Kla-tencor Technologies Corporation

Ultratech, Inc.

Ultratech Stepper, Inc.

Evan R Mapoles

Christopher F Bevis

David W Shortt

Grace Jing Chen

David Gaines

Michael A Newcomb

Steve Shannon

Tao-Yi Fu

Ralph C Wolf

Grace Hsiu-Ling Chen

A dark field surface inspection tool and system are disclosed herein. The tool includes an illumination source capable of scanning a light beam onto an inspection surface. Light scattered by each inspection point is captured as image data by a photo detector array arranged at a fourier plane. The images captured are adaptively filtered to remove a portion of the bright pixels from the images to generate filtered images. The filtered images are then analyzed to detect defects in the inspection surface. Methods of the invention include using die-to-die comparison to identify bright portions of scattering patterns and generate unique image filters associated with those patterns. The associated images are then filtered to generate filtered images which are then used to detect defects. Also, data models of light scattering behavior can be used to generate filters.

System and method for conducting adaptive fourier filtering to detect defects in dense logic areas of an inspection surface

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. The subtraction is also performed so as to substantially prevent subtracting any actual defect components from the output beam. The apparatus further includes a detector for receiving the output beam and generating an output image or signal based on the output beam.

Dark field inspection apparatus and methods

An integrated inspection system adapted to inspect a substrate. A first inspection station performs a first inspection of the substrate at a first resolution, and identifies defect candidate sites. A controller determines position information associated with each of the identified defect candidate sites. A second inspection station performs a second inspection of the defect candidate sites at a second resolution, where the second resolution is higher than the first resolution. A substrate stage moves the substrate between the first inspection station and the second inspection station, and indexes the substrate under both the first inspection station and the second inspection station.

Inspection tool

A dark field surface inspection tool of the invention includes an illumination source for directing a light beam onto a work piece. The tool includes a scanning element for enabling selected inspection points on the work piece to be scanned by the light beam. During scanning, the light scattered by each inspection point generates light scattering patterns associated with the surface characteristics of the scanned inspection point. The tool includes a photo detector array having photosensitive elements arranged to receive light from the light scattering pattern, thereby capturing an image of the light scattering pattern for each inspection point. Comparison circuitry is included for comparing light scattering patterns with a reference image to enable the identification of defects at the inspection point. The invention also includes a dark field surface inspection method comprising illuminating an inspection surface with a light beam, capturing images of light scattered from the inspection surface and comparing those images with suitable reference images to detect defects in the inspection surface.

Surface inspection system and method for using photo detector array to detect defects in inspection surface

An image stabilization apparatus and method for stabilizing the imaging of a high-performance optical system prone to imaging instabilities from thermal effects. Thermal instabilities within the lens, such as convection, can result in image placement errors in a high-performance optical system. The apparatus includes a heating element arranged on the upper surface of the optical system to provide heat to one or more gas-filled spaces in the optical system. An insulating blanket covers a portion of the optical system to uniformize the heating of the optical system and increase efficiency of the apparatus. The gas in the spaces is heated so that the warmer gases reside near the upper portion of the optical system, while the cooler gases reside near the lower portion of the optical system. This creates a stable thermal environment within the lens system, thereby stabilizing the imaging. Optionally gas can be flowed over the lower surface to keep heat from heating the lower portion of the optical system.

Imaging stabilization apparatus and method for high-performance optical systems

An image stabilization apparatus and method for stabilizing the imaging of a high-performance optical system prone to imaging instabilities from thermal effects. Thermal instabilities within the lens, such as convection, can result in image placement errors in a high-performance optical system. The apparatus includes a heating element arranged on the upper surface of the optical system to provide heat to one or more gas-filled spaces in the optical system. An insulating blanket covers a portion of the optical system to uniformize the heating of the optical system and increase efficiency of the apparatus. The gas in the spaces is heated so that the warmer gases reside near the upper portion of the optical system, while the cooler gases reside near the lower portion of the optical system. This creates a stable thermal environment within the lens system, thereby stabilizing the imaging. Optionally, gas can be flowed over the lower surface to keep heat from heating the lower portion of the optical system.

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San Ramon, CA, United States of America

Evan R Mapoles