title: Influence of source and drain contacts on the properties of indium-gallium-zinc-oxide thin-film transistors based on amorphous carbon nanofilm as barrier layer.
abstract: Amorphous indium-gallium-zinc-oxide thin film transistors (α-IGZO TFTs) with damage-free back channel wet-etch (BCE) process were achieved by introducing a carbon nanofilm as a barrier layer. We investigate the effects of different source-and-drain (S/D) materials on TFT performance. We find the TFT with Ti/C S/D electrodes exhibits a superior performance with higher output current, lower threshold voltage, and higher effective electron mobility compared to that of Mo/C S/D electrodes. Transmittance electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) are employed to analysis the interfacial interaction between S/D metal/C/α-IGZO layers. The results indicate that the better performance of TFTs with Ti/C electrodes should be attributed to the formations of Ti-C and Ti-O at the Ti/C-contact regions, which lead to a lower contact resistance, whereas Mo film is relatively stable and does not react easily with C nanofilm, resulting in a nonohmic contact behavior between Mo/C and α-IGZO layer. However, both kinds of α-IGZO TFTs show good stability under thermal bias stress, indicating that the inserted C nanofilms could avoid the impact on the α-IGZO channel regions during S/D electrodes formation. Finally, we successfully fabricated a high-definition active-matrix organic lighting emitting diode prototype driven by α-IGZO TFTs with Ti/C electrodes in a pilot line.
authors.affiliation: Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology , Guangzhou 510640, People's Republic of China.
authors.forename: Dongxiang
authors.initials: D
authors.lastname: Luo
authors.forename: Hua
authors.initials: H
authors.lastname: Xu
authors.forename: Mingjie
authors.initials: M
authors.lastname: Zhao
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Miao
authors.initials: M
authors.lastname: Xu
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zou
authors.forename: Hong
authors.initials: H
authors.lastname: Tao
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Junbiao
authors.initials: J
authors.lastname: Peng
keywords: amorphous-oxide semiconductor; carbon nanofilm; contacts; thin-film transistors