Nanofabrication via atom optics

Owing to the continuing reduction in the scale of microelectronic and micromagnetic technology, new microfabrication methods are constantly being explored. This is particularly true in the case of nanostructure fabrication. Here, the phenomenon of optical diffraction limits the resolution obtainable by exposing a photoresist to a pattern of light, as is done in conventional lithography. We are investigating a different paradigm. Since both light and matter can be thought of as waves, instead of focusing light waves with objects made of matter, why not focus matter waves with objects made of light? To accomplish this we use lasers to form lenses from optical waves. These lenses focus a beam of neutral atoms prior to the atom’s deposition on a silicon substrate. In this way, we have fabricated chromium structures consisting of thousands of parallel lines or millions of dots with dimensions as small as 28 nanometers. We describe the basis of this new technology, present examples of its application to date, detail its advantages and limitations, and discuss the future of optical nanostructure fabrication. q1999 Elsevier Science B.V. All rights reserved.