Abstract: A high performance objective having very small central obscuration, an external pupil for apertureing and Fourier filtering, loose manufacturing tolerances, large numerical aperture, long working distance, and a large field of view is presented. The objective is preferably telecentric. The design is ideally suited for both broad-band bright-field and laser dark field imaging and inspection at wavelengths in the UV to VUV spectral range.

Abstract: Systems configured to provide illumination of a specimen or to inspect a specimen are provided. One system includes a light source configured to generate pulses of light at a repetition rate. The system also includes optical elements arranged in a first interferometer configuration followed by a second interferometer configuration. The optical elements are configured to quadruple the repetition rate of the pulses of light. In addition, the system includes an electro-optic phase modulator configured to receive the pulses of light from the optical elements and to alter a polarization of the pulses of light at a rate of one half the quadrupled repetition rate such that the pulses of light can be directed to the specimen as effectively continuous-wave uniformly polarized illumination.

Abstract: Computer-implemented methods, carrier media, and systems for detecting defects on a wafer based on multi-core architecture are provided. One computer-implemented method for detecting defects on a wafer includes acquiring output for the wafer generated by an inspection system. Dies are formed on the wafer, and multiple cores are formed in the dies. The method also includes detecting defects on the wafer by comparing the output for a first of the multiple cores to the output for a second of the multiple cores. The first and second of the multiple cores are formed in the same die, different dies, or the same die and different dies.

Abstract: Methods and systems for evaluating and controlling a lithography process are provided. For example, a method for reducing within wafer variation of a critical metric of a lithography process may include measuring at least one property of a resist disposed upon a wafer during the lithography process. A critical metric of a lithography process may include, but may not be limited to, a critical dimension of a feature formed during the lithography process. The method may also include altering at least one parameter of a process module configured to perform a step of the lithography process to reduce within wafer variation of the critical metric. The parameter of the process module may be altered in response to at least the one measured property of the resist.

Abstract: Systems and methods for determining a characteristic of a specimen are provided. One system includes an illumination subsystem configured to direct light to a first set of spots on the specimen at a normal angle of incidence and to simultaneously direct light to a second set of spots on the specimen at an oblique angle of incidence. The system also includes a detection subsystem configured to detect light scattered from the first and second sets of spots simultaneously and to generate first output responsive to the light scattered from the first set of spots and second output responsive to the light scattered from the second set of spots. The first and second outputs can be used to determine the characteristic of the specimen.

Abstract: Systems and methods for measuring one or more characteristics of patterned features on a specimen are provided. One system includes an optical subsystem configured to acquire measurements of light scattered from the patterned features on the specimen at multiple angles of incidence, multiple azimuthal angles, and multiple wavelengths simultaneously. The system also includes a processor configured to determine the one or more characteristics of the patterned features from the measurements. One method includes acquiring measurements of light scattered from the patterned features on the specimen at multiple angles of incidence, multiple azimuthal angles, and multiple wavelengths simultaneously. The method also includes determining the one or more characteristics of the patterned features from the measurements.

Abstract: Methods and systems for monitoring semiconductor fabrication processes are provided. A system may include a stage configured to support a specimen and coupled to a measurement device. The measurement device may include an illumination system and a detection system. The illumination system and the detection system may be configured such that the system may be configured to determine multiple properties of the specimen. For example, the system may be configured to determine multiple properties of a specimen including, but not limited to, a presence of macro and micro defects. In this manner, a measurement device may perform multiple optical and/or non-optical metrology and/or inspection techniques.

Abstract: An inspection system and method is provided herein for increasing the detection range of the inspection system. According to one embodiment, the inspection system may include a photodetector having a plurality of stages, which are adapted to convert light scattered from a specimen into an output signal, and a voltage divider network coupled for extending the detection range of the photodetector (and thus, the detection range of the inspection system) by saturating at least one of the stages. This forces the photodetector to operate in a non-linear manner. However, measurement inaccuracies are avoided by calibrating the photodetector output to remove any non-linear effects that may be created by intentionally saturating the at least one of the stages. In one example, a table of values may be generated during a calibration phase to convert the photodetector output into an actual amount of scattered light.

Abstract: Methods and systems for creating a recipe for a defect review process are provided. One method includes determining an identity of a specimen on which the defect review process will be performed. The method also includes identifying inspection results for the specimen based on the identity. In addition, the method includes creating the recipe for the defect review process based on the inspection results. One system includes a sensor configured to generate output responsive to an identity of a specimen on which the defect review process will be performed. The system also includes a processor configured to determine the identity of the specimen using the output, to identify inspection results for the specimen based on the identity, and to create the recipe for the defect review process based on the inspection results.

Abstract: Accordingly, the present invention provides methods and apparatus for performing a darkfield inspection on a specimen having periodic structures thereon while substantially reducing or eliminating the long range ringing response, which is typically produced by a traditional Fourier filter mask used to eliminate the diffraction caused by the periodic structures. In one embodiment, an apparatus for inspecting a specimen by detecting optical beams scattered from the specimen. The apparatus includes a beam generator for providing and directing an incident beam towards a specimen and an array subtraction device for substantially subtracting a periodic component from an output beam scattered from the specimen in response to the incident beam. The periodic component corresponds to at least one periodic structure on the specimen, and the subtraction is performed so as to substantially reduce or eliminate a ringing response from the output beam.

Abstract: Computer-implemented methods and systems for determining a configuration for a light scattering inspection system are provided. One computer-implemented method includes determining a three-dimensional map of signal-to-noise ratio values for data that would be acquired for a specimen and a potential defect on the specimen by the light scattering inspection system across a scattering hemisphere of the inspection system. The method also includes determining one or more portions of the scattering hemisphere in which the signal-to-noise ratio values are higher than in other portions of the scattering hemisphere based on the three-dimensional map. In addition, the method includes determining a configuration for a detection subsystem of the inspection system based on the one or more portions of the scattering hemisphere.

Abstract: Inspection systems, circuits, and methods are provided to enhance defect detection by reducing thermal damage to large particles by dynamically altering the incident laser beam power level supplied to the specimen during a surface inspection scan. In one embodiment, an inspection system includes an illumination subsystem for directing light to a specimen at a first power level, a detection subsystem for detecting light scattered from the specimen, and a power attenuator subsystem for dynamically altering the power level directed to the specimen based on the scattered light detected from the specimen. For example, the power attenuator subsystem may reduce the directed light to a second power level, which is lower than the first, if the detected scattered light exceeds a predetermined threshold level. In addition reducing thermal damage, the systems and methods described herein may be used to extend the measurement detection range of an inspection system by providing a variable-power inspection system.

Abstract: Disclosed is a method for determining an overlay error between at least two layers in a multiple layer sample. An imaging optical system is used to measure a plurality of measured optical signals from a plurality of periodic targets on the sample. The targets each have a first structure in a first layer and a second structure in a second layer. There are predefined offsets between the first and second structures. A scatterometry overlay technique is then used to analyze the measured optical signals of the periodic targets and the predefined offsets of the first and second structures of the periodic targets to thereby determine an overlay error between the first and second structures of the periodic targets.

Abstract: A system that includes an optical subsystem and an atomic force microscope probe is provided. The optical subsystem is configured to generate positional information about a location on a surface of the specimen. The system is configured to position the probe proximate the location based on the positional information. One method includes generating positional information about a location on a surface of a specimen with an optical subsystem. The method also includes positioning an atomic force microscopy probe proximate the location based on the positional information. Another system includes an optical subsystem configured to measure overlay of a wafer using scatterometry. The system also includes an atomic force microscope configured to measure a characteristic of a feature on the wafer. An additional method includes measuring overlay of a wafer using scatterometry. The method also includes measuring a characteristic of a feature on the wafer using atomic force microscopy.

Abstract: Inspection systems, circuits and methods are provided to enhance defect detection by addressing saturation levels of the amplifier and analog-digital circuitry as a limiting factor of the measurement detection range of an inspection system. In accordance with one embodiment of the invention, a method for inspecting a specimen includes directing light to the specimen and detecting light scattered from the specimen. However, the step of detecting may use only one photodetector for detecting the light scattered from the specimen and for converting the light into an electrical signal. The step of detecting also includes generating a first signal and a second signal in response to the electrical signal, where the second signal differs from the first. For example, the first signal may be generated to have a higher resolution than the second signal for detecting substantially lower levels of the scattered light.

Abstract: Methods that include acquiring aerial images of a reticle for different values of a member of a set of lithographic variables are provided. One method also includes determining a presence of an anomaly in a design pattern of the reticle by comparing at least one pair of the aerial images corresponding to at least two of the different values. A different method includes comparing at least one pair of the aerial images corresponding to at least two of the different values and determining an area on the reticle where a lithography process using the reticle is most susceptible to failure based on the results of the comparison. Another embodiment includes determining a presence of transient repeating defects on the reticle by subtracting non-transient defects from the aerial images and comparing at least one pair of the aerial images corresponding to at least two of the different values.

Abstract: Wafer inspection systems and methods are provided. One inspection system includes a module measurement cell coupled to a host inspection system by a wafer handler. The module measurement cell is configured to inspect a wafer using one or more modes prior to inspection of the wafer by the host inspection system. The one or more modes include backside inspection, edge inspection, frontside macro defect inspection, or a combination thereof. Another inspection system includes two or more low resolution electronic sensors arranged at multiple viewing angles. The sensors are configured to detect light returned from a wafer substantially simultaneously. A method for analyzing inspection data includes selecting a template corresponding to a support device that contacts a backside of a wafer prior to inspection of the backside of the wafer. The method also includes subtracting data representing the template from inspection data generated by inspection of the backside of the wafer.

Abstract: Inspection systems, circuits and methods are provided to enhance defect detection by addressing anode saturation as a limiting factor of the measurement detection range of a photomultiplier tube (PMT) detector. In accordance with one embodiment of the invention, a method for inspecting a specimen includes directing light to the specimen and detecting light scattered from the specimen. The step of detecting may include monitoring an anode current of the PMT detector, and detecting features, defects or light scattering properties of the specimen using the anode current until the anode current reaches a predetermined threshold. Thereafter, the method may use a dynode current of the PMT for detecting the features, defects or light scattering properties of the specimen.

Abstract: An illumination subsystem configured to provide illumination for a measurement system includes first and second light sources configured to generate light for measurements in different wavelength regimes. The illumination subsystem also includes a TIR prism configured to be moved into and out of an optical path from the first and second light sources to the measurement system. If the TIR prism is positioned out of the optical path, light from only the first light source is directed along the optical path. If the TIR prism is positioned in the optical path, light from only the second light source is directed along the optical path. Various measurement systems are also provided. One measurement system includes an optical subsystem configured to perform measurements of a specimen using light in different wavelength regimes directed along a common optical path. The different wavelength regimes include vacuum ultraviolet, ultraviolet, visible, and near infrared wavelength regimes.

Abstract: The present invention is a chuck having a vacuum groove that is capable of holding a wafer as the chuck rotates on a spindle. As the chuck rotates the air pressure above the center of the wafer is reduced. In order to reduce the bowing of the wafer that can result from this low pressure area above the wafer, the present invention introduces venturi holes in the chuck which reduces the air pressure in the area below the wafer. In order to prevent the air pressure in the area below the wafer from decreasing too far, the present invention uses air inlet holes to balance the affect of the venturi holes in order to substantially balance the air pressure above and below the wafer which results in significantly less bowing of the wafer when compared to conventional systems. The present invention accomplishes this without requiring sensors or other active measuring devices to help reduce the bowing of the wafer.