High-speed electronic devices rely on short carrier transport times, which are usually achieved by decreasing the channel length and/or increasing the carrier velocity. Ideally, the carriers enter into a ballistic transport regime in which they are not scattered1. However, it is difficult to achieve ballistic transport in a solid-state medium because the high electric fields used to increase the carrier velocity also increase scattering2. Vacuum is an ideal medium for ballistic transport, but vacuum electronic devices commonly suffer from low emission currents and high operating voltages. Here, we report the fabrication of a low-voltage field-effect transistor with a vertical vacuum channel (channel length of ∼20 nm) etched into a metal–oxide–semiconductor substrate. We measure a transconductance of 20 nS µm–1, an on/off ratio of 500 and a turn-on gate voltage of 0.5 V under ambient conditions. Coulombic repulsion in the two-dimensional electron system3 at the interface between the oxide and the metal or the semiconductor reduces the energy barrier to electron emission, leading to a high emission current density (∼1 × 105 A cm–2) under a bias of only 1 V. The emission of two-dimensional electron systems into vacuum channels could enable a new class of low-power, high-speed transistors.
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Sze, S. M. (ed.) High-Speed Semiconductor Devices (Wiley, 1990).
Leitenstorfer, A. et al. Femtosecond high-field transport in compound semiconductors. Phys. Rev. B 61, 16642–16652 (2000).
Ando, T., Fowler, A. B. & Stern, F. Electronic properties of two-dimensional systems. Rev. Mod. Phys. 54, 437–672 (1982).
Torium, A. et al. Experimental determination of finite inversion layer thickness in thin gate oxide MOSFETs. Surf. Sci. 170, 363–369 (1986).
Mead, C. A. Anomalous capacitance of thin dielectric structures. Phys. Rev. Lett. 6, 545–546 (1961).
Black, C. T. & Welser, J. J. Electric-field penetration into metals: consequences for high-dielectric-constant capacitors. IEEE Trans. Electron. Dev. 46, 776–780 (1999).
Han, S. & Ihm, J. Role of the localized states in field emission of carbon nanotubes. Phys. Rev. B 61, 9986–9989 (2000).
Zheng, X. et al. Quantum-mechanical investigation of field-emission mechanism of a micrometer-long single-walled carbon nanotube. Phys. Rev. Lett. 92, 106803 (2004).
Mayer, A. Polarization of metallic carbon nanotubes from a model that includes both net charges and dipoles. Phys. Rev. B 71, 235333 (2005).
Child, C. D. Discharge from hot CaO. Phys. Rev. 32, 492–511 (1911).
Langmuir, I. The effect of space charge and residual gases on thermionic currents in high vacuum. Phys. Rev. 2, 450–486 (1913).
Grinberg, A. A., Luryi, S., Pinto, M. R. & Schryer, N. L. Space-charge-limited current in a film. IEEE Trans. Electron. Dev. 36, 1162–1170 (1989).
Fowler, R. H. & Nordheim, L. Electron emission in intense electric fields. Proc. R. Soc. Lond. 119, 173–181 (1928).
Spindt, C. A. A thin-film field-emission cathode. J. Appl. Phys. 39, 3504–3505 (1968).
De Heer, W. A., Châtelain, A. & Ugarte, D. A carbon nanotube field-emission source. Science 270, 1179–1180 (1995).
Teo, K. B. K. et al. Carbon nanotubes as cold cathodes. Nature 437, 968 (2005).
Brodie, I. & Muray, J. J. The Physics of Micro/Nano-Fabrication (Plenum, 1992).
Mil'shtein, S., Paludi, C. A. Jr, Chau, P. & Awrach, J. Perspectives and limitations of vacuum microtubes. J. Vac. Sci. Technol. A 11, 3126–3129 (1993).
Lau, Y. Y., Liu, Y. & Parker, R. K. Electron emission: from the Fowler–Nordheim relation to the Child–Langmuir law. Phys. Plasmas 1, 2082–2085 (1994).
Yang, G., Chen, K. K. & Marcus, R. B. Electron field emission through a very thin oxide layer. IEEE Trans. Electron. Dev. 38, 2373–2376 (1991).
Yun, M., Turner, A., Roedel, R. J. & Kozicki, M. N. Novel lateral field emission device fabricated on silicon-on-insulator material. J. Vac. Sci. Technol. B 17, 1561–1566 (1999).
Luryi, S. Quantum capacitance devices. Appl. Phys. Lett. 52, 501–503 (1988).
Eisenstein, J. P., Pfeiffer, L. N. & West, K. W. Negative compressibility of interacting two-dimensional electron and quasiparticle gases. Phys. Rev. Lett. 68, 674–677 (1992).
Huang, J. et al. Interaction effects in the transport of two-dimensional holes in GaAs. Preprint at http://arxiv.org/abs/cond-mat/0610320 (2006).
Ho, L. H. et al. Ground-plane screening of Coulomb interactions in two-dimensional systems: how effectively can one two-dimensional system screen interactions in another. Phys. Rev. B 80, 155412 (2009).
Li, L. et al. Very large capacitance enhancement in a two-dimensional electron system. Science 332, 825–828 (2011).
Toriumi, A., Iwase, M. & Yoshimi, M. On the performance limit for Si MOSFETs: experimental study. IEEE Trans. Electron. Dev. 35, 999–1003 (1988).
Pinto, M. R., Sangiorgi, E. & Bude, J. Silicon MOS transconductance scaling into the overshoot regime. IEEE Electron. Dev. Lett. 14, 375–378 (1993).
Novoselov, K. S. et al. Electric field effect in atomically thin carbon films. Science 306, 666–669 (2004).
Wu, Y. Q. et al. Record high RF performance for epitaxial graphene transistors. IEDM Tech. Dig. 528–530 (2011).
This work was supported by the National Science Foundation (grant no. ECCS-0925532).
The authors declare no competing financial interests.
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Srisonphan, S., Jung, Y. & Kim, H. Metal–oxide–semiconductor field-effect transistor with a vacuum channel. Nature Nanotech 7, 504–508 (2012). https://doi.org/10.1038/nnano.2012.107
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