Substrate provided with an alignment mark in a substantially transmissive process layer, mask for exposing said mark, device manufacturing method, and device manufactured thereby
AssigneeASML Netherlands B.V.
InventorRichard Johannes Van Haren
Life of this patent
Estimating the term…
Abstract
A substrate provided with an alignment mark in a substantially transmissive process layer overlying the substrate, said mark comprising high reflectance areas for reflecting radiation of an alignment beam of radiation, and low reflectance areas for reflecting less radiation of the alignment beam, wherein the high reflectance areas comprise at least one substantially linear sub-grating. In one example, a substantially linear sub-grating comprises a plurality of spaced square regions.
Claims23
A mark for use in lithographic overlay measurements, comprising:
- at least one relatively high reflectance area to reflect radiation of an alignment beam of radiation;
- and
- at least one relatively low reflectance area to reflect less radiation of the alignment beam,
- wherein the at least one relatively high reflectance area comprises a plurality of substantially linear sub-gratings, at least one of the substantially linear sub-gratings comprising a plurality of spaced square regions.
A device manufacturing method, comprising:
- providing a substrate comprising an alignment mark that is disposed in a transmissive layer, the alignment mark comprising a relatively high reflectance area and a low reflectance area that is at least partially covered by a layer of radiation sensitive material;
- aligning the alignment mark to a references with an alignment beam of radiation;
- providing a projection beam of radiation using a radiation system;
- using a patterning structure to endow the projection beam with a patterned cross-section;
- and
- projecting the patterned beam of radiation onto a target portion of the layer of radiation sensitive material,
- wherein the relatively high reflectance area comprises a plurality of substantially linear sub-gratings, at least one of the substantially linear sub-gratings comprising a plurality of spaced square regions.
A mask comprising a pattern for exposing an alignment mark, the alignment mark comprising:
- at least one relatively high reflectance area to reflect radiation of an alignment beam of radiation;
- and
- at least one relatively low reflectance area to reflect less radiation of the alignment beam,
- wherein the at least one relatively high reflectance area comprises a plurality of substantially linear sub-gratings, at least one of the substantially linear sub-gratings comprising a plurality of spaced square regions.
Simulation software for obtaining an alignment mark, wherein the alignment mark comprises:
- at least one relatively high reflectance area to reflect radiation of an alignment beam of radiation;
- and
- at least one relatively low reflectance area to reflect less radiation of the alignment beam,
- wherein the at least one relatively high reflectance area comprises a plurality of substantially linear sub-gratings, at least one of the substantially linear sub-gratings comprising a plurality of spaced square regions.
Dependencies are inferred from the claim text.