Nanotech 2001 Vol. 1
Nanotech 2001 Vol. 1
Technical Proceedings of the 2001 International Conference on Modeling and Simulation of Microsystems

Semiconductor Device Modeling and Novel Structures Simulation Chapter 10

Improved Modified Local Density Approximation for Modeling of Size Quantization in NMOSFETs

Authors: C. Jungemann, C.D. Nguyen, B. Neinhüs, S. Decker and B. Meinerzhagen

Affilation: Universitat Bremen, Germany

Pages: 458 - 461

Keywords: MOS devices, quantization effects, inversion layer

An improved version of the modified local density approximation is presented which correctly describes the impact of size quantization on the threshold voltage and capacitance of state-of-the-art NMOSFETs with very thin oxides for temperatures from 200K to 500K and for doping concentrations up to 5.10E18/cm3 in the channel area. The model which modifies the conduction band edge close to the Si/SiO-interface is ideally suited for device modeling (e.g.: drift-diffusion, hydrodynamic), because it depends only on the local doping concentration, the local lattice temperature and the distance from the interface and not on solution variables of the numerical model like the electrostatic potential or the carrier densities. Therefore, device simulations with the new model are in most cases as efficient and robust as those based on the classical approximation ignoring quantum effects.

ISBN: 0-9708275-0-4
Pages: 638