Study of In-Situ Hydrogen Plasma Treatment on InGaZnO with Atmospheric Pressure-Plasma Enhanced Chemical Vapor Deposition

In the past few years, thin film transistors have a wide range of applications on display technology, material selection and quality for its active layer is critical for device performance. Traditional amorphous silicon (a-Si) silicon has a lot of advantages such as good productivity, short process and low-cost. It also has a lot of shortcomings on these applications on TFTs such as photosensitivity, light degradation, and opacity, etc. The dispute of the material based on a-Si: H as an active layer in TFT is low field effect mobility (similar to 1 cm(2)/V.S) (M. Shur and M. Hack, J. Appl. Phys. 55, 3831 (1984)), photo sensitivity (low band gap about 1.7 V) and high deposition temperature (similar to 400 degrees C) (M. Shur, et al., J. Appl. Phys. 66, 3371 (1989); K. Khakzar and E. H. Lueder, IEEE Trans. Electron Devices 39, 1438 (1992)). Amorphous In-Ga-Zn-O (IGZO) had attracted attention that compared with the conventional a-Si: H, due to its good properties of simultaneously high/low conductivity with high visual transparency via doping level. Oxide-based semiconductors, such as ZnO (G. Adamopoulos, et al., Appl. Phys. Lett. 95, 133507-3 (2009); H.-C. Cheng, et al., Appl. Phys. Lett. 90, 012113-3 (2007)) and IGZO (C. J. Chiu, et al., Electron Device Letters, IEEE 31, 1245 (2010); L. Linfeng and P. Junbiao, IEEE Transactions on Electron Devices 58, 1452 (2011)) have been reported for the active channel layer. These oxide-based materials offer good electrical properties and high transparency for thin film transistors, its high transmittance can be applied to fabricate the full transparent TFT on flexible substrate. With In-situ hydrogen plasma treatment on a-IGZO produced by atmospheric pressure-plasma enhanced chemical vapor deposition (AP-PECVD), the material characteristics of a-IGZO is studied.