Abstract: A method to fabricate an imprint template for bit-patterned magnetic recording media using block copolymers (BCPs) integrates data region patterning and servo region patterning. A heat sink layer is formed on the imprint substrate only in the data regions. A sublayer for the BCP is deposited over both the data regions and the servo regions and patterned to form stripes in the data regions and servo features in the servo regions. A BCP is then deposited in both the data and servo regions. Only the BCP in the data regions is heated, which causes phase separation of the BCP in the data regions into the two BCP components. The selective heating may be accomplished by directed controlled laser radiation to only the data regions. The heat sink layer below the data regions absorbs the heat from the laser radiation, confining it to the data regions.

Abstract: A method to fabricate an imprint template for bit-patterned magnetic recording media using block copolymers (BCPs) integrates data region patterning and servo region patterning. A heat sink layer is formed on the imprint substrate only in the data regions. A sublayer for the BCP is deposited over both the data regions and the servo regions and patterned to form stripes in the data regions and servo features in the servo regions. A BCP is then deposited in both the data and servo regions. Only the BCP in the data regions is heated, which causes phase separation of the BCP in the data regions into the two BCP components. The selective heating may be accomplished by directed controlled laser radiation to only the data regions. The heat sink layer below the data regions absorbs the heat from the laser radiation, confining it to the data regions.

Abstract: The present disclosure relates to a protective layer composition that includes TixSiyA, where A is Cm, CmNl, OnCm, or OnCmNl and x, y, l, m, and n are positive integers. In one implementation, the protective layer composition has a ratio of x over (x+y) in the range of between about 0.1 and about 1.0. In another implementation, the protective layer composition has a ratio of x over (x+y) in the range of between about 0.3 and about 0.9. In yet another implementation, the protective layer composition has a ratio of x over (x+y) that is about 0.6. The protective layer composition may be amorphous. Also, the protective layer composition may include an atomic percentage of Ti that is less than about 20%. In one implementation of the protective layer composition, x is 2, y is 1, and A is C3.

Abstract: A vacuum planarization method substantially improves the surface roughness of a thermally-assisted recording (TAR) disk that has a recording layer (RL) formed of a substantially chemically-ordered FePt alloy or FePt-X alloy (or CoPt alloy or CoPt-X alloy) and a segregant, like SiO2. A first amorphous carbon overcoat (OC1) is deposited on the RL and etched with a non-chemically reactive plasma to remove at least one-half the thickness of OC1. Then a second amorphous carbon overcoat (OC2) is deposited on the etched OC1. The OC2 is then reactive-ion-etched, for example in a H2/Ar plasma, to remove at least one-half the thickness of OC2. A thin third overcoat (OC3) may be deposited on the etched OC2.

Abstract: The present disclosure relates to a protective layer composition that includes TixSiyA, where A is Cm, CmNl, OnCm, or OnCmNl and x, y, l, m, and n are positive integers. In one implementation, the protective layer composition has a ratio of x over (x+y) in the range of between about 0.1 and about 1.0. In another implementation, the protective layer composition has a ratio of x over (x+y) in the range of between about 0.3 and about 0.9. In yet another implementation, the protective layer composition has a ratio of x over (x+y) that is about 0.6. The protective layer composition may be amorphous. Also, the protective layer composition may include an atomic percentage of Ti that is less than about 20%. In one implementation of the protective layer composition, x is 2, y is 1, and A is C3.

Abstract: A method of making a thermally-assisted recording (TAR) disk includes etching an initial layer of generally spherically shaped FePt grains encapsulated by shells of graphitic carbon layers. The etching partially or completely removes the carbon layers on the tops of the shells, exposing the FePt grains while leaving carbon segregant material between the FePt grains. Additional Fe, Pt and C are then simultaneously deposited. The additional Fe and Pt grow on the exposed FePt grains and increase the vertical height of the grains, resulting in growth of columnar FePt grains. The additional C forms on top of the grains that together with the intergranular carbon form larger carbon shells. The resulting FePt grains thus have a generally columnar shape with perpendicular magnetic anisotropy, rather than a generally spherical shape. Lateral grain isolation is maintained by the carbon segregant remaining between the grains.

Abstract: A method of making a thermally-assisted recording (TAR) disk includes etching an initial layer of generally spherically shaped FePt grains encapsulated by shells of graphitic carbon layers. The etching partially or completely removes the carbon layers on the tops of the shells, exposing the FePt grains while leaving carbon segregant material between the FePt grains. Additional Fe, Pt and C are then simultaneously deposited. The additional Fe and Pt grow on the exposed FePt grains and increase the vertical height of the grains, resulting in growth of columnar FePt grains. The additional C forms on top of the grains that together with the intergranular carbon form larger carbon shells. The resulting FePt grains thus have a generally columnar shape with perpendicular magnetic anisotropy, rather than a generally spherical shape. Lateral grain isolation is maintained by the carbon segregant remaining between the grains.

Abstract: A vacuum planarization method substantially improves the surface roughness of a thermally-assisted recording (TAR) disk that has a recording layer (RL) formed of a substantially chemically-ordered FePt alloy or FePt-X alloy (or CoPt alloy or CoPt-X alloy) and a segregant, like SiO2. A first amorphous carbon overcoat (OC1) is deposited on the RL and etched with a non-chemically reactive plasma to remove at least one-half the thickness of OC1. Then a second amorphous carbon overcoat (OC2) is deposited on the etched OC1. The OC2 is then reactive-ion-etched, for example in a H2/Ar plasma, to remove at least one-half the thickness of OC2. A thin third overcoat (OC3) may be deposited on the etched OC2.

Abstract: A magnetic recording disk with pre-patterned surface features of elevated lands and recessed grooves or trenches, like a discrete-track media (DTM) or bit-patterned media (BPM) disk, has a planarized surface. A multilayered disk overcoat is used to protect the recording layer, and at least one of the overcoat layers functions as a stop layer for terminating a chemical-mechanical polishing (CMP) process that substantially planarizes the disk. All of the layers of the multilayered overcoat are located above the lands, but none of the overcoat layers, or a number of layers less than the number of layers over the lands, is located above the recesses.

Abstract: A magnetic recording disk with pre-patterned surface features of elevated lands and recessed grooves or trenches, like a discrete-track media (DTM) or bit-patterned media (BPM) disk, has a planarized surface. A multilayered disk overcoat is used to protect the recording layer, and at least one of the overcoat layers functions as a stop layer for terminating a chemical-mechanical polishing (CMP) process that substantially planarizes the disk. All of the layers of the multilayered overcoat are located above the lands, but none of the overcoat layers, or a number of layers less than the number of layers over the lands, is located above the recesses.