Motorola Labs Studying Carbon Nanotube Technology

TEMPE, Ariz., Oct. 21 -- Scientists at Motorola Labs are researching ways to improve control in the growth of carbon nanotubes (CNTs) that can make transistors smaller and faster and chemical/biological detectors ultrasensitive.

"CNTs can play a very significant role in the emergent technological area known as nanotechnology," said Ray Tsui, who leads the nanoelectronics research effort at Motorola Labs. "With diameters in the nanometer regime and a very high length-to-diameter ratio, CNTs have unique properties that can exploited to achieve extraordinary performance in a number of applications."

The Motorola Labs team is collaborating with researchers at Arizona State University to develop ultrasensitive chemical/biological sensors based on single-walled carbon nanotubes. Another group at Motorola Labs is researching the use of CNTs for high-brightness flat panel displays.

CNTs are a relatively new form of molecular carbon that was discovered only twelve years ago. Each nanotube is formed with one or more seamless concentric cylinders consisting of a rolled-up sheet of graphite. Early research indicates that CNTs have very promising mechanical and electrical characteristics, according to the researchers. Scientists studying CNTs have reported that they can be as much as 100 times stronger than steel at a fraction of the weight. Other studies showed that the metallic variety of CNTs has a current carrying capability more than 100 times that of copper, while the semiconducting variety can potentially be used for transistors that are smaller and faster than conventional ones made with silicon.

One of the technical challenges associated with CNT-based device technology is in controlling the placement of nanotubes with specific properties on a substrate. The Motorola Labs team has developed a technique using chemical vapor deposition that can position individual single-walled carbon nanotubes at predetermined locations on a substrate in a highly parallel manner that is compatible with conventional semiconductor processing techniques. Furthermore, the team found that almost 90 percent of these nanotubes are semiconducting in nature -- an important step forward in developing arrays of ultrasmall transistors using CNTs.

For more information, visit: www.motorola.com/labs