Methods and apparatuses for aligning and diagnosing a laser beam

Patent metadata

Field	Value
Publication number	US-11079564-B2
Application number	US-201715655079-A
Country	US
Kind code	B2
Filing date	Jul 20, 2017
Priority date	Jul 20, 2017
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

Methods and apparatuses for aligning and diagnosing the laser beam traversing an optical train in a highly space-efficient, lower cost and/or retrofit-friendly manner are disclosed. The optical components of the optical train are mounted such that one or more optical components can direct their exit laser beam to partially or wholly scan across one or more downstream sensors. Correlation data between physical disposition of optical components and the points of impact data and/or beam quality data are employed to, among others, align and/or diagnose the laser beam and/or localize failure sites and/or optimize maintenance schedule.

First claim

What is claimed is:

1. A method for optimizing a laser beam in a photolithography system, the laser beam traversing an optical train that comprises plurality of optical components, comprising:
rasterizing, using a first optical component of the plurality of optical components such that the laser beam that exits the first optical component sweeps, responsive to the rasterizing using the first optical component, at least partially across a first sensor;
forming a correlation, using data obtained from the first sensor during the rasterizing using the first optical component, between the physical disposition of the first optical component and a point of impact of the laser beam;
ascertaining a first physical disposition of the first optical component, using data obtained from the correlation, that would cause the point of impact of the laser beam that exits the first optical component to impact a desired point on a second optical component; and
aligning the laser beam that exits the first optical component with respect to the second optical component by aligning the first optical component in accordance with the first physical disposition, wherein a footprint of the first sensor is smaller than a footprint of the laser beam.

2. A method for optimizing a laser beam in a photolithography system, the laser beam traversing an optical train that comprises plurality of optical components, comprising:
moving a first optical component of the plurality of optical components such that the laser beam that exits the first optical component sweeps, responsive to moving the first optical component, at least partially across a first sensor;
forming a correlation, using data obtained from the first sensor during moving the first optical component, between the physical disposition of the first optical component and a point of impact of the laser beam;
ascertaining a first physical disposition of the first optical component, using data obtained from the correlation, that would cause the point of impact of the laser beam that exits the first optical component to impact a desired point on a second optical component, the first sensor being positioned such that the second optical component is disposed between the first sensor and the first optical component; and
aligning the laser beam that exits the first optical component with respect to the second optical component by aligning the first optical component in accordance with the first physical disposition,
the method further comprising using a physical component having a hole configured to permit only a portion of the laser beam that exits the first optical component to enter the first sensor through the hole, the physical component being positioned between the first optical component and the first sensor, the hole having a smaller footprint than the footprint of the laser beam that exits the first optical component, wherein the first sensor and the physical component are positioned such that the assembly that comprises the first sensor and the physical component is disposed between the second optical component and the first optical component.

3. A photolithography system having an optical train comprising a plurality of optical components, the plurality of optical components configured to at least pass a laser beam from one location to another location, comprising:
a first optical component configured to at least perform rasterizing a laser beam exiting the first optical component, causing the laser beam exiting the first optical component to at least partially sweep across at least a portion of a first sensor; and
a second optical component configured to at least receive the laser beam that exits the first optical component and perform rasterizing the laser beam exiting the second optical component, causing the laser beam exiting from the second optical component to at least partially sweep across at least a portion of a second sensor, wherein a footprint of the first sensor is smaller than a footprint of the laser beam exiting the first optical component.

4. A method for optimizing a laser beam in a photolithography system, the laser beam traversing an optical train that comprises plurality of optical components, comprising:
moving a first optical component of the plurality of optical components such that the laser beam that exits the first optical component sweeps, responsive to moving the first optical component, at least partially across a first sensor;
forming a correlation, using data obtained from the first sensor during moving the first optical component, between the physical disposition of the first optical component and a point of impact of the laser beam;
ascertaining a first physical disposition of the first optical component, using data obtained from the correlation, that would cause the point of impact of the laser beam that exits the first optical component to impact a desired point on a second optical component;
aligning the laser beam that exits the first optical component with respect to the second optical component by aligning the first optical component in accordance with the first physical disposition,
the first sensor being positioned such that the second optical component is disposed between the first sensor and the first optical component, and
using a physical component having a hole configured to permit only a portion of the laser beam that exits the first optical component to enter the first sensor through the hole, the physical component being positioned between the first optical component and the first sensor, the hole having a smaller footprint than the footprint of the laser beam that exits the first optical component, wherein the first sensor and the physical component are positioned such that the second optical component is disposed between the first optical component and the assembly that comprises the first sensor and the physical component.

5. A photolithography system having an optical train comprising a plurality of optical components, the plurality of optical components configured to at least pass a laser beam from one location to another location, the photolithography system comprising:
a first optical component configured to cause the laser beam exiting the first optical component to at least partially sweep across at least a portion of a first sensor; and
a second optical component configured to at least receive the laser beam that exits the first optical component and cause the laser beam exiting the second optical component to at least partially sweep across at least a portion of a second sensor,
the first sensor being positioned such that the second optical component is disposed between the first sensor and the first optical component, the first sensor being coupled to a physical component having a hole configured to permit only a portion of the laser beam that exits the first optical component to enter the first sensor through the hole, the hole having a smaller footprint than the footprint of the laser beam that exits the first optical component, wherein the first sensor and the physical component are positioned such that the second optical component is disposed between the first optical component and the assembly that comprises the first sensor and the physical component.

Assignees

• Cymer LLC

Inventors

• Barnhart Donald Harrison

Classifications

• G01J1/0455 Primary

  having a throughhole enabling the optical element to fulfil an additional optical function, e.g. a mirror or grating having a through-hole for a light collecting or light injecting optical fibre · CPC title

• G03F7/70258 Primary

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

• G01J1/4257

  applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam (monitoring arrangements for lasers in general H01S3/0014) · CPC title

• G03F7/70558

  Dose control, i.e. achievement of a desired dose · CPC title

• G02B26/101

  with both horizontal and vertical deflecting means, e.g. raster or XY scanners (colour television using laser beams scanning a display screen H04N9/3129) · CPC title