Home  About us  Contact
 

Interpore Distance (interpore + distance)

Distribution by Scientific Domains
Physics and Astronomy75%

Selected Abstracts

Controlled Fabrication of Multitiered Three-Dimensional Nanostructures in Porous Alumina,

ADVANCED FUNCTIONAL MATERIALS, Issue 14 2008
Audrey Yoke Yee Ho
Abstract We present the fabrication of multitiered branched porous anodic alumina (PAA) substrates consisting of an array of pores branching into smaller pores in succeeding tiers. The tiered three-dimensional structure is realized by sequentially stepping down the anodization potential while etching of the barrier layer is performed after each step. We establish the key processing parameters that define the tiered porous structure through systematically designed experiments. The characterization of the branched PAA structures reveals that, owing to constriction, the ratio of interpore distance to the anodization potential is smaller than that for pristine films. This ratio varies from 1.8 to 1.3,nm,V,1 depending on the size of the preceding pores and the succeeding tier anodization potential. Contact angle measurements show that the multitiered branched PAA structures exhibit a marked increased in hydrophilicity over two-dimensional PAA films. [source]

Microstructured horizontal alumina pore arrays as growth templates for large area few and single nanowire devices

PHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 2 2008
Ying Xiang
Abstract We demonstrate the fabrication of horizontally aligned and well-defined nanopore structures by anodic oxidation of aluminum thin films and micro stripes on a Si substrate. We are able to control both, the pore diameters and interpore distances from 10 nm to 130 nm and from 30 nm to 275 nm, respectively. The anisotropy of the system induces some deviations in the pore configuration from the typical honeycomb structure. By decreasing the dimensions of the Al structures, the final pore diameter and interpore distance remains constant, enabling the transition from multiple to a few nanowire porous structures. Finally, we successfully filled the nanopores by pulsed electroplating, as demonstrated both by Scanning Electron Microscopy and by current,voltage measurements. Having full control over the size, the density, the position and the orientation of the porous structure, our approach is promising for many exciting applications, including nanoelectronics and sensing. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

SU8 photoresist as an etch mask for local deep anodic etching of silicon

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2003
V. V. Starkov
Abstract For the formation of an ordered porous structure, the distance between two nearest neighbor pores cannot be more than a certain size, otherwise random nucleated pores arise spontaneously between ordered pores. The "proximity effect" does not allow the production of macropores with variable interpore distances on the surface of Si wafers. More precisely, it does not allow one to increase arbitrarily the distance between single pores, which is necessary, for example, in the manufacture of photovoltaic devices with improved radiation hardness. Moreover, for many electronic, electromechanical, and optical applications, it is highly desirable to pattern porous silicon in defined two- and three-dimensional geometrical layouts. The simplest solution to such problems is anodic etching through a photoresist mask. In the present work, results on deep anodic etching of silicon through a mask of SU8 photoresist are presented. [source]