Straining forward
Computers keep getting more powerful because silicon transistors keep getting smaller. But that miniaturization can’t continue much further without a change to the transistors’ design, which has remained more or less the same for 40 years.One potential successor to today’s silicon transistors is silicon nanowires, tiny filaments of silicon suspended like the strings of a guitar between electrically conducting pads. But while silicon nanowires are certainly small enough to keep the miniaturization of computer circuitry on track, there’s been doubt about whether they can pass enough electrical current for high-speed computing. At 2008’s International Electron Device Meeting, researchers at MIT’s Microsystems Technology Laboratories demonstrated silicon nanowires with twice the electron mobility — which indicates how easily current can be induced — of their predecessors. Now, the same group has shown that they can build chips in which up to five high-performance nanowires are stacked on top of each other. That...