1. Correlation between crystallinity and oxygen vacancy formation in In–Ga–Zn oxide
- Author
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Tomoki Hiramatsu, Motoki Nakashima, Noritaka Ishihara, Koji Dairiki, Masashi Tsubuku, Erumu Kikuchi, and Shunpei Yamazaki
- Subjects
010302 applied physics ,Materials science ,General Engineering ,Analytical chemistry ,Oxide ,General Physics and Astronomy ,Mineralogy ,chemistry.chemical_element ,02 engineering and technology ,Edge (geometry) ,021001 nanoscience & nanotechnology ,01 natural sciences ,Oxygen ,Crystal ,chemistry.chemical_compound ,Crystallinity ,chemistry ,0103 physical sciences ,Scanning transmission electron microscopy ,Grain boundary ,Electrical measurements ,sense organs ,0210 nano-technology - Abstract
We study the effect of indium–gallium–zinc oxide (IGZO) crystallinity on oxygen vacancies that play an important role in the characteristics of IGZO-based devices. Optical and electrical measurements revealed that deep defect levels due to oxygen vacancies are largely eliminated in c-axis-aligned crystal IGZO (CAAC-IGZO), which has increased crystallinity without clear grain boundaries. In this study, the correlation between crystallinity and oxygen vacancy formation has been examined by first-principles calculations to investigate the effect of oxygen vacancies in IGZO. Furthermore, the likelihood of oxygen vacancy formation at an edge portion of single-crystal IGZO has been verified by observations of oxygen atoms at the edge region of the IGZO film by annular bright-field scanning transmission electron microscopy (ABF-STEM). Experimental and calculation results show that the high crystallinity of IGZO is important for the inhibition of oxygen vacancies.
- Published
- 2016