Characteristics of ZnO films prepared by atomic layer deposition for transparent electronic devices
Doo Hyong Lee1, Hee Soo Kim, Seung Jeong Noh
1Department of Applied Physics, Institute of Nanosensor and Biotechnology, Dankook University, 126 Jukjeon-Dong, Suji-Gu, Yongin 448-701, South Korea.
Abstract:
Recently, nanostructured zinc oxide (ZnO) for many different applications in micro- and opto-electronic devices has been studied intensively. However, its structural and electrical properties still require improvements for ZnO-based transparent electronics. In this study, we fabricated ZnO films (thicknesses from 30 to 70 nm) on glass substrates using atomic layer deposition (ALD) and investigated the film properties in relation with substrate temperatures. The processing window (thermal ALD window) of self-limiting growth was observed at 110-190 degrees C. In our thermal ALD window, the average growth rate of ZnO films was 0.26 nm/cycle, and the (002) orientation became dominant with increasing substrate temperatures. For all growth temperatures, ZnO films have shown n-type conductivity. At 170 degrees C, ZnO with good electrical properties of carrier concentration (1.3 x 10(19) cm(-3)), mobility (18 cm2/Vs), and resistivity (2.7 x 10(-2) omegacm) was successfully obtained.
