Abstract: Methods and systems for detecting defects on a wafer are provided. One method includes creating a searchable database for a design for a wafer, which includes assigning values to different portions of the design based on patterns in the different portions of the design and storing the assigned values in the searchable database. Different portions of the design having substantially the same patterns are assigned the same values in the searchable database. The searchable database is configured such that searching of the database can be synchronized with generation of output for the wafer by one or more detectors of a wafer inspection system. Therefore, as the wafer is being scanned, design information for the output can be determined as fast as the output is generated, which enables multiple, desirable design based inspection capabilities.

Abstract: Methods and systems for detecting defects on a wafer are provided. One method includes determining characteristics of care areas for a wafer based on wafer patterns. Determining the characteristics includes determining locations of care areas, identifying at least one pattern of interest (POI) in the wafer patterns for each of the care areas, allowing any of the care areas to have a free-form shape, allowing the care areas to be larger than frame images and selecting two or more POIs for at least one of the care areas. The method also includes searching for POIs in images generated for the wafer using an inspection system. In addition, the method includes detecting defects on the wafer by determining positions of the care areas in the images and applying one or more defect detection methods to the images based on the positions of the care areas in the images.

Abstract: Systems and methods for design-based inspection using repeating structures are provided.

Abstract: Systems and methods for determining a position of output of an inspection system in design data space are provided. One method includes merging more than one feature in design data for a wafer into a single feature that has a periphery that encompasses all of the features that are merged. The method also includes storing information for the single feature without the design data for the features that are merged. The information includes a position of the single feature in design data space. The method further includes aligning output of an inspection system for the wafer to the information for the single feature such that positions of the output in the design data space can be determined based on the position of the single feature in the design data space.

Abstract: Methods and systems for adaptive sampling for semiconductor inspection recipe creation, defect review, and metrology are provided. The embodiments provide image processing and pattern recognition algorithms and an adaptive sampling method for extracting critical areas from SEM image patches for use in a wafer inspection system when design data for a semiconductor chip is not available. The embodiments also provide image processing and pattern recognition algorithms for efficiently discovering critical defects and significant deviations in the normal manufacturing process, using the output from a wafer inspection system and an adaptive sampling method to select wafer locations to be examined on a high resolution review or metrology tool.

Abstract: Various embodiments for extended defect sizing range for wafer inspection are provided. One inspection system includes an illumination subsystem configured to direct light to the wafer. The system also includes an image sensor configured to detect light scattered from wafer defects and to generate output responsive to the scattered light. The image sensor is also configured to not have an anti-blooming feature such that when a pixel in the image sensor reaches full well capacity, excess charge flows from the pixel to one or more neighboring pixels in the image sensor. The system further includes a computer subsystem configured to detect the defects on the wafer using the output and to determine a size of the defects on the wafer using the output generated by a pixel and any neighboring pixels of the pixel to which the excess charge flows.

Abstract: Methods and systems for detecting defects on a wafer using defect-specific and multi-channel information are provided. One method includes acquiring information for a target on a wafer. The target includes a pattern of interest (POI) formed on the wafer and a known defect of interest (DOI) occurring proximate to or in the POI. The method also includes detecting the known DOI in target candidates by identifying potential DOI locations based on images of the target candidates acquired by a first channel of an inspection system and applying one or more detection parameters to images of the potential DOI locations acquired by a second channel of the inspection system. Therefore, the image(s) used for locating potential DOI locations and the image(s) used for detecting defects can be different.

Abstract: Methods and systems for determining design coordinates for defects detected on a wafer are provided. One method includes aligning a design for a wafer to defect review tool images for defects detected in multiple swaths on the wafer by an inspection tool, determining a position of each of the defects in design coordinates based on results of the aligning, separately determining a defect position offset for each of the multiple swaths based on the swath in which each of the defects was detected (swath correction factor), the design coordinates for each of the defects, and a position for each of the defects determined by the inspection tool, and determining design coordinates for the other defects detected in the multiple swaths by the inspection tool by applying the appropriate swath correction factor to those defects.

Abstract: Illumination subsystems of a metrology system, metrology systems, and methods for illuminating a specimen for metrology measurements are provided. One illumination subsystem includes a light source configured to generate coherent pulses of light and a dispersive element positioned in the path of the coherent pulses of light, which is configured to reduce coherence of the pulses of light by mixing spatial and temporal characteristics of light distribution in the pulses of light. The illumination subsystem also includes an electro-optic modulator positioned in the path of the pulses of light exiting the dispersive element and which is configured to reduce the coherence of the pulses of light by temporally modulating the light distribution in the pulses of light. The illumination subsystem is configured to direct the pulses of light from the electro-optic modulator to a specimen positioned in the metrology system.

Abstract: Various metrology systems and methods are provided. One metrology system includes a light source configured to produce a diffraction-limited light beam, an apodizer configured to shape the light beam in the entrance pupil of illumination optics, and optical elements configured to direct the diffraction-limited light beam from the apodizer to an illumination spot on a grating target on a wafer and to collect scattered light from the grating target. The metrology system further includes a field stop and a detector configured to detect the scattered light that passes through the field stop. In addition, the metrology system includes a computer system configured to determine a characteristic of the grating target using output of the detector.

Abstract: Illumination subsystems of a metrology or inspection system, metrology systems, inspection systems, and methods for illuminating a specimen for metrology measurements or for inspection are provided. One illumination subsystem includes a light source configured to generate coherent pulses of light and a dispersive element positioned in the path of the coherent pulses of light, which is configured to reduce coherence of the pulses of light by mixing spatial and temporal characteristics of light distribution in the pulses of light. The illumination subsystem also includes an electro-optic modulator positioned in the path of the pulses of light exiting the dispersive element and which is configured to reduce the coherence of the pulses of light by temporally modulating the light distribution in the pulses of light. The illumination subsystem is configured to direct the pulses of light from the electro-optic modulator to a specimen.

Abstract: Methods and systems for detecting defects on a wafer are provided. One method includes identifying one or more characteristics of first raw output generated for a wafer that correspond to one or more geometrical characteristics of patterned features formed on the wafer and assigning individual output in second raw output generated for the wafer to different segments based on the identified one or more characteristics of the first raw output and based on the individual output in the second raw output and individual output in the first raw output that were generated at substantially the same locations on the wafer such that the one or more geometrical characteristics of the patterned features that correspond to each of the different segments in the second raw output are different.

Abstract: Methods for inspecting a wafer and/or predicting one or more characteristics of a device being formed on a wafer are provided. One method includes acquiring images for multiple die printed on a wafer, each of which is printed by performing a double patterning lithography process on the wafer and which include two or more die printed at nominal values of overlay for the double patterning lithography process and one or more die printed at modulated values of the overlay; comparing the images acquired for the multiple die printed at the nominal values to the images acquired for the multiple die printed at the modulated values; and detecting defects in the multiple die printed at the modulated values based on results of the comparing step.

Abstract: Methods and systems for generating unbiased wafer defect samples are provided. One method includes selecting the defects detected by each of multiple scans performed on a wafer that have the most diversity in one or more defect attributes such that a diverse set of defects are selected across each scan. In addition, the method may include selecting the defects such that any defect that is selected and is common to two or more of the scans is not selected twice and any defects that are selected are diverse with respect to the common, selected defect. Furthermore, no sampling, binning, or classifying of the defects may be performed prior to selection of the defects such that the sampled defects are unbiased by any sampling, binning, or classifying method.

Abstract: Methods, systems, and structures for monitoring incident beam position in a wafer inspection system are provided. One structure includes a feature formed in a chuck configured to support a wafer during inspection by the wafer inspection system. The chuck rotates the wafer in a theta direction and simultaneously translates the wafer in a radial direction during the inspection. An axis through the center of the feature is aligned with a radius of the chuck such that a position of the axis relative to an incident beam of the wafer inspection system indicates changes in the incident beam position in the theta direction.

Abstract: Multi-spectral defect inspection for 3D wafers is provided. One system configured to detect defects in one or more structures formed on a wafer includes an illumination subsystem configured to direct light in discrete spectral bands to the one or more structures formed on the wafer. At least some of the discrete spectral bands are in the near infrared (NIR) wavelength range. Each of the discrete spectral bands has a bandpass that is less than 100 nm. The system also includes a detection subsystem configured to generate output responsive to light in the discrete spectral bands reflected from the one or more structures. In addition, the system includes a computer subsystem configured to detect defects in the one or more structures on the wafer using the output.

Abstract: Systems and methods for discrete polarization scatterometry are provided.

Abstract: Systems and methods for inspecting a wafer are provided. One system includes an illumination subsystem configured to illuminate the wafer; a collection subsystem configured to collect light scattered from the wafer and to preserve the polarization of the scattered light; an optical element configured to separate the scattered light collected in different segments of the collection numerical aperture of the collection subsystem, where the optical element is positioned at a Fourier plane or a conjugate of the Fourier plane of the collection subsystem; a polarizing element configured to separate the scattered light in one of the different segments into different portions of the scattered light based on polarization; and a detector configured to detect one of the different portions of the scattered light and to generate output responsive to the detected light, which is used to detect defects on the wafer.

Abstract: Illumination subsystems for multi-spot wafer inspection are provided. One illumination subsystem includes a diffractive optical element configured to separate an illumination light beam into multiple light beams and a refractive lens array positioned in the path of the multiple light beams. The refractive lens array is configured to relay the laser beam waist at the diffractive optical element onto a wafer surface and to separately and simultaneously focus each of the multiple light beams to a wafer for inspection.

Abstract: Various metrology systems and methods are provided. One metrology system includes a light source configured to produce a diffraction-limited light beam, an apodizer configured to shape the light beam in the entrance pupil of illumination optics, and optical elements configured to direct the diffraction-limited light beam from the apodizer to an illumination spot on a grating target on a wafer and to collect scattered light from the grating target. The metrology system further includes a field stop and a detector configured to detect the scattered light that passes through the field stop. In addition, the metrology system includes a computer system configured to determine a characteristic of the grating target using output of the detector.