| AVS 56th International Symposium & Exhibition | |
| Thin Film | Friday Sessions |
| Session TF-FrM |
| Session: | Transparent Electronic Materials and Applications |
| Presenter: | Y. Sato, Aoyama Gakuin University, Japan |
| Authors: | Y. Sato, Aoyama Gakuin University, Japan K. Ishihara, Aoyama Gakuin University, Japan N. Oka, Aoyama Gakuin University, Japan Y. Shigesato, Aoyama Gakuin University, Japan |
| Correspondent: | Click to Email |
Due to recent shortages [1] and toxicity issues [2] of indium, Al-doped ZnO (AZO) have attracted much attention as alternatives to transparent conductive materials, such as Sn-doped In2O3 (ITO) films and indium zinc oxide (IZO). In general, AZO films deposited by magnetron sputtering showed large spatial distributions of electrical properties. Several investigations have suggested that such electrical property distributions should originate in the bombardments of the high-energy negative oxygen ions accelerated in cathode sheath region [3] or the oxidation enhancement by the activated oxygen sputtered from the oxide target and reaching at the growing film surface [4], both of which should take place at the locations in front of the erosion area of the magnetron cathode. In order to clarify the mechanisms of the degradation in the electrical properties, we investigated the dominant factors determining the electrical property distributions of AZO films deposited by dc magnetron sputtering using various sputtering gases, such as Ar, Kr or Xe. The spatial distributions clearly showed the dependence on a variety of the sputtering gases when the films were deposited on unheated glass substrate. In the cases of using Kr or Xe gases, the tendency to increase in the resistivity at the location in front of the erosion area was enhanced extremely compared with the case of using Ar. This could be attributed to the bombardment damages enhanced by the increasing sputtering voltages, because the plasma impedance increased by the smaller secondary electron emission coefficients for Kr or Xe impingements. We will also discuss on the oxidation effect of the activated oxygen or the bombardment effects by the high energy neutrals (Ar, Kr or Xe) on the electrical property distribution of AZO films. This work was partially supported by a High-Tech Research Center project for private universities with a matching fund subsidy from the Ministry of Education, Culture, Sports, Science, and Technology (MEXIT) of Japan.
[1] III-Vs Review 18 (8) (2005) p12.
[2] T. Homma et al., J. Occup . Health, 45 (2003) 137; T. Hamaguchi et al., Occup. Environ. Med. 65 (2008) 51.
[3] K. Tominaga et al., Jpn. J. Appl. Phys. 27, 1176 (1988).
[4] T. Minami et al., J. Vac. Sci. Technol. A 18, 1584 (2000)