Integration of ALD tantalum nitride for copper metallization

• US 20050106865A1
• Filed: 06/10/2004
• Published: 05/19/2005
• Est. Priority Date: 09/26/2001
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Chang, Mei, Chung, Hua, Mosely, Roderick Craig, Maity, Nirmalya, Yu, Jick
• Granted Patent: US 7,049,226 B2
• Time in Patent Office: Days
• US Class Current: 438/685
• CPC Class Codes: C23C 16/34 Nitrides C23C16/303 takes precedence
• CPC Class Codes: C23C 16/4411 Cooling of the reaction chamber walls C23C16/45572 takes precedence
• CPC Class Codes: C23C 16/45504 Laminar flow
• CPC Class Codes: C23C 16/45508 Radial flow
• CPC Class Codes: C23C 16/45512 Premixing before introduction in the reaction chamber
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: C23C 16/45544 characterized by the apparatus
• CPC Class Codes: C23C 16/45563 Gas nozzles
• CPC Class Codes: C23C 16/45582 Expansion of gas before it reaches the substrate
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/76805 the opening being a via or contact hole penetrating the underlying conductor
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76844 Bottomless liners
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 21/76862 Bombardment with particles, e.g. treatment in noble gas plasmas; UV irradiation
• CPC Class Codes: H01L 21/76865 Selective removal of parts of the layer H01L21/76844 takes precedence
• CPC Class Codes: H01L 21/76871 Layers specifically deposited to enhance or enable the nucleation of further layers, i.e. seed layers

Abstract

A method and apparatus for depositing a tantalum nitride barrier layer is provided for use in an integrated processing tool. The tantalum nitride is deposited by atomic layer deposition. The tantalum nitride is removed from the bottom of features in dielectric layers to reveal the conductive material under the deposited tantalum nitride. Optionally, a tantalum layer may be deposited by physical vapor deposition after the tantalum nitride deposition. Optionally, the tantalum nitride deposition and the tantalum deposition may occur in the same processing chamber.

Claims

1. A method of forming a metal interconnect on a semiconductor substrate, comprising;

cleaning features formed in a dielectric layer and exposing a conductive material underlying the dielectric layer by generating a plasma in a remote plasma source, delivering radicals from the plasma to a first process chamber which contains the substrate, and contacting the features formed in the dielectric layer with the radicals prior to a barrier layer deposition;

depositing a tantalum nitride layer by atomic layer deposition within the features at a pressure between 1 and 10 Torr at a temperature between 200 and 300°

C. in a second process chamber;

depositing a tantalum layer by physical vapor deposition over the tantalum nitride layer in a third process chamber;

plasma etching the tantalum layer and the tantalum nitride in a fourth process chamber to remove at least a portion of the tantalum layer and the tantalum nitride layer at the bottom of the feature to reveal the conductive material;

optionally depositing additional tantalum or copper by physical vapor deposition on the tantalum layer; and

depositing a seed layer over the conductive material and the tantalum layer in a fifth processing chamber,

wherein the first processing chamber, the second processing chamber, the third processing chamber, the fourth processing chamber, and the fifth processing chamber are located in an integrated tool.

2. The method of claim 1, wherein the cleaning is performed at 40 to 200 mTorr for 30-120 seconds.

3. The method of claim 1, wherein the cleaning is performed with a plasma comprising RF power of 1 to 600 W, wafer bias is 10 to 100 W, and frequency is 1 to 4

4. The method of claim 1, wherein the cleaning is performed with a feed gas consisting of 0 to about 10 percent hydrogen and about 90 to 100 percent helium.

5. The method of claim 1, wherein the tantalum nitride deposition is performed at 100-300°

C. heater temperature and 1 to 5 Torr.

6. The method of claim 1, wherein the tantalum nitride deposition is performed for one minute or less time.

7. The method of claim 1, wherein the tantalum nitride deposition is performed with a tantalum containing precursor selected from the group comprising t-butylimino-tris(diethylamino)tantalum, pentakis (ethylmethylamino)tantalum, pentakis(dimethylamino)tantalum, pentakis (diethylamino)tantalum, t-butyliminotris(diethyl methylamino)tantalum, t-butylimino-tris(dimethylamino)tantalum, bis(cyclopentadienyl)tantalum trihydride, and bis(methylcyclopentadienyl)tantalum trihydride.

8. The method of claim 1, wherein the tantalum nitride deposition is performed with a nitrogen containing precursor selected from the group comprising ammonia, hydrazine, methylhydrazine, dimethylhydrazine, t-butylhydrazine, phenylhydrazine, azoisobutane, and ethylazide.

9. The method of claim 1, wherein the tantalum nitride deposition is performed with the tantalum containing precursor pulsed into the chamber at 100 to 3,000 sccm for 2.0 seconds or less.

10. The method of claim 1, wherein the tantalum nitride deposition is performed with the nitrogen containing precursor pulsed into the chamber at 100 to 3,000 sccm for 2.0 seconds or less.

11. The method of claim 1, wherein the tantalum nitride deposition is performed with argon flowing continuously into the chamber at 1,000 to 10,000 sccm.

12. The method of claim 1, wherein the tantalum layer deposition is performed at 10 to 50°

C. and wafer bias is 100 to 1000 W.

13. The method of claim 1, wherein the plasma etching is performed with the gas selected from the group comprising argon, nitrogen, or hydrogen.

14. The method of claim 1, wherein the plasma etching is performed with RF power of 100 to 1000 W for 1 to 20 seconds.

15. The method of claim 1, wherein the plasma etching is performed with a directional argon plasma.

16. The method of claim 1, further comprising depositing additional metal by physical vapor deposition on the tantalum layer.

17. The method of claim 16, further comprising depositing a bulk metal layer.

18. The method of claim 1, wherein the third and fourth process chambers are the same chamber.

19. The method of claim 1, wherein the fourth and fifth process chambers are the same chamber.

20. The method of claim 16, wherein the metal is selected from the group comprising copper, copper aluminum, copper tin, tantalum, tungsten, thallium, cobalt, titanium, and aluminum.

21. The method of claim 16, wherein the deposition is performed at 10 to 50°

C. and wafer bias of 100 to 1000 W.

22. The method of claim 1, wherein the seed layer is deposited by a method selected from the group comprising chemical vapor deposition, physical vapor deposition, electroplating, and electroless plating.

23. The method of claim 1, wherein the seed layer comprises a metal selected from the group comprising copper, copper aluminum, copper tin, tantalum, tungsten, thallium, cobalt, titanium, and aluminum.

24. The method of claim 1, further comprising a preliminary substrate surface cleaning with nitrogen before cleaning features formed in a dielectric layer and exposing a conductive material underlying the dielectric layer by generating a plasma in a remote plasma source, delivering radicals from the plasma to a first process chamber which contains the substrate, and contacting the features formed in the dielectric layer with the radicals prior to a barrier layer deposition.

25. The method of claim 1, wherein the plasma etching is performed with a noble gas.

26. A method of forming a metal interconnect on a semiconductor substrate, comprising;

cleaning features formed in a dielectric layer and exposing a conductive material underlying the dielectric layer by generating a plasma in a remote plasma source, delivering radicals from the plasma to a first process chamber which contains the substrate, and contacting the features formed in the dielectric layer with the radicals prior to a barrier layer deposition;

depositing a tantalum nitride layer by atomic layer deposition within the features at a pressure between 1 and 10 Torr at a temperature between 200 and 300°

C. in a second process chamber;

depositing a tantalum layer by physical vapor deposition over the tantalum nitride layer in a third process chamber;

plasma etching the tantalum layer and the tantalum nitride in the third process chamber to remove at least a portion of the tantalum layer and the tantalum nitride layer at the bottom of the feature to reveal the conductive material;

optionally depositing additional tantalum or copper by physical vapor deposition on the tantalum layer; and

depositing a seed layer over the conductive material and the tantalum layer in a fourth processing chamber,

wherein the first processing chamber, the second processing chamber, the third processing chamber, and the fourth processing chamber are located in an integrated tool.

27. The method of claim 26, wherein the cleaning is performed at 40 to 200 mTorr for 30-120 seconds.

28. The method of claim 26, wherein the cleaning is performed with a plasma comprising RF power of 1 to 600 W, wafer bias is 10 to 100 W, and frequency is 1 to 4 MHz.

29. The method of claim 26, wherein the cleaning is performed with a feed gas consisting of 0 to about 10 percent hydrogen and about 90 to 100 percent helium.

30. The method of claim 26, wherein the tantalum nitride deposition is performed at 100-300°

C. heater temperature and 1 to 5 Torr.

31. The method of claim 26, wherein the tantalum nitride deposition is performed for one minute or less time.

32. The method of claim 26, wherein the tantalum nitride deposition is performed with the tantalum containing precursor pulsed into the chamber at 100 to 3,000 sccm for 2.0 seconds or less.

33. The method of claim 26, wherein the tantalum nitride deposition is performed with the nitrogen containing precursor pulsed into the chamber at 100 to 3,000 sccm for 2.0 seconds or less.

34. The method of claim 26, wherein the tantalum nitride deposition is performed with argon flowing continuously into the chamber at 1,000 to 10,000 sccm.

35. The method of claim 26, wherein the tantalum layer deposition is performed at 10 to 50°

C. and wafer bias is 100 to 1000 W.

36. The method of claim 26, wherein the plasma etching is performed with RF power is 100 to 1000 W for 1 to 20 seconds.

37. The method of claim 26, wherein the plasma etching is performed with a directional argon plasma.

38. The method of claim 26, further comprising depositing additional metal by physical vapor deposition to the tantalum layer.

39. The method of claim 26, wherein the second and third process chambers are the same chamber.

40. The method of claim 26, wherein the third and fourth process chambers are the same chamber.

41. The method of claim 26, wherein the seed layer is deposited by a method selected from the group comprising chemical vapor deposition, physical vapor deposition, electroplating, and electroless plating.

42. The method of claim 26, further comprising depositing additional metal by physical vapor deposition to the tantalum layer.

43. The method of claim 42, further comprising depositing a bulk metal layer.

44. An apparatus for forming a metal interconnect on a semiconductor substrate, comprising;

a preclean chamber for cleaning features formed in a dielectric layer, the preclean chamber comprising a remote plasma source;

an atomic layer deposition chamber for depositing a tantalum nitride layer at a pressure between 1 and 10 Torr at a temperature between 200 and 300°

C.;

a physical vapor deposition chamber for depositing a tantalum layer;

a plasma etching chamber for plasma etching features in the tantalum layer and the tantalum nitride; and

a seed layer deposition chamber for depositing a seed layer in the features;

wherein the preclean chamber, the atomic layer deposition chamber, the physical vapor deposition chamber, the plasma etching chamber, and the seed layer deposition chamber are located in an integrated tool.

45. The apparatus of claim 44, further comprising a second physical vapor deposition chamber for depositing a bulk metal layer on the tantalum layer.