Browse > Article

A Study on the Effect of O$_2$ annealing on Structural, Optical, and Electrical Characteristics of Undoped ZnO Thin Films Deposited by Magnetron Sputtering  

Yun, Eui-Jung (Hoseo University)
Park, Hyeong-Sik (Sungkyunkwan University)
Publication Information
Abstract
In this paper, the effects of annealing conditions on the structural ((002) intensity, FWHM, d-spacing, grain size, (002) peak position), optical (UV peak, UV peak position) and electrical properties (carrier concentrations, resistivity, mobility) of ZnO films were investigated. ZnO films were deposited onto SiO$_2$/si substrates by RF magnetron sputtering from a ZnO target. The substrate was not heated during deposition. ZnO films were annealed in temperature ranges of $500\sim650^{\circ}C$ in the O$_2$ flow for 5$\sim$20 min. The film average thicknesses were in the range of 291 nm. The surface morphologies and structures of the samples were characterize by SEM and XRD, respectively. The optical properties were evaluated by photoluminescence (PL) measurement at room temperature (RT) using a He-Cd 325 nm laser. As the annealing temperature and time vary, the following relations were also observed: (1) proportional relationships among UV intensity (002) intensity, and grain size exist, (2) UV intensity is inversely proportional to FWHM, (3) there is no special relationship between UV intensity and electron carrier concentrations, (4) d-spacing is inversely proportional to (002) peak position, (5) UV peak position in the range of 3.20$\sim$3.24 eV means that ZnO films have a n-type conductivity which was consistent with that obtained from the electrical property, (6) the optimal conditions for the best optical and structural characteristics were found to be oxygen fraction, (O$_2$/(O$_2$+Ar)) of 0.2, RF power of 240W, substrate temperature of RT, annealing condition of 600$^{\circ}C$ for 20 min, and sputtering pressure of 20 mTorr.
Keywords
undoped ZnO films; structural; optical; and electrical properties; RF magnetron sputtering; O$_2$ annealing effect;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 S. J. Pearton, D. P. Norton, K lp, Y. W. Heo, and T. Steiner, Prog in Materials Science. 50, 293(2005)
2 F. Oba, S. R. Nishitani, S. Isotani, and H. Adachi, J. Appl. Phys. 90, 824 (2001)   DOI   ScienceOn
3 D. J. Chadi, Phys. Rev. B. 59, 15181 (1999)   DOI
4 G. Xiong, J. Wilkinson, B. Mischuck, S. Tuzemen, K. B. Ucer and, R. T. Williams, Appl. Phys. Lett. 80, 1195 (2002)   DOI   ScienceOn
5 Anderson Janotti and Chris G. Van de WaIle, Appl. Phys. Lett. 87, 122102 (2005)   DOI   ScienceOn
6 E.-j. Yun, H-S. Park, K H Lee and H G. Nam, 'Characterization of Undoped ZnO Films Post-Annealed by Using Helium Gas' J. Korean Phys. Soc. 54, 825 (2009)   DOI   ScienceOn
7 T. M. Barnes, K. Olson, and C. A. Wolden, Appl. Phys. Lett. 86, 112112 (2005)   DOI   ScienceOn
8 Y. Chen, F. Jiang, L. Wang, C. Mo, Y. Pu, W. Fang, J. Crys. Grow. 268, 71 (2004)   DOI   ScienceOn
9 Y. R. Ryu and T. S. Lee, J. H. Leem, Appl. Phys, Lett. 83, 4032 (2003)   DOI   ScienceOn
10 S. Limpijumnong, S. B. Zhang, S. H. Wei, and C. H. Park, Phys. Rev. Lett. 92, 155504 (2004)   DOI   ScienceOn
11 H. S. Kang, G. H. Kim, S. H. Lim, and H. W. Chang, J. H. Kim, S. Y. Lee, Thin Solid Films (2007), doi:l0.l016/j.tsf.2oo7.08.084   DOI
12 B. D. Cullity, Elements of X-ray diffraction (Addison-Wesley, Massachusetts, 1978), p.102
13 E.-j. Yun, H-S. Park, K-H Cha, K H Lee, N.-I. Cho and H G. Nam, "Effect of Hydrogen Peroxide on the Stability of Undoped p-type ZnO Prepared by Magnetron Sputtering" J. Korean Phys. Soc. 52, 606 (2008)   DOI   ScienceOn
14 S. B. Zhang, S. H. Wei, and Alex Zunger, Phys Rev B. 63, 075205 (2001)   DOI   ScienceOn