AVS 53rd International Symposium
    Advanced Surface Engineering Wednesday Sessions
       Session SE-WeM

Paper SE-WeM5
Formation of Al Nanowires by High Temperature Glancing Angle Deposition

Wednesday, November 15, 2006, 9:20 am, Room 2007

Session: Glancing Angle Deposition
Presenter: M. Suzuki, Kyoto University, Japan
Authors: M. Suzuki, Kyoto University, Japan
K. Nagai, Kyoto University, Japan
K. Nakajima, Kyoto University, Japan
K. Kimura, Kyoto University, Japan
T. Okano, KOBELCO Research Institute, Inc., Japan
K. Sasakawa, KOBELCO Research Institute, Inc., Japan
Correspondent: Click to Email
It is well known that the physical origins of the columnar structure in obliquely deposited thin films are the self-shadowing effects and the limited mobility of the deposited atoms. In order to keep the mobility at low value, the substrate temperature was kept as low as possible in most works on the morphology control by oblique deposition. Recently, some peculiar properties for the crystallographic orientation@footnote 1@ and the compositional distribution@footnote 2@ in the obliquely deposited thin films have been reported. These works suggests that the novel/metastable phases can be expected to grow by controlling the mobility of obliquely deposited adatoms. However, it is not easy to predict the growth mode for the high temperature oblique deposition, since conventional crystal-growth theories treat only the case in which the atoms are supplied homogeneously. In this work, we investigated experimentally the growth of obliquely deposited Al films on a high temperature substrate. Al was deposited onto a Si or glass substrate held at a temperature of RT-400 °C at a deposition angle @alpha@=58-85°. Average thickness of deposited Al was 72-78 nm for all samples. The ordinary oblique columnar structures, which were observed in the films deposited at RT, completely disappeared for the samples deposited at 400 °C and the rugged granular structures were formed. In addition to the grains, we found nanowires of 30-300 nm in diameter and > 0.5 µm in length for the samples deposited at alpha > 73°. TEM observations clarified that these nanowires were single crystalline aluminum. The number and the size of nanowires increased with increasing @alpha@. This indicates that the shadowing effect plays an important role even at the high temperature region, where the mobility of adatoms becomes high. @FootnoteText@ @footnote 1@ T. Karabacak et al., Appl. Phys. Lett., 83 (2003) 3096.@footnote 2@ S. Jomori et al., Mater. Res. Soc. Symp. Proc., 849 (2005) 127.