Scatterometry based active control of exposure conditions

Abstract

A system for regulating an exposure condition determining process is provided. The system includes one or more light sources, each light source directing light to one or more gratings exposed on one or more portions of a wafer. Light reflected from the gratings is collected by a measuring system, which processes the collected light. Light passing through the gratings may similarly be collected by the measuring system, which processes the collected light. The collected light is analyzed to determine whether exposure conditions should be adapted prior to exposing a pattern on the wafer. The measuring system provides grating signature data to a processor that determines the acceptability of the exposure condition by comparing determined signatures to desired signatures. The system also includes an exposing system that can be controlled to change exposure conditions. The processor selectively controls the exposing system, via the exposer driving system, to adapt such exposure conditions.

Dependencies are inferred from the claim text.