High-pressure anneal process for integrated circuits

• US 6,673,726 B1
• Filed: 03/24/1999
• Issued: 01/06/2004
• Est. Priority Date: 01/22/1996
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Wald, Phillip G., Lane, Richard H.
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): SARKAR, ASOK K
• Application Number:
  US09/275,841
• Time in Patent Office: 1,749 Days
• Field of Search: 438/660, 438/663, 438/795, 438/904
• US Class Current: 438/795
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/28176 with a treatment, e.g. annealing, after the formation of the definitive gate conductor
• CPC Class Codes: H01L 21/28185 with a treatment, e.g. annealing, after the formation of the gate insulator and before the formation of the definitive gate conductor
• CPC Class Codes: H01L 21/28194 by deposition, e.g. evaporation, ALD, CVD, sputtering, laser deposition H01L21/28202 takes precedence
• CPC Class Codes: H01L 21/28202 in a nitrogen-containing ambient, e.g. nitride deposition, growth, oxynitridation, NH3 nitridation, N2O oxidation, thermal nitridation, RTN, plasma nitridation, RPN
• CPC Class Codes: H01L 21/324 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/20 - H01L21/288 and H01L21/302 - H01L21/322 take precedence
• CPC Class Codes: H01L 29/513 the variation being perpendicular to the channel plane
• CPC Class Codes: H01L 29/518 the insulating material containing nitrogen, e.g. nitride, oxynitride, nitrogen-doped material
• CPC Class Codes: Y10S 438/904 Charge carrier lifetime control
• CPC Class Codes: Y10S 438/908 Utilizing cluster apparatus

Abstract

This invention embodies an improved process for annealing integrated circuits to repair fabrication-induced damage. An integrated circuit is annealed in a pressurized sealed chamber in which a forming gas comprising hydrogen is present. Pressurization of the chamber reduces the contribution made by the final anneal step to total thermal exposure by increasing the diffusion rate of the hydrogen into the materials from which the integrated circuit is fabricated. Ideally, the forming gas contains, in addition to hydrogen, at least one other gas such as nitrogen or argon that will not react with hydrogen and, thus, reduces the danger of explosion. However, the integrated circuit may be annealed in an ambiance containing only hydrogen gas that is maintained at a pressure greater than ambient atmospheric pressure.

Claims

1. A process for annealing an integrated circuit having a metal alloy conductor line forming a portion thereof, said process comprising:

placing the integrated circuit within a chamber;

introducing a gas including hydrogen into the chamber, said gas having a partial pressure of hydrogen within the gas at least greater than 25 percent of gas pressure;

pressurizing the chamber to a pressure greater than ambient atmospheric pressure using the gas; and

elevating a temperature of the integrated circuit to a temperature within a range of about 300°

C. to 500°

C.

2. The process of claim 1, wherein the gas includes at least one inert gas.

3. The process of claim 2, wherein the at least one inert gas is selected from the group consisting of nitrogen, helium, neon, and argon.

4. The process of claim 1, wherein the gas includes nitrogen.

5. The process of claim 1, wherein pressurizing the chamber comprises pressurizing the chamber to a pressure of about 10 atmospheres.

6. The process of claim 1, wherein elevating a temperature of the integrated circuit comprises elevating the temperature of the integrated circuit to about 400°

C.

7. A process for annealing an integrated circuit, said integrated circuit having metal alloy conductor lines having a melting point, said process comprising:

placing the integrated circuit within a chamber;

pressurizing the chamber with a gas including hydrogen to a pressure greater than ambient atmospheric pressure, said gas having a partial pressure of hydrogen within the gas greater than 25 percent of gas pressure; and

elevating a temperature of the integrated circuit to a temperature no greater than eighty percent of the melting point of the metal alloy conductor lines for a period to anneal at least a portion of one metal alloy conductor line of the metal alloy conductor lines.

8. The process of claim 7, wherein the gas includes at least one inert gas.

9. The process of claim 8, wherein the at least one inert gas is selected from the group consisting of nitrogen, helium, neon, and argon.

10. The process of claim 7, wherein the gas includes nitrogen.

11. The process of claim 7, wherein the chamber is pressurized to a pressure of about 10 atmospheres.

12. The process of claim 7, wherein the metal alloy conductor lines contain aluminum and the temperature of the integrated circuit is elevated to about 400°

C.

13. A process for annealing an integrated circuit, said integrated circuit having metal alloy conductor lines including aluminum, said process comprising:

placing the integrated circuit within a chamber;

introducing a gas including diatomic hydrogen into the chamber, said gas having a partial pressure of diatomic hydrogen within the gas greater than 25 percent of gas pressure;

pressurizing the chamber to greater than ambient atmospheric pressure; and

elevating a temperature of the integrated circuit to a temperature within a range of 350°

C. to 450°

C.

14. The process of claim 13, wherein the gas also comprises at least one inert gas.

15. The process of claim 14, wherein the at least one inert gas is selected from the group consisting of diatomic nitrogen, helium, neon, and argon.

16. The process of claim 13, wherein the gas also comprises nitrogen.

17. A process for annealing a wafer, said wafer containing a plurality of integrated circuits, said plurality of integrated circuits having metallized conductor lines having a melting point, said process comprising:

placing the wafer within a chamber;

pressurizing the chamber with a gas including hydrogen to a pressure greater than atmospheric pressure, said gas having a partial pressure of hydrogen within the gas greater than 25 percent of gas pressure; and

elevating a temperature of the wafer to a temperature of no more than eighty percent of the melting point of the metallized conductor lines.

18. The process of claim 17, wherein the gas includes at least one inert gas.

19. The process of claim 18, wherein the at least one inert gas is selected from the group consisting of nitrogen, helium, neon, and argon.

20. The process of claim 17, wherein the gas includes nitrogen.

21. The process of claim 17, wherein the gas includes diatomic nitrogen and diatomic hydrogen, with diatomic nitrogen being a predominant species present.

22. A process for annealing an integrated circuit having a metal alloy conductor line forming a portion thereof, said process comprising:

placing the integrated circuit within a chamber;

introducing a gas including hydrogen into the chamber, said gas having a partial pressure of hydrogen within the gas greater than 25 percent of gas pressure;

pressurizing the chamber to a pressure greater than ambient atmospheric pressure using the gas; and

raising a temperature of the integrated circuit to a temperature within a range of about 300°

C. to 500°

C.

23. The process of claim 22, wherein the gas includes at least one inert gas.

24. The process of claim 23, wherein the at least one inert gas is selected from the group consisting of nitrogen, helium, neon, and argon.

25. The process of claim 22, wherein the gas includes nitrogen.

26. The process of claim 22, wherein pressurizing the chamber comprises pressurizing the chamber to a pressure of about 10 atmospheres.

27. The process of claim 22, wherein raising a temperature of the integrated circuit comprises raising the temperature of the integrated circuit to about 400°

C.

28. The process of claim 22, wherein pressurizing the chamber comprises pressurizing the chamber to a pressure of about 25 atmospheres.

29. The process of claim 22, wherein pressurizing the chamber comprises pressurizing the chamber to a pressure in excess of 25 atmospheres.

30. A process for annealing an integrated circuit, said integrated circuit having metal alloy conductor lines having a melting point, said process comprising:

placing the integrated circuit within a chamber;

pressurizing the chamber with a gas including hydrogen to a pressure greater than ambient atmospheric pressure, said gas having a partial pressure of hydrogen within the gas greater than 25 percent of gas pressure; and

raising a temperature of the integrated circuit to a temperature no greater than eighty percent of the melting point of the metal alloy conductor lines for a period to anneal at least a portion of one metal alloy conductor line of the metal alloy conductor lines.

31. The process of claim 30, wherein the gas includes at least one inert gas.

32. The process of claim 31, wherein the at least one inert gas is selected from the group consisting of nitrogen, helium, neon, and argon.

33. The process of claim 30, wherein the gas includes nitrogen.

34. The process of claim 30, wherein the chamber is pressurized to a pressure of about 10 atmospheres.

35. The process of claim 30, wherein the metal alloy conductor lines contain aluminum and the temperature of the integrated circuit is raised to about 400°

C.

36. The process of claim 32, wherein pressurizing the chamber comprises pressurizing the chamber to a pressure of about 25 atmospheres.

37. The process of claim 32, wherein the pressurizing the chamber comprises pressurizing the chamber to a pressure in excess of 25 atmospheres.

38. A process for annealing an integrated circuit, said integrated circuit having metal alloy conductor lines including aluminum, said process comprising:

placing the integrated circuit within a chamber;

introducing a gas including diatomic hydrogen into the chamber, said gas having a partial pressure of diatomic hydrogen within the gas falls in a range at least greater than 25 percent of gas pressure;

pressurizing the chamber to a pressure greater than ambient atmospheric pressure; and

raising a temperature of the integrated circuit to a temperature within a range of 350°

C. to 450°

C.

39. The process of claim 38, wherein the gas also comprises at least one inert gas.

40. The process of claim 39, wherein said at least one inert gas is selected from the group consisting of diatomic nitrogen, helium, neon, and argon.

41. The process of claim 38, wherein the gas also comprises nitrogen.

42. A process for annealing a wafer, said wafer containing a plurality of integrated circuits, said plurality of integrated circuits having metallized conductor lines having a melting point, said process comprising:

placing the wafer within a chamber;

pressurizing the chamber with a gas including hydrogen to a pressure greater than atmospheric pressure, said gas having a partial pressure of hydrogen within the gas greater than 25 percent of gas pressure; and

raising a temperature of the wafer to a temperature of no more than eighty percent of the melting point of the metallized conductor lines.

43. The process of claim 42, wherein the gas includes at least one inert gas.

44. The process of claim 43, wherein the at least one inert gas is selected from the group consisting of nitrogen, helium, neon, and argon.

45. The process of claim 42, wherein the gas includes nitrogen.

46. The process of claim 42, wherein the gas includes diatomic nitrogen and diatomic hydrogen, with diatomic nitrogen being a predominant species present.

47. The process of claim 42, wherein pressurizing the chamber comprises pressurizing the chamber to a pressure of about 25 atmospheres.

48. The process of claim 42, wherein pressurizing the chamber comprises pressurizing the chamber to a pressure in excess of 25 atmospheres.

49. A process for annealing an integrated circuit having metal alloy circuit lines forming a portion thereof, said process comprising:

placing the integrated circuit within a chamber;

introducing a gas including hydrogen into the chamber, said gas having a partial pressure of hydrogen within the gas greater than 25 percent of gas pressure;

pressurizing the chamber to a pressure greater than ambient atmospheric pressure using the gas; and

increasing a temperature of the integrated circuit to a temperature within a range of about 300°

C. to 500°

C., said range no greater than eighty percent of a melting point of the metal alloy circuit lines.

50. The process of claim 49, wherein the gas includes at least one inert gas.

51. The process of claim 50, wherein the at least one inert gas is selected from the group consisting of nitrogen, helium, neon, and argon.

52. The process of claim 49, wherein the gas includes nitrogen.

53. The process of claim 49, wherein pressurizing the chamber comprises pressurizing the chamber to a pressure of about 10 atmospheres.

54. The process of claim 49, wherein increasing a temperature of the integrated circuit comprises increasing the temperature of the integrated circuit to about 400°

C.

55. A process for annealing an integrated circuit, said integrated circuit having metal alloy conductor lines having a melting point, said process comprising:

placing the integrated circuit within a chamber;

pressurizing the chamber with a gas including hydrogen to a pressure greater than ambient atmospheric pressure, said gas having a partial pressure of hydrogen within the gas greater than 25 percent of gas pressure; and

increasing a temperature of the integrated circuit to a temperature no greater than eighty percent of the melting point of the metal alloy conductor lines for a period to anneal at least a portion of one metal alloy conductor line of the metal alloy conductor lines.

56. The process of claim 55, wherein the gas includes at least one inert gas.

57. The process of claim 56, wherein the at least one inert gas is selected from the group consisting of nitrogen, helium, neon, and argon.

58. The process of claim 55, wherein the gas includes nitrogen.

59. The process of claim 55, wherein the chamber is pressurized to a pressure of about 10 atmospheres.

60. The process of claim 55, wherein the metal alloy conductor lines contain aluminum and the temperature of the integrated circuit is elevated to about 400°

C.

61. A process for annealing an integrated circuit, said integrated circuit having metal alloy conductor lines including aluminum, said process comprising:

placing the integrated circuit within a chamber;

introducing a gas including diatomic hydrogen into the chamber, said gas having a partial pressure of diatomic hydrogen greater than 25 percent of gas pressure;

pressurizing the chamber to a pressure greater than ambient atmospheric pressure; and

increasing a temperature of the integrated circuit to a temperature within a range of 350°

C. to 450°

C.

62. The process of claim 61, wherein the gas also comprises at least one inert gas.

63. The process of claim 62, wherein the at least one inert gas is selected from the group consisting of diatomic nitrogen, helium, neon, and argon.

64. The process of claim 61, wherein the gas also comprises nitrogen.

65. A process for annealing a wafer, said wafer containing a plurality of integrated circuits, said plurality of integrated circuits having metallized conductor lines having a melting point, said process comprising:

placing the wafer within a chamber;

pressurizing the chamber with a gas including hydrogen to a pressure greater than atmospheric pressure, said gas having a partial pressure of hydrogen within the gas greater than 25 percent of gas pressure; and

increasing a temperature of the wafer to a temperature of no more than eighty percent of the melting point of the metallized conductor lines.

66. The process of claim 65, wherein the gas includes at least one inert gas.

67. The process of claim 66, wherein the at least one inert gas is selected from the group consisting of nitrogen, helium, neon, and argon.

68. The process of claim 65, wherein the gas includes nitrogen.

69. The process of claim 65, wherein the gas includes diatomic nitrogen and diatomic hydrogen, with diatomic nitrogen being a predominant species present.