Apr 18, 2023

Compact Modeling of 2D Field-Effect Biosensors

Francisco Pasadas1, Tarek El Grour2, Enrique G. Marin1, Alberto Medina-Rull1, Alejandro Toral-Lopez1, Juan Cuesta-Lopez1, Francisco G. Ruiz1, Lassaad El Mir2 and Andrés Godoy1
Compact Modeling of Two-Dimensional Field-Effect Biosensors.
Sensors 2023, 23, 1840.
DOI: 10.3390/s23041840

1 Pervasive Electronics Advanced Research Laboratory (PEARL), Departamento de Electrónica y Tecnología de Computadores, Universidad de Granada,18071 Granada, Spain
2 Laboratory of Physics of Materials and Nanomaterials Applied at Environment (LaPhyMNE) LR05ES14, Faculty of Sciences of Gabes, Gabes University, Erriadh City, Zrig, 6072 Gabes, Tunisia

Abstract: A compact model able to predict the electrical read-out of field-effect biosensors based on two-dimensional (2D) semiconductors is introduced. It comprises the analytical description of the electrostatics including the charge density in the 2D semiconductor, the site-binding modeling of the barrier oxide surface charge, and the Stern layer plus an ion-permeable membrane, all coupled with the carrier transport inside the biosensor and solved by making use of the Donnan potential inside the ion-permeable membrane formed by charged macromolecules. This electrostatics and transport description account for the main surface-related physical and chemical processes that impact the biosensor electrical performance, including the transport along the low-dimensional channel in the diffusive regime, electrolyte screening, and the impact of biological charges. The model is implemented in Verilog-A and can be employed on standard circuit design tools. The theoretical predictions obtained with the model are validated against measurements of a MoS2 field-effect biosensor for streptavidin detection, showing excellent agreement in all operation regimes and leading the way for the circuit-level simulation of biosensors based on 2D semiconductors

FIG: Schematic of a two-dimensional field-effect biosensor. A sketch of the position-dependent potential is also shown, highlighting the surface charge density at the 2D channel (σ2D), at the oxide-electrolyte interface (σ0), and at the membrane-diffuse regions of the electrolyte (σmd). The latter comprises a charge-free layer (Stern layer) and an ion-permeable membrane due to the presence of charged macromolecules, with a diffusion layer located between the barrier oxide surface and the bulk electrolyte. The potential difference from the electrolyte bulk to the barrier oxide surface, ψ0, encompasses two contributions originating from a potential drop (ψ0 − ψm) across the Stern layer extending between the outer Helmholtz plane (OHP) and the barrier oxide surface, and a potential drop across the ion-permeable membrane layer formed by charged macromolecules and the diffuse layer (ψm)

Funding: This work is funded by the Spanish Government MCIN/AEI/10.13039/501100011033 through the projects PID2020-116518GB-I00 and TED2021-129769B-I00 (MCIU/AEI/FEDER-UE); and by FEDER/Junta de Andalucía-Consejería de Transformacion Económica, Industria, Conocimiento y Universidades through the projects P20_00633 and A-TIC-646-UGR20. F. Pasadas acknowledges funding from PAIDI 2020 and the European Social Fund Operational Programme 2014–2020 no. 20804. A. Medina-Rull acknowledges the support of the MCIN/AEI/PTA grant, with reference PTA2020- 018250-I. J. Cuesta-Lopez acknowledges the FPU program FPU019/05132, and A. Toral-Lopez the support of Plan Propio of Universidad de Granada.

Data Availability Statement: The Verilog-A model for 2D EIS BioFETs is available from the corresponding author (fpasadas@ugr.es) upon reasonable request.



Apr 6, 2023

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Apr 5, 2023

ChatGPT leaking Samsung chip secrets is iceberg's tip (?)



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Apr 4, 2023

[paper] Three-Gated Reconfigurable FETs

Giulio Galderisi, Christoph Beyer, Thomas Mikolajick, and Jens Trommer 
Insights into the Temperature Dependent Switching Behaviour of Three-Gated Reconfigurable Field Effect Transistors 
physica status solidi (a) DOI: 10.1002/pssa.202300019

NaMLab gGmbH Dresden (D) 
TU Dresden, Chair of Nanoelectronics, Dresden (D) 

Abstract: Three-Gated Reconfigurable Field Effect Transistors are innovative nanoelectronic devices that are rapidly and increasingly attracting substantial interest in several fields of application thanks to their inherent n-type/p-type reconfiguration capabilities. For this reason, it is of significant importance to acquire a deeper knowledge about the temperature ranges in which such devices can be operated and, at the same time, gather a better understanding of the physical mechanisms that are involved in their operation. To achieve this aim, in-depth observations about the functioning of such devices in an ultra-wide temperature range, spanning from 80 K to 475 K, were performed and are presented for their ambipolar and lowVT operation modes. In view of the data exhibited in this work, it is possible to assess the performances of Three-Gated Reconfigurable Field Effect Transistors within a considerable temperature span and finally provide significant insights on the temperature dependent physical mechanisms regulating their functionality.

FIG: a) Typical Three-Gated RFET transfer characteristic, showing both p-/n-type curves for lowVT and highVT operations together with the ambipolar mode. b) Cross-sectional depiction of a Three-Gated RFET. c) False-colored SEM image of fabricated RFET device, based on 60 nm wide nanochannel. d) Schematic band diagrams of the most relevant operation modes of a Three-Gated RFET: off-states for both lowVT and highVT modes are shown, together with the on-state, which is the same for both operations. e) Table summarizing the possible RFET operations: the highlighted ones will be analyzed in this paper. f) Three-Gated RFET fabrication process flow. g) Ambipolar transfer curves for p/n-type branches, obtained on a different set of devices: the shaded area around the solid line (mean) shows the standard deviation calculated on 50 measured devices. h,i) P-type and n-type transfer curves of the lowVT mode for different values of the drain voltage. l,m) P-type and n-type transfer curves of the lowVT mode for different values of the program voltage. In m) it is possible to observe a shift in the VT when the device is programmed at 1 V: this non-ideality is probably due to traps generated in the gate oxide during measurement. 

Acknowledgements: This work was supported in part by the State budget by the delegates of the Saxon State Parliament and in part by the German Research Foundation (DFG) within the projects number 326384402 and SPP2253 under project number 439891087. 

Apr 3, 2023

#NXP favors #semi #manufacturing in #India



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April 03, 2023 at 08:57AM
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