Effect of oxygen deficiency on electronic properties and local structure of amorphous tantalum oxide thin films

Journal Article · Sat Oct 15 00:00:00 EDT 2016 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2016.03.004· OSTI ID:22581628

Denny, Yus Rama ^[1]; Firmansyah, Teguh ^[2]; Oh, Suhk Kun ^[3]; Yang, Dong-Seok ^[4]; Heo, Sung; Chung, JaeGwan; Lee, Jae Cheol ^[5]

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1. Department of Physics Education, University of Sultan Ageng Tirtayasa, Banten 42435 (Indonesia)
2. Department of Electrical Engineering, University of Sultan Ageng Tirtayasa, Banten 42435 (Indonesia)
3. Department of Physics, Chungbuk National University, Cheongju 28644 (Korea, Republic of)
4. Department of Physics Education, Chungbuk National University, Cheongju 28644 (Korea, Republic of)
5. Analytical Engineering Center, Samsung Advanced Institute of Technology, Suwon 16678 (Korea, Republic of)

Highlights: • The effect of oxygen flow rate on electronic properties and local structure of tantalum oxide thin films was studied. • The oxygen deficiency induced the nonstoichiometric state a-TaOx. • A small peak at 1.97 eV above the valence band side appeared on nonstoichiometric Ta{sub 2}O{sub 5} thin films. • The oxygen flow rate can change the local electronic structure of tantalum oxide thin films. - Abstract: The dependence of electronic properties and local structure of tantalum oxide thin film on oxygen deficiency have been investigated by means of X-ray photoelectron spectroscopy (XPS), Reflection Electron Energy Loss Spectroscopy (REELS), and X-ray absorption spectroscopy (XAS). The XPS results showed that the oxygen flow rate change results in the appearance of features in the Ta 4f at the binding energies of 23.2 eV, 24.4 eV, 25.8, and 27.3 eV whose peaks are attributed to Ta{sup 1+}, Ta{sup 2+}, Ta{sup 3+}/Ta{sup 4+}, and Ta{sup 5+}, respectively. The presence of nonstoichiometric state from tantalum oxide (TaOx) thin films could be generated by the oxygen vacancies. In addition, XAS spectra manifested both the increase of coordination number of the first Ta-O shell and a considerable reduction of the Ta-O bond distance with the decrease of oxygen deficiency.

• OSTI ID: 22581628
• Journal Information: Materials Research Bulletin, Vol. 82; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTRA
ABSORPTION SPECTROSCOPY
AMORPHOUS STATE
BINDING ENERGY
BOND LENGTHS
COORDINATION NUMBER
ELECTRONIC STRUCTURE
ENERGY LOSSES
ENERGY-LOSS SPECTROSCOPY
FINE STRUCTURE
TANTALUM IONS
TANTALUM OXIDES
THIN FILMS
VACANCIES
X-RAY PHOTOELECTRON SPECTROSCOPY
X-RAY SPECTROSCOPY