MIT researchers have discovered a method of further reducing the width and resolution of etched lines by using an interference-generated optical mask as a kind of stencil pattern above the surface to be marked. The ability to create high resolution patterns is crucial to a variety of fields, including microchip manufacturing, biotechnology, and many other emerging branches of nanotechnology. By exploiting interference patterns created by light of differing wavelengths, a light sensitive material can be turned into an incredibly fine optical mesh that allows light through only in tiny parallel lines. Any material underneath can then be etched in a pattern of these fine lines with widths of about one-tenth the wavelength of the light itself -- a remarkable feat.

Read more at http://web.mit.edu/newsoffice/2009/nanopatterning-0409.html