Epitaxial growth of ( $$11\bar 20$$ ) ZnO on ( $$01\bar 12$$ ) Al2O3 by metalorganic chemical vapor deposition2) Al2O3 by metalorganic chemical vapor deposition

Autor: C. R. Gorla, S. Liang, William E. Mayo, Yicheng Lu, Nuri W. Emanetoglu, Y. Liu
Rok vydání: 1998
Předmět:
Zdroj: Journal of Electronic Materials. 27:L72-L76
ISSN: 1543-186X
0361-5235
DOI: 10.1007/s11664-998-0083-6
Popis: There has been increased interest in high quality ZnO films for use in a diverse range of applications such as in high frequency surface acoustic wave filters, buffer layers for GaN growth, transparent and conductive electrodes, and solid state lasers. In the present paper, ZnO films were epitaxially grown on R-plane sapphire substrates by metalorganic chemical vapor deposition at temperatures in the range 350–450°C. X-ray diffraction and electron microscopy results indicate that the ZnO films are epitaxially grown on (\(01\bar 12\)) Al2O3 surface with the (\(11\bar 20\)) plane parallel to the surface. Cross-sectional high resolution-transmission electron microscopy imaging of the as-grown film shows that the interface is semi-coherent and atomically sharp, with misfit dislocations relieving the misfit strain between ZnO and sapphire. In order to check the thermal stability of the as-grown ZnO films, annealing in an O2+N2 ambience at 850°C for 30 min was performed. The annealed films showed improved crystallinity. At the same time, limited reaction between ZnO and sapphire occurred, resulting in the formation of a 15–20 nm thick spinel layer at the interface.
Databáze: OpenAIRE
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