As the complexity of flexible electronic devices such as displays and sensors has increased, new plastic-compatible manufacturing methods are becoming necessary to produce high-yield, low-defect flexible circuits. While solution-processed methods such as printing can be used to fabricate circuits on low-temperature substrates, printing is not always a feasible option to realize complex, high-density circuits with small devices. In particular, highresolution display applications typically require single-micron feature sizes and excellent uniformity over large-area substrates. For these applications, more precise fabrication techniques such as photolithography are required. However, due to the poor dimensional stability of polymers, even low-temperature processes such as soft bakes during lithography can alter the substrate dimensions. The problem of dimensional stability can be overcome by attaching the polymer film to a rigid carrier during device fabrication, then releasing the polymer substrate with the fully fabricated device layer on top. For this reason, the separation of polymer films from rigid carriers remains a crucial step in creating next-generation flexible electronics. In this talk, we will discuss a large-area, high-throughput photonic lift-off (PLO) process to rapidly separate polymer films from rigid carriers. PLO uses broadband light (200 nm — 1100 nm) from a flashlamp to lift off a polymer film from a rigid carrier coated with a light-absorbing layer (LAL), where the polymer film may contain functional devices [1]. Compared to a raster process such as excimer laser lift-off, the PLO process is advantageous as it can enable large area lift-off (150 mm x 75 mm) in one flash of light lasting between 100- 200 us, thus enabling higher throughput. Furthermore, the LAL prevents direct illumination of the polymer substrate during lift-off and facilitates cleaner lift-off without polymer ashing. The LAL also makes PLO a polymer-agnostic process, enabling lift-off of a wide range of polymers. We will discuss our recent work fabricating flexible thin-film transistors (TFTs) using PLO [2]. Polyimide with a low coefficient of thermal expansion (CTE) was used to minimize residual film stress. Indium zinc oxide (IZO) TFTs were fabricated on the polyimide films and subsequently released from the carrier using PLO. The released devices demonstrated no significant changes after the PLO process, yielding a mobility of ~3 cm“V_s__ before and after liftoff. The flexible TFTs were robust to bending stress, showing no notable decrease in mobility while bent with a 10 mm radius of curvature. When combined with the ability to successfully separate the PI from the carrier, the low-CTE PI creates a robust fabrication platform for flexible electronics that allows conventional patterning and deposition techniques to be used on a plastic substrate while maintaining dimensional stability with processing temperatures up to 380 °C. A 3D finite element model indicates that the polymer/LAL interface reaches above 800 °C during PLO, but the top surface of the PI remains below 120 °C. The model shows that the maximum temperature at the device layer during PLO is strongly impacted by the thickness and material properties of the polymer film, highlighting the value of the model to guide PLO device design. This work demonstrates the feasibility of PLO to successfully release polyimide substrates containing flexible electronic devices from glass carriers after withstanding conventional lithographic processing methods. [1] R. Hendriks and K. A. Schroder, “Method for performing delamination of a polymer film. U.S. Patent 10,011,104.,” U.S. Patent 10,011,104, Jul. 03, 2018 [2] A. M. Weidling, V. S. Turkani, V. Akhavan, K. A. Schroder, and S. L. Swisher, “Large-Area Photonic Lift-off Process for Flexible Thin-Film Transistors,” in press.

Large-Area Photonic Lift-off Process for Flexible Thin-Film Transistors

Metal oxides (e.g., In2O3, InZnO) have been demonstrated to be excellent materials for flexible electronics. Solution-processed methods offer a cost-effective and high uniformity route to deposit the metal oxides on a variety of substrates. However, post-processing is often necessary and it becomes a challenge on plastic substrates. Here, we explore photonic curing to process the semiconductor material without substantially heating the plastic substrate.

Photonic Curing: Rapid Thermal Processing of Oxide Thin-film Transistors on Plastic

Abstract Body: Metal oxide semiconductors such as indium gallium zinc oxide (IGZO) and indium zinc oxide (IZO) have received significant attention over the past few decades due to their desirable electrical and optical properties. Sol-gel techniques are commonly employed to deposit these materials because of the simplicity of the synthesis and the ability to easily tune the film composition. These sol-gel based oxide semiconductors often demonstrate high field-effect mobility even in the amorphous phase, but temperatures of at least 300 C are typically required to decompose the sol-gel and form high-quality semiconductor film. The desire to create high-quality flexible transistors on low-temperature plastic substrates has driven an investigation into alternative thermal processing methods for oxide semiconductors. One such option being explored is pulsed-light processing based on flashlamps, commonly known as photonic curing. Photonic curing offers advantages over conventional thermal processing methods such as ultra-short processing time and compatibility with low-temperature substrates. However, previous work on photonically cured thin-film transistors (TFTs) often results in significant heating of the entire substrate rather than just the thin film at the surface. In this talk, we will discuss our recent work using photonic curing to rapidly and effectively convert metal oxide sol-gels to realize high-quality TFTs. Sol-gel indium zinc oxide (IZO) based TFTs are photonically cured with efficient molybdenum gate absorbers using a xenon flashlamp (NovaCentrix PulseForge 1300) using intense white light delivering radiant energy up to 6 Jcm-2. Simulations indicate that the IZO film reaches a peak temperature of ~590 C while the back of the glass substrate stays near room temperature. This process yields TFTs with a field effect mobility above 20 cm2V-1s-1 and an IOn/IOff ratio approaching 108, which exceeds the performance of samples annealed at 500 C for 1 hr. We will discuss the requirements and design guidelines for photonic curing metal oxide semiconductors for high-performance TFT applications, focusing on the importance of effective gate absorbers and optimized pulse designs to efficiently and effectively cure the sol-gel films.

Photonic Curing of Solution-Processed Indium Zinc Oxide Thin-Film Transistors

Q: Oxide Semiconductor Devices, Defects and Transport

technical paper

After two years of virtual conferences, we're excited to host EMC 2022 in person at The Ohio State University in Columbus, Ohio. In addition to cutting-edge technical presentations given in multiple parallel sessions, opportunities to network with colleagues will be present throughout the conference. The size and format of the meeting makes networking easy, whether you have been coming to the conference for many years or are a first-time attendee.

EMC is coordinated with the Device Research Conference (DRC), which will be held the same week, from June 26-29. This recognizes the strong interaction between device and electronic materials research and provides fruitful exchange of information between attendees of both Conferences.

For information on the 80th Device Research Conference, please visit the DRC 2022 website.



EMC 2022

The Electronic Materials Conference (EMC) is the premier annual forum on the preparation, characterization and use of electronic materials. This year’s event will feature a plenary session, topical sessions, a poster session and more.

**Please use the button above to access the live recording.**
 
 Session Chair: Sarah Swisher

Session 7 - Thin Film Transistors

[![](https://assets.underline.io/uploads/markdown_image/1/image/985c8a40b04e56675221c8549975de3c.png)](https://drive.google.com/file/d/1B70nPIeeeqdG4UU70NlYXuKVOHLRuJEo/view?usp=sharing)

### ** History of DRC**
The Device Research Conference (DRC) began in the pre-transistor era with the 1942 establishment of the Conference on Electron Device Research (CEDR). Following William Shockley’s 1948 CEDR presentation of the transistor device, the Solid-State Device Research Conference (SSDRC) was established, with invitation-only attendance.

In the ensuing decades, many exciting firsts were presented at SSDRC, including the use of impurity diffusion in silicon and germanium, the first practical MOSFET, and the first lattice-matched heterojunction.

In 1969, under the leadership or Herbert Kroemer and Cal Quate, the CEDR and SSDRC merged into DRC. In 1970, attendance was opened to all, and the first DRAM (dynamic random-access memory), room temperature lasers, and first CCD (charge-coupled device) were reported—all in the same 1970 DRC meeting!

1976 saw the first official coordination of tandem meetings between DRC and the Electronic Materials Conference (EMC) to bring together the electronic materials and device communities—a custom which persists to this day. In 1991, DRC began publishing its digest with IEEE; they can all be found [here on IEEE Xplore](https://ieeexplore.ieee.org/xpl/conhome/1000199/all-proceedings). Throughout this period, DRC featured reports of many novel and record-setting devices, including the HEMT (High Electron Mobility Transistor), VCSEL (Vertical Cavity Surface Emitting Laser), HBT (Heterojunction Bipolar Transistor), and nanoscale MOSFETs.

In recent years, DRC has continued to be the world’s premier forum to present innovative semiconductor device research with work on organic thin film transistors, graphene and carbon nanotube transistors, and 2D materials all featuring prominently in the 1990s through to the present day. In 2017, we celebrated DRC’s 75th anniversary with special sessions and an [article in the Journal of the Electron Device Society](https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8168249&isnumber=8232486). DRC technical topics continue to evolve with emerging device trends such as memory devices, quantum devices, optoelectronics/photonics, and wide bandgap power devices to reflect the exciting work being done by a diverse community of device engineers around the globe.

Today, as we look forward to the next 75+ years of device innovation, DRC continues to lead the way in showcasing top-caliber research, facilitating vibrant discussion and debate and acting as a platform to nurture the next generation of device engineers. We welcome you to join us at the next DRC!

To learn more about DRC's history, please see [Aaron Franklin, Debdeep Jena and Deji Akinwande, "75 Years of the Device Research Conference—A History Worth Repeating," in IEEE Journal of the Electron Devices Society, vol. 6, pp. 116-120, 2018. doi: 10.1109/JEDS.2017.2780778](https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8168249&isnumber=8232486).

### **Topics**
* Biological Devices
* Devices for Extreme Conditions
* Heterogeneously Integrated Devices
* Memory Devices
* Modeling and Simulation of Devices
* Nanoscale and Vacuum Devices
* Optoelectronic and Optical Devices
* Other Emerging Devices
* Power Devices
* Quantum Devices
* RF and Terahertz Devices
* Spintronic and Magnetic Devices
* Thin-film Devices
* Wide-bandgap Devices
 
### **Invited Speakers**
* Patrick Fay, University of Notre Dame
* Susanne Hoffmann-Eifert, Peter Grünberg Institute
* Sanghyeon Kim, Korea Advanced Institute of Science and Technology
* Sriram Krishnamoorthy, University of California, Santa Barbara
* Mario Lanza, King Abdullah University of Science and Technology
* Xiuling Li, The University of Texas at Austin
* Marko Radosavljevic, Intel Corporation
* Siddharth Rajan, The Ohio State University
* Giordano Scappucci, Delft University of Technology
* Fisher Yu, University of Arkansas
* Wenjuan Zhu, University of Illinois at Urbana-Champaign




Registration is required to attend this event. If you have not already done so, please use the link below to register for a ticket to the conference:

https://www.mrs.org/drc-2022/registration

Registration Is Required

DRC 2022

DRC continues to be the world’s premier forum to present innovative semiconductor device research with work on organic thin film transistors, graphene and carbon nanotube transistors, and 2D materials all featuring prominently in the 1990s through to the present day. In 2017, we celebrated DRC’s 75th anniversary with special sessions and an article in the Journal of the Electron Device Society. 
DRC technical topics continue to evolve with emerging device trends such as memory devices, quantum devices, optoelectronics/photonics, and wide bandgap power devices to reflect the exciting work being done by a diverse community of device engineers around the globe.

PP: Oxide Thin Film Transistors

The Electronic Materials Conference (EMC) is the premier annual forum on the preparation, characterization and use of electronic materials. This year’s event will feature a plenary session, topical sessions, a poster session and more.

EMC is coordinated with the Device Research Conference (DRC), which will be held during the same week, from June 20-23. This recognizes the strong interaction between device and electronic materials research and provides fruitful exchange of information between attendees of both Conferences.

![](https://assets.underline.io/uploads/markdown_image/1/image/eb26c24a18d5d1030616afa4f993cf89.png)
	
<a href="https://www.mrs.org/docs/default-source/meetings-events/mrs-conference-services/2021/emc-2021/2021-emc-program-at-a-glance-6-16-21.pdf?sfvrsn=e39f950c_4">Latest Program-at-a-Glance</a>

<a href="https://drive.google.com/file/d/1eiS1ao4p83VNy8xgHs3Rls7gTQjx7Rc4/view?usp=sharing">Full Program with Abstracts</a>

Weidling Adam M.

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Presentations

Large-Area Photonic Lift-off Process for Flexible Thin-Film Transistors

Photonic Curing: Rapid Thermal Processing of Oxide Thin-film Transistors on Plastic

Photonic Curing of Solution-Processed Indium Zinc Oxide Thin-Film Transistors

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