The performance of silicon complementary metal–oxide–semiconductor integrated circuits can be enhanced through the monolithic three-dimensional integration of additional device layers. For example, silicon integrated circuits operate at low voltages (around 1 V) and high-voltage handling capabilities could be provided by monolithically integrating thin-film transistors. Here we show that high-voltage amorphous oxide semiconductor thin-film transistors can be integrated on top of a silicon integrated circuit containing 100-nm-node fin field-effect transistors using an in-air solution process. To solve the problem of voltage mismatch between these two device layers, we use a top Schottky, bottom ohmic contact structure to reduce the amorphous oxide semiconductor circuit switching voltage. These contacts are used to form Schottky-gated thin-film transistors and vertical thin-film diodes with excellent switching performance. As a result, we can create high-voltage amorphous oxide semiconductor circuits with switching voltages less than 1.2 V that can be directly integrated with silicon integrated circuits.
This is a preview of subscription content, access via your institution
Open Access articles citing this article.
2D transistors rapidly printed from the crystalline oxide skin of molten indium
npj 2D Materials and Applications Open Access 14 March 2022
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 per month
cancel any time
Subscribe to this journal
Receive 12 digital issues and online access to articles
$119.00 per year
only $9.92 per issue
Rent or buy this article
Get just this article for as long as you need it
Prices may be subject to local taxes which are calculated during checkout
The data that support the plots within this paper and other findings of this study are available from the corresponding author on reasonable request.
Mack, C. A. Fifty years of Moore’s law. IEEE Trans. Semicond. Manuf. 24, 202–207 (2011).
Salahuddin, S., Ni, K. & Datta, S. The era of hyper-scaling in electronics. Nat. Electron. 1, 442–450 (2018).
Peercy, P. S. The drive to miniaturization. Nature 406, 1023–1026 (2000).
Tummala, R. R. Moore’s law meets its match. IEEE Spectr. 43, 44–49 (2006).
Katti, G. et al. 3D stacked ICs using Cu TSVs and die to wafer hybrid collective bonding. In 2009 IEEE International Electron Devices Meeting (IEDM) 14.4 (IEEE, 2009).
Ko, C.-T. & Chen, K.-N. Wafer-level bonding/stacking technology for 3D integration. Microelectron. Reliab. 50, 481–488 (2010).
Batude, P. et al. 3DVLSI with CoolCube process: an alternative path to scaling. In 2015 Symposium on VLSI Technology T48–T49 (IEEE, 2015).
Sedky, S. Experimental determination of the maximum post-process annealing temperature for standard CMOS wafers. IEEE Trans. Electron Devices 48, 9 (2001).
Thomas, S. R., Pattanasattayavong, P. & Anthopoulos, T. D. Solution-processable metal oxide semiconductors for thin-film transistor applications. Chem. Soc. Rev. 42, 6910–6923 (2013).
Garlapati, S. K. et al. Printed electronics based on inorganic semiconductors: from processes and materials to devices. Adv. Mater. 30, 1707600 (2018).
Xu, W., Li, H., Xu, J.-B. & Wang, L. Recent advances of solution-processed metal oxide thin-film transistors. ACS Appl. Mater. Interfaces 10, 25878–25901 (2018).
Petti, L. et al. Metal oxide semiconductor thin-film transistors for flexible electronics. Appl. Phys. Rev. 3, 021303 (2016).
Liu, A., Zhu, H., Sun, H., Xu, Y. & Noh, Y.-Y. Solution processed metal oxide high-κ dielectrics for emerging transistors and circuits. Adv. Mater. 30, 1706364 (2018).
Marinkovic, M. et al. 14-1: Large-area processing of solution type metal-oxide in TFT backplanes and integration in highly stable OLED displays. SID Symp. Dig. Tech. Pap. 48, 169–172 (2017).
Hsueh, F.-K. et al. First fully functionalized monolithic 3D+IoT chip with 0.5 V light-electricity power management, 6.8 GHz wireless-communication VCO, and 4-layer vertical ReRAM. In 2016 IEEE International Electron Devices Meeting (IEDM) 2.3.1–2.3.4 (IEEE, 2016).
Shulaker, M. M. et al. Three-dimensional integration of nanotechnologies for computing and data storage on a single chip. Nature 547, 74–78 (2017).
Onuki, T. et al. Embedded memory and ARM Cortex-M0 core using 60-nm c-axis aligned crystalline indium–gallium–zinc oxide FET integrated with 65-nm Si CMOS. IEEE J. Solid-State Circuits 52, 925–932 (2017).
Sunamura, H. et al. Enhanced drivability of high-Vbd dual-oxide-based complementary BEOL-FETs for compact on-chip pre-driver applications. In 2014 Symposium on VLSI Technology: Digest of Technical Papers (IEEE, 2014).
Kaneko, K. et al. Operation of functional circuit elements using BEOL-transistor with InGaZnO channel for on-chip high/low voltage bridging I/Os and high-current switches. 2012 Symposium on VLSI Technology 123–124 (IEEE, 2012).
Yu, M.-J., Lin, R.-P., Chang, Y.-H. & Hou, T.-H. High-voltage amorphous InGaZnO TFT with Al2O3 high-k dielectric for low-temperature monolithic 3-D integration. IEEE Trans. Electron Devices 63, 3944–3949 (2016).
Van Breussegem, T. & Steyaert, M. CMOS Integrated Capacitive DC-DC Converters (Springer, 2013).
Kim, B. et al. Highly reliable depletion-mode a-IGZO TFT gate driver circuits for high-frequency display applications under light illumination. IEEE Electron Device Lett. 33, 528–530 (2012).
Shabanpour, R. et al. A fully integrated audio amplifier in flexible a-IGZO TFT technology for printed piezoelectric loudspeakers. In 2015 European Conference on Circuit Theory and Design (ECCTD) (IEEE, 2015).
Simicic, M., Hellings, G., Chen, S.-H., Myny, K. & Linten, D. ESD study on a-IGZO TFT device architectures. In 2018 40th Electrical Overstress/Electrostatic Discharge Symposium (EOSESD) 9A.3 (IEEE, 2018).
Kawamura, T. et al. Oxide TFT rectifier achieving 13.56-MHz wireless operation. IEEE Trans. Electron Devices 59, 3002–3008 (2012).
Yang, C.-C. et al. Footprint-efficient and power-saving monolithic IoT 3D+IC constructed by BEOL-compatible sub-10nm high aspect ratio (AR>7) single-grained Si FinFETs with record high Ion of 0.38 mA/μm and steep-swing of 65 mV/dec. and Ion/Ioff ratio of 8. In 2016 IEEE International Electron Devices Meeting (IEDM) 9.1.1–9.1.4 (IEEE, 2016).
Shulaker, M. M. et al. Monolithic 3D integration of logic and memory: carbon nanotube FETs, resistive RAM, and silicon FETs. In 2014 IEEE International Electron Devices Meeting 27.4.1–27.4.4 (IEEE, 2014).
Myny, K. The development of flexible integrated circuits based on thin-film transistors. Nat. Electron. 1, 30–39 (2018).
Son, Y., Liao, A. & Peterson, R. L. Effect of relative humidity and preannealing temperature on spin-coated zinc tin oxide films made via the metal–organic decomposition route. J. Mater. Chem. C 5, 8071–8081 (2017).
Brunet, L. et al. Breakthroughs in 3D sequential technology. In 2018 IEEE International Electron Devices Meeting (IEDM) 7.2.1–7.2.4 (IEEE, 2018).
Schlupp, P., Schein, F.-L., von Wenckstern, H. & Grundmann, M. All amorphous oxide bipolar heterojunction diodes from abundant metals. Adv. Electron. Mater. 1, 1400023 (2015).
Hu, W. & Peterson, R. L. Molybdenum as a contact material in zinc tin oxide thin film transistors. Appl. Phys. Lett. 104, 192105 (2014).
Fortunato, E., Barquinha, P. & Martins, R. Oxide semiconductor thin-film transistors: a review of recent advances. Adv. Mater. 24, 2945–2986 (2012).
Yu, X., Marks, T. J. & Facchetti, A. Metal oxides for optoelectronic applications. Nat. Mater. 15, 383–396 (2016).
Liu, A. et al. Redox chloride elimination reaction: facile solution route for indium-free, low-voltage, and high-performance transistors. Adv. Electron. Mater. 3, 1600513 (2017).
Yang, C.-C. et al. Location-controlled-grain technique for monolithic 3D BEOL FinFET circuits. In 2018 IEEE International Electron Devices Meeting (IEDM) 11.3.1–11.3.4 (IEEE, 2018).
Banger, K. K. et al. Low-temperature, high-performance solution-processed metal oxide thin-film transistors formed by a ‘sol–gel on chip’ process. Nat. Mater. 10, 45–50 (2011).
Kim, Y.-H. et al. Flexible metal-oxide devices made by room-temperature photochemical activation of sol–gel films. Nature 489, 128–132 (2012).
Waldrop, M. M. The chips are down for Moore’s law. Nature 530, 144–147 (2016).
Zhang, J. et al. Flexible indium–gallium–zinc–oxide Schottky diode operating beyond 2.45 GHz. Nat. Commun. 6, 7561 (2015).
Chasin, A. et al. An integrated a-IGZO UHF energy harvester for passive RFID tags. IEEE Trans. Electron Devices 61, 3289–3295 (2014).
Wang, N. et al. ESD characterisation of a-IGZO TFTs on Si and foil substrates. In 2017 47th European Solid-State Device Research Conference (ESSDERC) 276–279 (IEEE, 2017).
Li, Y. et al. A ferroelectric thin film transistor based on annealing-free HfZrO film. IEEE J. Electron Devices Soc. 5, 378–383 (2017).
Münzenrieder, N. et al. Flexible double gate a-IGZO TFT fabricated on free standing polyimide foil. Solid-State Electron. 84, 198–204 (2013).
Wang, Z., Nayak, P. K., Caraveo-Frescas, J. A. & Alshareef, H. N. Recent developments in p-type oxide semiconductor materials and devices. Adv. Mater. 28, 3831–3892 (2016).
Chi, L.-J., Yu, M.-J., Chang, Y.-H. & Hou, T.-H. 1-V full-swing depletion-load a-In–Ga–Zn–O inverters for back-end-of-line compatible 3D integration. IEEE Electron Device Lett. 37, 441–444 (2016).
Han, S. & Lee, S. Y. Full swing depletion-load inverter with amorphous SiZnSnO thin film transistors. Phys. Status Solidi A 214, 1600469 (2017).
Klüpfel, F. J., Holtz, A., Schein, F. L., von Wenckstern, H. & Grundmann, M. All-oxide inverters based on ZnO channel JFETs with amorphous ZnCo2O4 gates. IEEE Trans. Electron Devices 62, 4004–4008 (2015).
Dang, G. T., Kawaharamura, T., Furuta, M. & Allen, M. W. Zinc tin oxide metal semiconductor field effect transistors and their improvement under negative bias (illumination) temperature stress. Appl. Phys. Lett. 110, 073502 (2017).
Frenzel, H. et al. Recent progress on ZnO-based metal–semiconductor field-effect transistors and their application in transparent integrated circuits. Adv. Mater. 22, 5332–5349 (2010).
Vogt, S., von Wenckstern, H. & Grundmann, M. MESFETs and inverters based on amorphous zinc-tin-oxide thin films prepared at room temperature. Appl. Phys. Lett. 113, 133501 (2018).
Lahr, O. et al. Full-swing, high-gain inverters based on ZnSnO JFETs and MESFETs. IEEE Trans. Electron Devices 66, 3376–3381 (2019).
Son, Y. & Peterson, R. L. Exploiting in situ redox and diffusion of molybdenum to enable thin-film circuitry for low-cost wireless energy harvesting. Adv. Funct. Mater. 29, 1806002 (2019).
Semple, J., Georgiadou, D. G., Wyatt-Moon, G., Gelinck, G. & Anthopoulos, T. D. Flexible diodes for radio frequency (RF) electronics: a materials perspective. Semicond. Sci. Technol. 32, 123002 (2017).
Cai, W. et al. Low-voltage, flexible InGaZnO thin-film transistors gated with solution-processed, ultra-thin AlxOy. IEEE Electron Device Lett. 40, 36–39 (2019).
Wang, Y. et al. Amorphous-InGaZnO thin-film transistors operating beyond 1 GHz achieved by optimizing the channel and gate dimensions. IEEE Trans. Electron Devices 65, 1377–1382 (2018).
Chasin, A. et al. High-performance a-In-Ga-Zn-O Schottky diode with oxygen-treated metal contacts. Appl. Phys. Lett. 101, 113505 (2012).
Son, Y., Li, J. & Peterson, R. L. In situ chemical modification of Schottky barrier in solution-processed zinc tin oxide diode. ACS Appl. Mater. Interfaces 8, 23801–23809 (2016).
Flynn, B. T., Oleksak, R. P., Thevuthasan, S. & Herman, G. S. Interfacial chemistry-induced modulation of Schottky barrier heights: in situ measurements of the Pt–amorphous indium gallium zinc oxide interface using x-ray photoelectron spectroscopy. ACS Appl. Mater. Interfaces 10, 4333–4340 (2018).
Schultz, T. Influence of oxygen deficiency on the rectifying behavior of transparent-semiconducting-oxide-metal ionterfaces. Phys. Rev. Appl 9, 064001 (2018).
Hyland, A. M., Makin, R. A., Durbin, S. M. & Allen, M. W. Giant improvement in the rectifying performance of oxidized Schottky contacts to ZnO. J. Appl. Phys. 121, 024501 (2017).
Kumar Barik, U., Srinivasan, S., Nagendra, C. L. & Subrahmanyam, A. Electrical and optical properties of reactive DC magnetron sputtered silver oxide thin films: role of oxygen. Thin Solid Films 429, 129–134 (2003).
White, M. S., Olson, D. C., Shaheen, S. E., Kopidakis, N. & Ginley, D. S. Inverted bulk-heterojunction organic photovoltaic device using a solution-derived ZnO underlayer. Appl. Phys. Lett. 89, 143517 (2006).
Werner, J. H. & Güttler, H. H. Barrier inhomogeneities at Schottky contacts. J. Appl. Phys. 69, 1522 (1991).
Türüt, A., Bati, B., Kökçe, A., Sağlam, M. & Yalçin, N. The bias-dependence change of barrier height of Schottky diodes under forward bias by including the series resistance effect. Phys. Scr. 53, 118 (1996).
Fain, S. & McDavid, J. Work-function variation with alloy composition: Ag-Au. Phys. Rev. B 9, 5099–5107 (1974).
Tsui, B.-Y. & Huang, C.-F. Wide range work function modulation of binary alloys for MOSFET application. IEEE Electron Device Lett. 24, 153–155 (2003).
Haynes, W. M. (ed) Electron work function of the elements. In CRC Handbook of Chemistry and Physics 97th edn, Internet Version 2017 (CRC–Taylor & Francis, 2017).
We thank G. A. Torres Sevilla and M. M. Hussain of King Abdullah University of Science and Technology for providing the silicon CMOS samples. We also gratefully acknowledge the contributions of W. Hu, J. Li and J. Miller to TFT fabrication. This work was supported by SPAWAR through DARPA Young Faculty Award N66001-14-1-4046 under D. Green and Y.-K. Chen. Any opinions, findings, conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of DARPA or SPAWAR. Y.S. was supported in part by the Kwanjeong Educational Foundation. Portions of the work reported here were performed in the Lurie Nanofabrication Facility and Michigan Center for Materials Characterization, which are supported by the University of Michigan’s College of Engineering.
The authors declare no competing interests.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary Sections 1–10, Supplementary Figs. 1–10 and Supplementary Tables 1–5.
Rights and permissions
About this article
Cite this article
Son, Y., Frost, B., Zhao, Y. et al. Monolithic integration of high-voltage thin-film electronics on low-voltage integrated circuits using a solution process. Nat Electron 2, 540–548 (2019). https://doi.org/10.1038/s41928-019-0316-0
This article is cited by
2D transistors rapidly printed from the crystalline oxide skin of molten indium
npj 2D Materials and Applications (2022)
Analysis of the valence state of tin in ZnSnOx thin-film transistors
Journal of Materials Science: Materials in Electronics (2022)
p-/n-Type modulation of 2D transition metal dichalcogenides for electronic and optoelectronic devices
Nano Research (2022)
100 GHz zinc oxide Schottky diodes processed from solution on a wafer scale
Nature Electronics (2020)
Adding a new layer to ‘more than Moore’
Nature Electronics (2019)