Overall
- Language
- English
- Conflict of Interest
- In relation to this article, we declare that there is no conflict of interest.
- Publication history
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Received March 11, 2025
Revised August 8, 2025
Accepted September 9, 2025
Available online January 25, 2026
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This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0) which permits
unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Most Cited
A Study of Chlorine Incorporation in Amorphous In–Ga–Zn–O Thin‑Film Transistors by Soaking in NaCl Solution
https://doi.org/10.1007/s11814-025-00554-6
Abstract
We investigated the influence of chlorine incorporation on solution-processed amorphous indium–gallium–zinc oxide
(a-IGZO) thin-film transistors (TFTs). During the TFT fabrication process, materials inevitably interact with unintended
elements. Notably, chlorine is an essential component in various stages of TFT fabrication, including as a precursor for
metal oxide deposition and as a dry etching gas, making exposure to chlorine nearly unavoidable. Therefore, understanding
chlorine’s role in affecting the electrical and material properties of TFT devices is crucial. In this study, we immersed a-IGZO
films in NaCl solution to incorporate chlorine into the films. X-ray photoelectron spectroscopy (XPS) analysis revealed that
chlorine formed bonds with metals and increased oxygen vacancies (Vo), while the metal–oxide (M–O) bonding decreased.
These structural modifications led to a degradation in IGZO’s electrical performance. Compared to pristine TFTs, the saturation
mobility of a-IGZO TFTs soaked in NaCl solution decreased from 1.42 to 0.28 cm2/V·s, while the subthreshold slope increased from 0.40 to 0.79 V/dec, indicating higher defect density. X-ray diffraction (XRD) results confirmed that soaking in NaCl solution did not alter the crystallinity of the a-IGZO film. In addition, we found that chlorine incorporation rarely occurred in IGZO films deposited via the sputtering process. These findings highlight the need for careful control of chlorine exposure during fabrication to ensure the desired electrical performance of a-IGZO TFTs.
