MRS Proceedings

Articles

Influence of Momentary Annealing on the Nanoscale Surface Morphology of Room Temperature Pulsed Laser Deposited NiO(111) Epitaxial Thin Films on Atomically Stepped Sapphire (0001) Substrates

2012 MRS Fall Meeting.

Ryosuke Yamauchia1, Geng Tana1, Daishi Shiojiria1, Nobuo Tsuchiminea2, Koji Koyamaa3, Satoru Kanekoa1a4, Akifumi Matsudaa1 and Mamoru Yoshimotoa1

a1 Department of Innovative and Engineered Materials, Tokyo Institute of Technology, Yokohama 226-8502, Japan

a2 Toshima Manufacturing Co., Ltd., Higashimatsuyama, Saitama 355-0036, Japan

a3 Namiki Precision Jewel Co., Ltd., Adachi, Tokyo 123-8511, Japan

a4 Kanagawa Industrial Technology Center, Ebina, Kanagawa 243-0435, Japan

ABSTRACT

We examined the influence of momentary annealing on the nanoscale surface morphology of NiO(111) epitaxial thin films deposited on atomically stepped sapphire (0001) substrates at room temperature in O2 at 1.3 × 10−3 and 1.3 × 10−6 Pa using a pulsed laser deposition (PLD) technique. The NiO films have atomically flat surfaces (RMS roughness: approximately 0.1–0.2 nm) reflecting the step-and-terrace structures of the substrates, regardless of the O2 deposition pressure. After rapid thermal annealing (RTA) of the NiO(111) epitaxial film deposited at 1.3 × 10−3 Pa O2, a periodic straight nanogroove array related to the atomic steps of the substrate was formed on the film surface for 60 s. In contrast, the fabrication of a transient state in the nanogroove array formation was achieved with RTA of less than 1 s. However, when the O2 atmosphere during PLD was 1.3 × 10−6 Pa, random crystal growth was observed and resulted in a disordered rough surface nanostructure after RTA.

Key Words:

  • film;
  • annealing;
  • morphology
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