Structures and methods to enhance copper metallization

• US 6,743,716 B2
• Filed: 07/16/2002
• Issued: 06/01/2004
• Est. Priority Date: 01/18/2000
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Farrar, Paul A.
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): Le, Thao P
• Application Number:
  US10/196,078
• Publication Number:
  US 20020182858A1
• Time in Patent Office: 686 Days
• Field of Search: 438/652, 438/623
• US Class Current: 438/652
• CPC Class Codes: H01L 21/32051 Deposition of metallic or metal-silicide layers
• CPC Class Codes: H01L 21/76814 post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
• CPC Class Codes: H01L 21/76823 transforming an insulating layer into a conductive layer
• CPC Class Codes: H01L 21/76825 by exposing the layer to particle radiation, e.g. ion implantation, irradiation with UV light or electrons etc. plasma treatment H01L21/76826
• CPC Class Codes: H01L 21/76828 thermal treatment
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: H01L 21/76841 Barrier, adhesion or liner layers
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76855 After-treatment introducing at least one additional element into the layer
• CPC Class Codes: H01L 21/76859 by ion implantation
• CPC Class Codes: H01L 21/76867 characterized by methods of formation other than PVD, CVD or deposition from a liquids PVD H01L21/2855; CVD H01L21/28556; deposition from liquids H01L21/288
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 21/76874 for electroless plating
• CPC Class Codes: H01L 21/76879 by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288
• CPC Class Codes: H01L 21/7688 by deposition over sacrificial masking layer, e.g. lift-off lift-off per se H01L21/0272
• CPC Class Codes: H01L 23/53228 the principal metal being copper
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/5329 Insulating materials
• CPC Class Codes: H01L 23/53295 Stacked insulating 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

Disclosed structures and methods inhibit atomic migration and related capacitive-resistive effects between a metallization layer and an insulator layer in a semiconductor structure. One exemplary structure includes an inhibiting layer between an insulator and a metallization layer. The insulator includes a polymer or an insulating oxide compound. And, the inhibiting layer has a compound formed from a reaction between the polymer or insulating oxide compound and a transition metal, a representative metal, or a metalloid.

Claims

1. A method for forming a semiconductor structure, the method comprising:

forming a protective layer that comprises an insulator nitride compound;

forming a first insulator layer abutting the protective layer;

forming at least one opening through the protective layer and the first insulator layer;

depositing a first and second contact materials to form at least one contact plug in the at least one opening, wherein the first contact material includes titanium nitride, and wherein the second contact material includes tungsten;

forming a second insulator layer, wherein forming the second insulator layer includes depositing a substance with a first thickness and curing the substance, and wherein the substance comprises polyimide;

forming a first metallization pattern in the second insulator layer;

implanting into the second insulator layer a dose of about 5×

10¹⁶ ions per square centimeters of zirconium at about 400 electron-volts to about 600 electron-volts with the angle of implantation varying from about 5 degrees to about 10 degrees from normal;

forming an inhibiting layer on the second insulator layer by reacting zirconium with polyimide at about 325 degrees Celsius to about 375 degrees Celsius for about 27 minutes to about 33 minutes;

forming a seed layer of copper on the inhibiting layer; and

electroplating the seed layer so as to form a copper metallization layer.

2. The method of claim 1, wherein forming the protective layer includes forming the protective layer with a nitride compound that comprises silicon nitride, wherein silicon nitride includes trisilicon tetranitride.

3. The method of claim 2, wherein forming the protective layer includes forming the protective layer with a thickness of about 100 nanometers.

4. The method of claim 1, wherein forming the protective layer includes forming the protective layer before forming the first insulator layer.

5. The method of claim 1, wherein forming the first insulator layer includes forming the first insulator layer before forming the protective layer.

6. The method of claim 1, wherein forming the first insulator layer includes forming the first insulator layer that comprises a material selected from a group consisting of a polymer and a foamed polymer, wherein the polymer comprises a polyimide.

7. The method of claim 6, wherein forming the first insulator layer further comprises curing the polyimide.

8. The method of claim 1, further comprising removing undesired portions of the first and second contact materials by chemical-mechanical polishing.

9. The method of claim 1, further comprising heat-treating the semiconductor structure at about 250 degrees Celsius to about 350 degrees Celsius from about one to about two hours after implanting and electroplating.

10. A method for forming a semiconductor structure, the method comprising:

forming a protective layer that comprises an insulator nitride compound;

forming a first insulator layer abutting the protective layer;

forming at least one opening through the protective layer and the first insulator layer;

depositing a first and second contact materials to form at least one contact plug in the at least one opening, wherein the first contact material includes titanium nitride, and wherein the second contact material includes tungsten;

forming a second insulator layer, wherein forming the second insulator layer includes depositing a substance with a first thickness, and wherein the substance comprises an insulator oxide compound;

forming a first metallization pattern in the second insulator layer;

implanting into the second insulator layer a dose of about 5×

10¹⁶ ions per square centimeters of aluminum at about 400 electron-volts to about 600 electron-volts with the angle of implantation varying from about 5 degrees to about 10 degrees from normal;

forming an inhibiting layer on the second insulator layer by reacting aluminum with the insulator oxide compound at about 325 degrees Celsius to about 375 degrees Celsius for about 30 minutes;

forming a seed layer of copper on the inhibiting layer; and

electroplating the seed layer so as to form a copper metallization layer.

11. The method of claim 10, wherein forming the protective layer includes forming the protective layer with a nitride compound that comprises silicon nitride, wherein silicon nitride includes trisilicon tetranitride.

12. The method of claim 11, wherein forming the protective layer includes forming the protective layer with a thickness of about 100 nanometers.

13. The method of claim 10, wherein forming the protective layer includes forming the protective layer before forming the first insulator layer.

14. The method of claim 10, wherein forming the first insulator layer includes forming the first insulator layer before forming the protective layer.

15. The method of claim 10, further comprising removing undesired portions of the first and second contact materials by chemical-mechanical polishing.

16. A method for forming a semiconductor structure, the method comprising:

forming a protective layer that comprises an insulator nitride compound;

forming a first insulator layer abutting the protective layer, wherein the first insulator layer comprises a polymer;

forming at least one opening through the protective layer and the first insulator layer;

depositing a first and second contact materials to form at least one contact plug in the at least one opening, wherein the first contact material includes titanium nitride, and wherein the second contact material includes tungsten;

forming a second insulator layer, wherein forming the second insulator layer includes depositing a substance with a first thickness, and wherein the substance comprises an insulator oxide compound;

forming a first metallization pattern in the second insulator layer;

implanting into the second insulator layer a dose of about 5×

10¹⁶ ions per square centimeters of aluminum at about 400 electron-volts to about 600 electron-volts with the angle of implantation varying from about 5 degrees to about 10 degrees from normal;

forming an inhibiting layer on the second insulator layer by reacting aluminum with the insulator oxide compound at about 325 degrees Celsius to about 375 degrees Celsius for about 30 minutes;

forming a seed layer of copper on the inhibiting layer; and

electroplating the seed layer so as to form a copper metallization layer.

17. The method of claim 16, wherein forming the protective layer includes forming the protective layer with a nitride compound that comprises silicon nitride, wherein silicon nitride includes trisilicon tetranitride.

18. The method of claim 17, wherein forming the protective layer includes forming the protective layer with a thickness of about 100 nanometers.

19. The method of claim 16, wherein forming the protective layer includes forming the protective layer before forming the first insulator layer.

20. The method of claim 16, wherein forming the first insulator layer includes forming the first insulator layer before forming the protective layer.

21. The method of claim 16, further comprising removing undesired portions of the first and second contact materials by chemical-mechanical polishing.

22. A method for forming a semiconductor structure, the method comprising:

forming a protective layer that comprises an insulator nitride compound;

forming a first insulator layer abutting the protective layer, wherein the first insulator layer comprises a foamed polymer;

forming at least one opening through the protective layer and the first insulator layer;

depositing a first and second contact materials to form at least one contact plug in the at least one opening, wherein the first contact material includes titanium nitride, and wherein the second contact material includes tungsten;

forming a second insulator layer, wherein forming the second insulator layer includes depositing a substance with a first thickness, and wherein the substance comprises an insulator oxide compound;

forming a first metallization pattern in the second insulator layer;

implanting into the second insulator layer a dose of about 5×

10¹⁶ ions per square centimeters of aluminum at about 400 electron-volts to about 600 electron-volts with the angle of implantation varying from about 5 degrees to about 10 degrees from normal;

forming an inhibiting layer on the second insulator layer by reacting aluminum with the insulator oxide compound at about 325 degrees Celsius to about 375 degrees Celsius for about 30 minutes;

forming a seed layer of copper on the inhibiting layer; and

electroplating the seed layer so as to form a copper metallization layer.

23. The method of claim 22, wherein forming the protective layer includes forming the protective layer with a nitride compound that comprises silicon nitride, wherein silicon nitride includes trisilicon tetranitride.

24. The method of claim 23, wherein forming the protective layer includes forming the protective layer with a thickness of about 100 nanometers.

25. The method of claim 22, wherein forming the protective layer includes forming the protective layer before forming the first insulator layer.

26. The method of claim 22, wherein forming the first insulator layer includes forming the first insulator layer before forming the protective layer.

27. The method of claim 22, further comprising removing undesired portions of the first and second contact materials by chemical-mechanical polishing.

28. A method for forming a semiconductor structure, the method comprising:

forming a protective layer that comprises an insulator nitride compound;

forming a first insulator layer abutting the protective layer, wherein the first insulator layer comprises a fluorinated-foamed polyimide;

forming at least one opening through the protective layer and the first insulator layer;

depositing a first and second contact materials to form at least one contact plug in the at least one opening, wherein the first contact material includes titanium nitride, and wherein the second contact material includes tungsten;

forming a second insulator layer, wherein forming the second insulator layer includes depositing a substance with a first thickness, and wherein the substance comprises an insulator oxide compound;

forming a first metallization pattern in the second insulator layer;

implanting into the second insulator layer a dose of about 5×

10¹⁶ ions per square centimeters of aluminum at about 400 electron-volts to about 600 electron-volts with the angle of implantation varying from about 5 degrees to about 10 degrees from normal;

forming an inhibiting layer on the second insulator layer by reacting aluminum with the insulator oxide compound at about 325 degrees Celsius to about 375 degrees Celsius for about 30 minutes;

forming a seed layer of copper on the inhibiting layer; and

electroplating the seed layer so as to form a copper metallization layer.

29. The method of claim 28, wherein forming the protective layer includes forming the protective layer with a nitride compound that comprises silicon nitride, wherein silicon nitride includes trisilicon tetranitride.

30. The method of claim 29, wherein forming the protective layer includes forming the protective layer with a thickness of about 100 nanometers.

31. The method of claim 28, wherein forming the protective layer includes forming the protective layer before forming the first insulator layer.

32. The method of claim 28, wherein forming the first insulator layer includes forming the first insulator layer before forming the protective layer.

33. The method of claim 28, further comprising removing undesired portions of the first and second contact materials by chemical-mechanical polishing.

34. The method of claim 28, wherein the fluorinated-foamed polyimide comprises a DuPont PI-2801 material.

35. A method for forming a semiconductor structure, the method comprising:

forming a protective layer comprising an insulator nitride compound;

forming a first insulator layer contacting the protective layer and comprising

a fluorinated-foamed polyimide;

forming at least one opening through the protective layer and the first insulator layer;

forming in the one opening a contact plug comprising titanium nitride and tungsten;

forming a second insulator layer of an oxide compound over the contact plug;

implanting aluminum into the second insulator layer;

forming an inhibiting layer on the second insulator layer by reacting aluminum with the oxide compound;

forming a copper layer on the inhibiting layer.

36. The method of claim 35, wherein the protective layer includes trisilicon tetranitride.

37. The method of claim 35, wherein the recited acts are performed in the recited order.

38. The method of claim 35, wherein the fluorinated-foamed polyimide comprises a DuPont PI-2801 material.

39. A method for forming a semiconductor structure, the method comprising:

forming a protective layer comprising an insulator nitride compound;

forming a first insulator layer contacting the protective layer and comprising

a fluorinated-foamed polyimide;

forming at least one opening through the protective layer and the first insulator layer;

forming in the one opening a contact plug comprising titanium nitride and tungsten;

forming a second insulator layer of an oxide compound over the contact plug;

implanting zirconium into the second insulator layer;

forming an inhibiting layer on the second insulator layer by reacting aluminum with the oxide compound;

forming a copper layer on the inhibiting layer.

40. The method of claim 39, wherein the protective layer includes trisilicon tetranitride.

41. The method of claim 39, wherein the recited acts are performed in the recited order.

42. The method of claim 39, wherein the fluorinated-foamed polyimide comprises a DuPont PI-2801 material.

43. A method for forming a semiconductor structure, the method comprising:

forming a protective layer comprising an insulator nitride compound;

forming a first insulator layer contacting the protective layer and comprising

a polymer;

forming at least one opening through the protective layer and the first insulator layer;

forming in the one opening a contact plug comprising titanium nitride and tungsten;

forming a second insulator layer of an oxide compound over the contact plug;

implanting zirconium into the second insulator layer;

forming an inhibiting layer on the second insulator layer by reacting aluminum with the oxide compound;

forming a copper layer on the inhibiting layer.

44. The method of claim 43, wherein the protective layer includes trisilicon tetranitride.

45. The method of claim 43, wherein the recited acts are performed in the recited order.

46. The method of claim 43, wherein the fluorinated-foamed polyimide comprises a DuPont PI-2801 material.