In-situ optical chamber surface and process sensor

Patent metadata

Field	Value
Publication number	US-11114286-B2
Application number	US-201916378271-A
Country	US
Kind code	B2
Filing date	Apr 8, 2019
Priority date	Apr 8, 2019
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

Embodiments disclosed herein include optical sensor systems and methods of using such systems. In an embodiment, the optical sensor system comprises a housing and an optical path through the housing. In an embodiment, the optical path comprises a first end and a second end. In an embodiment a reflector is at the first end of the optical path, and a lens is between the reflector and the second end of the optical path. In an embodiment, the optical sensor further comprises an opening through the housing between the lens and the reflector.

First claim

What is claimed is:

1. An optical sensor system, comprising:
a housing;
an optical path through the housing, wherein the optical path comprises a first end and a second end;
a reflector at the first end of the optical path;
an opening through the housing between the second end of the optical path and the reflector, wherein the opening provides an unobstructed path through the housing;
a light source optically coupled to the optical path, wherein the light source is a broad band light source; and
a sensor optically coupled to the optical path.

2. The optical sensor system of claim 1 , wherein the light source and the sensor are optically coupled to the optical path by a fiber optic cable.

3. The optical sensor system of claim 2 , wherein the fiber optic cable comprises a splitter.

4. The optical sensor system of claim 1 , further comprising:
a band pass filter at a location along an optical path between the sensor and the opening.

5. The optical sensor system of claim 1 , wherein the sensor is a spectrometer or a photodiode.

6. The optical sensor system of claim 1 , wherein the light source and the sensor are integrated into the housing.

7. The optical sensor system of claim 1 , wherein the housing is transparent.

8. The optical sensor system of claim 1 , wherein the reflector is removable.

9. A method for measuring a process condition or a chamber condition in a processing chamber, comprising:
obtaining a reference signal, wherein obtaining the reference signal comprises:
emitting electromagnetic radiation from a source outside of the chamber, wherein the electromagnetic radiation is propagated along an optical path between the source and a reflector in the chamber;
reflecting the electromagnetic radiation back along the optical path with the reflector; and
sensing the reflected electromagnetic radiation with a sensor that is optically coupled to the optical path;

obtaining a process signal, wherein obtaining the process signal comprises:
sensing electromagnetic radiation emitted in the processing chamber that travels along the optical path with the sensor; and

comparing the process signal with the reference signal.

10. The method of claim 9 , wherein the reference signal is obtained when no process is being implemented in the chamber.

11. The method of claim 9 , wherein the reference signal is obtained during a process in the chamber.

12. The method of claim 9 , wherein the process signal is obtained when the source is off.

13. The method of claim 9 , wherein the process signal is obtained when the source is on.

14. The method of claim 9 , wherein the reference signal and the process signal are obtained during the processing of one or more substrates in the chamber.

15. An optical sensing array for a plasma processing chamber, comprising:
a plurality of optical sensing systems oriented around a perimeter of the processing chamber, wherein each of the plurality of optical sensing systems comprise:
a housing;
an optical path through the housing, wherein the optical path comprises a first end and a second end;
a reflector at the first end of the optical path;
an opening through the housing between the second end of the optical path and the reflector, wherein the opening provides an unobstructed path through the housing; and
a light source optically coupled to the optical path, wherein the light source is a broad band light source; and
a sensor optically coupled to the optical path.

16. The optical sensing array of claim 15 , wherein the plurality of optical sensing systems are configured to provide uniformity data of a plasma condition, a wall condition, or a plasma condition and a wall condition.

17. The optical sensing array of claim 15 , wherein the plurality of optical sensing systems are configured to provide chamber drift monitoring.

18. An optical sensor system, comprising:
a housing;
an optical path through the housing, wherein the optical path comprises a first end and a second end;
a reflector at the first end of the optical path;
an opening through the housing between the second end of the optical path and the reflector, wherein the opening provides an unobstructed path through the housing;
a light source optically coupled to the optical path; and
a sensor optically coupled to the optical path, wherein the light source and the sensor are optically coupled to the optical path by a fiber optic cable.

19. An optical sensor system, comprising:
a housing;
an optical path through the housing, wherein the optical path comprises a first end and a second end;
a reflector at the first end of the optical path;
an opening through the housing between the second end of the optical path and the reflector, wherein the opening provides an unobstructed path through the housing;
a light source optically coupled to the optical path;
a sensor optically coupled to the optical path; and
a band pass filter at a location along an optical path between the sensor and the opening.

20. An optical sensor system, comprising:
a housing;
an optical path through the housing, wherein the optical path comprises a first end and a second end;
a reflector at the first end of the optical path;
an opening through the housing between the second end of the optical path and the reflector, wherein the opening provides an unobstructed path through the housing;
a light source optically coupled to the optical path; and
a sensor optically coupled to the optical path, wherein the sensor is a spcetrometer or a photodiode.

Assignees

• Applied Materials Inc

Inventors

• Lin Chuang-Chia
• Ummethala Upendra
• Babayan Steven E
• Lian Lei

Classifications

• H01J2237/24585

  Other variables, e.g. energy, mass, velocity, time, temperature · CPC title

• H01J37/22

  Optical {, image processing} or photographic arrangements associated with the tube · CPC title

• H01J37/32972

  Spectral analysis · CPC title

• H01J37/32917 Primary

  Plasma diagnostics · CPC title

• G01J3/443

  Emission spectrometry · CPC title