Wafer probe station

• US 20020118009A1
• Filed: 04/29/2002
• Published: 08/29/2002
• Est. Priority Date: 07/13/2000
• Status: Active Grant

• Current Assignee: Silicon Valley Bank (SVB Financial Group)
• Original Assignee: The Micromanipulator Company Incorporated (FormFactor Incorporated)
• Inventors: Harrison, Daniel L., Hollman, Kenneth F.
• Granted Patent: US 6,803,756 B2
• Time in Patent Office: Days
• US Class Current: 324/158.1
• CPC Class Codes: G01R 1/025 concerning dedicated user interfaces, e.g. GUI, or dedicated keyboards G01R31/31912 takes precedence
• CPC Class Codes: G01R 1/18 Screening arrangements against electric or magnetic fields, e.g. against earth's field
• CPC Class Codes: G01R 31/281 Specific types of tests or tests for a specific type of fault, e.g. thermal mapping, shorts testing G01R31/2818 takes precedence
• CPC Class Codes: G01R 31/2851 Testing of integrated circuits [IC] G01R31/317 takes precedence; testing individual devices G01R31/26; testing printed circuits G01R31/2801
• CPC Class Codes: G01R 31/2886 Features relating to contacting the IC under test, e.g. probe heads; chucks G01R31/2865 takes precedence, test connections, e.g. test sockets, or probes per se, G01R1/04 or G01R1/06
• CPC Class Codes: G01R 31/2889 Interfaces, e.g. between probe and tester G01R31/31905 and G01R1/07364 take precedence

Abstract

The invention relates to a chuck apparatus for a wafer probe station in which the central conductive surface supports a device-under-test (DUT) over a conductive lower chuck portion. An insulator positions the center conductor surface of the chuck above the lower chuck portion and also positions an electrically isolated conductor along its periphery. A laterally extending shielding element is provided for shielding electromagnetic interference (ENI) from the center conductor surface and the lower chuck portion. The electrically isolated conductor and the conductive lower chuck portion max cooperate to form a line-of-sight electrical barrier between the center conductor surface and the laterally extending shielding element. The invention further relates to methods of manufacturing the chuck apparatus and using the apparatus to accomplish low current and voltage tests in a probe station.

Claims

1. A chuck apparatus for a wafer probe station, comprising:

a laterally extending electrical insulator having an upper surface;

a first conductive member disposed on the upper surface of said insulator for supporting a wafer device under test, said insulator supported on a second conductive member, the outer edge of the first conductive member being spaced from the outer edge of the insulator;

a third conductive member isolated from and spaced below said second conductive member; and

an electrically isolated fourth conductive member disposed on the upper surface of said insulator in spaced relation to the outer edge of said first conductive member.

2. The chuck, apparatus recited in claim 1, wherein said second and fourth conductive members form an electrical barrier between said first conductive member and said third conductive member.

3. A chuck apparatus a, recited in claim 1, wherein said second conductive member comprises one or more temperature control elements enclosed therein.

4. The chuck apparatus recited in claim 1, wherein said third conductive member has a laterally extending portion and a portion extending vertically, opposite the side surface of the second conductive member.

5. A chuck apparatus as recited in claim 1, wherein the area of the upper surface of said laterally, extending, electrical insulator is larger than the area of the upper surface of said first conductive member disposed thereon.

6. A chuck apparatus as recited in claim 1, wherein said fourth conductive member is at the periphery of said insulator.

7. A chuck apparatus as recited in claim 6, wherein said fourth conductive member extends vertically along the sides of the insulator.

8. A chuck apparatus as recited in claim 1, wherein said first and second conductive members and said insulator each have a circular upper surface and said fourth conductive member comprises a ring concentric with said first conductive member.

9. A chuck apparatus as recited in claim 8, wherein the diameter of said insulator is larger than the diameter of said second conductive member.

10. A chuck apparatus as recited in claim 9, wherein said fourth conductive member extends vertically along the sides of the insulator and laterally along at least a portion of the bottom surface of the insulator.

11. A chuck apparatus as recited in claim 8, wherein the diameter of said insulator is the same as the diameter of said second conductive member.

12. A chuck apparatus as recited in claim 1, wherein said second, third and fourth conductive members are adapted for coupling to electric potentials.

13. A chuck apparatus as recited in claim 12, wherein said second and fourth conductive members are adapted for being coupled to a coaxial cable assembly for providing electric potentials, and said third conductive member is adapted for being coupled to an electric ground potential.

14. A chuck apparatus as recited in claim 12, wherein said second, third and fourth conductive members are adapted for being coupled to a triaxial cable assembly for providing electric potentials.

15. A chuck apparatus as recited in claim 12, wherein said second and fourth conductive members are raised to substantially the same electric potential as said first conductive member to reduce the effects of capacitance and noise at said device under test.

16. A chuck apparatus as recited in claim 1, wherein said second and fourth conductive members form a line-of-sight electrical barrier between said first conductive member and said third conductive member to reduce parasitic capacitance.

17. A chuck apparatus as recited in claim 4, wherein the vertically extending portion of said third conductive member terminates below the first conductive member.

18. A chuck apparatus as recited in claim 4, wherein the vertically extending portion of said third conductive member terminates below the insulator.

19. A chuck apparatus as recited in claim 1, wherein said second conductive element includes a central recess in its upper surface and said insulator includes a thicker central portion adapted to mate with said recess.

20. A chuck apparatus as recited in claim 1, wherein the upper surface of said first conductive member lies in a horizontal plane above the upper surface of said insulator.

21. A chuck apparatus as recited in claim 1, wherein the first conductive member is disposed in a recess in said insulator such hat the upper surface of said first conductive member lies in a horizontal plane below the upper surface of said insulator.

22. A chuck apparatus as recited in claim 1, wherein said the first conductive member is disposed in a recess in said insulator such that the upper surface of said first conductive member and said upper surface of said insulator lie in the same horizontal plane.

23. A chuck apparatus as recited in claim 1, wherein the fourth conductive member is disposed in a groove in said insulator such that the upper surface of the fourth conductive member and the upper surface of the first conductive member lie in the same horizontal plane.

24. The chuck apparatus as recited in claim 1, wherein the fourth conductive member is disposed in a groove in said insulator such that the upper surface of the fourth conductive member lies in a horizontal plane below the upper surface of the first conductive member.

26. A method as recited in claim 25, wherein said second and fourth conductive elements are held at the same electric potential.

27. The method of claim 25, wherein at least one of said second and fourth conductive elements are held at substantially the same electric potential as the first conductive element.

28. The method of claim 25, wherein said third conductive element is connected to ground potential.

29. The method of claim 25, wherein said probe station includes conductive surfaces, and at least one of said surfaces is connected to ground potential.

25. A method for inspecting a device under test in a probe station, the method comprising:

providing a chuck apparatus for supporting the device under test, the chuck apparatus comprising;

a laterally extending insulator having an upper surface,

a first conductive element disposed on said upper surface of said insulator adapted for electrical contact with said device under test,

a laterally extending second conductive element disposed belong said insulator,

a laterally extending third conductive element disposed below and electrically isolated from said second conductive element and having a portion at its periphery extending vertically opposite the sides of said second conductive element and

a fourth conductive element disposed on said insulator, said fourth conductive element laterally surrounding and electrically isolated from said first conductive element;

applying an electric potential to said first conductive element and to at least one of said second, third and fourth conductive elements.

30. A method of manufacturing a chuck apparatus for a wafer probe station, the method comprising:

depositing a first amount of conductive material on an insulator plate comprising an electrical insulator material to form a conductive test area;

depositing a second amount of conductive material on the insulator plate spaced from and laterally surrounding the conductive test area to form an electrically isolated conductive element,

supporting said insulator plate on a conductive support,

attaching and electrically isolating a further conductor spaced below, said conductive support, and

adapting the conductive test area, isolated conductive element, conductive support, and further conductor for being coupled to electrical potentials.

31. A method as recited in claim 30, wherein the insulator plate comprises a ceramic substrate and the conductive test surface and the electrically isolated conductive element are formed thereon, thereby fixing the alignment between the conductive test area and the electrically isolated conductive element.

32. A method as recited in claim 30, wherein the conductive test area and the electrically isolated conductive element are deposited onto the insulator plate by plasma discharge sputtering.

33. A method as recited in claim 30, further comprising depositing the second amount of conductive material on the top surface along the periphery, on the lateral edges, and on the bottom surface along the periphery of the insulator plate.

34. A method as recited in claim 30, further comprising providing a central recess in the upper surface of said insulator plate and depositing said first conductive material for said test area in said recess.

35. A method as recited in claim 30, further comprising providing a groove at the periphery of the upper surface of said insulator plate and depositing said second conductive material for said isolated conductive element in said groove.

36. A probe station for inspecting a device under test comprising:

a frame having, opposite vertically disposed supports,

a horizontally extending platen supported on said frame

a chuck apparatus for supporting the device under test positioned as within said frame, and

a holder supported on said platen for holding a probe for contacting said device under test,

said chuck apparatus further comprising;

a laterally extending electrical insulator having an upper surface;

a first conductive member disposed on the upper surface of said insulator for supporting a wafer device under test, said insulator supported on a second conductive member, the outer edge of the first conductive member being spaced from the outer edge of the insulator;

a third conductive member isolated from and spaced below said second conductive member; and

an electrically isolated fourth conductive member disposed on the upper surface of said insulator in spaced relation to the outer edge of said first conductive member.

37. A chuck apparatus for a wafer probe station, comprising:

a laterally extending electrical insulator having an upper surface;

a first conductive member disposed on the upper surface of said insulator for supporting a wafer device under test;

said insulator supported on a second conductive member; and

a third conductive member isolated from said second conductive member and having a laterally extending portion spaced below said second conductive element and a vertically extending sidewall terminating opposite said second conductive member.