Hostname: page-component-7479d7b7d-fwgfc Total loading time: 0 Render date: 2024-07-09T00:37:16.688Z Has data issue: false hasContentIssue false

Microstructure and secondary phase segregation correlation in epitaxial/oriented ZnO films with unfavorable Cr dopant

Published online by Cambridge University Press:  31 January 2011

M.H. Engelhard
Affiliation:
Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352
Get access

Abstract

Low solubility dopant-host systems are well suited to study secondary phase segregation-microstructure dependence. We discuss the effect of microstructure on secondary phase segregation in epitaxial/oriented ZnO thin films with Cr as an unfavorable dopant (Cr:ZnO). Since differences in thin film microstructure are a function of the substrate and its orientation, simultaneous chemical vapor depositions were carried out on single crystals of Si (100), c-axis oriented Al2O3 (c-ALO), and r-axis oriented Al2O3 (r-ALO) resulting in epitaxial film growth on r-ALO and c-axis oriented film growth on Si and c-ALO, with a difference in vertical grain boundary density. To enhance the analysis sensitivity to the microstructure difference, the thickness of Cr:ZnO films was maintained at ∼50 nm. High-resolution transmission electron microscopy (HRTEM) analysis indicates uniform stress distribution in Cr:ZnO grown on r-ALO. Surface sensitive x-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectroscopy (TOF-SIMS) techniques were utilized for analysis of the data. We observe that a higher grain boundary density and the presence of an amorphous layer at the interface for films grown on Si(100) single crystal led to interfacial Cr-based secondary phase segregation as opposed to lower grain boundary density and epitaxial films grown on c-ALO and r-ALO single crystals, respectively. We also discuss the effects of trace carbon solubility on the film microstructure/secondary phase segregation relationship.

Type
Articles
Copyright
Copyright © Materials Research Society 2009

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.Triboulet, R., Perrière, J.: Epitaxial growth of ZnO films. Prog. Cryst. Growth Charact. Mater. 47, 65(2003)CrossRefGoogle Scholar
2.Jin, Z., Murakami, M., Fukumura, T., Matsumoto, Y., Ohtomo, A., Kawasaki, M., Koinuma, H.: Combinatorial laser MBE synthesis of 3D ion doped epitaxial ZnO thin films. J. Cryst. Growth 214–215, 55(2000)Google Scholar
3.de la, M., Olvera, L., Maldonado, A., Matsumoto, Y., Asomoza, R., Melendez-Lira, M., Acosta, D.R.: Chromium doped ZnO thin films deposited by chemical spray: Chromium effect. J. Vac. Sci. Technol., A 19, 2097 (2001)CrossRefGoogle Scholar
4.Saraf, L.V., Engelhard, M.H., Nachimuthu, P., Shutthanandan, V., Wang, C.M., Heald, S.M., McCready, D.E., Lea, A.S., Baer, D.R., Chambers, S.A.: Nucleation and growth of MOCVD grown (Cr, Zn)O films: Uniform doping vs secondary phase formation. J. Electrochem. Soc. 154, D134 (2007)CrossRefGoogle Scholar
5.Smith, D.L.: Thin Film Deposition; Principles and Practice(McGraw Hill New York 1995)221306Google Scholar
6.Saraf, L.V., Engelhard, M.H., Wang, C.M., Lea, A.S., McCready, D.E., Shutthanandan, V., Baer, D.R., Chambers, S.A.: Metalorganic chemical vapor deposition of carbon-free ZnO using the bis(2,2,6,6-tetramethyl-3,5-heptanedionato)zinc precursor. J. Mater. Res. 22, 1230 (2007)CrossRefGoogle Scholar
7.Achiwawanich, S., James, B.D., Liesegang, J.: XPS and ToF-SIMS analysis of natural rubies and sapphires heated in an inert (N2) atmosphere. Appl. Surf. Sci. 253, 6883 (2007)CrossRefGoogle Scholar
8.Lieberman, A.G.: Problems in using surface analysis techniques for the depth profiling of microelectronic materials, in National Bureau of Standards, International Meeting on Electron Devices Vol. 21, (1975)126Google Scholar
9.Lazzeri, P., Clauser, G., Lacob, E., Lui, A., Tonidandel, G., Anderle, M.: ToF-SIMS and XPS characterization of urban aerosols for pollution studies. Appl. Surf. Sci. 203–204, 767 (2003)CrossRefGoogle Scholar
10.Saraf, L.V., McCready, D.E., Shutthanandan, V., Wang, C.M., Engelhard, M.H., Thevuthasan, S.: Correlation among channeling, morphological, and microstructural properties in epitaxial CeO2 films. Electrochem. Solid-State Lett. 9, J17 (2006)CrossRefGoogle Scholar
11.Kaiser, S., Preis, H., Gebhardt, W., Ambacher, O., Angerer, H., Stutzmann, M., Rosenauer, A., Gerthsen, D.: Quantitative transmission electron microscopy investigation of the relaxation by misfit dislocations confined at the interface of GaN/Al2O3(0001). Jpn. J. Appl. Phys. 37, 84(1998)CrossRefGoogle Scholar
12.Marinkovic, Z.V., Mancic, L., Vulic, P., Milosevic, O.: Microstructural characterization of mechanically activated ZnO–Cr2O3 system. J. Eur. Ceram. Soc. 25, 2081 (2005)CrossRefGoogle Scholar
13.Gorla, C.R., Emanetoglu, N.W., Liang, S., Mayo, W.E., Lu, Y., Wraback, M., Shen, H.: Structural, optical, and surface acoustic wave properties of epitaxial ZnO films grown on (012) sapphire by metalorganic chemical vapor deposition. J. Appl. Phys. 85, 2595 (1999)CrossRefGoogle Scholar
14.Gorla, C.R., Mayo, W.E., Liang, S., Lu, Y.: Structure and interface-controlled growth kinetics of ZnAl2O4 formed at the (110) ZnO/(012) Al2O3 interface. J. Appl. Phys. 87, 3736 (2000)CrossRefGoogle Scholar
15.Lim, S.: Structural defects in an epitaxial ZnO/(012) r-plane sapphire studied by high-resolution electron microscopy and computer simulation. J. Vac. Sci. Technol., A 24, 264 (2006)CrossRefGoogle Scholar
16.Narayan, J., Larson, B.C.: Domain epitaxy: A unified paradigm for thin film growth. J. Appl. Phys. 93, 278 (2003)CrossRefGoogle Scholar
17.Knauth, P., Tuller, H.L.: Solute segregation, electrical properties and defect thermodynamics of nanocrystalline TiO2 and CeO2. Solid State Ionics 136–137, 1215 (2000)CrossRefGoogle Scholar
18.Saraf, L.V., Shutthanandan, V., Zhang, Y., Thevuthasan, S., Wang, C.M., El-Azab, A., Baer, D.R.: Distinguishibility of oxygen desorption from the surface region with mobility dominant effects in nanocrystalline ceria films. J. Appl. Phys. 96, 5756 (2004)CrossRefGoogle Scholar
19.Saraf, L.V., Wang, C.M., Engelhard, M.H., Baer, D.R.: Temperature-induced phase separation in chromium films. Appl. Phys. Lett. 82, 2230 (2003)CrossRefGoogle Scholar
20.Komatsu, M., Ohashi, N., Sakaguchi, I., Hishita, H., Haneda, H.: Ga, N solubility limit in co-implanted ZnO measured by secondary ion mass spectrometry. Appl. Surf. Sci. 189, 349(2002)CrossRefGoogle Scholar
21.Ignavota, V., Karpuzov, D., Chakarov, I., Katardjiev, I.: Computer simulations of surface analysis using ion beams. Prog. Surf. Sci. 81 247, (2006)Google Scholar
22.Kim, T.H., Nam, S.H., Park, H.S., Song, J.K., Park, S.M.: Effects of transverse magnetic field on a laser-produced Zn plasma plume and ZnO films grown by pulsed laser deposition. Appl. Surf. Sci. 253, 8054 (2007)CrossRefGoogle Scholar
23.Bartschat, K.: Electron scattering from laser-excited chromium atoms. J. Phys. B: At. Mol. Opt. Phys. 28, 879 (1995)CrossRefGoogle Scholar
25.Van Craen, M.J., Adams, F.C.: Secondary ion emission of metal oxide species and their dependence on the fragment valence. Surf. Interface Anal. 5, 239 (1983)CrossRefGoogle Scholar
26.Kikuma, J., Imai, H.: Yield enhancement effect of low-energy O2+ ion bombardment in Ga focused ion beam SIMS. Surf. Interface. Anal. 31, 901 (2001)CrossRefGoogle Scholar
27.Li, X., Asher, S.E., Limpijumnong, S., Keyes, B.M., Perkins, C.L., Barnes, T.M., Moutinho, H.R., Luther, J.M., Zhang, S.B., Wei, S., Coutts, T.J.: Impurity effects in ZnO and nitrogen-doped ZnO thin films fabricated by MOCVD. J. Cryst. Growth 287, 94 (2006)CrossRefGoogle Scholar
28.Nickel, N.H., Friedrich, F., Rommeluère, J.F., Galtier, P.: Vibrational spectroscopy of undoped and nitrogen-doped ZnO grown by metalorganic chemical vapor deposition. Appl. Phys. Lett. 87, 211905 (2005)CrossRefGoogle Scholar