Methods and systems for measurement of large dimension structures fabricated using semiconductor processing techniques

Abstract

Methods and systems for performing accurate and robust scatterometry based measurements of relatively large dimension structures fabricated using semiconductor fabrication processes are presented herein. In some examples, relatively large dimension structures include spiral-shaped features that are not periodic. In one aspect, one or more relatively large dimension device structures are fabricated on a specimen along with one or more proxy metrology targets. Each of the one or more proxy metrology targets are spatially periodic and include an array of nominally identical curved segments characterized by a radius of curvature. The radius of curvature associated with each of the plurality of proxy metrology targets corresponds to the radius of curvature of each of the plurality of turnings of a spiral-shaped device structure. In preferred embodiments, the film stack and line / space ratio associated with each of the proxy metrology targets is the same as the device structures.

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