Last week, IBM trumpeted that it had found a way to use copper chip circuits. Copper conducts electricity better than aluminum, the metal traditionally used for microprocessors, and contributes to reducing chip size.
Motorola says it has independently developed a similar process for chip manufacturing, called "dual-inlaid metallization," which will allow processor speeds of up to 1000 MHz (1 GHz), according to Fabio Pintchovski, director of Motorola's Advanced Product Research and Development Laboratory.
Both Motorola and IBM jointly develop the PowerPC architecture at the Somerset Design Center in Austin, Texas, but separately manufacture PowerPC processors for Macintosh computers and other applications.
According to Pintchovski, Motorola will use the process first in workstation-class processors such as the PowerPC 604e and also the recently introduced PowerPC 750. He expects the company will be shipping sample quantities of the chips by early spring or summer of 1998 to OEM customers.
Though chip designers and manufacturers have been cramming more transistors onto smaller devices for decades, 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.
Copper has not been used in chip manufacturing yet because it is difficult to work with at the extremely small dimensions (.20 micron and lower) and can contaminate the transistors on a chip. Motorola and IBM say they have found a way to get around these problems, possibly giving rise to chips with 50 to 100 million transistors on a single chip. By contrast, today's desktop processors have between 5.5 and 7.5 million transistors.
Intel is attempting to come up with a method for making semiconductor circuits out of metals other than aluminum, but expects to develop two more generations of microprocessors before it is able to use new manufacturing methods.
Both Motorola and IBM say that the new process will eventually be used throughout their entire line of chip products. The companies recently announced that they were increasing their focus on non-PC markets for the PowerPC architecture.