Shrinking limits of silicon MOSFET's: Numerical study of 10-nm-scale devices

We have performed numerical modeling of dual-gate ballistic n-MOSFET's with channel length of the order of 10 nm, including the effects of quantum tunneling along the channel and through the gate oxide. Our analysis includes a self-consistent solution of the full (two-dimensional) electrostatic problem, with account of electric field penetration into the heavily-doped electrodes. The results show that transistors with channel length as small as 8 nm can exhibit either a transconductance up to 4,000 mS/mm or gate modulation of current by more than 8 orders of magnitude, depending on the gate oxide thickness. These characteristics make the devices satisfactory for logic and memory applications, respectively, though their gate threshold voltage is rather sensitive to nanometer-scale variations in the channel length.Comment: 8 pages, 10 figures. Submitted to Special Issue of Superlattices and Microstructures: Third NASA Workshop on Device Modeling, August 199

Terahertz Response of Field-Effect Transistors in Saturation Regime

We report on the broadband THz response of InGaAs/GaAs HEMTs operating at 1.63 THz and room temperature deep in the saturation regime. We demonstrate that responses show linear increase with drain-to-source voltage (or drain bias current) and reach very high values up to 170V/W. We also develop a phenomenological theory valid both in the ohmic and in the saturation regimes.Comment: 11 pages, 3 figure

Closed-form 2D modeling of sub-100 nm MOSFETs in the subthreshold regime, Journal of Telecommunications and Information Technology, 2004, nr 1

Closed-form 2D modeling of deep-submicron and sub-100 nm MOSFETs is explored using a conformal mapping technique where the 2D Poisson equation in the depletion regions is separated into a 1D long-channel case and a 2D Laplace equation. The 1D solution defines the boundary potential values for the Laplacian, which in turn provides a 2D correction of the channel potential. The model has been tested for classical MOSFETs with gate lengths in the range 200{250 nm, and for a super-steep retrograde MOSFET with a gate length of 70 nm. With a minimal parameter set, the present modeling reproduces both qualitatively and qualitatively the experimental data obtained for such devices

Electrostatic phase separation: a review

The current understanding and developments in the electrostatic phase separation are reviewed. The literature covers predominantly two immiscible and inter-dispersed liquids following the last review on the topic some 15 years. Electrocoalescence kinetics and governing parameters, such as the applied field, liquid properties, drop shape and flow, are considered. The unfavorable effects, such as chain formation and partial coalescence, are discussed in detail. Moreover, the prospects of microfluidics platforms, non-uniform fields, coalescence on the dielectric surfaces to enhance the electrocoalescence rate are also considered. In addition to the electrocoalescence in water-in-oil emulsions the research in oil-in-oil coalescence is also discussed. Finally the studies in electrocoalescer development and commercial devices are also surveyed. The analysis of the literature reveals that the use of pulsed DC and AC electric fields is preferred over constant DC fields for efficient coalescence; but the selection of the optimum field frequency a priori is still not possible and requires further research. Some recent studies have helped to clarify important aspects of the process such as partial coalescence and drop–drop non-coalescence. On the other hand, some key phenomena such as thin film breakup and chain formation are still unclear. Some designs of inline electrocoalescers have recently been proposed; however with limited success: the inadequate knowledge of the underlying physics still prevents this technology from leaving the realm of empiricism and fully developing in one based on rigorous scientific methodology

Working with different methods for students with neuropathic disability in mathematical education

Målet med denna kunskapsöversikt har varit att undersöka vad forskning beskriver om hur matematiklärare bör gå tillväga, för att arbeta med elever som har någon form av funktionsvariation. Det resultat vi har fått fram visar dock att det inte finns en enkel väg, utan det finns olika metoder inom ämnet matematik. Men de flesta källor tog upp vikten av inventioners påverkan samt att eleverna själva ska utvärdera sitt arbete under matematiklektionerna. Slutsatsen är att läraren behöver individanpassa och med hjälp av de olika metoderna enklare stötta eleverna med särskilda behov inom matematiken, utifrån de metoder som kunskapsöversikten tagit upp från olika forskare. Men något vi även konstaterar i diskussionen är att det inte finns ordentligt med underlag för att säkerställa att dessa metoder som nämnts är bra eller dåliga, detta då den största studien behandlade 50 elever. Därav efterfrågas större studier i området så man kan med säkerhet slå fast på om dessa metoder är bra eller dåliga

Closed-form 2D modeling of sub-100 nm MOSFETs in the subthreshold regime

Closed-form 2D modeling of deep-submicron and sub-100 nm MOSFETs is explored using a conformal mapping technique where the 2D Poisson equation in the depletion regions is separated into a 1D long-channel case and a 2D Laplace equation. The 1D solution defines the boundary potential values for the Laplacian, which in turn provides a 2D correction of the channel potential. The model has been tested for classical MOSFETs with gate lengths in the range 200-250 nm, and for a super-steep retrograde MOSFET with a gate length of 70 nm. With a minimal parameter set, the present modeling reproduces both qualitatively and quantitatively the experimental data obtained for such devices