The tool provides a fast simulation of the DC current in a nanoscale double-gate MOSFET. Thermionic emission and source-to-drain tunneling current are included. Therefore, the tool offers an experimental approach to combine the numerical efficiency achieved by compact modeling with the calculation of quantum transport, which is calculated by the non-equilibrium Greens function (NEGF) formalism.

The tool uses a compact and therefore fast analytical calculation of the two-dimensional channel potential. Based on this result, the source-to-drain current is calculated using a one-dimensional NEGF formalism without any further time-consuming iterations between Poisson and NEGF solver.

Although the fundamental current transport is ballistic, an option allows to include a semi-empirical approach to account for backscattering in the channel region.

Limitations:

• In its current version the tool is limited to n-doped silicon DG-MOSFETs with intrinsic channel.
• Channel thickness is restricted to 2 nm to 5 nm. 
• Channel length is limited from 6 nm to 30 nm, but should be at least 2x of its thickness in order to expect an accurate solution from the 2D analytical solution of Poisson's equation, and therefore correctly predicting short channel effects.
• The electrostatic potential is correctly solved for subthreshold region. For above threshold operation, the solution is modified by pinning the surface potential. Although, in this case the potential profile in the drift region of the channel is not correct, the potential barrier height allows calculation of the ballistic current.
• Quantum confinement is only included by a shift of the flatland voltage and empirical fitting of DOS in dependence to the channel thickness. A model parameter allows further fitting of the current by scaling of the DOS.
• Only carriers in the lowest subband are considered. Effective masses can be adapted separately for confinement and transport direction.

The tool was developed by Device Modeling Research Group of NanoP, THM University of Applied Sciences, Germany.

Matlab code for NEGF implementation is based upon:

Supriyo Datta (2013), "MATLAB codes from "Nanoscale device modeling: the Green's function method"," https://nanohub.org/resources/19564.

Project funding: German Federal Ministry of Education and Research (BMBF), project no. FKZ 03FH001I3

[1] F. Hosenfeld, F. Horst, B. Iniguez, F. Lime, A. Kloes, A quantum wave based compact modeling approach for the current in ultra-short DG MOSFETs suitable for rapid multiscale simulations, Solid-State Electronics, Vol. 137, pp. 70-79, 2017

[2] F. Hosenfeld, F. Horst, M. Graef, A. Farokhnejad, F. Hain, G. V. Luong, Q.T. Zhao, B. Iniguez, A. Kloes, Rapid NEGF-based calculation of ballistic current in ultra-short DG MOFSETs for circuit simulation, International Journal of Microelectronics and Computer Science, Vol. 7, No. 2, pp. 65-72, 2016

[3] F. Hosenfeld, NEGF based analytical modeling of advanced MOSFETs, PhD thesis, Universitat Rovira i Virgili, Spain, 2017

[4] M. Schwarz, T. Holtij, A. Kloes, B. Iniguez,  Analytical Compact Modeling Framework for the 2D Electrostatics in Lightly Doped Double-Gate MOSFETs, Solid-State Electronics, Vol. 69, No. 1, March 2012

Researchers should cite this work as follows:

• Fabian Hosenfeld, Alexander Kloes (2020), "Compact NEGF-Based Solver for Double-Gate MOSFETs," https://nanohub.org/resources/cnegfmos. (DOI: 10.21981/DDVA-0459).

  BibTex | EndNote

1. analytical model
2. ballistic MOSFET
3. Compact Model
4. double gate
5. double gate trasistor
6. MOSFET
7. nanoelectronics
8. nano MOSFET
9. NEGF