07 January 2012

Another Reprieve for Moore's Law

Current semiconductor line widths are pushing 20nm, or less than a dozen copper atoms wide.  But just as pinching a hose reduces its flow, the narrowing of current traces on microchips has suggested the impending end of the exponential increase in integrated-circuit densities known as Moore's Law.

Not so fast.  As reported in "Ohm’s Law Survives to the Atomic Scale" in Science v. 335 n. 6064, interconnects with the current-carrying capacity of today's copper traces can be formed by dotting four-atom-wide silicon pathways with phosphorus atoms:
We report on the fabrication of wires in silicon—only one atom tall and four atoms wide—with exceptionally low resistivity (~0.3 milliohm-centimeters) and the current-carrying capabilities of copper. By embedding phosphorus atoms within a silicon crystal with an average spacing of less than 1 nanometer, we achieved a diameter-independent resistivity, which demonstrates ohmic scaling to the atomic limit. 

Illuminating reporting is also available at Scientific American and Gizmodo.

Fascinating-- not only does the new technique offer a fresh order-of-magnitude for the progress of Moore's Law, it's nonmetallic!