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3D-TCAD benchmark of two-gate dual-doped Reconfigurable FETs on  FDSOI28 technology

C. Navarro, L. Donetti, J.L. Padilla, C. Medina-Bailon, J.C. Galdon, C. Marquez, C. Sampedro, F. Gamiz, Solid-State Electronics, Volume 200, February 2023, 108577, https://doi.org/10.1016/j.sse.2022.108577.

Through 3D-TCAD simulations this work aims to demonstrate the benefits of Reconfigurable FETs based on dual doping with respect to the Schottky junctions counterparts using the 28 nm FDSOI platform. These devices feature both N and P dopant species at source and drain to allow for electron and hole symmetrical currents instead of using mid-gap metallic regions. Quasi-static results reveals much larger currents thanks to the enhanced carrier injection with analogous capacitances, leading to faster logic circuits in mixed-mode simulations. Dynamic results also show lower energy-delay products making these devices more efficient and appealing to implement reprogrammable logic.

Towards a DFT-based layered model for TCAD simulations of MoS2

L. Donetti, C. Marquez, C. Navarro, C. Medina-Bailon, J.L. Padilla, C. Sampedro, F. Gamiz, Solid-State Electronics, Volume 197, 2022, 108437, ISSN 0038-1101, https://doi.org/10.1016/j.sse.2022.108437.

In this work, we employ the results of atomistic DFT calculation to extract useful parameters for the simulation of few-layers MoS2 structures with traditional TCAD tools. In particular, we focus on the charge distribution, which allows us to obtain a layered model for the dielectric constant, and on the effective densities of states in the conduction and valence bands taking into account the full 2D density of states. Using this model, we compute the capacitance of a metal–oxide–semiconductor structure and compare it to the one obtained employing a uniform model with averaged effective parameters.

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DFT-based layered dielectric model of few-layer MoS2

L. Donetti, C. Navarro, C. Marquez, C. Medina-Bailon, J.L. Padilla, F. Gamiz, Solid-State Electronics, 2022, https://doi.org/10.1016/j.sse.2022.108346.

We employ atomistic calculations to study charge distribution in few-layer MoS 2  structures with an applied perpendicular electric field. The results suggest a simple continuum model consisting of alternating regions which represent the semiconductor layers and the Van der Waals gaps between them. Such model is a first step towards an accurate simulation of MoS 2  in TCAD tools.

Performance of FDSOI double-gate dual-doped reconfigurable FETs

C. Navarro, L. Donetti, J.L Padilla, C. Medina, J. Ávila, J.C. Galdón, M. Recio, C. Márquez, C. Sampedro, F. Gámiz, Solid-State Electronics, Volume 194, 2022, https://doi.org/10.1016/j.sse.2022.108336.

In this work, the electrical performance of a novel reprogrammable FDSOI device with dual-doping at source/drain and only two top gates is investigated through advanced 3D TCAD simulations. The static and dynamic operations are evaluated and compared with those of traditional Schottky barrier RFETs and standard 28 nm FDSOI MOS transistors under manufacturable geometries.

Improved inter-device variability in graphene liquid gate sensors by laser treatment

Jorge Ávila, Jose C. Galdon, Maria-Isabel Recio, Norberto Salazar, Carlos Navarro, Carlos Marquez, Francisco Gamiz, Solid-State Electronics, Volume 192, 2022, https://doi.org/10.1016/j.sse.2022.108259.

We investigate the influence of a visible laser treatment on the electrical performance of CVD-grown graphene-based liquid gate sensors. This method allows us to treat locally the graphene sheet, improving the performance of the structure for biochemical sensing applications. It was found critical to control the atmosphere in which the laser treatment takes place. An optimized ambient-air laser exposure shifted the Dirac point (minimum of the conductivity voltage) around 300   mV to lower voltages, together with a decrease of the inter-device electrical variability. These results open the door to use the laser treatment to increase the sensibility and reproducibility of liquid gate graphene-based devices as sensors or biosensors.

Hysteresis in As-Synthesized MoS Transistors: Origin and Sensing Perspectives

Marquez, C.; Salazar, N.; Gity, F.; Galdon, J.C.; Navarro, C.; Sampedro, C.; Hurley, P.K.; Chang, E.Y.; Gamiz, F. Micromachines   2021 12 , 646. https://doi.org/10.3390/mi12060646

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Performance and reliability in back-gated CVD-grown MoS2 devices

Carlos Marquez, Norberto Salazar, Farzan Gity, Jose C. Galdon, Carlos Navarro, Ray Duffy, Paul Hurley, Francisco Gamiz, Solid-State Electronics, Volume 186, 2021, 108173, ISSN 0038-1101, https://doi.org/10.1016/j.sse.2021.108173.

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