A Bell Labs research team may have extended the life of silicon- based transistor chip designs by removing one of the barriers to further shrinking the width of a transistor. David Muller, a materials physicist at Bell, the R&D arm of Lucent Technologies says that their work may help extend the life expectancy for silicon-based transistor technology to 2012. Researchers had been predicting that at the current speed of development, totally new semiconductor technologies would be needed by 2005.
The Bell Labs researchers have produced a five-atom-thick gate oxide insulating layer – made of silicon dioxide – which determines the distance between the gate electrode and the channel, so determining the width of the channel inside a transistor. In today’s transistors, the gate oxide insulating layer is 25 atoms thick, and the channel is generally 250 or 180 nanometers wide. With the ultra-thin insulating layer, the size of the channel would be around 16 nanometers. Muller said that by the time his research efforts had been utilized, in 10-to-12 year’s time, chips would running at a clock speed of 10-to-20GHz – a 10 or 20 times performance hike on today’s 1GHz prototype chips from companies such as Intel Corp and Samsung Corp.
However, Muller said that were issues to be addressed before the research would trickle down into chip production. The Bell Labs team have only made around a million transistors with the new insulating layer, and Muller estimated that around two billion would be used in a semiconductor. What we still have work out, he said, is how this research would be applied to mass production. In addition, Muller said, the new technique only addresses the width of the transistor channel and work would need to be done on lithography techniques to reduce the height of the gate.
The team also showed that a four-atom layer is the fundamental physical limit for silicon dioxide-based insulators, so an alternative insulating material must be found before 2012. Muller said that gate oxide insulation of less than four atoms leaked current.
