[paper] TMD FETs

Ahmed Mounir^a, Benjamin Iñiguez^a, François Lime^a, Alexander Kloes^b

Theresia Knobloch^c, Tibor Grasser^c

Compact I-V model for back-gated and double-gated TMD FETs

Solid-State Electronics (2023): 108702

DOI: 10.1016/j.sse.2023.108702

a Rovira I Virgili University, Tarragona, Spain
b University of Applied Sciences, Giessen, Germany
c TU Wien, Vienna, Austria

Abstract: A physics-based analytical DC compact model for double and single gate TMD FETs is presented. The model is developed by calculating the charge density inside the 2D layer which is expressed in terms of the Lambert W function that recently has become the standard in SPICE simulators. The current is then calculated in terms of the charge densities at the drain and source ends of the channel. We validate our model against measurement data for different device structures. A superlinear current increase above certain gate voltage has been observed in some MoS2 FET devices, where we present a new mobility model to account for the observed phenomena. Despite the simplicity of the model, it shows very good agreement with the experimental data.

Fig : 2D schematic structure for 2D TMD FETs: (a) a double gated monolayer MoS2 FET. 

(b) a double gated monolayer WSe2 FET. (c)  single back-gated multilayer MoS2 FET. 

(d) single back-gated monolayer FET.

[paper] Extended gate FET pH Sensor

Shaiful Bakhtiar Hashim, Zurita Zulkifli, Sukreen Hana Herman

Design and Simulation of Electrochemical Equivalent Circuit for Extended gate FET pH Sensor Based on Experimental Value Using LTSPICE XVII

researchsquare.com: November 11th, 2021

DOI:10.21203/rs.3.rs-1031896/v1

  
College of Engineering, UiTM, Selangor (MY)

Abstract: A SPICE model for extended-gate field-effect transistor (EGFET) based pH sensor was developed using standard discrete components. Capacitors and resistors were used to represent the sensing and reference electrodes in the EGFET sensor system and the values of the discrete component were varied to see the output of the transistor. These variations were done to emulate the EGFET sensor output in different pH values. It was found that the experimental transfer and output characteristics of the EGFET were very similar to those from the SPICE simulation. Other than that, the changes of value components in the equivalent circuit did not affect the transfer and output characteristics graph, but the capacitor value produced significant output variation in the simulation. This can be related to the modification on the equivalent circuit was done with additional voltage, VSB (source to bulk) to produce the different VT values at different pH.

Fig: EGFET measurement setup

Acknowledgement: The work is partially supported by KEPU Grant ( 600- RMC/KEPU 5/3 (007/2021)) from Universiti Teknologi MARA

[chapter] Near-Threshold Digital Circuits for Nearly-Minimum Energy Processing

Near-Threshold Digital Circuits for Nearly-Minimum Energy Processing

Massimo Alioto

Department of Electrical & Computer Engineering, National University of Singapore

in Enabling the Internet of Things; pp 95-148 

DOI: 10.1007/978-3-319-51482-6_4

This chapter addresses the challenges and the opportunities to perform computation with nearly-minimum energy consumption through the adoption of logic circuits operating at near-threshold voltages. Simple models are provided to gain an insight into the fundamental design tradeoffs. A wide set of design techniques is presented to preserve the nearly-minimum energy feature in spite of the fundamental challenges in terms of performance, leakage and variations. Emphasis is given on debunking the incorrect assumptions that stem from traditional low-power common wisdom at above-threshold voltages. The traditional EKV model is very useful for quick estimates, but it oversimplifies the IV characteristics that is observed in actual nanometer CMOS technologies [read more...]