Reticle defect correction by second exposure
AssigneeGlobalfoundries Inc.
InventorArthur Hotzel
Life of this patent
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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.
Claims20
A method comprising:
- obtaining a reticle;
- detecting dark defects and/or design/OPC weak spots on the reticle;
- programming an e-beam or laser writer to expose a wafer in regions corresponding to the dark defects and/or design/OPC weak spots on the reticle;
- and
- exposing the wafer, covered with a resist, with the reticle and with the programmed e-beam or laser writer.
A method comprising:
- obtaining a reticle;
- detecting clear defects and dark defects and/or design/OPC weak spots on the reticle;
- repairing some of the detected defects;
- converting remaining clear defects to additional dark defects;
- characterizing remaining dark defects and additional dark defects;
- determining a suitable correction shape and dose based on the characterized defects;
- programming an e-beam or laser writer to expose a wafer in regions corresponding to the additional dark defects and the remaining dark defects with the suitable correction shape and dose and/or to expose the wafer in regions corresponding to the design/OPC weak spots on the reticle;
- and
- exposing the wafer, covered with a resist, with the reticle and with the programmed e-beam or laser writer.
A method comprising:
- obtaining a reticle;
- detecting clear defects and dark defects and/or design/OPC weak spots on the reticle;
- repairing some of the detected defects;
- converting remaining clear defects to additional dark defects;
- characterizing remaining dark defects and additional dark defects;
- determining a suitable correction shape and dose based on the characterized defects;
- programming an e-beam or laser writer to write overlay marks and/or metrology structures and to expose a wafer in regions corresponding to the additional dark defects and the remaining dark defects with the suitable correction shape and dose and/or to expose the wafer in regions corresponding to the design/OPC weak spots on the reticle;
- providing matching overlay marks and/or dark areas corresponding to the written overlay marks and/or programmed metrology structures on the reticle or on another reticle used for patterning a layer on the wafer prior to or subsequent to exposing the resist covered wafer using the reticle and the e-beam or laser writer;
- exposing the wafer, covered with a resist, with the reticle and with the programmed e-beam or laser writer;
- and
- measuring structures corresponding to the overlay marks and/or metrology structures which are formed on the wafer after exposing the wafer covered with the resist and developing the resist, thereby monitoring the process of the exposure with the e-beam or laser writer.
Dependencies are inferred from the claim text.