Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-29T01:13:05.440Z Has data issue: false hasContentIssue false
  • English
  • Français

Transmission electron microscopy study of epitaxial InN thin films grown on c-plane sapphire

Published online by Cambridge University Press:  01 July 2006

C.J. Lu ,
X.F. Duan ,
Hai Lu  and
William J. Schaff
C.J. Lu*
Affiliation:
Department of Materials Science and Engineering, Hubei University, Wuhan, Hubei 430062, People's Republic of China
X.F. Duan
Affiliation:
Institute of Physics, Chinese Academy of Sciences, Beijing 100080, People's Republic of China
Hai Lu
Affiliation:
Department of Electrical and Computer Engineering, Cornell University, Ithaca, New York 14853
William J. Schaff
Affiliation:
Department of Electrical and Computer Engineering, Cornell University, Ithaca, New York 14853
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

High-quality epitaxial InN thin films grown on (0001) sapphire with GaN buffer were characterized using transmission electron microscopy. It was found that the GaN buffer layer exhibits the (0001) Ga polarity and the InN film has In-terminated polarity. At the InN/GaN interface, there exists a high density of misfit dislocation (MD) array. Perfect edge threading dislocations (TDs) with (1/3)〈1120〉 Burgers vectors are predominant defects that penetrate the GaN and InN layers. Pure screw and mixed TDs were also observed. Overall, the TD density decreases during film growth due to annihilation and fusion. The TD density in GaN is as high as ∼1.5 × 1011 cm−2, and it drops rapidly to ∼2.2 × 1010 cm−2 in InN films. Most half-loops in GaN are connected with MD segments at the InN/GaN interface to form loops, while some TD segments threaded the interface. Half-loops were also generated during the initial stages of InN growth.

Keywords

FilmMicrostructureTransmission electron microscopy (TEM)
Type
Articles
Information
Journal of Materials Research , Volume 21 , Issue 7 , July 2006 , pp. 1693 - 1699
Copyright
Copyright © Materials Research Society 2006

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

1.Yamaguchi, S., Kariya, M., Nitta, S., Takeuchi, T., Wetzel, C., Amano, H., Akasaki, I.: Structural properties of InN on GaN grown by metal organic vapor-phase epitaxy. J. Appl. Phys. 85, 7682 (1999).CrossRefGoogle Scholar
2.Lu, H., Schaff, W.J., Hwang, J., Wu, H., Koley, G., Eastman, L.F.: Effect of an AlN buffer layer on the epitaxial growth of InN by molecular epitaxy. Appl. Phys. Lett. 79, 1489 (2001).CrossRefGoogle Scholar
3.Higashiwaki, M., Matsui, T.: High-quality InN film grown on a low-temperature-grown GaN intermediate layer by plasma-assisted molecular-beam epitaxy. Jpn. J. Appl. Phys. 41, L540 (2002).CrossRefGoogle Scholar
4.Wu, J., Walukiewicz, W., Shan, W., Yu, K.M., III, J.W. Auger, Haller, E.E., Lu, H., Schaff, W.J.: Effects of the narrow band gap on the properties of InN. Phys. Rev. B 66, 201403 (2002).CrossRefGoogle Scholar
5.Davydov, V.Yu., Klochikhin, A.A., Seisyan, R.P., Emtsev, V.V., Ivanov, S.V., Bechstedt, F., Furthmuller, J., Harima, H., Mudryi, A.V., Aderhold, J., Semchinova, O., Graul, J.: Absorption and emission of hexagonal InN evidence of narrow fundamental band gap. Phys. Status Solidi (b) 229, R1 (2002).3.0.CO;2-O>CrossRefGoogle Scholar
6.Wu, J., Walukiewicz, W., Yu, K.M., III, J.W. Auger, Haller, E.E., Lu, H., Schaff, W.J., Saito, Y., Nanishi, Y.: Unusual properties of the fundamental band gap of InN. Appl. Phys. Lett. 80, 3967 (2002).CrossRefGoogle Scholar
7.Matsuoka, T., Okamoto, H., Nakao, M., Harima, H., Kurimoto, E.: Optical band gap energy of wurtzite InN. Appl. Phys. Lett. 81, 1246 (2002).CrossRefGoogle Scholar
8.Wu, J., Walukiewicz, W., Yu, K.M., III, J.W. Auger, Haller, E.E., Lu, H., Schaff, W.J.: Small band gap bowing in In1−xGaxN alloys. Appl. Phys. Lett. 80, 4741 (2002).CrossRefGoogle Scholar
9.Hino, T., Tomiya, S., Miyajima, T., Yanashima, K., Hashimoto, S., Ikeda, M.: Characterization of threading dislocations in GaN epitaxial layers. Appl. Phys. Lett. 76, 3421 (2000).CrossRefGoogle Scholar
10.Nakamura, S., Senoh, M., Nagahama, S., Iwasa, N., Yamada, T., Matsushita, T., Kiyoku, H., Sugimoto, Y., Kozaki, T., Umemoto, H., Sano, M., Chocho, K.: InGaN/GaN/AlGaN-based laser diodes with modulation-doped strained-layer superlattices grown on an epitaxially laterally overgrown GaN substrate. Appl. Phys. Lett. 72, 211 (1998).CrossRefGoogle Scholar
11.Kozodoy, P., Ibbetson, J.P., Marchand, H., Fini, P.T., Keller, S., Speck, J.S., DenBaars, S.P., Mishra, U.K.: Electrical characterization of GaN p-n junctions with and without threading dislocations. Appl. Phys. Lett. 73, 975 (1998).CrossRefGoogle Scholar
12.Hellman, E.S.: The polarity of GaN: A critical review. MRS Internet J. Nitride Semicond. Res. 3, 11 (1998).CrossRefGoogle Scholar
13.Seelmann-Eggebert, M., Weher, J.L., Obloh, H., Zimmermann, H., Rar, A., Porowski, S.: Polarity of (00.1) GaN epilayers grown on a (00.1) sapphire. Appl. Phys. Lett. 71, 2635 (1997).CrossRefGoogle Scholar
14.Daudin, B., Rouvière, J.L., Arlery, M.: Polarity determination of GaN films by ion channeling and convergent beam electron diffraction. Appl. Phys. Lett. 69, 2480 (1996).CrossRefGoogle Scholar
15.Ponce, F.A., Bour, D.P.: Determination of lattice polarity for growth of GaN bulk single crystals and epitaxial layers. Appl. Phys. Lett. 69, 337 (1996).CrossRefGoogle Scholar
16.Qian, W., Skowronski, M., De Graef, M., Doverspike, K., Rowland, L.B., Gaskill, D.K.: Microstructural characterization of α–GaN films grown on sapphire by organometallic vapor phase epitaxy. Appl. Phys. Lett. 66, 1252 (1995).CrossRefGoogle Scholar
17.Ning, X.J., Chien, F.R., Pirouz, P., Yang, J.W., Khan, M. Asif: Growth defects in GaN films on sapphire: The probable origin of threading dislocations. J. Mater. Res. 11, 580 (1996).CrossRefGoogle Scholar
18.Narayanan, V., Lorenz, K., Kim, W., Mahajan, S.: Origins of threading dislocations in GaN epitaxial layers grown on sapphire by metalorganic chemical vapor deposition. Appl. Phys. Lett. 78, 1544 (2001).CrossRefGoogle Scholar
19.Lu, C.J., Bendersky, L.A., Lu, H., Schaff, W.J.: Threading dislocations in epitaxial InN thin films grown on 0001 sapphire with a GaN buffer layer. Appl. Phys. Lett. 83, 2817 (2003).CrossRefGoogle Scholar
20.Araki, T., Ueta, S., Mizuo, K., Yamaguchi, T., Saito, Y., Nanishi, Y.: TEM characterization of InN films grown by RF-MBE. Phys. Status Solidi (c) 0(7), 2798 (2003).CrossRefGoogle Scholar
21.Jasinski, J., Liliental-Weber, Z., Lu, H., Schaff, W.J.: V-shaped inversion domains in InN grown on c-plane sapphire. Appl. Phys. Lett. 85, 233 (2004).CrossRefGoogle Scholar
22.Lu, H., Schaff, W.J., Hwang, J., Wu, H., Yeo, W., Pharkya, A., Eastman, L.F.: Improvement on epitaxial grown of InN by migration enhanced epitaxy. Appl. Phys. Lett. 77, 2548 (2000).CrossRefGoogle Scholar
23.Ruterana, P., Nouet, G.: Atomic structure of extended defects in wurtzite GaN epitaxial layers. Phys. Status Solidi 227, 177 (2001).3.0.CO;2-7>CrossRefGoogle Scholar
24.Onozu, T., Gunji, I., Miura, R., Ammal, S.S.C., Kubo, M., Teraishi, K., Miyamoto, A., Iyechika, Y., Maeda, T.: Computational studies on GaN surface polarity and InN/GaN heterostructures by density-functional theory and molecular dynamics. Jpn. J. Appl. Phys. Part 1 38, 2544 (1999).Google Scholar