Analysis on the Field Effect Mobility Variation of Tin Oxide Thin Films with Oxygen Partial Pressure

산소 분압에 따른 산화주석 박막의 전계효과 이동도 변화 분석

  • Ma, Tae Young (Department of Electrical Engineering and ERI, Gyeongsang national University)
  • 마대영 (경상대학교 전기공학과 및 공학연구원)
  • Received : 2014.03.25
  • Accepted : 2014.05.21
  • Published : 2014.06.01


Bottom-gate tin oxide ($SnO_2$) thin film transistors (TFTs) were fabricated on $N^+$ Si wafers used as gate electrodes. 60-nm-thick $SnO_2$ thin films acting as active layers were sputtered on $SiO_2/Al_2O_3$ films. The $SiO_2/Al_2O_3$ films deposited on the Si wafers were employed for gate dielectrics. In order to increase the resistivity of the $SnO_2$ thin films, oxygen mixed with argon was introduced into the chamber during the sputtering. The mobility of $SnO_2$ TFTs was measured as a function of the flow ratio of oxygen to argon ($O_2/Ar$). The mobility variation with $O_2/Ar$ was analyzed through studies on crystallinity, oxygen binding state, optical properties. X-ray diffraction (XRD) and XPS (X-ray photoelectron spectroscopy) were carried out to observe the crystallinity and oxygen binding state of $SnO_2$ films. The mobility decreased with increasing $O_2/Ar$. It was found that the decrease of the mobility is mainly due to the decrease in the polarizability of $SnO_2$ films.


  1. A. Kumar, P. Zhang, A. Vincent, R. McCormack, R. Kalyanaraman, H. J. Cho, and S. Seal, Sensors and Actuators B: Chemical, 155, 884 (2011).
  2. N. Yamazoe, K. Suematsu, and K. Shimanoe, Sensors and Actuators B: Chemical, 176, 443 (2013).
  3. S. K. Lee, D. I. Chang, and S. W. Kim, J. of Hazard. Mater., 268, 110 (2014).
  4. C. N. Cha, M. H. Choi, and T. Y. Ma, Mater. Sci. in Semicon. Proc., 15, 240 (2012).
  5. T. Y. Ma, J. KIEEME, 25, 304 (2011).
  6. Y. Huang, Z. Ji, and C. Chen, Appl. Surf. Sci., 253, 4819 (2007).
  7. T. Toyama, Y. Seo, T. Konishi, H. Okamoto, R. Morimoto, Y. Nishikawa, and Y. Tsutsumi, Thin Solid Films, 555, 148 (2014).
  8. D. K. Schroder, Semiconductor Material and Device Characterization (Wiley-Interscience Publication, 1990) p. 285.
  9. A. L. Patterson, Phys. Rev., 56, 978 (1939).
  10. E. Ziegler, A. Heinrich, H. Oppermann, and G. Stover, Phys. Status Solidi A, 66, 635 (1981).
  11. E. Marquez, J. M. Gonzalez-Leal, R. Jimenez-Garay, S. R. Lukic, and D. M. Petrovic, J. Phys. D: Appl. Phys., 30, 690 (1997).
  12. L. Y. Liang, Z. M. Liu, H. T. Caoz, Z. Yu, Y. Y. Shi, A. H. Chen, H. Z. Zhang, Y. Q. Fang, and X. L. Sun, J. Electrochem. Soc., 157, H598 (2010).
  13. R. Swanepoel, J. Phys. E: Sci. Instrum. 16, 1214 (1983).
  14. L. Jie and X. Chao, J. of Non-Cryst. Solids, 119, 37 (1990).