Showing posts with label spice. Show all posts
Showing posts with label spice. Show all posts

Feb 17, 2021

[papers] Compact/SPICE Modeling

[1] Peled, A, Amrani, O, Rosenwaks, Y.; DC and transient models of the MSET device; Int J Numer Model. 2021;e2869. https://doi.org/10.1002/jnm.2869
Abstract: As a multigate device, the multiple‐state electrostatically formed nanowire transistor (MSET) exhibits a rather complex characteristic on account of the coupling between each of its two adjacent terminals. The MSET has shown promise across a steadily growing range of applications and integrated circuit components. However, an analytical model of the MSET has not been formulated. The objective of this work was to develop practical DC and transient models of the MSET. The modeling approach comprises two stages: the first stage consists of a bottom‐up derivation of the I–V characteristics from the fundamental physical level using the physical processes within the device to derive equations that describe its steady‐state behavior; the second stage proposes a set of analytical equations more applicable to simulation environments. A transient model that considers device parasitic capacitance is also established. The models are validated against robust model simulations in TCAD Sentaurus and Cadence Virtuoso.

[2] Ciou, Jhang-Yan, Sourav De, Wallace Lin, Yao-Jen Lee, and Darsen Lu. "Analytical Modelling of Ferroelectricity Instigated Enhanced Electrostatic Control in Short-Channel FinFETs." arXiv e-prints (2020): arXiv-2007.
Abstract: This study simulated negative-capacitance double gate FinFETs with channel lengths ranging from 25nm to 100nm using TCAD. The results show that negative capacitance significantly reduces subthreshold swing as well as drain induced barrier lowering effects. The improvement is found to be significantly more prominent for short channel devices than long ones, which demonstrates the tremendous advantage of negative capacitance gate stack for scaled MOSFETs. A compact analytical formulation is developed to quantify sub-threshold swing improvement for short channel devices.
Fig: (a) Three-dimensional NC FinFET structure studied insimulation. (b) List of nominal device parameters used in TCAD simulation.

[3] Ahmed, Sheikh Z., Samiran Ganguly, Yuan Yuan, Jiyuan Zheng, Yaohua Tan, Joe C. Campbell, and Avik W. Ghosh. "A Physics Based Multiscale Compact Model of pin Avalanche Photodiodes." arXiv preprint arXiv:2102.04647 (2021).
Abstract: III-V material based digital alloy Avalanche Photodiodes (APDs) have recently been found to exhibit low noise similar to Silicon APDs. The III-V materials can be chosen to operate at any wavelength in the infrared spectrum. In this work, we present a physics-based SPICE compatible compact model for APDs built from parameters extracted from an Environment-Dependent Tight Binding (EDTB) model calibrated to ab-initio Density Functional Theory (DFT) and Monte Carlo (MC) methods. Using this approach, we can accurately capture the physical characteristics of these APDs in integrated photonics circuit simulations.
Fig: Schematic diagram of avalanche photodiode model and testbench used in the SPICE simulations.


Feb 11, 2021

[thesis] SPICE modeling of light and radiation effects in ICs

A novel approach for SPICE modeling of light and radiation effects in ICs
Chiara ROSSI
Présentée le 29 janvier 2021
à la Faculté des sciences et techniques de l’ingénieur Groupe de scientifiques IEL
Programme doctoral en microsystèmes et microélectronique
pour l’obtention du grade de Docteur ès Sciences
DOI:10.5075/epfl-thesis-8422

Modeling the interaction of ionizing radiation, either light or ions, in integrated circuits is essential for the development and optimization of optoelectronic devices and of radiation-tolerant circuits. Whereas for optical sensors photogenerated carriers play an essential role, high energy ionizing particles can be a severe issue for circuits, as they create high density of excess carriers in ICs substrate, causing parasitic signals. In particular, recent advances in CMOS scaling have made circuits more sensitive to errors and dysfunctions caused by radiation-induced currents, even at the ground level. TCAD simulations of excess carriers generated by light or radiation are not dedicated to large scale circuit simulations since only few devices can be simulated at a time and computation times are too long. Conversely, SPICE simulations are faster, but their accuracy is strictly dependent on the correctness of the compact models used to describe the devices, especially when dealing with photocurrents and parasitic radiation-induced currents.
The objective of this thesis is to develop a novel modeling approach for SPICE compatible simulations of electron-hole pairs generated by light and by high energy particles. The approach proposed in this work is based on the Generalized Lumped Devices, previously developed to simulate parasitic signals in High Voltage MOSFET ICs. Here, the model is extended to include excess carriers generation. The developed approach allows physics-based simulations of semiconductor structures, hit by light or radiation, that can be run in standard circuit simulators without the need for any empirical parameter, only relying on the technological and geometrical parameters of the structure, and without any predefined compact model. The model is based on a coarse mesh of the device to obtain an equivalent network of Generalized Lumped Devices. The latter predicts generation of excess carriers and their propagation, recombination and collection at circuit nodes through the definition of equivalent voltages, proportional to the excess carrier concentrations, and equivalent currents, proportional to the excess carrier gradients. The model is validated with commercial TCAD numerical simulations for different scenarios. Regarding light effects, the proposed strategy is applied to simulate various optoelectronic devices. Complete DC I-V characteristics of a solar cell and transient response of a photodiode are studied. Next, phototransistors are considered. After, a full pixel of a 3T-APS CMOS image sensor is analyzed. The photosensing device, described with Generalized Devices, is co-simulated with the in-pixel circuit, described with compact models. The impact of semiconductor parameters on pixel output and on crosstalk between adjacent pixels is predicted. Finally, radiation-induced soft errors in ICs are examined. Alpha particles at different energies hitting the substrate are simulated. Parasitic currents collected at contacts are studied as a function of particles position and energy. Funneling effect, which is a phenomenon specific to high injection, is also included in the model.
This work shows that the Generalized Lumped Devices approach can be successfully used for SPICE simulations of optoelectronic devices and for prediction of radiationinduced parasitic currents in ICs substrate. This thesis is a first step towards a complete and flexible tool for excess carriers modeling in standard circuit simulators.
Fig: Layout, mesh (gray dashed lines) and equivalent network of Generalized Lumped Devices (Generalized Homojunctions, Resistors and Diodes). The structure is uniformly illuminated from the left side, justifying a 1D discretization scheme.


Feb 10, 2021

[papers] Compact/SPICE Modeling

[1] Kotecha, Ramachandra M., Md Maksudul Hossain, Arman Rashid, Asif Emon, Yuzhi Zhang, and Homer Ei C. Alan Mantooth. "Compact Modeling of High-Voltage Gallium Nitride Power Semiconductor Devices for Advanced Power Electronics Design." IEEE Open Journal of Power Electronics (2021)

Fig: (a) Structure of field-plated GaN transistor (b) Equivalent sub-circuit topology


[2] Sengupta, Sarmista, and Soumya Pandit. "A Unified Model of Drain Current Local Variability due to Channel Length Fluctuation for an n-Channel EδDC MOS Transistor." (researchsquare.com 2021).
Fig: Schematic diagram of an Epitaxial δ doped n-channel MOS transistor used for design purpose and the graded retrograde approximation of the channel profile of EδDC transistor.


[3] Patil, C.V., Suma, M.S. Compact modeling of through silicon vias for thermal analysis in 3-D IC structures. Sādhanā 46, 35 (2021). https://doi.org/10.1007/s12046-020-01549-1
Fig: Through Silicon Via 2D representation and its equivalent subcircuit.







Jan 12, 2021

[paper] Modeling Power GaN-HEMTs in SPICE

Utkarsh Jadli, Faisal Mohd-Yasin, Hamid Amini Moghadam, Peyush Pande*, Mayank Chaturvedi and Sima Dimitrijev
Modeling Power GaN-HEMTs Using Standard MOSFET Equations and Parameters in SPICE
Electronics 2021, 10, 130
DOI: 10.3390/electronics10020130

Queensland Micro- and Nanotechnology Centre, Griffith University, Brisbane, QLD 4111, Australia;
*Electronics Department, Graphic Era (Deemed to Be University), Dehradun, Uttarakhand 248002, India;

Abstract: The device library in the standard circuit simulator (SPICE) lacks a gallium nitride based high-electron-mobility-transistor (GaN-HEMT) model, required for the design and verification of power-electronic circuits. This paper shows that GaN-HEMTs can be modeled by selected equations from the standard MOSFET LEVEL3 model in SPICE. A method is proposed for the extraction of SPICE parameters in these equations. The selected equations and the proposed parameter-extraction method are verified with measured static and dynamic characteristics of commercial GaN-HEMTs. Furthermore, a double pulse test is performed in LTSpice and compared to its manufacturer model to demonstrate the effectiveness of the MOSFET LEVEL3 model. The advantage of the proposed approach to use the MOSFET LEVEL3 model, in comparison to the alternative behavioral-based model provided by some manufacturers, is that users can apply the proposed method to adjust the parameters of the MOSFET LEVEL3 model for the case of manufacturers who do not provide SPICE models for their HEMTs.

Fig: Internal cross-sectional structure of GaN-HEMT

Acknowledgments: The authors would like to acknowledge the Innovative Manufacturing Co- operative Research Centre (IMCRC) for providing a PhD scholarship to the first author. We also acknowledge the School of Engineering and Built Environments (EBE) of Griffith University for funding this project. This work was performed in part at the Queensland node of the Australian National Fabrication Facility, a company established under the National Collaborative Research Infrastructure Strategy to provide nano- and micro-fabrication facilities for Australia’s researchers.

Jan 4, 2021

[paper] Compact Modeling of Carbon Nanotube FETs

A Compact and Robust Technique for the Modeling and Parameter Extraction 
of Carbon Nanotube Field Effect Transistors
Laura Falaschetti1, Davide Mencarelli1, Nicola Pelagalli1, Paolo Crippa1, Giorgio Biagetti1,
Claudio Turchetti1,George Deligeorgis2, and Luca Pierantoni1
Electronics 2020, 9(12), 2199; 
DOI: 10.3390/electronics9122199

1 Department of Information Engineering, Marche Polytechnic University, 60131 Ancona, Italy
2 Microelectronics Research Group (MRG/IESL), FORTH, Greece


Abstract: Carbon nanotubes field-effect transistors (CNTFETs) have been recently studied with great interest due to the intriguing properties of the material that, in turn, lead to remarkable properties of the charge transport of the device channel. Downstream of the full-wave simulations, the construction of equivalent device models becomes the basic step for the advanced design of high-performance CNTFET-based nanoelectronics circuits and systems. In this contribution, we introduce a strategy for deriving a compact model for a CNTFET that is based on the full-wave simulation of the 3D geometry by using the finite element method, followed by the derivation of a compact circuit model and extraction of equivalent parameters. We show examples of CNTFET simulations and extract from them the fitting parameters of the model. The aim is to achieve a fully functional description in Verilog-A language and create a model library for the SPICE-like simulator environment, in order to be used by IC designers.
Figure 2. 3D structure of CNTFET. Reprinted, with permission, from [I and II]

Aknowlwgement: This research was supported by the European Project “NANO components for electronic SMART wireless circuits and systems (NANOSMART)”, H2020—ICT-07-2018-RIA, n. 825430.

References:
[I] Deng, J.; Wong, H.P. A Compact SPICE Model for Carbon-Nanotube Field-Effect Transistors Including non-idealities and Its Application—Part I: Model of the Intrinsic Channel Region. IEEE Trans. Electron Devices 2007, 54, 3186–3194
[II] Deng, J.; Wong, H.P. A Compact SPICE Model for Carbon-Nanotube Field-Effect Transistors Including non-idealities and Its Application—Part II: Full Device Model and Circuit Performance Benchmarking. IEEE Trans. Electron Devices 2007, 54, 3195–3205 




Dec 21, 2020

[paper] Cross Domain Modeling of a Meander Beam MEMS Accelerometer

Mahdieh Shojaei Baghini*

*Department of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, Netherlands

Abstract: This paper presents the design of a bulk Silicon MEMS single-axis 8-beam accelerometer utilizing meander beams in the Structural Mechanics and MEMS Module of COMSOL Multiphysics®. To obtain further insights into the design of the accelerometer, an electrical lumped element model of the structure is derived and represented in SPICE. Quantities such as eigenfrequencies and proofmass displacement have been extracted from COMSOL Multiphysics® as well as analytical studies. The effects of parasitic frequencies in the structure are observed by automatic tilting of the accelerometer at higher order eigenfrequencies due to finite off-axis stiffness coefficients. In order to mathematically quantify the response of the accelerometer arising due to parasitic frequencies, the transient damping response has been derived in COMSOL Multiphysics® as well as SPICE, and the differences are highlighted. Finally, the eigenfrequencies of the meanderbeam accelerometer have been compared with that of a simple-beam accelerometer and the validity of small deflection theory is tested for the lumped model approach. While the target damping factor of the accelerometer was 0.7, the obtained damping factor increased to 1.1 due to the aforementioned parasitic frequencies and reduction in the resonance frequency of the sensor. This effect was precisely captured during the COMSOL Multiphysics® simulation.
Fig: The designated sensor is damped using plates placed at a distance equal to h0; its a) electrical circuit equivalent of squeeze-film damped accelerometer; b) electrical circuit considering symmetric damping; c) simplified equivalent circuit for gap height derivation.


Dec 10, 2020

[Foreword] Special Issue on Compact Modeling of Semiconductor Devices

Foreword
Special Issue on Compact Modeling of Semiconductor Devices
DOI: 10.1109/JEDS.2020.3039023

THIS Special Issue is dedicated to recent research in the field of compact modeling of semiconductor devices. This is the first J-EDS Special Issue on compact modeling. In the last years, a number of new semiconductor device structures, for electronic and photonic applications, have been developed. Compact models are needed for the incorporation of these new devices in integrated circuits. Therefore, a Special Issue was needed to present recent compact modeling solutions for semiconductor devices

A total of 8 regular papers and 2 invited papers have been accepted in this Special Issue. All papers, including the invited ones, were subjected to a thorough peer reviewing. A high number of reviewers participated in this process. This has resulted in a Special Issue containing very high-quality papers.  The published papers target compact modeling aspects for a wide number of devices, such as SiGe HBTs, IGBTs, SiC SB diodes, LDMOSFETs, Multi-Gate MOSFETs, RRAMs, TFET SRAMs, and organic TFTs. Open source Verilog-A compil- ing is also targeted by one paper. Different operation regimes and conditions are addressed: charging/discharging, THz, high power, tunneling radiation environments, . . . 

One invited paper, by U. Sharma and S. Mahapatra, addresses the modeling of HCD Kinetics for full VG/VD span under different experimental conditions across architectures and its SPICE implementation The other invited paper, by Fregonese et al., presents a review of THz characterization and modeling of SiGE HBTs.

I [BJ] would like to thank the work done by the rest of the Editors of this Special Issue and also by all the reviewers who participated in this process. And of course, I want to thank all the authors for their interest in submitting papers to this Special Issue. Thanks to authors, reviewers, and editors, this high-quality Special Issue has been possible.

BENJAMIN IÑIGUEZ, Guest Editor-in-Chief
Department of Electronic, Electrical and
Automatic Control Engineering
University Rovira i Virgili
43007 Catalonia, Spain

YOGESH SINGH CHAUHAN, Guest Associate Editor
Department of Electrical Engineering
Indian Institute of Technology Kanpur
Kanpur 208016, India

SLOBODAN MIJALKOVIC, Guest Associate Editor
Simulation Group
EDA Division
Silvaco Europe Ltd.
Cambridgeshire PE27 5JL, U.K.

KEJUN XIA, Guest Associate Editor
Department of Front End Innovation
NXP Semiconductors
Chandler, AZ 85224 USA
JUNG-SUK GOO, Guest Associate Editor
Department of Compact Model Development
GLOBALFOUNDRIES Inc.
Santa Clara, CA 95054 USA

MARCELO PAVANELLO, Guest Associate Editor
Department of Electrical Engineering
Centro Universitario FEI
09850-901 São Bernardo do Campo, Brazil

MAREK MIERZWINSKI, Guest Associate Editor
Department of PathWave Software and Solutions
Keysight Technologies
Santa Rosa, CA 95403 USA
(e-mail: )

WLADEK GRABINSKI, Guest Associate Editor
Department of Research and Development Modelling
GMC Consulting
1291 Commugny, Switzerland

Nov 30, 2020

[paper] SPICE-level Crossbar-array Circuit Simulator

Fan Zhang1 and Miao Hu2 
CCCS: Customized SPICE-level Crossbar-array Circuit Simulator
for In-Memory Computing
IEEE/ACM International Conference on Computer-Aided Design
(ICCAD ’20) November 2– 5, 2020, Virtual Event, USA. 
ACM, New York, NY, USA, 8 pages.
DOI: 10.1145/3400302.3415627
1Arizona State University Tempe, Arizona
2Binghamton University Binghamton, New York


ABSTRACT: Resistive crossbar arrays are known for their unique structure to implement analog in-memory vector-matrix-multiplications (VMM). However, general-purpose circuit simulators, such as HSPICE and HSIM, are too slow for large scale crossbar array simulations with consideration of circuit parasitics. Although there are some specific simulators designed for crossbar arrays, they mainly focus on area/power/delay estimation rather than accurate SPICE-level simulation, thus could not model its functionality on analog in-memory computing. In this paper, we firstly give a SPICE-level modeling of resistive crossbar array with consideration of circuit parasitics in MATLAB. We also propose efficient methods to further speedup simulations by model simplifications. Last but not least, ResNet-20 on CIFAR-10 is applied to demonstrate the work. With the proposed model simplification methods, simulation speed can be improved by ~31X with tolerable errors, and more than 5X speedup is achieved on ResNet-20 while the accuracy drop is 6%.

Figure: Implement the ResNet on the crossbar with sub-block optimization. 

RELATED WORK: Other than general-purpose circuit simulators, specific simulation platforms have been proposed for crossbar-based application analysis; examples include: 
[MNSIM] L. Xia, B. Li, T. Tang, P. Gu, X. Yin, W. Huangfu, P. Chen, S. Yu, Y. Cao, Y. Wang, Y. Xie, and H. Yang. MNSIM: Simulation platform for memristor-based neuromorphic computing system. In 2016 Design, Automation Test in Europe Conference Exhibition (DATE). 469–474.
[NeuroSim] P. Chen, X. Peng, and S. Yu. 2018. NeuroSim: A Circuit-Level Macro Model for Benchmarking Neuro-Inspired Architectures in Online Learning. IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems 37, 12 (Dec 2018), 3067–3080.

Nov 2, 2020

[paper] SPICE Compact Model for Schottky-Barrier FETs

Sheikh Aamir Ahsan, Member, IEEE, Shivendra Kumar Singh, Chandan Yadav, Member, IEEE, Enrique G. Marín, Member, IEEE, Alexander Kloes, Senior Member, IEEE
and Mike Schwarz, Senior Member, IEEE
A Comprehensive Physics-Based Current–Voltage SPICE Compact Model 
for 2-D-Material-Based Top-Contact Bottom-Gated Schottky-Barrier FETs
IEEE Transactions on Electron Devices, vol. 67, no. 11, pp. 5188-5195, Nov. 2020
DOI: 10.1109/TED.2020.3020900

Abstract: In this article, we report the development of a novel physics-based analytical model for explaining the current–voltage relationship in Schottky barrier (SB) 2D material field effect transistors (FETs). The model has at its core the calculation of the surface-potential (SP) which is accomplished by invoking 2-D density of states in conjunction with Fermi–Dirac (FD) distribution for electron and hole statistics. The explicit computation for the SP, carried out using the Lambert-W function together with Halley’s method, is used to construct the SP-based band-diagram for realizing the transparency of the SBs. Thereafter, the ambipolar current is derived in terms of the electron and hole injection phenomena the thermionic emission and Fowler–Nordheim tunneling mechanisms at the SB contacts. Furthermore, drift-diffusion current is derived in terms of the SP and incorporated in the model to account for the scattering in the intrinsic 2D channel. Finally, the Verilog-A model is validated against experimental IV data reported in the literature for two different 2D material systems. This is the first demonstration of an explicit SP-based SPICE model for ambipolar SB-2-D-FETs that is simultaneously built on tunneling-emission and driftdiffusion formalisms.

Fig: (a) Band-diagram sketched along positive y-direction underneath the source electrode. Blue and black lines represent bands before and after applying Vgs. (b) ψ-based diagram sketched along positive x, constructed after calculating ψs and ψd. The geometrical screening length λ is given by λ ≈ (tox t2D)^1/2.

Acknowledgement: This work was supported in part by the National Project Implementation Unit (NPIU) through the third phase of Technical Education Quality Improvement Programme (TEQIP-III) Project and in part by DST-SERB Startup Research Grant under Award SRG/2019/001122.




Oct 27, 2020

[paper] Optomechanical Sensor in Verilog-A

Houssein Elmi Dawale, Loïc Sibeud, Sébastien Regord, Guillaume Jourdan, Member, IEEE, Sébastien Hentz, Member, IEEE, and Franck Badets, Senior Member, IEEE
Compact Modeling and Behavioral Simulation of an Optomechanical Sensor in Verilog-A
IEEE Transactions on Electron Devices, vol. 67, no. 11, pp. 4677-4681, Nov. 2020
DOI: 10.1109/TED.2020.3024477

Abstract: Previous work has shown that optomechanical resonators are particularly well suited to the design of ultrasensitive mass sensors. They present an extremely low noise level, very high optical quality factor (Q>105), excellent integration density and can resonate both in a gaseous and liquid environment. In order to reduce the long measurement time due to their small particle capture area, several such resonators must be integrated onto the same chip. However, bulky laboratory equipment currently used to read a single optomechanical resonator cannot be practically scaled up to a large array of transducers. It is then required to design and eventually integrate a read-out interface that can process tens to thousands of resonators. To ease the design of such a circuit, this article presents a compact analytical model of an electrostatically actuated optomechanical resonator implemented in Verilog-A. The proposed model includes both the optical and mechanical behaviors, as well as optomechanical coupling and thermo-optical effect. It was simulated in commercial simulator and is consistent with the measured results. 
FIG: a) General view of the optomechanical device with electrostatic actuation. 
b) Functional diagram of the device in Verilog-A.











Oct 15, 2020

[paper] Scaled GaN-HEMT Large-Signal Model Based on EM Simulation

Scaled GaN-HEMT Large-Signal Model Based on EM Simulation
Wooseok Lee1, Hyunuk Kang1, Seokgyu Choi2, Sangmin Lee2, Hosang Kwon3, Keum cheol Hwang1, Kang-Yoon Lee1 and Youngoo Yang1
Electronics 2020, 9(4), 632
DOI: 10.3390/electronics9040632
1Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea
2Wavice Inc., Hwaseong-si 18449, Korea
3Agency for Defense Development, Daejeon 34186, Korea

Abstract This paper presents a scaled GaN-HEMT large-signal model based on EM simulation. A large-signal model of the 10-finger GaN-HEMT consists of a large-signal model of the two-finger GaN-HEMT and an equivalent circuit of the interconnection circuit. The equivalent circuit of the interconnection circuit was extracted according to the EM simulation results. The large-signal model for the two-finger device is based on the conventional Angelov channel current model. The large-signal model for the 10-finger device was verified through load-pull measurement. The 10-finger GaN-HEMT produced an output power of about 20 W for both simulation and load-pull measurements. 
Fig: Two-finger GaN-HEMT: a) layout; b) equivalent SPICE subcircuit

Acknowledgement: The research reported in this work has been supported by ADD (Agency of Defense Development) of Korea under an R&D program (UC170025FD).


[webinar] GaN HEMT Devices Characterization Using ASM-HEMT Model

ASM-HEMTモデルを使ったGaN HEMTデバイスの特性評価とモデリング


お知らせ: キーサイト・テクノロジーのウェブセミナー「ASM-HEMTモデルを使ったGaN HEMTデバイスの特性評価とモデリング 」

ライブウェブセミナーの日付: 2020年10月14日
ライブウェブセミナーの時刻: 10:45 JST

Oct 5, 2020

[paper] TFT Compact Model of AMOLEDs Image‐Retention

A Novel Charge Based TFT Compact Model Applicable 
to Image‐Retention Simulation of AMOLEDs
Genshiro Kawachi 
Tianma Japan Ltd., Kanagawa, Japan
SID Symposium Digest of Technical Papers, 51(1), 1390–1393. 
P‐193: Late‐News‐Poster; First published: 25 September 2020
DOI: 10.1002/sdtp.14145

Abstract: A novel TFT compact model based on surface potential and charge calculations has been developed. Two kinds of non‐quasi‐static (NQS) models are included to describe the transient effects of TFTs. Appling the new model, accurate simulation of image retention phenomena in AMOLEDs was realized.
Fig: Transient response of a 2T1C pixel circuit (a) after switching from black to gray level: (b) simulation assuming a distributed τNQS model and measured results are compared.

Sep 21, 2020

[paper] Memristors in SPICE

Modeling networks of probabilistic memristors in SPICE
Vincent J. Dowling1, Valeriy A. Slipko2, Yuriy V. Pershin1
arXiv:2009.05189v1 [cs.ET] 11 Sep 2020
DOI: 10.13164/re.2020.0001

1Department of Physics and Astronomy, University of South Carolina, Columbia, SC 29208 USA
2Institute of Physics, Opole University, Opole 45-052, Poland

Abstract. Efficient simulation of probabilistic memristors and their networks requires novel modeling approaches. One major departure from the conventional memristor modeling is based on a master equation for the occupation probabilities of network states. In the present article, we show how to implement such master equations in SPICE. In the case studies, we simulate the dynamics of ac-driven probabilistic binary and multi-state memristors, and dc-driven networks of probabilistic binary and multi-state memristors. Our SPICE results are in perfect agreement with known analytical solutions. Examples of LTspice codes are included.
Fig: Ac-driven probabilistic binary memristor: (a) simulated circuit, (b) schematics of SPICE model, and (c) example of current-voltage curves found with SPICE simulations. The listing of SPICE model is given in Apendix.

Appendix: SPICE code examples
B1 0 p0 I=-gm(tau01,V01,V(Va))*V(p0)*u(V(Va))+gm(tau10,V10,-V(Va))*V(p1)*u(-V(Va))
B2 0 p1 I=gm(tau01,V01,V(Va))*V(p0)**u(V(Va))-gm(tau10,V10,-V(Va))*V(p1)**u(-V(Va))
C1 p0 0 1 IC=1
C2 p1 0 1 IC=.0
R2 Va 0 1k
R1 Va 0 10k
R3 VI 0 1k
B3 0 VI I=I(R1)*V(p0)+I(R2)*V(p1)
V1 Va 0 SINE(0 1 200 0 0 0 0)
.FUNC gm(x,y,z)1/(x*exp(-z/y))
.param tau01=3E5 V01=.05
.param tau10=3E5 V10=.05
.tran 0 .1 0.05 10E-7
.backanno
.end

Sep 17, 2020

[paper] Compact Model for MoS2 FETs

A physics-based compact model for MoS2 field-effect transistors
considering the band-tail effect and contact resistance
Yuan Liu1, Jiawei Zeng2, Zeqi Zhu1, Xiao Dong2 and WanLing Deng3
Japan Society of Applied Physics; Accepted Manuscript online 11 September 2020
1Guangdong University of Technology, Guangzhou, Guangdong, CHINA
2Jinan University, Guangzhou, Guangdong, CHINA
3Electronic Engineering, Jinan University, Guangzhou, GuangDong, 510630, CHINA

Abstract: In this paper, we present a compact surface-potential-based drain current model in molybdenum disulfide (MoS2) field-effect transistors (FETs). Considering variable range hopping (VRH) transport via band-tail states in MoS2 transistors, an explicit solution for surface potential has been derived and it provides a good description over different regions of operation by comparisons with numerical data. Based on charge-sheet model (CSM) which applies to drift-diffusion transport, the current expression including contact resistance and velocity saturation effect is developed. Furthermore, the presented model is validated and shows a good agreement with experiment data for MoS2 FETs. Keywords: molybdenum disulfide (MoS2), surface potential, current expression.


Aug 4, 2020

[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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[6] C. Enz, F. Krummenacher, and E. Vittoz, An Analytical MOS Transistor Model Valid in All Regions of Operation and Dedicated to Low-Voltage and Low-Current Application, Analog Integrated Circuits and Signal Processing, vol. 8, p.83–114, (1995).
[7] M. Bucher, C. Lallement, C. Enz, F. Théodoloz, and F. Krummenacher, The EPFL-EKV MOSFET Model Equations for Simulation Technical Report V2.6,, EPFL, Lausanne, Switzerland, (1999).
[8] B. N. Pushpakaran, S. B. Bayne, G. Wang, and J. Mookken, Fast and accurate electro-thermal behavioral model of a commercial SiC 1200V, 80 mΩ power MOSFET,, Digest of Technical Papers IEEE IPPC, vol. 2015-Octob, p.1–5, (2015).

Jul 23, 2020

[paper] Symmetric Source and Drain Voltage Clamping Scheme

K. Xia1 (Senior Member, IEEE)
Symmetric Source and Drain Voltage Clamping Scheme
for Complete Source-Drain Symmetry in Field-Effect Transistor Modeling
in IEEE Transactions on Electron Devices
DOI: 10.1109/TED.2020.3004799

1NXP Semiconductors N.V., Chandler, AZ 85224 USA

Abstract: For structurally symmetric field-effect transistors with respect to the source and the drain, their models should be electrically symmetric about the source-drain interchange. This article shows that the commonly used drain-source voltage clamping technique breaks such a symmetry. This article then presents a symmetric source and drain voltage clamping scheme to solve the problem. The effectiveness of the new scheme is demonstrated by both the planar MOSFET model PSP and the FinFET model BSIM-CMG.
Fig: Fourth order derivative of Ix with respect to Vx during Gummel symmetry test for an n-MOSFET on a 130nm technology. Vg = 1.15V. Vb = 0V. W/L = 10.02μm/0.15μm. Vd = −Vs = Vx. T=27C. Vx stepsize is 10mV in the measurement and 0.1mV in the simulation, respectively.

May 5, 2020

[paper] Two Transistors Voltage-Measurement-Based Test Structure for Fast MOSFET Device Mismatch Characterization

J. P. M. Brito and S. Bampi
Two Transistors Voltage-Measurement-Based Test Structure 
for Fast MOSFET Device Mismatch Characterization
IEEE Transactions on Semiconductor Manufacturing
doi: 10.1109/TSM.2020.2988095

Abstract - This work presents a test structure targeted to measure MOSFET mismatches with a fast method. It relies on two single-spot voltage measurements in order to extract VTH and β/β separately. The new methodology gives a theoretical increase in the measurement speed of 30x (23.17x in practice). The coefficient of determination (R2) of the linear regression analysis is used to compare standalone transistor measurements against the new proposed methodology. The correlation in the data demonstrates values not less than 0.94 (R2≥ 0.94). The test structure can reproduce parameter correlations, and it is capable of extracting MOSFET mismatch design parameters, such as Pelgrom’s AVTH, with an error of 2% and Aβ, with a negligible error. The experimental data presented herein are taken from measurements in prototypes fabricated in a 65nm CMOS bulk process. The whole circuit is composed of 16 2D addressable DUT device matrices, each having 256 same-size closely-placed MOSFET devices, totaling 4,096 MOS devices used in single-type (NMOS) transistor array. 

URL: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9068274&isnumber=5159394

Jan 20, 2020

Qucs-S as R&D design software

Qucs-S 

is not a simple circuit simulator, but also a research software. Please cite your R&D articles, if you are using Qucs-S in your research.

Documentation

Publications

Qucs-S is not a simple circuit simulator, but also a research software. Please cite our articles, if you are using Qucs-S in your research.
  1. Brinson, M. E., and Kuznetsov, V. (2016) A new approach to compact semiconductor device modelling with Qucs Verilog-A analogue module synthesis. Int. J. Numer. Model., 29: 1070-1088. (BibTeX)
  2. D. Tomaszewski, G. Głuszko, M. Brinson, V. Kuznetsov and W. Grabinski, "FOSS as an efficient tool for extraction of MOSFET compact model parameters," 2016 MIXDES - 23rd International Conference Mixed Design of Integrated Circuits and Systems, Lodz, 2016, pp. 68-73. (BibTeX)
  3. M. Brinson and V. Kuznetsov, "Qucs-0.0.19S: A new open-source circuit simulator and its application for hardware design," 2016 International Siberian Conference on Control and Communications (SIBCON), Moscow, 2016, pp. 1-5. (BibTeX)
  4. M. Brinson and V. Kuznetsov, "Improvements in Qucs-S equation-defined modelling of semiconductor devices and IC's," 2017 MIXDES - 24th International Conference "Mixed Design of Integrated Circuits and Systems, Bydgoszcz, 2017, pp. 137-142. (BibTeX)
  5. M. Brinson and V. Kuznetsov, "Extended behavioural device modelling and circuit simulation with Qucs-S" International Journal of Electronics, 2017, pp.1 - 14 (BibTeX)

Nov 19, 2019

MOS-AK India #45395 is now published in IEEE Xplore

2019 IEEE Conference on Modeling of Systems Circuits and Devices 
(MOS-AK India) - #45395 
is now published in IEEE Xplore

Conference Record #45395

Dear Arifuddin Sohel, Desai UB, Govindacharyulu P.A, Wladek Grabinski, Venkatesh N

Congratulations! 2019 IEEE Conference on Modeling of Systems Circuits and Devices (MOS-AK India) has been posted to the IEEE Xplore digital library effective 2019-11-18.

Along with publication in IEEE Xplore, IEEE assures wide distribution of conference proceedings by providing abstracting and indexing information of all individual conference papers to worldwide databases. IEEE makes every reasonable attempt to ensure that abstracts and index entries of content accepted into the program are included in databases provided by independent abstracting and indexing services. Each abstracting and indexing partner makes its own editorial decision on what content to include. IEEE cannot guarantee entries are included in any particular database.

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