New Method Could Lead To Narrowing Lines On Microchip: MIT

Rajesh Menon, research engineer, research laboratory of electronics, and graduate students Trisha Andrew in the department of chemistry and Hsin-Yu Tsai in the department of electrical engineering and computer science -- have found a novel method for etching extremely narrow lines on a microchip, using a material that can be switched from transparent to opaque, and vice versa, just by exposing it to certain wavelengths of light.
The new technique, which the researchers call absorbance modulation, makes it possible to create lines that are only about one-tenth as wide as the wavelength of light used to create them. Part of the trick was to find a suitable photochromic material whose clear and opaque parts would remain stable after the initial exposure to light.

Using this method, the team produced lines just 36 nanometers wide, and say they could also place many such lines spaced a similar distance apart.

Producing such fine lines is crucial to many new technologies, from microchip manufacturing that is constantly seeking ways to cram more components onto a single chip, to a whole host of emerging fields based on nano-scale patterns. But these technologies have faced fundamental limits because they tend to rely on light to produce these patterns, and most techniques cannot produce patterns much smaller than the wavelengths of light itself. This method is a way of overcoming that limit, sais the researchers.

Such a technique could "could have a significant impact on chip making," Menon says, and could also help to enable new work in a variety of emerging fields that rely on nano-scale patterning, including nanophotonics, nanofluidics, nanoelectronics, and nano-biological systems.

Already, a company has been formed to develop this technology, and Menon said he expects it to lead to commercial production within five years.

But that's not the only potential application of the approach. Menon explained that his team is pursuing possible use of the same system for imaging systems, which could enable new kinds of microscopes for observing at nanoscale resolution, with possible applications in biology and in materials science. At the same time, he is pursuing ways of using the technique to create even smaller patterns, down to the scale of individual molecules.