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US 2006/0139592 A1Published application
Latent overlay metrology
AssigneeASML Netherlands B.V.
InventorsArie Den Boef, Jacobus Burghoorn, Mircea Dusa, Antoine Kiers, Maurits Van Der Schaar
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Abstract
An apparatus and method for improved latent overlay metrology is disclosed. In an embodiment, a scatterometer and an overexposed overlay target are used to obtain more robust overlay measurement. Overlay metrology and exposure may be done in parallel.
Claims42
A lithographic apparatus, comprising:
- an illumination system configured to condition a beam of radiation;
- a support configured to hold a patterning device, the patterning device configured to impart the beam with a pattern in its cross-section;
- a substrate table configured to hold a substrate;
- a projection system configured to project the patterned beam onto a portion of the substrate;
- and
- an exposure unit, including an additional patterning device, configured to print a target onto the substrate.
3 more elements
A method of measuring latent overlay of a resist layer with respect to a process layer on a substrate, comprising:
- measuring a position of a substrate with respect to a reference;
- exposing a target in the resist layer with beam of radiation having a high exposure dose in accordance with the measured position of the substrate;
- and
- measuring the overlay of the resist layer with respect to the process layer at the exposed target.
1 more element
Dependencies are inferred from the claim text.