THERMOCOUPLE

• US 20090308425A1
• Filed: 06/17/2008
• Published: 12/17/2009
• Est. Priority Date: 06/17/2008
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM America Incorporated (ASM International NV)
• Inventors: Yednak, Andy Michael III
• Granted Patent: US 7,946,762 B2
• Time in Patent Office: Days
• US Class Current: 136/230
• CPC Class Codes: G01K 13/00 Thermometers specially adapted for specific purposes
• CPC Class Codes: G01K 7/04 the object to be measured not forming one of the thermoelectric materials

Abstract

A thermocouple for use in a semiconductor processing reactor is described. The thermocouple includes a sheath having a measuring tip at one end and an opening at the other end. A support member having bores formed along the length is disposed within the sheath. A pair of wires formed of dissimilar metals are disposed within the bores, and one end of the wires is fused together to form a junction. The wires extend along the length of the bores. As the wires exit the bore, they are spatially or physically separated to prevent a short circuit therebetween. The ends of the wires exiting the bore are also free to thermally expand in the longitudinal manner, thereby reducing or eliminating the potential for the wires to fail due to grain slip.

Claims

1. A thermocouple for use in a semiconductor processing reactor, said thermocouple comprising:

a sheath having a measuring tip at an end thereof;

a support member disposed within said sheath, said support member having at least two bores formed therethrough;

a pair of wires formed of dissimilar metals, each of said pair of wires disposed within separate bores;

a junction formed between said pair of wires at an end of each wire, said junction being located adjacent to an end of said support member; and

wherein said pair of wires are able to freely thermally expand or contract relative to said support member.

2. The thermocouple of claim 1 further comprising a loop formed by each of said pair of wires as said pair of wires exit said corresponding bore.

3. The thermocouple of claim 2, wherein said loop has a radius of curvature greater than 2 mm.

4. The thermocouple of claim 1, wherein each of said pair of wires is covered by a protective tube as each of said pair of wires exits said corresponding bore.

5. The thermocouple of claim 4, wherein a portion of each of said pair of wires remains exposed as each of said pair of wires exits said corresponding bore.

6. The thermocouple of claim 5, wherein said exposed portion of each of said wires remains separated spatially or physically from the other of said exposed portion of each of said wires.

7. The thermocouple of claim 1, wherein said wires exiting said corresponding bores are separated by a portion of said support member located between said pair of wires.

8. The thermocouple of claim 1, wherein said wires exit said corresponding bore at a different distance relative to an end of said support member.

9. A thermocouple for use in a semiconductor processing reactor, said thermocouple comprising:

a sheath;

a support member at least partially disposed within said sheath, said support member having a first bore and a second bore formed substantially parallel to a longitudinal axis of said support member;

a first wire disposed within said first bore;

a second wire disposed within said second bore, said second wire formed of a dissimilar metal than said first wire;

a junction formed between an end of said first wire and an end of said second wire, wherein said junction is located adjacent to an end of said support member;

a first loop formed by a portion of said first wire adjacent to a location at which said first wire exits said first bore adjacent to an end of said support member opposite said junction; and

a second loop formed by a portion of said second wire adjacent to a location at which said second wire exits said second bore adjacent to an end of said support member opposite said junction;

wherein said first and second loops are configured to allow said first and second wires to freely thermally expand in a longitudinal manner within said support member.

10. The thermocouple of claim 9, wherein said first loop has a radius of curvature substantially equal to a radius of curvature of said second loop.

11. The thermocouple of claim 9, wherein said first loop has a radius of curvature different than a radius of curvature of said second loop.

12. The thermocouple of claim 9, wherein said radius of curvature of said first and second loops are at least 2 mm.

13. The thermocouple of claim 12, wherein said radius of curvature of said first and second loops are between 2 and 25 mm.

14. The thermocouple of claim 9 further comprising opposing cut-outs formed in said support member, said first wire exiting said first bore at an intersection between said first bore and one of said cut-outs and said second wire exiting said second bore at an intersection between said second bore and the other of said cut-outs.

15. The thermocouple of claim 14, wherein said intersection between said first bore and one of said cut-outs is spaced apart from an end of said support member a substantially equal distance as said intersection between said second bore and the other of said cut-outs.

16. The thermocouple of claim 14, wherein said intersection between said first bore and one of said cut-outs is spaced apart from an end of said support member a different distance as said intersection between said second bore and the other of said cut-outs.

17. The thermocouple of claim 9, wherein said first wire exits said first bore at substantially the same distance from an end of said support member as said second wire exits said second bore relative to said end of said support member.

18. The thermocouple of claim 9, wherein said first wire exits said first bore at a different distance from an end of said support member as said second wire exits said second bore relative to said end of said support member.

19. The thermocouple of claim 9 further comprising a cut-out formed into said support member that intersects with said first bore at a location spaced apart from an end of said support member such that said first bore extends less than the entire length of said support member, and said second bore extends the entire length of said support member.

20. The thermocouple of claim 9, wherein said first wire exits said first bore at a first location and said second wire exits said second bore at a second location, and said first location is spatially or physically separated from said second location to prevent a short circuit between said first and second wires.

21. A thermocouple for use in a semiconductor processing reactor, said thermocouple comprising:

a support member having at least one bore formed therein;

a first wire disposed within said first bore;

a second wire disposed adjacent to said first wire in a spaced apart manner, said second wire formed of a dissimilar metal than said first wire;

a junction formed between said first wire and said second wire;

a first loop formed by a portion of said first wire adjacent to an end of said support member extending from said sheath; and

a second loop formed by a portion of said second wire adjacent to said first loop;

wherein said first and second loops are configured to allow said first and second wires to freely thermally expand or contract relative to said support member.

22. The thermocouple of claim 21, wherein said support member includes a single bore formed therein.

23. The thermocouple of claim 22, wherein said second wire is disposed adjacent to an outer surface of said support member in a spaced-apart relationship relative to said first wire.

24. The thermocouple of claim 21, wherein said support member includes two bores formed therein.

25. The thermocouple of claim 21, wherein said support member includes four bores formed therein.

26. The thermocouple of claim 25 further comprising a third wire and a fourth wire, wherein each of said first, second, third, and fourth wires are received in separate bores and a second junction is formed between an end of each of said third and fourth wires.

27. The thermocouple of claim 21 further comprising at least three wires received within bores formed through said support member.

28. The thermocouple of claim 27 further comprising more than one junction formed between at least two of said at least three wires.