Dense line extreme ultraviolet lithography system with distortion matching

Patent metadata

Field	Value
Publication number	US-11067900-B2
Application number	US-202016914143-A
Country	US
Kind code	B2
Filing date	Jun 26, 2020
Priority date	May 19, 2016
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

An extreme ultraviolet lithography system (10) that creates a new pattern (330) having a plurality of densely packed parallel lines (332) on a workpiece (22), the system (10) includes a patterning element (16); an EUV illumination system (12) that directs an extreme ultraviolet beam (13B) at the patterning element (16); a projection optical assembly (18) that directs the extreme ultraviolet beam diffracted off of the patterning element (16) at the workpiece (22) to create a first stripe (364) of generally parallel lines (332) during a first scan (365); and a control system (24). The workpiece (22) includes an existing pattern (233) that is distorted. The control system (24) selectively adjusts a control parameter during the first scan (365) so that the first stripe (364) is distorted to more accurately overlay the portion of existing pattern (233) positioned under the first stripe (364).

First claim

What is claimed is:

1. An extreme ultraviolet lithography system that transfers a pattern of a plurality of parallel lines onto a workpiece that includes an existing pattern, the workpiece including a first die, a second die, and a third die that are aligned along a first axis, with the second die being positioned between the first die and the third die along the first axis, the lithography system comprising:
a workpiece stage assembly that retains and moves the workpiece;
a projection optical assembly that projects and transfers an image of the plurality of parallel lines, within an exposure field, onto the workpiece as the workpiece is moved relative to the exposure field during a first scan, exposure during the first scan resulting in a first portion of a first stripe of the imaged plurality of parallel lines extending generally along the first axis, the first scan sequentially exposing the first die and the third die; and
a control system that controls the workpiece stage assembly to move the workpiece relative to the exposure field along a first scan trajectory that is generally along the first axis during the first scan;
wherein the projection optical assembly further projects and transfers the image of the plurality of parallel lines, within the exposure field, onto the workpiece as the workpiece is moved relative to the exposure field during a second scan, exposure during the second scan resulting in a second portion of the first stripe of the imaged plurality of parallel lines extending generally along the first axis, the second scan exposing the second die, but not exposing the first die and the third die; and
wherein the control system controls the workpiece stage assembly to move the workpiece relative to the exposure field along a second scan trajectory that is generally along the first axis during the second scan.

2. The extreme ultraviolet lithography system of claim 1 , wherein the workpiece stage assembly continuously moves the workpiece along the first scan trajectory during the first scan between exposure of the first die and exposure of the third die.

3. The extreme ultraviolet lithography system of claim 1 , wherein the workpiece stage assembly continuously moves the workpiece along the first scan trajectory during the first scan when the exposure field of the projection optical assembly overlaps with the second die.

4. The extreme ultraviolet lithography system of claim 3 , further comprising an EUV illumination system that directs an extreme ultraviolet beam at a patterning element that defines the pattern of the plurality of parallel lines; and wherein the control system controls the EUV illumination system so that the second die is not exposed during the first scan when the exposure field of the projection optical assembly overlaps with the second die.

5. An extreme ultraviolet lithography system that transfers a pattern of a plurality of parallel lines onto a workpiece that includes an existing pattern, the workpiece including a first die, a second die, and a third die that are aligned along a first axis, with the second die being positioned between the first die and the third die along the first axis, the lithography system comprising:
a workpiece stage assembly that retains and moves the workpiece;
a projection optical assembly that projects and transfers an image of the plurality of parallel lines, within an exposure field, onto the workpiece as the workpiece is moved relative to the exposure field during a first scan, exposure during the first scan resulting in a first portion of a first stripe of the imaged plurality of parallel lines extending generally along the first axis, the first scan sequentially exposing the first die and the third die; and
a control system that controls the workpiece stage assembly to move the workpiece relative to the exposure field along a first scan trajectory that is generally along the first axis during the first scan;
wherein the control system selectively adjusts a control parameter during the first scan; and wherein the control parameter includes selectively adjusting the first scan trajectory to include some movement along a second axis that is orthogonal to the first axis during the first scan so that the first stripe of the imaged plurality of parallel lines more accurately overlays the portion of existing pattern positioned under the first stripe of the imaged plurality of parallel lines relative to if the movement along the second axis is not performed.

6. The extreme ultraviolet lithography system of claim 5 , wherein the control parameter includes selectively adjusting the first scan trajectory to include some movement about a third axis that is orthogonal to the first and second axes during the first scan so that the first stripe of the imaged plurality of parallel lines more accurately overlays the portion of existing pattern positioned under the first stripe of the imaged plurality of parallel lines.

7. The extreme ultraviolet lithography system of claim 6 , wherein during the first scan, the movement along the second axis or about the third axis is a function of a workpiece position of the workpiece along the first axis relative to if the movement along the second axis or about the third axis is not performed.

8. An extreme ultraviolet lithography system that transfers a pattern of a plurality of parallel lines onto a workpiece that includes an existing pattern, the workpiece including a first die, a second die, and a third die that are aligned along a first axis, with the second die being positioned between the first die and the third die along the first axis, the lithography system comprising:
a workpiece stage assembly that retains and moves the workpiece;
a projection optical assembly that projects and transfers an image of the plurality of parallel lines, within an exposure field, onto the workpiece as the workpiece is moved relative to the exposure field during a first scan, exposure during the first scan resulting in a first portion of a first stripe of the imaged plurality of parallel lines extending generally along the first axis, the first scan sequentially exposing the first die and the third die; and
a control system that controls the workpiece stage assembly to move the workpiece relative to the exposure field along a first scan trajectory that is generally along the first axis during the first scan;
wherein the control system controls the workpiece stage assembly to move the workpiece relative to the exposure field along the first axis and along a second axis that is orthogonal to the first axis during the first scan when the exposure field of the projection optical assembly overlaps with the second die.

9. A method for transferring a pattern of a plurality of parallel lines onto a workpiece that includes an existing pattern, the workpiece including a first die, a second die, and a third die that are aligned along a first axis, with the second die being positioned between the first die and the third die along the first axis, the method comprising the steps of:
moving the workpiece with a workpiece stage mover assembly;
projecting and transferring an image of the plurality of parallel lines with a projection optical assembly, within an exposure field, onto the workpiece as the workpiece is moved relative to the exposure field during a first scan, exposure during the first scan resulting in a first portion of a first stripe of the imaged plurality of parallel lines extending generally along the first axis, the first scan sequentially exposing the first die and the third die; and
controlling the workpiece stage assembly with a control system to move the workpiece relative to the exposure field along a first scan trajectory that is generally along the fir

Assignees

• Nikon Corp

Inventors

• Binnard Michael B

Classifications

• G03F7/70725

  control · CPC title

• G03F7/70633

  Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching · CPC title

• G03F7/70783 Primary

  Handling stress or warp of chucks, masks or workpieces, e.g. to compensate for imaging errors or considerations related to warpage of masks or workpieces due to their own weight · CPC title

• G03F7/70258

  Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system · CPC title

• G03F7/70358

  Scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging · CPC title