Thermal optical chuck

• US 7,504,823 B2
• Filed: 12/01/2006
• Issued: 03/17/2009
• Est. Priority Date: 06/07/2004
• Status: Expired due to Fees

• Current Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Original Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Inventors: Rumbaugh, Scott
• Primary Examiner(s): Nguyen; Ha Tran T
• Assistant Examiner(s): Nguyen; Tung X
• Application Number:
  US11/607,331
• Publication Number:
  US 20070075724A1
• Time in Patent Office: 837 Days
• Field of Search: 324/754, 324761-762, 324/765, 324/760, 324757-758, 324752-753, 356/479, 356/497, 356/239.1
• US Class Current: 324/750.03
• CPC Class Codes: G01R 1/0458 related to environmental aspects, e.g. temperature
• CPC Class Codes: G01R 31/286 External aspects, e.g. related to chambers, contacting devices or handlers
• CPC Class Codes: G01R 31/2891 related to sensing or controlling of force, position, temperature G01R31/2874 takes precedence; sensing of force G01L; sensing of position G01B, G01D; sensing of temperature G01K; controlling in general G05

Abstract

An accessible optical path to a lower surface of a heatable device under test is provided by a thermal optical chuck comprising a transparent resistor deposited on transparent plate arranged to supporting the device in a probe station.

Claims

1. A thermal optical chuck for supporting a device under test in a probe station, said thermal optical chuck comprising:

(a) a rectangular transparent conductor having a resistance and arranged proximate a surface of said device under test;

(b) a first bus bar in conductive contact with said rectangular transparent conductor at a location nearer a first edge of said conductor than a second edge of said conductor, said first bus bar being connectible to a source of electric current; and

(c) a second bus bar in conductive contact with said transparent conductor at a location nearer said second edge of said conductor than said first edge, said second bus bar being connectible to said source of electric current and spaced apart from said first bus bar.

2. The thermal optical chuck of claim 1 wherein said transparent conductor comprises indium tin oxide.

3. The thermal optical chuck of claim 1 wherein said transparent conductor comprises silver zinc oxide.

4. The thermal optical chuck of claim 1 wherein said transparent conductor comprises antimony tin oxide.

5. The thermal optical chuck of claim 1 wherein said transparent conductor comprises a conductive polymer.

6. The thermal optical chuck of claim 5 wherein said conductive polymer comprises poly(ethylenedioxythiophene).

7. The thermal optical chuck of claim 5 wherein said conductive polymer comprises polyaniline.

8. The thermal optical chuck of claim 1 wherein said rectangular transparent conductor is supported on a surface of a transparent plate, said transparent plate supporting said device under test.

9. The thermal optical chuck of claim 8 wherein said transparent plate comprises fused silica.

10. The thermal optical chuck of claim 8 wherein said transparent plate comprises quartz.

11. The thermal optical chuck of claim 8 wherein said transparent plate comprises sapphire.

12. The thermal optical chuck of claim 8 wherein said transparent plate comprises lithium niobate.

13. The thermal optical chuck of claim 8 wherein said transparent plate comprises glass.

14. The thermal optical chuck of claim 1 wherein said rectangular transparent conductor comprises a square transparent conductor.

15. The thermal optical chuck of claim 1 wherein said second bus bar includes a length arranged substantially parallel to a portion of said first bus bar.

16. The thermal optical chuck of claim 1 further comprising:

(a) a base; and

(b) a support maintaining said base and said rectangular transparent conductor in a spaced relationship.

17. The thermal optical chuck of claim 1 further comprising:

(a) a frame having portions defining a first aperture circumscribing a substantial area of said rectangular transparent conductor and a second aperture being connectible to a vacuum source; and

(b) a clamp including a first surface arranged to engage a surface of a device under test and a second surface arranged to block a flow of air to said second aperture when said second aperture is connected to a vacuum source, said clamp securing a surface of said device under test proximate said rectangular transparent conductor when said first surface is in engagement with said device under test and said second surface is blocking said flow of air to said second aperture.

18. A thermal optical chuck for supporting a device under test in a probe station, said thermal optical chuck comprising:

(a) a base;

(b) a transparent plate having a first surface for supporting said device under test and an opposing second surface;

(c) a support spacing apart said base and said transparent plate;

(d) a transparent conductor having a resistance, said transparent conductor being deposited over a rectangular area of said second surface of said transparent plate, said rectangular area being defined by a first edge and a spaced apart second edge;

(e) a first bus bar in conductive contact with said transparent conductor proximate said first edge, said first bus bar being connectible to a source of electric current; and

(f) a second bus bar in conductive contact with said transparent conductor proximate said second edge, said second bus bar being connectible to said source of electric current.

19. The thermal optical chuck of claim 18 wherein said transparent plate comprises at least one of glass, sapphire, fused silica, quartz, and lithium niobate.

20. The thermal optical chuck of claim 18 wherein said transparent conductor comprises one of indium tin oxide, silver zinc oxide, antimony tin oxide, and a conductive polymer.

21. The thermal optical chuck of claim 18 further comprising:

(a) a frame adjacent to said edge of said transparent plate, said frame including a surface having portions defining an aperture, said aperture being connectible to a vacuum source; and

(b) a clamp including a first surface arranged to engage an upper surface of a device under test supported by said transparent plate and a second surface arranged to block a flow of air to said aperture when said first surface is engaged with said upper surface of said device under test and said aperture is connected to a vacuum source.