PATTERN RECOGNITION MATCHING FOR BRIGHT FIELD IMAGING OF LOW CONTRAST SEMICONDUCTOR DEVICES

摘要

A pattern recognition matching for bright field imaging of low contrast semiconductor devices is provided to reduce pattern recognition failure and allow for repeatable pattern recognition of the same feature on different bright field systems. A target pattern formed on a substrate positioned on a stage is focused. An image is scanned in a first direction, and a first edge scattering pattern is measured from a first feature of the target pattern, in which the edge scattering pattern is characterized by first and second peaks. A position of an illuminator or beam shaping and relay optics(104) is adjusted along one or more directions perpendicular to a first optical path until the first and second peaks are approximately equal in height.