Oxide semiconductor device on polymer substrates for wearable and implantable electronic systems
Flexible electronics
Abstract:
The next step to improve the user benefit of wearable devices is the integration of electronic functionality into everyday objects such as textiles, the attachment of electronics to the human body, and the fabrication of smart implantable devices. One possibility to fabricate imperceptible devices, compatible with the mechanical and electrical requirements of the envisioned wearables, is the combination of thin-film technology, novel oxide materials, and flexible substrates. Here, it is shown how In-Ga-Zn-O based thin-film transistors (TFTs) can be fabricated on plastic substrates. These TFTs are manufactured using a maximum process temperature of 150°C, exhibit a carrier mobility >10 cm2V-1s-1, and can be operated at low voltages.
The optimisation of the mechanical and electrical properties of single TFTs and the fabrication of integrated circuits enabled the realization of electronic systems for different applications. Examples are systems with extreme mechanical robustness such as transparent, highly bendable TFTs and sensors on a 1 µm thin parylene membrane for smart contact lenses, or TFTs with wavy surface layout to mimic the behaviour and stretchability of human skin. At the same time, high-speed circuits, able to operate in the Megahertz regime, and the fabrication of an entirely flexible radio demonstrate the electrical performance of oxide TFTs.