Development of Hierarchical Simulation Framework for Design and Optimization of Molecular Based Flash Cell

The field of molecular electronics continues to spur interest in the quest for miniaturization and reduction of operational power of electron devices. Most of the systems described in the literature are based on organic molecules, such as benzene, ferrocene and fullerenes [1]. However, the use of inorganic molecules known as polyoxometalates (POMs) (see Fig. 1 and Fig. 2) could offer several important advantages over the conventional and organic based devices. The interest in POMs for flash cell applications stems from the fact that POMs are highly redox active molecules and that they can also be doped with electronically active heteroatoms [3]. They can undergo multiple reversible reductions/oxidations, which makes them attractive candidates for multi-bit storage in flash memory cells. Our recent work showed that POMs are more compatible with existing CMOS processes than organic molecules and they can replace the polysilicon floating gate in contemporary flash cell devices [2]. In this work, we discuss a further improvement and development of our simulation framework and models, e.g. Poisson distribution of the molecules in the oxide, introducing a various device geometry such as FDSOI and nanowires and improved simulation flow

Commission on the Loose? Delegated Lawmaking and Comitology after Lisbon

The Treaty of Lisbon has altered the institutional mechanism of the European Union. The introduction of formal hierarchy of legal acts has important implications for the balance of power among the EU institutions. This paper argues that the Commission is likely to enjoy some discretion in delegated lawmaking while remaining in the shadow of the legislators’ activism. The Commission has also successfully positioned itself to diminish the influence of comitology committees on the adoption of implementing acts, though a new layer of complexity was added. The possible outcomes of this new institutional battle are analysed in the context of the new challenges to the Community method. Some important inferences of this institutional shift for the debate on the democratic deficit in the EU are also drawn up

3D Multi-Subband Ensemble Monte Carlo Simulator of FinFETs and nanowire transistors

In this paper we present the development of a 3D Multi Subband Ensemble Monte Carlo (3DMSB-EMC) tool targeting the simulation of nanoscaled FinFETs and nanowire transistors. In order to deliver computational efficiency, we have developed a self-consistent framework that couples a MSB- EMC transport engine for a 1D electron gas with a 3DPoisson- 2DSchro ̈dinger solver. Here we use a FinFET with a physical channel length of 15nm as an example to demonstrate the appli- cability and highlight the benefits of the simulation framework. A comparison of the 3DMSB-EMC with Non-Equilibrium Green’s Functions (NEGFs) in the ballistic limit is used to verify and validate our approach

Random Discrete Dopant Induced Variability in Negative Capacitance Transistors

In this work we investigate the impact of random discrete dopants (RDD) induced statistical variability in ferroelectric negative capacitance field effect transistors (NCFETs). We couple the 3D `atomistic' statistical device simulator GARAND with the Landau - Khalatnikov equation of the ferroelectric for this study. We found that the negative capacitance effect provided by the ferroelectric layer can lead to suppression of the RDD induced variability in the threshold voltage (Vt), OFF-current (IOFF), and ON-current (ION). This immunity to RDD induced variability increases with increase in the ferroelectric thickness

First Principle Simulations of Electronic and Optical Properties of a Hydrogen Terminated Diamond Doped by a Molybdenum Oxide Molecule

In this work we investigate the surface transfer doping process induced between a hydrogen-terminated (100) diamond and a metal oxide MoO 3 , using the Density Functional Theory (DFT) method. DFT allows us to calculate the electronic and optical properties of the hydrogen-terminated diamond (H-diamond) and establish a link between the underlying electronic structure and the charge transfer between the oxide materials and the H-diamond. Our results show that the metal oxide molecule can be described as an electron acceptor and extracts the electrons from the diamond creating 2D hole gas in the diamond surface. Hence, this metal oxide molecule acts as a p-type doping material for the diamond

Участие на Република България в процедурите по комитология – нови отговорности

In this study an attempt will be made to outline the historical development of the legal regulation towards the comitology procedures in the Republic of Bulgaria, analyzing the strengths and weaknesses of the legislative framework. In addition, some results from the practice of participation of representatives of the Bulgarian public administration in the proceedings of the comitology committees will be summarized.Vihar Georgiev is a doctoral student at the Department of European Studies, Sofi a University /Bulgaria/. In his research he focuses on the procedures refered to as ‘comitology’. e-mail: [email protected] Вихър Георгиев е докторант в катедра „Европеистика“ на СУ „Св.Климент Охридски“. Основният фокус на неговите изследвания са процедурите за осъществяване на изпълнителните правомощия на Европейската комисия e-mail: [email protected]

Simulation study of surface transfer doping of hydrogenated diamond by MoO₃ and V₂O₅ metal oxides

In this work, we investigate the surface transfer doping process that is induced between hydrogen-terminated (100) diamond and the metal oxides, MoO₃ and V₂O₅, through simulation using a semi-empirical Density Functional Theory (DFT) method. DFT was used to calculate the band structure and charge transfer process between these oxide materials and hydrogen terminated diamond. Analysis of the band structures, density of states, Mulliken charges, adsorption energies and position of the Valence Band Minima (VBM) and Conduction Band Minima (CBM) energy levels shows that both oxides act as electron acceptors and inject holes into the diamond structure. Hence, those metal oxides can be described as p-type doping materials for the diamond. Additionally, our work suggests that by depositing appropriate metal oxides in an oxygen rich atmosphere or using metal oxides with high stochiometric ration between oxygen and metal atoms could lead to an increase of the charge transfer between the diamond and oxide, leading to enhanced surface transfer doping

Electronic and Optical Properties of Hydrogen-Terminated Diamond Doped by Molybdenum Oxide: A Density Functional Theory Study

In this work we investigate the surface transfer doping process induced between a hydrogen-terminated (100) diamond and a metal oxide MoO 3 , using the Density Functional Theory (DFT) method. Using DFT, we have calculated the electronic and optical properties of the hydrogen-terminated diamond and established a link between the underlying electronic structure and the charge transfer between the oxide materials and the hydrogen-terminated diamond. Our results show that the metal oxide can be described as an electron acceptor and extracts the electrons from the diamond creating 2D hole gas in the diamond surface. Hence, this metal oxide acts as a p-type doping material for the diamond

Self-consistent physical modeling of SiOx-based RRAM structures

We apply a unique three-dimensional (3D) physics-based atomistic simulator to study silicon-rich (SiOx, x<;2) resistive switching nonvolatile memory (RRAM) devices. We couple self-consistently a simulation of ion and electron transport to the `atomistic' simulator GARAND and a self-heating model to explore the switching processes in these structures. The simulation model is more advanced than other available phenomenological models based on the resistor breaker network. The simulator is calibrated with experimental data, and reconstructs accurately the formation and rupture of the conductive filament in the 3D space. We demonstrate how the simulator is useful for exploring the little-known physics of these promising devices, and show that switching is an intrinsic property of the SiOx layer. In general, the simulation framework is useful for providing efficient designs, in terms of performance, variability and reliability, for memory devices and circuits. The simulator validity is not limited to SiOx-based devices, and can be used to study other promising RRAM systems based, e.g., on transition metal oxides

3D Multi-Subband Ensemble Monte Carlo Simulator of FinFETs and nanowire transistors

In this paper we present the development of a 3D Multi Subband Ensemble Monte Carlo (3DMSB-EMC) tool targeting the simulation of nanoscaled FinFETs and nanowire transistors. In order to deliver computational efficiency, we have developed a self-consistent framework that couples a MSB- EMC transport engine for a 1D electron gas with a 3DPoisson- 2DSchro ̈dinger solver. Here we use a FinFET with a physical channel length of 15nm as an example to demonstrate the appli- cability and highlight the benefits of the simulation framework. A comparison of the 3DMSB-EMC with Non-Equilibrium Green’s Functions (NEGFs) in the ballistic limit is used to verify and validate our approach