[paper] Flexible TFT Electronics

Hikmet Çeliker, Wim Dehaene and Kris Myny

Multi-project wafers for flexible thin-film electronics by independent foundries.

Nature (2024)

DOI: 10.1038/s41586-024-07306-2

1. ESAT, KU Leuven, Leuven, Belgium
2. imec, Leuven, Belgium

Abstract: Flexible and large-area electronics rely on thin-film transistors (TFTs) to make displays large-area image sensors, microprocessors, wearable healthcare patches, digital microfluidics, and more. Although silicon-based complementary metal–oxide–semiconductor (CMOS) chips are manufactured using several dies on a single wafer and the multi-project wafer concept enables the aggregation of various CMOS chip designs within the same die, TFT fabrication is currently lacking a fully verified, universal design approach. This increases the cost and complexity of manufacturing TFT-based flexible electronics, slowing down their integration into more mature applications and limiting the design complexity achievable by foundries. Here we show a stable and high-yield TFT platform for the fabless manufacturing of two mainstream TFT technologies, wafer-based amorphous indium–gallium–zinc oxide and panel-based low-temperature polycrystalline silicon, two key TFT technologies applicable to flexible substrates. We have designed the iconic 6502 microprocessor in both technologies as a use case to demonstrate and expand the multi-project wafer approach. Enabling the foundry model for TFTs, as an analogy of silicon CMOS technologies, can accelerate the growth and development of applications and technologies based on these devices.

FIG:  Photograph of all three chips at once: the vintage WDC 65C02 in a 40-pin DIP package (left), the flex LTPS 6502 (middle) and the flex IGZO 6502 (right)

Acknowledgements: We thank PanelSemi (a system-on-film foundry service provider in Taiwan) for providing LTPS panels and Pragmatic for providing IGZO wafers as a verification of our designs, using their foundry-mode panel and wafer delivery services. Part of this work has received funding under the Horizon Europe programme from the European Research Council under grant agreement no. 101088591 ‘ORISON project’. Views and opinions expressed are, however, those of the authors only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them.

[C4P] FLEPS 2022

Call for Papers

The IEEE International Conference on Flexible, Printable Sensors and Systems (FLEPS 2022) will be held in Vienna, Austria.

IEEE FLEPS 2022 is intended to provide a forum for research scientists, engineers, and practitioners throughout the world to present their latest research findings, ideas, and applications in the area of Flexible and Printable Sensors and Systems.

Topics of Interest

• Organic/Inorganic Electronic Sensors
• Emerging Materials for Flexible and Printable Systems
• Manufacturing Techniques
• High-throughput Printable Electronics
• Hybrid Flexible Sensors and Electronics
• Stretchable/Shrinkable Sensors and Electronics
• Soft/Smart Wearable and Implantable Sensing Systems
• Disposable/Reusable Sensors and Electronics
• Printed Large-Area Sensors and Systems
• Flexible or Printed Active and Passive Components (e.g. actuators, printed energy devices, smart labels, RFID etc.)
• Emerging applications of Flexible Electronics inc. IoT, smart cities etc.
• Simulation and Modelling
• Flexible/Printable Electronics in context with Circular Economy and green electronics

Publication of Papers: Presented papers will be included in the Proceedings of IEEE FLEPS 2022 and in IEEE Xplore pending author requirements being met. Authors may submit an extended IEEE FLEPS 2022 papers to the Special IEEE FLEX Journal Issue.

Exhibition & Patron Opportunities: The Conference exhibit area will provide your company or organization with the opportunity to inform and display your latest products, services, equipment, books, journals, and publications to attendees from around the world.

For further information, contact Coral Miller at Conference Catalysts, LLC.

OFETs Compact Modeling

Advances in Compact Modeling of Organic Field-Effect Transistors

Sungyeop Jung¹, Member, IEEE, Yvan Bonnassieux², Gilles Horowitz², Sungjune Jung¹, Member, IEEE, Benjamin Iñiguez³, Fellow, IEEE, and Chang-Hyun Kim⁴, Senior Member, IEEE

IEEE J-EDS (Early Access)

DOI: 10.1109/JEDS.2020.3020312

¹Future IT Innovation Laboratory and Department of Creative IT Engineering, Pohang University of Science and Technology, Pohang 37673, South Korea.
²LPICM, Ecole Polytechinque, CNRS, 91128 Palaiseau, France.

³DEEEA, Universitat Rovira i Virgili, Tarragona 43007, Spain.

⁴Department of Electronic Engineering, Gachon University, Seongnam 13120, South Korea

Abstract: In this review, recent advances in compact modeling of organic field-effect transistors (OFETs) are presented. Despite the inherent strength for printed flexible electronics and the extremely aggressive research conducted over more than three decades, the OFET technology still seems to remain at a relatively low technological readiness level. Among various possible reasons for that, the lack of a standard compact model, which effectively bridges the device- and system-level development, is clearly one of the most critical issues. This paper broadly discusses the essential requirements, up-to-date progresses, and imminent challenges for the OFET compact device modeling toward a universal, physically valid, and applicable description of this fast-developing technology.

Figure (a) Cross-sectional illustration and (b) circuit diagram with multi-component overlap capacitances of the printed 3-D organic complementary inverter, and (c) measured and simulated transient output voltage of an 11-stage ring oscillator.