In scatterometry, the intensities of light scattered by an object under a large range of angles is collected from which features of the objects are reconstructed. Scatterometry is an option when the features are too small to be imaged by the wavelength used. Because the reconstruction is ill-posed and very sensitive to noise, it has to be regularized e.g. by a priori knowledge. Scatterometry benefits from polarisation and phase detection.
Small particle detection in roll-to-roll processes and evaluation of the quality of lithography processes. A small particle (Rapidnano) has been developed earlier for small particle detection.