Microstructures of ZnO films deposited on (0001) and r-cut α-Al2O3 using metal organic chemical vapor deposition
Zinc oxide films were deposited on (0001) and r-cut α-Al2O3 under identical conditions using metal organic chemical vapor deposition. Microstructures of the ZnO films were studied in detail using conventional and high-resolution transmission electron microscopy (HRTEM), electron diffraction, and HRTEM image simulations. The films deposited on these two substrates show distinctive structural differences. The film grown on r-cut α-Al2O3 shows a high quality single crystal with an orientation relationship of α-Al2O3[-101-1]//ZnO[0001] and α-Al2O3(10-1-2)//ZnO(2-1-10). The interface between the film and the substrate was abrupt and decorated with high density of misfit dislocations. Film grown on α-Al2O3 (0001) shows several orientation domains. Typically, one domain correspond to the classic growth model such that α-Al2O3 (0001)//ZnO(0001) and α-Al2O3 [11-20]//ZnO[10-10]. Another domain corresponds to the growth mode such that α-Al2O3 [11-20]//ZnO[10-10] but the (0001) plane of ZnO is tilted relative to the (0001) plane of α-Al2O3 such that ZnO(0001) is almost parallel to the α-Al2O3 (-1104) plane. This orientation reduces the extent of lattice mismatch as compared with the classic growth mode. The interface between ZnO and α-Al2O3 is abrupt and possesses periodic dislocations.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 946658
- Report Number(s):
- PNNL-SA-57308; THSFAP; 19595; KP1704020; TRN: US200903%%545
- Journal Information:
- Thin Solid Films, 516(23):8337-8342, Vol. 516, Issue 23; ISSN 0040-6090
- Country of Publication:
- United States
- Language:
- English
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