Electron aspirator using electron\u2013electron scattering in nanoscale silicon

Himma Firdaus,Yukinori Ono,Masahiro Hori,Yasuo Takahashi,Tokinobu Watanabe,Daniel Moraru,Akira Fujiwara

doi:10.1038/s41467-018-07278-8

Himma Firdaus, Yukinori Ono + Show 5 more

Open Access

https://doi.org/10.1038/s41467-018-07278-8

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Abstract

Current enhancement without increasing the input power is a critical issue to be pursued for electronic circuits. However, drivability of metal-oxide-semiconductor (MOS) transistors is limited by the source-injection current, and electrons that have passed through the source unavoidably waste their momentum to the phonon bath. Here, we propose the Si electron-aspirator, a nanometer-scaled MOS device with a T-shaped branch, to go beyond this limit. The device utilizes the hydrodynamic nature of electrons due to the electron–electron scattering, by which the injected hot electrons transfer their momentum to cold electrons before they relax with the phonon bath. This momentum transfer induces an electron flow from the grounded side terminal without additional power sources. The operation is demonstrated by observing the output-current enhancement by a factor of about 3 at 8 K, which reveals that the electron–electron scattering can govern the electron transport in nanometer-scaled MOS devices, and increase their effective drivability.

Highlights

Current enhancement without increasing the input power is a critical issue to be pursued for electronic circuits
We show that the device works as an “electron aspirator”, in which energetic electrons from the inlet induce a net electron flow from the grounded base terminal, resulting in the current enhancement at the outlet
We show that the interface roughness scattering, or what we call “the collision with the wall” in hydrodynamics, plays a significant role as a competing MN scattering against the e-e scattering

Summary

Introduction

Current enhancement without increasing the input power is a critical issue to be pursued for electronic circuits. The device utilizes the hydrodynamic nature of electrons due to the electron–electron scattering, by which the injected hot electrons transfer their momentum to cold electrons before they relax with the phonon bath This momentum transfer induces an electron flow from the grounded side terminal without additional power sources. The operation is demonstrated by observing the output-current enhancement by a factor of about 3 at 8 K, which reveals that the electron–electron scattering can govern the electron transport in nanometer-scaled MOS devices, and increase their effective drivability. Since the e-e scattering itself is a momentum-conserving and energyconserving process, the devices based on this process will guide us to a new concept for high-speed and low-power circuits, and research on this issue with Si, in particular on nanometer scale, is important. We show that the device works as an “electron aspirator”, in which energetic electrons from the inlet (emitter) induce a net electron flow from the grounded base terminal, resulting in the current enhancement at the outlet (collector)

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