Abstract: Methods for determining an electrical parameter of an insulating film are provided. One method includes measuring a surface potential of a leaky insulating film without inducing leakage across the insulating film and determining the electrical parameter from the surface potential. Another method includes applying an electrical field across the insulating film. Leakage across the insulating film caused by the electrical field is negligible. The method also includes measuring a surface potential of the specimen and determining a potential of the substrate. In addition, the method includes determining a pure voltage across the insulating film from the surface potential and the substrate potential. The method further includes determining the electrical parameter from the pure voltage. The electrical parameter may be capacitance or electrical thickness of the insulating film.

Abstract: Serrated Fourier filters and inspection systems are provided. One Fourier filter includes one or more blocking elements configured to block a portion of light from a wafer. The Fourier filter also includes periodic serrations formed on edges of the one or more blocking elements. The periodic serrations define a transition region of the one or more blocking elements. The periodic serrations are configured to vary transmission across the transition region such that variations in the transmission across the transition region are substantially smooth. One inspection system includes a Fourier filter configured as described above and a detector that is configured to detect light transmitted by the Fourier filter. Signals generated by the detector can be used to detect the defects on the wafer.

Abstract: Systems and methods for reducing alteration of a specimen during by charged particle based and other measurements systems are provided. One system configured to reduce alteration of a specimen during analysis includes a vacuum chamber in which the specimen is disposed during the analysis and an element disposed within the vacuum chamber. A surface of the element is cooled such that molecules in the vacuum chamber are adsorbed onto the surface and cannot cause alteration of a characteristic of the specimen during the analysis. One system configured to analyze a specimen includes an analysis subsystem configured to analyze the specimen while the specimen is disposed in a vacuum chamber and an element disposed within the vacuum chamber. A surface of the element is cooled such that molecules in the vacuum chamber are adsorbed onto the surface and cannot cause alteration of a characteristic of the specimen during the analysis.

Abstract: Multi-spot illumination and collection optics for highly tilted wafer planes are provided. One system configured to provide illumination of a wafer for inspection includes one or more optical elements configured to direct light to an entrance pupil. The system also includes a diffractive optical element positioned at the entrance pupil and configured to separate the light into individual beams. In addition, the system includes a set of optical elements configured to focus the individual beams to a wafer plane to form spatially separated spots on the wafer plane. The wafer plane is arranged at an oblique angle to the entrance pupil.

Abstract: Disclosed is a method of determining an overlay error between two layers of a multiple layer sample. For a plurality of periodic targets that each have a first structure formed from a first layer and a second structure formed from a second layer of the sample, an optical system is employed to thereby measure an optical signal from each of the periodic targets. There are predefined offsets between the first and second structures. An overlay error is determined between the first and second structures by analyzing the measured optical signals from the periodic targets using a scatterometry overlay technique based on the predefined offsets.

Abstract: Methods and systems for inspecting a reticle are provided. In an embodiment, a system may include an inspection subsystem configured to form a first aerial image of the reticle. The first aerial image may be used to detect defects on the reticle. The system may also include a review subsystem coupled to the inspection subsystem. For example, the inspection and review subsystems may have common optics, separate optics and a common stage, or separate stages and a common handler. The review subsystem may be configured to form a second aerial image of the reticle. The second aerial image may be used to analyze the defects. In another embodiment, the system may include an image computer configured to receive image data from the inspection and review subsystems representing the first and second aerial images. The image computer may also be configured to perform one or more functions on the image data.

Abstract: Various methods and systems for detection of selected defects particularly in relatively noisy inspection data are provided. One method includes applying a spatial filter algorithm to raw inspection data acquired across an area on a substrate to determine a first portion of the raw inspection data that has a higher probability of being a selected type of defect than a second portion of the raw inspection data. The selected type of defect includes a non-point defect. The method also includes generating a raw two-dimensional map illustrating the first portion of the raw inspection data. In addition, the method includes searching the raw two-dimensional map for an event that has spatial characteristics that approximately match spatial characteristics of the selected type of defect. The method further includes determining if the event corresponds to a defect having the selected type.

Abstract: Systems and methods for inspecting a wafer with increased sensitivity are provided. One system includes an inspection subsystem configured to direct light to a spot on the wafer and to generate output signals responsive to light scattered from the spot on the wafer. The system also includes a gas flow subsystem configured to replace a gas located proximate to the spot on the wafer with a medium that scatters less of the light than the gas thereby increasing the sensitivity of the system. In addition, the system includes a processor configured to detect defects on the wafer using the output signals.

Abstract: Methods and apparatus for producing a semiconductor. A production reticle having a pattern that includes circuit features, phase shift target structures and overlay target structures is provided. The pattern is transferred multiple times across a test wafer surface for various focus levels to form a focus matrix. The pattern shift of the phase shift target structures is measured using an overlay metrology tool. The phase difference is calculated for each phase shift target structure, based on the pattern shift and the phase shift target structure focus level to qualify the phase difference of the production reticle. The pattern is transferred onto a production wafer when the phase difference meets desired limits. The pattern shift of the overlay target structures transferred to the production wafer is measured using an overlay metrology tool. The pattern placement error of the overlay target structures is calculated and the pattern placement error is qualified.

Abstract: Methods and systems for measuring a characteristic of a substrate or preparing a substrate for analysis are provided. One method for measuring a characteristic of a substrate includes removing a portion of a feature on the substrate using an electron beam to expose a cross-sectional profile of a remaining portion of the feature. The feature may be a photoresist feature. The method also includes measuring a characteristic of the cross-sectional profile. A method for preparing a substrate for analysis includes removing a portion of a material on the substrate proximate to a defect using chemical etching in combination with an electron beam. The defect may be a subsurface defect or a partially subsurface defect. Another method for preparing a substrate for analysis includes removing a portion of a material on a substrate proximate to a defect using chemical etching in combination with an electron beam and a light beam.

Abstract: Various systems for measurement of a specimen are provided. One system includes an optical subsystem configured to perform measurements of a specimen using vacuum ultraviolet light and non-vacuum ultraviolet light. This system also includes a purging subsystem that is configured to maintain a purged environment around the optical subsystem during the measurements. Another system includes a cleaning subsystem configured to remove contaminants from a specimen prior to measurement. In one embodiment, the cleaning subsystem may be a laser-based cleaning subsystem that is configured to remove contaminants from a localized area on the specimen. The system also includes an optical subsystem that is configured to perform measurements of the specimen using vacuum ultraviolet light. The optical subsystem is disposed within a purged environment. In some embodiments, the system may include a differential purging subsystem that is configured to provide the purged environment for the optical subsystem.

Abstract: A method for determining a property of an insulating film is provided. The method may include obtaining a charge density measurement of the film, a surface voltage potential of the film relative to a bulk voltage potential of the substrate, and a rate of voltage decay of the film. The method may also include determining the property of the film using the charge density, the surface voltage potential, and the rate of voltage decay. A method for determining a thickness of an insulating film is provided. The method may include depositing a charge on the film, measuring a surface voltage potential of the film relative to a bulk voltage potential of the substrate, and measuring a rate of voltage decay of the film. The method may also include determining a thickness of the film using the rate of voltage decay and a theoretical model relating to current leakage and film thickness.

Abstract: Methods and systems for measurements of a substrate are provided. One system includes a non-optical subsystem configured to perform first measurements on a substrate. The system also includes an optical subsystem coupled to the non-optical subsystem. The optical subsystem is configured to perform second measurements on the substrate. In addition, the system includes a processor coupled to the subsystems. The processor is configured to calibrate one of the subsystems using the measurements performed by the other subsystem. One method includes performing first measurements on a substrate using a non-optical subsystem and performing second measurements on the substrate using an optical subsystem that is coupled to the non-optical subsystem. The method also includes calibrating one of the subsystems using the measurements performed by the other subsystem.

Abstract: All-reflective optical systems for broadband wafer inspection are provided. One system configured to inspect a wafer includes an optical subsystem. All light-directing components of the optical subsystem are reflective optical components except for one or more refractive optical components, which are located only in substantially collimated space. The refractive optical component(s) may include, for example, a refractive beamsplitter element that can be used to separate illumination and collection pupils. The optical subsystem may also include one or more reflective optical components located in substantially collimated space. The optical subsystem is configured for inspection of the wafer across a waveband of greater than 20 nm. In some embodiments, the optical subsystem is configured for inspection of the wafer at wavelengths less than and greater than 200 nm.

Abstract: A surface inspection apparatus and method are disclosed. In particular, the method and apparatus are capable of inspecting a surface in two (or more) optical regimes thereby enhancing the defect detection properties of such method and apparatus. A method involves illuminating the surface with light in a first wavelength range and a second wavelength range. The first wavelength range selected so that the surface is opaque to the light of the first wavelength range so that a resultant optical signal is produced that is predominated by diffractive and scattering properties of the surface. The second wavelength range is selected so that the surface is at least partially transmissive to light in the second wavelength range so that another resultant optical signal is produced that is predominated by thin film optical properties of the surface. The resultant optical signals are detected and processed to detect defects in the surface. Devices for implementing such methods are also disclosed.

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 property of a specimen prior to, during, or subsequent to lithography. In this manner, a measurement device may perform multiple optical and/or non-optical metrology and/or inspection techniques.

Abstract: A method for measurement of a specimen is provided. The method includes measuring spectroscopic ellipsometric data of the specimen. The method also includes determining a nitrogen concentration of a nitrided oxide gate dielectric formed on the specimen from the spectroscopic ellipsometric data. A computer-implemented method for analysis of a specimen is also provided. This method includes determining a nitrogen concentration of a nitrided oxide gate dielectric formed on the specimen from spectroscopic ellipsometric data generated by measurement of the specimen. In some embodiments, the methods described above may include determining an index of refraction of the nitrided oxide gate dielectric from the spectroscopic ellipsometric data and determining the nitrogen concentration from the index of refraction. In another embodiment, the methods described above may include measuring reflectometric data of the specimen.

Abstract: Fourier filters and wafer inspection systems are provided. One embodiment relates to a one-dimensional Fourier filter configured to be included in a bright field inspection system such that the bright field inspection system can be used for broadband dark field inspection of a wafer. The Fourier filter includes an asymmetric illumination aperture configured to be positioned in an illumination path of the inspection system. The Fourier filter also includes an asymmetric imaging aperture complementary to the illumination aperture. The imaging aperture is configured to be positioned in a light collection path of the inspection system such that the imaging aperture blocks light reflected and diffracted from structures on the wafer and allows light scattered from defects on the wafer to pass through the imaging aperture.

Abstract: Multi-spot illumination and collection optics for highly tilted wafer planes are provided. One system configured to collect and detect light scattered from a wafer includes a set of optical elements configured to collect light scattered from spatially separated spots formed on a wafer plane at an oblique angle of incidence and to focus the light to corresponding spatially separated positions in an image plane. This system also includes a detection subsystem configured to separately detect the light focused to the spatially separated positions in the image plane.

Abstract: Methods and systems for monitoring a parameter of a measurement device during polishing, damage to a specimen during polishing, a characteristic of a polishing pad, or a characteristic of a polishing tool are provided. One method includes scanning a specimen with a measurement device during polishing of a specimen to generate output signals at measurement spots on the specimen. The method also includes determining if the output signals are outside of a range of output signals. Output signals outside of the range may indicate that a parameter of the measurement device is out of control limits. In a different embodiment, output signals outside of the range may indicate damage to the specimen. Another method includes scanning a polishing pad with a measurement device to generate output signals at measurement spots on the polishing pad. The method also includes determining a characteristic of the polishing pad from the output signals.