Wafer-based light source parameter control

Patent metadata

Field	Value
Publication number	US-9989866-B2
Application number	US-201615295524-A
Country	US
Kind code	B2
Filing date	Oct 17, 2016
Priority date	Oct 17, 2016
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

A photolithography method includes producing, from an optical source, a pulsed light beam; and scanning the pulsed light beam across a substrate of a lithography exposure apparatus to expose the substrate with the pulsed light beam including exposing each sub-area of the substrate with the pulsed light beam. A sub-area is a portion of a total area of the substrate. For each sub-area of the substrate, a lithography performance parameter associated with the sub-area of the substrate is received; the received lithography performance parameter is analyzed, and, based on the analysis, a first spectral feature of the pulsed light beam is modified and a second spectral feature of the pulsed light beam is maintained.

First claim

What is claimed is:

1. A photolithography apparatus comprising:
an optical source configured to produce a pulsed light beam;
a spectral feature selection system that optically interacts with the pulsed light beam;
a scanning optical system configured to scan the pulsed light beam across a substrate positioned in a lithographic apparatus;
a metrology apparatus configured to determine at least one lithography performance parameter at each sub-area of the substrate, in which a sub-area is a portion of a total area of the substrate and in which a lithography performance parameter is a characteristic associated with the substrate or with the pulsed light beam as it interacts with the substrate; and
a control system connected to the spectral feature selection system, the optical source, and the metrology apparatus, and configured to, at each substrate sub-area:
receive the determined lithography performance parameter;
analyze the determined lithography performance parameter; and
based on the analysis of the determined lithography performance parameter:
modify a first spectral feature of the pulsed light beam by sending a first signal to the spectral feature selection system, wherein the modification of the first spectral feature causes a change in a second spectral feature of the pulsed light beam; and
adjust the second spectral feature of the pulsed light beam to compensate for the change to the second spectral feature that is caused by the modification of the first spectral feature, wherein adjusting the second spectral feature comprises sending a second signal to the spectral feature selection system while the first spectral feature of the pulsed light beam is being modified.

2. The photolithography apparatus of claim 1 , wherein each sub-area of the substrate is an exposure field of the substrate or each sub-area corresponds to a single pulse of the light beam.

3. The photolithography apparatus of claim 1 , wherein the spectral feature selection system comprises a spectral feature actuation mechanism including an actuation system configured to cause one or more elements of the spectral feature actuation mechanism to be altered to thereby alter interaction with the pulsed light beam.

4. The photolithography apparatus of claim 1 , wherein the lithography performance parameter includes one or more of a mean offset of a position of the substrate from a desired position and a stage vibration of the substrate.

5. The photolithography apparatus of claim 1 , wherein the lithography performance parameter includes a position of the substrate that varies from central sub-areas of the substrate to sub-areas at an edge of the substrate.

6. A photolithography apparatus comprising:
an optical source configured to produce a pulsed light beam;
a spectral feature selection system that optically interacts with the pulsed light beam, wherein the spectral feature selection system comprises:
a dispersive optical element and a beam expander including at least three refractive optical elements, the pulsed light beam interacting with each of the dispersive optical element and the plurality of refractive optical elements; and
an actuation system that includes a plurality of actuators, each of the actuators in the plurality causing one of the at least three refractive optical elements to rotate relative to the pulsed light beam;
wherein the actuation system includes a rapid actuator associated with at least one of the refractive optical elements, the rapid actuator including a rotation stage that rotates about a rotation axis and includes a region that is mechanically linked to the associated refractive optical element to rotate the associated refractive optical element about the rotation axis;

a scanning optical system configured to scan the pulsed light beam across a substrate positioned in a lithographic apparatus;
a metrology apparatus configured to determine at least one lithography performance parameter at each sub-area of the substrate, in which a sub-area is a portion of a total area of the substrate;
a control system connected to the spectral feature selection system, the optical source, and the metrology apparatus, and configured to, at each substrate sub-area:
receive the determined lithography performance parameter;
analyze the determined lithography performance parameter; and
based on the analysis of the determined lithography performance parameter: modify a first spectral feature of the pulsed light beam by sending a first signal to the spectral feature selection system; and maintain a second spectral feature of the pulsed light beam by sending a second signal to the spectral feature selection system while the first spectral feature of the pulsed light beam is being modified.

7. The photolithography apparatus of claim 6 , wherein the rotation of a first refractive optical elements causes the second spectral feature of the pulsed light beam to be changed in a relatively coarse manner, the rotation of a second refractive optical element causes the first spectral feature of the pulsed light beam to be changed in a relatively fine manner, and the rotation of a third refractive optical elements causes the second spectral feature of the pulsed light beam to be changed in a relatively fine manner.

8. The photolithography apparatus of claim 7 , wherein the beam expander includes a fourth refractive optical element, and the rotation of the fourth refractive optical element causes the first spectral feature of the pulsed light beam to be changed in a relatively coarse manner.

9. The photolithography apparatus of claim 1 , wherein:
the control system analyzes the determined lithography performance parameter by determining whether the lithography performance parameter is outside an acceptable range; and
the control system modifies the first spectral feature of the pulsed light beam if it is determined that the lithography performance parameter is outside an acceptable range by sending the signal to the spectral feature selection system.

10. The photolithography apparatus of claim 1 , wherein the scanning optical system is configured to move one or more of the pulsed light beam and the substrate relative to each other along a lateral plane such that the pulsed light beam interacts with each sub-area of the substrate, wherein the lateral plane is perpendicular to an axial direction along which the pulsed light beam is directed.

11. A photolithography method comprising:
producing, from an optical source, a pulsed light beam;
scanning the pulsed light beam across a substrate of a lithography exposure apparatus to expose the substrate with the pulsed light beam including exposing each sub-area of the substrate with the pulsed light beam, wherein a sub-area is a portion of a total area of the substrate; and
for each sub-area of the substrate:
receiving a lithography performance parameter associated with the sub-area of the substrate, wherein the lithography performance parameter is a characteristic associated with the substrate or with the pulsed light beam as it interacts with the substrate;
analyzing the received lithography performance parameter; and
based on the analysis:
modifying at least a first spectral feature of the pulsed light beam, wherein modifying the first spectral feature causes a change in a second spectral feature of the pulsed light beam, and
adjusting at least the second spectral feature of the pulsed light beam to compensate for the change to the second spectral feature that is caused by the modification of the first spectral feature.

12. The method of claim 11 , wherein receiving the lithography performance parameter at each sub-area of the substrat

Assignees

• Cymer LLC

Inventors

• Mason Eric Anders
• Zurita Omar
• Rechtsteiner Gregory Allen
• Conley Willard Earl

Classifications

• G03F7/70575 Primary

  Wavelength control, e.g. control of bandwidth, multiple wavelength, selection of wavelength or matching of optical components to wavelength · CPC title

• G03F7/70041 Primary

  by pulsed sources, e.g. multiplexing, pulse duration, interval control or intensity control · CPC title

• G03F7/70625 Primary

  Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness · CPC title

• G03F7/706849

  Irradiation branch, e.g. optical system details, illumination mode or polarisation control · CPC title