How light can be used for making smaller, faster, cheaper computer chips

LONDON - University of Maryland researchers have found how they can use visible light to make tiny integrated circuits.

The find could one day, have implications for making ever smaller, faster, and cheaper computer chips.

Integrated circuits are made using a technique called photolithography. However, fitting more and more circuits on each chip has meant making smaller and smaller circuits.

Professor John Fourkas and his research group recently introduced a technique called RAPID lithography that makes it possible to use visible light to attain lithographic resolution comparable to (and potentially even better than) that obtained with shorter wave length radiation.

“Visible light is far less expensive to generate, propagate and manipulate than shorter wavelength forms of electromagnetic radiation, such as vacuum ultraviolet or X-rays. And using visible light would not require the use of the high vacuum conditions needed for current short wavelength technologies,” Fourkas said.

The idea is to use a ‘photoinitiator’ that can be excited, or turned on, by one laser beam and deactivated by another.

By combining a PROVE (proportional velocity dependence) photoinitiator with a photoinitiator that has a conventional exposure dependence, Fourkas and co-workers were also able to demonstrate a photoresist for which the resolution was independent of the exposure over a broad range of exposure times.

“Right now we’re using the technique for point-by-point lithography. We need to get it to the stage where we can operate on an entire silicon wafer, which will require more advances in chemistry, materials and optics. If we can make these advances-and we’re working hard on it-then we will think about commercialisation,” he said.

The study is published online by Nature Chemistry. (ANI)