P-Type Tunnel FETs With Triple Heterojunctions

Huang, Jun; Long, Pengyu; Povolotskyi, Michael; Klimeck, Gerhard; Rodwell, M.J.W.

doi:10.1109/jeds.2016.2614915

Cited by 17 publications

(8 citation statements)

References 33 publications

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“…The strong scattering and thermalization in the highly doped source and drain regions have a significant impact on the transport properties of tunneling devices [14], [37]- [42]. Different mechanisms such as electron-electron scattering [43]- [50], electron-phonon scattering, electron-ion scattering, plasmon scattering, etc.…”

Section: Efficient Scattering Modelmentioning

confidence: 99%

Impact of body thickness and scattering on III-V triple heterojunction Fin-TFET modeled with atomistic mode space approximation

Chen,

Ilatikhameneh,

Huang

et al. 2020

Preprint

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The triple heterojunction TFET has been originally proposed to resolve TFET's low ON-current challenge. The carrier transport in such devices is complicated due to the presence of quantum wells and strong scattering. Hence, the full band atomistic NEGF approach, including scattering, is required to model the carrier transport accurately. However, such simulations for devices with realistic dimensions are computationally unfeasible. To mitigate this issue, we have employed the empirical tight-binding mode space approximation to simulate triple heterojunction TFETs with the body thickness up to 12 nm. The triple heterojunction TFET design is optimized using the model to achieve a sub-60mV/dec transfer characteristic under realistic scattering conditions.

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Section: Efficient Scattering Modelmentioning

confidence: 99%

Impact of body thickness and scattering on III-V triple heterojunction Fin-TFET modeled with atomistic mode space approximation

Chen,

Ilatikhameneh,

Huang

et al. 2020

Preprint

Self Cite

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“…Material parameters are extracted from previous Non-Equilibrium Green's function calculations. The homojunction TFET has InGaAs as channel with a band gap of 0.74 eV 10 , and the heterojunction TFET has GaSb as source with a 1.2 eV band gap 11 and InAs as channel with a band gap of 0.76 eV 12 . Band diagram of the ON and OFF states in (a) homojunction and (b) heterojunction TFETs.…”

Section: A Tfet Surface Potentialmentioning

confidence: 99%

Modeling tunnel field effect transistors—From interface chemistry to non-idealities to circuit level performance

Ahmed

Tan

Truesdell

et al. 2018

Journal of Applied Physics

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We present a quasi-analytical model for Tunnel Field Effect Transistors (TFETs) that includes the microscopic physics and chemistry of interfaces and non-idealities. The ballistic band-to-band tunneling current is calculated by modifying the well known Simmons equation for oxide tunneling, where we integrate the Wentzel-Kramers-Brillouin (WKB) tunneling current over the transverse modes. We extend the Simmons equation to finite temperature and non-rectangular barriers using a two-band model for the channel material and an analytical channel potential profile obtained from Poisson's equation. The two-band model is parametrized first principles by calibrating with hybrid Density Functional Theory calculations, and extended to random alloys with a band unfolding technique. Our quasi-analytical model shows quantitative agreement with ballistic quantum transport calculations. On top of the ballistic tunnel current we incorporate higher order processes arising at junctions coupling the bands, specifically interface trap assisted tunneling and Auger generation processes. Our results suggest that both processes significantly impact the off-state characteristics of the TFETs -Auger in particular being present even for perfect interfaces. We show that our microscopic model can be used to quantify the TFET performance on the atomistic interface quality. Finally, we use our simulations to quantify circuit level metrics such as energy consumption. arXiv:1806.06331v3 [cond-mat.mtrl-sci]

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“…As shown in Refs. [11], [13], the band offsets greatly enhance the electric field at the GaSb/InAs tunnel junction and create two resonant states in the GaSb and InAs quantum wells, improving the tunnel probability at ON state. The larger band gap and transport effective mass of the (InAs) x (AlSb) 1−x channel, compared with the original InAs channel, also reduce the ambipolar and the source-to-drain tunneling leakage in the sub-threshold region.…”

Section: The Triple-heterojunction Designmentioning

confidence: 99%

A Multiscale Modeling of Triple-Heterojunction Tunneling FETs

Huang

Long

Povolotskyi

et al. 2017

IEEE Trans. Electron Devices

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A high performance triple-heterojunction (3HJ) design has been previously proposed for tunneling FETs (TFETs). Compared with single heterojunction (HJ) TFETs, the 3HJ TFETs have both shorter tunneling distance and two transmission resonances that significantly improve the ON-state current ($I_{\rm{ON}}$). Coherent quantum transport simulation predicts, that $I_{\rm{ON}}=460\rm{\mu A/\mu m}$ can be achieved at gate length $Lg=15\rm{nm}$, supply voltage $V_{\rm{DD}}=0.3\rm{V}$, and OFF-state current $I_{\rm{OFF}}=1\rm{nA/\mu m}$. However, strong electron-phonon and electron-electron scattering in the heavily doped leads implies, that the 3HJ devices operate far from the ideal coherent limit. In this study, such scattering effects are assessed by a newly developed multiscale transport model, which combines the ballistic non-equilibrium Green's function method for the channel and the drift-diffusion scattering method for the leads. Simulation results show that the thermalizing scattering in the leads both degrades the 3HJ TFET's subthreshold swing through scattering induced leakage and reduces the turn-on current through the access resistance. Assuming bulk scattering rates and carrier mobilities, the $I_{\rm{ON}}$ is dropped from $460\rm{\mu A/\mu m}$ down to $254\rm{\mu A/\mu m}$, which is still much larger than the single HJ TFET case

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P-Type Tunnel FETs With Triple Heterojunctions

Cited by 17 publications

References 33 publications

Impact of body thickness and scattering on III-V triple heterojunction Fin-TFET modeled with atomistic mode space approximation

Impact of body thickness and scattering on III-V triple heterojunction Fin-TFET modeled with atomistic mode space approximation

Modeling tunnel field effect transistors—From interface chemistry to non-idealities to circuit level performance

A Multiscale Modeling of Triple-Heterojunction Tunneling FETs

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