Kla Corporation

Itay Gdor

Yuval Lubashevsky

Vladimir Levinski

Daria Negri

Yoram Uziel

Yuri Paskover

Eitan Hajaj

Alexander Volfman

Yevgeniy Men

Amnon Manassen

Andrew V Hill

Nadav Gutman

Yonatan Vaknin

Alon Alexander Volfman

Yuval Lubashevksy

Elad Farchi

Yaniv Weiss

Iftach Galon

Nireekshan Reddy

A method for overlay metrology may include generating broadband illumination beams and directing the broadband illumination beams to an overlay target on a sample, where the overlay target may include cells having periodic features formed as overlapping grating structures. The method may include generating diffracted light using the periodic features of the overlay target, where the periodic features may act as a diffraction grating to generate diffracted light by separating the broadband illumination beam into a plurality of wavelengths. The method may include generating pupil images of cells of the overlay target, where a distribution of light in the pupil plane may include first-order diffraction lobes, where spectra of the first-order diffraction lobes may be spatially dispersed in the pupil plane. The method may include generating an overlay measurement based on portions of the pupil images corresponding to selected wavelengths of the spectra of the first-order diffraction lobes.

Single grab pupil landscape via broadband illumination

A system includes an illumination source configured to generate an illumination beam, and a collection sub-system that includes an objective lens, one or more detectors located at a collection pupil plane, a light modulator, and a controller. The light modulator is configured to direct one or more selected portions of measurement light to the one or more detectors. The controller includes one or more processors configured to execute program instructions causing the one or more processors to execute a metrology recipe by: receiving detection signals from the one or more detectors, wherein the detection signals are associated with the one or more selected portions of the measurement light directed to the one or more detectors; and generating an overlay measurement associated with at least two layers of a sample based on the detection signals.

System and method for isolation of specific fourier pupil frequency 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

An overlay metrology system is disclosed. The overlay metrology system may include a controller with one or more processors. The processors may be configured to execute program instructions causing the processors to receive pupil images of collected light from an overlay target and receive a known phase distribution to be introduced to an illumination beam directed at the overlay target. The processors may model an intensity function relating the pupil images, the known phase distribution, and one or more decentered shift parameters of structures of the overlay target. The processors may fit the pupil images to the intensity function depending on the known phase distribution and the decentered shift parameters. The processors may generate an overlay measurement based on the fit.

System and method for overlay metrology using a phase mask

Metrology is performed on a semiconductor wafer using a system with an apodizer. A spot is formed on the semiconductor wafer with a diameter from 2 nm to 5 nm. The associated beam of light has a wavelength from 400 nm to 800 nm. Small target measurement can be performed at a range of optical wavelengths.

Annular apodizer for small target overlay measurement

A method for semiconductor metrology includes depositing first and second overlying film layers on a semiconductor substrate and patterning the layers to define an overlay target. The target includes a first grating pattern in the first layer, including at least a first linear grating oriented in a first direction and at least a second linear grating oriented in a second direction perpendicular to the first direction, and a second grating pattern in the second layer, including at least a third linear grating identical to the first linear grating and a fourth linear grating identical to the second linear grating. The second grating pattern has a nominal offset relative to the first grating pattern by first and second displacements in the first and second directions, respectively. A scatterometric image of the substrate is captured and processed to estimate an overlay error between the patterning of the first and second layers.

Targets for diffraction-based overlay error metrology

An overlay metrology system may include an illumination source and illumination optics to illuminate an overlay target on a sample with illumination from the illumination source as the sample is in motion with respect to the illumination from the illumination source in accordance with a measurement recipe. The overlay target may include one or more cells, where a single cell is suitable for measurement along a particular direction. Such a cell may include two or more gratings with different pitches. Further, the system may include two or more photodetectors, each configured to capture three diffraction lobes from the two or more grating structures. The system may further include a controller to determine an overlay measurement associated with each cell of the overlay target.

Scanning overlay metrology using overlay targets having multiple spatial frequencies

A target for use in the measurement of misregistration between layers formed on a wafer in the manufacture of semiconductor devices, the target including a first pair of periodic structures (FPPS) and a second pair of periodic structures (SPPS), each of the FPPS and the SPPS including a first edge, a second edge, a plurality of first periodic structures formed in a first area as part of a first layer and having a first pitch along a first pitch axis, the first pitch axis not being parallel to either of the first edge or second edge, and a plurality of second periodic structures formed in a second area as part of a second layer and having the first pitch along a second pitch axis, the second pitch axis being generally parallel to the first pitch axis.

Non-orthogonal target and method for using the same in measuring misregistration of semiconductor devices

A metrology target is disclosed, in accordance with one or more embodiments of the present disclosure. The metrology target includes a first set of pattern elements having a first pitch, where the first set of pattern elements includes segmented pattern elements. The metrology target includes a second set of pattern elements having a second pitch, where the second set of pattern elements includes segmented pattern elements. The metrology target includes a third set of pattern elements having a third pitch, where the third set of pattern elements includes segmented pattern elements.

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Halevi, Israel

Itay Gdor