METHOD FOR PRODUCING SINGLE-SIDED SPUTTERED MAGNETIC RECORDING DISKS

• US 20070202312A1
• Filed: 02/23/2007
• Published: 08/30/2007
• Est. Priority Date: 05/09/2002
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Maxtor Corporation (Seagate Technology Holdings Plc)
• Inventors: Clasara, Ramon, Kim, Kwang
• Granted Patent: US 7,838,067 B2
• Time in Patent Office: Days
• US Class Current: 428/213
• CPC Class Codes: C23C 14/025 Metallic sublayers
• CPC Class Codes: G11B 5/7368 Non-polymeric layer under the lowermost magnetic recording layer base layers having a non-magnetic layer under a soft magnetic layer G11B5/736; magnetic recording media substrates G11B5/739
• CPC Class Codes: G11B 5/7369 Two or more non-magnetic underlayers, e.g. seed layers or barrier layers
• CPC Class Codes: G11B 5/7371 Non-magnetic single underlayer comprising nickel
• CPC Class Codes: G11B 5/8404 manufacturing base layers
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/256 Heavy metal or aluminum or compound thereof

Abstract

An information-storage media is provided that includes:

• • (a) a substrate disk 312 having first and second opposing surfaces;
  • (b) a first selected layer 304 on the first surface, the first selected layer having a first thickness;
  • (c) a second selected layer 308 on the second surface, the second selected layer having a second thickness, wherein the first and second selected layers have a different chemical composition than the substrate disk; and
  • (d) an information-storage layer 412 adjacent to one or both of the selected layers. The first and second thicknesses are different to provide an unequal stress distribution across the cross-section of the media.

Claims

1-17. -17. (canceled)

18. A method for producing an information-storage media, comprising:

providing an intermediate structure, the intermediate structure comprising a substrate disk having first and second sides and first and second interface layers, wherein the first interface layer is located adjacent to the first side, wherein the second interface layer is located adjacent to the second side, wherein the first and second interface layers have different chemical compositions than the substrate disk, and wherein the intermediate structure has a first flatness and

forming an information containing layer adjacent to one of the first and second interface layers to provide the information-storage media, wherein the information-storage media has a second flatness and wherein the first flatness is greater than the second flatness.

19. The method of claim 18, wherein the other one of the first and second interface layers is not adjacent to an information containing layer.

20. The method of claim 18, wherein the first interface layer has a lesser thickness than the second interface layer.

21. The method of claim 18, wherein the first and second interface layers have differing thicknesses and wherein the difference in thickness is at least about 0.075 microns.

22. The method of claim 18, wherein the first flatness is at least about 2 microns and the second flatness is no more than the first flatness.

24. The method of claim 18, wherein a first thickness of the first interface layer is no more than about 99.3% of a second thickness of the second interface layer.

25. The method of claim 18, wherein the difference in thickness between the first and second interface layers is at least about 0.075 microns.

26. The method of claim 18, wherein the information-storage layer is a ferromagnetic material, wherein the first and second interface layers comprise nickel phosphorus, wherein the first and second interface layers have the same chemical composition, wherein the information-storage layer is adjacent to the first interface layer and further comprising:

an underlayer positioned between the information-storage layer and the first interface layer; and

an overcoat layer, wherein the information-storage layer is positioned between the overcoat layer and the underlayer.

28. The method of claim 26, wherein the information-storage layer and underlayer are each in compression.

30. The method of claim 18, wherein a compressive stress in the first interface layer is less than a compressive stress in the second interface layer.

35. The method of claim 18, wherein the first and second interface layers are each in tension and wherein the information-storage layer is in compression.

37. The method of claim 18, wherein the providing step comprises:

depositing the first interface layer at a first thickness; and

depositing the second interface layer at a second thickness, wherein the first and second thicknesses are different.

38. The method of claim 18, wherein the providing step comprises:

depositing the first and second interface layers on the substrate disk, wherein, after the depositing step, the thicknesses of the first and second interface layers are at least substantially the same; and

removing unequal thicknesses from the first and second interface layers, wherein, after the removal step, the thickness of the first interface layer is less than the thickness of the second interface layer.

39. The method of claim 38, wherein the removing step comprises:

rough polishing only one of the first and second sides of the intermediate structure.

40. The method of claim 38, wherein the removing step comprises:

fine polishing only one of the first and second sides of the intermediate structure.

41. The method of claim 38, wherein the removing step comprises:

rough polishing only one of the first and second sides of the intermediate structure to remove a first thickness of the corresponding first and second interface layer; and

fine polishing the only one of the first and second sides to remove a second thickness of the corresponding first and second interface layer.

23. (canceled)

27. (canceled)

29. (canceled)

31-32. -32. (canceled)

36. (canceled)

42-53. -53. (canceled)

54. An information-storage media manufactured by a method, comprising:

providing an intermediate stricture, the intermediate stricture comprising a substrate disk having first and second sides and first and second interface layers, wherein the first interface layer is located adjacent to the first side, wherein the second interface layer is located adjacent to the second side, wherein the first and second interface layers have different chemical compositions than the substrate disk, and wherein the intermediate structure has a first flatness and

forming an information containing layer adjacent to one of the first and second interface layers to provide the information-storage media, wherein the information-storage media has a second flatness and wherein the first flatness is greater than the second flatness.

55. The media of claim 54, wherein the first and second interface layers comprise nickel phosphorus and wherein the other one of the first and second interface layers is not adjacent to an information containing layer.

56. The media of claim 54, wherein the first interface layer has a lesser thickness than the second interface layer and wherein the difference in thickness between the first and second interface layers is at least about 0.075 microns.

57. The media of claim 54, wherein the first and second interface layers have differing thicknesses and wherein the difference in thickness is at least about 0.075 microns.

58. The media of claim 54, wherein the first flatness is at least about 2 microns and the second flatness is no more than the first flatness and wherein a first thickness of the first interface layer is no more than about 99.3% of a second thickness of the second interface layer.

59. The media of claim 54, wherein the information-storage layer is a ferromagnetic material, wherein the information-storage layer is adjacent to the first interface layer, and further comprising:

an underlayer positioned between the information-storage layer and the first interface layer; and

an overcoat layer, wherein the information-storage layer is positioned between the overcoat layer and the underlayer, wherein the infonnation-storage layer and underlayer are each in compression.

60. The media of claim 54, wherein the first and second interface layers have the same chemical composition and wherein a compressive stress in the first interface layer is less than a compressive stress in the second interface layer.

61. The media of claim 54, wherein the information-storage layer is adjacent to the second interface layer and the second interface layer is located between the information-storage layer and the substrate disk, wherein the first side is free of an information-storage layer, and, wherein the information-storage layer is in tension.

62. The media of claim 54, wherein the first and second interface layers are each in tension and wherein the infonnation-storage layer is in compression.

63. The media of claim 54, wherein the providing step comprises:

depositing the first interface layer at a first thickness; and

depositing the second interface layer at a second thickness, wherein the first and second thicknesses are different.

64. The media of claim 54, wherein the providing step comprises:

depositing the first and second interface layers on the substrate disk, wherein, after the depositing step, the thicknesses of the first and second interface layers are at least substantially the same; and

removing unequal thicknesses from the first and second interface layers, wherein, after the removal step, the thickness of the first interface layer is less than the thickness of the second interface layer.

65. The media of claim 64, wherein the removing step comprises:

rough polishing only one of the first and second sides of the intermediate structure.

66. The media of claim 64, wherein the removing step comprises:

fine polishing only one of the first and second sides of the intermediate structure.

67. The media of claim 64, wherein the removing step comprises:

rough polishing only one of the first and second sides of the intermediate structure to remove a first thickness of the corresponding first and second interface layer; and

fine polishing the only one of the first and second sides to remove a second thickness of the corresponding first and second interface layer.

68. A method for producing an information-storage media, comprising:

depositing first and second interface layers on first and second sides, respectively, of a substrate disk, wherein the first and second interface layers have different chemical compositions than the substrate disk, and wherein the intermediate structure has a first flatness value;

removing unequal thicknesses from the first and second interface layers, wherein, after the removal step, the thickness of the first interface layer is less than the thickness of the second interface layer and a second flatness value is greater than the first flatness value; and

forming an information-storage layer adjacent to one of the first and second interface layers to provide the information-storage media, wherein the information-storage media has a third flatness value and wherein the second flatness is greater than the third flatness value.

69. The method of claim 68, wherein, after the depositing step, the thicknesses of the first and second interface layers are at least substantially the same, and wherein the other one of the first and second interface layers is not adjacent to an information-storage layer.

70. The method of claim 69, wherein, after the removing step, the first interface layer has a lesser thickness than the second interface layer and wherein the information-storage layer is adjacent to the first interface layer.

71. The method of claim 68, wherein the first and second interface layers have differing thicknesses and wherein the difference in thickness is at least about 0.075 microns.

72. The method of claim 68, wherein the second flatness value is at least about 2 microns and the first and third flatness values are no more than the first flatness value and wherein a first thickness of the first interface layer is no more than about 99.3% of a second thickness of the second interface layer.

73. The method of claim 68, wherein the information-storage layer is a ferromagnetic material, wherein the first and second interface layers comprise nickel phosphorus, wherein the first and second interface layers have the same chemical composition, wherein the information-storage layer is adjacent to the first interface layer, and further comprising:

an underlayer positioned between the information-storage layer and the first interface layer, wherein the first interface layer is thinner than the second interface layer; and

an overcoat layer, wherein the information-storage layer is positioned between the overcoat layer and the underlayer, wherein the information-storage layer and underlayer are each in compression.

74. The method of claim 68, wherein a compressive stress in the first interface layer is less than a compressive stress in the second interface layer.

75. The method of claim 68, wherein the information-storage layer is adjacent to the second interface layer and the second interface layer is located between the information-storage layer and the substrate disk, wherein the first side is free of an information-storage layer, and wherein the infonnation-storage layer is in tension.

76. The method of claim 68, wherein the first and second interface layers are each in tension and wherein the information-storage layer is in compression.

77. The method of claim 68, wherein the providing step comprises:

depositing the first interface layer at a first thickness; and

depositing the second interface layer at a second thickness, wherein the first and second thicknesses are different and wherein the removing step comprises;

rough polishing only one of the first and second sides of the intermediate structure.

78. The method of claim 68, wherein the providing step comprises:

depositing the first interface layer at a first thickness; and

depositing the second interface layer at a second thickness, wherein the first and second thicknesses are different and wherein the removing step comprises;

fine polishing only one of the first and second sides of the intermediate structure.

79. The method of claim 68, wherein the providing step comprises:

depositing the first interface layer at a first thickness; and

depositing the second interface layer at a second thickness, wherein the first and second thicknesses are different and wherein the removing step comprises;

rough polishing only one of the first and second sides of the intermediate structure to remove a first thickness of the corresponding first and second interface layer; and

fine polishing the only one of the first and second sides to remove a second thickness of the corresponding first and second interface layer.