Integrated atomistic process and device simulation of decananometre MOSFETs

In this paper we present a methodology for the integrated atomistic process and device simulation of decananometre MOSFETs. The atomistic process simulations were carried out using the kinetic Monte Carlo process simulator DADOS, which is now integrated into the Synopsys 3D process and device simulation suite Taurus. The device simulations were performed using the Glasgow 3D statistical atomistic simulator, which incorporates density gradient quantum corrections. The overall methodology is illustrated in the atomistic process and device simulation of a well behaved 35 nm physical gate length MOSFET reported by Toshiba

The relationship between corporate social responsibility and corporate financial performance: Evidence from a developing country

We investigate the relationship between corporate social responsibility (CSR) and corporate financial performance (CFP) in a developing country context using annual report data from a sample of 131 firms over a 5 year period (2008-2012). Legitimacy theory and stakeholder theory underpin the study. We find a positive and significant relationship between CSR and CFP when using accounting measures of return on assets and equity, but an insignificant relationship when using the market based Tobin’s Q. The moderating effect of organisational governance on measures of workplace and environmental reporting is found to be important in a less developed economy

2D-TCAD Simulation on Retention Time of Z2FET for DRAM Application

Traditional memory devices are facing more challenges due to continuous down-scaling. 6T-SRAM suffers from variability [1-2] and reliability [3-4] issues, which introduce cell stability problems. DRAM cells with one transistor, one capacitor (1T1C) struggle to maintain refresh time [5-6]. Efforts have been made to find new memory solutions, such as one transistor (1T) solutions [7-9]. Floating body based memory structures are among the potential candidates, but impact ionization or band-to-band tunnelling (B2BT) limits their refresh time [10]. A recently proposed zero impact ionization and zero subthreshold swing device named Z2FET [9, 11-12] has been demonstrated and is a promising candidate for 1T DRAM memory cell due to technology advantages such as CMOS technology compatibility, novel capacitor-less structure and sharp switching characteristics. In the Z2FET memory operation, refresh frequency is determined by data retention time. Previous research [11-12] is lacking systematic simulation analysis and understanding on the underlying mechanisms. In this paper, we propose a new simulation methodology to accurately extract retention time in Z2FET devices and understand its dependency on applied biases, temperatures and relevant physical mechanisms. Since the stored ‘1’ state in Z2FET is an equilibrium state [9, 11-12] and there is no need to refresh, we will concentrate on state ‘0’ retention. Two types of ‘0’ retention time: HOLD ‘0’ and READ ‘0’ retention time will be discussed separately

The dimerized phase of ionic Hubbard models

We derive an effective Hamiltonian for the ionic Hubbard model at half filling, extended to include nearest-neighbor repulsion. Using a spin-particle transformation, the effective model is mapped onto simple spin-1 models in two particular cases. Using another spin-particle transformation, a slightly modified model is mapped into an SU(3) antiferromagnetic Heisenberg model whose exact ground state is known to be spontaneously dimerized. From the effective models several properties of the dimerized phase are discussed, like ferroelectricity and fractional charge excitations. Using bosonization and recent developments in the theory of macroscopic polarization, we show that the polarization is proportional to the charge of the elementary excitations

Interaction between elevated co2 and organic matter on bacterial metabolismo

Aquatic Sciences Meeting (Aquatic Sciences: Global And Regional Perspectives - North Meets South), 22-27 February 2015, Granada, Spain.Microcosm experiments to assess bacterioplankton response to autochthonous inputs of organic matter modified by future acidified ocean conditions were performed. Surface seawater enriched with inorganic nutrients and incubated in UVR-transparent cubitainers was bubbled for 8 days with regular air (380 ppmv CO2) or with a high CO2-air mixture (1000 ppmv CO2) to be used as inocula. In the second phase of the experiment, natural bacterioplankton communities enriched with the acidified or non-acidified organic matter inocula were incubated under dark conditions during 8 days in the presence or absence of CO2 as previously. Bacterial abundance, production and viability were measured as physiological indicators of bacterial metabolism. The results showed that acidified organic matter produced higher abundances for similar production rates early during the incubation, while non-acidified organic matter produced higher bacterial production and viability latter at the end of the experiment, indicating a more recalcitrant character of the organic matter under these conditions. We demonstrate that CO2 effects on bacterioplankton are mainly due to indirect effects on organic matter characteristics rather than to direct effects of acidification on bacteria metabolism.N

Experimental and Simulation Study of a High Current 1D Silicon Nanowire Transistor Using Heavily Doped Channels

Silicon nanowires have numerous potential applications, including transistors, memories, photovoltaics, biosensors and qubits [1]. Fabricating a nanowire with the required characteristics for a specific application, however, poses some challenges. For example, a major challenge is that, as the transistors dimensions are reduced, it is difficult to maintain a low off-current (Ioff) whilst simultaneously maintaining a high on-current (Ion). Some sources of this parasitic leakage current include quantum mechanical tunnelling, short channel effects and statistical variability [2, 3]. A variety of new architectures, including ultra-thin silicon-on-insulator (SOI), double gate, FinFETs, tri-gate, junctionless and gate all-around (GAA) nanowire transistors, have therefore been developed to improve the electrostatic control of the conducting channel. This is essential since a low Ioff implies low static power dissipation and it will therefore improve power management in the multi-billion transistors circuits employed globally in microprocessors, sensors and memories

Multi-stakeholder Innovation Platforms and knowledge management: Africa RISING science, innovations and technologies with scaling potential from the Ethiopian Highlands

United States Agency for International Developmen

Charge dynamics in the Mott insulating phase of the ionic Hubbard model

We extend to charge and bond operators the transformation that maps the ionic Hubbard model at half filling onto an effective spin Hamiltonian. Using these operators we calculate the amplitude of the charge density wave in different dimensions. In one dimension, the charge-charge correlations at large distance d decay as 1/(d^3 ln^{3/2}d), in spite of the presence of a charge gap, as a consequence of remaining charge-spin coupling. Bond-bond correlations decay as (-1)^d 1/(d ln^{3/2}d) as in the usual Hubbard model.Comment: 4 pages, no figures, submitted to Phys. Rev. B printing errors corrected and some clarifications adde