A refined method developed at the National Institute of Standards and Technology (NIST) for measuring nanometer-sized objects may help computer manufacturers more effectively size up the myriad tiny switches packed onto chips’ surfaces. The method, which makes use of multiple measuring instruments and statistical techniques, is already drawing attention from industry.

Nothing in life may be certain except death and taxes, but in the world of computer chip manufacturing, uncertainty is a particularly nagging issue, especially when measuring features smaller than a few dozen nanometers. Precision and accuracy are essential to controlling a complex and expensive manufacturing process to ensure the final chips actually work. But features on modern chips are so tiny that optical microscopes cannot make them out directly. Metrologists have to use indirect methods, like “scatterometry”—deducing their shape from sampling the pattern light created as it scatters off the features’ edges. When this isn’t enough, there’s atomic force microscopy (AFM). It's expensive and slow, but it can give distinct measurements of the height and width of a nanoscale object while light scattering occasionally has trouble distinguishing between them.

 …