Impact of oxygen plasma postoxidation process on Al 2 O 3 / n -In 0.53 Ga 0.47 As metal-oxide-semiconductor capacitors

International audienceCapacitance-voltage (C-V) measurements and x-ray photoelectron spectroscopy (XPS) analysis were performed in order to investigate the effect of a oxygen (O2) plasma after oxide deposition on the Al2O3/n-In0.53Ga0.47As metal-oxide-semiconductor structure passivated with ammonia NH4OH solution. From C-V measurements, an improvement of charge control is observed using the O2 plasma postoxidation process on In0.53Ga0.47As, while the minimum of interface trap density remains at a good value lower than 1 × 1012 cm−2 eV−1. From XPS measurements, we found that NH4OH passivation removes drastically the Ga and As native oxides on the In0.53Ga0.47As surface and the O2 plasma postoxidation process enables the reduction of interface re-oxidation after post deposition annealing (PDA) of the oxide. The advanced hypothesis is the formation of interfacial barrier between Al2O3 and In0.53Ga0.47As which prevents the diffusion of oxygen species into the semiconductor surface during PDA

Improvement of interfacial properties of Al2O3/GaSb using O2 plasma postoxidation process

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Study of the oxidation at the Al2O3 / GaSb interface after NH4OH and HCl / (NH4)2S passivations and O2 plasma post atomic layer deposition process

International audienceIn this work, the Al2O3/GaSb interface has been studied by x-ray photoelectron spectroscopy in order to improve interfacial and electrical properties of metal–oxide–semiconductor structures based on GaSb. First, different passivations using NH4OH or (NH4)2S were studied with a dilution of 4% and 5%, respectively, in order to reduce native oxides on the GaSb surface. Then, we considered the oxidation of the Al2O3 and GaSb surface after treatments with an oxygen (O2) plasma post atomic layer deposition (ALD) process and with post deposition annealing at different temperatures. We found that (NH4)2S passivation leads to a lower quantity of native oxides on the GaSb surface and that the O2 plasma post ALD process enables the formation of an oxygen-rich layer within the Al2O3 at the interface reducing the GaSb surface oxidation after post deposition annealing of the oxide

Effect of the choice of the terminal boar on fattening, carcass performances and meat quality

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Monte Carlo analysis of III–V PIN diodes for tunnel-FETs and Impact Ionization-MOSFETs

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Monte Carlo model for the analysis and development of III-V Tunnel-FETs and Impact Ionization-MOSFETs

International audienceImpact-ionization metal-oxide-semiconductor FETs (I-MOSFETs) are in competition with tunnel FETs (TFETs) in order to achieve the best behaviour for low power logic circuits. Concretely, III-V I-MOSFETs are being explored as promising devices due to the proper reliability, since the impact ionization events happen away from the gate oxide, and the high cutoff frequency, due to high electron mobility. To facilitate the design process from the physical point of view, a Monte Carlo (MC) model which includes both impact ionization and band-to-band tunnel is presented. Two ungated InGaAs and InAlAs/InGaAs 100 nm PIN diodes have been simulated. In both devices, the tunnel processes are more frequent than impact ionizations, so that they are found to be appropriate for TFET structures and not for I- MOSFETs. According to our simulations, other narrow bandgap candidates for the III-V heterostructure, such as InAs or GaSb, and/or PININ structures must be considered for a correct I-MOSFET design

Solvation Effects on Self-association and Segregation Processes in tert-Butanol - Aprotic Solvent Binary Mixtures

International audienceThe present study reveals that the fully miscible binary mixtures consisting of tert-butanol with aprotic solvents form well-defined ordered supermolecular structures, which have been characterized on different lengthscales. Three different types of microstructures have been determined. They are separated by distinct crossovers that appear as a function of the dilution rate, going from "correlated clusters" to "diluted clusters" and "diluted monomers" microstructures. These observations have been made possible by the combination of Raman vibration spectroscopy, 1H NMR , and neutron diffraction that probe respectively the cluster formation (self-association) and the inter-cluster correlations (clusters segregation). The solvation effects on both the cluster formation and the inter-cluster correlations have been assessed by tuning the alcohol-solvent interaction i.e. changing the chemical nature of the diluting solvent from a purely inert alkane to a weakly interacting aromatic system

Characterization of defect states in Mg-doped GaN-on-Si p + n diodes using deep-level transient Fourier spectroscopy

International audienceMg-doped GaN-on-Si p + n diodes have been fabricated and characterized by static electrical and deep-level transient Fourier spectroscopy (DLTFS) measurements. From static capacitance-voltage (C-V) and current-voltage (I-V) characteristics, we estimated the diffusion barrier of the p + n diode close to the GaN band gap at room temperature. The temperature dependence of the capacitance showed freeze-out effect of the Mg-dopants at 200 K. From DLTFS measurements for various reverse bias and pulse voltages, two peaks were found and are composed of different defect states. The first peak with two components was related to diffusion of Mg p-type dopants in the n-GaN and V N-related defects. The two components have activation energies close to 0.25 eV, from valence band and conduction band with a capture cross-section of ∼10 −16 cm 2. The second peak with two components showed temperature shifts with the pulse height indicating a band-like behavior. This peak was commonly attributed to deep acceptor C N-related defects with an activation energy of E V +0.88 eV and a capture cross-section of 10 −13 cm 2. A second acceptor level was found, with an activation energy of 0.70 eV and a capture cross-section of 10 −15 cm 2. This second component was previously attributed to native point defects in GaN

Improvement of interfacial and electrical properties of Al 2 O 3 / n-Ga 0.47 In 0.53 As for III-V impact ionization MOSFETs

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