| Autor: |
Yusuke Nonaka, Yoichi Kurosawa, Yoshihiro Komatsu, Noritaka Ishihara, Masashi Oota, Motoki Nakashima, Takuya Hirohashi, Masahiro Takahashi, Shunpei Yamazaki, Toshimitsu Obonai, Yasuharu Hosaka, Junichi Koezuka, Jun Yamauchi |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 2014, Vol. 115 Issue 16, p163707-1-163707-5, 5p, 1 Chart, 6 Graphs |
| Abstrakt: |
In-Ga-Zn oxide (IGZO) is a next-generation semiconductor material seen as an alternative to silicon. Despite the importance of the controllability of characteristics and the reliability of devices, defects in IGZO have not been fully understood. We investigated defects in IGZO thin films using electron spin resonance (ESR) spectroscopy. In as-sputtered IGZO thin films, we observed an ESR signal which had a g-value of g=2.010, and the signal was found to disappear under thermal treatment. Annealing in a reductive atmosphere, such as N2 atmosphere, generated an ESR signal with g=1.932 in IGZO thin films. The temperature dependence of the latter signal suggests that the signal is induced by delocalized unpaired electrons (i.e., conduction electrons). In fact, a comparison between the conductivity and ESR signal intensity revealed that the signal's intensity is related to the number of conduction electrons in the IGZO thin film. The signal's intensity did not increase with oxygen vacancy alone but also with increases in both oxygen vacancy and hydrogen concentration. In addition, first-principle calculation suggests that the conduction electrons in IGZO may be generated by defects that occur when hydrogen atoms are inserted into oxygen vacancies. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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