EUROCORES_FONE 1. Call_Device Electronics Based on Nanowires and Nanotubes (DEWINT)

Critical building blocks for emerging nanotechnologies such as carbon nanotubes (CNTs) and silicon nanowires (Si NWs) are test-beds of fundamental concepts relating dimensionality and size with physical properties. Since predictable and controllable conductance is critical to electronic applications, the understanding and characterization of electronic transport and noise in such 1D structures is technologically important. The goal of this project is to carry out an integrated experimental and theoretical investigation of transport and noise in electronic devices based on carbon nanotubes and silicon nanowires. Partners of this joint project are IEIIT-CNR (I), TU Vienna (A), De Montfort University (UK), and Cambridge University (UK). The partners from UK will fabricate individually contacted, gated CNTs and Si NWs and measure their electrical characteristics and noise properties from room temperature down to liquid Helium temperature. In the Individual Project of TU Vienna a numerical simulation tool is developed in order to address transport in realistic structures based on nanowires and nanotubes. For CNTs, a quantum transport module based on the non-equilibrium Green`s functionformalism including scattering processes is developed. For Si NW devices a subband Monte Carlo method in connection with tunneling models for the contacts is used to describe transport in the 1D electron gas. The device and circuit simulator MINIMOS-NT is enhanced to enable the simulation of nanowire and nanotube-based devices. The transport equations for the 1DEG are solved self-consistently with the three-dimensional Poisson equation, enabling the simulation of complex, three-dimensional geometries. Modeling is carried out for contacts, phonon spectrum, electron-phonon interaction, and defects. The simulation model is tested against nanotube and nanowire FETs fabricated and characterized by the project partners in UK. Simulations are used to aid physical parameter extraction. CNTs and Si NWs have been studied in recent years as potential alternatives to CMOS devices. TU Vienna studies figures of merit, such as on-to-off current ratio and high frequency characteristics, using MINIMOS-NT. Performance of nanowire and nanotube FETs are assessed in comparison with other FET architectures in the scaling limit, including multi-gate FETs.