Silicon-based transistors are approaching their physical limits and thus new high-mobility semiconductors are sought to replace silicon in the microelectronics industry. Both bulk materials (such as silicon-germanium and III–V semiconductors) and low-dimensional nanomaterials (such as one-dimensional carbon nanotubes and two-dimensional transition metal dichalcogenides) have been explored, but, unlike silicon, which uses silicon dioxide (SiO2) as its gate dielectric, these materials suffer from the absence of a high-quality native oxide as a dielectric counterpart. This can lead to compatibility problems in practical devices. Here, we show that an atomically thin gate dielectric of bismuth selenite (Bi2SeO5) can be conformally formed via layer-by-layer oxidization of an underlying high-mobility two-dimensional semiconductor, Bi2O2Se. Using this native oxide dielectric, high-performance Bi2O2Se field-effect transistors can be created, as well as inverter circuits that exhibit a large voltage gain (as high as 150). The high dielectric constant (~21) of Bi2SeO5 allows its equivalent oxide thickness to be reduced to 0.9 nm while maintaining a gate leakage lower than thermal SiO2. The Bi2SeO5 can also be selectively etched away by a wet chemical method that leaves the mobility of the underlying Bi2O2Se semiconductor almost unchanged.
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The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.
Kilby, J. S. Invention of the integrated circuit. IEEE Trans. Electron. Dev. 23, 648–654 (1976).
Kingon, A. I., Maria, J. P. & Streiffer, S. K. Alternative dielectrics to silicon dioxide for memory and logic devices. Nature 406, 1032–1038 (2000).
Muller, D. A. et al. The electronic structure at the atomic scale of ultrathin gate oxides. Nature 399, 758–761 (1999).
Van Zant, P. Microchip Fabrication: A Practical Guide to Semiconductor Processing 4th edn, 100–121 (McGraw Hill, 2000).
Ferain, I., Colinge, C. A. & Colinge, J. P. Multigate transistors as the future of classical metal–oxide–semiconductor field-effect transistors. Nature 479, 310–316 (2011).
Aberg, I., Chleirigh, C. N., Olubuyide, O. O., Duan, X. & Hoyt, J. L. High electron and hole mobility enhancements in thin-body strained Si/strained SiGe/strained Si heterostructures on insulator. In Technical Digest of the IEEE International Electron Devices Meeting 2004 173–176 (IEEE, 2004).
Xiang, J. et al. Ge/Si nanowire heterostructures as high-performance field-effect transistors. Nature 441, 489–493 (2006).
Passlack, M. et al. High mobility III–V MOSFETs for RF and digital applications. In Proceedings of the International Electron Devices Meeting 2007 621–624 (IEEE, 2007).
Ohtomo, A. & Hwang, H. Y. A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface. Nature 427, 423–426 (2004).
Qiu, C. G. et al. Scaling carbon nanotube complementary transistors to 5-nm gate lengths. Science 355, 271–276 (2017).
Shulaker, M. M. et al. Carbon nanotube computer. Nature 501, 526–530 (2013).
Desai, S. B. et al. MoS2 transistors with 1-nanometer gate lengths. Science 354, 99–102 (2016).
Li, L. K. et al. Black phosphorus field-effect transistors. Nat. Nanotechnol. 9, 372–377 (2014).
Bandurin, D. A. et al. High electron mobility, quantum Hall effect and anomalous optical response in atomically thin InSe. Nat. Nanotechnol. 12, 223–227 (2017).
Novoselov, K. S. et al. A roadmap for graphene. Nature 490, 192–200 (2012).
Chhowalla, M., Jena, D. & Zhang, H. Two-dimensional semiconductors for transistors. Nat. Rev. Mater. 1, 16052 (2016).
Franklin, A. D. Nanomaterials in transistors: from high-performance to thin-film applications. Science 349, aab2750 (2015).
Li, M. Y., Su, S. K., Wong, H. S. P. & Li, L. J. How 2D semiconductors could extend Moore’s law. Nature 567, 169–170 (2019).
Liu, Y., Duan, X. D., Huang, Y. & Duan, X. F. Two-dimensional transistors beyond graphene and TMDCs. Chem. Soc. Rev. 47, 6388–6409 (2018).
Zhao, H. et al. Effects of gate-first and gate-last process on interface quality of In0.53Ga0.47As metal–oxide–semiconductor capacitors using atomic-layer-deposited Al2O3 and HfO2 oxides. Appl. Phys. Lett. 95, 253501 (2009).
Gutowski, M. et al. Thermodynamic stability of high-κ dielectric metal oxides ZrO2 and HfO2 in contact with Si and SiO2. Appl. Phys. Lett. 80, 1897–1899 (2002).
Maiti, C. K., Samanta, S. K., Chatterjee, S., Dalapati, G. K. & Bera, L. K. Gate dielectrics on strained Si/SiGe heterolayers. Solid State Electron. 48, 1369–1389 (2004).
Toriumi, A. et al. Opportunities and challenges for Ge CMOS—control of interfacing field on Ge is a key. Microelectron. Eng. 86, 1571–1576 (2009).
Hussey, R. J. et al. Thermal oxidation of III–V materials and heterostructures. J. Electrochem. Soc. 149, G581–G584 (2002).
Zhu, H. et al. Remote plasma oxidation and atomic layer etching of MoS2. ACS Appl. Mater. Interfaces 8, 19119–19126 (2016).
Chamlagain, B. et al. Thermally oxidized 2D TaS2 as a high-κ gate dielectric for MoS2 field-effect transistors. 2D Mater. 4, 031002 (2017).
Lai, S. et al. HfO2/HfSe2 hybrid heterostructure fabricated via controllable chemical conversion of two-dimensional HfS2. Nanoscale 10, 18758–18766 (2018).
Yamamoto, M. et al. Self-limiting layer-by-layer oxidation of atomically thin WSe2. Nano Lett. 15, 2067–2073 (2015).
Mleczko, M. J. et al. HfSe2 and ZrSe2: two-dimensional semiconductors with native high-k oxides. Sci. Adv. 3, e1700481 (2017).
Peimyoo, N. et al. Laser-writable high-κ dielectric for van der Waals nanoelectronics. Sci. Adv. 5, eaau0906 (2019).
Wu, J. X. et al. High electron mobility and quantum oscillations in non-encapsulated ultrathin semiconducting Bi2O2Se. Nat. Nanotechnol. 12, 530–535 (2017).
Chen, C. et al. Electronic structures and unusually robust bandgap in an ultrahigh-mobility layered oxide semiconductor, Bi2O2Se. Sci. Adv. 4, eaat8355 (2018).
Wu, D. et al. Thickness-dependent dielectric constant of few-layer In2Se3 nanoflakes. Nano Lett. 15, 8136–8140 (2015).
Lin, Z. et al. Solution-processable 2D semiconductors for high-performance large-area electronics. Nature 562, 254–258 (2018).
Chen, B. et al. Highly uniform carbon nanotube field-effect transistors and medium scale integrated circuits. Nano Lett. 16, 5120–5128 (2016).
Tan, C. W. et al. Wafer-scale growth of single-crystal 2D semiconductor on perovskite oxides for high-performance transistors. Nano Lett. 19, 2148–2153 (2019).
Kresse, G. & Hafner, J. Norm-conserving and ultrasoft pseudopotentials for first-row and transition-elements. J. Phys. Condens. Matter 6, 8245–8257 (1994).
Heyd, J., Scuseria, G. E. & Ernzerhof, M. Hybrid functionals based on a screened Coulomb potential. J. Chem. Phys. 118, 8207–8215 (2003).
Vydrov, O. A., Heyd, J., Krukau, A. V. & Scuseria, G. E. Importance of short-range versus long-range Hartree–Fock exchange for the performance of hybrid density functionals. J. Chem. Phys. 125, 074106 (2006).
Wu, X. et al. Quantitative measurements of nanoscale permittivity and conductivity using tuningfork-based microwave impedance microscopy. Rev. Sci. Instrum. 89, 043704 (2018).
Wu, J. X. et al. Chemical patterning of high-mobility semiconducting 2D Bi2O2Se crystals for integrated optoelectronic devices. Adv. Mater. 29, 1704060 (2017).
We thank G.F. Dong for her help and discussions in measuring dielectric properties. We acknowledge financial support from the National Natural Science Foundation of China (21733001, 21525310, 51672007 and 11974023) and the National Basic Research Program of China (2016YFA0200101). P.G. also acknowledges support from the Key Area R&D Program of Guangdong Province (2018B010109009) and the Key R&D Program of Guangdong Province (2018B030327001). J.Y. and K.L. were supported by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences (award no. DE-SC0019025).
The authors declare no competing interests.
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Li, T., Tu, T., Sun, Y. et al. A native oxide high-κ gate dielectric for two-dimensional electronics. Nat Electron 3, 473–478 (2020). https://doi.org/10.1038/s41928-020-0444-6
Nature Electronics (2020)