Semiconductor device having a composite layer in addition to a barrier layer between copper wiring and aluminum bond pad

• US 20050067708A1
• Filed: 09/25/2003
• Published: 03/31/2005
• Est. Priority Date: 09/25/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: McKnight, Samuel R., Wong, Kwong H., Kelly, Adreanne A., Burrell, Lloyd G.
• Granted Patent: US 6,960,831 B2
• Time in Patent Office: Days
• US Class Current: 257/762
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/05073 Single internal layer
• CPC Class Codes: H01L 2224/05083 Three-layer arrangements
• 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 glass ceramics H01L2224/05188
• 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 2224/48624 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48724 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48824 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 23/53223 Additional layers associated with aluminium layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 24/05 of an individual bonding area
• CPC Class Codes: H01L 24/45 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 2924/00011 Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01024 : Chromium [Cr]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• 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 2924/01327 : Intermediate phases, i.e. intermetallics compounds
• CPC Class Codes: H01L 2924/04941 : TiN
• CPC Class Codes: H01L 2924/04953 : TaN
• CPC Class Codes: H01L 2924/0496 : 6th Group
• CPC Class Codes: H01L 2924/14 : Integrated circuits

Abstract

A semiconductor device, and a method of fabricating the device, having a copper wiring level and an aluminum bond pad above the copper wiring level. In addition to a barrier layer which is normally present to protect the copper wiring level, there is a composite layer between the aluminum bond pad and the barrier layer to make the aluminum bond pad more robust so as to withstand the forces of bonding and probing. The composite layer is a sandwich of a refractory metal and a refractory metal nitride.

Claims

1. A semiconductor device comprising:

a semiconductor base;

at least one copper wiring level on the semiconductor base;

a barrier layer having a first thickness on, and in direct contact with, the copper wiring level;

an aluminum bond pad on the barrier layer; and

a composite layer having a second thickness in addition to the barrier layer between the aluminum bond pad and the barrier layer wherein the composite layer comprises a refractory metal and a refractory metal nitride and wherein the second thickness is greater than the first thickness.

2. The semiconductor device of claim 1 wherein the composite layer comprises alternating layers of the refractory metal and the refractory metal nitride and there are at least two layers of each of the refractory metal and the refractory metal nitride.

3. The semiconductor device of claim 1 wherein the composite layer is directly on the barrier layer.

4. The semiconductor device of claim 1 wherein the composite layer is within the aluminum bond pad and spaced from the barrier layer.

5. The semiconductor device of claim 1 wherein the aluminum bond pad comprises first and second layers of aluminum and the composite layer is interposed between the first and second layers.

6. The semiconductor device of claim 5 wherein one of the first and second layers of the aluminum bond pad is in direct contact with the barrier layer.

9. The semiconductor device of claim 1 wherein the refractory metal of the composite layer is selected from the group consisting of tantalum, titanium and tungsten and the refractory metal nitride of the composite layer is selected from the group consisting of tantalum nitride, titanium nitride and tungsten nitride.

10. The semiconductor device of claim 1 wherein the thickness of the aluminum bond pad is 0.5 to 20 microns.

11. The semiconductor device of claim 1 wherein the refractory metal of the composite layer is tantalum and the refractory metal nitride is tantalum nitride.

12. The semiconductor device of claim 1 wherein the refractory metal of the composite layer is titanium and the refractory metal nitride is titanium nitride.

7. The semiconductor device of claim I wherein the barrier layer is selected from the group consisting of tantalum nitride, tantalum nitride/tantalum and tantalum nitride/titanium/titanium nitride.

8. The semiconductor device of claim 7 wherein the thickness of the barrier layer is 500 to 1000 angstroms.

13. The semiconductor device of claim I wherein the refractory metal of the composite layer is tungsten and the refractory metal nitride is tungsten nitride.

14. The semiconductor device of claim I wherein the composite layer is 1000 angstroms thick.

15. A method of manufacturing a semiconductor device comprising the steps of:

forming a semiconductor base;

forming at least one copper wiring level on the semiconductor base;

forming a barrier layer on, and in direct contact with, the copper wiring level;

forming a composite layer on the barrier layer wherein the composite layer comprises a refractory metal and a refractory metal nitride; and

forming an aluminum bond pad on the composite layer.

16. The method of claim 15 wherein the composite layer comprises alternating layers of the refractory metal and the refractory metal nitride and there are at least two layers of each of the refractory metal and the refractory metal nitride.

17. The method of claim 15 wherein the composite layer is directly on the barrier layer.

18. The method of claim 15 wherein the composite layer is within the aluminum bond pad.

19. The method of claim 15 wherein the aluminum bond pad comprises first and second layers and the composite layer is interposed between the first and second layers.

20. The method of claim 19 wherein one of the first and second layers of the aluminum bond pad is in direct contact with the barrier layer.