AVS 46th International Symposium
    Electronic Materials and Processing Division Monday Sessions
       Session EM-MoM

Paper EM-MoM10
Photoluminescence and Heteroepitaxy of ZnO on Sapphire Substrate (0001) Grown by RF Magnetron Sputtering

Monday, October 25, 1999, 11:20 am, Room 608

Session: Nitride Epitaxy
Presenter: K.K. Kim, Kwangju Institute of Science and Technology, Korea
Authors: K.K. Kim, Kwangju Institute of Science and Technology, Korea
S.J. Park, Kwangju Institute of Science and Technology, Korea
J.-H. Song, Korea Institute of Science and Technology
H.-J. Jung, Korea Institute of Science and Technology
W.K. Choi, Korea Institute of Science and Technology
Correspondent: Click to Email
ZnO thin films were epitaxially grown on Al@sub 2@O@sub 3@ (0001) single crystalline substrate by RF magnetron sputtering with the variations of RF power P=60-120 W. Crystalline structure of the ZnO films were analyzed by 4-circle X-ray diffraction, backscattering (BS)/channeling, and transmission electron microscopy. At the substrate temperature 550@super o@C, the ZnO film deposited with power of 80W has narrowest full width half maximum(FWHM) of @theta@-rocking curve, 0.16@super o@, indicating an highly c-axis oriented columnar structure. XRD @theta@-rocking curve FWHM of the ZnO film deposited at 120 W and 600@super o@C was 0.13@super o@ and in-plane of ZnO grown on sapphire(0001) substrate was found to be indicated a 30@super o@ rotation of ZnO unit cell about sapphire(0001) substrate. In BS/channeling study, channeling yield minimum (@chi@ @sub m@) was changed with growing temperature and power, and was only 4-5% for the films deposited at 120 W, 600@super o@C. In PL measurement, only the sharp near band edge (NBE) emission were observed at room temperature for the films deposited at 80-120 W and 550@super o@C and 120 W, 600@super o@C. but deep-level emission were also detected in the films deposited at 60 W, 550@super o@C. The FWHM was decreased from 133 meV to 89 meV as RF power increased from 80 W to 120 W at 550@super o@C, and that of film deposited at 120 W and 600@super o@C showed 76 meV which is lower value than any other ever reported, which were somewhat opposite to that of XRD. From TEM analysis, grain size and defect were found to affect the PL properties. In this study, the PL property of undoped ZnO thin films is discussed in terms of the crystalline structure and the quality of grain.