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Etching Step (etching + step)

Distribution by Scientific Domains
Polymers and Materials Science60%
Physics and Astronomy40%

Selected Abstracts

Formation of Nickel Oxide Nanotubes with Uniform Wall Thickness by Low-Temperature Thermal Oxidation Through Understanding the Limiting Effect of Vacancy Diffusion and the Kirkendall Phenomenon

ADVANCED FUNCTIONAL MATERIALS, Issue 19 2010
Yi Ren
Abstract In this work, the step-wise oxidation mechanism of nickel (Ni) nanowires is elucidated. Rapid vacancy diffusion plays a significant role at low temperatures in forming heterostructures of nickel oxide (NiO) nanotubes with Ni nanowires. Subsequent investigations of Ni nanowire oxidation at higher temperatures and faster temperature ramp rates show that it is difficult to bypass this rapid vacancy diffusion stage, which affects the formation of the final structure. Therefore, it is unlikely to form solid NiO nanowires or NiO nanotubes with uniform wall thickness through the conventional annealing/oxidation process of Ni nanowires. Instead, a step-wise oxidation process by combining low temperature oxidation with a chemical etching step is utilized to produce for the first time NiO nanotubes with uniform wall thickness from Ni nanowires. [source]

Ordered Arrays of Mesoporous Microrods from Recyclable Macroporous Silicon Templates,

ADVANCED MATERIALS, Issue 16 2006
X. Chen
Ordered arrays of freestanding mesoporous microrods (see figure) are obtained from macroporous silicon templates with hydrophobized pore walls. The microrods can be removed from the template by simple mechanical lift-off. Since no wet-chemical etching step is involved, condensation of the rods is avoided and the template can be recycled. The hierarchical structures combine features on the nano- and microscale and have a well-controlled geometry. [source]

X-ray characterization of periodic sub-nm surface relief gratings

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2007
P. Zaumseil
Abstract Line and cross lattices of 260 and 360 nm pitch were prepared by covering p-doped Si(100) substrates with photoresist, structuring and implanting with 3 × 1015 cm,2, 45 keV As+ ions. These doping lattices with n+,p periodicity were investigated by X-ray diffraction (XRD) and reflectivity (XRR). While XRD did not show any signal of the periodic structure, XRR revealed a clear periodic diffraction pattern related to the pitch of the doping lattice. The features of this pattern as a function of the lattice orientation are discussed in detail for the cross lattice. Atomic force microscopy showed that the measured diffraction pattern is caused by a surface relief grating with sub-nm amplitude, which was generated by a final doping-dependent etching step during sample preparation. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Creating Anti-Reflective Nanostructures on Polymers by Initial Layer Deposition before Plasma Etching

PLASMA PROCESSES AND POLYMERS, Issue S1 2009
Irmina Wendling
Abstract The generation of nanostructures by initial layer deposition and plasma etching offers a simple and cost-effective method for imparting broadband anti-reflection properties to polymer optics. In this study, we have investigated the possibility of controlling the structure growth on the cycloolefin polymer Zeonex®. It has been found that the geometry of the emerging nanostructures can be adjusted from "island-like," through "sponge-like," to "pinholes" merely by changing the thickness of the initial layer before the etching step. However, not all structure types provided a satisfactory transmittance enhancement. Only when the initial layer thickness and the etching time were matched in such a way that a certain material/air filling factor range and a sufficient structure depth were obtained could an outstanding anti-reflection effect be realized. [source]

Fabrication of porous ZnO nanostructures and morphology control

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2007
Sang Hyun Lee
Abstract Porous ZnO nanostructures were easily fabricated by annealing and etching of as-grown ZnO nanorods using an aqueous solution method at low temperature. The density of ZnO nanorods was changed by repetition of coating and drying of zinc acetate hydrate in ethanol. The annealing process is a very critical step to make porous ZnO nanorods because nano-sized pore are formed at this step. Without annealing, pores could not be observed at the surface of ZnO nanorods. Furthermore, pore the size gets larger in etching steps following the annealing. The structural and optical properties for porous ZnO nanostructures were investigated using TEM and PL. Porous ZnO nanostructures were grown along the c-axis and pores were distributed in the whole body. PL intensity was increased by annealing and etching. This is ascribed to the improved crystallinity and large surface area. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]