Not just a chip off the old block!

Author:  Raechel Zipagan
Institution:  Boston University
Date:  June 2004

Researchers at Princeton University have developed a low-cost production method that may lead to greater memory capacity and lower costs for computers, digital cameras, and other consumer electronics. The research has been published in the June 28 issue of Applied Physics Letters.

The technique, termed nanoimprinting, was developed by Stephen Chou, Professor of Electrical Engineering at Princeton. The method entails pressing a mold into a layer of softened plastic on a silicon wafer, a small thin circular slice of a semiconducting material, to create microscopic impressions on the surface of the plastic. The patterns are then transferred to the silicon, where they may form the basis of miniature circuits that can store digital information.

"Advances in nanotechnology are presenting great opportunities for innovation and discovery in many engineering and scientific areas," says Chou. "This is because many conventional theories no longer apply in the nanostuctures of a dimension smaller than some fundamental physical length scales."

The goal of this research, led by Chou and colleague Stephen Lyon, Professor of Electrical Engineering, was to determine how small and densely a pattern could be pressed into plastic with nanoimprinting. The researchers created tall, thin ridges five nanometers wide (10 nanometers is 1000 times smaller than the diameter of a human hair). The small size of the ridges and the amount of space between them are equally important, as these features ultimately determine the amount of memory that can be stored on a chip.

This achievement is an advance over current technology, which involves expensive and time-consuming processes. Chou says that their findings could be used in making advanced computer chips with four hundred times more memory than current chips.