am501817y_si_001.pdf (258.54 kB)

Damage-Free Back Channel Wet-Etch Process in Amorphous Indium–Zinc-Oxide Thin-Film Transistors Using a Carbon-Nanofilm Barrier Layer

Download (258.54 kB)
journal contribution
posted on 23.07.2014 by Dongxiang Luo, Mingjie Zhao, Miao Xu, Min Li, Zikai Chen, Lang Wang, Jianhua Zou, Hong Tao, Lei Wang, Junbiao Peng
Amorphous indium–zinc-oxide thin film transistors (IZO-TFTs) with damage-free back channel wet-etch (BCE) process were investigated. A carbon (C) nanofilm was inserted into the interface between IZO layer and source/drain (S/D) electrodes as a barrier layer. Transmittance electron microscope images revealed that the 3 nm-thick C nanofilm exhibited a good corrosion resistance to a commonly used H3PO4-based etchant and could be easily eliminated. The TFT device with a 3 nm-thick C barrier layer showed a saturated field effect mobility of 14.4 cm2 V–1 s–1, a subthreshold swing of 0.21 V/decade, an on-to-off current ratio of 8.3 × 1010, and a threshold voltage of 2.0 V. The favorable electrical performance of this kind of IZO-TFTs was due to the protection of the inserted C to IZO layer in the back-channel-etch process. Moreover, the low contact resistance of the devices was proved to be due to the graphitization of the C nanofilms after annealing. In addition, the hysteresis and thermal stress testing confirmed that the usage of C barrier nanofilms is an effective method to fabricate the damage-free BCE-type devices with high reliability.