Nanometrics employs white light microscopy as a method to obtain quantitative noncontact measurements in front-end and back-end of line semiconductor, LED, HDD, and MEMs manufacturing applications. Incorporated in the SPARK system, the technology utilizes a white light beam which passes through a filter and then a microscope objective lens to the surface of the wafer. Illumination conditions are optimized for the various measurements performed — defect location, critical dimension, or layer-to-layer overlay. Depending on the analysis, darkfield (illumination from the sides) or brightfield (illumination from the top) are used. The resultant image is measured using a wide array of algorithms, giving sub-nm sensitivity, even with visible light.