Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-22T21:28:39.588Z Has data issue: false hasContentIssue false

Change in polarity of zinc oxide films grown on sapphire substrates without insertion of any buffer layer

Published online by Cambridge University Press:  31 January 2011

Yutaka Adachi*
Affiliation:
National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
Naoki Ohashi
Affiliation:
National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
Tsuyoshi Ohnishi
Affiliation:
National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
Takeshi Ohgaki
Affiliation:
National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
Isao Sakaguchi
Affiliation:
National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
Hajime Haneda
Affiliation:
National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
Mikk Lippmaa
Affiliation:
Institute of Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

We have investigated the polarity of zinc oxide (ZnO) and Al-doped ZnO films grown on (11¯20) and (0001) sapphire substrates, using coaxial impact collision ion scattering spectroscopy. The films grown by pulsed laser deposition with a nominally undoped ZnO ceramic target had a (000¯1) surface, whereas the films prepared with a 1 mol% Al-doped ZnO ceramic target had a (0001) surface. The usage of Al-doped and undoped targets caused no difference in the in-plane lattice orientation. Electron microscope observations revealed that polarity change due to doping occurred without the formation of any interfacial phase between ZnO and sapphire.

Type
Articles
Copyright
Copyright © Materials Research Society 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Ohta, H., Kawamura, K., Orita, M., Hirano, M., Sarukura, H., Hosono, H.: Current injection emission from a transparent p-n junction composed of p-SrCu2O2/n-ZnO. Appl. Phys. Lett. 77, 475 2000CrossRefGoogle Scholar
2Wander, A., Schedin, F., Steadman, P., Norris, A., McGrath, R., Turner, T.S., Thornton, G., Harrison, N.M.: Stability of polar oxide surfaces. Phys. Rev. Lett. 86, 3811 2001CrossRefGoogle ScholarPubMed
3Ohashi, N., Takahashi, K., Hishita, S., Sakaguchi, I., Funakubo, H., Haneda, H.: Fabrication of ZnO microstructures by anisotropic wet-chemical etching. J. Electrochem. Soc. 154, D82 2007CrossRefGoogle Scholar
4Ohashi, N., Kataoka, K., Ohgaki, T., Sakaguchi, I., Haneda, H., Kitamura, K., Fujimoto, M.: Role of crystalline polarity in interfacial properties of zinc oxide varistors. Jpn. J. Appl. Phys. 46, L1042 2007CrossRefGoogle Scholar
5Tsukazaki, A., Ohtomo, A., Kita, T., Ohno, Y., Ohno, H., Kawasaki, M.: Quantum Hall effect in polar oxide heterostructures. Science 315, 1388 2007CrossRefGoogle ScholarPubMed
6Maki, H., Sakaguchi, I., Ohashi, N., Sekiguchi, S., Haneda, H., Tanaka, J., Ichinose, N.: Nitrogen ion behavior on polar surface of ZnO single crystals. Jpn. J. Appl. Phys. 42, 75 2003Google Scholar
7Sakagami, N., Yamashita, M., Sekiguchi, T., Miyashita, S., Obara, K., Shishido, T.: Variation of electrical properties on growth sectors of ZnO single crystals. J. Cryst. Growth 229, 98 2001CrossRefGoogle Scholar
8Ohnishi, T., Ohtomo, A., Kawasaki, M., Takahashi, K., Yoshimoto, M., Koinuma, H.: Determination of surface polarity of c-axis oriented ZnO films by coaxial impact-collision ion scattering spectroscopy. Appl. Phys. Lett. 72, 824 1998CrossRefGoogle Scholar
9Kato, H., Miyamoto, K., Sano, M., Yao, T.: Polarity control of ZnO on sapphire by varying the MgO buffer layer thickness. Appl. Phys. Lett. 84, 4562 2004Google Scholar
10Wang, Y., Du, X.L., Mei, Z.X., Zeng, Z.Q., Ying, M.J., Yuan, H.T., Jia, J.F., Xue, Q.K., Zhang, Z.: Cubic nitridation layers on sapphire substrate and their role in polarity selection of ZnO films. Appl. Phys. Lett. 87, 051901 2005CrossRefGoogle Scholar
11Hong, S-K., Haneda, T., Chen, Y., Ko, H-J., Yao, T., Imai, D., Araki, K., Shinohara, M.: Control of polarity of heteroepitaxial ZnO films by interface engineering. Appl. Surf. Sci. 190, 491 2002CrossRefGoogle Scholar
12Park, J.S., Hong, S.K., Minegishi, T., Park, S.H., Im, I.H., Hanada, T., Cho, M.W., Yao, T., Lee, J.W., Lee, J.Y.: Polarity control of ZnO films on (0001) Al2O3 by Cr-compound intermediate layers. Appl. Phys. Lett. 90, 201907 2007CrossRefGoogle Scholar
13Okubo, I., Ohtomo, A., Ohnishi, T., Mastumoto, Y., Koinuma, H., Kawasaki, M.: In-plane and polar orientations of ZnO thin films grown on atomically flat sapphire. Surf. Sci. Lett. 443, 1043 1999CrossRefGoogle Scholar
14Nakahara, K., Tanabe, T., Takasu, H., Fons, P., Iwata, K., Yamada, A., Matsubara, K., Hunger, R., Niki, S.: Growth of undoped ZnO films with improved electrical properties by radical source molecular beam epitaxy. Jpn. J. Appl. Phys. 40, 250 2001CrossRefGoogle Scholar
15Ohgaki, T., Kawamura, Y., Kuroda, T., Ohashi, N., Adachi, Y., Tsurumi, T., Minami, F., Haneda, H.: Optical properties of heavily aluminum-doped zinc oxide thin films prepared by molecular beam epitaxy. Key Eng. Mater. 248, 91 2003Google Scholar
16Wang, Y-G., Ohashi, N., Wada, Y., Sakaguchi, I., Ohgaki, T., Haneda, H.: Lowering of stimulated emission threshold of zinc oxide by doping with thermally diffused aluminum supplied from sapphire substrate. J. Appl. Phys. 100, 023524 2006Google Scholar
17Ryoken, H., Ohashi, N., Sakaguchi, I., Adachi, Y., Hishita, S., Haneda, H.: Structures and properties of (Zn,Mg)O films studied from the aspect of phase equilibria. J. Cryst. Growth 287, 134 2006CrossRefGoogle Scholar