2019 · 20 citations · 9 references
EngineeringElectrical EngineeringMaterials EngineeringElectronic MaterialsMicroelectronicsSemiconductor DevicesComplementary Metal-oxide-semiconductor TechnologyField-effect TransistorsMetal-oxide-semiconductor Field-effect TransistorsThin-film TransistorsEnergy Band Gap
In this paper, a novel TFET architecture named the step-shaped gate TFET (SSG-TFET) has been proposed for the suppression of the ambipolar current. By adjusting the energy band, the SSG-TFET can evidently reduce the ambipolar current. We compare the proposed SSG-TFET with the conventional DGTFET, gate overlap on drain TFET (OGTFET) and gate underlap TFET (SG-TFET) by using TCAD tool Sentaurus and found that the SSG-TFET can evidently suppress the ambipolar current. To be specific, the ambipolar current of the SSG-TFET decreases 7 orders of magnitude from 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-9</sup> A/μm for conventional TFET to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-16</sup> A/μm at V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">gs</sub> = -1.5 V. For the proposed SSG-TFET, we have found that there exists an optimal right gate dielectric thickness t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">oxdb</sub> with minimum ambipolar current of SSG-TFET. Moreover, we investigate the influence of the Si body thickness t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">si</sub> , the length of the oxide layer exceeds the interface of channel and the drain on the optimal thickness of the right gate dielectric of the SSG-TFET. The simulation results show that the optimal oxide layer thickness t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">oxdb</sub> decreases with the increase of t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">si</sub> , and t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">oxdb</sub> increases with the increase length of L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">un</sub> and L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ov</sub> , but when L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ov</sub> > 40 nm, t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">oxdb</sub> remains the same. The proposed SSG-TFET with low ambipolar current can be used for the ultra-low power integrated circuit applications.
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