Ibm In Copper Semiconductor Breakthrough

International Business Machines said Tuesday it had achieved a breakthrough in the manufacture of computer chips by using copper, instead of aluminium, for the metallic circuitry linking transistors on a semiconductor.

IBM said the technology would enable it to shrink electronic circuitry and fit more computer logic on to a chip. The companys shares jumped more than 5 per cent on the news and in early trading yesterday in New York gained $5 3 /8 to $104 5 /8.

IBM is the first chipmaker to develop a commercial manufacturing process using copper. Copper has long been known to be a better conductor of electricity than aluminium, which is why copper is used in household electrical wiring.

However, early in the development of semiconductor chips it was found that copper tended to leach into the surrounding silicon, making it difficult to use.

The industry therefore switched to aluminium. Now, with the dimensions of the microminiature circuit patterns on semiconductor chips becoming ever smaller, the industry is reaching the limits of aluminiums conductivity. Aluminium was becoming a real wall and breaking through this [wall] allows us to really push performance, said John Kelly, vice-president of technology in IBMs Microelectronics Group.

IBM Microelectronics plans to introduce the first products using the copper technology later this year. These will be a new generation of application specific logic chips, a chip designed for one specific use. Other chipmakers have been researching the use of copper.

Sematech, the US semiconductor research consortium, announced this year that it had produced laboratory samples of chips using copper. Most US chip makers are not rushing to adopt the technology. Intel, for example, hopes to be able to postpone the use of copper until the early 2000s. Copper is more difficult to use because it must be insulated from the silicon, Intel explained.

That leads to a more complex manufacturing process. We all know that we are going to have to switch to copper ultimately, but we will not switch until we have to, Intel said.

IBM hopes to gain a performance advantage for its chips by adopting copper in advance ofother chip makers.

The new manufacturing process would yield significant performance gains, IBM said. Consumers will benefit from the new technology which allows more computer intelligence to be built into products that are smaller, integrate more complex functions, use less power and require less cooling, IBM said.

The company expects the new chips to be used in mobile phones, hand-held computers and a plethora of new types of electronic products. World stocks, Page 43 Copyright Financial Times Limited 1997. All Rights Reserved.