Apparatus and process for sensing fluoro species in semiconductor processing systems

• US 7,475,588 B2
• Filed: 02/14/2005
• Issued: 01/13/2009
• Est. Priority Date: 10/17/2002
• Status: Expired due to Fees

• Current Assignee: Entegris Incorporated
• Original Assignee: Advanced Technology Materials, Inc. (Entegris Incorporated)
• Inventors: Neuner, Jeffrey W., DiMeo, Jr., Frank, Roeder, Jeffrey F., Baum, Thomas H., Welch, James, King, Mackenzie E., Chen, Philip S. H., Stawacz, Michele, Chen, Ing-Shin
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): SAINT SURIN, JACQUES M
• Application Number:
  US11/057,734
• Publication Number:
  US 20050205424A1
• Time in Patent Office: 1,429 Days
• Field of Search: 73/310.5, 73/310.6, 73/232.1, 73/233.5, 73/232.2, 73/232, 73/240.6, 73/250.1, 204/431, 204/415, 436/144, 436/147, 422/83
• US Class Current: 73/31.05
• CPC Class Codes: G01N 27/128 Microapparatus
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/32981 Gas analysis
• CPC Class Codes: Y10T 29/49007 Indicating transducer
• CPC Class Codes: Y10T 436/17 Nitrogen containing
• CPC Class Codes: Y10T 436/19 Halogen containing

Abstract

A gas detector and process for detecting a fluorine-containing species in a gas containing same, e.g., an effluent of a semiconductor processing tool undergoing etch cleaning with HF, NF₃, etc. The detector in a preferred structural arrangement employs a microelectromechanical system (MEMS)-based device structure and/or a free-standing metal element that functions as a sensing component and optionally as a heat source when elevated temperature sensing is required. The free-standing metal element can be fabricated directly onto a standard chip carrier/device package so that the package becomes a platform of the detector.

Claims

1. A gas sensor assembly including an array of posts, and one or more free-standing metal sensor wire(s) woven about said posts to provide a woven wire structure for contacting with gas susceptible to presence of one or more target species therein with which the wire is interactive to produce a response indicative of the presence of said one or more target species.

2. The gas sensor assembly of claim 1, wherein the posts are formed of a metal material.

3. The gas sensor assembly of claim 1, wherein the posts are formed of Vespel®

polyimide.

4. The gas sensor assembly of claim 2, wherein the wire is bonded at anchoring points to selected ones of said posts.

5. The gas sensing assembly according to claim 1, wherein the woven wire structure is vertically oriented.

6. The gas sensing assembly according to claim 1, wherein the woven wire structure is horizontally oriented.

7. The gas sensing assembly of claim 1, wherein the gas sensing wire is wrapped around posts in a racetrack pattern.

8. The gas sensing assembly of claim 1, wherein the gas sensing wire is wrapped around posts in a figure-eight pattern.

9. The gas sensing assembly of claim 1, wherein the gas sensing wire is wrapped around posts in a “

S”

-shaped pattern.

10. The gas sensing assembly of claim 1, comprising a Vespel®

polyimide block to which said posts are mounted.

11. The gas sensing assembly of claim 1, further comprising a Vespel®

polyimide block machined to form at least some of said posts.

12. The gas sensing assembly of claim 1, comprising a plurality of wires respectively formed of different sensing metals, and/or including a multiplicity of weaving conformations, to provide a matrix structure.

13. The gas sensing assembly of claim 1, including a machined Vespel®

polyimide structure for support of the woven wire structure.

14. The gas sensing assembly of claim 13, wherein the machined Vespel®

polyimide structure comprises cut channels therein through which gas sensing wire is woven.

15. The gas sensing assembly of claim 13, wherein the machined Vespel®

polyimide structure forms vertical colunms around which gas sensing wire is wound.

16. The gas sensing assembly of claim 13, wherein the machined Vespel®

polyimide structure includes cut portions supporting gas sensing wire in a controlled vertical position.

17. The gas sensing assembly of claim 13, wherein the machined Vespel®

polyimide structure has holes formed therein through which gas sensing wire is threaded.

18. The gas sensing assembly of claim 1, further comprising a Vespel®

polyimide foraminous support supporting said woven wire structure, wherein said wire is supported in openings of said foraminous support.

21. A method of monitoring a fluid locus for the presence of a target gas species therein, the method comprising:

exposing fluid at said fluid locus to the gas sensor assembly of claim 1;

monitoring the gas sensor assembly; and

responsively generating an output signal when the gas sensor assembly exhibits a response indicative of the presence or change of concentration of the target gas species in said fluid locus.

22. A method comprising using data generated from signals produced by the gas sensor assembly of claim 1 in the manufacture of a semiconductor device.

23. A method of improving the efficiency of a semiconductor manufacturing tool, the method comprising:

using the gas sensor assembly of claim 1 to sense at least one target gas species in a gas employed by, produced by, or constituting an ambient environment of the semiconductor manufacturing tool; and

adjusting runtime characteristics of the tool based on data generated from signals produced by the gas sensor assembly.

35. The method of claim 21, further comprising communicating said output signal of the gas sensor assembly to any of a central processing unit, microprocessor, signal processing element, or signal-responsive element adapted to switch a process operation, terminate a process operation, or initiate a new process step or condition of a semiconductor manufacturing process tool.

19. A gas sensor assembly comprising a free-standing gas sensing wire element woven onto or into an insulative scaffolding member and comprising a multiplicity of windings thereon to form a woven wire structure, wherein the wire element is formed of a material exhibiting a response in exposure to target gas species, and said wire element is adapted for coupling to circuitry to produce an output indicative of presence or change of concentration of target gas species in a gaseous environment when the wire element is exposed to said target gas species.

24. A method of monitoring a fluid locus for the presence of a target gas species therein, the method comprising:

exposing fluid at said fluid locus to the gas sensor assembly of claim 19;

monitoring the gas sensor assembly; and

responsively generating an output signal when the gas sensor assembly exhibits a response indicative of the presence or change of concentration of the target gas species in said fluid locus.

25. The method of claim 24, wherein the fluid locus comprises an ambient gas environment of a manufacturing process.

26. The method of claim 24, wherein the fluid locus comprises a fluid stream in a semiconductor processing plant.

27. The method of claim 24, wherein the target gas species comprises a fluoro species selected from the group consisting of NF₃, SiF₄, C₂F₆, HF, F₂, COF₂, ClF₃, IF₃, and activated species thereof.

28. A method comprising using data generated from signals produced by the gas sensor assembly of claim 19 in the manufacture of a semiconductor device.

29. The method of claim 28, wherein the manufacture of a semiconductor device includes an ion implant process.

30. A method of improving the efficiency of a semiconductor manufacturing tool, the method comprising:

using the gas sensor assembly of claim 19 to sense at least one target gas species in a gas employed by, produced by, or constituting an ambient environment of the semiconductor manufacturing tool; and

adjusting runtime characteristics of the tool based on data generated from signals produced by the gas sensor assembly.

31. The method of claim 30, wherein the target gas species comprises a fluoro species selected from the group consisting of NF₃, SiF₄, C₂F₆, HF, F₂, COF₂, ClF₃, IF₃, and activated species thereof.

36. The method of claim 24, further comprising communicating said output signal of the gas sensor assembly to any of a central processing unit, microprocessor, signal processing element, or signal-responsive element adapted to switch a process operation, terminate a process operation, or initiate a new process step or condition of a semiconductor semiconductor manufacturing process tool.

20. A gas sensor device adapted to detect target species in a gas environment, the gas sensor device comprising:

a polymeric support structure and a first sensing element comprising a sensing wire for contacting the gas environment, wherein the sensing wire interacts with said target species in said gas environment and responsively exhibits a monitorable change in exposure to said target species, said monitorable change being correlative of concentration of said target gas species; and

a monitoring element operatively coupled with the first sensing element and adapted to generate a signal that varies in relation to concentration of said target gas species sensed by the first sensing element.

32. A method of monitoring a fluid locus for the presence of a target gas species therein, the method comprising:

exposing fluid at said fluid locus to the gas sensor device of claim 20;

monitoring the gas sensor device; and

responsively generating an output signal when the gas sensor device exhibits a response indicative of the presence or change of concentration of the target gas species in said fluid locus.

33. A method comprising using data generated from signals produced by the gas sensor device of claim 20 in the manufacture of a semiconductor device.

34. A method of improving the efficiency of a semiconductor manufacturing tool, the method comprising:

using the gas sensor device of claim 20 to sense at least one target gas species in a gas employed by, produced by, or constituting an ambient environment of the semiconductor manufacturing tool; and

adjusting runtime characteristics of the tool based on data generated from signals produced by the gas sensor device.

37. The method of claim 32, further comprising communicating said output signal of the gas sensor device to any of a central processing unit, microprocessor, signal processing element, or signal-responsive element adapted to switch a process operation, terminate a process operation, or initiate a new process step or condition of a semiconductor manufacturing process tool.

38. The gas sensor device of claim 20, wherein said gas species comprises a fluoro species.

39. The gas sensor device of claim 20, wherein at least an exterior layer of said sensing wire is composed of nickel.

40. The gas sensor device of claim 20, wherein said sensing wire comprises nickel or a nickel alloy.

41. The gas sensor device of claim 20, characterized by any of the following:

(a) the polyimide support structure comprises a plurality of posts, and the sensing wire is woven around or between the plurality of posts;

(b) the polyimide support structure defines a plurality of holes through which said sensing wire is threaded;

(c) the polyimide support structure comprises a polyimide tube; and

(d) the polyimide support structure comprises a scaffold adapted for fabricating a sensing wire array.

42. The gas sensor device of claim 20, wherein the polymeric support structure comprises any of a fluoro species-resistant polymer and a plasma-resistant polymer.

43. The gas sensor device of claim 20, wherein the polymeric support structure comprises any of polyimide and polysulfone.

44. The gas sensor device of claim 20, further comprising a second sensing element.

45. The gas sensor device of claim 44, wherein the second sensing element is temperature sensitive.

46. A gas sensor device adapted to detect target gas species in a gas environment, the gas sensor device including:

a first sensing element comprising a sensing wire supported by a plurality of metal posts, wherein the sensing wire has at least an outer surface consisting essentially of nickel or nickel alloy, is adapted to contact the gas environment, is adapted to interact with said target species in said gas environment, and is adapted to responsively exhibit a monitorable change in exposure to said target gas species, said monitorable change being correlative of concentration of said target gas species; and

a monitoring element operatively coupled with the first sensing element and adapted to generate a signal that varies in relation to concentration of said target gas species sensed by the first sensing element.

47. The gas sensor device of claim 46, wherein each post of the plurality of metal posts is sheathed with an insulating material.

48. The gas sensor device of claim 46, wherein at least two posts of the plurality of posts are in electrical contact with the sensing wire.

49. The gas sensor device of claim 46, wherein the sensing wire is woven between the plurality of posts.

50. The gas sensor device of claim 46, further comprising a polymeric support element supporting said plurality of posts.

51. The gas sensor device of claim 50, wherein the polymeric support element comprises any of a fluoro species-resistant polymer and a plasma-resistant polymer.

52. The gas sensor device of claim 50, wherein the polymeric support element comprises any of polyimide and polysulfone.

53. The gas sensor device of claim 46, further comprising a second sensing element.

54. The gas sensor device of claim 53, wherein the second sensing element is temperature sensitive.

55. The gas sensor device of claim 46, wherein said target gas species comprises a fluoro species.

56. The gas sensor device of claim 46, wherein at least an exterior layer of said sensing wire is composed of nickel.

57. The gas sensor device of claim 46, wherein said sensing wire consists essentially of nickel.

58. A method of improving the efficiency of a semiconductor manufacturing tool, the method comprising:

using the gas sensor device of claim 46 to sense at least one target gas species in a gas employed by, produced by, or constituting an ambient environment of the semiconductor manufacturing tool; and

adjusting runtime characteristics of the tool based on data generated from signals produced by the gas sensor device.

59. A method of monitoring a fluid locus for the presence of a target gas species therein, the method comprising:

exposing fluid at said fluid locus to the gas sensor device of claim 46;

monitoring the gas sensor device; and

responsively generating an output signal when the gas sensor device exhibits a response indicative of the presence or change of concentration of the target gas species in said fluid locus.

60. The method of claim 59, wherein the fluid locus comprises an ambient gas environment of a manufacturing process.

61. The method of claim 59, wherein the fluid locus comprises a fluid stream in a semiconductor processing plant.

62. The method of claim 59, wherein the target gas species comprises a fluoro species selected from the group consisting of NF₃, SiF₄, C₂F₆, HF, F₂, COF₂, ClF₃, IF₃, and activated species thereof.

63. The method of claim 59, further comprising communicating said output signal of the gas sensor device to any of a central processing unit, microprocessor, signal processing element, or signal-responsive element adapted to switch a process operation, terminate a process operation, or initiate a new process step or condition of a semiconductor manufacturing process tool.

64. A method comprising using data generated from signals produced by the gas sensor device of claim 46 in the manufacture of a semiconductor device.