A metrology device produces broadband illumination, e.g., an illumination line, that is incident on a substrate at an oblique angle of incidence and which is scanned across the substrate. A first detector collects a darkfield image, while a second detector collects the spectrally reflected light. The...http://www.google.de/patents/US7433034?utm_source=gb-gplus-sharePatent US7433034 - Darkfield defect inspection with spectral contents
