Image-based overlay metrology and monitoring using through-focus imaging

A metrology system includes a controller coupled to a detector to image a sample based on the light captured by an objective lens, where an object plane of the detector with respect to the sample is adjustable. The controller may direct the detector to generate reference images of an overlay target...

Full description

Saved in:
Bibliographic Details
Main Authors Gready, David, Staniunas, Claire, Shuall, Nimrod
Format Patent
LanguageEnglish
Published 27.10.2020
Subjects
CALCULATING
COMPUTING
CONTROL OR REGULATING SYSTEMS IN GENERAL
CONTROLLING
COUNTING
FUNCTIONAL ELEMENTS OF SUCH SYSTEMS
IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS ORELEMENTS
PHYSICS
REGULATING
Online AccessGet full text

Cover

More Information
Summary:A metrology system includes a controller coupled to a detector to image a sample based on the light captured by an objective lens, where an object plane of the detector with respect to the sample is adjustable. The controller may direct the detector to generate reference images of an overlay target on the sample at multiple object planes including at least a first reference image at a first sample layer and a second reference image at a second sample layer. The controller may further determine a reference overlay between the first layer and the second layer at the overlay target based on the first reference image and the second reference image. The controller may further select a measurement object plane for single-image overlay determination that corresponds to the reference overlay within a selected tolerance. The controller may further determine overlay for additional overlay targets at the measurement plane.
Bibliography:Application Number: US201816034093