US – Page 417 – TechConnect Briefs

Study of Alloy Disorder in Quantum Dots through Multi-million Atom Simulations

Klimeck G., Oyafuso F., Boykin T.B., Bowen R.C., von Allmen P., NASA, Jet Propulsion Laboratory, US

A tight binding model which includes s, p, d and s* orbitals is used to examine the electronic structures of an ensemble of dome-shaped In0.6Ga0.4As quantum dots. Given ensembles of identically sized quantum dots, variations [...]

Process Modeling Based on Atomistic Understanding for State of the Art CMOS Device Design

Chakravarthi S., Diebel M., Chidambaram P.R., Ekbote S., Dunham S.T., Machala C.F., Johnson S., Texas Instruments, US

Atomistic modeling methods are emerging as a powerful tool to understand the physical behavior of complex systems. However, continuum process simulators are the core of state of the art TCAD simulators and substantial challenges must [...]

Variation of Contact Barrier Height in Metal-Semiconducting Carbon Nanotube Junctions using a Localized Gate

Gallo E., Nabet B., Freitag M., Johnson A.T., Drexel University, US

We have previously succeeded in modulating current in a carbon nanotube FET device due to the presence of a potential on an AFM tip. Symmetric I-V is observed with no tip, however, the tip has [...]

Effects of Backbone Disorder on Electronic Transport in DNA Molecules

Zhong J.X., Oak Ridge National Laboratory, US

A minimal model was recently proposed to explain the gap opening and the semi-conductor behavior in poly(G)-poly(C) DNA molecules. In this model, the large band gap is attributed to the hybridization of the G-G p [...]

Convergence Issues in Ab-initio Transport Calculation through Oxide Barriers and Molecules

Fonseca L.R.C., Demkov A.A., Motorola, Inc., US

Ab-initio calculations of transport through nanometer scale structures, such as individual atoms or molecules and ultra-thin oxide barriers directly link atomic structure and chemistry, which are difficult to probe, to transport properties, which are easier [...]

Finite Size Effects In Ferroelectric Nanosystems: Absence of mode softening

Wolpert D., Cox W., Cerne J., Markelz A., Zhao T., Ramesh R., University at Buffalo, US

Ferroelectrics are currently used for DRAM capacitors, nonvolatile memory elements, (FRAM), and switching and routing elements in optical communications systems. Further miniaturization and large scale application of these systems is limited by apparent finite size [...]

Zero Bias Anomalies in Electrochemically Fabricated Atomic-Scale Metal Junctions

Natelson D., Yu L.H., Rice University, US

Metallic nanojunctions (MNJ) are unique tools for examining electronic transport, correlations, quantum coherence, and disorder at the atomic scale. Extensive progress has been made in understanding clean MNJs fabricated in ultrahigh vacuum (UHV) by the [...]

Carrier Transit Time Optimization of a High Speed Bipolar Transistor Using Numerical Device Simulation

Loechelt G.H., Sellers J., Morgan J., Azam M., ON Semiconductor, US

The optimization of bipolar transistors for high speed applications requires knowing the trade-off between several competing factors, including emitter-base junction charging time, base transit time, base-collector capacitance, high injection degradation, and collector debiasing [1]. Numerical [...]

A Study on Growth of Ultrathin Silicon Dioxide Films by Rapid Thermal Oxidation

Zeng T., Doumanidis H.C., North Carolina State University, US

Silicon dioxide thin films are the basic components for microelectronics and other micro technologies. As the size of the transistors and relevant micro devices shrinks for faster and smaller chips and other microsystems, growth of [...]

Coupled Multiphysics Modeling of Semiconductor Lasers

Sikorski Z., Jiang Y., Czyszanowski T., Przekwas A., Turowski M., CFD Research Corporation, US

Comprehensive models of semiconductor lasers are required to predict realistic behavior of various laser devices for the spatially nonuniform gain that results due to current crowding. Nonuniform gain has visible effect on laser dynamics and [...]