LOCAL MULTILAYERED METALLIZATION

• US 20060199387A1
• Filed: 05/24/2006
• Published: 09/07/2006
• Est. Priority Date: 09/02/1999
• Status: Abandoned Application

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Rhodes, Howard E.
• Application Number:
  US11/420,101
• Publication Number:
  US 20060199387A1
• Time in Patent Office: Days
• US Class Current: 438/687
• CPC Class Codes: H01L 21/76816 Aspects relating to the layout of the pattern or to the size of vias or trenches layout of the interconnections per se H01L23/528; CAD of ICs G06F30/00
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 2224/02126 Collar structures
• CPC Class Codes: H01L 2224/02166 Collar structures
• CPC Class Codes: H01L 2224/023 Redistribution layers [RDL] for bonding areas
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/05006 Dual damascene structure
• CPC Class Codes: H01L 2224/05073 Single internal layer
• CPC Class Codes: H01L 2224/05147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05166 Titanium [Ti] as principal constituent
• CPC Class Codes: H01L 2224/05181 Tantalum [Ta] as principal constituent
• CPC Class Codes: H01L 2224/05187 Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2224/05546 Dual damascene structure
• CPC Class Codes: H01L 2224/05552 in top view
• CPC Class Codes: H01L 2224/05567 the external layer being at least partially embedded in the surface
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 2224/48624 : Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48724 : Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 23/5283 : Cross-sectional geometry
• CPC Class Codes: H01L 23/53238 : Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 24/03 : Manufacturing methods
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• CPC Class Codes: H01L 24/06 : of a plurality of bonding areas
• CPC Class Codes: H01L 24/45 : of an individual wire connector
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• 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 2924/0001 : Technical content checked by a classifier
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01031 : Gallium [Ga]
• CPC Class Codes: H01L 2924/01032 : Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01073 : Tantalum [Ta]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/04941 : TiN
• CPC Class Codes: H01L 2924/04953 : TaN
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/30105 : Capacitance

Abstract

An interconnect comprises a trench and a number of metal layers above the trench. The trench has a depth and a width. The depth is greater than a critical depth, and the number of metal layers is a function of the width. In an alternate embodiment, a metallization structure having a trench including a metal layer and a second trench including a plurality of metal layers coupled to the metal layer is disclosed. The metal layer is highly conductive, and at least one of the plurality of metal layers is a metal layer that is capable of being reliably wire-bonded to a gold wire. The trench is narrower than the second trench, and at least one of the plurality of metal layers is copper or a copper alloy.

Claims

1. A computer system comprising:

a processor;

a device coupled to the processor; and

an interconnect coupled to the device, the interconnect comprising;

a trench having a depth greater than a critical depth and a metal layer; and

a bond pad trench having a bond pad depth equal to the depth and a plurality of metal layers coupled to the metal layer.

2. The computer system of claim 1, wherein the interconnect includes a conductive wire eutectically bonded to at least one of the plurality of metal layers.

3. A computer system comprising:

a processor;

a device coupled to the processor; and

a connective structure coupled to the device, the connective structure comprising;

a trench having a depth greater than a critical depth, a first barrier layer, and a copper layer above the first barrier layer;

a bond pad trench including a second barrier layer, the bond pad trench having the copper layer above the second barrier layer, and the bond pad trench having a titanium layer above the copper layer, and an aluminum-copper layer above the titanium layer.

4. A computer system comprising:

a processor;

a device coupled to the processor; and

an interconnect coupled to the device, the interconnect comprising;

a fine line having a conductive layer; and

a wide line having a number of conductive layers, and at least one of the number of conductive layers of the wide line being coupled to the fine line.

5. The computer system of claim 4, wherein the wide line is capable of being reliably wire bonded to a conductive gold wire.

6. A computer system comprising:

a processor;

a device coupled to the processor; and

an interconnect coupled to the device, the interconnect comprising;

a fine line having a depth greater than a critical depth, a barrier layer and a layer of electroplated copper; and

a wide line having a wide line depth equal to the depth, a number of conductive layers, and at least one of the number of conductive layers coupled to the electroplated copper.

7. The computer system of claim 6, wherein at least one of the number of conductive layers is wire-bonded to a gold wire.

8. The computer system of claim 6, wherein a eutectic bond is used to wire-bond at least one of the number of conductive layers to a gold wire.

9. A computer system comprising:

a processor;

a device coupled to the processor; and

a conductive structure coupled to the device, the conductive structure comprising;

a fine line having a layer of electroplated copper; and

a wide line having a number of conductive layers, at least one of the number of conductive layers is capable of eutectic bonding to a gold wire, and the wide line is coupled to the fine line.

10. A computer system comprising:

a processor;

a device coupled to the processor; and

a connective structure coupled to the device, the connective structure comprising;

a fine line having a single layer of electroplated copper having a depth greater than a critical depth; and

a wide line having a stack of conductive layers capable of eutectic bonding to a gold wire, and the wide line coupled to the fine line and the wide line having a depth greater than a critical depth.

11. A computer system comprising:

a processor;

a device coupled to the processor; and

a conductive structure coupled to the device, the conductive structure comprising;

a fine line having a depth greater than a critical depth and a single layer of electroplated copper; and

a wide line having a wide line depth equal to the depth, and a stack comprising a barrier layer, a copper layer, and an aluminum layer capable of eutectic bonding to a conductive material, and the wide line coupled to the fine line.

12. The computer system of claim 11, wherein the barrier layer comprises a refractory metal.

13. The computer system of claim 12, wherein the refractory metal includes a refractory metal nitride.

14. A computer system comprising:

a processor;

a device coupled to the processor; and

a conductive structure coupled to the device, the conductive structure comprising;

a trench including a first barrier layer and a seed layer, the trench having a depth and a width, the depth being greater than a critical depth; and

one or more metal layers above the seed layer;

wherein a number of one or more metal layers included in the trench is determined by the width, and wherein the critical depth includes a vertical thickness of the first barrier layer and a vertical thickness of the seed layer and a vertical thickness of a metal layer and a vertical thickness of a second barrier layer.

15. The computer system of claim 14, wherein at least one of the one or more metal layers is fabricated from copper.

16. The computer system of claim 14, wherein at least one of one or more metal layers is fabricated from aluminum.

17. The computer system of claim 16, wherein the at least one of the one or more metal layer fabricated from aluminum is wire-bonded to a gold conductor.

18. A computer system comprising:

a processor;

a device coupled to the processor; and

a conductive structure coupled to the device, the conductive structure comprising;

a trench including a first barrier layer and a seed layer, the trench having a depth and a width, the depth being greater than a critical depth; and

one or more metal layers above the seed layer;

a wire-bond coupled to one of the one or more metal layers;

wherein a number of the one or more metal layers included in the trench is determined by the width, and wherein the critical depth includes a vertical thickness of the first barrier layer and a vertical thickness of the seed layer and a vertical thickness of a metal layer and a vertical thickness of a second barrier layer.

19. The computer system of claim 18, wherein the wire-bond includes a gold conductor.

20. The computer system of claim 18, wherein the wire-bond is coupled to the one or more metal layers through an opening in a passivation layer.

21. The computer system of claim 18, wherein one or the one metal layers includes an aluminum copper alloy.

22. A computer system comprising:

a processor;

a device coupled to the processor; and

a conductive structure coupled to the device, the conductive structure comprising;

a trench including a first barrier layer and a seed layer, the trench having a depth and a width; and

a number of metal layers above the trench, wherein for the depth being greater than a critical depth, the number of metal layers are capable of being increased as the width increases, and wherein the critical depth includes a vertical thickness of the first barrier layer and a vertical thickness of the seed layer and a vertical thickness of a metal layer and a vertical thickness of a second barrier layer.

23. The computer system of claim 22, wherein a first metal layer of the number of metal layers includes copper.

24. The computer system of claim 22, wherein a second metal layer of the number of metal layers includes aluminum.

25. The computer system of claim 22, wherein at least one of the number of metal layers is wire bonded to a conductor including gold.

26. A computer system comprising:

a processor;

a device coupled to the processor; and

a conductive structure coupled to the device, the conductive structure comprising;

a first trench including a first barrier layer, a seed layer, and a first metal layer above the seed layer, the first trench having a depth greater than a critical depth and a width less than a critical width;

a second trench including the first barrier layer, the seed layer, and the first metal layer above the seed layer, the second trench having the depth of the first trench and a width greater than the critical width;

a second metal layer above the second trench;

wherein the critical depth includes a vertical thickness of the first barrier layer and a vertical thickness of the seed layer and a vertical thickness of the first metal layer and a vertical thickness of a second barrier layer.

27. The computer system of claim 26, wherein the critical width includes a sum calculated as twice the sum of a side wall thickness for the first barrier layer, a sidewall thickness for the seed layer, and a sidewall thickness for the first metal layer.

28. The computer system of claim 26, wherein the first metal layer includes copper.

29. The computer system of claim 26, wherein the second metal layer includes aluminum.

30. The computer system of claim 26, wherein the second metal layer includes an aluminum copper alloy.

31. The interconnect of claim 26, wherein the second metal layer is wire-bonded to a gold conductor.

32. A computer system comprising:

a processor;

a device coupled to the processor; and

a conductive structure coupled to the device, the conductive structure comprising;

an first insulating layer including a conductive layer;

a second insulating layer above the first insulating layer, the second insulating layer having a final thickness; and

a first trench and a second trench fabricated on the second insulating layer, the first trench and the second trench each including a first barrier layer, a seed layer, and a first metal layer of a plurality of metal layers, the first trench and the second trench each having a depth greater than a critical depth but less than the final thickness, the first trench having a width less than a critical width, the second trench having a width greater than the critical width,

wherein the critical depth includes a vertical thickness of the first barrier layer and a vertical thickness of the seed layer and a vertical thickness of the first metal layer of a plurality of metal layers and a vertical thickness of a second barrier layer.

33. The computer system of claim 32, wherein the device includes a memory device.

34. The computer system of claim 32, wherein the depth and the width of the first trench are selected to provide a particular resistance when the first metal layer is copper.

35. The computer system of claim 32, wherein the first trench includes an opening coupling the first trench and the conductive layer.

36. The computer system of claim 32, further including a substrate, the first insulating layer above the substrate.

37. The computer system of claim 32, wherein the second trench includes the second barrier layer.

38. The computer system of claim 37, wherein the second trench includes a second metal layer of the plurality of metal layers, the second metal layer of the plurality of metal layers formed above the second barrier layer.

39. A computer system comprising:

a processor;

a device coupled to the processor; and

a conductive structure coupled to the device, the conductive structure comprising;

a plurality of trenches fabricated on an insulating layer, the plurality of trenches having a depth greater than a critical depth, wherein the critical depth includes a vertical thickness of a first barrier layer and a vertical thickness of a seed layer and a vertical thickness of a first metal layer of a plurality of metal layers and a vertical thickness of a second barrier layer; and

at least one of the plurality of trenches includes a width greater than a critical width, the critical width including a sum including twice the sum of a side wall thickness for the first barrier layer, a sidewall thickness for the seed layer, and a sidewall thickness for the first metal layer.

40. The computer system of claim 39, wherein at least one of the plurality of trenches having a width greater than the critical width includes the second barrier layer and a second metal layer.

41. The computer system of claim 40, wherein the second metal layer is coupled to a gold wire.

42. The computer system of claim 39, wherein at least one of the plurality of trenches includes a width less than the critical width.

43. The computer system of claim 42, wherein the at least one of the plurality of trenches including a width less than the critical width is located above an insulative layer having a conductive layer, the at least one of the plurality of trenches coupled through an opening to the conductive layer.