Method and apparatus for protecting wiring and integrated circuit device

• US 6,809,384 B1
• Filed: 08/09/2002
• Issued: 10/26/2004
• Est. Priority Date: 08/09/2002
• Status: Active Grant

• Current Assignee: Altera Corporation (Intel Corporation)
• Original Assignee: PTS Corporation
• Inventors: Reyes, David, Anderson, Robert L.
• Primary Examiner(s): GHYKA, ALEXANDER G
• Application Number:
  US10/216,600
• Time in Patent Office: 809 Days
• Field of Search: 257/355, 257/522, 257/254
• US Class Current: 257/355
• CPC Class Codes: B81B 7/0012 Protection against reverse engineering, unauthorised use, use in unintended manner, wrong insertion or pin assignment
• CPC Class Codes: H01L 23/5225 Shielding layers formed together with wiring layers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A method and apparatus for protecting a conductor in an integrated circuit. A protective covering can be disposed over a conductor for a substantial length along the conductor while allowing a portion of the conductor to be exposed. The protective covering can be configured as a tunnel which runs for a substantial length along the conductor and can be operable to prevent the occurrence of electrical shorts during operation of the integrated circuit. According to one embodiment of the invention the integrated circuit can be configured as a micromachined device with active mechanical components exposed to the atmosphere.

Claims

1. A micromachined device comprising:

a substrate;

a conductor configured as part of said micromachined device;

a protective covering disposed over said conductor so that said conductor is disposed between said substrate and said protective covering; and

wherein said protective covering is configured so as to form a tunnel relative to said conductor.

2. The device as described in claim 1 wherein said protective covering comprises polysilicon.

3. The device as described in claim 1 wherein said protective covering is deposited as a layer of material.

4. The device as described in claim 3 wherein said layer of material protects a plurality of conductors.

5. The device as described in claim 1 wherein said protective covering is electrically coupled with said substrate so as to form a ground ring around said conductor.

6. The device as described in claim 1 wherein said device is configured for operation without a passivation layer disposed over said conductor.

7. A micromachined apparatus comprising:

a substrate;

a bonding pad;

a conductor disposed over said substrate, wherein said conductor is electrically coupled with said bonding pad;

an active mechanical component disposed over said substrate, wherein said active mechanical component is configured to move relative to said substrate;

a protective cover disposed over said conductor so that said conductor is disposed between said protective cover and said substrate;

wherein said protective layer of material is configured so as to form a tunnel relative to said conductor.

8. The apparatus as described in claim 7 wherein said active mechanical component comprises a mirror.

9. The apparatus as described in claim 8 wherein said mirror comprises silicon.

10. The apparatus as described in claim 7 wherein said active mechanical component is exposed to the atmosphere during operation of said apparatus.

11. The apparatus as described in claim 7 wherein a portion of said conductor is exposed to the atmosphere during operation of said apparatus.

12. The apparatus as described in claim 7 wherein said protective cover comprises an polysilicon.

13. The apparatus as described in claim 7 wherein said protective layer of material is operable to protect said conductor from an electrical short when a voltage of at least 100 Volts is applied to said protective layer of material.

14. The apparatus as described in claim 7 wherein said protective layer of material is configured so as to form a ground ring with said substrate around said conductor.

15. The apparatus as described in claim 7 wherein said apparatus is configured for operation without depositing a passivation layer.

16. A micromachined apparatus comprising:

a bonding pad;

an active mechanical component configured to move during operation of said micromachined apparatus;

a conductor disposed between said active mechanical component and said bonding pad;

a covering configured so as to protect at least a portion of said conductor disposed between said bonding pad and said active mechanical component from electrical shorts;

wherein said covering is configured so as to form a tunnel relative to said conductor.

17. The micromachined apparatus as described in claim 16 wherein said active mechanical component comprises a mirror.

18. The micromachined apparatus as described in claim 16 wherein a portion of said conductor is exposed to the atmosphere during operation of said micromachined apparatus.

19. The micromachined apparatus as described in claim 16 wherein said covering is configured so as to protect said conductor when a voltage of at least 100 Volts is applied to said covering.

20. The micromachined apparatus as described in claim 16 wherein said covering is configured so as to form at least part of a ground ring around said conductor.

21. The micromachined apparatus as described in claim 16 wherein said micromachined apparatus is configured without depositing a passivation layer.

22. An apparatus comprising:

a substrate;

a conductor disposed over said substrate, said conductor operable for conducting electrical signals;

an equipotential barrier disposed at least partially around said conductor and operable for protecting said conductor from electrical shorts;

wherein said equipotential barrier comprises a conductive material configured as a tunnel over said conductor; and

wherein said conductive material is electrically coupled with said substrate.

23. The apparatus as described in claim 22 wherein said equipotential barrier comprises polysilicon;

and

wherein said polysilicon is electrically coupled with said substrate so as to form an equipotential ring.

24. The apparatus as described in claim 23 wherein said equipotential ring is configured for coupling to a circuit ground during operation of said apparatus.

25. The apparatus as described in claim 24 wherein said equipotential barrier is configured for coupling to a circuit ground during operation of said apparatus.

26. A micromachined device comprising:

a substrate;

a conductor configured as part of said micromachined device;

a protective covering disposed over said conductor so that said conductor is disposed between said substrate and said protective covering; and

wherein said protective covering is electrically coupled with said substrate so as to form a ground ring around said conductor.

27. The device as described in claim 26 wherein said protective covering comprises polysilicon.

28. The device as described in claim 26 wherein said protective covering is deposited as a layer of material.

29. The device as described in claim 28 wherein said layer of material protects a plurality of conductors.

30. The device as described in claim 26 wherein said device is configured for operation without a passivation layer disposed over said conductor.

31. A micromachined apparatus comprising:

a substrate;

a bonding pad;

a conductor disposed over said substrate, wherein said conductor is electrically coupled with said bonding pad;

an active mechanical component disposed over said substrate, wherein said active mechanical component is configured to move relative to said substrate;

a protective cover disposed over said conductor so that said conductor is disposed between said protective cover and said substrate;

wherein said protective layer of material is configured so as to form a ground ring with said substrate around said conductor.

32. The apparatus as described in claim 31 wherein said active mechanical component comprises a mirror.

33. The apparatus as described in claim 32 wherein said mirror comprises silicon.

34. The apparatus as described in claim 31 wherein said active mechanical component is exposed to the atmosphere during operation of said apparatus.

35. The apparatus as described in claim 31 wherein a portion of said conductor is exposed to the atmosphere during operation of said apparatus.

36. The apparatus as described in claim 31 wherein said protective cover comprises polysilicon.

37. The apparatus as described in claim 31 wherein said protective layer of material is operable to protect said conductor from an electrical short when a voltage of at least 100 Volts is applied to said protective layer of material.

38. The apparatus as described in claim 31 wherein said apparatus is configured for operation without depositing a passivation layer.

39. A micromachined apparatus comprising:

a bonding pad;

an active mechanical component configured to move during operation of said micromachined apparatus;

a conductor disposed between said active mechanical component and said bonding pad;

a covering configured so as to protect at least a portion of said conductor disposed between said bonding pad and said active mechanical component from electrical shorts;

wherein said covering is configured so as to form at least part of a ground ring around said conductor.

40. The micromachined apparatus as described in claim 39 wherein said active mechanical component comprises a mirror.

41. The micromachined apparatus as described in claim 39 wherein a portion of said conductor is exposed to the atmosphere during operation of said micromachined apparatus.

42. The micromachined apparatus as described in claim 39 wherein said covering is configured so as to protect said conductor when a voltage of at least 100 Volts is applied to said covering.

43. The micromachined apparatus as described in claim 39 wherein said micromachined apparatus is configured without depositing a passivation layer.