Flexible thin-film electronics could transform chip design

Flexible thin-film electronics could transform chip design
by Robert Schreiber
Berlin, Germany (SPX) Apr 26, 2024

The large semiconductor fabrication plants, or "foundries," are critical in the mass production of conventional silicon chips, a model that has proven highly successful. New research conducted by KU Leuven and imec indicates that this foundry model could be similarly effective for flexible, thin-film electronics, potentially enhancing innovation in this sector significantly.

Silicon semiconductors, often referred to as the 'oil' of the computer age, have underscored their value during the recent chip shortage crisis. However, a key limitation of conventional silicon chips is their lack of mechanical flexibility. Conversely, thin-film transistor (TFT) technology offers flexibility, opening up numerous potential applications including wearable healthcare devices, robotic interfaces, and flexible displays.

Despite the evolution of TFT technology, its application beyond smartphone, laptop, and smart TV displays has been limited. These displays use TFTs to control pixels individually, restricting the potential for broader application in flexible microchip design. Kris Myny, a professor at KU Leuven's Emerging technologies, Systems and Security unit and guest professor at imec, advocates for the adoption of a foundry business model in the thin-film electronics field to expand these applications.

"This field can benefit hugely from a foundry business model similar to that of the conventional chip industry," says Kris Myny.

In demonstrating the viability of this model, Myny's team designed a TFT-based microprocessor produced in two foundries, successfully testing both versions in their laboratory. The research, published in Nature, highlights the production of the MOS 6502 microprocessor-a key component in early Apple, Commodore, and Nintendo computers-on both amorphous indium-gallium-zinc-oxide and low-temperature polycrystalline silicon substrates.

The multi-project approach used in this study allowed for the simultaneous manufacturing of different chips on the same substrate, demonstrating that flexible chips can be designed and produced in a manner similar to conventional chips. This approach could particularly revolutionize medical applications, such as ultra-thin wearable patches for monitoring heart and muscle conditions, offering comfort comparable to a sticker.

"While the performance of the 6502 microprocessor is not on par with modern processors, this research underscores the potential for designing and manufacturing flexible chips in a multi-project approach," Myny concludes. "Our aim is not to compete with silicon-based chips but to foster and accelerate innovation in flexible, thin-film electronics."

Research Report:Multi-project wafers for flexible thin-film electronics by independent foundries