High Mobility Thin Film Transistors with Transparent ZnO Channels

• Published in: Japanese Journal of Applied Physics Vol. 42; no. 4A; pp. L347 - L349
• Main Authors: Nishii, Junya, Hossain, Faruque M., Takagi, Shingo, Aita, Tetsuya, Saikusa, Koji, Ohmaki, Yuji, Ohkubo, Isao, Kishimoto, Shuya, Ohtomo, Akira, Fukumura, Tomoteru, Matsukura, Fumihiro, Ohno, Yuzo, Koinuma, Hideomi, Ohno, Hideo, Kawasaki, Masashi
• Format: Journal Article
• Language: English
• Published: 01.04.2003
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.42.L347

We have fabricated high performance ZnO thin film transistors (TFTs) using CaHfO x buffer layer between ZnO channel and amorphous silicon–nitride gate insulator. The TFT structure, dimensions, and materials set are identical to those of the commercial amorphous silicon (a-Si) TFTs in active matrix liquid crystal display, except for the channel and buffer layers replacing a-Si. The field effect mobility can be as high as 7 cm 2 ·V -1 ·s -1 for devices with maximum process temperature of 300°C. The process temperature can be reduced to 150°C without much degrading the performance, showing the possibility of the use of polymer substrate.