The imaging is done with a digital CCD camera. The Nanostar Software calculates the intensity profile of the image. The CD value with best possible accuracy is calculated from this intensity profile with sub-pixel resolution using a predefined threshold.

The intensity profile has to be processed extensively to clean it from disturbing effects like statistical photon noise or deformations by optical diffraction effects. Remaining effects like pixel efficiency deviations, vignetting (shadowing), and remaining non-linearity are corrected by the software on the fly.

The CD value is calculated with sub-pixel resolution (< 1/10 of pixel size).

The secret of our ultra precise measurement technique is a combination of a very good hardware and perfect software algorithms. All of our systems use Leica microscopes with best optics and Laser autofocus possibility. The Nanostar Software is based on the experience from more than 200 systems worldwide.