Random dopant induced threshold voltage lowering and fluctuations in sub-0.1 μm MOSFET's: A 3-D 'atomistic' simulation study

Asenov, A. (1998) Random dopant induced threshold voltage lowering and fluctuations in sub-0.1 μm MOSFET's: A 3-D 'atomistic' simulation study. IEEE Transactions on Electron Devices, 45(12), pp. 2502-2513. (doi: 10.1109/16.735728)

Abstract

A three-dimensional (3-D) 'atomistic' simulation study of random dopant induced threshold voltage lowering and fluctuations in sub-0.1 μm MOSFETs is presented. For the first time a systematic analysis of random dopant effects down to an individual dopant level was carried out in 3-D on a scale sufficient to provide quantitative statistical predictions. Efficient algorithms based on a single multigrid solution of the Poisson equation followed by the solution of a simplified current continuity equation are used in the simulations. The effects of various MOSFET design parameters, including the channel length and width, oxide thickness and channel doping, on the threshold voltage lowering and fluctuations are studied using typical samples of 200 atomistically different MOSFETs. The atomistic results for the threshold voltage fluctuations were compared with two analytical models based on dopant number fluctuations. Although the analytical models predict the general trends in the threshold voltage fluctuations, they fail to describe quantitatively the magnitude of the fluctuations. The distribution of the atomistically calculated threshold voltage and its correlation with the number of dopants in the channel of the MOSFETs was analyzed based on a sample of 2500 microscopically different devices. The detailed analysis shows that the threshold voltage fluctuations are determined not only by the fluctuation in the dopant number, but also in the dopant position

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Asenov, Professor Asen
• Authors: Asenov, A.
• Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Research Group: Device Modelling Group
• Journal Name: IEEE Transactions on Electron Devices
• Publisher: Institute of Electrical and Electronics Engineers
• ISSN: 0018-9383
• Copyright Holders: Copyright © 1998 Institute of Electrical and Electronics Engineers
• First Published: First published in IEEE Transactions on Electron Devices 45(12):2502-2513
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher