Exposure Method and Lithography System
First Claim
1. An exposure method in which overlay exposure to a photosensitive object is performed by overlaying layers, the method including:
- a selection process in which a reference layer that serves as a reference to obtain information on overlay exposure of a next layer is selected for each of axes of a two-dimensional orthogonal coordinate system that serves as a reference on overlay, from among at least two layers that have been already exposed, whereinthe information on overlay exposure includes a distortion component of a projected image at the point in time when exposure of the reference layer was performed, in a projection exposure apparatus that was used for the exposure of the reference layer.
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Accused Products
Abstract
In the case where the previous process (X) and the previous process (Y) are different in step 310, only a distortion amount in an X-axis direction is extracted from image distortion data of the previous process (X) in Step 316 and only a distortion amount in a Y-axis direction is extracted from image distortion data of the previous process (Y) in Step 318, and then in Step 320, image distortion data is created by synthesizing the extracted distortion amounts, and the synthesized image distortion data is used for subsequent adjustment of projected images. With this operation, the distortion of projected images can be adjusted per axis and accordingly overlay exposure with high accuracy can be realized.
23 Citations
16 Claims
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1. An exposure method in which overlay exposure to a photosensitive object is performed by overlaying layers, the method including:
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a selection process in which a reference layer that serves as a reference to obtain information on overlay exposure of a next layer is selected for each of axes of a two-dimensional orthogonal coordinate system that serves as a reference on overlay, from among at least two layers that have been already exposed, wherein the information on overlay exposure includes a distortion component of a projected image at the point in time when exposure of the reference layer was performed, in a projection exposure apparatus that was used for the exposure of the reference layer. - View Dependent Claims (2, 3, 4)
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5. An exposure method in which overlay exposure to a photosensitive object is performed by overlaying layers, the method including:
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a selection process in which a reference layer that serves as a reference to obtain information on overlay exposure of a next layer is selected for each of axes of a two-dimensional orthogonal coordinate system that serves as a reference on overlay, from among at least two layers that have been already exposed, wherein the information on overlay exposure includes a nonlinear component of a positional deviation amount of formation positions of a plurality of divided areas with respect to positions, which serve as datum positions when the plurality of divided areas are formed on the photosensitive object, in a projection exposure apparatus that was used for exposure of the reference layer. - View Dependent Claims (6, 7, 8)
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9. A lithography system that performs overlay exposure to a photosensitive object by overlaying layers, the system comprising:
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a plurality of projection exposure apparatuses; a storage unit that stores information on a formation state of a pattern image of a layer that has been already exposed by any one of the plurality of projection exposure apparatuses; a first selection unit that selects a reference layer that serves as a reference to obtain information on overlay exposure of a next layer for each of axes of a two-dimensional orthogonal coordinate system that serves as a reference on overlay, from among at least two layers that have been already exposed, the information on overlay exposure including a distortion component of a projected image at the point in time when exposure of the reference layer was performed, in a projection exposure apparatus that was used for the exposure of the reference layer; a second selection unit that selects a projection exposure apparatus that performs overlay exposure of a next layer from among the plurality of projection exposure apparatuses; and a computation unit that computes information on overlay exposure of a next layer in the selected projection exposure apparatus based on information on an exposure state of the selected reference layer for each of the axes. - View Dependent Claims (10, 11, 12)
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13. A lithography system that performs overlay exposure to a photosensitive object by overlaying layers, the system comprising:
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a plurality of projection exposure apparatuses; a storage unit that stores information on a formation state of a pattern image of a layer that has been already exposed by any one of the plurality of projection exposure apparatuses; a first selection unit that selects a reference layer that serves as a reference to obtain information on overlay exposure of a next layer for each of axes of a two-dimensional orthogonal coordinate system that serves as a reference on overlay, from among at least two layers that have been already exposed, the information on overlay exposure including a nonlinear component of a positional deviation amount of formation positions of a plurality of divided areas with respect to positions, which serve as datum positions when the plurality of divided areas are formed on the photosensitive object, in a projection exposure apparatus that was used for overlay exposure of the reference layer; a second selection unit that selects a projection exposure apparatus that performs overlay exposure of a next layer from among the plurality of projection exposure apparatuses; and a computation unit that computes information on overlay exposure of a next layer in the selected projection exposure apparatus based on information on an exposure state of the selected reference layer for each of the axes. - View Dependent Claims (14, 15, 16)
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Specification