Kla Tencor Corporation

Kla Corporation

Kla-tencor Technologies Corporation

Xerox Corporation

Kla Corporation Ca

Andrew V Hill

Amnon Manassen

Ohad Bachar

Vladimir Levinski

Daniel Kandel

Avi Abramov

Daria Negri

Yuri Paskover

Ilan Sela

Andrei V Shchegrov

Alexander Svizher

Yonatan Vaknin

Mark Ghinovker

Barak Bringoltz

Joel L Seligson

Gilad Laredo

Moshe Markowitz

Gregory Brady

Barry Loevsky

Yossi Simon

Efraim Rotem

Yung-Ho Alex Chuang

Yoram Uziel

Nadav Gutman

Lawrence D Rotter

Yuval Lubashevsky

Dmitry Gorelik

Mehdi Vaez-Iravani

Guoheng Zhao

Ilya Bezel

Anatoly Shchemelinin

Zeev Bomzon

Roie Volkovich

David W Shortt

Eran Amit

Nuriel Amir

Derrick A Shaughnessy

Anna Golotsvan

Tzahi Grunzweig

Avner Safrani

Muzammil A Arain

Nireekshan K Reddy

Nir BenDavid

Nachshon Rothman

Yaron Ish-Shalom

Dror Yaacov

Anatoly A Vasiliev

James Andrew Allen

Oleg Shulepov

Maxim Khokhlov

Oleg Tsibulevsky

Donald R Titterington

David Lyell Knierim

Trevor James Snyder

Bo Wu

David Lee Brown

Jule W Thomas, Jr

Stanley E Stokowski

Hwan J Jeong

Yoel Feler

Noam Sapiens

David Y Wang

Robert M Danen

Yuval Ben-Dov

Randall Ray Bridgeman

Mark Shi Wang

Jonathan M Madsen

Johannes D De Veer

Itay Gdor

Hans J Hansen

Chris Maher

Johan De Greeve

Karel Van Gils

Harish P Hiriyannaiah

Steven V Korol

Amit Shaked

Younus Vora

Anatoly Vasiliev

Jennifer Misae Miyamoto

Asaf Granot

Yingjian Wang

Amy R Bartlett

Maarten Van Der Burgt

Avijit K Ray-Chaudhuri

Zheng-wu Li

Courosh Mehanian

Eugene Maslovsky

Dor Perry

Verlyn Fischer

Ping Ding

Kurt Zimmermann

Valery Garmider

Alexander Novikov

Izhar Agam

A metrology system may include a controller to receive two or more images of the overlay target from one or more detectors of an optical sub-system, the overlay target including first and second periodic features generated with different measurement conditions, each measurement condition associated with at least one of a sample focal distance or a configuration of diffraction orders of the illumination by the overlay target that contributes to the associated image. The controller may further calculate an amplitude asymmetry associated of opposing diffraction orders of the illumination by the overlay target based on the two or more images and one or more quality metrics associated with the overlay target based on the amplitude asymmetry.

Amplitude asymmetry measurements in overlay metrology

An overlay metrology system may include an illumination an illumination source to generate an illumination beam, one or more illumination optics to direct the illumination beam to an overlay target on a sample as the sample is scanned relative to the illumination beam along a scan direction, the target including one or more cells having Moiré structures. The system may also include two photodetectors at locations of a pupil plane associated with Moiré or overlapping diffraction orders from the Moiré structures. The system may then generate overlay measurements based on time-varying interference signals captured by the detector as the sample is scanned.

Scanning scatterometry overlay metrology

A multi-column metrology tool may include two or more measurement columns distributed along a column direction, where the two or more measurement columns simultaneously probe two or more measurement regions on a sample including metrology targets. A measurement column may include an illumination sub-system to direct illumination to the sample, a collection sub-system including a collection lens to collect measurement signals from the sample and direct it to one or more detectors, and a column-positioning sub-system to adjust a position of the collection lens. A measurement region of a measurement column may be defined by a field of view of the collection lens and a range of the positioning system in the lateral plane. The tool may further include a sample-positioning sub-system to scan the sample along a scan path different than the column direction to position metrology targets within the measurement regions of the measurement columns for measurements.

Massive overlay metrology sampling with multiple measurement columns

An oscillating secondary stage in a metrology system. The metrology system includes a primary stage configured for long movement to transport a wafer from a one location to another. A secondary stage coupled to the primary stage holds the wafer is configured to oscillate between the first direction and a second direction. The oscillation of the second stage allows for capturing an image frame of the wafer at a target location while the primary stage is moving.

Oscillating secondary stage for frame-mode overlay metrology

An overlay metrology system may include illumination optics to split illumination from an illumination source into primary and secondary illumination and direct the primary illumination to a sample including an overlay target with gratings in two or more layers and an objective lens to collect positive and negative diffraction from the constituent gratings. The system may further include collection optics to overlap the auxiliary illumination with at least some of the collected diffraction lobes to generate time-varying interference signals. The system may further include a controller to generate overlay measurements based on the time-varying interference signals.

Scanning overlay metrology with high signal to noise ratio

An overlay metrology system may include an objective lens, illumination optics to illuminate an overlay target including a first grating with a first pitch on a first sample layer and a second grating with a second pitch on a second sample layer, where the first and second sample layers are separated by a layer separation distance greater than a depth of field of the objective lens. The system may further include collection optics with a radially-varying defocus distribution to compensate for the layer separation distance such that the first and second gratings are simultaneously in focus on the detector.

Single grab overlay measurement of tall targets

An overlay metrology system may include illumination sources configured to generate one or more pairs of mutually coherent illumination beams and illumination optics to direct the pairs of illumination beams to an overlay target at common altitude incidence angles and symmetrically opposed azimuthal incidence angles, where the overlay target includes two or more grating structures distributed along one or more measurement directions. The system may further include imaging optics to image the overlay target onto detectors when implementing the metrology recipe, where an image of a particular one of the two or more grating structures is generated exclusively with a single non-zero diffraction order of light from each of the illumination beams within the particular one of the pairs of illumination beams. The system may further include a controller to determine overlay measurements based on images of the overlay target.

Imaging overlay with mutually coherent oblique illumination

A method includes generating a sequence of images of a semiconductor wafer from first and second detectors. The first detector images the wafer with first imaging parameters and the second detector images the wafer with second imaging parameters. The first or second imaging parameters are varied across the sequence of images to provide variation at sites across the wafer. The method includes providing a metric indicative of center-of-symmetry variations of first and second target features as a function of the varied imaging parameters based on the sequence of images. The method includes identifying a landscape of values of the varied image parameters for which the metric are below a predefined limit. The method includes generating a recipe for metrology measurements in which the varied imaging parameters are set to values within the landscape. The method includes generating metrology measurements from a production wafer based on the recipe.

Enhancing performance of overlay metrology

A metrology system may include a metrology tool to selectively perform metrology measurements in a static mode in which one or more metrology targets on a sample are stationary during a measurement or a scanning mode in which one or more metrology targets are in motion during a measurement, and a controller communicatively coupled to the translation stage and at least one of the one or more detectors. The controller may receive locations of metrology targets on the sample to be inspected, designate the metrology targets for inspection with the static mode or the scanning mode, direct the metrology tool to perform metrology measurements on the metrology targets in the static mode or the scanning mode based on the designation, and generate metrology data for the sample based on the metrology measurements on the metrology targets.

Sensitive optical metrology in scanning and static modes

A metrology system may include an imaging sub-system including one or more lenses and a detector to image a sample, where the sample includes metrology target elements on two or more sample layers. The metrology system may further include a controller to determine layer-specific imaging configurations of the imaging sub-system to image the metrology target elements on the two or more sample layers within a selected image quality tolerance, where each layer-specific imaging configuration includes a selected configuration of one or more components of the imaging sub-system. The controller may further receive, from the imaging sub-system, one or more images of the metrology target elements on the two or more sample layers generated using the layer-specific imaging configurations. The controller may further provide a metrology measurement based on the one or more images of the metrology target elements on the two or more sample layers.

Systems and methods for metrology with layer-specific illumination spectra

An overlay metrology system may scan a sample including inverted Moir&#xe9; structure pairs along a scan direction, include an illumination sub-system to illuminate first and second Moir&#xe9; structures of one of an inverted Moir&#xe9; structure pair with common mutually coherent illumination beam distributions, and include an objective lens to capture at least +/&#x2212;1 diffraction orders from sample, where a first pupil plane includes overlapping distributions of the collected light with an interference pattern associated with relative wavefront tilt. The system may also include a diffractive element in the first pupil plane, where one diffraction order associated with the first Moir&#xe9; structure and one diffraction order associated with the second Moir&#xe9; structure overlap at a common overlap region in a field plane, and a collection field stop located in the field plane to pass light in the common overlap region and block remaining light and remove the relative wavefront tilt.

Moir&#xe9; scatterometry overlay

An optical metrology system may include an overlay metrology tool for characterizing an overlay target on a sample, where the overlay target includes first-direction periodic features in a first set of layers of the sample, and second-direction periodic features in a second set of layers of the sample. The overlay metrology tool may simultaneously illuminate the overlay target with first illumination beams and second illumination beams and may further generate images of the overlay target based on diffraction of the first illumination beams and the second illumination beams by the overlay target, where diffraction orders of the first illumination beams contribute to resolved image formation of only the first-direction periodic features, and where diffraction orders of the second illumination beams contribute to resolved image formation of only the second-direction periodic features. The system may further generate overlay measurements along the first and second measurement directions based on the images.

Multi-directional overlay metrology using multiple illumination parameters and isolated imaging

A method for imaging overlay targets on a wafer includes (1) using a sensor to acquire images of overlay targets on a wafer while the wafer is in motion and (2) accelerating and decelerating the wafer to move the overlay targets into alignment with the sensor between acquiring images of the overlay targets. Accelerating/decelerating the wafer may include: (1) accelerating the wafer at a maximum acceleration and then decelerating the wafer at a maximum deceleration, (2) accelerating/decelerating the wafer in a triangular waveform pattern, (3) accelerating/decelerating the wafer in a sinusoidal pattern, or (4) accelerating/decelerating the wafer in a near-sinusoidal pattern (created by combining a pure sinusoidal profile with one or more harmonic profiles). A system is also provided for implementing the above method(s).

Modulation of scanning velocity during overlay metrology

A tunable filter may include an input focusing optic, an output focusing optic, a linearly-varying filter located at a back focal plane of the input focusing optic and a front focal plane of the output focusing optic, an input angular scanning component located at a front focal plane of the input focusing optic configured to receive an input beam, and an output angular scanning component located at a back focal plane of the output focusing optic. The input focusing optic may receive the input beam from the input angular scanning component and direct the input beam to the linearly-varying filter, where a position of the input beam on the linearly-varying filter is selectable based on an angle of the input angular scanning component. The output focusing optic may receive a filtered beam from the linearly-varying filter and direct the filtered beam to the output angular scanning component.

Broadband illumination tuning

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Berkeley, CA, United States of America

Andrew V Hill