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Patent

Automated photomask inspection apparatus

Mark J. Wihl1, Tao-Yi Fu1, Marek Zywno1, Damon F. Kvamme1, Michael E Fein1 
20 Aug 1992-
TL;DR: In this article, an automated photomask inspection apparatus including an XY state (12) for transporting a substrate (14) under test in a serpentine path in an XY plane, an optical system (16) comprising a laser (30), a transmission light detector (34), a reflected light detector(36), optical elements defining reference beam paths and illuminating beam paths between the laser, the substrate and the detectors and an acousto-optical beam scanner (40, 42) for reciprocatingly scanning the illuminating and reference beams relative to the substrate surface, and an electronic control
Abstract: An automated photomask inspection apparatus including an XY state (12) for transporting a substrate (14) under test in a serpentine path in an XY plane, an optical system (16) comprising a laser (30), a transmission light detector (34), a reflected light detector (36), optical elements defining reference beam paths and illuminating beam paths between the laser, the substrate and the detectors and an acousto-optical beam scanner (40, 42) for reciprocatingly scanning the illuminating and reference beams relative to the substrate surface, and an electronic control, analysis and display system for controlling the operation of the stage and optical system and for interpreting and storing the signals output by the detectors. The apparatus can operate in a die-to-die comparison mode or a die-to-database mode.
Citations
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Patent
07 Jul 2005
TL;DR: In this article, a support synthesized with polymer sequences at known locations according to the methods disclosed in U.S. Pat. No. 5,143,854 and PCT WO 92/10092 or others, can be detected by exposing selected regions of sample 1500 to radiation from a source 1100 and detecting the emission therefrom, and repeating the steps of exposition and detection until the sample is completely examined.
Abstract: Labeled targets on a support synthesized with polymer sequences at known locations according to the methods disclosed in U.S. Pat. No. 5,143,854 and PCT WO 92/10092 or others, can be detected by exposing selected regions of sample 1500 to radiation from a source 1100 and detecting the emission therefrom, and repeating the steps of exposition and detection until the sample is completely examined.

795 citations

Patent
David Stern1, Peter Fiekowsky1
17 Sep 2008
TL;DR: In this article, fluorescently marked targets are detected by exposing selected regions of the substrate 230 to light from a light source 100 and detecting the photons from the light fluoresced therefrom, and repeating the steps of exposure and detection until the substrate is completely examined.
Abstract: Fluorescently marked targets bind to a substrate 230 synthesized with polymer sequences at known locations. The targets are detected by exposing selected regions of the substrate 230 to light from a light source 100 and detecting the photons from the light fluoresced therefrom, and repeating the steps of exposure and detection until the substrate 230 is completely examined. The resulting data can be used to determine binding affinity of the targets to specific polymer sequences.

532 citations

Patent
Khurram Zafar1, Sagar A. Kekare1, Ellis Chang1, Allen Park1, Peter Rose1 
20 Nov 2006
TL;DR: In this paper, a computer-implemented method for binning defects detected on a wafer includes comparing portions of design data proximate positions of the defects in design data space.
Abstract: Various methods and systems for utilizing design data in combination with inspection data are provided. One computer-implemented method for binning defects detected on a wafer includes comparing portions of design data proximate positions of the defects in design data space. The method also includes determining if the design data in the portions is at least similar based on results of the comparing step. In addition, the method includes binning the defects in groups such that the portions of the design data proximate the positions of the defects in each of the groups are at least similar. The method further includes storing results of the binning step in a storage medium.

528 citations

Patent
18 Sep 1997
TL;DR: In this article, the phase shift mask and the single phase structure mask are derived from a set of masks used in a larger minimum dimension process technology and used for shrinking integrated circuit designs.
Abstract: A method and apparatus for creating a phase shifting mask and a structure mask for shrinking integrated circuit designs. One embodiment of the invention includes using a two mask process. The first mask is a phase shift mask and the second mask is a single phase structure mask. The phase shift mask primarily defines regions requiring phase shifting. The single phase structure mask primarily defines regions not requiring phase shifting. The single phase structure mask also prevents the erasure of the phase shifting regions and prevents the creation of undesirable artifact regions that would otherwise be created by the phase shift mask. Both masks are derived from a set of masks used in a larger minimum dimension process technology.

347 citations

Patent
17 Sep 1998
TL;DR: In this paper, a method for performing rule checking on OPC corrected or otherwise corrected designs is described, which comprises accessing a corrected design and generating a simulated image, which corresponds to a simulation of an image which would be printed on a wafer if the wafer were exposed to an illumination source directed through the corrected design.
Abstract: A method for performing design rule checking on OPC corrected or otherwise corrected designs is described. This method comprises accessing a corrected design and generating a simulated image. The simulated image corresponds to a simulation of an image which would be printed on a wafer if the wafer were exposed to an illumination source directed through the corrected design. The characteristics of the illumination source are determined by a set of lithography parameters. In creating the image, additional characteristics can be used to simulate portions of the fabrication process. However, what is important is that a resulting simulated image is created. The simulated image can then be used by the design rule checker. Importantly, the simulated image can be processed to reduce the number of vertices in the simulated image, relative to the number of vertices in the OPC corrected design layout. Also, the simulated image can be compared with an idea layout image, the results of which can then be used to reduce the amount of information that is needed to perform the design rule checking.

328 citations

References
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Patent
12 Jun 1991
TL;DR: In this article, the rough surface of an object is estimated by moving the object along a z axis so that a highest point of the rough surfaces is optically aligned with and outside of the focus range of a solid-state imaging array.
Abstract: A method of profiling a rough surface of an object includes moving the object along a z axis so that a highest point of the rough surface is optically aligned with and outside of the focus range of a solid-state imaging array. An interferogram of the rough surface then is produced by means of a two beam interferometer. The solid-state imaging array is operated to scan the rough surface along x and y axes to produce intensity data for each pixel of the solid-state imaging array for a plurality of frames each shifted from the other by a preselected phase difference. The modulation for each pixel is computed from the intensity data. The most recently computed modulation of each pixel is compared with a stored prior value of modulation of that pixel. The prior value is replaced with the most recently computed value if the most recently computed value is greater. The object is incrementally moved a selected distance along the z axis, and the foregoing procedure is repeated until maximum values of modulation and corresponding relative height of the rough surface are obtained and stored for each pixel.

190 citations

Patent
14 Jul 1986
TL;DR: In this article, a photomask and reticle inspection method and apparatus is presented, where a selected surface area of an object is inspected and a first stream of data having signal values representing the image content of each pixel thereof is generated, a second stream of the intended image content representing the pixel of each image of the first stream, corresponding portions of the stored and aligned first and second portions of data are compared to detect difference therebetween, and upon detecting a difference exceeding a predetermined threshold, the presence of a defect at a particular pixel location on the inspected object is indicated.
Abstract: A photomask and reticle inspection method and apparatus wherein a selected surface area of an object is inspected and a first stream of data having signal values representing the image content of each pixel thereof is generated, a second stream of data having signal values representing the intended image content of each pixel of the first stream of data is generated, corresponding portions of the first and second streams of data are stored in memory, any misalignment between the stored portions of the first and second streams of data is detected, the misaligned first and second portions of data are then aligned using shifts of an integral number of pixels and/or subpixel interpolation to correct the detected misalignment therebetween, corresponding subportions of the stored and aligned first and second portions of data are then compared to detect difference therebetween, and upon detecting a difference exceeding a predetermined threshold, the presence of a defect at a particular pixel location on the inspected object is indicated.

186 citations

Patent
05 Oct 1987
TL;DR: In this paper, an automatic inspection system including an illuminator for illuminating a reticle or photomask to be inspected, while optically projecting a magnified image of the reticle/photomask onto a plurality of detector elements.
Abstract: An automatic inspection system including an illuminator for illuminating a reticle or photomask to be inspected, while optically projecting a magnified image of the reticle or photomask onto a plurality of detector elements. A carriage assembly moves the object at a constant velocity to allow the detector elements to sequentially view the entire surface to be inspected. The detector elements are responsive to the intensity of light incident thereupon and are periodically scanned to obtain a two-dimensional measured representation of the object. A database adaptor formulates a two-dimensional representation from the design database description corresponding to the scanned object simultaneously and in synchronism with the scanning of the photomask or reticle. The measured and database adapted representation of the scanned object are input to a signal processor for alignment and defect detection. While the representations are shifted through a memory, an alignment circuit dynamically measures and corrects for misalignment between the representations, so that a defect detector can effectively compare the representations for defects. Additional correction of misalignment between the representations is obtained by modulating the size of the measured representation as detected by the detector elements. At the operator's option, a second measured image of a multi-cell reticle or photomask may be used for comparison as a substitute for the database representation.

172 citations

Patent
03 Apr 1979
TL;DR: Optical inspection apparatus for detecting differences between two dies in a photomask and including a carriage for supporting the objects to be inspected and for simultaneously moving such objects along an inspection path, an illuminator for illuminating corresponding portions of the objects as they are moved along the inspection path as discussed by the authors.
Abstract: Optical inspection apparatus for detecting differences between two dies in a photomask and including a carriage for supporting the objects to be inspected and for simultaneously moving such objects along an inspection path, an illuminator for illuminating corresponding portions of the objects as they are moved along the inspection path, electro-optical detectors for individually inspecting the illuminated portions and for developing first and second electrical signals respectively corresponding thereto, electronic memories for storing the first and second electrical signals, a computer for scanning the memories and for electronically aligning a readout of the first signal relative to a readout of the second signal, and a comparator for comparing the electronically aligned signals and for indicating any differences therebetween.

167 citations

Patent
Shigeo Sakino1, Eiji Osanai1, Mahito Negishi1, Michio Horikoshi1, Mitsuru Inoue1, Kazuya Ono1 
23 Jan 1989
TL;DR: In this paper, two parallel stationary guides are fixed to a surface plate and plural hydrostatic gas or bearing members are provided for the surface plate, while a Y stage is moved in a Y-axis direction under the influence of these bearing members.
Abstract: In a movement guiding device, two parallel stationary guides are fixed to a surface plate and plural hydrostatic gas or bearing members are provided for the surface plate and the stationary guides. A Y stage is moved in a Y-axis direction under the influence of these bearing members. Additional hydrostatic gas or air bearing members are provided in relation to the surface plate and the Y stage so as to support an X stage for movement in an X-axis direction orthogonal to the Y-axis direction. Guide of the Y stage in the X-axis direction is made by the stationary guides on the surface plate, while guide thereof in a Z-axis direction perpendicular to an X-Y plane is made by the surface plate. Guide of the X stage in the Y-axis direction is made by the Y stage, while the guide thereof in the Z-axis direction is made by the surface plate, similar to the Y stage. With such structure, any vibration, rolling, or otherwise, of the Y stage is not transmitted to the X stage. Thus, high-precision guide is attainable. Linear motors are used as drive sources for the X and Y stages, so that all movable portions are provided by non-contact structures. Further, suitable brake members are used, which members are operable at a time of an accident of the stage. By this, accidental collision of the stage and/or derailment of the stage from the guide can be prevented.

151 citations