Two companies claimed today to have emulated IBM’s achievement and discovered techniques for making semiconductors and microprocessors with copper instead of aluminum. The move is likely to lead to a rush by manufacturers to adopt the new technology which opens the prospect of a vast increase in processing speeds with much lower power consumption. Applied Materials Inc, which boasts it is the world’s largest supplier of wafer fabrication systems, launched what it describes as the industry’s first system for depositing the critical barrier and seed layers for copper interconnect circuitry. But Texas Instruments Inc claims to have gone one better with a combination of copper and the powerful insulating material xerogel in an integrated circuit. It says this approach, which leapfrogs simple copper circuitry, will lead to digital signal processors and microprocessors which are ten times faster and use less power than today’s most powerful chips. Texas says its technologies solve the looming problem with the next generation of chips that devices will become so small and close together that the wire connections between transistors can slow the flow of electrical signals between the wires. This would severely degrade the performance of the chip. But by coupling copper and xerogel, a substance made of microscopic glass bubbles containing air, TI says electrical signals can flow more freely throughout a chip. Xerogel may be the ultimate solution because it has the lowest dielectric constant known other than air, said Trobert Havemann, manager of advanced Interconnect Development at TI. In September, Sematech, the US semiconductor industry research consortium, announced it had successfully integrated the use of copper interconnect wires with an insulating material, which it refused to disclose. (CI No 3,236) Applied Materials’ system, based on its Ion Metal Plasma Technology, deposits a tantalum nitride barrier layer on the chip, followed by a thin seed layer of copper. The barrier and seed layers enable the volume production of copper-based semiconductors, said Dr Ashok Sinha, who heads the company’s Metal Deposition group. The rush is now on to get the first copper chips onto the market. Motorola Inc said in September it had been working on a copper process for two years and plan to ship its first chips later next year. IBM is building a $700m facility for 300mm copper chips which will be available in late 1999 (CI No 3,295). While IBM is willing to make chips for third parties, it will not license its technology.
