Texas Instruments (TI) says it's working on digital signal processors (DSPs) and processors that are wired together with copper and a special material called "xerogel," which will eventually allow TI to cram 500 million transistors on a chip. By contrast, today's desktop processors contain between 5.5 and 7.5 million transistors.
Copper conducts electricity better than aluminum, the metal traditionally used for microprocessors, and is seen as an essential technology for reducing chip size and increasing performance. TI's announcement follows similar developments in chip-making technology from IBM (IBM) and Motorola (MOT). Analysts expect most chip makers to have "copper chips" by the end of the decade.
The news is "more or less inevitable. It's one of those changes that happens in the industry," said Jim Turley, an analyst with MicroDesign Resources. "Chips are getting fast enough that aluminum is outliving its usefulness," he explained.
Basically, the move to copper technology means that the industry can stay on its rapid pace of change, but not accelerate the rate of advancements, he summarized.
Chip designers and manufacturers have been packing more and more transistors onto smaller devices for decades, but they expect to soon hit a "speed limit" of around 400 MHz imposed by aluminum's physical properties. While aluminum has been the mainstay metal for decades, it won't be able to conduct enough power as chips become smaller and smaller. With copper technology, chip makers expect to be able to eventually produce processors with clock speeds of 1GHz (1,000 MHz).
"Even copper won't last forever. In about five years the industry will have to move again, probably to gold," according to Turley.
Copper has yet not been used in chip manufacturing because it is difficult to work with at the extremely small dimensions (.20 microns and lower) and can contaminate the transistors on a chip. TI says xerogel will prevent this contamination and allow it to manufacture circuits as small as .10 microns. Another benefit of xerogel is its ability to prevent electrical signals in the chip from degrading, a problem which eventually results in inaccurate calculations.
TI is already using xerogel and copper circuits in some of its products, according to Robert Havemann, a manager with the company. However, using the two together is a first for TI. The company expects to produce chips with the two technologies within the next five years.
Motorola expects to use its copper chip process first in limited numbers of workstation-class processors by early spring or summer of 1998. IBM has said it will manufacture new ASIC chips in volume for its Original Equipment Manufacturer (OEM) customers by January 1999.