Formation and Characterization of Striped Nano-Channel Structure on the Functional Oxide Thin Film
- PDF / 1,226,718 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 65 Downloads / 178 Views
0961-O15-02
Formation and Characterization of Striped Nano-Channel Structure on the Functional Oxide Thin Film Masayasu Kasahara1, Akifumi Matsuda1, Yasuyuki Akita1, Wakana Hara1, Keisuke Kobayashi2, Kazuyoshi Kobayashi2, Toshimasa Suzuki2, and Mamoru Yoshimoto1 1 Innovative & Engineered Materials, Tokyo Institute of Technology, 4259-R3-6, Nagatsuta, Midori, Yokohama, 226-8503, Japan 2 Taiyo Yuden Co.Ltd., 5607-2, Nakamurota, Takasaki, 370-3347, Japan
ABSTRACT The striped nano-channel structure (about 10nm in depth) was formed on the NiO film surface by thermal annealing of the film deposited on the sapphire(0001) substrate with periodic straight atomic steps. The interval of each nano-channel was about 100nm on average and well corresponded to the separation of atomic steps on the used sapphire(0001) substrate. Effects of annealing temperature and impurity doping into NiO upon the nanochannel formation were examined in order to control the depth. The depth of nano-channels formed on the alkalimetal(Li or Na) doped NiO films was found to be larger than that of nano-channels on the non-
～ ℃
doped NiO films and enlarged with increasing annealing temperature in the range of 500 900 . Atomic-scale cross sectional structure of the nano-channel was characterized by transmission electron microscopy with focused on the film/substrate interface. INTRODUCTION
There has been great interest in fabrication of nanostructures with a wide range of applications that include quantum effect electronic devices, nano-electromechanical systems [1], patterned nanostructure for nanoimprint lithography [2] and so on. So far, a variety of nano-scale material design techniques involving machinery operation have been available, e.g. electronbeam lithography, nanoimprint lithography, focused ion beam processing, direct writing by scanning probe microscopes, etc [3]. On the other hand, nano-wires or nano-dots have been fabricated via self-assembly phenomena along the atomic steps on the vicinal surface of single crystal substrates [4]. These
～°
vicinal surfaces, which are placed at a small (0.1 1 ) angle to the crystallographic planes, were reported to result in the staircase surface with atomic steps after thermal annealing [5] or wet etching [6]. In the film growth on the atomically stepped substrate, the substrate steps are considered to induce such defects in the microstructure of the grown film as lattice displacement or lattice distortion along the direction of surface normal to the substrate [7-9]. Recently, we have found self-assembled formation of the nanochannel pattern on the oxide film grown on the atomically stepped sapphire( -Al2O3 single crystal) substrate [10]. Here we report the detailed formation process and nano-scale characterization of the striped nano-channel structure developed on the surface of NiO thin films.
α
EXPERIMENT The NiO-based oxide films were prepared on the ultra-smooth sapphire(0001) substrate by pulsed laser deposition method. The ultra-smooth sapphire(0001) substrate with atomically flat terraces
Data Loading...
