Apparatus for sensing temperature on a substrate in an integrated circuit fabrication tool

• US 6,190,040 B1
• Filed: 05/10/1999
• Issued: 02/20/2001
• Est. Priority Date: 05/10/1999
• Status: Active Grant

• Current Assignee: SensArray Corp. (KLA Corporation)
• Original Assignee: SensArray Corp. (KLA Corporation)
• Inventors: Renken, Wayne G., Sun, Mei H.
• Primary Examiner(s): Bennett, G. Bradley
• Assistant Examiner(s): VERBITSKY, GAIL KAPLAN
• Application Number:
  US09/307,667
• Time in Patent Office: 652 Days
• Field of Search: 374/208, 374/179, 374/183, 374/185, 374/133, 374/128, 374/126, 374/131
• US Class Current: 374/185
• CPC Class Codes: G01K 1/026 arrangements for monitoring a plurality of temperatures, e.g. by multiplexing
• CPC Class Codes: G01K 1/143 for measuring surface temperatures
• CPC Class Codes: H01L 21/67248 Temperature monitoring

Abstract

A cable and interconnect design including a substrate containing discrete sensors in a plurality of cavities or a plurality of thin film sensors deposited throughout the substrate surface. The discrete sensors are bonded within each cavity and potted with a potting compound. Each sensor has leads joined to filaments by an interconnect system. Thin film sensor leads on the substrate connect to a signal transmitting cable by the interconnect system. The filaments are coated and converge at a strain relief coupled to the substrate. The cable, having flat and round portions, includes an array of flat signal transmitting cables arranged side by side in the flat portion and stacked one on top of the other in the round portion. Each signal cable contains a plurality of the filaments bonded together. A pair of ribbons extend along the length of the array of cables. The ribbons and array of cables are bonded together with film to form the flat portion. The ribbons are joined to the strain relief, thereby joining the cable to the substrate. A boot is disposed around the cable transition between the flat and round portions. A connector is coupled to the round portion and the filaments are terminated to the connector. Advantages include the interconnect system bonding pads which reduce fabrication time and provide simple connection geometry on the substrate. Integration of the ribbons into the flat portion allows repeated use in a vacuum seal without damaging the cables. Stacked flat cables make identification of the filaments easy and product assembly fast.

Claims

1. An apparatus for sensing temperature on a substrate in an integrated circuit fabrication tool, comprising:

a substrate having a surface containing a plurality of small cavities thereon;

a plurality of sensors each bonded within a corresponding cavity of said substrate with an adhesive and potted with a potting compound, each of said sensors having sensor leads protruding through a potting layer formed by said potting compound;

an interconnect system joining at least one filament to each of said sensor leads, each of said filaments coated with a wall of insulating material for mechanical protection;

a strain relief structure coupled to a base of said substrate, said filaments converging at said strain relief structure;

a cable assembly having a flat cable portion, including;

(a) an array of flat signal transmitting cables arranged side by side, each of said signal transmitting cables formed by bonding a plurality of said filaments side by side with an adhesive;

(b) a pair of ribbons extending along the length of said array of signal transmitting cables, each on an opposed side thereof and held together with one or more sheets of film to form said flat cable portion having a first end and an opposed second end, said ribbons welded to a first side of said strain relief at said first end of the flat cable portion; and

(c) a protective boot disposed around said second end of the flat cable portion, said signal transmitting cables extending therethrough; and

a connector coupled to an end of the cable assembly and said filaments contained within the cable assembly terminated to said connector.

2. The apparatus of claim 1, wherein said cable assembly further includes:

a Y shaped component welded to the ribbons at the second end of the flat cable portion;

a tensile bearing member tied to the Y shaped component at the second end of the flat cable portion to prevent said signal transmitting cables from stretching under tension; and

a round cable portion between the protective boot and the connector, said signal transmitting cables extending therethrough.

3. The apparatus of claim 2, wherein said interconnect system further includes:

a plurality of bonding pads coated with an electrically conductive film and deposited on a thin insulative plate that is bonded to the surface of the substrate adjacent to each of said sensors with an adhesive, said sensor leads joined to a first side of each adjacent bonding pad and said filaments joined to a second side of said bonding pads opposite said first.

4. The apparatus of claim 3, wherein said strain relief structure is bonded to said substrate with an adhesive and stores excess filaments for rework and repair.

5. The apparatus of claim 3, wherein:

said ribbons are composed of hardened nickel to protect the signal transmitting cables in the flat cable portion when used under a vacuum seal and the ribbons have the necessary width and thickness to distribute the compression force such that the ribbons will not over-stress the vacuum seal and the flat cable will not be over-stressed by the vacuum seal;

said signal transmission cables are stacked at said second end of the flat cable portion, one on top of the other in a specific order and held together with a cable sleeve to maintain the order along said round cable portion for easy identification during termination to said connector;

at least one of said flat cable portion and said cable round cable portion is preformed to a specific shape and substantially returns to said shape each time an amount of tension applied to extend the cable is removed; and

said strain relief structure joined to said substrate by a pair of rivets instrumented into the substrate and containing excess filaments for rework or repair.

6. The apparatus of claim 5, wherein:

said substrate is instrumented such that said sensors form an axisymmetric pattern on the substrate to provide uniform density of the pattern on the substrate such that the uniformity of the emissivity of the substrate surface is optimized;

said bonding pad bonding adhesive is a polyimide;

said sensor bonding adhesive is a polyimide; and

said potting compound is silica coated aluminum nitride in a polyimide binder.

7. The apparatus of claim 6, wherein:

said tensile bearing member is Kevlar thread, a length of the tensile bearing member is slightly shorter than a length of the signal transmitting cables and a modulus of said tensile member is higher than a modulus of the signal transmitting cables; and

said adhesive used to bond together said plurality of filaments side by side to form each of said signal transmission cables is a polyimide.

8. The apparatus of claim 7, wherein:

said sensors are platinum resistive thermal detectors having a pair of sensor leads joined to a first side of the adjacent bonding pad;

said filaments are electrically conductive copper wires individually joined to a second side of one of said bonding pads opposite said first side and soldered to said connector; and

said wall of insulating material is polyimide.

9. The apparatus of claim 7, wherein:

said sensors are thermocouples having a pair of sensor leads connected to the filaments;

said filaments are thermocouple wires terminated to said connector; and

said wall of insulating material is polyimide.

10. The apparatus of claim 7, wherein:

said sensors are fiber optic;

said filaments are optical fibers.

11. The apparatus of claim 1, wherein said cable assembly further includes:

a Y shaped component welded to the ribbons at the second end of the flat cable portion;

a tensile bearing member tied to the Y shaped component at said second end of the flat cable portion to prevent said signal transmitting cable from stretching under tension;

a high temperature resistant area near the first end of the flat cable portion wherein a polyimide tubing surrounds said array of signal transmitting cables which are held together by a plurality of cross bars at said high temperature area of the flat cable portion; and

a round cable portion between the protective boot and the connector, said signal transmitting cables extending therethrough.

12. The apparatus of claim 11, wherein said interconnect system further includes:

a plurality of bonding pads coated made with an electrically conductive film and deposited on a thin insulative plate that is bonded to the surface of the substrate adjacent to each of said sensors with said adhesive, said sensor leads joined to a first side of each adjacent bonding pad and said filaments joined to a second side of said bonding pads opposite said first.

13. The apparatus of claim 12, wherein:

said strain relief structure is bonded to said substrate with an adhesive and stores excess filaments for rework and repair.

14. The apparatus of claim 12, wherein:

said ribbons are composed of hardened nickel to protect the signal transmitting cables in the flat cable portion when used under a vacuum seal and the ribbons have the necessary width and thickness to distribute the compression force such that the ribbons will not over-stress the vacuum seal and the flat cable will not be over-stressed by the vacuum seal;

said signal transmission cables are stacked at said second end of the flat cable portion, one on top of the other in a specific order and held together with a cable sleeve to maintain the order along said round cable portion for easy identification during termination to said connector;

at least one of said flat cable portion and said cable round cable portion is preformed to a specific shape and substantially returns to said shape each time an amount of tension applied to extend the cable is removed; and

said strain relief structure joined to said substrate by a pair of rivets instrumented into the substrate and containing excess filaments for rework or repair.

15. The apparatus of claim 14, wherein:

said substrate is instrumented such that said sensors form an axisymmetric pattern on the substrate to provide uniform density of the pattern on the substrate such that the uniformity of the emissivity of the substrate surface is optimized;

said bonding pad bonding adhesive is a polyimide;

said sensor bonding adhesive is a polyimide; and

said potting compound is silica coated aluminum nitride in a polyimide binder.

16. The apparatus of claim 15, wherein:

said tensile bearing member is Kevlar thread, a length of the tensile bearing member is slightly shorter than a length of the signal transmitting cables and a modulus of said tensile member is higher than a modulus of the signal transmitting cables; and

said adhesive used to bond together said plurality of filaments side by side to form each of said signal transmission cables is a polyimide.

17. The apparatus of claim 15, wherein:

said sensors are platinum resistive thermal detectors having a pair of sensor leads joined to a first side of the adjacent bonding pad;

said filaments are electrically conductive copper wires individually joined to a second side of one of said bonding pads opposite said first side and soldered to said connector; and

said wall of insulating material is polyimide.

18. The apparatus of claim 15, wherein:

said sensors are thermocouples having a pair of sensor leads being the filaments or connected to the filaments;

said filaments are thermocouple wires terminated to said connector.

19. The apparatus of claim 15, wherein:

said sensors are fiber optic;

said filaments are optical fibers; and

said wall of insulating material is polyimide.

20. The method of claim 1, further including the steps of:

(f) depositing a passivation film onto the substrate surface below the sensor and interconnect films; and

(g) depositing a protective coating over the instrumented substrate for use in wet processes.

21. A method of forming an apparatus for sensing temperature on a substrate in an integrated circuit fabrication tool, comprising the steps of:

(a) bonding together groups of the filaments side by side with polyimide to form a plurality of flat signal transmitting cables;

(b) stacking the flat signal cables individually one on top of the other in a specific order for easy identification of the filaments;

(c) feeding the stacked cables through a round cable sleeve, with a length of the flat cables protruding the round sleeve;

(d) disposing a protective boot over the cable with the wider end of the boot facing the protruded cables;

(e) aligning the flat signal transmitting cables side by side to form an array of flat signal cables near one end of the round sleeve;

(f) placing a pair of ribbons on each side of the array of flat signal cables;

(g) bonding the array of flat signal cables and ribbons in place with two sheets of film to form a flat cable portion of the cable having a first end and an opposed second end;

(h) coupling a connector to an end of the cable;

(i) terminating the filaments to the connector;

(j) creating a plurality of cavities on a surface of the substrate;

(k) disposing a sensor within each cavity;

(l) cementing each sensor within each cavity with an adhesive;

(m) potting each sensor with a potting compound;

(n) joining each sensor lead to at least one filament by an interconnect system;

(o) attaching a strain relief structure to the substrate; and

(p) welding the ribbons to the strain relief at a first end of the flat cable portion.

22. The method of claim 21, further comprising the steps of:

(q) covering the area near the first end of the flat cable portion with a polyimide sleeve to form a high temperature resistant area; and

(r) placing a plurality of cross-bars at predetermined intervals within the temperature resistant area.

23. An apparatus for sensing temperature on a substrate in an integrated circuit fabrication tool, comprising:

a substrate having a surface;

a plurality of interconnect conductor lines deposited and patterned onto the surface of said substrate with a metal film, said conductor lines intersecting at a plurality of conductor junctions;

an array of lead bonding pads deposited at an edge of the substrate and connected to said conductor lines;

an array of discrete bonding pads coupled to the substrate adjacent to said lead bonding pads and connected to said lead bonding pads; and

a plurality of thin film sensors having sensor leads deposited and patterned onto the surface of said substrate with a metal film, unwanted sensor leads are broken from the conductor lines during a sensor de-selection process, thereby providing an interconnection path only between the selected sensors and the pads.

24. The apparatus of claim 23, wherein:

said substrate is circular;

said conductor lines are formed in concentric circles with spokes radiating outward toward said edge of the substrate, thereby interconnecting said concentric circle conductor lines, said conductor lines intersecting at a plurality of conductor junctions; and

said sensors are deposited at selected locations on the substrate.

25. The apparatus of claim 23, wherein:

said substrate is rectangular; and

said conductor lines are formed in a rectangular grid shaped pattern, said conductor lines intersecting at a plurality of conductor junctions; and

said sensors are deposited at selected locations on the substrate.

26. The apparatus of claim 23, wherein:

said lead bonding pads and said discrete bonding pad are connected by a plurality of bond wires.

27. The apparatus of claim 23, wherein:

said lead bonding pads and said discrete bonding pads are connected by a plurality of ribbons.

28. The apparatus of claim 23, wherein:

said sensors are resistive thermal detectors and interconnected to three or more of said conductor lines.

29. The apparatus of claim 23, wherein:

said sensors are thermocouples and interconnected to two or more of said conductor lines.

30. The apparatus of claim 23, wherein the thin film instrumented substrate includes:

a protective coating encapsulating the substrate surface thereby allowing the instrumented thin film wafer to be used in wet processes.

31. The apparatus of claim 23, wherein said substrate further includes:

a passivating film is deposited onto the substrate surface below the interconnect and sensor films; and

said substrate is a semiconductor.

32. The apparatus of claim 23, wherein:

said substrate is glass.

33. A method of forming an apparatus for sensing temperature on a substrate in an integrated circuit fabrication tool, comprising the steps of:

(a) patterning a plurality of interconnect conductor lines onto a substrate surface with a metal film that is symmetrical and uniform;

(b) forming conductor junctions within the interconnect conductor lines;

(c) depositing an array of lead bonding pads along edges of the substrate;

(d) forming a plurality of thin film sensors having sensor leads on the surface of the substrate with a metal film at selected locations on the substrate; and

(e) deselecting the sensor leads of each unwanted sensor from the conductor lines, thereby providing an interconnection only path between the selected sensors and the pads.