Performance Investigation of Amorphous InGaZnO Flexible Thin-Film Transistors Deposited on PET Substrates

• Published in: Journal of display technology 2014-09, Vol.10 (9), p.792-796
• Main Authors: Lee, Hsin-Ying, Ye, Wan-Yi, Lin, Yung-Hao, Lee, Ching-Ting
• Format: Article
• Language: English
• Subjects: Channels; Cosputter; Deposition; flexible substrate; InGaZnO; Logic gates; Polyethylene terephthalate; polyethylene terephthalate (PET); Polyethylene terephthalates; Positron emission tomography; Radio frequencies; Radio frequency; Semiconductor devices; Substrates; Thin film transistors; thin-film transistors (TFTs); Threshold voltage; Transistors
• ISSN: 1551-319X; 1558-9323
• DOI: 10.1109/JDT.2014.2326883

Amorphous indium gallium zinc oxide (a-InGaZnO) flexible thin-film transistors (TFTs) were deposited on polyethylene terephthalate (PET) substrates at low temperature using a triple-targets magnetron radio frequency (RF) cosputter system. During the deposition of InGaZnO films, triple targets of In 2 O 3 target, Ga 2 O 3 target, and Zn target were simultaneously sputtered. By varying the mixing gas ratios, the Ar/O 2 ratio of 55 sccm/45 sccm was used as the sputtering gases to deposit the InGaZnO channel layer. The bottom-gate-type triple-targets InGaZnO flexible TFTs operated in n-type enhancement mode with a transconductance of 4.95×10 -5 S, a field-effect mobility of 57.2 cm 2 /V·s, an on/off ratio of 4.19×10 7 , a turn-on voltage of 0 V, a threshold voltage of 2.5 V, and a subthreshold swing of 0.23 V/decade, which were much better than those of the single InGaZnO target flexible TFTs.