By Kate Concannon
IBM scientists claim they have built the first array of transistors out of carbon nanotubes, in a move to take the silicon out of silicon chip technology.
IBM has announced a significant achievement in the development of chip technology: for the first time, an array of transistors has been made successfully using carbon nanotubes. These elongated molecules, formed randomly from hexagonal arrays of carbon atom, are 50,000 times thinner than the diameter of a human hair — which equates, in turn, to an impressive one-fiftieth the width of the silicon circuits achievable with current 0.1 micron technology.The material has been known to scientists since the early 1990s, and three years ago scientists managed to produce single transistors using the nanotubes. But it is only now the process has been sufficiently refined to deliver the accuracy and precision crucial to production feasibility. The IBM scientists managed to produce electronic switches out of nanotube wires the size of only 10 atoms — or 1.4 nanometers. The same component in many transistors built today, on the other hand, measures about 500 nanometers. The field of molecular electronics is burgeoning in the race to replacing silicon. Despite the confidence with which chip developers such as Intel are facing the task of keeping up the pace set by Moore's Law, it is generally believed that silicon-based technology will have reached its limit in the next few years. Developments such as ultra-violet light lithography are expected to extend these limits to 2005 — and possibly some time beyond — but finding materials that can pack more power into ever smaller spaces and run on less energy is key to the long term future of chip development.