Computationally efficient quantum-mechanical technique to calculate direct tunnelling gate leakage current in metal-oxide-semiconductor structures

We propose a computationally efficient, accurate and numerically stable quantum- mechanical technique to calculate the direct tunneling (DT)gate current in metal-oxide-semiconductor (MOS) structures. Knowledge of the imaginary part G of the complex eigenenergy of the quasi-bound inversion layer states is required to estimate the lifetimes of these states. Exploiting the numerically obtained exponential dependence of G on the thickness of the gate-dielectric layer even in the sub-1-nm-thickness regime, we have simplified the determination of G in devices where it is too small to be calculated directly. It is also shown that the MOS electrostatics, calculated self-consistently with open boundary conditions, is independent of the dielectric layer tickness provided that the other parameters remain unchanged. Utilizing these findings, a computationally efficient and numerically stable method is developed for calculating the tunneling current–gate voltage characteristics. The validity of the proposed model is demonstrated by comparing simulation results with experimental data. Sample calculations for MOS transistors with high-K gate-dielectric materials are also presented. This model is particularly suitable for DT current calculation in devices with thicker gate dielectrics and in device or process characterization from the tunneling current measurement

Accurate modeling of gate capacitance in deep submicron MOSFETs with high-K gate-dielectrics

Gate capacitance of metal-oxide-semiconductor devices with ultra-thin high-K gate-dielectric materials is calculated taking into account the penetration of wave functions into the gate-dielectric. When penetration effects are neglected, the gate capacitance is independent of the dielectric material for a given equivalent oxide thickness (EOT). Our selfconsistent numerical results show that in the presence of wave function penetration, even for the same EOT, gate capacitance depends on the gate-dielectric material. Calculated gate capacitance is higher for materials with lower conduction band offsets with silicon. We have investigated the effects of substrate doping density on the relative error in gate capacitance due to neglecting wave function penetration. It is found that the error decreases with increasing doping density. We also show that accurate calculation of the gate capacitance including wave function penetration is not critically dependent on the value of the electron effective mass in the gate-dielectric region

Three-loop HTLpt thermodynamics at finite temperature and chemical potential

In this proceedings we present a state-of-the-art method of calculating thermodynamic potential at finite temperature and finite chemical potential, using Hard Thermal Loop perturbation theory (HTLpt) up to next-to-next-leading-order (NNLO). The resulting thermodynamic potential enables us to evaluate different thermodynamic quantities including pressure and various quark number susceptibilities (QNS). Comparison between our analytic results for those thermodynamic quantities with the available lattice data shows a good agreement.Comment: 5 pages, 6 figures, conference proceedings of XXI DAE-BRNS HEP Symposium, IIT Guwahati, December 2014; to appear in 'Springer Proceedings in Physics Series

Representations of swine flu: Perspectives from a Malaysian pig farm

© The Author(s), 2010. This is the author's accepted manuscript. The final published article is available from the link below.Novel influenza viruses are seen, internationally, as posing considerable health challenges, but public responses to such viruses are often rooted in cultural representations of disease and risk. However, little research has been conducted in locations associated with the origin of a pandemic. We examined representations and risk perceptions associated with swine flu amongst 120 Malaysian pig farmers. Thirty-seven per cent of respondents felt at particular risk of infection, two-thirds were somewhat or very concerned about being infected. Those respondents who were the most anxious believed particular societal “out-groups” (homosexuals, the homeless and prostitutes) to be at higher infection risk. Although few (4%) reported direct discrimination, 46% claimed friends had avoided them since the swine flu outbreak. Findings are discussed in the context of evolutionary, social representations and terror management theories of response to pandemic threat

Experimental investigations in epitaxial growth of crystalline layers final report

Epitaxial growth of crystalline layer

Fluctuating initial condition and smoothening effect on elliptic and triangular flow

In heavy ion collisions, event-by-event fluctuations in participating nucleon positions can lead to triangular flow. Generally, one uses Monte-Carlo Glauber model to obtain the participating nucleon positions. To use in a hydrodynamic model, the positions needs to be smoothened. We study the effect of smoothening of Glauber Monte-Carlo initial conditions on elliptic and triangular flow. It is shown that integrated as well as differential elliptic and triangular flow remain largely unaltered, irrespective of functional form of the smoothening function, or the smoothening parameterComment: 4 pages, 4 figure

Microscale application of column theory for high resolution force and displacement sensing

We present the design, fabrication and experimental validation of a novel device that exploits the amplification of displacement and attenuation of structural stiffness in the post-buckling deformation of slender columns to obtain pico-Newton force and nanometer displacement resolution even under an optical microscope. The extremely small size, purely mechanical sensing scheme and vacuum compatibility of the instrument makes it compatible with existing visualization tools of nanotechnology. The instrument has a wide variety of potential applications ranging from electro-mechanical characterization of one dimensional solids to single biological cells

The prevalence of occult hepatitis B virus (hbv) infection in a large multi-ethnic haemodialysis cohort.

Haemodialysis patients are at increased risk of exposure to blood borne viruses. To reduce transmission in the UK, all haemodialysis patients are regularly screened, and if susceptible to Hepatitis B virus (HBV) infection, vaccinated