Kla Corporation

Kla Tencor Corporation

Other

Stefan Eyring

Nadav Gutman

Frank Laske

Ulrich Pohlmann

Inna Steely-Tarshish

Mark Ghinovker

Raviv Yohanan

Eitan Hajaj

Ira Naot

Yoel Feler

Henning Stoschus

Christopher Sears

Chris Steely

Oliver Ache

Eran Amit

Hari Pathangi

Yoel Feier

Zhijin Chen

Thomas Heidrich

A wafer metrology tool, such as a scanning electron microscope, can generate an image of a structure on a wafer. A simulated image of the structure also is determined from a design of the wafer. A contour of the structure in the image and a contour of the structure in the simulated image are determined. These contours are compared.

Image modeling-assisted contour extraction

A metrology system may receive design data including a layout of fabricated instances of a structure on a sample. The system may further receive detection signals from the metrology tool associated within a field of view including multiple of the fabricated instances of the structure. The system may further generate design-assisted composite data for the structure by combining detection signals from one or more common features of the structure associated with the fabricated instances of the structure within the field of view using the design data. The system may further generate one or more metrology measurements of the structure based on the design-assisted composite data.

Design-assisted large field of view metrology

Electron beam overlay targets and method of performing overlay measurements on a target using a semiconductor metrology tool are provided. One target includes a plurality of electron beam overlay elements and a plurality of two-dimensional elements that provide at least one two-dimensional imaging. The plurality of two dimensional elements are an array of evenly-spaced polygonal gratings across at least three rows and at least three columns. Another target includes a plurality of electron beam overlay elements and a plurality of AIMid elements. Each of the electron beam overlay elements includes at least two gratings that are overlaid at a perpendicular orientation to each other. The plurality of AIMid elements includes at least two gratings that are overlaid at a perpendicular orientation to each other.

Overlay mark design for electron beam overlay

Embodiments may include methods, systems, and apparatuses for correcting a response function of an electron beam tool. The correcting may include modulating an electron beam parameter having a frequency; emitting an electron beam based on the electron beam parameter towards a specimen, thereby scattering electrons, wherein the electron beam is described by a source wave function having a source phase and a landing angle; detecting a portion of the scattered electrons at an electron detector, thereby yielding electron data including an electron wave function having an electron phase and an electron landing angle; determining, using a processor, a phase delay between the source phase and the electron phase, thereby yielding a latency; and correcting, using the processor, the response function of the electron beam tool using the latency and a difference between the source wave function and the electron wave function.

Detection and correction of system responses in real-time

The present disclosure provides a target and a method of performing overlay measurements on a target. The target includes an array of cells comprising a first cell, a second cell, a third cell, and a fourth cell. Each cell includes a periodic structure with a pitch. The periodic structure includes a first section and a second section, separated by a first gap. The target further includes an electron beam overlay target, such that electron beam overlay measurements, advanced imaging metrology, and/or scatterometry measurements can be performed on the target.

Combined electron beam overlay and scatterometry overlay targets include first and second periodic structures with gratings. Gratings in the second periodic structure can be positioned under the gratings of the first periodic structure or can be positioned between the gratings of the first periodic structure. These overlay targets can be used in semiconductor manufacturing.

Overlay design for electron beam and scatterometry overlay measurements

A detection and correction method for an electron beam system are provided. The method includes emitting an electron beam towards a specimen; modulating a beam current of the electron beam to obtain a beam signal. The method further includes detecting, using an electron detector, secondary and/or backscattered electrons emitted by the specimen to obtain electron data, wherein the electron data defines a detection signal. The method further includes determining, using a processor, a phase shift between the beam signal and the detection signal. The method further includes filtering, using the processor, the detection signal based on the phase shift.

A field-of-view at a first modeled target location of a first target disposed on a specimen can be configured, which can include moving the stage relative to the detector. The first modeled target location is determined by summing a first design target location and a navigational error provided by an online model. A first image of the field-of-view is grabbed using the detector. The field-of-view at a second modeled target location of a second target disposed on the specimen is configured. Concurrent with configuring the field-of-view at the second modeled target location, using a processor, the position of a first actual target location is determined using the first image. The online model is updated with a difference between the first design target location and the first actual target location.

Online navigational drift correction for metrology measurements

A metrology system may include a characterization tool configured to generate metrology data for a sample based on the interaction of an illumination beam with the sample, and may also include one or more adjustable measurement parameters to control the generation of metrology data. The metrology system may include one or more processors that may receive design data associated with a plurality of regions of interest for measurement, select individualized measurement parameters of the characterization tool for the plurality of regions of interest, and direct the characterization tool to characterize the plurality of regions of interest based on the individualized measurement parameters.

Performance optimized scanning sequence for eBeam metrology and inspection

An overlay metrology system includes a particle-beam metrology tool to scan a particle beam across an overlay target on a sample including a first-layer target element and a second-layer target element. The overlay metrology system may further include a controller to receive a scan signal from the particle-beam metrology tool, determine symmetry measurements for the scan signal with respect to symmetry metrics, and generate an overlay measurement between the first layer and the second layer based on the symmetry measurements in which an asymmetry of the scan signal is indicative of a misalignment of the second-layer target element with respect to the first-layer target element and a value of the overlay measurement is based on the symmetry measurements.

Overlay measurements of overlapping target structures based on symmetry of scanning electron beam signals

An overlay metrology system may measure a first-layer pattern placement distance between a pattern of device features and a pattern of reference features on a first layer of an overlay target on a sample. The system may further measure, subsequent to fabricating a second layer including at least the pattern of device features and the pattern of reference features, a second-layer pattern placement distance between the pattern of device features and the pattern of reference features on the second layer. The system may further measure a reference overlay based on relative positions of the pattern of reference features on the first layer and the second layer. The system may further determine a device-relevant overlay for the pattern of device-scale features by adjusting the reference overlay with a difference between the first-layer pattern placement distance and the second-layer pattern placement distance.

Systems and methods for device-correlated overlay metrology

An apparatus and a method are disclosed for the measurement of pattern placement and/or edge placement and/or size of a pattern on a surface of a substrate for the semiconductor industry. At least one source for detection and at least one assigned detector are used to measure the positions of a pattern on a substrate. With a movable stage the substrate is moved while detection takes place. A displacement measurement system determines the position of the movable stage during the movement. A computer is used for correlating detected signals of the at least one detector along the derived trace line with the actual positions of the stage during the movement of the stage.

Apparatus and method for the measurement of pattern placement and size of pattern and computer program therefor

A method for correcting optical errors occurring in coordinates of positions of a plurality of targets measured via an imaging system comprising a field of view. The plurality of targets includes a first array of targets and a second array of targets overlapping the first array of targets, and a portion of the plurality of targets are outside of the field of view. The method broadly includes the following steps: a) placing the first array of targets in the field of view of the imaging system; b) measuring coordinates of each target within the first array of targets repeatedly via the imaging system; c) placing the second array of targets in the field of view of the imaging system; d) measuring coordinates of each target within the second array of targets repeatedly via the imaging system; e) determining an alignment function from the measurement results of step b, step d, or steps b and d, the alignment function being a function of coordinates of the field of view of the imaging system and giving an additive correction for optical errors of the coordinates of positions of the plurality of targets measured by the imaging system; f) correcting the coordinates of the positions of the plurality of targets measured by the imaging system by adding the respective value of the alignment function at the field-of-view coordinates at which the coordinates of the position of the respective target were measured; and, g) obtaining a final result for the position of each target of the plurality of targets by averaging over the corrected coordinates found in step f for the respective target at each relative position of the plurality of targets and field of view of the imaging system.

Method for correcting position measurements for optical errors and method for determining mask writer errors

A method is disclosed for correcting errors introduced by optical distortions or aberrations in the measured values of coordinates of targets of an array of targets, like for example structures on a wafer or a photolithography mask. The array of targets is placed into a field of view of an imaging system via which the coordinates are to be measured. The array of targets is placed at different relative positions with respect to the field of view, and for each relative position the coordinates of the targets relative to the array of targets are determined by measurements. From the results of these measurements an alignment function, giving a correction for optical errors as a function of the position in the field of view, is derived. The measured coordinates are corrected by the alignment function. The corrected coordinates can be used to identify registration errors of a mask writer.

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Weilburg, Germany

Stefan Eyring