source : http://www.technologyreview.com/articles/rnb_092903.asp 

Process Orders Nanowire Arrays

Technology Research News  September 29, 2003

Harvard University researchers have found a way to neatly layer and pattern 

rows of nanowires. 

The method is a step toward using the microscopic wires to build electronics 

components from the ground up rather than the usual top-down approach of 

photolithography, which uses light and chemicals to etch components into 

chips made from semiconductors like silicon.

The researchers used nanowires that were 45 and 90 nanometers in diameter. 

A nanometer is the span of 10 hydrogen atoms. The arrays could be used to 

form devices like nanoscale light-emitting diodes and densely-packed 

computer chips.

The researchers used a previously reported technique to align a layer of 

nanowires in solution, and formed structures of parallel or crossed nanowires 

by transferring each layer to a surface, or substrate. They then used 

photolithography methods to further pattern the nanowire structures into arrays 

of nanowire field-effect transistors.

The method allows for control of the orientation and spacing of the nanowires, 

and the orientation, size and spacing of the arrays that form each layer of the 

structure. This makes it possible to construct practical electronic devices from 

nanoscale components like nanowires.

The researchers are working on making more complicated arrays, and ways 

to interconnect the wires.

Some applications, like nanosensor arrays and large-scale electronic 

devices, could be practical within two years, according to the researchers. 

The work appeared in the September 10, 2003 issue of Nano Letters.