Polarity dependence and characterization of high-quality homoepitaxial ZnO layers grown on {0001} ZnO substrates

H. Wenisch1,2, V. Kirchner3, Y. Chen1, S.K. Hong1, H.J. Ko1, T. Yao1
1Institute of Material Research, University of Tohoku, Sendai, Japan
2Tohoku Daigaku, Sendai, Miyagi, JP
3Inst. for Mater. Res., Tohoku Univ., Sendai, Japan

Tóm tắt

We present our first results for the growth of ZnO layers by Molecular Beam Epitaxy on commercial {0001} ZnO substrates of different polarities. On O-face oriented substrates, a two-dimensional growth mode was achieved as verified by the presence of a streaky Reflection High-Energy Electron Diffraction (RHEED) pattern and a faint (3/spl times/3) reconstructed surface. Moreover, a distinct specular spot and reproducible RHEED oscillations were found. On the other hand, the RHEED pattern for the growth on Zn-face ZnO substrates was spotty indicating three-dimensional growth, and a lateral coherence length of the layer of only 88 nm was estimated by Williamson-Hall plots. Bound exciton lines in low temperature photoluminescence for a layer on an O-face ZnO substrate were narrow (FWHM: 1.8 meV) compared to the substrate material, while the root mean square roughness measured by Atomic Force Microscopy was 20 nm.

Từ khóa

#Zinc oxide #Substrates #Atomic measurements #Force measurement #Atomic force microscopy #Molecular beam epitaxial growth #Optical reflection #Electrons #Diffraction #Surface reconstruction

Tài liệu tham khảo

cantwell, 2001, 13 Intern Conf on Crystal Growth and the 11 Intern Conf on Vapor Growth and Epitaxy 0, Projects of Cermet Inc 10.1080/01418619808221225 zhu, 2000, Abstractbook of the Twelth American Conference on Crystal Growth and Epitaxy 10.1063/1.1288159 10.1016/S0022-0248(00)00059-2 10.1063/1.125817 10.1016/S0022-0248(01)00932-0 zhu, 2000, Extended Abstracts of the 2000, Workshop on the Physics and Chemistry of II-VI Materials, 117 ko, 2000, J Cryst Growth, 209, 816, 10.1016/S0022-0248(99)00726-5 10.1016/S0022-0248(99)00610-7