Research Papers

Temperature-Dependent Electrical Characteristics of Ag Schottky Contacts to Differently Grown O-Polar Bulk ZnO

[+] Author and Article Information
Hogyoung Kim

Department of Optometry,
Seoul National University of Science
and Technology,
Seoul 139-743, Korea

Yunae Cho

Department of Physics,
Ewha Womans University,
Seoul 120-750, Korea

Dong-Wook Kim

Department of Physics,
Ewha Womans University,
Seoul 120-750, Korea;
Department of Chemistry and Nano Science,
Ewha Womans University,
Seoul 120-750, Korea
e-mail: dwkim@ewha.ac.kr

1Corresponding author.

Contributed by the Electronic and Photonic Packaging Division of ASME for publication in the Journal of Electronic Packaging. Manuscript received February 4, 2012; final manuscript received December 25, 2012; published online February 26, 2013. Assoc. Editor: Kyoung-sik Moon.

J. Electron. Packag 135(1), 011010 (Feb 26, 2013) (5 pages) Paper No: EP-12-1015; doi: 10.1115/1.4023404 History: Received February 04, 2012; Revised December 25, 2012

The temperature-dependent electrical properties of Ag Schottky contacts to differently grown O-polar bulk ZnO single crystals were comparatively investigated in the temperature range of 100–300 K. Schottky contact to hydrothermal ZnO produced the higher barrier heights (lower ideality factors) than that of pressurized melt-grown ZnO. The modified Richardson plots for two samples produced the larger Richardson constant compared to the theoretical value of 32 A cm−2 K−2 for n-type ZnO, indicating that the inhomogeneous barrier height with the thermionic emission (TE) model could not explain the current transport. The conductive accumulation layers on the ZnO surfaces might not be removed effectively for two samples, which degraded the rectifying characteristics. The different electron transport characteristics between hydrothermal and pressurized melt-grown ZnO could be explained by the different degree of Ag-O formation at the interface.

Copyright © 2013 by ASME
Topics: Temperature , Crystals
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Kim, Y.-J., Yoo, H., Lee, C.-H., Park, J. B., Baek, H., Kim, M., and Yi, G.-C., 2012, “Position- and Morphology-Controlled ZnO Nanostructures Grown on Graphene Layers,” Adv. Mater., 24, pp. 5565–5569. [CrossRef] [PubMed]
Um, H.-D., Moiz, S. A., Park, K.-T., Jung, J.-Y., Jee, S.-W., Ahn, C. H., Kim, D. C., Cho, H. K., Kim, D.-W., and Lee, J.-H., 2011, “Recent Highly Selective Spectral Response With Enhanced Responsivity of n-ZnO/p-Si Radial Heterojunction Nanowire Photodiodes,” Appl. Phys. Lett., 98, p. 033102. [CrossRef]
Chung, S. Y., Kim, S., Lee, J.-H., Kim, K., Kim, S.-W., Kang, C.-Y., Yoon, S.-J., and Kim, Y. S., 2012, “All-Solution-Processed Flexible Thin Film Piezoelectric Nanogenerator,” Adv. Mater., 24(45), pp. 6022–6027. [CrossRef] [PubMed]
Avrutin, V., Cantwell, G., Zhang, J., Song, J. J., Silversmith, D. J., and Morkoç, H., 2010, “Bulk ZnO: Current Status, Challenges, and Prospects,” Proc. IEEE, 98, pp. 1339–1350. [CrossRef]
Oshima, E., Ogino, H., Niikura, I., Maeda, K., Sato, M., Ito, M., and Fukuda, T., 2004, “Growth of the 2-in-Size Bulk ZnO Single Crystals by the Hydrothermal Method,” J. Cryst. Growth, 260, pp. 166–170. [CrossRef]
Nause, J., and Nemeth, B., 2005, “Pressurized Melt Growth of ZnO Boules,” Semicond. Sci. Technol., 20, pp. S45–S48. [CrossRef]
Lajn, A., Wenckstern, H., Zhang, Z., Czekalla, C., Biehne, G., Lenzner, J., Hochmuth, H., Lorenz, M., Grundmann, M., Wickert, S., Vogt, C., and Denecke, R., 2009, “Properties of Reactively Sputtered Ag, Au, Pd, and Pt Schottky Contacts on n-Type ZnO,” J. Vac. Sci. Technol. B, 27, pp. 1769–1773. [CrossRef]
Neville, R. C., and Mead, C. A., 1970, “Surface Barriers on Zinc Oxide,” J. Appl. Phys., 41, pp. 3795–3800. [CrossRef]
Allen, M. W., Durbin, S. M., and Metson, J. B., 2007, “Silver Oxide Schottky Contacts on n-Type ZnO,” Appl. Phys. Lett., 91, p. 053512. [CrossRef]
Endo, H., Sugibuchi, M., Takahashi, K., Goto, S., Sugimura, S., Hane, K., and Kashiwaba, Y., 2007, “Schottky Ultraviolet Photodiode Using a ZnO Hydrothermally Grown Single Crystal Substrate,” Appl. Phys. Lett., 90, p. 121906. [CrossRef]
Coppa, B. J., Fulton, C. C., Kiesel, S. M., Davis, R. F., Pandarinath, C., Burnette, J. E., Nemanich, R. J., and Smith, D. J., 2005, “Structural, Microstructural, and Electrical Properties of Gold Films and Schottky Contacts on Remote Plasma-Cleaned, n-type ZnO{0001} Surfaces,” J. Appl. Phys., 97, p. 103517. [CrossRef]
Kolkovsky, V., Scheffler, L., Hieckmann, E., Lavrov, E. V., and Weber, J., 2011, “Schottky Contacts on Differently Grown n-type ZnO Single Crystals,” Appl. Phys. Lett., 98, p. 082104. [CrossRef]
Kim, H., and Kim, D.-W., 2010, “Silver Schottky Contacts to a-Plane Bulk ZnO,” J. Appl. Phys., 108, p. 074514. [CrossRef]
Wenckstern, H., von Muller, S., Biehne, G., Hochmuth, H., Lorenz, M., and Grundmann, M., 2010, “Dielectric Passivation of ZnO-Based Schottky Diodes,” J. Electron. Mater., 39, pp. 559–562. [CrossRef]
Schmidt, O., Geis, A., Kiesel, P., Walle, C., Johnson, N., Bakin, A., Wagg, A., and Dohler, G., 2006, “Analysis of a Conducting Channel at the Native Zinc Oxide Surface,” Superlattices Microstruct., 39, pp. 8–16. [CrossRef]
Rhoderick, E., and Williams, R., Metal-Semiconductor Contacts, 2nd ed., Oxford University Press, New York.
Kampen, T. U., and Mönch, W., 1995, “Lead Contacts on Si(111):H-1×1 Surfaces,” Surf. Sci., 331–333, pp. 490–495. [CrossRef]
Werner, J. H., and Guttler, H. H., 1991, “Barrier Inhomogeneities at Schottky Contacts,” J. Appl. Phys., 69, pp. 1522–1533. [CrossRef]
Farag, A. A. M., Ashery, A., Terra, F. S., and Mahmoud, G. M., 2008, “Investigations of AlSb Thin Films Grown on Si by Liquid Phase Epitaxy,” J. Optoelectron. Adv. Matter., 10, pp. 2713–2718.
Turut, A., Saglam, M., Efeoglu, H., Yalcin, N., Yildirim, M., and Abay, B., 2005, “Interpreting the Nonideal Reverse Bias C-V Characteristics and Importance of the Dependence of Schottky Barrier Height on Applied Voltage,” Physica B, 205, pp. 41–50. [CrossRef]
Cheung, S. K., and Cheung, N. W., 1986, “Extraction of Schottky Diode Parameters From Forward Current-Voltage Characteristics,” Appl. Phys. Lett., 49, pp. 85–87. [CrossRef]
Chand, S., and Kumar, J., 1996, “On the Existence of a Distribution of Barrier Heights in Pd2Si/Si Schottky Diodes,” J. Appl. Phys., 80, pp. 288–294. [CrossRef]
Look, D., Coskun, C., Claflin, B., and Farlow, G., 2003, “Electrical and Optical Properties of Defects and Impurities in ZnO,” Physica B, 340–342, pp. 32–38. [CrossRef]
Osvald, J., and Horvath, J., Js., 2004, “Theoretical Study of the Temperature Dependence of Electrical Characteristics of Schottky Diodes With an Inverse Near-Surface Layer,” Appl. Surf. Sci., 234, pp. 349–354. [CrossRef]
Chand, S., and Kumar, J., 1996, “Evidence for the Double Distribution of Barrier Heights in Pd2Si/n-Si Schottky Diodes From I-V-T Measurements,” Semicond. Sci. Technol., 11, pp. 1203–1208. [CrossRef]
Forment, S., Van Meirhaeghe, R. L., De Vrieze, A., Strubbe, K., and Gomes, W. P., 2001, “A Comparative Study of Electrochemically Formed and Vacuum-Deposited n-GaAs/Au Schottky Barriers Using Ballistic Electron Emission Microscopy (BEEM),” Semicond. Sci. Technol., 16, pp. 975–981. [CrossRef]
Kumar, A. A., Janardhanam, V., Reddy, V. R., and Reddy, P. N., 2009, “Evaluation of Schottky Barrier Parameters of Pd/Pt Schottky Contacts on n-InP (100) in Wide Temperature Range,” Superlattices Microstruct., 45, pp. 22–32. [CrossRef]
Osvald, J., 2006, “Intersecting Behaviour of Nanoscale Schottky Diodes I–V Curves,” Solid State Commun., 138, pp. 39–42. [CrossRef]
Pakma, O., Serin, N., Serin, T., and Altındal, Ş., 2008, “The Influence of Series Resistance and Interface States on Intersecting Behavior of I–V Characteristics of Al/TiO2/p-Si (MIS) Structures at Low Temperatures,” Semicond. Sci. Technol., 23, p. 105014. [CrossRef]
Yu, L. S., Liu, Q. Z., Xing, Q. J., Qiao, D. J., Lau, S. S., and Redwing, J., 1998, “The Role of the Tunneling Component in the Current–Voltage Characteristics of Metal-GaN Schottky Diodes,” J. Appl. Phys., 84, pp. 2099–2104. [CrossRef]
Dong, Y., Fang, Z.-Q., Look, D. C., Doutt, D. R., Hetzer, M. J., and Brillson, L. J., 2009, “Polarity-Related Asymmetry at ZnO Surfaces and Metal Interfaces,” J. Vac. Sci. Technol. B, 27, pp. 1710–1716. [CrossRef]
Allen, M. W., Alkaisi, M. M., and Durbin, S. M., 2006, “Metal Schottky Diodes on Zn-Polar and O-Polar Bulk ZnO,” Appl. Phys. Lett., 89, p. 103520. [CrossRef]


Grahic Jump Location
Fig. 1

(a) and (b) room-temperature I–V characteristics measured in both air and vacuum condition

Grahic Jump Location
Fig. 2

Semilogarithmic I–V characteristics for the Ag Schottky contacts to (a) HT ZnO and (b) PM ZnO in the temperature range of 100–300 K. The measurements were done in vacuum.

Grahic Jump Location
Fig. 3

(a) Effective barrier height and (b) ideality factor as a function of temperature, estimated from the results in Fig. 2

Grahic Jump Location
Fig. 4

Series resistance as a function of temperature

Grahic Jump Location
Fig. 5

(a) and (b) Effective barrier height versus 1/2kBT plot and (c) and (d) modified Richardson plot of ln(I0/T2) – q2σ2/2kB2T2 versus 1/kBT with a double Gaussian distribution of barrier heights for both samples

Grahic Jump Location
Fig. 6

ln(I) versus V plots at small forward bias voltages for the different temperatures



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