Scalable GaSb/InAs tunnel FETs with non-uniform body thickness

Abstract

GaSb/InAs heterojunction tunnel field-effect transistors are strong candidates in building future low-power integrated circuits, as they could provide both steep subthreshold swing and large ON-state current ($I_{\mathrm{ON}}$). However, at short channel lengths they suffer from large tunneling leakage originating from the small band gap and small effective masses of the InAs channel. As proposed in this article, this problem can be significantly mitigated by reducing the channel thickness meanwhile retaining a thick source-channel tunnel junction, thus forming a design with a non-uniform body thickness. Because of the quantum confinement, the thin InAs channel offers a large band gap and large effective masses, reducing the ambipolar and source-to-drain tunneling leakage at OFF state. The thick GaSb/InAs tunnel junction, instead, offers a low tunnel barrier and small effective masses, allowing a large tunnel probability at ON state. In addition, the confinement induced band discontinuity enhances the tunnel electric field and creates a resonant state, further improving $I_{\mathrm{ON}}$. Atomistic quantum transport simulations show that ballistic $I_{\mathrm{ON}}=284$A/m is obtained at 15nm channel length, $I_{\mathrm{OFF}}=1\times 10^{-3}$A/m, and $V_{\mathrm{DD}}=0.3$V. While with uniform body thickness, the largest achievable $I_{\mathrm{ON}}$ is only 25A/m. Simulations also indicate that this design is scalable to sub-10nm channel length.

arXiv comment4 pages, 8 figures

References in corpus (3)

• On the possibility of obtaining MOSFET-like performance and sub-60 mV/decade swing in 1D broken-gap tunnel transistors
• Heterojunction Vertical Band-to-Band Tunneling Transistors for Steep Subthreshold Swing and High ON Current
• Tight binding analysis of Si and GaAs ultra thin bodies with subatomic resolution

Cited by in corpus (1)

• A Multiscale Modeling of Triple-Heterojunction Tunneling FETs