Polishing pad with foundation layer and polishing surface layer

1. A polishing pad for polishing a substrate, the polishing pad comprising:

a foundation layer having a first hardness; and

a polishing surface layer bonded directly to the foundation layer, the polishing surface layer having a second hardness less than the first hardness, wherein the polishing surface layer is covalently bonded to the foundation layer.

2. The polishing pad of claim 1 , wherein the polishing surface layer comprises a continuous layer portion with a plurality of polishing features protruding there from, the continuous layer portion bonded directly to the foundation layer.

3. The polishing pad of claim 1 , wherein the polishing surface layer. comprises a plurality of discrete polishing protrusions bonded directly to the foundation layer.

4. The polishing pad of claim 1 , wherein the foundation layer and the polishing surface layer have a peel resistance sufficient to withstand a shear force applied during the useful lifetime of the polishing pad.

5. The polishing pad of claim 1 , wherein the foundation layer has a surface roughness greater than approximately 1 micrometer Ra (root mean square) where the polishing surface layer is bonded directly to the foundation layer.

6. The polishing pad of claim 5 , wherein the surface roughness is approximately in the range of 5-10 micrometers Ra (root mean square).

7. The polishing pad of claim 1 , wherein the foundation layer has a smooth surface with a surface roughness less than approximately 1 micrometer Ra (root mean square) where the polishing surface layer is bonded directly to the foundation layer.

8. The polishing pad of claim 7 , wherein the polishing surface layer. comprises a material formed from polyurethane.

9. The polishing pad of claim 1 , wherein the foundation layer has an energy loss factor of less than approximately 100 KEL at 1/Pa at 40° C.

10. The polishing pad of claim 1 , wherein the foundation layer has a compressibility of less than approximately 1% under a central pressure of 5 PSI.

11. The polishing pad of claim 1 , wherein the foundation layer has a hardness greater than approximately 75 Shore D.

12. The polishing pad of claim 1 , wherein the foundation layer comprises a polycarbonate material.

13. The polishing pad of claim 1 , wherein the foundation layer comprises a material selected from the group consisting of an epoxy board material and a metal sheet.

14. The polishing pad of claim 1 , wherein the polishing surface layer has an energy loss factor of greater than approximately 1000 KEL at 1/Pa at 40° C.

15. The polishing pad of claim 1 , wherein the polishing surface layer has a compressibility of greater than approximately 0.1% under a central pressure of 5 PSI.

16. The polishing pad of claim 1 , wherein the polishing surface layer has a hardness less than approximately 70 Shore D.

17. The polishing pad of claim 1 , wherein the polishing surface layer is a homogeneous polishing surface layer.

18. The polishing pad of claim 17 , wherein the homogeneous polishing surface layer comprises a thermoset polyurethane material.

19. The polishing pad of claim 1 , wherein the polishing surface layer has a pore density of closed cell pores approximately in the range of 6% -50% total void volume.

20. The polishing pad of claim 1 , wherein the foundation layer has an energy loss factor of less than approximately 100 KEL at 1/Pa at 40° C., wherein the polishing surface layer has an energy loss factor of greater than approximately 1000 KEL at 1/Pa at 40° C., and wherein the foundation layer and the polishing surface layer together have an energy loss factor of less than approximately 100 KEL at 1/Pa at 40° C.

21. The polishing pad of claim 1 , wherein the foundation layer has a hardness approximately in the range of 70 - 90 Shore D, and the polishing surface layer has a hardness approximately in the range of 50 - 60 Shore D.

22. The polishing pad of claim 1 , wherein the foundation layer has a hardness approximately in the range of 70 - 90 Shore D, and the polishing surface layer has a hardness approximately in the range of 20 - 50 Shore D.

23. The polishing pad of claim 1 , wherein the polishing surface layer has a first modulus of elasticity, and the foundation layer has a second modulus of elasticity greater than approximately 10 times the first modulus of elasticity.

24. The polishing pad of claim 23 , wherein the polishing surface layer has a first modulus of elasticity, and the foundation layer has a second modulus of elasticity greater than approximately 100 times the first modulus of elasticity.

25. The polishing pad of claim 1 , wherein the polishing surface layer has a thickness approximately in the range of 2 - 50 mils, and the foundation layer has a thickness of greater than approximately 20 mils.

26. The polishing pad of claim 25 , wherein the thickness of the foundation layer is greater than the thickness of the polishing surface layer.

27. The polishing pad of claim 1 , wherein the foundation layer has a thickness and hardness relative to the thickness and hardness of the polishing surface layer sufficient to dictate the bulk polishing characteristics of the polishing pad.

28. The polishing pad of claim 1 , wherein the foundation layer is sufficiently thick for the polishing pad to provide die-level polishing planarity, but sufficiently thin for the polishing pad to provide wafer-level polishing uniformity.

29. The polishing pad of claim 1 , further comprising:

a detection region disposed in the foundation layer.

30. The polishing pad of claim 1 , further comprising:

an aperture disposed in the polishing pad, through the polishing surface layer and the foundation layer; and

an adhesive sheet disposed on a back surface of the foundation layer but not in the aperture, the adhesive sheet providing an impermeable seal for the aperture at the back surface of the foundation layer.

31. The polishing pad of claim 1 , further comprising:

a sub pad having a third hardness less than the first hardness, wherein the foundation layer is disposed proximate to the sub pad.

32. The polishing pad of claim 31 , wherein the foundation layer has a hardness approximately in the range of 70 - 90 Shore D, the polishing surface layer has a hardness approximately in the range of 20 60 Shore D, and the sub pad has a hardness less than approximately 90 Shore A.

33. The polishing pad of claim 31 , wherein the polishing pad provides die-level polishing planarity and wafer-level polishing uniformity.

34. The polishing pad of claim 1 , wherein the foundation layer comprises a stack of sub layers.

35. A polishing pad for polishing a substrate, the polishing pad comprising:

a foundation layer having a first hardness; and

a polishing surface layer bonded directly to the foundation layer, the polishing surface layer having a second hardness equal to or greater than the first hardness, wherein the polishing surface layer comprises a continuous layer portion with plurality of polishing features protruding there from, the continuous layer portion covalently bonded directly to the foundation layer.

36. The polishing pad of claim 35 , wherein the foundation layer and the polishing surface layer have a peel resistance sufficient to withstand a shear force applied during the useful lifetime of the polishing pad.

37. A polishing pad for polishing a substrate, the polishing pad comprising:

a foundation layer having a first hardness; and

a polishing surface layer bonded directly to the foundation layer, the polishing surface layer having a second hardness less than the first hardness, wherein the polishing surface layer comprises a plurality of discrete polishing protrusions bonded directly to the foundation layer.

38. The polishing pad of claim 37 , wherein the foundation layer and the polishing surface layer have a peel resistance sufficient to withstand a shear force applied during the useful lifetime of the polishing pad.

39. The polishing pad of claim 37 , wherein the foundation layer has a surface roughness greater than approximately 1 micrometer Ra (root mean square) where the polishing surface layer is bonded directly to the foundation layer.

40. The polishing pad of claim 39 , wherein the surface roughness is approximately in the range of 5 - 10 micrometers Ra (root mean square).

41. The polishing pad of claim 37 , wherein the foundation layer has a smooth surface with a surface roughness less than approximately 1 micrometer Ra (root mean square) where the polishing surface layer is bonded directly to the foundation layer.

42. The polishing pad of claim 41 , wherein the polishing surface layer comprises a material formed from polyurethane.

43. The polishing pad of claim 37 , wherein the foundation layer has an energy loss factor of less than approximately 100 KEL at 1/Pa at 40° C.

44. The polishing pad of claim 37 , wherein the foundation layer has a compressibility of less than approximately 1% under a central pressure of 5 PSI.

45. The polishing pad of claim 37 , wherein the foundation layer has a hardness greater than approximately 75 Shore D.

46. The polishing pad of claim 37 , wherein the foundation layer comprises a polycarbonate material.

47. The polishing pad of claim 37 , wherein the foundation layer comprises a material selected from the group consisting of an epoxy board material and a metal sheet.

48. The polishing pad of claim 37 , wherein the polishing surface layer has an energy loss factor of greater than approximately 1000 KEL at 1/Pa at 40° C.

49. The polishing pad of claim 37 , wherein the polishing surface layer has a compressibility of greater than approximately 0.1% under a central pressure of 5 PSI.

50. The polishing pad of claim 37 , wherein the polishing surface layer has a hardness less than approximately 70 Shore D.

51. The polishing pad of claim 37 , wherein the polishing surface layer is a homogeneous polishing surface layer.

52. The polishing pad of claim 51 , wherein the homogeneous polishing surface layer comprises a thermoset polyurethane material.

53. The polishing pad of claim 37 , wherein the polishing surface layer has a pore density of closed cell pores approximately in the range of 6% - 50% total void volume.

54. The polishing pad of claim 37 , wherein the foundation layer has an energy loss factor of less than approximately 100 KEL at 1/Pa at 40° C., wherein the polishing surface layer has an energy loss factor of greater than approximately 1000 KEL at 1/Pa at 40° C., and wherein the foundation layer and the polishing surface layer together have an energy loss factor of less than approximately 100 KEL at 1/Pa at 40° C.

55. The polishing pad of claim 37 , wherein the foundation layer has a hardness approximately in the range of 70 - 90 Shore D, and the polishing surface layer has a hardness approximately in the range of 50 - 60 Shore D.

56. The polishing pad of claim 37 , wherein the foundation layer has a hardness approximately in the range of 70 - 90 Shore D, and the polishing surface layer has a hardness approximately in the range of 20 - 50 Shore D.

57. The polishing pad of claim 37 , wherein the polishing surface layer has a first modulus of elasticity, and the foundation layer has a second modulus of elasticity greater than approximately 10 times the first modulus of elasticity.

58. The polishing pad of claim 57 , wherein the polishing surface layer has a first modulus of elasticity, and the foundation layer has a second modulus of elasticity greater than approximately 100 times the first modulus of elasticity.

59. The polishing pad of claim 37 , wherein the polishing surface layer has a thickness approximately in the range of 2 - 50 mils, and the foundation layer has a thickness of greater than approximately 20 mils.

60. The polishing pad of claim 59 , wherein the thickness of the foundation layer is greater than the thickness of the polishing surface layer.

61. The polishing pad of claim 37 , wherein the foundation layer has a thickness and hardness relative to the thickness and hardness of the polishing surface layer sufficient to dictate the bulk polishing characteristics of the polishing pad.

62. The polishing pad of claim 37 , wherein the foundation layer is sufficiently thick for the polishing pad to provide die-level polishing planarity, but sufficiently thin for the polishing pad to provide wafer-level polishing uniformity.

63. A polishing pad for polishing a substrate, the polishing pad comprising:

a foundation layer having a first hardness; and

a polishing surface layer bonded directly to the foundation layer, the polishing surface layer having a second hardness less than the first hardness, wherein the foundation layer has a surface roughness greater than approximately 1 micrometer Ra (root mean square) where the polishing surface layer is bonded directly to the foundation layer.

64. The polishing pad of claim 63 , wherein the polishing surface layer comprises a continuous layer portion with a plurality of polishing features protruding there from, the continuous layer portion bonded directly to the foundation layer.

65. The polishing pad of claim 63 , wherein the foundation layer and the polishing surface layer have a peel resistance sufficient to withstand a shear force applied during the useful lifetime of the polishing pad.

66. The polishing pad of claim 63 , wherein the surface roughness is approximately in the range of 5 - 10 micrometers Ra (root mean square).

67. The polishing pad of claim 63 , wherein the foundation layer has an energy loss factor of less than approximately 100 KEL at 1/Pa at 40° C.

68. The polishing pad of claim 63 , wherein the foundation layer has a compressibility of less than approximately 1% under a central pressure of 5 PSI.

69. The polishing pad of claim 63 , wherein the foundation layer comprises a polycarbonate material.

70. A polishing pad for polishing a substrate, the polishing pad comprising:

a foundation layer having a first hardness; and

a polishing surface layer bonded directly to the foundation layer, the polishing surface layer having a second hardness less than the first hardness, wherein the foundation layer has a smooth surface with a surface roughness less than approximately 1 micrometer Ra (root mean square) where the polishing surface layer is bonded directly to the foundation layer.

71. The polishing pad of claim 70 , wherein the polishing surface layer comprises a continuous layer portion with a plurality of polishing features protruding there from, the continuous layer portion bonded directly to the foundation layer.

72. The polishing pad of claim 70 , wherein the foundation layer and the polishing surface layer have a peel resistance sufficient to withstand a shear force applied during the useful lifetime of the polishing pad.

73. The polishing pad of claim 70 , wherein the foundation layer has an energy loss factor of less than approximately 100 KEL at 1/Pa at 40° C.

74. The polishing pad of claim 70 , wherein the foundation layer has a compressibility of less than approximately 1% under a central pressure of 5 PSI.

75. The polishing pad of claim 70 , wherein the foundation layer comprises a polycarbonate material.

76. A polishing pad for polishing a substrate, the polishing pad comprising:

a foundation layer having a first hardness; and

a polishing surface layer bonded directly to the foundation layer, the polishing surface layer having a second hardness less than the first hardness, wherein the foundation layer has an energy loss factor of less than approximately 100 KEL at 1/Pa at 40° C., wherein the polishing surface layer has an energy loss factor of greater than approximately 1000 KEL at 1/Pa at 40° C., and wherein the foundation layer and the polishing surface layer together have an energy loss factor of less than approximately 100 KEL at 1/Pa at 40° C.

77. The polishing pad of claim 76 , wherein the polishing surface layer comprises a continuous layer portion with a plurality of polishing features protruding there from, the continuous layer portion bonded directly to the foundation layer.

78. The polishing pad of claim 76 , wherein the foundation layer and the polishing surface layer have a peel resistance sufficient to withstand a shear force applied during the useful lifetime of the polishing pad.

79. The polishing pad of claim 76 , wherein the foundation layer has a surface roughness greater than approximately 1 micrometer Ra (root mean square) where the polishing surface layer is bonded directly to the foundation layer.

80. The polishing pad of claim 76 , wherein the foundation layer has a smooth surface with a surface roughness less than approximately 1 micrometer Ra (root mean square) where the polishing surface layer is bonded directly to the foundation layer.

81. The polishing pad of claim 76 , wherein the foundation layer has a compressibility of less than approximately 1% under a central pressure of 5 PSI.

82. The polishing pad of claim 76 , wherein the foundation layer comprises a polycarbonate material.