Apparatus for measuring overlay errors
First Claim
1. A metrology system for determining the overlay between at least two separately generated patterns on a single or successive layers of a substrate, the system comprising:
- an optical assembly for capturing images of a multidirectional overlay mark comprising;
a first region having at least two separately generated working zones, that are juxtaposed relative to one another, and are configured to provide overlay information in a first direction, and each include a periodic structure comprised of a plurality of coarsely segmented elements positioned therein,a second region having at least two separately generated working zones, that are juxtaposed relative to one another, and are configured to provide overlay information in the first direction, and each include a periodic structure comprised of a plurality of coarsely segmented elements positioned therein,a third region having at least two separately generated working zones, that are juxtaposed relative to one another, and are configured to provide overlay information in a second direction that differs from the first direction, and each include a periodic structure comprised of a plurality of coarsely segmented elements positioned therein,a fourth region having at least two separately generated working zones, that are juxtaposed relative to one another, and are configured to provide overlay information in the second direction, and each include a periodic structure comprised of a plurality of coarsely segmented elements positioned therein,wherein the working zones of the first and second regions that were generated together are diagonally opposed and spatially offset relative to one another, andwherein the working zones of the third and fourth regions that were generated together are diagonally opposed and spatially offset relative to one another; and
a computer for analyzing the captured images to determine whether the multidirectional overlay mark has an overlay error.
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Abstract
A metrology system for determining overlay is disclosed. The system includes an optical assembly for capturing images of an overlay mark and a computer for analyzing the captured images to determine whether there is an overlay error. The mark comprises first and second regions that each include at least two separately generated working zones, juxtaposed relative to one another, configured to provide overlay information in a first direction, and include a periodic structure having coarsely segmented elements. The mark comprises third and fourth regions that each include at least two separately generated working zones, juxtaposed relative to one another, configured to provide overlay information in a second direction, and include a periodic structure having coarsely segmented elements. Working zones of the first and second regions are diagonally opposed and spatially offset relative to one another, and the working zones of the third and fourth regions are diagonally opposed and spatially offset relative to one another.
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Citations
64 Claims
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1. A metrology system for determining the overlay between at least two separately generated patterns on a single or successive layers of a substrate, the system comprising:
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an optical assembly for capturing images of a multidirectional overlay mark comprising; a first region having at least two separately generated working zones, that are juxtaposed relative to one another, and are configured to provide overlay information in a first direction, and each include a periodic structure comprised of a plurality of coarsely segmented elements positioned therein, a second region having at least two separately generated working zones, that are juxtaposed relative to one another, and are configured to provide overlay information in the first direction, and each include a periodic structure comprised of a plurality of coarsely segmented elements positioned therein, a third region having at least two separately generated working zones, that are juxtaposed relative to one another, and are configured to provide overlay information in a second direction that differs from the first direction, and each include a periodic structure comprised of a plurality of coarsely segmented elements positioned therein, a fourth region having at least two separately generated working zones, that are juxtaposed relative to one another, and are configured to provide overlay information in the second direction, and each include a periodic structure comprised of a plurality of coarsely segmented elements positioned therein, wherein the working zones of the first and second regions that were generated together are diagonally opposed and spatially offset relative to one another, and wherein the working zones of the third and fourth regions that were generated together are diagonally opposed and spatially offset relative to one another; and a computer for analyzing the captured images to determine whether the multidirectional overlay mark has an overlay error. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A metrology system for determining the overlay between at least two separately generated patterns on a single or successive layers of a substrate, the system comprising:
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an optical assembly for capturing images of an overlay mark comprising; a first set of working zones being formed from a first process and having at least two working zones that are diagonally opposed and spatially offset relative to each other, each of the first set of working zones including a periodic structure comprising a plurality of coarsely segmented elements that are each formed from a plurality of finely segmented elements that are evenly divided over the entire coarsely segmented elements of the first set of working zones, and a second set of working zones being formed from a second process and having at least two working zones that are diagonally opposed and spatially offset relative to each other, each of the second set of working zones including a periodic structure comprising a plurality of coarsely segmented elements that are each formed from a plurality of finely segmented elements that are evenly divided over the entire coarsely segmented elements of the second set of working zones; and a computer for analyzing the captured images to determine whether the overlay mark has an overlay error. - View Dependent Claims (13, 14, 15)
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16. A metrology system for determining the overlay between at least two separately generated patterns on a single or successive layers of a substrate, the system comprising:
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an optical assembly for capturing images of a multidirectional overlay mark comprising; a plurality of first periodic structures formed via a first process and having a first orientation and comprised of a plurality of coarsely segmented elements, wherein the first periodic structures comprise at least two working zones that are diagonally opposed and spatially offset relative to each other; a plurality of second periodic structures formed via a second process and having the first orientation and comprised of a plurality of coarsely segmented elements, wherein the second periodic structures comprise at least two working zones that are diagonally opposed and spatially offset relative to each other; a plurality of third periodic structures formed via the first process and having a second orientation and comprised of a plurality of coarsely segmented elements, wherein the third periodic structures comprise at least two working zones that are diagonally opposed and spatially offset relative to each other; and a plurality of fourth periodic structures formed via the second process and having the second orientation and comprised of a plurality of coarsely segmented elements, wherein the fourth periodic structures comprise at least two working zones that are diagonally opposed and spatially offset relative to each other, wherein each of the working zones of the first plurality of periodic structures is adjacent to one of the working zones of the second plurality of periodic structures, and wherein each of the working zones of the third plurality of periodic structures is adjacent to one of the working zones of the fourth plurality of periodic structures; and a computer for analyzing the captured images to determine whether the multidirectional overlay mark has an overlay error. - View Dependent Claims (17, 18, 19, 20)
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21. A metrology system for determining the overlay between at least two separately generated patterns on a single or successive layers of a substrate, the system comprising:
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an optical assembly for capturing images of a multidirectional overlay mark comprising; a first set of working zones being formed from a first process, and each first set of working zones including a periodic structure of a plurality of elements that are spaced apart within a plurality of lines and configured to convey overlay information in a first direction and a second direction that differs from the first direction; and a second set of working zones being formed from a second process, and each second set of working zones including a periodic structure of a plurality of elements that are spaced apart within a plurality of lines and configured to convey overlay information in the first direction and the second direction, wherein the first set, of working zones and second set of working zones are diagonally opposed and spatially offset relative to one another, and wherein the elements are substantially distributed over an area of the overlay mark; and a computer for analyzing the captured images to determine whether the multidirectional overlay mark has an overlay error. - View Dependent Claims (22, 23, 24, 25, 26)
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27. A metrology system for determining the overlay between at least two separately generated patterns on a single or successive layers of a substrate, the system comprising:
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an optical assembly for capturing images of a multidirectional overlay mark comprising; a first quadrant having only two separately generated working zones, that are juxtaposed relative to one another, and are configured to provide overlay information in a first direction, and each include a periodic structure comprised of a plurality of coarsely segmented elements positioned therein, and that together substantially fill their quadrant, a second quadrant having only two separately generated working zones, that are juxtaposed relative to one another, and are configured to provide overlay information in the first direction, and each include a periodic structure comprised of a plurality of coarsely segmented elements positioned therein, and that together substantially fill their quadrant, a third quadrant having only two separately generated working zones, that are juxtaposed relative to one another, and are configured to provide overlay information in a second direction that differs from the first direction, and each include a periodic structure comprised of a plurality of coarsely segmented elements positioned therein, and that together substantially fill their quadrant, and a fourth quadrant having only two separately generated working zones, that are juxtaposed relative to one another, and are configured to provide overlay information in the second direction, and each include a periodic structure comprised of a plurality of coarsely segmented elements positioned therein, and that together substantially fill their quadrant, wherein each quadrant includes an inner working zone and an outer working zone, the inner working zone being positioned towards the center of the multidirectional overlay mark, the outer working zone being positioned toward the periphery of the multidirectional overlay mark, wherein the coarsely segmented elements are finely segmented in order to control the contrast of the resultant image in the metrology system; and a computer for analyzing the captured images to determine whether the multidirectional mark has an overlay error.
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28. A metrology system for determining the overlay between at least two separately generated patterns on a single or successive layers of a substrate, the system comprising:
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an optical assembly for capturing images of an overlay mark that is separated into four quadrants, each of the four quadrants including only two separately generated working zones that together substantially fill their quadrant, each of the working zones including a periodic structure comprised of a plurality of coarsely segmented elements positioned therein, the two separately generated working zones being juxtaposed relative to one another, and configured to provide overlay information in the same direction, each quadrant including an inner working zone and an outer working zone, the inner working zone being positioned towards the center of the overlay mark, the outer working zone being positioned towards the periphery of the overlay mark; and a computer for analyzing the captured images to determine whether the overlay mark has an overlay error. - View Dependent Claims (29, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51)
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31. The system as recited in claim rein the working zones are configured to diminish an impact of non-uniformities across the overlay mark on tool and wafer induced shifts.
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52. A metrology system for determining the overlay between at least two separately generated patterns on a single or successive layers of a substrate, the system comprising:
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an optical assembly for capturing images of an overlay mark that is separated into four quadrants, each of the four quadrants including at least four working zones that together substantially fill their quadrant, each quadrant including a first and second set of working zones and wherein the first set of the working zones are configured to provide overlay in a first direction, and a second set of working zones are configured to provide overlay information in a second direction, the first set of working zones being diagonally opposed with one another, the second set of working zones being diagonally opposed with one another and lying crosswise relative the first set of working zones, each of the working zones including a periodic structure comprised of a plurality of coarsely segmented elements positioned therein; and a computer for analyzing the captured images to determine whether the overlay mark has an overlay error. - View Dependent Claims (53, 54, 55, 56, 57, 58, 59, 60)
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61. A metrology system for determining the overlay between at least two separately generated patterns on a single or successive layers of a substrate, the system comprising:
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an optical assembly for capturing images of a multidirectional overlay mark that is separated into four quadrants, each of the four quadrants including at least three separately generated working zones that are juxtaposed relative to one another and that together substantially fill the quadrant, the upper left quadrant including working zones configured to provide overlay information in a first direction, the upper right quadrant including working zones configured to provide overlay information in a second direction that is different than the first direction, the lower right quadrant including working zones configured to provide overlay information in the first direction, and the lower left quadrant including working zones configured to provide overlay information in the second direction, each of the working zones including a periodic structure comprised of a plurality of coarsely segmented elements positioned therein; and a computer for analyzing the captured images to determine whether the multidirectional overlay mark has an overlay error. - View Dependent Claims (62, 63, 64)
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Specification