Optical metrology for integrated circuit fabrication

摘要

A new tool for optical metrology, the Mirau Correlation Microscope (MCM), it introduced. The basic principle of this device is to employ an interference microscope with a temporally and spatially incoherent illumination source, and to use as the detected output the interference signal between the beams reflected from the object and from a reference mirror, respectively. Phase images and cross-sectional images of integrated circuits are obtained. Critical dimension measurements on photoresist linewidths are demonstrated and features with sizes down to 0.4 $mu@m have been measured consistently.