Thanks again to Steve Barker for this post. It seems that everyday we are hearing a new way to use carbon nanotubes and this latest way of utilising them for highly dense packaging of transistors will one day probably take over from the silicon based systems we use at present – Deskarati –
Researchers have developed a new way of producing very dense arrays of carbon nanotubes suitable for making complex integrated circuits.
Nanotube transistors have shown great promise in simple experimental prototypes, but making them into the complex circuits—needed for the chips that run computers and cell phones—has proven tricky. Researchers at Stanford University are using the new fabrication method to build ever more complex circuits that they hope will soon rival the speed of silicon.
For years, computer scientists have worried that, as they continue to miniaturize silicon transistors in order to cram more computing power in ever-smaller spaces, they will come up against the material’s physical limits. Many replacements are being explored, including exotic semiconductors and another form of carbon called graphene. For digital logic, though, many believe carbon nanotubes show the greatest promise. “No other material has shown the same ability to scale down as aggressively as carbon nanotubes can,” says Aaron Franklin, a researcher at IBM’s Watson Research Center in Yorktown Heights, New York. When silicon transistors are miniaturized to a comparable size scale, they become leaky and unstable.
However, making a single high-performance nanotube transistor is one thing; making a large array of nanotubes integrated into a circuit is quite another. In the past few years, researchers at Stanford have made some of the most complex nanotube circuits yet. They developed workarounds to overcome carbon nanotubes’ imperfections—the presence of metallic tubes amongst the semiconducting ones needed for transistors, for example. But these circuits were still relatively simple, performing arithmetic at about the level silicon circuits achieved in the 1960s.