Kla Tencor Corporation

Kla Corporation

David Gready

Mark Ghinovker

Nimrod Shuall

Claire Staniunas

Vladimir Levinski

Michael E Adel

Nadav Gutman

Yuri Paskover

Nuriel Amir

Tzahi Grunzweig

Tal Shusterman

Sergey Borodyansky

Tom Leviant

Gil Drachuck

An image-based overlay metrology system is disclosed. The system includes a controller couplable to a metrology sub-system. The controller is configured to receive a set of image signals of a first metrology target disposed on the sample from the metrology sub-system and determine a plurality of harmonic detectivity metric values by calculating a harmonic detectivity metric value for each of the plurality of image signals. The controller is also configured to identify a set of optical measurement conditions of the metrology sub-system based on the plurality of harmonic detectivity metric values, wherein the set of optical measurement conditions define a recipe for optical metrology measurements of the metrology sub-system. The controller then provides the recipe to the metrology sub-system for execution of one or more optical metrology measurements of one or more additional metrology targets.

System and method for application of harmonic detectivity as a quality indicator for imaging-based overlay measurements

Designs for a hybrid overlay target design that includes a target area with both an imaging-based target and a scatterometry-based target are disclosed. The imaging-based overlay target design can include side-by-side grating structure. A scatterometry-based overlay target design at a different location in the target area can include grating-over-grating structure. A method of measuring the hybrid overlay target design and a system with both an imaging optical system and a scatterometry system for measuring the hybrid overlay target design are also disclosed.

Hybrid overlay target design for imaging-based overlay and scatterometry-based overlay

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.

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

Systems and method are provided for analyzing target, process and metrology configuration sensitivities to a wide range of parameters, according to external requirements or inner development and verification needs. Systems comprise the following elements. An input module is arranged to receive parameters relating to targets, target metrology conditions and production processes, to generate target data. A metrology simulation unit is arranged to simulate metrology measurements of targets from the target data and to generate multiple metrics that quantify the simulated target measurements. A sensitivity analysis module is arranged to derive functional dependencies of the metrics on the parameters and to define required uncertainties of the parameters with respect to the derived functional dependencies. Finally, a target optimization module is arranged to rank targets and target metrology conditions with respect to the simulated target measurements.

Target and process sensitivity analysis to requirements

Systems and methods are provided, which calculate overlay misregistration error estimations from analyzed measurements of each ROI (region of interest) in at least one metrology imaging target, and incorporate the calculated overlay misregistration error estimations in a corresponding estimation of overlay misregistration. Disclosed embodiments provide a graduated and weighted analysis of target quality which may be integrated in a continuous manner into the metrology measurement processes, and moreover evaluates target quality in terms of overlay misregistration, which forms a common basis for evaluation of errors from different sources, such as characteristics of production steps, measurement parameters and target characteristics. Such common basis then enables any of combining various error sources to give a single number associated with measurement fidelity, analyzing various errors at wafer, lot and process levels, and/or to trade-off the resulting accuracy for throughput by reducing the number of measurements, in a controlled manner.

Utilizing overlay misregistration error estimations in imaging overlay metrology

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Tel Aviv, Israel

David Gready