Kla Corporation

Kla Tencor Corporation

Tom Leviant

Yoel Feler

Barak Bringoltz

Lilach Saltoun

Tal Yaziv

Noga Sella

Ido Adam

Amnon Manassen

Daniel Kandel

Ohad Bachar

Nuriel Amir

Tal Marciano

Evgeni Gurevich

David Gready

Boris Efraty

Yuval Lamhot

Nadav Carmel

Dror Alumot

Ofer Zaharan

Oded Kaminsky

Amir Handelman

Gil Drachuck

Moshe Cooper

Roee Sulimarski

Eltsafon Ashwal

Eltsafon Ashwal-Island

Ze'ev Lindenfeld

Yaron De Leeuw

Zeng Zhao

Yaron Deleeuw

Methods, metrology modules and target designs are provided, which improve the accuracy of metrology measurements. Methods provide flexible handling of multiple measurement recipes and setups and enable relating them to landscape features that indicate their relation to resonance regions and to flat regions. Clustering of recipes, self-consistency tests, common processing of aggregated measurements, noise reduction, cluster analysis, detailed analysis of the landscape and targets with skewed cells are employed separately or in combination to provide cumulative improvements of measurement accuracy.

Accuracy improvements in optical metrology

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

Methods are provided for deriving a partially continuous dependency of metrology metric(s) on recipe parameter(s), analyzing the derived dependency, determining a metrology recipe according to the analysis, and conducting metrology measurement(s) according to the determined recipe. The dependency may be analyzed in form of a landscape such as a sensitivity landscape in which regions of low sensitivity and/or points or contours of low or zero inaccuracy are detected, analytically, numerically or experimentally, and used to configure parameters of measurement, hardware and targets to achieve high measurement accuracy. Process variation is analyzed in terms of its effects on the sensitivity landscape, and these effects are used to characterize the process variation further, to optimize the measurements and make the metrology both more robust to inaccuracy sources and more flexible with respect to different targets on the wafer and available measurement conditions.

Method of analyzing and utilizing landscapes to reduce or eliminate inaccuracy in overlay optical metrology

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Yoqneam Illit, Israel

Tom Leviant