Capacitive sensor for monitoring gas concentration

Patent metadata

Field	Value
Publication number	US-12228534-B2
Application number	US-202418604257-A
Country	US
Kind code	B2
Filing date	Mar 13, 2024
Priority date	Feb 3, 2021
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

Embodiments disclosed herein include gas concentration sensors, and methods of using such gas concentration sensors. In an embodiment, a gas concentration sensor comprises a first electrode. In an embodiment the first electrode comprises first fingers. In an embodiment, the gas concentration sensor further comprises a second electrode. In an embodiment, the second electrode comprises second fingers that are interdigitated with the first fingers.

First claim

What is claimed is:

1. A semiconductor processing tool, comprising: a chamber; a gas line for providing a source gas to the chamber; and a gas concentration sensor in the gas line, wherein the gas concentration sensor comprises: a first electrode, wherein the first electrode comprises first fingers; and a second electrode, wherein the second electrode comprises second fingers that are interdigitated with the first fingers, the first electrode comprising a first plate along a vertical direction relative to the substrate, the second electrode comprising a second plate along the vertical direction, and the first fingers and second fingers laterally between the first electrode and the second electrode along a horizontal direction relative to the substrate, and wherein the second electrode is capacitively coupled to the first electrode to provide a capacitance to measure a gas concentration.

2. The semiconductor processing tool of claim 1 , wherein the first fingers and the second fingers are plates or pins.

3. The semiconductor processing tool of claim 1 , wherein gas flows through the interdigitated first fingers and second fingers.

4. The semiconductor processing tool of claim 1 , wherein the semiconductor processing tool is an atomic layer deposition (ALD) tool.

5. A gas feed architecture, comprising: a first gas line, wherein the first gas line receives a first gas from a first gas source; an ampule along the first gas line, wherein the ampule supplies a second gas to the first gas line; a first gas concentration sensor after the ampule, wherein the first gas concentration sensor comprises: a first electrode, wherein the first electrode comprises first fingers;
and a second electrode, wherein the second electrode comprises second fingers that are interdigitated with the first fingers, the first electrode comprising a first plate along a vertical direction relative to the substrate, the second electrode comprising a second plate along the vertical direction, and the first fingers and second fingers laterally between the first electrode and the second electrode along a horizontal direction relative to the substrate, and wherein the second electrode is capacitively coupled to the first electrode to provide a capacitance to measure a gas concentration.

6. The gas feed architecture of claim 5 , further comprising:
a second gas sensor before the ampule.

7. The gas feed architecture of claim 5 , further comprising:
a second gas line, wherein the second gas line receives the first gas, and wherein the second gas line merges with the first gas line at a third gas line.

8. The gas feed architecture of claim 7 , wherein the first gas concentration sensor is between the ampule and the third gas line.

9. The gas feed architecture of claim 7 , further comprising:
a second gas sensor on the second gas line.

10. The gas feed architecture of claim 9 , wherein approximately 90% or more of gas flow into the third gas line is from the second gas line, or wherein approximately 1% or less of gas flow into the third gas line is the second gas.

11. A semiconductor processing tool, comprising:
a chamber; and
a gas concentration sensor coupled to the chamber, wherein the gas concentration sensor comprises:
a first electrode above a substrate, wherein the first electrode comprises first fingers; and
a second electrode above the substrate, wherein the second electrode comprises second fingers that are interdigitated with the first fingers, the first electrode comprising a first plate along a vertical direction relative to the substrate, the second electrode comprising a second plate along the vertical direction, and the first fingers and second fingers laterally between the first electrode and the second electrode along a horizontal direction relative to the substrate, and wherein the second electrode is capacitively coupled to the first electrode to provide a capacitance to measure a gas concentration.

12. The semiconductor processing tool of claim 11 , wherein the first electrode and the second electrode of the gas concentration sensor are raised up from a surface of the substrate.

13. The semiconductor processing tool of claim 11 , wherein the substrate of the gas concentration sensor is a flexible substrate.

14. The semiconductor processing tool of claim 13 , wherein the flexible substrate of the gas concentration sensor is cylindrical.

15. The semiconductor processing tool of claim 13 , wherein the first electrode of the gas concentration sensor comprises a first line, wherein the first fingers extend away from the first line from two surfaces of the first line, and wherein the second electrode of the gas concentration sensor comprises a second line, wherein the second fingers extend away from the second line from two surfaces of the second line.

16. The semiconductor processing tool of claim 11 , wherein the first fingers and the second fingers of the gas concentration sensor are plates.

17. The semiconductor processing tool of claim 11 , wherein the first fingers and the second fingers of the gas concentration sensor are pins.

18. The semiconductor processing tool of claim 11 , wherein the gas concentration sensor is provided in a gas feed line of the semiconductor processing tool.

19. The semiconductor processing tool of claim 11 , wherein the gas concentration sensor further comprises:
a temperature sensor; and
a pressure sensor.

Assignees

• Applied Materials Inc

Inventors

• Li Xiaopu
• Bera Kallol
• Pan Yaoling
• Chan Kelvin
• Bayati Amir
• Kraus Philip Allan
• Choi Kenric T
• Durand William John

Classifications

• H10P72/0604

  Process monitoring, e.g. flow or thickness monitoring · CPC title

• H10P72/0402

  Apparatus for fluid treatment (H10P72/0441, H10P72/0448 take precedence) · CPC title

• C23C16/45544

  characterized by the apparatus · CPC title

• C23C16/45561

  Gas plumbing upstream of the reaction chamber · CPC title

• C23C16/52

  Controlling or regulating the coating process {(C23C16/45557, C23C16/279 take precedence)} · CPC title