IBM has released more details about the manufacturing process used to create its first 90-nanometre chip - the PowerPC 970FX.

The 90nm process technology is a blend of strained silicon, silicon on insulator (SOI) and copper wiring, IBM said, adding that samples of the 970FX chip have already shipped and that production volumes are increasing.

Apple will be the first customer for the new chip. IBM and Apple confirmed that the XServe G5, announced in January at MacWorld, will use the 970FX. Apple will probably adopt the chip for a new series of PowerMac desktops to be released later this year.

The processor is similar to AMD's Athlon 64 chip in that it allows Apple users to run both 32 and 64-bit applications on the same chip. Customers will be able to use the chip in everything from PCs to notebooks to networking equipment, said Norman Rohrer, senior technical staff member at IBM.

The company claims that the chip's unique power-tuning technique allows it to vary power consumption thousands of times per second, reducing the overall power consumption compared with other chips that consume a constant amount of power.

IBM's strained silicon manufacturing technique involves a layer of nitrate that wraps around the silicon transistors. The atoms in the two substances naturally align when placed together, and that process actually stretches the silicon channel through which electrons flow. More electrons can flow down the channel if the opening is wider, and more electrons equals more performance.

Intel used a similar technique to create its newest Pentium 4 processor, formerly known as Prescott. Prescott was announced last week and is available in systems for major PC vendors.

One of the major concerns of chip designers at this process generation is current leakage. The tiny dimensions of today's silicon chips mean electrons can start to break through the features and leak out of the processor as heat. This heat can disrupt system performance and require expensive cooling solutions to manage.

To prevent current leakage, IBM has implemented SOI on its last two process generations. The SOI technique requires chip makers to build transistors on top of a silicon wafer that is coated with an insulating material such as silicon oxide.

SOI has been credited with reducing the power consumption of IBM's new 970FX chip. Under moderate operating conditions, the 970FX chip is expected to consume about 24.5W of power when clocked at 2GHz, according to internal IBM documents and analysts. This is about half of the power consumed by the PowerPC 970 chip at a slower clock speed.

The blend of the different manufacturing techniques gives IBM a unique chip that will appeal to very different customers, said Richard Doherty, research director at The Envisioneering Group. "[IBM's] manufacturing technique gives them the breadth that the chip can be a stump-pulling pickup truck or a high-mileage sports car," Doherty said. It can be used in high-performance computers like Apple's PowerMacs, or in the embedded networking equipment that helps route Internet traffic, he said.

IBM's 90nm process has also been remarkably free of the yield problems that affect most chip companies as they introduce a new process, he added.