Device for measuring pressure in a chamber

• US 6,279,402 B1
• Filed: 05/04/2000
• Issued: 08/28/2001
• Est. Priority Date: 08/10/1998
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Fisher, Paul
• Primary Examiner(s): OEN, WILLIAM L
• Application Number:
  US09/566,353
• Time in Patent Office: 481 Days
• Field of Search: 737/14, 737/15, 737/16, 737/17, 737/19, 737/20, 737/21, 737/22, 737/23, 737/25, 737/26, 737/27, 216/2, 216/33, 430/313, 430/314, 29/254.2, 296/211, 128/675, 156/631.1, 156/633.1, 156/647.1, 156/657.1, 156/662.1
• US Class Current: 73/754
• CPC Class Codes: C23C 16/45557 Pulsed pressure or control pressure
• CPC Class Codes: C23C 16/52 Controlling or regulating the coating process C23C16/45557, C23C16/279 take precedence
• CPC Class Codes: G01L 15/00 Devices or apparatus for measuring two or more fluid pressure values simultaneously
• CPC Class Codes: G01L 19/146 using flexible element between the transducer and the support
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: G01L 9/0054 integral with a semiconducting diaphragm
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details

Abstract

A device for measuring pressure at several locations in a processing chamber under dynamic conditions, i.e. when gas is flowing into and/or out of the chamber. A substrate has a plurality of pressure sensors electrically coupled to a measurement instrument. Conditions are established within a processing chamber to determine the effects of various process parameters, such as gas flow, on local pressures, and the local pressures are measured. The test conditions may simulate a process or may be standard test conditions to evaluate chamber configurations or hardware. The pressure test substrate may be calibrated under static conditions to improve the accuracy of the pressure readings.

Claims

1. An assembly for measuring pressure on a substrate comprising a reactor chamber for processing semiconductor wafers;

a substrate disposed in said reactor chamber;

a gas flowing into and out of said reactor chamber for assisting in producing a pressure on said substrate; and

at least one pressure sensor disposed on a surface of said substrate to provide at least one electrical signal in response to the pressure on the substrate.

2. The assembly of claim 1 wherein said at least one pressure sensor comprises a plurality of pressure sensors disposed on the surface of the substrate to provide a plurality of electrical signals in response to the pressure.

3. The assembly of claim 1 wherein the substrate is a silicon wafer.

4. The assembly of claim 2 wherein the silicon wafer has a diameter of at least about 150 mm.

5. The assembly of claim 1 wherein the substrate is a printed circuit board.

6. The assembly of claim 2 wherein the substrate has at least one pocket formed in the substrate and at least one of the plurality of pressure sensors is disposed in the pocket.

8. The assembly of claim 2 further comprising a plurality of conductive traces on the surface of the substrate, at least one of the plurality of conductive traces being electrically coupled to at least one of the pluality of pressure sensors.

9. The assembly of claim 8 wherein the plurality of conductive traces comprise a high-temperature conductor.

10. A The assembly of claim 9 wherein the high-temperature conductor comprises tungsten.

11. The assembly of claim 8 further comprising a ribbon cable, the ribbon cable having a plurality of wires, at least one of the plurality of wires being electrically coupled to as least one of the plurality of conductive traces.

12. The device of claim 1 wherein at least one of the plurality of sensors is a piezoresistive sensor.

13. The assembly of claim 2 wherein the substrate is a silicon wafer.

14. The assembly of claim 13 wherein the silicon wafer has a diameter of at least about 150 mm.

15. The assembly of claim 2 wherein the substrate is a printed circuit board.

16. The assembly of claim 1 wherein the substrate has at least one pocket formed in the substrate and said at least one pressure sensor is disposed in the pocket.

17. The assembly of claim 13 wherein the plurality of sensors is fabricated on the silicon wafer to form an integrated pressure test wafer.

18. The assembly of claim 1 further comprising a plurality of conductive traces on the surface of the substrate, at least one of the plurality of conductive traces being electrically coupled to said at least one pressure sensor.

19. The assembly of claim 18 wherein the plurality of conductive traces comprises a high-temperature conductor.

20. The assembly of claim 19 wherein the high-temperature conductor comprises tungsten.

21. The assembly of claim 18 further comprising a ribbon cable, the ribbon cable having a plurality of wires, at least one of the plurality of wires being electrically coupled to at least one of the plurality of conductive traces.

22. The assembly of claim 1 wherein said at least one of the pressure sensor is a piezoresistive sensor.

23. The assembly of claim 1 additionally comprising a wire coupled to said at least one pressure sensor.

24. The assembly of claim 23 wherein said wire extends out of said reactor chamber.

37. The device of claim 1 wherein said substrate comprises a temperature above about 150°

C.

38. The device of claim 2 wherein said substrate comprises a temperature above about 450°

C.

7. The assembly of 3 wherein the at least one pressure sensor is fabricated on the silicon wafer to form an integrated pressure test wafer.

25. A device for measuring pressure in a chamber comprising a substrate having a substrate surface and including a structure defining a cavity;

a chip pressure sensor disposed in said cavity; and

at least one conductive trace disposed on said substrate surface and electrically coupled to said chip pressure sensor.

26. The device of claim 25 wherein said chip pressure sensor includes a top planar surface which is generally aligned with said substrate surface.

27. The device of claim 25 wherein said conductive trace comprises a first metal layer bound to said substrate surface and a second metal layer disposed on said first metal layer.

28. The device of claim 26 wherein said conductive trace comprises a first metal layer bound to said substrate surface and a second metal layer disposed on said first metal layer.

29. The device of claim 25 additionally comprising a reactor chamber containing said substrate.

30. The device of claim 28 additionally comprising a reactor chamber containing said substrate.

31. The device of claim 29 additionally comprising a gas flowing through said reactor chamber and contacting said substrate.

32. The device of claim 30 additionally comprising a gas flowing through said reactor chamber and contacting said substrate.

33. The device of claim 25 wherein said substrate comprises a temperature above about 150°

C.

34. The device of claim 32 wherein said substrate comprises a temperature above about 150°

C.

35. The device of claim 25 wherein said substrate comprises a temperature above about 450°

C.

36. The device of claim 27 wherein said substrate comprises a temperature above about 450°

C.

45. The integrated test wafer of claim 34 wherein said silicon substrate comprises a defect density greater than about 0.15/cm²>

0.2 μ

.

39. An integrated test wafer for measuring pressure in a processing chamber comprising a substrate having a substrate surface and including a substrate structure with no flexible diaphragm;

a plurality of pressure sensors integrally formed in said substrate and in proximity to said substrate surface such as to be exposed for measuring pressure in a reactor chamber; and

a conductive trace disposed on said substrate surface.

40. The integrated test wafer of claim 39 wherein said pressure sensors include at least one high-temperature metallization layer.

41. The integrated test wafer of claim 39 wherein each of said pressure sensors include a thin-film resistor coupled to said conductive trace.

42. The integrated test wafer of claim 40 wherein each of said pressure sensors include a thin-film resistor coupled to said conductive trace.

43. The integrated test wafer of claim 39 wherein said silicon substrate comprises a temperature above about 150°

C.

44. The integrated test wafer of claim 42 wherein said silicon substrate comprises a temperature above about 450°

C.

46. Device for measuring pressure in a chamber comprising a substrate having a substrate surface and a structure defining a cavity;

a first diaphragm layer supported by said substrate layer and extending over said cavity;

a second diaphragm layer supported by said first diaphragm layer;

at least one thin-film resistor supported by said second diaphragm layer; and

at least one conductive trace supported by said substrate surface and coupled to said at least one thin-film resistor.

47. The device of claim 46 wherein said substrate comprises said structure additionally having a ledge.

48. The device of claim 46 additionally comprising a dielectric layer supported by said second diaphragm layer and disposed between said thin-film resistor and said second diaphragm layer.

49. The device of claim 47 additionally comprising a dielectric layer supported by said second diaphragm layer and disposed between said thin-film resistor and said second diaphragm layer.

50. The device of claim 47 wherein said first diaphragm layer has an opening wherethrough a portion of the second diaphragm layer extends for contacting and being supported by said ledge.

51. The device of claim 49 wherein said first diaphragm layer has an opening wherethrough a portion of the second diaphragm layer extends for contacting and being supported by said ledge.

52. The device of claim 46 additionally comprising a barrier layer supported by said second diaphragm layer.

53. The device of claim 52 wherein said at least one thin-film resistor comprises four interconnected thin-film resistors forming four corners, and said at least one conductive trace comprises four conductive traces coupled to said four interconnected thin-film in resistors at said four corners.