_1-xAs. The III–V semiconductors InP and InSb seem to be sensitive to the electron irradiation. This breaks the chemical bonds between the element III and V which leads to an oxidation process at the surface. The AES and EELS spectroscopy are also used to characterize the oxide InPO₄ whose thickness is about 10 Å grown on the substrate InP(100). The irradiation of the system InPO₄/InP(100) by the electron beam of 5 keV energy leads to a structural change of the surface, so that there is breaking of chemical bonds between indium and phosphorus (In–P) and formation of new oxide other than InPO₄. In this study we show an important result concerning the effect of the electron beam on the compound In_xGa_1-xAs by varying the parameter x to obtain In_0.2Ga_0.8As and In_0.53Ga_0.47As. It appears that the electron beam affects In_0.2Ga_0.8As too much in comparison with In_0.53Ga_0.47As. In the case of the irradiation of In_0.2Ga_0.8As, there is breaking of chemical bonds between indium and GaAs leading to formation of indium oxide associated to GaAs.

Terahertz (THz) plasma oscillation in n⁺nn⁺ InGaAs vertical diodes is studied by using a numerical approach based on the hydrodynamic (HD) equations. The 1D HD model is coupled to 1D Poisson equation. We simulate the diode response to the optical excitation of plasma waves at room temperature. Our results clearly show the presence of 3D plasma resonances in the THz frequency domain. The selection of appropriately shaped optical excitation pulses helps in the realization of the detected frequency. The investigation is completed by introducing stochastic perturbations according to the Langevin equation.

We have proposed and investigated In_yGa_1-yAs photoconductor grown by molecular-beam epitaxy on low-temperature step-graded metamorphic buffer. It exhibits superior bandwidth up to 6 THz and provides optical-to-terahertz conversion efficiency up to ∼ 10⁻⁵ for rather low optical fluence ∼ 40 μJ/cm². The intensity of THz generation for the given structure is two orders higher than for low-temperature grown GaAs due substantial contribution of photo-Dember effect.