News Briefs - Hardware:

NIST Helps Chip Industry Measure Features By Counting Atoms

The quest to develop the nanotechnology equivalent of rulers--length- measurement references based on the spacing of atoms in a perfectly ordered crystal--has inspired a burst of innovation at the National Institute of Standards and Technology (NIST). Progress to date has yielded a novel device that can resolve distances smaller than the radius of an atom and a reliable method for writing 10-nanometer-sized features on silicon. NIST researchers are packaging the new technology and know-how into a scanning tunneling microscope (STM) system designed to write patterns with dimensions determined by counting the atoms that make up the patterns' structural features. Ultimately aiming for an accuracy of better than 1 nanometer, the team intends to supply the semiconductor industry with benchmark references to calibrate measurement tools used in research and production.

To measure exceedingly small distances, members of the "atom-based artifacts project" developed a novel diode-laser based interferometer. The new, compact instrument incorporates elements of two types of existing interferometers-- devices that determine the distance between two objects on the basis of light interference patterns--but achieves much higher levels of resolution. To date, the team has measured distances in increments smaller than 10 picometers, or less than one-hundredth of a nanometer.

Efforts to produce durable, silicon-based measurement references have paid off with a method for reliably writing patterns with 10-nanometer linewidths-- equivalent to about 30 silicon atoms across. These STM-written patterns are long-lived, even outside of a vacuum, and recent work suggests that reactive ion etching can increase their three-dimensional relief.