Kla Tencor Corporation

Kla Corporation

Noam Sapiens

Daniel Kandel

Andrei V Shchegrov

Stilian Pandev

Kevin A Peterlinz

Vladimir Levinski

Joel L Seligson

Amnon Manassen

Shankar Krishnan

Yoel Feler

Barak Bringoltz

Alexander Svizher

Alexander Buettner

Jiyou Fu

Kerstin Purrucker

Michael Friedmann

Thaddeus Gerard Dziura

Daria Negri

Ohad Bachar

Meir Aloni

Barry Blasenheim

Guy Ben Dov

Hadar Shalmoni

John Josef Hench

Alexander Kuznetsov

David Y Wang

Guy Cohen

Gregory Brady

Boris Golovanevsky

Pablo Rovira

Moshe Baruch

Paykin Irina

Efraim Rotem

Andrew V Hill

Eran Amit

Dana Klein

Andy Hill

Ofer Zaharan

Irina Vakshtein

Eliav Benisty

Alex Shulman

Irina Paykin

Vladimir Kamenetsky

The present invention may include acquiring a plurality of overlay metrology measurement signals from a plurality of metrology targets distributed across one or more fields of a wafer of a lot of wafers, determining a plurality of overlay estimates for each of the plurality of overlay metrology measurement signals using a plurality of overlay algorithms, generating a plurality of overlay estimate distributions, and generating a first plurality of quality metrics utilizing the generated plurality of overlay estimate distributions, wherein each quality metric corresponds with one overlay estimate distribution of the generated plurality of overlay estimate distributions, each quality metric a function of a width of a corresponding generated overlay estimate distribution, each quality metric further being a function of asymmetry present in an overlay metrology measurement signal from an associated metrology target.

Method and system for providing a quality metric for improved process control

A collection system of a semiconductor metrology tool includes a chuck to support a target from which an optical beam is reflected and a spectrometer to receive the reflected optical beam. The collection system also includes a plurality of aperture masks arranged in a rotatable sequence about an axis parallel to an optical axis. Each aperture mask of the plurality of aperture masks is rotatable into and out of the reflected optical beam between the chuck and the spectrometer to selectively mask the reflected optical beam.

Variable aperture mask

Methods and systems for performing spectroscopic measurements of semiconductor structures including ultraviolet, visible, and infrared wavelengths greater than two micrometers are presented herein. A spectroscopic measurement system includes a combined illumination source including a first illumination source that generates ultraviolet, visible, and near infrared wavelengths (wavelengths less than two micrometers) and a second illumination source that generates mid infrared and long infrared wavelengths (wavelengths of two micrometers and greater). Furthermore, the spectroscopic measurement system includes one or more measurement channels spanning the range of illumination wavelengths employed to perform measurements of semiconductor structures. In some embodiments, the one or more measurement channels simultaneously measure the sample throughout the wavelength range. In some other embodiments, the one or more measurement channels sequentially measure the sample throughout the wavelength range.

Methods and systems for measurement of thick films and high aspect ratio structures

In some embodiments, a collection system of a semiconductor metrology tool includes a chuck to support a target from which an optical beam is reflected and an aperture mask to provide an adjustable aperture for the reflected optical beam. The aperture mask includes a plurality of opaque plates with adjustable positions. The collection system also includes a spectrometer to receive the reflected optical beam. The aperture mask is situated between the chuck and the spectrometer along the optical axis.

Methods and systems are presented to reduce the illumination spot size projected onto a measurement target and associated spillover onto area surrounding a measurement target. In one aspect, a spatial light modulator (SLM) is located in the illumination path between the illumination light source and the measurement sample. The SLM is configured to modulate amplitude, phase, or both, across the path of the illumination light to reduce wavefront errors. In some embodiments, the desired state of the SLM is based on wavefront measurements performed in an optical path of the metrology system. In another aspect, an illumination aperture having an image plane tilted at an oblique angle with respect to a beam of illumination light is employed to overcome defocusing effects in metrology systems that employ oblique illumination of the measurement sample. In some embodiments, the illumination aperture, objective lens, and specimen are aligned to satisfy the Scheimpflug condition.

Optical metrology with small illumination spot size

Methods and systems for evaluating the performance of multiple patterning processes are presented. Patterned structures are measured and one or more parameter values characterizing geometric errors induced by the multiple patterning process are determined. In some examples, a single patterned target and a multiple patterned target are measured, the collected data fit to a combined measurement model, and the value of a structural parameter indicative of a geometric error induced by the multiple patterning process is determined based on the fit. In some other examples, light having a diffraction order different from zero is collected and analyzed to determine the value of a structural parameter that is indicative of a geometric error induced by a multiple patterning process. In some embodiments, a single diffraction order different from zero is collected. In some examples, a metrology target is designed to enhance light diffracted at an order different from zero.

Measurement of multiple patterning parameters

Metrology methods, systems and targets are provided, which implement a side by side paradigm. Adjacent cells with periodic structures are used to extract the overlay error, e.g., by introducing controllable phase shifts or image shifts which enable algorithmic computation of the overlay. The periodic structures are designed to exhibit a rotational symmetry to support the computation and reduce errors.

Symmetric target design in scatterometry overlay metrology

An overlay metrology system includes an overlay metrology tool configurable to generate overlay signals with a plurality of recipes and further directs an illumination beam to an overlay target and collects radiation emanating from the overlay target in response to the at least a portion of the illumination beam to generate the overlay signal with the particular recipe. The overlay metrology system further acquires two or more overlay signals for a first overlay target using two or more unique recipes, subsequently acquires two or more overlay signals for a second overlay target using the two or more unique recipes, determines candidate overlays for the first and second overlay targets based on the two or more overlay signals for each target, and determines output overlays for the first and second overlay targets based on the two or more candidate overlays for each target.

Overlay metrology using multiple parameter configurations

Methods and systems for measuring a specimen while actively stabilizing an optical measurement beam subject to changes in polarization by a rotating polarizer element are described herein. Movement of a focused measurement beam spot induced by a rotating polarizer element is compensated by actively controlling the position of an optical element in the beam path based on measurements of the focused measurement beam spot. Both feedback and feedforward control schemes may be employed to reduce beam position error. In one aspect, a measurement system includes a rotating optical polarizer, a beam position sensor, and an active beam compensating element in the illumination beam path, the collection beam path, or both. Beam position errors are detected by the beam position sensor, and control commands are communicated to the active beam compensating element to reduce the measured beam position errors.

Systems and methods for metrology beam stabilization

Contrast enhancement in a metrology tool may include generating a beam of illumination, directing a portion of the generated beam onto a surface of a spatial light modulator (SLM), directing at least a portion of the generated beam incident on the surface of the SLM through an aperture of an aperture stop and onto one or more target structures of one or more samples, and generating a selected illumination pupil function of the illumination transmitted through the aperture utilizing the SLM in order to establish a contrast level of one or more field images of the one or more target structures above a selected contrast threshold, and performing one or more metrology measurements on the one or more target structures utilizing the selected illumination pupil function.

Structured illumination for contrast enhancement in overlay metrology

Metrology systems and methods are provided herein, which comprise an optical element that is positioned between an objective lens of the system and a target. The optical element is arranged to enhance evanescent modes of radiation reflected by the target. Various configurations are disclosed: the optical element may comprise a solid immersion lens, a combination of Moir&#xe9;-elements and solid immersion optics, dielectric-metal-dielectric stacks of different designs, and resonating elements to amplify the evanescent modes of illuminating radiation. The metrology systems and methods are configurable to various metrology types, including imaging and scatterometry methods.

Near field metrology

A spectroscopic beam profile metrology system simultaneously detects measurement signals over a large wavelength range and a large range of angles of incidence (AOI). In one aspect, a multiple wavelength illumination beam is reshaped to a narrow line shaped beam of light before projection onto a specimen by a high numerical aperture objective. After interaction with the specimen, the collected light is passes through a wavelength dispersive element that projects the range of AOIs along one direction and wavelength components along another direction of a two-dimensional detector. Thus, the measurement signals detected at each pixel of the detector each represent a scatterometry signal for a particular AOI and a particular wavelength. In another aspect, a hyperspectral detector is employed to simultaneously detect measurement signals over a large wavelength range, range of AOIs, and range of azimuth angles.

Method and system for spectroscopic beam profile metrology including a detection of collected light according to wavelength along a third dimension of a hyperspectral detector

In one embodiment, apparatus and methods for determining a parameter of a target are disclosed. A target having an imaging structure and a scatterometry structure is provided. An image of the imaging structure is obtained with an imaging channel of a metrology tool. A scatterometry signal is also obtained from the scatterometry structure with a scatterometry channel of the metrology tool. At least one parameter, such as overlay error, of the target is determined based on both the image and the scatterometry signal.

Apparatus, techniques, and target designs for measuring semiconductor parameters

A spectroscopic beam profile metrology system simultaneously detects measurement signals over a large wavelength range and a large range of angles of incidence (AOI). In one aspect, a multiple wavelength illumination beam is reshaped to a narrow line shaped beam of light that is projected onto an overlay metrology target such that the direction of the line shaped beam is aligned with the direction of extent of a grating structure of the overlay metrology target. Collected light is dispersed across a detector according to AOI in one direction and according to wavelength in another direction. The measured signal at each detector pixel is associated with a particular AOI and wavelength. The collected light includes first order diffracted light, zero order diffracted light, or a combination thereof. In some embodiments, first order diffracted light and zero order diffracted light are detected over separate areas of the detector.

Spectroscopic beam profile overlay metrology

Growing community of inventors

Cupertino, CA, United States of America

Noam Sapiens