Chromatic dispersion profilometry is a non-contact, nondestructive analytical technique used to measure surface topography. It is particularly well suited for large area characterization (e.g. full wafers) requiring high vertical accuracy.

Chromatic dispersion profilometers employ a confocal optical configuration in which a broadband white-light beam is focused downward onto a point area of the sample using a lens with intentionally large optical dispersion. The lens causes focal length to vary with wavelength, such that different wavelengths will be in focus at different distances from the detector. Only the narrow band of wavelengths which are in focus at the sample surface are reflected back to the detector, allowing the system to measure surface height at the illuminated point with nm-scale vertical accuracy. Additionally, the large-area sample stage can also translate (move) laterally to allow the measurement lens to analyze surface height at a series of points. This enables 2D or 3D modeling and mapping of surface topography across a full scanned region on the sample.