Title: Effects of Nitrogen on Amorphous Nitrogenated InGaZnO (a-IGZO:N) Thin Film Transistors
Authors: Liu, Po-Tsun
Chang, Chih-Hsiang
Fuh, Chur-Shyang
Liao, Yu-Tei
Sze, Simon M.
Department of Electronics Engineering and Institute of Electronics
Department of Photonics
Institute of Display
Keywords: a-IGZO;nitrogen;amorphous semiconductors;thin-film transistors (TFTs)
Issue Date: Oct-2016
Abstract: In this study, the role of nitrogen in the dc-sputtered amorphous indium gallium zinc oxide (a-IGZO):N are explored extensively with a series of nitrogen gas flow rates during IGZO film deposition. The amorphous film structure and the evolution of chemical bondings were confirmed by X-ray diffractometer and X-ray photoelectron spectroscopy spectra analysis. Also, electrical performance and reliability of a-IGZO: N thin-film transistors (TFTs) formed with different nitrogen gas flow rates were analyzed to study the effects of nitrogen on TFT devices. The device performance of a-IGZO: N TFTs can be enhanced with a proper nitrogen doping concentration. However, with excess nitrogen incorporation in the a-IGZO: N channel layer, both electric characteristic and reliability are degraded due to the extra creation of oxygen deficiencies in a-IGZO: N film and easy formation of unstable interface between gate insulator and channel layer, which were confirmed by low-frequency noise measurement. This potential issue of a-IGZO: N TFT characteristics can be effectively released by introducing a post-treatment on the surface of gate dielectric layer. The optimized electrical characteristics of a-IGZO: N TFT can exhibit a carrier mobility of 19.21 cm(2)/V . s, subthreshold swing of 0.26 V/decade and threshold voltage (V-th) of -0.74 V in this study.
URI: http://dx.doi.org/10.1109/JDT.2016.2585186
ISSN: 1551-319X
DOI: 10.1109/JDT.2016.2585186
Volume: 12
Issue: 10
Begin Page: 1070
End Page: 1077
Appears in Collections:Articles