VISUAL INSPECTION AND VERIFICATION SYSTEM
First Claim
1. A method of inspecting a mask used in lithography for defects, the method comprising:
- providing a defect area image as a first input, wherein said defect area image comprises an image of a portion of said mask;
providing a first set of lithography parameters as a second input; and
generating a first simulated image in response to said first input, wherein said first simulated image comprises a simulation of an image which would be printed on a wafer if said wafer were exposed to an illumination source directed through said portion of said mask, wherein the characteristics of said illumination source comprise said first set of lithography parameters.
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Accused Products
Abstract
A method and apparatus for inspecting a photolithography mask for defects is provided. The inspection method comprises providing a defect area image to an image simulator wherein the defect area image is an image of a portion of a photolithography mask, and providing a set of lithography parameters as a second input to the image simulator. The defect area image may be provided by an inspection tool which scans the photolithography mask for defects using a high resolution microscope and captures images of areas of the mask around identified potential defects. The image simulator generates a first simulated image in response to the defect area image and the set of lithography parameters. The first simulated image is a simulation of an image which would be printed on a wafer if the wafer were to be exposed to an illumination source directed through the portion of the mask. The method may also include providing a second simulated image which is a simulation of the wafer print of the portion of the design mask which corresponds to the portion represented by the defect area image. The method also provides for the comparison of the first and second simulated images in order to determine the printability of any identified potential defects on the photolithography mask. A method of determining the process window effect of any identified potential defects is also provided for.
150 Citations
90 Claims
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1. A method of inspecting a mask used in lithography for defects, the method comprising:
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providing a defect area image as a first input, wherein said defect area image comprises an image of a portion of said mask;
providing a first set of lithography parameters as a second input; and
generating a first simulated image in response to said first input, wherein said first simulated image comprises a simulation of an image which would be printed on a wafer if said wafer were exposed to an illumination source directed through said portion of said mask, wherein the characteristics of said illumination source comprise said first set of lithography parameters. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43)
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14. The method of inspecting a mask used in lithography for defects of claim 111 comprising:
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providing a set of etching process parameters as a fourth input; and
generating a third simulated image in response to said fourth input, wherein said third simulated image comprises a simulation of an image which would be transferred on said wafer if said wafer were etched in accordance with said etching process parameters after said exposure to said illumination source.
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36. A program storage device readable by a machine, tangibly embodying a program of instructions executable by said machine to perform method steps to inspect a mask used in lithography, the method comprising:
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receiving a defect area image as a first input, wherein said defect area image comprises an image of a portion of said mask;
receiving a first set of lithography parameters as a second input; and
generating a first simulated image in response to said first input, wherein said first simulated image comprises a simulation of an image which would be printed on a wafer if said wafer were exposed to an illumination source directed through said portion of said mask, wherein the characteristics of said illumination source comprise said first set of lithography conditions.
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44. A method of inspecting a mask used in lithography for defects, the method comprising:
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providing a mask inspection tool;
providing a set of potential defect criteria to the mask inspection tool;
scanning said mask with said mask inspection tool for features whose characteristics fall within said set of potential defect criteria;
generating a defect area image as a first input, wherein said defect area image comprises an image of a portion of said mask which contains a potential defect;
providing a first set of lithography parameters as a second input; and
generating a first simulated image with said simulator apparatus in response to said first input, wherein said first simulated image comprises a simulation of an image which would be printed on a wafer if said wafer were exposed to an illumination source directed through said portion of said mask, wherein the characteristics of said illumination source comprise said first set of lithography conditions. - View Dependent Claims (45, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 72, 73, 74, 75, 76, 77, 78, 79, 80)
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46. An apparatus for inspecting a mask used in lithography for defects, the apparatus comprising:
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a resource for receiving a defect area image as a first input, wherein said defect area image comprises an image of a portion of said mask;
a resource for receiving a first set of lithography parameters as a second input; and
an image simulator that generates a first simulated image in response to said first input, wherein said first simulated image comprises a simulation of an image which would be printed on a wafer if said wafer were exposed to an illumination source directed through said portion of said mask, wherein the characteristics of said illumination source comprise said first set of lithography conditions.
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62. The apparatus for inspecting a mask used in lithography for defects of claim comprising:
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a resource for receiving a reference description of said portion of said mask; and
a resource for providing a reference image, wherein said reference image comprises a representation of an image that would be printed on a wafer if said wafer were exposed to an illumination source directed through a second mask, wherein the characteristics of said illumination source comprise said first set of lithography conditions, and wherein said second mask comprises a mask described by said reference description. - View Dependent Claims (63, 64, 65, 66, 67, 68, 69, 70, 71)
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81. A computer program product, comprising:
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a computer usable medium having a computer readable program code embodied therein for causing a computer to inspect a mask used in lithography for defects, the computer readable program code comprising;
computer readable program code that reads a defect area image of a portion of said mask as a first input;
computer readable program code that reads a first set of lithography parameters as a second input; and
computer readable program code that generates a first simulated image in response to said first input, wherein said first simulated image comprises a simulation of an image which would be printed on a wafer if said wafer were exposed to an illumination source directed through said portion of said mask, wherein the characteristics of said illumination source comprise said first set of lithography conditions. - View Dependent Claims (82, 83, 84, 85, 86, 87, 88, 90)
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89. An apparatus for inspecting a mask used in lithography for defects, the apparatus comprising:
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an inspection tool, wherein said inspection tool locates a portion of said mask which contains a potential defect and generates a defect area image, wherein said defect area image comprises an image of said portion of said mask which contains said potential defect;
a resource for receiving said defect area image as a first input;
a resource for receiving a first set of lithography parameters as a second input; and
an image simulator that generates a first simulated image in response to said first input, wherein said first simulated image comprises a simulation of an image which would be printed on a wafer if said wafer were exposed to an illumination source directed through said portion of said mask, wherein the characteristics of said illumination source comprise said first set of lithography conditions.
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Specification