Influence of channel layer thickness on the electrical performances of inkjet-printed In-Ga-Zn oxide thin-film transistors
Author
Wang, Y.
Sun, X. W.
Goh, G. K. L.
Demir, Hilmi Volkan
Yu, H. Y.
Date
2010-12-10Source Title
IEEE Transactions on Electron Devices
Print ISSN
0018-9383
Publisher
IEEE
Volume
58
Issue
2
Pages
480 - 485
Language
English
Type
ArticleItem Usage Stats
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Abstract
Inkjet-printed In-Ga-Zn oxide (IGZO) thin-film transistors (TFTs) with bottom-gate bottom-contact device architecture are studied in this paper. The impact of the IGZO film thickness on the performance of TFTs is investigated. The threshold voltage, field-effect mobility, on and off drain current, and subthreshold swing are strongly affected by the thickness of the IGZO film. With the increase in film thickness, the threshold voltage shifted from positive to negative, which is related to the depletion layer formed by the oxygen absorbed on the surface. The field-effect mobility is affected by the film surface roughness, which is thickness dependent. Our results show that there is an optimum IGZO thickness, which ensures the best TFT electrical performance. The best result is from a 55-nm-thick IGZO TFT, which showed a field-effect mobility in the saturation region of 1.41 cm(2)/V . s, a threshold voltage of 1 V, a drain current on/off ratio of approximately 4.3 x 10(7), a subthreshold swing of 384 mV/dec, and an off-current level lower than 1 pA.
Keywords
Film thicknessIn-ga-zn Oxide (igzo)
Inkjet printing
Thin-film transistors (tfts)
Semiconductors
Electronics
Fabrication
Polymer