Measurement of wave-front aberrations in high-resolution opticallithographic systems from printed photoresist patterns

摘要

A new method of measurement of wave-front aberrations innhigh-resolution optical lithographic systems used for semiconductornmanufacturing is proposed. The method is based on the measurement of thenpositional shifts and focus offsets of a set of printed photoresistngrating patterns with different periods and orientations, produced undernnearly fully coherent illumination condition. The proposed experimentalnprocedures are described in detail and various sources of systematic andnrandom errors are discussed. It is estimated that a measurementnprecision of Λ/50 for the wave-front aberrations at selectednpoints on the lens pupil can be achieved with this method