Optically compensated unidirectional reticle bender
AssigneeASML Holdings N.V.
InventorSantiago E. Del Puerto
Life of this patent
Estimating the term…
Abstract
Patterning provided by a lithographic apparatus is optically corrected for focus errors that would result from a topology of a substrate being patterned. Focus control is provided in a cross-scan direction by bending a reticle about a scan axis based on a mapped topology of the substrate. The bending can be updated from field to field as the reticle is scanned. The bending may be unidirectional (e.g., down only), but an optical compensation element (e.g., a lens or mirror polished to a cylindrical shape or a transparent plate or mirror bent by a force actuator to a cylindrical shape) can be included in order to introduce either positive or negative curvature (or no curvature) to the beam wavefront, thereby simplifying the mechatronics of the bender.
Claims24
A lithographic apparatus including a patterning device handler, comprising:
- a support structure configured to support a patterning device configured to impart a pattern to a radiation beam, the support structure including a bender configured and arranged to apply one or more bending forces to bend the patterning device;
- and
- a projection system, disposed between the patterning device and a substrate position, capable of projecting the radiation beam onto a substrate located at the substrate position,
- wherein the support structure is configured to move in a scan direction, and the one or more bending forces are applied in a direction that is substantially perpendicular to the scan direction and is substantially parallel to a neutral axis of the patterning device.
A support structure constructed and arranged to hold a bendable patterning device in a lithographic apparatus, the support structure comprising:
- a bender configured and arranged to apply one or more bending forces to bend the patterning device in a first direction based on a mapped topology of a substrate for correcting a focus error resulting from a topology of the substrate being patterned when the patterning device imparts pattern to an incident radiation beam,
- wherein the support structure is configured to optically compensate the bending of the patterning device in a second direction being opposite to the first direction, and
- wherein the support structure is configured to move in a scan direction, and the one or more bending forces are applied in a direction substantially perpendicular to the scan direction and substantially parallel to a neutral axis of the patterning device.
A patterning device handler, comprising:
- a support structure configured to hold a patterning device having a center and a pattern,
- wherein the support structure includes a bender configured and arranged to apply one or more forces to bend the patterning device, and
- wherein the support structure is configured to move in a scan direction, and the one or more forces are applied in a direction substantially perpendicular to the scan direction and substantially parallel to a neutral axis of the patterning device.
Dependencies are inferred from the claim text.