Degradation characteristics of metal/Al2O3/n-InGaAs capacitors

Implementation of new materials in Metal-Oxide-Semiconductor stacks requires capabilities to predict long-time degradation as well as the impact of process changes on degradation processes. In this work, the degradation under constant voltage stress of metal gate/Al2O3/InGaAs stacks is studied for different pre-dielectric deposition treatments. The results show that the degradation, particularly under negative bias, is strongly affected by the oxide-semiconductor surface treatment of the samples. Two contributions (interface states and bulk traps) dominate depending on the stress conditions. Surface treatment with NH4OH shows a better quality of the interface in term of interface states; however, it contributes to generation of positive charge on the dielectric layer.Fil: Palumbo, Félix Roberto Mario. Technion - Israel Institute of Technology; Israel. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Inbar, Moshe. Technion - Israel Institute of Technology; Israel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Tests on the effectiveness of mass trapping by Eco-trap (Vyoril) in the control of Bactrocera oleae (Gmelin) in organic farming

Tests on the effectiveness of mass trapping by Eco-trap (Vyoril) in the control of Bactrocera oleae (Gmelin) in organic farming were carried out in 2003 and 2004. The tests took place into two organic olive groves located in Agrigento and Trapani (Sicily); in both years the olive cultivar was Cerasuola. In Agrigento, it was considered the effectiveness of Eco-trap vs. bottle traps baited with diammonium phosphate; while in Trapani the effectiveness of Eco-trap added to other products admitted in organic farming (two products containing kaolin and one containing copper) was evaluated. In 2003, year with a low B. oleae population density, no statistically significant difference resulted among Eco-trap, bottle traps with diammonium phosphate and control. In 2004 B. oleae infestations were high; although some statistically significant differences among plots with Eco-traps and plots without them emerged, the additional power of Eco-trap in controlling B. oleae resulted very limited in plots sprayed with kaolin products and more consistent in the plot with copper hydroxide. The economic advantage of the use of Eco-trap, also in comparison with repellent and antiovipositional products, still remains doubtful

Characteristics of stress-induced defects under positive bias in high-k/InGaAs stacks

The introduction of InGaAs as a channel material for complementary metal-oxide-semiconductor technology presents major challenges in terms of the characterization of the various defects that affect the performance and reliability. Understanding the generation of defects by constant voltage stresses is crucial in terms of their concentration profiles and energy levels. In particular, we want to understand the real nature of the defects responsible for the dispersion of C-V in strong accumulation. Here, we show that the degradation under positive bias of metal/Al2O3/n-InGaAs capacitors reveals two contributions depending on the temperature that affects the C-V curves in a different way. Based on features of stressed C-V curves, it is possible to estimate the onset point of the distribution of border traps near the midgap condition. The results suggest that these defects are strongly related to the characteristics of the InGaAs substrate.Fil: Palumbo, Félix Roberto Mario. Technion - Israel Institute of Technology; Israel. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Winter, R.. Technion - Israel Institute of Technology; IsraelFil: Krylov, I.. Technion - Israel Institute of Technology; IsraelFil: Eizenberg, M.. Technion - Israel Institute of Technology; Israe

Characteristics of the dynamics of breakdown filaments in Al2O3/InGaAs stacks

In this paper, the Al2O3/InGaAs interface was studied by X-ray photoelectron spectroscopy (XPS) after a breakdown (BD) event at positive bias applied to the gate contact. The dynamics of the BD event were studied by comparable XPS measurements with different current compliance levels during the BD event. The overall results show that indium atoms from the substrate move towards the oxide by an electro-migration process and oxidize upon arrival following a power law dependence on the current compliance of the BD event. Such a result reveals the physical feature of the breakdown characteristics of III-V based metal-oxide-semiconductor devices.Fil: Palumbo, Félix Roberto Mario. Comisión Nacional de Energía Atómica; Argentina. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Shekhter, P.. Technion - Israel Institute of Technology; IsraelFil: Cohen Weinfeld, K.. Technion - Israel Institute of Technology; IsraelFil: Eizenberg, M.. Technion - Israel Institute of Technology; Israe

Control of Bactrocera oleae and Ceratitis capitata in Organic Orchards: Use of Clays and Copper Products.

Tests on the effect of clays (kaolin and bentonite) and copper products (hydroxide and oxychloride) in the control of olive fruit fly, Bactrocera oleae (Rossi), and Mediterranean fruit fly, Ceratitis capitata (Wiedemann), were carried out from 2003 to 2006 in olive groves and in organic citrus orchards (satsuma, clementine, ‘Navelina’ orange). Results demonstrate an efficacy of kaolin products in reducing attacks of B. oleae on olives and those of C. capitata on citrus fruits; in olive groves the clays gave similar or better results than copper hydroxide. Bentonite AG/8W showed a significant reduction in punctures by C. capitata. Bentonite products and BPLK kaolin are washed off by rainfall more easily than Surround WP kaolin. In contrast to the effect of copper hydroxide on B. oleae in olive groves, no tested copper product showed a significant reduction in C. capitata punctures on citrus fruits. Clays are very useful tools to control tephritid and other insects and are also environmentally friendly, but currently, they are not permitted as products for plant protection in European and Swiss organic farming

Topological effective field theories for Dirac fermions from index theorem

Dirac fermions have a central role in high energy physics but it is well known that they emerge also as quasiparticles in several condensed matter systems supporting topological order. We present a general method for deriving the topological effective actions of (3+1) massless Dirac fermions living on general backgrounds and coupled with vector and axial-vector gauge fields. The first step of our strategy is standard (in the Hermitian case) and consists in connecting the determinants of Dirac operators with the corresponding analytical indices through the zeta-function regularization. Then, we introduce a suitable splitting of the heat kernel that naturally selects the purely topological part of the determinant (i.e. the topological effective action). This topological effective action is expressed in terms of gauge fields using the Atiyah-Singer index theorem which computes the analytical index in topological terms. The main new result of this paper is to provide a consistent extension of this method to the non Hermitian case where a well-defined determinant does not exist. Quantum systems supporting relativistic fermions can thus be topologically classified on the basis of their response to the presence of (external or emergent) gauge fields through the corresponding topological effective field theories.Comment: 7 pages, published versio

Modeling of the tunneling current in MOS devices after proton irradiation using a nonlinear series resistance correction

Contrary to what is expected for a damaged device, the impact of 10 MeV-energy protons on a metal-oxide-semiconductor (MOS) structure can give rise to a significant reduction of the gate tunneling current, mainly in the high bias range. In order to simulate the observed deviation, a correction to the oxide field in the Fowler-Nordheim tunneling expression is considered. Since the nature and location of the device damaged region have not been clearly identified yet, the conduction problem is circumvented by introducing an effective nonlinear series resistance correction. Experimental and simulated data obtained as a function of the irradiation fluences supporting the proposed approach are presented. The possible origin of this nonlinear resistance and its implications for the reliability assessment of irradiated MOS devices are also discussed.Fil: Palumbo, Félix Roberto Mario. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Constituyentes); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Miranda, Enrique. Universitat Autònoma de Barcelona; Españ