DEPOSITION PROCESSES FOR TITANIUM NITRIDE BARRIER AND ALUMINUM

• US 20090087585A1
• Filed: 09/28/2007
• Published: 04/02/2009
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: LEE, WEI TI, Hassan, Mohd Fadzli Anwar, Guo, Ted, Kim, Ryeun Kwan, Ritchie, Alan A., Park, Hyung Chul, Wang, Yen-Chih
• Granted Patent: US 7,824,743 B2
• Time in Patent Office: Days
• US Class Current: 427/576
• CPC Class Codes: C23C 14/0036 Reactive sputtering
• CPC Class Codes: C23C 14/0089 in metallic mode
• CPC Class Codes: C23C 14/0641 Nitrides C23C14/0617 takes precedence
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01J 37/32706 Polarising the substrate
• CPC Class Codes: H01J 37/34 operating with cathodic sputtering H01J37/36 takes precedence ; methods of cathodic sputtering C23C14/34
• CPC Class Codes: H01L 21/2855 by physical means, e.g. sputtering, evaporation H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/28556 by chemical means, e.g. CVD, LPCVD, PECVD, laser CVD H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/32051 Deposition of metallic or metal-silicide layers
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76876 for deposition from the gas phase, e.g. CVD
• 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 23/53223 Additional layers associated with aluminium layers, e.g. adhesion, barrier, cladding 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

Embodiments described herein provide a method for forming two titanium nitride materials by different PVD processes, such that a metallic titanium nitride layer is initially formed by a PVD process in a metallic mode and a titanium nitride retarding layer is formed over a portion of the metallic titanium nitride layer by a PVD process in a poison mode. Subsequently, a first aluminum layer, such as an aluminum seed layer, may be selectively deposited on exposed portions of the metallic titanium nitride layer by a CVD process. Thereafter, a second aluminum layer, such as an aluminum bulk layer, may be deposited on exposed portions of the first aluminum layer and the titanium nitride retarding layer during an aluminum PVD process.

Claims

1. A method for forming a conductive material on a substrate, comprising:

positioning a substrate within a process chamber, wherein the substrate comprises a dielectric material disposed thereon, the dielectric material comprises an upper surface and apertures formed therein, and each aperture comprises a lower surface and sidewalls;

depositing a metallic titanium nitride layer on the upper surface of the dielectric material and on the lower surfaces and the sidewalls of the apertures during a first PVD process, wherein the first PVD process comprises generating a first plasma and flowing nitrogen gas at a flow rate of less than about 80 sccm during; and

depositing a titanium nitride retarding layer on the metallic titanium nitride layer during a second PVD process, wherein the second PVD process comprises generating a second plasma and flowing the nitrogen gas at a flow rate of about 80 sccm or greater, and depositing the titanium nitride retarding layer on the lower surfaces and sidewalls of the apertures at about 10% or less of the thickness as the titanium nitride retarding layer deposited across the field of the substrate.

2. The method of claim 1, wherein the first PVD process and the second PVD process are performed in the same process chamber.

3. The method of claim 1, wherein the first PVD process and the second PVD process are performed in separate process chambers.

4. The method of claim 2, wherein a RF bias is applied to the substrate during the first PVD process and the RF bias is removed from the substrate during the second PVD process.

5. The method of claim 4, wherein the RF bias is at a power level within a range from about 100 W to about 800 W during the first PVD process.

6. The method of claim 4, wherein a DC power is applied to a titanium target at a first power level within a range from about 20 kW to about 40 kW during the first PVD process and at a second power level within a range from about 5 kW to about 25 kW during the second PVD process.

7. The method of claim 1, wherein the flow rate of the nitrogen gas is about 55 sccm or less during the first PVD process.

8. The method of claim 1, wherein the metallic titanium nitride layer comprises metallic titanium nitride material having the chemical formula of Ti_xN_y, where x is within a range from about 1.5 to about 2 and y is about 1.

9. The method of claim 8, wherein the titanium nitride retarding layer comprises a titanium nitride retarding material having the chemical formula of Ti_xN_y, where x is about 1 and y is within a range from about 1 to about 1.2.

10. The method of claim 1, further comprising depositing a first aluminum layer selectively on exposed portions of the metallic titanium nitride layer while maintaining the titanium nitride retarding layer substantially free of the first aluminum layer during a CVD process.

11. The method of claim 10, further comprising depositing a second aluminum layer on the titanium nitride retarding layer and on the exposed portions of the first aluminum layer during another PVD process.

12. The method of claim 1, wherein the metallic titanium nitride layer has a thickness within a range from about 100 Å

to about 1,000 Å

.

13. The method of claim 12, wherein the thickness is within a range from about 200 Å

to about 500 Å

.

14. The method of claim 1, wherein the titanium nitride retarding layer has a thickness within a range from about 2 Å

to about 100 Å

.

15. The method of claim 14, wherein the thickness is within a range from about 10 Å

to about 50 Å

.

16. A method for forming a conductive material on a substrate, comprising:

positioning a substrate within a process chamber, wherein the substrate comprises a dielectric material disposed thereon, the dielectric material comprises an upper surface and apertures formed therein, and each aperture comprises a lower surface and sidewalls;

depositing a metallic titanium nitride layer on the upper surface of the dielectric material and on the lower surfaces and the sidewalls of the apertures during a first PVD process, wherein the metallic titanium nitride layer comprises a metallic titanium nitride material having the chemical formula of Ti_xN_y, where x is within a range from about 1.5 to about 2 and y is about 1; and

depositing a titanium nitride retarding layer on the metallic titanium nitride layer deposited on the upper surface of the dielectric material during a second PVD process, wherein the titanium nitride retarding layer comprises a titanium nitride retarding material having the chemical formula of Ti_xN_y, where x is about 1 and y is within a range from about 1 to about 1.2.

17. The method of claim 16, wherein the titanium nitride retarding layer deposited on the lower surfaces and sidewalls of the apertures is about 10% or less of the thickness as the titanium nitride retarding layer deposited across the field of the substrate.

18. The method of claim 16, wherein a RF bias is applied to the substrate during the first PVD process and the RF bias is removed from the substrate during the second PVD process.

19. The method of claim 18, wherein the RF bias is at a power level within a range from about 100 W to about 800 W during the first PVD process.

20. The method of claim 18, wherein a DC power is applied to a titanium target at a first power level within a range from about 20 kW to about 40 kW during the first PVD process and at a second power level within a range from about 5 kW to about 25 kW during the second PVD process.

21. The method of claim 16, wherein the first PVD process and the second PVD process are performed in the same process chamber.

22. The method of claim 16, wherein the first PVD process and the second PVD process are performed in separate process chambers.

23. A method for forming a conductive material on a substrate, comprising:

positioning a substrate within a PVD chamber, wherein the substrate comprises a dielectric material disposed thereon, the dielectric material comprises an upper surface and apertures formed therein, and each aperture comprises a lower surface and sidewalls;

depositing a metallic titanium nitride layer on the upper surface of the dielectric material and on the lower surfaces and the sidewalls of the apertures during a first PVD process within the PVD chamber, the first PVD process comprises;

flowing nitrogen gas into the PVD chamber at a flow rate of less than about 80 sccm;

applying a RF bias to the substrate; and

applying a first DC power to a titanium target at a power level within a range from about 20 kW to about 40 kW to ignite a first plasma; and

depositing a titanium nitride retarding layer on the metallic titanium nitride layer deposited on the upper surface of the dielectric material during a second PVD process within the PVD chamber, the second PVD process comprises;

flowing the nitrogen gas into the PVD chamber at a flow rate of about 80 sccm or greater;

removing the RF bias from the substrate; and

applying a second first DC power to the titanium target at a power level within a range from about 5 kW to about 25 kW to ignite a second plasma.

24. The method of claim 23, wherein the flow rate of the nitrogen gas is about 55 sccm or less during the first PVD process.

25. The method of claim 23, wherein the metallic titanium nitride layer comprises metallic titanium nitride material having the chemical formula of Ti_xN_y, where x is within a range from about 1.5 to about 2 and y is about 1.

26. The method of claim 25, wherein the titanium nitride retarding layer comprises titanium nitride retarding material having the chemical formula of Ti_xN_y, where x is about 1 and y is within a range from about 1 to about 1.2.

27. A method for forming a conductive material on a substrate, comprising:

positioning a substrate within a process chamber, wherein the substrate comprises a dielectric material disposed thereon, the dielectric material comprises an upper surface and apertures formed therein, and each aperture comprises a lower surface and sidewalls;

depositing a metallic titanium nitride layer on the upper surface of the dielectric material and on the lower surfaces and the sidewalls of the apertures during a first PVD process;

depositing a titanium nitride retarding layer on the metallic titanium nitride layer deposited over the upper surface of the dielectric material while maintaining the lower surface of the apertures substantially free of the titanium nitride retarding layer during a second PVD process;

depositing a first aluminum layer selectively on exposed portions of the metallic titanium nitride layer while maintaining the titanium nitride retarding layer free of the first aluminum layer during a CVD process; and

depositing a second aluminum layer on the titanium nitride retarding layer and on the exposed portions of the first aluminum layer during another PVD process.

28. The method of claim 27, wherein a first plasma is generated with nitrogen gas having a flow rate of less than about 80 sccm during the first PVD process, and a second plasma is generated with the nitrogen gas having a flow rate of greater than about 80 sccm during the second PVD process.

29. The method of claim 28, wherein the flow rate of the nitrogen gas is about 55 sccm or less during the first PVD process.

30. The method of claim 28, wherein a DC power is applied to a titanium target at a first power level within a range from about 20 kW to about 40 kW during the first PVD process and at a second power level within a range from about 5 kW to about 25 kW during the second PVD process.

31. The method of claim 27, wherein the first aluminum layer has a thickness within a range from about 300 Å

to about 600 Å

.

32. The method of claim 31, wherein the first aluminum layer and the second aluminum layer have a combined thickness within a range from about 1,000 Å

to about 10,000 Å

.

33. The method of claim 27 wherein the substrate is heated to a temperature within a range from about 50°

C. to about 250°

C. during the CVD process to deposit the first aluminum layer.

34. The method of claim 27, wherein the substrate is exposed to an aluminum precursor during the CVD process to deposit the first aluminum layer, the aluminum precursor is selected from the group consisting of alane compounds, aluminum borohydride compounds, alkyl aluminum compounds, alkyl aluminum hydride compounds, complexes thereof, derivates thereof, and combinations thereof.

35. The method of claim 34, wherein the aluminum precursor is selected from the group consisting of methylpyrrolidine:

alane, aluminum borohydride trimethylamine, dimethyl aluminum hydride, complexes thereof, derivates thereof, and combinations thereof.

36. A method for forming a conductive material on a substrate, comprising:

positioning a substrate within a PVD chamber, wherein the substrate comprises a dielectric material disposed thereon, the dielectric material comprises an upper surface and apertures formed therein, and each aperture comprises a lower surface and sidewalls;

depositing a metallic titanium nitride layer on the upper surface of the dielectric material and on the lower surfaces and the sidewalls of the apertures during a PVD process, wherein the metallic titanium nitride material has the chemical formula of Ti_xN_y, where x is within a range from about 1.5 to about 2 and y is about 1, and the PVD process comprises;

flowing nitrogen gas into the PVD chamber at a flow rate of less than about 80 sccm;

applying a RF bias to the substrate; and

applying a first DC power to a titanium target at a power level within a range from about 20 kW to about 40 kW to ignite a plasma;

transferring the substrate into a CVD chamber; and

depositing an aluminum layer on the metallic titanium nitride layer during a CVD process.

37. The method of claim 36, wherein the PVD process further comprises the flow rate of the nitrogen is about 55 sccm or less, and the power level is within a range from about 25 kW to about 35 kW.

38. The method of claim 36, further comprising depositing a titanium nitride retarding layer on the metallic titanium nitride layer deposited over the upper surface of the dielectric material while maintaining the lower surface of the apertures substantially free of the titanium nitride retarding layer during a second PVD process.

39. The method of claim 38, further comprising maintaining the titanium nitride retarding layer substantially free of the aluminum layer while selectively depositing the aluminum layer on exposed portions of the metallic titanium nitride layer during the CVD process.

40. The method of claim 38, wherein the second PVD process comprises:

flowing the nitrogen gas into the PVD chamber at a flow rate of about 80 sccm or greater;

removing the RF bias from the substrate; and

applying a second DC power to the titanium target at a power level within a range from about 5 kW to about 25 kW to ignite a second plasma.

41. The method of claim 36, wherein the aluminum layer has a thickness within a range from about 300 Å

to about 600 Å

.

42. The method of claim 36, wherein the substrate is heated to a temperature within a range from about 50°

C. to about 250°

C. during the CVD process while depositing the aluminum layer.

43. The method of claim 36, wherein the substrate is exposed to an aluminum precursor during the CVD process while depositing the aluminum layer, the aluminum precursor is selected from the group consisting of alane compounds, aluminum borohydride compounds, alkyl aluminum compounds, alkyl aluminum hydride compounds, complexes thereof, derivates thereof, and combinations thereof.

44. The method of claim 43, wherein the aluminum precursor is selected from the group consisting of methylpyrrolidine:

alane, aluminum borohydride trimethylamine, dimethyl aluminum hydride, complexes thereof, derivates thereof, and combinations thereof.

45. The method of claim 36, further comprising depositing another aluminum layer on the substrate during another PVD process.