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A single-crystalline native dielectric for two-dimensional semiconductors with an equivalent oxide thickness below 0.5 nm

Abstract

Scaling down the size of field-effect transistors in integrated circuits leads to higher speed, lower power consumption and increased integration density, but also results in short-channel effects. Transistors made using high-mobility two-dimensional (2D) semiconductor channels and ultrathin high-κ dielectrics can suppress this effect. However, it is difficult to integrate 2D semiconductors with dielectric layers that have an equivalent oxide thickness below 0.5 nm and low leakage current. Here we report the wafer-scale synthesis of β-Bi2SeO5—a single-crystalline native oxide with a dielectric constant of around 22—via the lithography-compatible ultraviolet-assisted intercalative oxidation of the high-mobility 2D semiconductor Bi2O2Se. We use the approach to create top-gated 2D transistors with sub-0.5-nm-equivalent-oxide-thickness dielectrics that exhibit leakage current below the low-power limit of 0.015 A cm−2 at a gate voltage of 1 V.

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Fig. 1: Intercalative oxidation of 2D Bi2O2Se for single-crystalline native oxide.
Fig. 2: UV-assisted controlled synthesis of 2D Bi2O2Se/β-Bi2SeO5 heterostructures.
Fig. 3: Dielectric properties of β-Bi2SeO5 single crystal.
Fig. 4: Sub-0.5-nm-EOT β-Bi2SeO5 dielectrics in 2D FETs.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

References

  1. International Roadmap for Devices and Systems (IEEE, 2021).

  2. 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).

    Article  Google Scholar 

  3. Liu, Y. et al. Promises and prospects of two-dimensional transistors. Nature 591, 43–53 (2021).

    Article  Google Scholar 

  4. Yan, R. H., Ourmazd, A. & Lee, K. F. Scaling the Si MOSFET: from bulk to SOI to bulk. IEEE Trans. Electron Devices 39, 1704–1710 (1992).

    Article  Google Scholar 

  5. Akinwande, D. et al. Graphene and two-dimensional materials for silicon technology. Nature 573, 507–518 (2019).

    Article  Google Scholar 

  6. Liu, C. et al. Two-dimensional materials for next-generation computing technologies. Nat. Nanotechnol. 15, 545–557 (2020).

    Article  Google Scholar 

  7. Shen, P.-C. et al. Ultralow contact resistance between semimetal and monolayer semiconductors. Nature 593, 211–217 (2021).

    Article  Google Scholar 

  8. Chang, C. et al. Recent progress on two-dimensional materials. Acta Phys. Chim. Sin. 37, 2108017 (2021).

    Article  Google Scholar 

  9. Illarionov, Y. Y. et al. Ultrathin calcium fluoride insulators for two-dimensional field-effect transistors. Nat. Electron. 2, 230–235 (2019).

    Article  Google Scholar 

  10. Das, S. et al. Transistors based on two-dimensional materials for future integrated circuits. Nat. Electron. 4, 786–799 (2021).

    Article  Google Scholar 

  11. Robertson, J. & Wallace, R. M. High-K materials and metal gates for CMOS applications. Mater. Sci. Eng. R 88, 1–41 (2015).

    Article  Google Scholar 

  12. Illarionov, Y. Y. et al. Insulators for 2D nanoelectronics: the gap to bridge. Nat. Commun. 11, 3385 (2020).

    Article  Google Scholar 

  13. Li, W. et al. Uniform and ultrathin high-κ gate dielectrics for two-dimensional electronic devices. Nat. Electron. 2, 563–571 (2019).

    Article  Google Scholar 

  14. Nichau, A. et al. Reduction of silicon dioxide interfacial layer to 4.6 Å EOT by Al remote scavenging in high-κ/metal gate stacks on Si. Microelectron. Eng. 109, 109–112 (2013).

    Article  Google Scholar 

  15. Britnell, L. et al. Electron tunneling through ultrathin boron nitride crystalline barriers. Nano Lett. 12, 1707–1710 (2012).

    Article  Google Scholar 

  16. Knoblocha, T. et al. The performance limits of hexagonal boron nitride as an insulator for scaled CMOS devices based on two-dimensional materials. Nat. Electron. 4, 98–108 (2021).

    Article  Google Scholar 

  17. Zhu, K. et al. The development of integrated circuits based on two-dimensional materials. Nat. Electron. 4, 775–785 (2021).

    Article  Google Scholar 

  18. Vexler, M. I. et al. A general simulation procedure for the electrical characteristics of metal-insulator-semiconductor tunnel structures. Semiconductors 47, 686–694 (2013).

    Article  Google Scholar 

  19. Li, T. et al. A native oxide high-κ gate dielectric for two-dimensional electronics. Nat. Electron. 3, 473–478 (2020).

    Article  Google Scholar 

  20. Li, T. & Peng, H. 2D Bi2O2Se: an emerging material platform for the next-generation electronic industry. Acc. Mater. Res. 2, 842–853 (2021).

    Article  Google Scholar 

  21. Zhu, H. et al. Remote plasma oxidation and atomic layer etching of MoS2. ACS Appl. Mater. Interfaces 8, 19119–19126 (2016).

    Article  Google Scholar 

  22. Zhang, L. et al. 2D atomic crystal molecular superlattices by soft plasma intercalation. Nat. Commun. 11, 5960 (2020).

    Article  Google Scholar 

  23. Song, S. H. et al. Bandgap widening of phase quilted, 2D MoS2 by oxidative intercalation. Adv. Mater. 27, 3152–3158 (2015).

    Article  Google Scholar 

  24. Yamamoto, M. et al. Self-limiting layer-by-layer oxidation of atomically thin WSe2. Nano Lett. 15, 2067–2073 (2015).

    Article  Google Scholar 

  25. Peimyoo, N. et al. Laser-writable high-k dielectric for van der Waals nanoelectronics. Sci. Adv. 5, eaau0906 (2019).

  26. Lai, S. et al. HfO2/HfS2 hybrid heterostructure fabricated via controllable chemical conversion of two-dimensional HfS2. Nanoscale 10, 18758–18766 (2018).

    Article  Google Scholar 

  27. Chamlagain, B. et al. Thermally oxidized two-dimensional TaS2 as a high-κ gate dielectric for MoS2 field-effect transistors. 2D Mater. 4, 31002 (2017).

    Article  Google Scholar 

  28. Mleczko, M. J. et al. HfSe2 and ZrSe2: two-dimensional semiconductors with native high-k oxides. Sci. Adv. 3, e1700481 (2017).

  29. Tu, T. et al. Uniform high-k amorphous native oxide synthesized by oxygen plasma for top-gated transistors. Nano Lett. 20, 7469–7475 (2020).

    Article  Google Scholar 

  30. Wu, J. et al. High electron mobility and quantum oscillations in non-encapsulated ultrathin semiconducting Bi2O2Se. Nat. Nanotechnol. 12, 530–535 (2017).

    Article  Google Scholar 

  31. Wei, Q. et al. Quasi-two-dimensional Se-terminated bismuth oxychalcogenide (Bi2O2Se). ACS Nano 13, 13439–13444 (2019).

    Article  Google Scholar 

  32. Dityatyev, O. A. et al. Phase equilibria in the Bi2TeO5–Bi2SeO5 system and a high temperature neutron powder diffraction study of Bi2SeO5. Solid State Sci. 6, 915–922 (2004).

    Article  Google Scholar 

  33. Wu, D. et al. Thickness-dependent dielectric constant of few-layer In2Se3 nanoflakes. Nano Lett. 15, 8136–8140 (2015).

    Article  Google Scholar 

  34. Ando, T. et al. CMOS compatible MIM decoupling capacitor with reliable sub-nm EOT high-k stacks for the 7 nm node and beyond. IEDM 16, 236–239 (2016).

    Google Scholar 

  35. Guha, S. et al. High-quality aluminum oxide gate dielectrics by ultra-high-vacuum reactive atomic-beam deposition. J. Appl. Phys. 90, 512 (2001).

    Article  Google Scholar 

  36. Gusev, E. P. et al. Ultrathin high-K metal oxides on silicon: processing, characterization and integration issues. Microelectron. Eng. 59, 341–349 (2001).

    Article  Google Scholar 

  37. Tsai, W. et al. Performance comparison of sub 1 nm sputtered TiN/HfO2 nMOS and pMOSFETs. IEDM 3, 311–314 (2003).

    Google Scholar 

Download references

Acknowledgements

We thank X. Wang and J. Pei for the kind help on the capacitance measurement of the metal–insulator–semiconductor heterostructure. We also thank D. Hu for his kind help in the contrast experiment of O3 oxidation with and without UV. We acknowledge Molecular Materials and Nanofabrication Laboratory (MMNL) in the College of Chemistry and Electron Microscopy Laboratory of Peking University for the use of instruments. We also acknowledge financial support from the National Natural Science Foundation of China (21733001, 21920102004, 11974023 and 52021006). H.P. acknowledges support from the Beijing National Laboratory for Molecular Sciences (BNLMS-CXTD-202001) and Tencent Foundation (The XPLORER PRIZE). P.G. acknowledges support from the Key Area R&D Program of Guangdong Province (2018B030327001 and 2018B010109009), and the ‘2011 Program’ from the Peking-Tsinghua-IOP Collaborative Innovation Center of Quantum Matter, Youth Innovation Promotion Association, CAS. J.Y. and K.L. were supported by Welch Foundation grant F-1814.

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Contributions

Under the direction of H.P., Y.Z. developed the controlled synthesis of single-crystalline β-Bi2SeO5 with the help of T.T. and C.Z. and fabricated the FET devices with sub-0.5-nm-EOT dielectric with the help of M.W., C.T. and Y.W. The MIM measurements for the dielectric constant was carried out by J.Y. under the supervision of K.L. The cross-sectional STEM measurements were performed by R.Z. under the direction of P.G. The top-view TEM, SAED and EDS characterizations were carried out by X.G. and Y.Z. The Bi2O2Se samples were supplied by C.T., M.Y. and Y.Z. The XRD measurements were performed by X.Z. The electron diffraction measurements were finished by X.G. The manuscript was written by H.P. and Y.Z. with input from K.L. and the other authors. The revision of the manuscript is finished by H.L., Y.Z. and H.P. All the work was supervised by H.P. All the authors contributed to the scientific planning and discussions.

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Correspondence to Hailin Peng.

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Nature Electronics thanks Tianyou Zhai and Zhixian Zhou for their contribution to the peer review of this work.

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Zhang, Y., Yu, J., Zhu, R. et al. A single-crystalline native dielectric for two-dimensional semiconductors with an equivalent oxide thickness below 0.5 nm. Nat Electron 5, 643–649 (2022). https://doi.org/10.1038/s41928-022-00824-9

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