Abstract: Disclosed are apparatus and methods for detecting defects on a semiconductor sample. An optical inspector is first used to inspect a semiconductor sample with an aggressively predefined threshold selected to detect candidate defect and nuisance sites at corresponding locations across the sample. A high-resolution distributed probe inspector includes an array of miniature probes that are moved relative to the sample to scan and obtain a high-resolution image of each site to detect and separate the candidate defect sites from the nuisance sites. A higher-resolution probe is then used to obtain a higher-resolution image of each candidate site to obtain a high-resolution image of each site to separate real defects that adversely impact operation of any devices on the sample from the candidate defects.

Abstract: Methods and systems for performing overlay and edge placement errors of device structures based on x-ray diffraction measurement data are presented. Overlay error between different layers of a metrology target is estimated based on the intensity variation within each x-ray diffraction order measured at multiple, different angles of incidence and azimuth angles. The estimation of overlay involves a parameterization of the intensity modulations of common orders such that a low frequency shape modulation is described by a set of basis functions and a high frequency overlay modulation is described by an affine-circular function including a parameter indicative of overlay. In addition to overlay, a shape parameter of the metrology target is estimated based on a fitting analysis of a measurement model to the intensities of the measured diffraction orders. In some examples, the estimation of overlay and the estimation of one or more shape parameter values are performed simultaneously.

Abstract: Wafer edge profile images are analyzed at locations around a bonded wafer, which may have a top wafer and a carrier wafer. An offset curve is generated based on the wafer edge profile images. Displacement of the top wafer to the carrier wafer is determined based on the offset curve. The wafer edge profile images may be generated at multiple locations around the wafer. The wafer edge profile images may be shadowgram images. A system to determine displacement of the top wafer to the carrier wafer can include an imaging system connected with a controller.

Abstract: Block-to-block reticle inspection includes acquiring a swath image of a portion of a reticle with a reticle inspection sub-system, identifying a first occurrence of a block in the swatch image and at least a second occurrence of the block in the swath image substantially similar to the first occurrence of the block and determining at least one of a location, one or more geometrical characteristics of the block and a spatial offset between the first occurrence of the block and the at least a second occurrence of the block.

Abstract: A voltage contrast imaging defect detection system includes a voltage contrast imaging tool and a controller coupled to the voltage contrast imaging tool. The controller is configured to generate one or more voltage contrast imaging metrics for one or more structures on a sample, determine one or more target areas on the sample based on the one or more voltage contrast imaging metrics, receive a voltage contrast imaging dataset for the one or more target areas on the sample from the voltage contrast imaging tool, and detect one or more defects based on the voltage contrast imaging dataset.

Abstract: Angle-resolved reflectometers and reflectometry methods are provided, which comprise a coherent light source, an optical system arranged to scan a test pattern using a spot of coherent light from the light source to yield realizations of the light distribution in the collected pupil, wherein the spot covers a part of the test pattern and the scanning is carried out optically or mechanically according to a scanning pattern, and a processing unit arranged to generate a composite image of the collected pupil distribution by combining the pupil images. Metrology systems and methods are provided, which reduce diffraction errors by estimating, quantitatively, a functional dependency of measurement parameters on aperture sizes and deriving, from identified diffraction components of the functional dependency which relate to the aperture sizes, correction terms for the measurement parameters with respect to the measurement conditions.

Abstract: An overlay metrology system may include a controller to generate optical tool error adjustments for a hybrid overlay target including optically-resolvable features and device-scale features by measuring a difference between an optical overlay measurement based on the optically-resolvable features and a device-scale overlay measurement based on the device-scale features, generate target-to-device adjustments for the hybrid overlay target based on positions of features within the device area, determine device-relevant overlay measurements for one or more locations in the device area based on at least one of the optical overlay measurement, the optical tool error adjustments, or the target-to-device adjustments, and provide overlay correctables for the device area to a lithography tool to modify exposure conditions for at least one subsequent exposure based on the device-relevant overlay measurements.

Abstract: A method includes receiving one or more images of three or more die of a wafer, determining a median intensity value of a set of pixel intensity values acquired from a same location on each of the three or more die, determining a difference intensity value for the set of pixel intensity values by comparing the median intensity value of the set of pixel intensity values to each pixel intensity value, grouping the pixel intensity values into an intensity bin based on the median intensity value of the set of pixel intensity values, generating an initial noise boundary based on a selected difference intensity value in the intensity bin, generating a final noise boundary by adjusting the initial noise boundary, generating a detection boundary by applying a threshold to the final noise boundary, and classifying one or more pixel intensity values outside the detection boundary as a defect.

Abstract: A photocathode can include a body fabricated of a wide bandgap semiconductor material, a metal layer, and an alkali halide photocathode emitter. The body may have a thickness of less than 100 nm and the alkali halide photocathode may have a thickness less than 10 nm. The photocathode can be illuminated with a dual wavelength scheme.

Abstract: Disclosed are methods and apparatus for detecting defects or reviewing defects in a semiconductor sample. The system has a brightfield (BF) module for directing a BF illumination beam onto a sample and detecting an output beam reflected from the sample in response to the BF illumination beam. The system has a modulated optical reflectance (MOR) module for directing a pump and probe beam to the sample and detecting a MOR output beam from the probe spot in response to the pump beam and the probe beam. The system includes a processor for analyzing the BF output beam from a plurality of BF spots to detect defects on a surface or near the surface of the sample and analyzing the MOR output beam from a plurality of probe spots to detect defects that are below the surface of the sample.

Abstract: A defect detection method includes acquiring a reference image; selecting a target region of the reference image; identifying, based on a matching metric, one or more comparative regions of the reference image corresponding to the target region; acquiring a test image; masking the test image with the target region of the reference image and the one or more comparative regions of the reference image; defining a defect threshold for the target region in the test image based on the one or more comparative regions in the test image; and determining whether the target region of the test image contains a defect based on the defect threshold.

Abstract: Imaging metrology targets and methods are provided, which combine one-dimensional (1D) elements designed to provide 1D imaging metrology signals along at least two measurement directions and two-dimensional (2D) elements designed to provide at least one 2D imaging metrology overlay signal. The target area of the 1D elements may enclose the 2D elements or the target areas of the 1D and 2D elements may be partially or fully congruent. The compound targets are small, possibly multilayered, and may be designed to be process compatible (e.g., by segmentation of the elements, interspaces between elements and element backgrounds) and possibly be produced in die. Two dimensional elements may be designed to be periodic to provide additional one dimensional metrology signals.

Abstract: Methods and systems for quantifying and correcting for non-uniformities in images used for metrology operations are disclosed. A metrology area image of a wafer and a design clip may be used. The metrology area image may be a scanning electron microscope image. The design clip may be the design clip of the wafer or a synthesized design clip. Tool distortions, including electron beam distortions, can be quantified and corrected. The design clip can be applied to the metrology area image to obtain a synthesized image such that one or more process change variations are suppressed and one or more tool distortions are enhanced.

Abstract: A system for measuring overlay from a multi-layer overlay target for use in imaging based metrology is disclosed. The system is configured for measuring overlay from a multi-layer overly target that includes three or more target structures, wherein a first target structure is disposed in a first process layer, a second target structure is disposed in a second process layer, and at least a third target structure is disposed in at least a third process layer. The system includes an illumination source configured to illuminate the target structures of the multi-layer overlay target, a detector configured to collect light reflected from the target structures, and one or more processors configured to execute a set of program instructions to determine overlay error between two or more structures based on the collected light from the plurality of targets.

Abstract: An optical relay system includes four or more reflective optical elements oriented in a tilted configuration. Each of the four or more reflective optical elements is tilted about one of four or more tilt axes. Further, the four or more tilt axes are oriented to correct for aberrations induced by the tilted configuration.

Abstract: Scatterometry overlay targets and measurement methods are provided, which are configured to detect and eliminate process-related errors and illumination-related errors from overlay measurements of the targets. Targets comprise at least three cells associated with a measurement direction, wherein at least two of the cells comprise periodic structures at different target layers, having a same pitch and opposite offsets between the two cells, and at least an additional cell comprises a periodic structure with the same pitch at only one of the target layers. The additional cell(s) are used to detect irregularities in the respective periodic structure(s), enable estimation of process quality, provide reference images, enhance metrology simulations and provide mitigation of errors in critical process steps. Measurement methods incorporate scatterometry measurements ion the additional cell(s) for these purposes.

Abstract: This system and method minimize an effect of haze to signal-to-noise ratio and compensate for haze on the haze map. A first mask with a first aperture is disposed along the path of the light beam between a light source and a collector. A first actuator moves the first mask along a tangential direction. A second mask with a second aperture is disposed along the path of the light beam between the first mask and the collector. A second actuator moves the second mask along a radial direction perpendicular to the tangential direction. The first mask and the second mask are independently movable along the tangential direction and the radial direction using the first actuator and the second actuator.

Abstract: A die-die inspection image can be aligned using a method or system configured to receive a reference image and a test image, determine a global offset and rotation angle from local sections on the reference image and test image, and perform a rough alignment de-skew of the test image prior to performing a fine alignment.

Abstract: A system for separating plasma pumping light and collected broadband light includes a pump source configured to generate pumping illumination including at least a first wavelength, a gas containment element for containing a volume of gas, a collector configured to focus the pumping illumination from the pumping source into the volume of gas to generate a plasma within the volume of gas, wherein the plasma emits broadband radiation including at least a second wavelength and an illumination separation prism element positioned between a reflective surface of the collector and the pump source and arranged to spatially separate the pumping illumination including the first wavelength and the emitted broadband radiation including at least a second wavelength emitted from the plasma.

Abstract: A laser-sustained plasma light source includes a plasma lamp configured to contain a volume of gas and receive illumination from a pump laser in order to generate a plasma. The plasma lamp includes one or more transparent portions transparent to illumination from the pump laser and at least a portion of the broadband radiation emitted by the plasma. The one or more transparent portions are formed from a transparent material having elevated hydroxide content above 700 ppm.