A team based at Nasa's Ames Research Center in California has developed a multi-walled carbon nanotube as the tip of an atomic force microscope.
The tip is designed to scan the surface of ICs to measure the dimensions of the surface features. The current method, using a diamond tip, is becoming problematic as feature sizes continue to shrink. The diamond tip cannot be reduced any further in size.
Dr Meyya Meyyappan, project director of devices and nanotechnology at Ames, said: "Industry people are saying they are having difficulties scanning at 0.13µm with diamond tips. They are going back to scanning electron microscopes, but it is difficult to gauge the depth.
"Companies with atomic force microscopes will be able to use the tips for profilometry and imaging."
As well as accurately scanning vias, trenches and holes, the tips can be used to assess the quality of thin films within ICs made from materials such as silicon nitride and gold.
Currently this is done with a silicon cantilever attached to the atom force microscope, but the tip often breaks or becomes blunt and the resolution of the information obtained is not ideal.
The Nasa team has developed a processing method whereby the nanotip is grown on to a carbon cantilever which is then easily attached to the microscope. The nanotube is more robust and therefore less likely to break. Its much reduced diameter also provides a greater sharpness of image.
A small company, Integrated Nanosystems, is planning to commercialise the production process.
"You will be able to buy the cantilever for about $20," said Meyyappan. "This advancement should make the atomic force microscope a standard diagnostic tool."