Dual resolution spectrometer, and spectrometric measurement apparatus and method using the spectrometer

Patent metadata

Field	Value
Publication number	US-12332164-B2
Application number	US-202318118816-A
Country	US
Kind code	B2
Filing date	Mar 8, 2023
Priority date	Aug 1, 2022
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

A dual resolution spectrometer includes a slit plate comprising a slit receiving light reflected from a measurement target. The slit plate directs the light reflected from the measurement target to a first mirror. The first mirror reflects light from the slit to a diffraction grating. The diffraction grating disperses light from the first mirror according to a wavelength of the light. The diffraction grating directs light in a first wavelength region to a second mirror and directs light in a second wavelength region to a third mirror. The second mirror reflects the light in the first wavelength region to a detector. The third mirror reflects the light in the second wavelength region to the detector. The detector detects the light in the first wavelength region and the light in the second wavelength region with different resolutions from each other.

First claim

What is claimed is:

1. A dual resolution spectrometer comprising:
a slit plate comprising a slit receiving light reflected from a measurement target, the slit plate directing the light reflected from the measurement target to a first mirror;
the first mirror reflecting light from the slit to a diffraction grating;
the diffraction grating dispersing light from the first mirror according to a wavelength of the light from the first mirror, wherein the diffraction grating solely directs light in a first wavelength region among the light dispersed by the diffraction grating to a second mirror and solely directs light in a second wavelength region among the light dispersed by the diffraction grating to a third mirror, the second wavelength region does not overlap the first wavelength region;
the second mirror reflecting the light in the first wavelength region among the light dispersed by the diffraction grating to a detector;
the third mirror reflecting the light in the second wavelength region among the light dispersed by the diffraction grating to the detector; and
the detector detecting the light in the first wavelength region and the light in the second wavelength region with different resolutions from each other,
wherein the third mirror is positioned farther from the diffraction grating and the detector than the second mirror.

2. The dual resolution spectrometer of claim 1 , wherein:
the light reflected from the measurement target comprises broadband light;
the first wavelength region comprises a relatively long wavelength region; and
the second wavelength region comprises a relatively short wavelength region.

3. The dual resolution spectrometer of claim 1 , wherein:
the light reflected from the measurement target comprises broadband light;
the first wavelength region has a wavelength greater than or equal to about 400 nm; and
the second wavelength region has a wavelength less than about 400 nm.

4. The dual resolution spectrometer of claim 1 , wherein the diffraction grating disperses the light from the first mirror so that the light in the first wavelength region is incident on the second mirror and the light in the second wavelength region is directed past the second mirror to be incident on the third mirror.

5. The dual resolution spectrometer of claim 1 , wherein the first mirror comprises a collimation mirror that reflects light from the slit as collimated light.

6. The dual resolution spectrometer of claim 1 , wherein:
the second mirror and the third mirror have different focal lengths from each other, each of the second and third mirrors comprising a focusing mirror focusing light on an image detection surface of the detector; and
the second mirror and the third mirror each comprise any one of a concave mirror, an off-axis parabolic mirror, and a toroidal mirror.

7. The dual resolution spectrometer of claim 1 , wherein the detector includes an image detection surface having a long-wavelength detection region corresponding to the light from the second mirror and a short-wavelength detection region corresponding to the light from the third mirror, the long-wavelength detection region and the short-wavelength detection region are spaced apart from each other.

8. The dual resolution spectrometer of claim 7 , wherein a resolution in the short-wavelength detection region is greater than a resolution in the long-wavelength detection region.

9. A spectrometric measurement apparatus comprising:
a light source emitting broadband light;
an illumination optical system directing the broadband light from the light source to be incident on a measurement target;
an imaging optical system emitting light reflected from the measurement target to a dual resolution spectrometer; and
the dual resolution spectrometer dispersing light from the imaging optical system according to wavelength of the light from the imaging optical system and directing the dispersed light into two wavelength regions to detect the dispersed light in the two wavelength regions with different resolutions from each other,
wherein the dual resolution spectrometer solely directs light in a first wavelength region to a second mirror and solely directs light in a second wavelength region to a third mirror, the second wavelength region does not overlap the first wavelength region.

10. The spectrometric measurement apparatus of claim 9 , wherein the dual resolution spectrometer comprises:
a slit plate comprising a slit receiving the light emitted from the imaging optical system and directing the light emitted from the imaging optical system to a first mirror;
the first mirror reflecting light from the slit to a diffraction grating;
the diffraction grating dispersing light from the first mirror according to a wavelength of the light from the first mirror wherein the diffraction grating directs light in the first wavelength region among the light dispersed by the diffraction grating to the second mirror and directs light in the second wavelength region among the light dispersed by the diffraction grating to the third mirror;
the second mirror reflecting the light in the first wavelength region from among the light dispersed by the diffraction grating to a detector;
a third mirror reflecting the light in the second wavelength region from among the light dispersed by the diffraction grating to the detector; and
the detector detecting the light in the first wavelength region and the light in the second wavelength region with different resolutions from each other.

11. The spectrometric measurement apparatus of claim 10 , wherein:
the first wavelength region comprises a relatively long wavelength region; and
the second wavelength region comprises a relatively short wavelength region.

12. The spectrometric measurement apparatus of claim 10 , wherein:
the second mirror and the third mirror each comprise a focusing mirror focusing light on an image detection surface of the detector; and
the third mirror has a greater focal length and is positioned farther from the diffraction grating than the second mirror.

13. The spectrometric measurement apparatus of claim 10 , wherein the diffraction grating disperses the light from the first mirror so that the light in the first wavelength region is incident on the second mirror and the light in the second wavelength region is directed past the second mirror to be incident on the third mirror.

14. The spectrometric measurement apparatus of claim 9 , wherein the spectrometric measurement apparatus comprises a Spectroscopic Ellipsometer or a Spectroscopic Reflectometer.

15. A spectrometric measurement method comprising:
emitting broadband light from a light source;
directing the broadband light to be incident on a measurement target by using an illumination optical system;
emitting light reflected from the measurement target through an imaging optical system; and
dispersing light from the imaging optical system according to wavelength of the light from the imaging optical system by using a dual resolution spectrometer and directing the dispersed light into two wavelength regions to detect the dispersed light in the two wavelength regions with different resolutions from each other,
wherein light in a first wavelength region is solely directed to a second mirror and light in a second wavelength region is solely directed to a third mirror, the second wavelength region does not overlap the first wavelength region.

16. The spectrometric measurement method of claim 15 , wherein the dispersing of the light comprises:
emitting light from the imaging optical system via a slit of

Assignees

• Samsung Electronics Co Ltd

Inventors

• Jun Sunhong
• Kim Jaeho
• Sohn Younghoon

Classifications

• G01N21/27

  using photo-electric detection (G01N21/31 takes precedence){; circuits for computing concentration (logarithmic circuits G06G7/24; photometric circuits in general G01J)} · CPC title

• G01N21/9501

  Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20) · CPC title

• G01N21/255 Primary

  Details, e.g. use of specially adapted sources, lighting or optical systems · CPC title

• G01J3/2846

  using modulation grid; Grid spectrometers · CPC title

• G01J3/2823

  Imaging spectrometer · CPC title