Nanostaircases: An atomic shadowing instability during epitaxial CrN(001) layer growth
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)
Epitaxial CrN(001) layers, 57 and 230 nm thick, were grown on MgO(001) at 700 deg. C by ultrahigh-vacuum magnetron sputter deposition in pure N{sub 2} discharges. An oblique deposition angle {alpha}=80 deg. was utilized to purposely increase the effect of atomic shadowing on surface morphological and microstructural evolution. The layers are single crystals with a surface morphology that is characterized by dendritic ridge patterns extending along orthogonal <110> directions superposed by square-shaped supermounds with <100> edges. The ridge patterns are due to a two-dimensional growth instability related to a gradient in the adatom density while the supermounds form due to atomic shadowing. The supermounds protrude out of the surface and capture a larger deposition flux than the surrounding layer. This leads to both vertical and lateral growth and the formation of inverted pyramids that are epitaxially embedded in a single crystalline matrix. The inverted pyramids are terminated by 1-3-nm-wide tilted voids that form nanostaircases due to kinetic faceting along orthogonal {l_brace}100{r_brace} planes.
- OSTI ID:
- 20702527
- Journal Information:
- Applied Physics Letters, Vol. 87, Issue 5; Other Information: DOI: 10.1063/1.2005369; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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