Kla Tencor Corporation

Kla Corporation

Irina Vakshtein

Vladimir Levinski

Daniel Kandel

Zeev Bomzon

Noam Sapiens

Eran Amit

Barak Bringoltz

Guy Cohen

Dana Klein

Guy Ben Dov

Ofir Aharon

Alex Shulman

Vladimir Kamenetsky

The present invention may include acquiring a plurality of overlay metrology measurement signals from a plurality of metrology targets distributed across one or more fields of a wafer of a lot of wafers, determining a plurality of overlay estimates for each of the plurality of overlay metrology measurement signals using a plurality of overlay algorithms, generating a plurality of overlay estimate distributions, and generating a first plurality of quality metrics utilizing the generated plurality of overlay estimate distributions, wherein each quality metric corresponds with one overlay estimate distribution of the generated plurality of overlay estimate distributions, each quality metric a function of a width of a corresponding generated overlay estimate distribution, each quality metric further being a function of asymmetry present in an overlay metrology measurement signal from an associated metrology target.

Method and system for providing a quality metric for improved process control

Methods and calibrations modules are provided, for calibrating a pupil center in scatterometry overlay measurements. The calibration comprises calculating fluctuations from a first statistical figure of merit such as an average of an overlay signal per pixel at the pupil and significantly reducing, for example minimizing, the fluctuations with respect to a second statistical figure of merit thereof, such as a pupil weighted variance of the fluctuations.

Pupil plane calibration for scatterometry overlay measurement

Growing community of inventors

Migdal Haemek, Israel

Irina Vakshtein