Kla Tencor Corporation

Kla Corporation

Nimrod Shuall

Claire Staniunas

Nadav Gutman

Tzahi Grunzweig

David Gready

Amnon Manassen

Vladimir Levinski

Mark Ghinovker

Eran Amit

Yuri Paskover

Nuriel Amir

Guy Cohen

Amir Widmann

Tal Marciano

Dana Klein

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 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

Systems and method are presented for identifying process variations during manufacture of products such as semiconductor wafers. At a predetermined stage during manufacture of a first products, images of an area of the first product are obtained using different values of at least one imaging parameter. The images are then analyzed to generate a first contrast signature for said first product indicating variations of contrast with said at least one imaging parameter. At the same predetermined stage during manufacture of a second product, images of an area of said second product are obtained corresponding to said area of said first product using different values of said at least one imaging parameter. The images are analyzed to generate a second contrast signature for said second product indicating variations of contrast with said at least one imaging parameter. The first and second contrast signatures are compared to identify whether a variation in process occurred between manufacture of said first and second products.

Identifying process variations during product manufacture

Aspects of the present disclosure describe systems and methods for calibrating a metrology tool by using proportionality factors. The proportionality factors may be obtained by measuring a substrate under different measurement conditions. Then calculating the measured metrology value and one or more quality merits. From this information, proportionality factors may be determined. Thereafter the proportionality factors may be used to quantify the inaccuracy in a metrology measurement. The proportionality factors may also be used to determine an optimize measurement recipe. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Method for estimating and correcting misregistration target inaccuracy

Growing community of inventors

Beaverton, OR, United States of America

Nimrod Shuall