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US 8,785,112 B2Granted
Reticle defect correction by second exposure
AssigneeGLOBAL FOUNDRIES Inc.
InventorArthur Hotzel
Life of this patent
Estimating the term…
Abstract
Correction of reticle defects, such as EUV reticle defects, is accomplished with a second exposure. Embodiments include obtaining a reticle with a first pattern corresponding to a design for a wafer pattern, detecting dark defects and/or design/OPC weak spots in the first pattern, exposing a resist covered wafer using the reticle, and exposing the wafer using a second reticle with a second pattern or a second image field with openings corresponding to the dark defects, with a repair pattern on the reticle or on another reticle, or with a programmed e-beam or laser writer.
Claims13
A method comprising:
- obtaining a first reticle with a first pattern corresponding to a design for a wafer pattern;
- detecting dark defects and/or design/OPC weak spots in the first pattern;
- obtaining a second reticle with a second pattern, the second pattern being dark except for openings corresponding to the dark defects and/or design/OPC weak spots in the first pattern, or forming a second pattern of openings on the first reticle, in a region outside the first pattern, the openings corresponding to the dark defects and/or design/OPC weak spots in the first pattern;
- exposing a resist covered wafer using the first and second patterns;
- including alignment marks and/or overlay marks and/or metrology structures on the second reticle or in the second pattern on the first reticle;
- providing matching overlay marks in the first pattern or on another reticle used for patterning a layer on the wafer prior to or subsequent to exposing the resist covered wafer using the first and second patterns;
- leaving dark areas in the first pattern at the positions corresponding to the metrology structures;
- and
- aligning the openings of the second pattern with the defects and/or design/OPC weak spots of the first pattern using the alignment marks;
- and/or measuring the structures corresponding to the overlay marks and/or metrology structures which are formed on the wafer after the exposures and development of the resist, thereby monitoring the process of the exposure with the second pattern.
7 more elements
A method comprising:
- obtaining a first reticle with a first pattern corresponding to a design for a wafer pattern;
- detecting dark defects and/or design/OPC weak spots in the first pattern;
- forming repair patterns on the first reticle, in the region outside the first pattern, or on a second reticle;
- selecting the best matching repair pattern for each defect and/or design/OPC weak spot in the first pattern;
- exposing a resist covered wafer using the first pattern;
- and
- exposing portions of the wafer corresponding to the dark defects and/or design/OPC weak spots using the repair patterns.
4 more elements
Dependencies are inferred from the claim text.