IBM announced today that it will soon begin producing microprocessor chips that it says could boost operating speeds by 25% and overall chip performance by more than a third. In addition to being faster, the new chips are expected to use about a third less electricity than today's microprocessors, extending battery life for portable devices such as cellular phones and hand-held computers.
The key change comes in the base on which transistors and other chip-based circuitry sit. Conventional microprocessors are built atop a slab of crystalline silicon. In the new chips, that thick slab is reduced essentially to a thin silicon film. For transistors to switch on they must electrically "charge up" the silicon underneath them. That's a time-consuming and energy-draining process for conventional "thick slab" chips, but the thin silicon layer allows silicon-on-insulator (SOI) chips to charge up much more quickly and efficiently.
While IBM's announcement is sure to rock the chip-making world, SOI is hardly new. The technology has been around for 30 years, and is already used in chips for niche applications, such as those aboard satellites, as well as some types of computer memory chips. To make the technology viable for mass-producing microprocessors--the high-end chips that serve as the brains of computers--IBM says it solved key hurdles in producing defect-free thin silicon films.
The new announcement "is very exciting" says Ken Goodson, a chip expert at Stanford University who has worked extensively on SOI. The semiconductor industry has long recognized the advantages of SOI technology, says Goodson. But because conventional chips were improving at such a rapid pace, there was no need to switch to alternatives, he adds. In recent years, however, the rate of improvement in conventional chips has begun to taper off, a trend that shows no sign of abating. "Now it suddenly makes sense to make the shift," says Goodson.