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

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

Analytic expression for the Fowler-Nordheim V-I characteristic including the series resistance effect

It is shown in this communication that the Fowler-Nordheim (FN) tunneling expression for the current-voltage (I-V) characteristic can be analytically inverted so that an exact expression for the voltage-current (V-I) characteristic can be obtained. The solution of the resulting implicit equation is found using the Lambert W function, i.e. the solution of the transcendental equation wew = x. The reported expressions are supported by experimental I-V curves measured in thin (≈5 nm) SiO2 films in MOS capacitors. The analysis includes the case of a tunneling oxide with a large series resistance. For practical purposes, a closed-form expression for W based on a Padé-type approximation is also provided.Fil: Miranda, E.. Universitat Autònoma de Barcelona; EspañaFil: Palumbo, Félix Roberto Mario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Ezeiza; Argentin

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

Electrical correlation of double-diffused metaloxidesemiconductor transistors exposed to gamma photons, protons, and hot carriers

Double-diffused metaloxidesemiconductor n-channel power transistor devices were subjected to a high electric-field stress, gamma photons 60Co, and 10-MeV proton radiation, and were comparatively analyzed. The direct-current currentvoltage and high-frequency capacitancevoltage techniques were used to characterize the two different regions under the gate oxide in this kind of devices. The SiSiO2 interfaces at the channel side and at the drain side are characterized after thermal annealing. The correlation of the interface states with the trapped charge is a good quantitative tool to compare the effects from different degradation mechanisms. It is shown that, under given conditions, each kind of stress exhibits its own signature in the interface states versus the oxide charge plot.Fil: Palumbo, Félix Roberto Mario. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Faigon, Adrián Néstor. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Curro, Giuseppe. No especifíca

Model and fitting results for the filamentary conduction in MIM resistive switching devices

Experimental results for the resistive switching effect occurring in Pt/HfO2/Pt devices are analyzed within the framework of the two-terminal Landauer theory for mesoscopic conducting systems. It is shown that the magnitude of the current and the voltage dependence of the switching conduction characteristic are mainly dictated by the size of the filamentary path generated after electroforming. The temperature dependence of the high resistance conduction characteristics is also modeled in a consistent manner with the proposed picture.Fil: Palumbo, Félix Roberto Mario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Miranda, Enrique. Universitat Autònoma de Barcelona; EspañaFil: Ghibaudo, Gerard. Université Savoie Mont Blanc; FranciaFil: Jousseaume, V.. Université Savoie Mont Blanc; Franci

Influence of the spatial distribution of border traps in the capacitance frequency dispersion of Al2O3/InGaAs

In this paper, the capacitance frequency dispersion in strong accumulation of capacitance voltage curves has been studied for different high-k dielectric layers in MOS stacks. By studying experimental data at low (77 K) and room temperature (300 K), in oxides with different density of defects, it was possible reflect the spatial distribution of the defects in the capacitance frequency dispersion. The experimental data show that while at room temperature, the capacitance dispersion is dominated by the exchange of carriers from the semiconductor into oxide traps far away from the interface, at low temperature the oxide traps near the Al2O3/InGaAs interface are responsible for the frequency dispersion. The results indicate that the capacitance dispersion in strong accumulation reflect the spatial distribution of traps within the oxide, and that dielectric/semiconductor conduction band offset is a critical parameter for determining the capacitance dispersion for Al2O3/InGaAs based gate stacks.Fil: Palumbo, Félix Roberto Mario. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional; ArgentinaFil: Aguirre, Fernando Leonel. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Pazos, Sebastián Matías. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Krylov, Igor. Technion - Israel Institute of Technology; IsraelFil: Winter, Roy. Technion - Israel Institute of Technology; IsraelFil: Eizenberg, Moshe. Technion - Israel Institute of Technology; Israe

Hf-based high-k dielectrics for p-Ge MOS gate stacks

The physical and electrical properties of the gate stack high-k/Al2O3/GeO2/p-Ge were studied in detail, where the high-k is either HfO2 or alloyed HfO2 (HfZrOy, HfGdOx, or HfAlOx). Electrical measurements combined with x-ray photoelectron spectroscopy chemical bonding analysis and band alignment determination were conducted in order to assess the suitability of hafnium-based high-k for this kind of gate stacks, with emphasis on low density of interface states and border traps. HfAlOx was found to be the most promising high-k from those studied. The authors have also found that the current- voltage trends for the various systems studied can be explained by the band alignment of the samples obtained by our x-ray photoelectron spectroscopy analysis.Fil: Fadida, Sivan. Technion - Israel Institute of Technology; IsraelFil: Palumbo, Félix Roberto Mario. Technion - Israel Institute of Technology; Israel. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nyns, Laura. Imec; BélgicaFil: Lin, Dennis. Imec; BélgicaFil: Van Elshocht, Sven. Imec; BélgicaFil: Caymax, Matty. Imec; BélgicaFil: Eizenberg, Moshe. Technion - Israel Institute of Technology; Israe

Investigation of stress induced interface states in Al2O3/InGaAs metal-oxide-semiconductor capacitors

Implementation of high-k dielectrics on InGaAs for CMOS technology requires capabilities to predict long-time degradation and 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 n-type and p-type As2 passivated InGaAs substrates. The results show that the degradation for both positive bias and negative bias did not produce Al2O3 oxide traps, while the distribution of interface states increased. In particular, the distribution of interface states, calculated by the distributed impedance equivalent circuit model, increased significantly after positive bias stress regardless of the doping type of the substrate. The injection of carriers from the semiconductor conduction band into the gate dielectric enhanced the generation of interface states but not the generation of oxide traps, suggesting that the interfacial degradation is related primarily to the InGaAs surface and not to the oxide layer.Fil: Palumbo, Félix Roberto Mario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnologica Nacional; ArgentinaFil: Winter, R.. Technion - Israel Institute of Technology; IsraelFil: Tang, K.. University Of Stanford; Estados UnidosFil: McIntyre, P. C.. University Of Stanford; Estados UnidosFil: Eizenberg, M.. Technion - Israel Institute of Technology; Israe