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A compact model for a phase-change memory cell is presented and confirmed by measurement. The model reproduces the non-linear current-voltage behavior of both set and reset states. The temperature-dependent crystallization and amorphization of the phase-change layer are taken into account in order to express resistance changes between set and reset states. The heat of fusion is also taken into account in the calculation of the amorphization.

For SiO pMOSFETs, the reaction diffusion model is well used to describe the NBTI degradation theoretically and the Ogawa model for hole trap generation is known exper imentally. However, there is not a good model of NBTI degradation for SiON devices. In this paper, we propose a nitrogen dependent hole trap generation model by extending these two models and present the NBTI degradation model for SiON pMOSFETs.

The confined states in ultra-thin Ge layers on oxide are investigated using three different state-of-the-art full-band methods. Contrary to the prediction of the simple effective mass approximation (EMA) and multiband-models that decoupled the Conduction Bands (CB) and the Valence Bands (VB), full-band calculations predicts much lower subband energy shifts due to quantum confinement.

In this work, we show full-band calculations of the tunneling properties of ZrO and HfO high- oxides. First, we have determined semiempirical tight-binding (TB) parameters which reproduce ab-initio band dispersions of the high- oxides; then we have calculated transmission coefficients and tunneling currents for Si/ZrO/Si and Si/HfO/Si MOS structures. Results show a very low gate leakage current in comparison to SiO-based structures with the same equivalent oxide thickness. The complex band structures of ZrO and HfO have been calculated; based on them we develop an energy dependent effective tunneling mass model. It is shown that this model can be used to obtain effective mass tunneling currents close to full-band results.

We conduct a thorough investigation of the tunneling dynamics of oxide traps in a-SiO, in particular of the E center, the E center, their hydrogenated counterparts, and the H atom. Based on these findings their behavior in the context of tunneling can be deduced. It is found that an E center can exchange electrons with the Si bulk. The E center shows two distinct behaviors induced by a spread in its tunneling levels. The H atom is not affected by the presence of an interface, whereas a H bridge may occur in every charge state.

The electrostatics of InSb double-gate MOSFETs is simulated using a self-consistent solver which calculates channel bandstructure and carrier population by tight-binding (TB) approach. The characteristic and the Quantum Confinement Stark Effect (QCSE) are evaluated. By comparing with the results from the method and effective mass approach, we show that full-band approach based on TB becomes more desirable when the channel is scaled down to a low dimensional quantum well. As the consequence of narrow channel width it is observed that the density of states (DOS) near band edges is decreased.

The effect of point defects such as oxygen vacancy and carbon interstitial on both electronic and structural characteristics of hafnium dioxide was analyzed by a quantum chemical molecular dynamics method. When a carbon atom as the impurity is introduced in hafnium dioxide, carbon impurity states (donor and acceptor) are formed in the band gap of hafnium dioxide. The band gap calculated from the energy difference between the donor and acceptor decreases to 1.6 eV. We conclude therefore, it is very important to control the composition of HfO films in order to assure the electronic performance and reliability of hafnium dioxide film.

Science and technology at the nanoscale size offer today fundamental challenges in the field of device modeling. In this paper we document the growing interest of academies, institutions, and industries and the present impact on the market, and discuss different design strategies that have been proposed and/or implemented, aimed at the practical realization of innovative nanodevices. Few main examples of ideas and devices, namely ion-channel nano-biosensors, biomimetic sensors, molecular devices, solid-state components for quantum computation, nanotube electronics, and non-volatile nanomemo-ries, are also revised.

High density of interface traps at the SiC-SiO interface gives rise to lower mobilities and currents in SiC MOSFETs. Detailed investigations are performed to measure and characterize these interface traps using experimental and modeling methods [–]. Recent measurements of threshold voltage instabilities by fast I–V methods have shown that the SiC-SiO interface not only contains fast interface traps, but also slower near-interface and oxide traps [, ]. Steady state modeling and simulations cannot characterize the effects of each of these defects. We have hence developed a detailed time dependent modeling scheme for dynamic interface trap occupation, and incorporated it into our 2D transient device simulator. We use the transient modeling to separate out and individually characterize interface, near-interface and oxide traps in 4H-SiC MOS devices.

An electro-thermal, transient device simulation study of Silicon Carbide (SiC) power thyristors operating in a pulsed-power circuit at extremely high current density has been carried out within the drift-diffusion approximation and classical heat generation and transport theory using MEDICI* []. The convergence problems normally associated with Technology Computer-Aided Design (TCAD) simulations of SiC bipolar devices were overcome without artificially increasing the free carrier concentration by optical carrier generation, or by increasing the initial temperature (thermal carrier generation). The simulation results closely predict the actual operating conditions of the SiC thyristor in the pulsed-power circuit and are used to interpret the results of experimental failure limit studies []. It is shown that TCAD simulations can realistically predict the electrical and thermal properties of complex SiC bipolar semiconductor devices operating under fast transient, pulsed-power conditions.