Spot grid array electron imaging system
First Claim
1. An imager comprising:
- an electron beam generator for simultaneously irradiating an array of spots spaced apart from each other on a surface of an object to be imaged;
a detector for collecting signals resulting from the interaction of the spots with the surface of the object to form an image of the irradiated portions of the object surface; and
a movable stage for supporting the object and moving the object such that a predetermined portion of the surface of the object can be irradiated and imaged.
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Accused Products
Abstract
A high data-rate electron beam spot-grid array imaging system is provided that overcomes the low resolution and severe linearity requirements of prior art systems. Embodiments include an imaging system comprising an electron beam generator for simultaneously irradiating an array of spots spaced apart from each other on a surface of an object to be imaged, and a detector for collecting backscattered and/or secondary electrons emitted as a result of the interaction of the spots with the surface of the object to form an image of the irradiated portions of the object surface. A mechanical system moves the substrate in a direction which is nearly parallel to an axis of the array of spots such that as the substrate is moved across the spot array in the scan direction (the y-direction) the spots trace a path which leaves no gaps in the mechanical cross-scan direction (the x-direction). A compensator, such as a servo or a movable mirror, compensates for mechanical inaccuracies in the moving stage, thereby increasing imaging accuracy. In other embodiments, multiple detectors placed at different angles to the substrate collect electrons to provide multiple perspective imaging of the substrate surface.
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Citations
44 Claims
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1. An imager comprising:
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an electron beam generator for simultaneously irradiating an array of spots spaced apart from each other on a surface of an object to be imaged;
a detector for collecting signals resulting from the interaction of the spots with the surface of the object to form an image of the irradiated portions of the object surface; and
a movable stage for supporting the object and moving the object such that a predetermined portion of the surface of the object can be irradiated and imaged. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 43, 44)
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28. An inspection system comprising:
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a first electron beam generator for irradiating a first array of spots spaced apart from each other on a surface of a first object to be imaged;
a second electron beam generator for irradiating a second array of spots spaced apart from each other on a surface of a second object to be imaged, wherein the first and second spot arrays are substantially identical, and the surfaces of the first and second objects correspond to each other;
a first detector array for collecting signals resulting from the interaction of the spots with the surface of the first object to form an image of the irradiated portions of the first object surface;
a second detector array for collecting signals resulting from the interaction of the spots with the surface of the second object to form an image of the irradiated portions of the second object surface;
a movable stage for supporting the first and second objects and moving the objects such that substantially the entire surface of each object can be irradiated and imaged; and
a processor for comparing the images of the first and second objects. - View Dependent Claims (29, 30, 31)
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32. A method comprising the steps of:
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directing electrons to simultaneously irradiate an array of spots spaced apart from each other on a surface of an object to be imaged;
collecting signals resulting from the interaction of the spots with the surface of the object to form an image of the irradiated portions of the object surface; and
moving the object on a movable stage while the irradiating and collecting steps are being performed, such that a predetermined portion of the surface of the object can be irradiated and imaged. - View Dependent Claims (33, 34, 35, 36, 37)
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38. A method comprising:
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directing electrons to simultaneously irradiate a first array of spots spaced apart from each other on a surface of a first object to be imaged;
directing electrons to simultaneously irradiate a second array of spots spaced apart from each other on a surface of a second object to be imaged, wherein the first and second spot arrays are substantially identical, and the surfaces of the first and second objects correspond to each other;
collecting signals resulting from the interaction of the spots with the surface of the first object to form an image of the irradiated portions of the first object surface;
collecting signals resulting from the interaction of the spots with the surface of the second object to form an image of the irradiated portions of the second object surface;
moving the first and second objects on a movable stage such that a predetermined portion of the surface of each object can be irradiated and imaged; and
comparing the images of the first and second objects. - View Dependent Claims (39, 40, 41, 42)
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Specification