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: 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: Various inspection and review systems for wafers or reticles are provided. One system includes an optical component configured to project light onto a specimen during inspection or review. The system also includes a liquid disposed between and in contact with surfaces of the optical component and the specimen. The liquid does not permanently alter properties of the optical component or the specimen. Preferably, the presence of the liquid between the optical component and the specimen increases the resolution of the inspection or review system. Another system includes an inspection or review subsystem configured to project light through an optical component, a liquid, and onto a specimen. The liquid contacts the optical component and the specimen. This system also includes a processing subsystem configured to remove the liquid from the specimen after inspection or review. In some embodiments, the processing subsystem is configured to clean the specimen after inspection or review.

Abstract: A method for limiting exposure of a substrate to potentially damaging radiation from a radiating apparatus. A database of information associated with the substrate is compiled, and the substrate is identified prior to processing the substrate on the radiating apparatus. The database of information associated with the substrate is accessed, including its past irradiation history of dosage and type of irradiation, based on the substrate identification, and the operation of the radiating apparatus is selectively modified based at least in part on the information associated with the substrate.

Abstract: An illuminator for uniformly illuminating an entrance pupil of an inspection system in order to increase inspection resolution and sensitivity and improve system-to-system matching is described. The illuminator incorporates at least two lightpipes for spatially and angularly distributing light rays from the illuminator uniformly across the entrance pupil. The illuminator also results in spatial and angular uniformity at the field stop plane. In one embodiment, one lightpipe has a circular shape and a second lightpipe has a rectangular shape.

Abstract: Techniques for utilizing a microscope inspection system capable of inspecting specimens at high throughput rates are described. The inspection system achieves the higher throughput rates by utilizing more than one detector array and a large field of view to scan the surface of the semiconductor wafers. The microscope inspection system also has high magnification capabilities, a high numerical aperture, and a large field of view. By using more than one detector array, more surface area of a wafer can be inspected during each scanning swath across the semiconductor wafers. The microscope inspection system is configured to have a larger field of view so that the multiple detector arrays can be properly utilized. Additionally, special arrangements of reflective and/or refractive surfaces are used in order to fit the detector arrays within the physical constraints of the inspection system.

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: A method for inspecting semiconductor wafers is provided in which a plurality of independent, low-cost, optical-inspection subsystems are packaged and integrated to simultaneously perform parallel inspections of portions of the wafer, the wafer location relative to the inspection being controlled so that the entire wafer is imaged by the system of optical subsystems in a raster-scan mode. A monochromatic coherent-light source illuminates the wafer surface. A darkfield-optical system collects scattered light and filters patterns produced by valid periodic wafer structures using Fourier filtered. The filtered light is processed by general purpose digital-signal processors. Image subtraction methods are used to detect wafer defects, which are reported to a main computer to aid in statistical process control, particularly for manufacturing equipment.

Abstract: The present invention pertains to techniques for increasing the available illumination light, increasing the resolution, and optimizing the spectrum of optical inspection systems. These techniques involve combining the light beams from two or more separate illumination sources. In one embodiment, this performed by utilizing two separate illumination sources wherein one of the illumination sources compensates the other illumination source in the wavelength range where illumination light intensity is low. Specifically, this can be performed by utilizing a broadband illumination source and a narrowband illumination source combined with dichroic beamsplitters.

Abstract: Techniques for utilizing a microscope inspection system capable of inspecting specimens at high throughput rates are described. The inspection system achieves the higher throughput rates by utilizing more than one detector array and a large field of view to scan the surface of the semiconductor wafers. The microscope inspection system also has high magnification capabilities, a high numerical aperture, and a large field of view. By using more than one detector array, more surface area of a wafer can be inspected during each scanning swath across the semiconductor wafers. The microscope inspection system is configured to have a larger field of view so that the multiple detector arrays can be properly utilized. Additionally, special arrangements of reflective and/or refractive surfaces are used in order to fit the detector arrays within the physical constraints of the inspection system.

Abstract: The present invention pertains to techniques for increasing the available illumination light, increasing the resolution, and optimizing the spectrum of optical inspection systems. These techniques involve combining the light beams from two or more separate illumination sources. In one embodiment, this performed by utilizing two separate illumination sources wherein one of the illumination sources compensates the other illumination source in the wavelength range where illumination light intensity is low. Specifically, this can be performed by utilizing a broadband illumination source and a narrowband illumination source combined with dichroic beamsplitters.

Abstract: The present invention pertains to an optical inspection system capable of obtaining very high signal-to-noise ratio data and that is capable of high speed scanning rates. The ability to obtain high signal-to-noise data is obtained by selecting parts of the scattering hemisphere where signal from a defect is high and noise due to scattering from wafers structures is low. One embodiment of the optical inspection system includes a set of lenses used to form an image of the inspected specimen at a Fourier plane with telecentric-in-object space imaging. Another embodiment of the optical inspection system includes a substantially hemispherical shaped mirror system that provides a large collection numerical aperture that allows for the collection of substantially all of the hemisphere of scattered light from an inspected specimen. The present invention also discloses techniques for enhancing the signal-to-noise ratio of image data received from the optical inspection system.

Abstract: Disclosed are methods and apparatus for designing an optical spectrum of an illumination light beam within an optical inspection system. A set of conditions for inspecting a film on a sample by directing an illumination light beam at the sample is determined. At least a portion of the illumination light beam is reflected off the sample and used to generate an image of at least a portion of the film on the sample. A plurality of peak wavelength values are determined for the optical spectrum of the illumination light beam so as to control color variation in the image of the film portion. The determination of the peak wavelengths is based on the determined set of conditions and a selected thickness range of the film. In one specific embodiment, the color variation is reduced, while in another embodiment the color variation is increased to enhance pattern contrast. An apparatus which implements the designed optical spectrum is also disclosed.

Abstract: Disclosed are methods and apparatus for designing an optical spectrum of an illumination light beam within an optical inspection system. A set of conditions for inspecting a film on a sample by directing an illumination light beam at the sample is determined. At least a portion of the illumination light beam is reflected off the sample and used to generate an image of at least a portion of the film on the sample. A plurality of peak wavelength values are determined for the optical spectrum of the illumination light beam so as to control color variation in the image of the film portion. The determination of the peak wavelengths is based on the determined set of conditions and a selected thickness range of the film. In one specific embodiment, the color variation is reduced, while in another embodiment the color variation is increased to enhance pattern contrast. An apparatus which implements the designed optical spectrum is also disclosed.

Abstract: The present invention pertains to an optical inspection system capable of obtaining very high signal-to-noise ratio data and that is capable of high speed scanning rates. The ability to obtain high signal-to-noise data is obtained by selecting parts of the scattering hemisphere where signal from a defect is high and noise due to scattering from wafers structures is low. One embodiment of the optical inspection system includes a set of lenses used to form an image of the inspected specimen at a Fourier plane with telecentric-in-object space imaging. Another embodiment of the optical inspection system includes a substantially hemispherical shaped mirror system that provides a large collection numerical aperture that allows for the collection of substantially all of the hemisphere of scattered light from an inspected specimen. The present invention also discloses techniques for enhancing the signal-to-noise ratio of image data received from the optical inspection system.

Abstract: A method for inspecting semiconductor wafers is provided in which a plurality of independent, low-cost, optical-inspection subsystems are packaged and integrated to simultaneously perform parallel inspections of portions of the wafer, the wafer location relative to the inspection being controlled so that the entire wafer is imaged by the system of optical subsystems in a raster-scan mode. A monochromatic coherent-light source illuminates the wafer surface. A darkfield-optical system collects scattered light and filters patterns produced by valid periodic wafer structures using Fourier filtering. The filtered light is processed by general purpose digital-signal processors. Image subtraction methods are used to detect wafer defects, which are reported to a main computer to aid in statistical process control, particularly for manufacturing equipment.

Abstract: A thin, flexible, reflecting diffuse material is placed or formed on an anterior surface of a cornea. The material has properties that precisely conform to changes in shape of the cornea. This allows remote sensing of the shape of the cornea by projected fringe contouring.

Abstract: A system for aligning a test beam of an infrared interferometer with a reference beam thereof includes a phosphor screen positioned in a common path of the interferometer at a focal point of a lens in the path. The phosphor screen is illuminated with ultraviolet light to stimulate an area of the phosphor screen to emit visible light. Infrared laser light from the test beam is focused onto a spot of the phosphor screen. The infrared laser light acts on the spot to prevent the phosphor screen from emitting visible light from the spot and hence the position where the laser beam strikes the phosphor screen appears dark. Visible light emitted by the phosphor screen is focused into a visible light camera, and an image of visible light emitted by the phosphor screen is produced on a video monitor. The dark spot on the phosphor screen appears as an image spot on the video monitor. The test beam is adjusted to move the image spot to a predetermined location of the video monitor representing an aligned condition.

Abstract: A phase shifting projector includes an incandescent lamp, a heat-absorbing filter filtering infrared light from the incandescent lamp, a condensing lens receiving light from the filter, a transparent slide having a sinusoidal grating thereon, a projecting lens, a rotatable transparent plate disposed between the slide and the projecting lens, a test surface on which the grating is projected, and a stepper motor connected to the transparent plate for rotating it about an axis generally parallel to a line of the grating to modulate the phase of the grating image projected on the test surface.

Abstract: This invention is directed to a synthetic fireplace log with a hollow core, said log being composed of shredded paper and wax. The logs are produced by continuously compacting shredded paper into one end of a compaction chamber, injecting hot molten wax into the compacted paper in the compaction chamber, cooling and hardening the wax, and continuously extruding finished logs from the opposite end of the compaction chamber with means for cutting the continuously extruded log into convenient lengths.