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IBM says its researchers have made a breakthrough in reducing the width of circuits on silicon chips to less than 30 billionths of a metre.
Scientists will tell a microlithography conference in San Jose on Monday they have been able to etch circuits that are only 29.9 nanometres wide. This is 3,000 times thinner than a human hair and one-third the size of the 90nm circuits currently dominating production in the chip industry.
Chipmakers are continually seeking to reduce the size of chip components and cram more transistors on to silicon as they extend the 40-year-old Moore’s Law. It predicts that the number of transistors on a chip will double every 18 months to two years. Achieving further miniaturisation can increase performance, reduce power consumption and create cost savings.
The industry has a target of reducing circuit widths from 90nm to 65nm-45nm, moving on to 32nm. Intel is leading the way with its processors now switching over to 65nm. But the industry has seen 32nm as the limit for existing optical lithography techniques – where ultra-violet light is beamed by lasers through stencils to “print” circuits on chips.
IBM’s Almaden Research Center and its Silicon Valley partner, JSR Micro, say they can now extend optical lithography with new “immersion” techniques, where the lasers pass through liquid with a high refractive index. This creates a sharper focus and allows the imaging of smaller features.
The development, which will need high-index lens materials to be developed to ensure its commercial viability, could put off a move to more expensive and still unproved methods that would use “soft x-rays” and mirrors to drive miniaturisation down to the next level of 22nm.
“Our goal is to push optical lithography as far as we can so the industry does not have to move to any expensive alternatives until absolutely necessary,” said Dr Bob Allen, manager of lithography materials at Almaden. “This result is the strongest evidence to date that the industry may have at least seven years of breathing room before any radical changes in chip-making would be needed.”