Lithographic apparatus, temperature sensor, and fiber Bragg grating sensor

Patent metadata

Field	Value
Publication number	US-12422758-B2
Application number	US-202218284161-A
Country	US
Kind code	B2
Filing date	Mar 21, 2022
Priority date	Apr 8, 2021
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

A lithographic apparatus includes an illumination system, a projection system, a temperature-sensitive object, and a temperature sensor that includes a detector and waveguide device that is thermally coupled to the temperature-sensitive object and includes an input end, a downstream end, and first and second scattering features. The illumination system illuminates a pattern of a patterning device. The projection system projects an image of the pattern onto a substrate. Based on temperature, the first scattering feature reflects a first spectrum. Radiation not reflected by the first scattering feature is allowed downstream. Based on temperature, the second scattering feature reflects a second spectrum different from the first spectrum. Radiation not reflected by the second scattering feature is allowed downstream. The detector is disposed to receive radiation including the reflected first and second spectra from the input end and generates a measurement signal based on the received radiation.

First claim

The invention claimed is:

1. A lithographic apparatus comprising:
an illumination system configured to illuminate a pattern of a patterning device;
a projection system configured to project an image of the pattern onto a substrate;
a temperature-sensitive object; and
a temperature sensor thermally coupled to the temperature sensitive-object, wherein the temperature sensor comprises:
a waveguide device comprising:
an input end configured to receive input radiation;
a downstream end opposite the input end;
a first scattering feature configured to reflect a first spectrum based on a temperature at the first scattering feature, wherein radiation not reflected by the first scattering feature is allowed to propagate downstream; and
a second scattering feature configured to reflect a second spectrum based on a temperature at the second scattering feature, wherein radiation not reflected by the second scattering feature is allowed to propagate downstream;

a detector disposed to receive radiation comprising the reflected first and second spectra from the input end and configured to generate a measurement signal based on the received radiation; and
a controller configured to receive the measurement signal and to generate a control signal based on the measurement signal,
wherein the temperature-sensitive object comprises a deformable mirror configured to receive the control signal and to adjust shape based on the received control signal.

2. The lithographic apparatus of claim 1 , wherein:
the first scattering feature is further configured such that the reflected first spectrum changes based on a temperature change at the first scattering feature; and
the second scattering feature is further configured such that the reflected second spectrum changes based on a temperature change at the second scattering feature.

3. The lithographic apparatus of claim 1 , wherein:
the temperature sensor further comprises a radiation source configured to generate the input radiation; and
the input radiation comprises the first and second spectra.

4. The lithographic apparatus of claim 1 , wherein the waveguide device is enclosed in the temperature-sensitive object and a length of the waveguide device is disposed along a direction perpendicular to a temperature-sensitive surface of the temperature-sensitive object.

5. The lithographic apparatus of claim 1 , wherein the waveguide device is enclosed in the deformable mirror and is disposed proximal to an optical surface of the deformable mirror such that the first and second scattering features are in thermal communication with different regions of the optical surface.

6. The lithographic apparatus of claim 1 , wherein the first and second scattering features are each a Bragg reflector.

7. The lithographic apparatus of claim 1 , wherein the waveguide device is an optical fiber and the first and second scattering features are each a fiber Bragg grating.

8. The lithographic apparatus of claim 1 , wherein the waveguide device is arranged in a spiral pattern.

9. The lithographic apparatus of claim 1 , wherein the waveguide device is arranged in a serpentine pattern.

10. A lithographic apparatus comprising:
an illumination system configured to illuminate a pattern of a patterning device;
a projection system configured to project an image of the pattern onto a substrate;
a temperature-sensitive object; and
a temperature sensor thermally coupled to the temperature sensitive-object, wherein the temperature sensor comprises:
a waveguide device comprising:
an input end configured to receive input radiation;
a downstream end opposite the input end;
a first scattering feature configured to reflect a first spectrum based on a temperature at the first scattering feature, wherein radiation not reflected by the first scattering feature is allowed to propagate downstream;
a second scattering feature configured to reflect a second spectrum based on a temperature at the second scattering feature, wherein radiation not reflected by the second scattering feature is allowed to propagate downstream; and

a detector disposed to receive radiation comprising the reflected first and second spectra from the input end and configured to generate a measurement signal based on the received radiation;

wherein:
the temperature sensor further comprises one or more additional waveguide devices thermally coupled to the temperature-sensitive object;
the one or more additional waveguide devices each comprises scattering features configured to reflect corresponding spectra based on temperatures at corresponding ones of the scattering features;
radiation not reflected by the corresponding ones of the scattering features is allowed to propagate downstream; and
the one or more additional waveguide devices are disposed parallel to, and spaced apart from, the waveguide device.

11. A lithographic apparatus comprising:
an illumination system configured to illuminate a pattern of a patterning device;
a projection system configured to project an image of the pattern onto a substrate;
a temperature-sensitive object; and
a temperature sensor thermally coupled to the temperature sensitive-object, wherein the temperature sensor comprises:
a waveguide device comprising:
an input end configured to receive input radiation;
a downstream end opposite the input end;
a first scattering feature configured to reflect a first spectrum based on a temperature at the first scattering feature, wherein radiation not reflected by the first scattering feature is allowed to propagate downstream; and
a second scattering feature configured to reflect a second spectrum based on a temperature at the second scattering feature, wherein radiation not reflected by the second scattering feature is allowed to propagate downstream; and

a detector disposed to receive radiation comprising the reflected first and second spectra from the input end and configured to generate a measurement signal based on the received radiation;

wherein:
the temperature sensor further comprises one or more additional waveguide devices thermally coupled to the temperature-sensitive object;
the one or more additional waveguide devices each comprises scattering features configured to reflect corresponding spectra based on temperatures at corresponding ones of the scattering features;
radiation not reflected by the corresponding ones of the scattering features is allowed to propagate downstream; and
the one or more additional waveguide devices are disposed at corresponding one or more depths, the one or more depths measured relative to a temperature-sensitive surface of the temperature-sensitive object, but different from a depth of the waveguide device.

12. A lithographic apparatus comprising:
an illumination system configured to illuminate a pattern of a patterning device;
a projection system configured to project an image of the pattern onto a substrate;
a temperature-sensitive object; and
a temperature sensor thermally coupled to the temperature sensitive-object, wherein the temperature sensor comprises:
a waveguide device comprising:
an input end configured to receive input radiation;
a downstream end opposite the input end;
a first scattering feature configured to reflect a first spectrum based on a temperature at the first scattering feature, wherein radiation not reflected by the first scattering feature is allowed to propagate downstream; and
a second scattering feature configured to reflect a second spectrum based on a temperature at the second scattering feature, wherein radiation not reflected by the second scattering feature is allowed to propagate downstream;

a detec

Assignees

• Asml Holding Nv
• Asml Netherlands Bv
• Asml Netherlands B V & Asml Holding N V

Inventors

• Ajgaonkar Mahesh Upendra
• Swinkels Gerardus Hubertus Petrus Maria
• Van Bokhoven Laurentius Johannes Adrianus
• Klugkist Joost André
• Bos Koen Martin Willem Jan

Classifications

• G03F7/7085 Primary

  Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load · CPC title

• G03F7/70316

  Details of optical elements, e.g. of Bragg reflectors, extreme ultraviolet [EUV] multilayer or bilayer mirrors or diffractive optical elements · CPC title

• G03F7/70233

  Optical aspects of catoptric systems, i.e. comprising only reflective elements, e.g. extreme ultraviolet [EUV] projection systems · CPC title

• G03F7/702

  Reflective illumination, i.e. reflective optical elements other than folding mirrors, e.g. extreme ultraviolet [EUV] illumination systems · CPC title

• G01K11/3206

  at discrete locations in the fibre, e.g. using Bragg scattering · CPC title