AVS 53rd International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP22
Characterization of Orientation-Selective-Epitaxially Grown CeO@sub 2@ Layers on Si(100) Substrates by X-Ray Diffraction and Cross-Sectional Transmission Electron Microscopy

Tuesday, November 14, 2006, 6:00 pm, Room 3rd Floor Lobby

Session: Surface Science Poster Session
Presenter: T. Inoue, Iwaki Meisei University, Japan
Authors: T. Inoue, Iwaki Meisei University, Japan
S. Shida, Iwaki Meisei University, Japan
K. Kato, Fukushima Technology Centre, Japan
Correspondent: Click to Email
Orientation-selective-epitaxial (OSE) growth of CeO@sub 2@(100) and CeO@sub 2@(110) layers on Si(100) substrates is found to be capable by controlling substrate bias and plasma power in reactive dc magnetron sputtering. Although we have obtained a rough growth condition map to select growth orientation,@footnote 1@ at present, the detailed mechanism of OSE is not yet fully understood. In order to get insight into the origin of OSE, we characterized OSE grown CeO@sub 2@ layers using XRD and XTEM. The OSE growth procedure utilizing a two step growth method has been reported.@footnote 2@ Firstly, we carried out XRD measurements to study the orientation components of the epitaxial layers as a function of substrate bias. Analyses of (200) and (220) peak intensity variations with substrate bias proved that (100)-oriented growth regions exist at around ±15 V bias with a half width of 5 V. In the other regions, (110)-oriented CeO@sub 2@ layers grow. In the vicinity of the border of the two orientation regions, XRD data contained both peaks and their intensity ratio reversed across the border. Secondly, we made XTEM observations. Lattice images of CeO@sub 2@(100)/Si(100) structure indicated following two facts. One is that lattice rows of CeO@sub 2@(100) inclined compared with those of Si(100), wherein defects such as dislocations were scarcely seen. The other is that no interfacial amorphous layers are seen when the Ce-silicide layer thickness is adequate, which indicates the advantage of the two step growth method. This is very exciting, since amorphous interfacial suboxide layers have been thought to beinevitable. A part of this work was conducted in AIST Nano-Processing Facility, supported by "Nanotechnology Support Project" of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. @FootnoteText@ @footnote 1@ T. Inoue et al., J. Cryst. Growth, 271, 176 (2004).@footnote 2@ T. Inoue et al., J. Vac. Sci. Tehcnol. A 22(1), 46 (2004).