THERMOCOUPLE ASSEMBLY WITH GUARDED THERMOCOUPLE JUNCTION

• US 20100282163A1
• Filed: 05/06/2009
• Published: 11/11/2010
• Est. Priority Date: 05/06/2009
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM America Incorporated (ASM International NV)
• Inventors: Haro, Robert C., Aggarwal, Ravinder K.
• Granted Patent: US 8,382,370 B2
• Time in Patent Office: Days
• US Class Current: 118/666
• CPC Class Codes: G01K 7/02 using thermoelectric elements, e.g. thermocouples
• CPC Class Codes: G01K 7/04 the object to be measured not forming one of the thermoelectric materials

Abstract

An improved thermocouple assembly for providing a temperature measurement is provided. The thermocouple assembly includes a sheath having a measuring tip, a support member received within the sheath, and first and second wires disposed within the support member. An end of each of the first and second wires are fused together to form a thermocouple junction therebetween. A recessed region is formed in a distal end of the support member, and the thermocouple junction is fixedly located at the base of the recessed region such that the recessed region maintains the thermocouple junction in a substantially fixed position relative to the measuring tip of the sheath.

Claims

1. A thermocouple assembly for measuring temperature within a chemical vapor deposition reactor, said thermocouple assembly comprising:

a sheath having a measuring tip located at a distal end of said sheath;

a support member, wherein at least a portion of said support member is received within said sheath;

a first wire and a second wire formed of dissimilar metals, a portion of said first and second wires received within said support member, and an end of each of said first and second wires being fused together to form a thermocouple junction therebetween; and

a recessed region formed in a distal end of said support member, wherein distal end of said support member contacts said sheath, and said thermocouple junction is located immediately adjacent to a base of said recessed region.

2. The thermocouple assembly of claim 1, wherein said thermocouple junction is positioned at a fixed spaced-apart distance from said measuring tip of said sheath.

3. The thermocouple assembly of claim 2, wherein said fixed spaced-apart distance between said thermocouple junction and said measuring tip of said sheath is less than 5 mm.

4. The thermocouple assembly of claim 2, wherein said fixed spaced-apart distance between said thermocouple junction and said measuring tip of said sheath is less than 1 mm.

5. The thermocouple assembly of claim 1, wherein said thermocouple junction is in contact with said measuring tip of said sheath.

6. The thermocouple assembly of claim 1, wherein an edge is formed about said recessed region at said distal end of said support member.

7. The thermocouple assembly of claim 6, wherein said edge is a ledge extending in a substantially perpendicular manner relative to a longitudinal axis of said support member.

8. The thermocouple assembly of claim 6, wherein said edge contacts an inner surface of said sheath at said measuring tip.

9. The thermocouple assembly of claim 1, wherein said thermocouple junction is maintained at a substantially fixed location relative to said base of said recessed region.

10. The thermocouple assembly of claim 1 further comprising a side wall formed about said recessed region, wherein said side wall guards said thermocouple junction.

11. The thermocouple assembly of claim 1, wherein said recessed region forms a substantially semi-spherical indentation.

12. The thermocouple assembly of claim 1, wherein said recessed region forms a substantially cylindrical indentation.

13. The thermocouple assembly of claim 1, wherein said recessed region forms a truncated conical indentation.

14. The thermocouple assembly of claim 1, wherein said recessed region forms a conical indentation.

15. The thermocouple assembly of claim 1, wherein said first wire is formed of Platinum and said second wire is formed/of a Platinum alloy containing about 13% Rhodium.

16. A thermocouple assembly for measuring temperature within a chemical vapor deposition reactor, said thermocouple assembly comprising:

an elongated support member, said support member configured to receive at least a portion of said first wire and a second wire therewithin, wherein said first wire and second wire are formed of dissimilar metals;

an elongated sheath having a measuring tip, said sheath configured to receive said support member such that a distal end of said support member contacts an inner surface of said sheath at said measuring tip;

a thermocouple junction formed by fusing an end of each of said first and second wires; and

a recessed region formed into said distal end of said support member, wherein said thermocouple junction is maintained at a substantially fixed position relative to said measuring tip of said sheath.

17. A temperature control system for use in a semiconductor processing reactor comprising:

at least one heating element located within said reactor;

a controller operatively connected to said at least one heating element, said controller configured to control said at least one heating element; and

at least one temperature sensor located within said reactor, said at least one temperature sensor operatively connected to said controller for providing temperature data to said controller, wherein said at least one temperature sensor comprises a thermocouple assembly, said thermocouple assembly comprising;

a sheath having a measuring tip located at a distal end of said sheath;

a support member, wherein at least a portion of said support member is received within said sheath;

a first wire and a second wire formed of dissimilar metals, a portion of said first and second wires received within said support member, and an end of each of said first and second wires being fused together to form a thermocouple junction therebetween; and

a recessed region formed in a distal end of said support member, and said distal end of said support member contacts said measuring tip of said sheath, wherein said thermocouple junction is located at a substantially fixed position relative to said measuring tip of said sheath.

18. The temperature control system of claim 17, wherein said recessed region forms a side wall that surrounds said thermocouple junction, thereby guarding said thermocouple junction from direct radiant energy from said at least one heating element.

19. The temperature control system of claim 17, wherein said recessed region is formed as a substantially semi-spherical indentation in said distal end of said support member.

20. The temperature control system of claim 17, wherein said recessed region is formed as a substantially cylindrical indentation in said distal end of said support member.

21. The temperature control system of claim 17, wherein said recessed region is formed as a planar surface, said planar surface being oriented at an angle relative to a longitudinal axis of said support member.

22. The temperature control system of claim 17 further comprising an edge formed about said recessed region at said distal end of said support member, and said edge contacts an inner surface of said sheath to provide said spaced apart distance between said thermocouple junction and said measuring tip.