Steep subthreshold slope nanowire nanoelectromechanical field-effect transistors (NW-NEMFETs)

We study the effect of polymer coating, pressure, temperature and light on the electrical characteristics of monolayer WSe2 back-gated transistors with quasi-ohmic Ni/Au contacts. We prove that the removal of a layer of poly(methyl methacrylate) or a decrease of the pressure change the device conductivity from p to n-type. We demonstrate a gate-tunable Schottky barrier at the contacts and measure a barrier height of ~70 meV in flat-band condition. We report and discuss a temperature-driven change in the mobility and the subthreshold slope which we use to estimate the trap density at the WSe2/SiO2 interface. We study the spectral photoresponse of the device, that can be used as a photodetector with a responsivity of ~0.5 AW-1 at 700 nm wavelength and 0.37 mW/cm2 optical power.

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Nanowire Tunnel Field Effect Transistors at High Temperature

Journal of Integrated Circuits and Systems ◽

10.29292/jics.v8i2.381 ◽

2013 ◽

Vol 8 (2) ◽

pp. 110-115

Author(s):

Márcio D. V. Martino ◽

Felipe S. Neves ◽

Paula Ghedini Der Agopian ◽

João Antonio Martino ◽

Rita Rooyackers ◽

...

Keyword(s):

Field Effect ◽

Room Temperature ◽

Field Effect Transistors ◽

Drain Current ◽

Transport Mechanisms ◽

Temperature Influence ◽

Subthreshold Slope ◽

Band To Band Tunneling ◽

Trap Assisted Tunneling ◽

Working Principle

The aim of this work is to study how the performance of nanowire tunnel field effect transistors (TFETs) is influenced by temperature variation. First of all, simulated energy band diagrams were presented to justify its fundamental working principle and this analysis was compared to experimental data obtained for temperature ranging from 300 to 420 K. This methodology was performed for different nanowire diameters and bias conditions, leading to a deep investigation of parameters such as the ratio of on-state and off-state current (ION/IOFF) and the subthreshold slope (S). Three different transport mechanisms (band-to-band tunneling, Shockley-Read-Hall generation/recombination and trap-assisted tunneling) were highlighted to explain the temperature influence on the drain current. As the final step, subthreshold slope values for each configuration were compared to the room temperature. Therefore, it was observed that larger nanowire diameters and lower temperatures tended to increase ION/IOFF ratio. Meanwhile, it was clear that band-to-band tunneling prevailed for higher gate voltage bias, resulting in a much slighter temperature effect on the drain current.

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Optimization of Line-Tunneling Type L-Shaped Tunnel Field-Effect-Transistor for Steep Subthreshold Slope

Electronics ◽

10.3390/electronics7110275 ◽

2018 ◽

Vol 7 (11) ◽

pp. 275 ◽

Cited By ~ 2

Author(s):

Faraz Najam ◽

Yun Yu

Keyword(s):

Field Effect ◽

Field Effect Transistor ◽

Field Effect Transistors ◽

Oxide Semiconductor ◽

Subthreshold Slope ◽

Corner Effect ◽

New Device ◽

Optimum Configuration ◽

Effect Transistor ◽

Dual Material

The L-shaped tunneling field-effect-transistor (LTFET) has been recently introduced to overcome the thermal subthreshold limit of conventional metal-oxide-semiconductor field-effect-transistors (MOSFET). In this work, the shortcomings of the LTFET was investigated. It was found that the corner effect present in the LTFET effectively degrades its subthreshold slope. To avoid the corner effect, a new type of device with dual material gates is presented. The new device, termed the dual-gate (DG) LTEFT (DG-LTFET), avoids the corner effect and results in a significantly improved subthreshold slope of less than 10 mV/dec, and an improved ON/OFF current ratio over the LTFET. The DG-LTFET was evaluated for different device parameters and bench-marked against the LTFET. This work presents the optimum configuration of the DG-LTFET in terms of device dimensions and doping levels to determine the best subthreshold, ON current, and ambipolar performance.

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Resistive-gate field-effect transistor exhibiting steep subthreshold slope of 5mV/dec and high ION/IOFF ratio

2016 13th IEEE International Conference on Solid-State and Integrated Circuit Technology (ICSICT) ◽

10.1109/icsict.2016.7998833 ◽

2016 ◽

Author(s):

Qianqian Huang ◽

Zongwei Wang ◽

Yue Pan ◽

Yangyuan Wang ◽

Ru Huang

Keyword(s):

Field Effect ◽

Field Effect Transistor ◽

Subthreshold Slope ◽

Effect Transistor ◽

Steep Subthreshold Slope

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Graphene as a Schottky Barrier Contact to AlGaN/GaN Heterostructures

Materials ◽

10.3390/ma13184140 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4140

Author(s):

Maksym Dub ◽

Pavlo Sai ◽

Aleksandra Przewłoka ◽

Aleksandra Krajewska ◽

Maciej Sakowicz ◽

...

Keyword(s):

Schottky Barrier ◽

Field Effect ◽

Field Effect Transistors ◽

Low Frequency ◽

Frequency Noise ◽

Subthreshold Slope ◽

Subthreshold Current ◽

Barrier Heights ◽

Order Of Magnitude

Electrical and noise properties of graphene contacts to AlGaN/GaN heterostructures were studied experimentally. It was found that graphene on AlGaN forms a high-quality Schottky barrier with the barrier height dependent on the bias. The apparent barrier heights for this kind of Schottky diode were found to be relatively high, varying within the range of φb = (1.0–1.26) eV. AlGaN/GaN fin-shaped field-effect transistors (finFETs) with a graphene gate were fabricated and studied. These devices demonstrated ~8 order of magnitude on/off ratio, subthreshold slope of ~1.3, and low subthreshold current in the sub-picoamperes range. The effective trap density responsible for the 1/f low-frequency noise was found within the range of (1–5) · 1019 eV−1 cm−3. These values are of the same order of magnitude as reported earlier and in AlGaN/GaN transistors with Ni/Au Schottky gate studied as a reference in the current study. A good quality of graphene/AlGaN Schottky barrier diodes and AlGaN/GaN transistors opens the way for transparent GaN-based electronics and GaN-based devices exploring vertical electron transport in graphene.

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