A paper in the Feb. issue of IEEE TED

A Physically Based Accurate Model for Quantum Mechanical Correction to the Surface Potential of Nanoscale MOSFETs Karim, M. A.   Haque, A.   Department of Electrical and Electronic Engineering, United International University, Dhaka; This paper appears in: Electron Devices, IEEE Transactions on Publication Date: Feb. 2010 Volume: 57,  Issue: 2 On page(s): 496-502 ISSN: 0018-9383 Digital Object Identifier: 10.1109/TED.2009.2037453 First Published: 2009-12-28 Current Version Published: 2010-01-19

Abstract We present a physically based explicit analytical model for the quantum mechanical (QM) correction to the surface potential of nanoscale metal–oxide–semiconductor (MOS) devices. The effect of wave function penetration into the gate dielectric is taken into account. Instead of using the band-gap widening approach, which indirectly includes QM correction, the proposed correction term is directly added to the semiclassical surface potential. Under accumulation bias, charges in extended states and quantized states contribute to the surface potential in different ways. The proposed QM correction considers this difference in contributions. Comparison with two existing analytical QM correction models and two self-consistent QM numerical models show that the proposed correction is more accurate than the existing analytical models. The improvement achieved under the accumulation bias is particularly significant. The gate $C$– $V$ characteristics of a number of different MOS devices have been simulated using the proposed correction. Excellent agreement with published experimental data has been observed.

Analog FastSpice RF delivers noise analysis for RF circuits

By Rick Nelson, Editor-in-Chief -- EDN, 12/22/2009

Berkeley Design Automation Inc has announced AFS RF (Analog FastSpice radio frequency), which Chief Operating Officer Paul Estrada calls the industry’s first true Spice-accurate noise-analysis tool for RF circuits. AFS RF accurately analyzes nanometer-scale device noise impact for all types of prelayout and postlayout circuits, ensuring early insight into its impact on performance, power, and area.
 Before the emergence of AFS RF, designers had to use limited-spectrum RF tools that can only approximate device noise impact on RF circuits, Estrada explains. Such approximations are increasingly inaccurate with decreasing process geometries, often becoming grossly inaccurate in nanometer-scale circuits. Circuits with sharp transitions, such as switched-capacitor filters, charge pumps, and dividers; high-frequency circuits, such as RF front-end blocks; and oscillators are especially sensitive to these inaccuracies. Without accurate analysis, designers must include expensive design margin or risk missing specifications in silicon.
 Using the industry’s first full-spectrum device-noise-analysis engine, Analog FastSpice RF provides true Spice accuracy for every run. For complex circuits, it is five to 10 times faster than traditional RF tools that can only approximate device-noise effects. AFS RF features the DNA (device noise-analysis) Advisor to characterize DNA requirements, high-capacity periodic-steady-state analysis for greater than 100,000-element postlayout circuits, full-spectrum periodic-noise analysis with true Spice accuracy, full-spectrum total oscillator-device-noise analysis capability with phase and amplitude noise, and harmonic balance for fast single-tone analysis of moderately nonlinear circuits.


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