Aug 5, 2020

[paper] GCC Method for Determining MOSFET VTH

Matthias Bucher1, Nikolaos Makris1, Loukas Chevas1
Generalized Constant Current Method for Determining MOSFET Threshold Voltage
arXiv:2008.00576v1 (2 Aug 202) 
has been submitted to the IEEE for possible publication

1 School of Electrical and Computer Engineering, Technical University of Crete

Abstract: A novel method for extracting threshold voltage (VTH) and substrate effect parameters of MOSFETs with constant current bias at all levels of inversion is presented. This generalized constant-current (GCC) method exploits the charge-based model of MOSFETs to extract threshold voltage and other substrate-effect related parameters. The method is applicable over a wide range of current throughout weak and moderate inversion and to some extent in strong inversion. This method is particularly useful when applied for MOSFETs presenting edge conduction effect (subthreshold hump) in CMOS processes using Shallow Trench Isolation (STI).
Fig:  Application of the GCC method in presence of edge conduction phenomenon in STI MOSFETs. A constant current is applied to determine pinchoff voltage for the center transistor in moderate inversion at IC=2. To characterize the edge transistor, imposing a current criterion IC=1E−4 corresponds to ICe≈0.02. Pinchoff voltage (VP) and slope factor n characteristics illustrate the determination of parameters for center and edge transistors.

Acknowledgment: This work was partly supported under Project INNOVATION-EL-Crete
(MIS 5002772).





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August 05, 2020 at 10:06AM
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[paper] Macromodels for MEMS Switches

Aurel-Sorin Lup1, Gabriela Ciuprina1, Daniel Ioan1 and Anton Duca1
and Alexandra Nicoloiu2 and Dan Vasilache2
Physics-aware macromodels for MEMS switches
COMPEL International Journal (2020)

1DEE Politehnica, Uni. Bucharest, (R)
2IMT-Bucharest, Bucharest (R)

Abstract: The purpose of this paper is to propose a physics-aware algorithm to obtain radio frequency (RF)- reduced models of micro-electromechanical systems (MEMS) switches and show how, together with multiphysics macromodels, they can be realized as circuits that include both lumped and distributed parameters. The macromodels are extracted with a robust procedure from the solution of Maxwell’s equations with electromagnetic circuit element (ECE) boundary conditions. The reduced model is extracted from the simulations of three electromagnetic field problems, in full-wave regime, that correspond to three configurations: signal lines alone, switch in the up and down positions. The technique is exemplified for shunt switches, but it can be extended for lateral switches. Moreover, the algorithm is able take frequency dependence into account both for the signal lines and for the switch model. For the later, the order of the model is increased until a specified accuracy is achieved. The use of ECE as boundary conditions for the RF simulation of MEMS switches has the advantage that the definition of ports is unambiguous and robust as the ports are clearly defined. The extraction approach has the advantage that the simplified model keeps the basic phenomena, i.e. the propagation of the signal along the lines. As the macromodel is realized with a netlist that uses transmission lines models, the lines’ extension is natural. The frequency dependence can be included in the model, if needed.

Fig: Modeling chain: from continuous models to reduced macromodels

Acknowledgement: The work has been funded by the Operational Programme Human Capital of the Ministry of European Funds through The Financial Agreement 51675/09.07.2019, SMIS code 125125.


Aug 4, 2020

William English, Computer Mouse Co-Creator, Has Passed died July 26 in San Rafael, California. He was 91 years old. https://t.co/q7PNnR694g #semi https://t.co/KOCm8at33a



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August 04, 2020 at 03:37PM
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[paper] SiC MOSFET SPICE Model

Lefdal Hove, Haavard, Ole Christian Spro, Giuseppe Guidi
and Dimosthenis Peftitsis
Improved SiC MOSFET SPICE Model to Avoid Convergence Errors
Materials Science Forum 1004 (July 2020): 856–64
DOI: 10.4028/www.scientific.net/msf.1004.856

Abstract: This paper presents improvements to a SPICE model for a commercially available SiC MOSFET to avoid convergence errors while still providing reliable simulation results. Functionality in the internal part of the model that shapes the transconductance of the device according to its junction temperature and gate-source voltage dependency has been improved to provide a continuous characteristic rather than the initial discontinuous performance. Furthermore, the output characteristics from the initial and the proposed model have been compared to lab measurements of an actual device. The results show that the proposed and initial model provide equally reliable simulation results. However, the proposed model does not run into convergence problems.

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