A Study on the Characteristics of a MgZnO Schottky Diode by Rapid Thermal Annealing of Ag Metal

A Study on the Characteristics of a MgZnO Schottky Diode by Rapid Thermal Annealing of Ag Metal

Yun Been Na · Lili Yue · Hong Seung Kim

Department of Nano Semiconductor Engineering, Korea Maritime University, Busan 606-791, Korea

Jong Hoon Lee

Korea Research Institute of Standards and Science, Daejeon 305-340, Korea (Received 29 April 2015 : revised 21 June 2015 : accepted 1 July 2015)

If stable Schottky diode characteristics are to be obtained, a stable Schottky barrier must be formed. In this work, ZnO and Mg0.3Zn0.7O films were deposited by RF sputtering with ZnO and Mg0.3Zn0.7O targets, respectively. For the formation of the Schottky contact, Ag metal was used and was annealed by using a rapid thermal process in air at 300^◦C, sequentially. The Schottky diode characteristics of ZnO and Mg0.3Zn0.7O were compared to understand of the effect of Mg and rapid thermal annealing. While the ZnO film showed no Schottky diode property, the sample of Mg0.3Zn0.7O that had undergone rapid thermal annealing showed an Ion/Ioff ratio of > 10⁴, a threshold voltage of 1.10 V and a Schottky barrier of 1.10 eV.

PACS numbers: 61.66.Fn, 72.80.Ey, 81.40.Ef, 81.15.Cd

Keywords: MgZnO, Ag metal, Rapid thermal annealing, Schottky diode

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PACS numbers: 61.66.Fn, 72.80.Ey, 81.40.Ef, 81.15.Cd Keywords: MgZnO, Ag FK5Åq, /åL5Åq%P\ƒo, ®éàÔv sš¸×¼

∗E-mail: [email protected]

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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REFERENCES

[1] W. W. Wensa, A. Yamada, K. Takahashi, M.

Yoshino and M. Konagai, J. Appl. Phys. 70, 7119 (1991).

[2] D. C. Reynolda, D. C. Look and B. Jogai, Solid State Commun. 99, 873 (1996).

[3] D. C. Look, Water. Sci. Eng. B. 80, 383 (2001).

[4] H. S. Kang, J. W. Kim and S. Y. Lee, J. Appl. Phys.

95, 1246 (2004).

[5] H. Tanaka, S. Fujita and S. Fujita, Appl. Phys. Lett.

86, 192911 (2005).

[6] T. Takagi, H. Tanaka, S. Fujita and S. Fujita, Jpn.

J. Appl. Phys. 42, L401 (2003).

[7] Y. W. Heo, Y. W. Kwon, Y. Li, S. J. Pearton and D. P. Norton, Appl. Phys. Lett. 84, 3474 (2004).

[8] J. H. Kim, J. Y. Moon, H. S. Lee, C. H. Ahn and H.

K. Cho et al., J. Korean Phys. Soc. 53, 335 (2008).

[9] K. Ito and T. Nakazawa, Jpn. J. Appl. Phys. 22, L245 (1983).

[10] T. Minami, K. ohashi and S. Takata, Thin Solid Films 193/194, 721 (1990).

[11] M. Shimzu, Y. Matsueda, T. Shiosaki and A. Kawa- bata, J. Cryst. Growth 71. 209 (1985).

[12] P. Singer, Rapid Thermal Processing: A Progress Report (Semiconductor International, 1993), pp. 64- 69.

[13] R. P´eereza, N. Mestres, D. Tournier, P. Godignon and J.Mill´aan, Diam. Relat. Mater. 14, 1146 (2005).

[14] F. Roccaforte, F. La Via, A. Baeri, V. Raineri and L. Calcagno et al., J. Appl. Phys. 96, 4313 (2004).

[15] K. B. Sundaram and A. Khan, J. Vac. Sci. Technol.

A 15, 428 (1997).

[16] Y. Chen, H. J. Ko, S. K. Hong and T. Yao, Appl.

Phys. Lett. 76, 559 (2000).

[17] A. Ohotomo, M. Kawasaki, T. Koida, K. Masubuchi and H. Koinuma et al., Appl. Phys. Lett. 72, 2466 (1998).

[18] Y. W. Heo, L. C. Tien, D. P. Norton, S. J. Pearton and B. S. Kang et al., J. Jpn. Appl. Phys. 85, 15 (2004).

[19] J. H. Lee, C. H. Kim, A. R. Kim, H. S. Kim and N.

W. Jang, J. Jpn. Appl. Phys. 51, 09MF07-1 (2012).

[20] C. A. Mead, Phys. Lett. 18, 218 (1965).