Heteroepitaxial growth of non-polar ZnO films on single crystal NdGaO sub(3) (001) substrates by MOCVD

• Published in: Physica status solidi. C Vol. 11; no. 7-8; pp. 1361 - 1364
• Main Authors: Kashiwaba, Yasuhiro, Yokoyama, Tai, Sakuma, Mio, Abe, Takami, Nakagawa, Akira, Niikura, Ikuo, Kashiwaba, Yasube, Daibo, Masahiro, Osada, Hiroshi
• Format: Journal Article
• Language: English
• Published: 01.07.2014
• Subjects: Epitaxial growth; Excitation spectra; Planes; Single crystals; Solid state physics; Spectral emissivity; X-ray diffraction; Zinc oxide
• DOI: 10.1002/pssc.201300573
• ISSN: 1862-6351

High-quality non-polar ZnO (11 $ \bar 2 $ 0) films were epitaxially grown on single crystal NdGaO sub(3) (NGO) (001) substrates. The non-polar ZnO (11 $ \bar 2 $ 0) films were grown by metal organic chemical vapour deposition using Zn(C sub(5)H sub(7)O sub(2)) sub(2) and O sub(2) gas as starting materials. X-ray diffraction (XRD) peaks of ZnO (11 $ \bar 2 $ 0) plane were observed in XRD patterns of 2[thetas]- omega scans in all films. Rotation domains were not found in XRD phi scan patterns of ZnO (11 $ \bar 2 $ 0) films grown at a substrate temperature of 650 degree C or less. XRD peaks of NGO (021) and ZnO (11 $ \bar 2 $ 2) planes were observed at the same angle phi in the XRD phi scan patterns. The epitaxial relationship was ZnO (11 $ \bar 2 $ 0)// NGO (001) and ZnO [0001] // NGO [010]. Lattice mismatch values along the ZnO [0001] direction and along the ZnO (1 $ \bar 1 $ 00) direction were 5.36% and -3.70%, respectively. Growth rate was drastically decreased at the substrate temperature over 650 degree C. Striped patterns along the ZnO [0001] direction were observed in atomic force microscopy images of ZnO (11 $ \bar 2 $ 0) films grown at substrate temperatures of 600 and 650 degree C. Emissions due to donor-bound excitions were observed in photoluminescence spectra of ZnO (11 $ \bar 2 $ 0) films measured at 10 K. It is thought that NGO (001) substrates are useful for growth of high-quality non-polar ZnO (11 $ \bar 2 $ 0) films. ( copyright 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)