摘要:
A method for making a bit-patterned-media magnetic recording disk with discrete magnetic islands includes annealing the data islands after they have been formed by an etching process. A hard mask, such as a layer of silicon nitride or carbon, may be first formed on the recording layer and a patterned resist formed on the hard mask. The resist pattern is then transferred into the hard mask, which is used as the etch mask to etch the recording layer and form the discrete data islands. After the data islands are formed by the etching process, the patterned recording layer is annealed. The annealing may be done in a vacuum, or in an inert gas, like helium or argon, or in a forming gas such as a reducing atmosphere of argon plus hydrogen. The annealing improves the coercivity, the effective saturation magnetization and the thermal stability of the patterned media.
摘要:
A method for making a bit-patterned-media magnetic recording disk with discrete magnetic islands includes annealing the data islands after they have been formed by an etching process. A hard mask, such as a layer of silicon nitride or carbon, may be first formed on the recording layer and a patterned resist formed on the hard mask. The resist pattern is then transferred into the hard mask, which is used as the etch mask to etch the recording layer and form the discrete data islands. After the data islands are formed by the etching process, the patterned recording layer is annealed. The annealing may be done in a vacuum, or in an inert gas, like helium or argon, or in a forming gas such as a reducing atmosphere of argon plus hydrogen. The annealing improves the coercivity, the effective saturation magnetization and the thermal stability of the patterned media.
摘要:
A patterned perpendicular magnetic recording disk has a Co-alloy recording layer patterned into discrete data islands arranged in concentric tracks and exhibits a narrow switching field distribution (SFD). The disk includes a substrate, a NiTa alloy planarizing layer on the substrate, a nonmagnetic Ru-containing underlayer on the planarizing layer, an oxide-free Co alloy magnetic recording layer, and an ultrathin oxide film between the Ru-containing layer and the Co-alloy magnetic recording layer. The oxide film may be an oxide selected from a Ta-oxide, a Co-oxide and a Ti-oxide, and is ultrathin so that it may be considered a discontinuous film. The planarizing layer and ultrathin oxide film improve the growth homogeneity of the Co-alloy recording layer, so that the patterned disk with data islands shows significantly reduced SFD.
摘要:
A patterned perpendicular magnetic recording disk with discrete data islands of recording layer (RL) material includes a substrate, a patterned exchange bridge layer of magnetic material between the substrate and the islands, and an optional exchange-coupling control layer (CCL) between the exchange bridge layer and the islands. The exchange bridge layer has patterned pedestals below the islands. The exchange bridge layer controls exchange interactions between the RLs in adjacent islands to compensate the dipolar fields between islands, and the pedestals concentrate the flux from the write head. The disk may include a soft underlayer (SUL) of soft magnetically permeable material on the substrate and a nonmagnetic exchange break layer (EBL) on the SUL between the SUL and the exchange bridge layer. In a thermally-assisted recording (TAR) disk a heat sink layer may be located below the exchange bridge layer and the SUL may be optional.
摘要:
A patterned perpendicular magnetic recording disk has a Co-alloy recording layer patterned into discrete data islands arranged in concentric tracks and exhibits a narrow switching field distribution (SFD). The disk includes a substrate, a NiTa alloy planarizing layer on the substrate, a nonmagnetic Ru-containing underlayer on the planarizing layer, an oxide-free Co alloy magnetic recording layer, and an ultrathin oxide film between the Ru-containing layer and the Co-alloy magnetic recording layer. The oxide film may be an oxide selected from a Ta-oxide, a Co-oxide and a Ti-oxide, and is ultrathin so that it may be considered a discontinuous film. The planarizing layer and ultrathin oxide film improve the growth homogeneity of the Co-alloy recording layer, so that the patterned disk with data islands shows significantly reduced SFD.
摘要:
A patterned perpendicular magnetic recording disk with discrete data islands of recording layer (RL) material includes a substrate, a patterned exchange bridge layer of magnetic material between the substrate and the islands, and an optional exchange-coupling control layer (CCL) between the exchange bridge layer and the islands. The exchange bridge layer has patterned pedestals below the islands. The exchange bridge layer controls exchange interactions between the RLs in adjacent islands to compensate the dipolar fields between islands, and the pedestals concentrate the flux from the write head. The disk may include a soft underlayer (SUL) of soft magnetically permeable material on the substrate and a nonmagnetic exchange break layer (EBL) on the SUL between the SUL and the exchange bridge layer. In a thermally-assisted recording (TAR) disk a heat sink layer may be located below the exchange bridge layer and the SUL may be optional.
摘要:
A method for making a bit-patterned-media (BPM) magnetic recording disk includes depositing a FePt (or CoPt) alloy recording layer, and then depositing a sealing layer on the FePt layer before high-temperature annealing. The high-temperature annealing causes the FePt to become substantially chemically-ordered in the L10 phase. After annealing, the sealing layer is removed. The sealing layer prevents nanoclustering and agglomeration of the FePt material at the surface of the FePt layer and the sealing layer, which would result in undesirable high surface roughness of the FePt, making patterning of the FePt layer difficult. The FePt layer can be patterned into the discrete islands for the BPM disk either before deposition of the sealing layer or after deposition and removal of the sealing layer. After patterning and removal of the sealing layer, the disk protective overcoat is deposited over the discrete data islands.
摘要:
A method for making a bit-patterned-media (BPM) magnetic recording disk includes depositing a FePt (or CoPt) alloy recording layer, and then depositing a sealing layer on the FePt layer before high-temperature annealing. The high-temperature annealing causes the FePt to become substantially chemically-ordered in the L10 phase. After annealing, the sealing layer is removed. The sealing layer prevents nanoclustering and agglomeration of the FePt material at the surface of the FePt layer and the sealing layer, which would result in undesirable high surface roughness of the FePt, making patterning of the FePt layer difficult. The FePt layer can be patterned into the discrete islands for the BPM disk either before deposition of the sealing layer or after deposition and removal of the sealing layer. After patterning and removal of the sealing layer, the disk protective overcoat is deposited over the discrete data islands.
摘要:
A bit-patterned media (BPM) magnetic recording disk has discrete data islands with an exchange-coupled composite (ECC) recording layer (RL) formed of a high-anisotropy chemically-ordered FePt alloy lower layer, a lower-anisotropy Co/X laminate or multilayer (ML) upper layer with perpendicular magnetic anisotropy, wherein X is Pt, Pd or Ni, and an optional nonmagnetic separation layer or coupling layer (CL) between the FePt layer and the ML. The FePt alloy layer is sputter deposited onto a seed layer structure, like a CrRu/Pt bilayer, while the disk substrate is maintained at an elevated temperature to assure the high anisotropy field Hk is achieved. The high-temperature deposition together with the CrRu/Pt seed layer structure provide a very smooth surface for subsequent deposition of the ML (and optional CL). The separate Co/X ML has by itself a very narrow switching field distribution (SFD), so that the SFD of the ECC RL is much narrower than the SFD for the FePt layer alone.
摘要:
A thermally-assisted recording (TAR) patterned-media magnetic recording disk drive has a perpendicular patterned-media disk with multilevel data islands and a laser capable of supplying multiple levels of output power to a near-field transducer (NFT). If there are only two cells in each island, each island is formed of an upper cell of magnetic material with a coercivity HC1 and a Curie temperature TC1, a lower cell of magnetic material with a coercivity HC2 and a Curie temperature TC2 greater than TC1, and a nonmagnetic spacer layer between the two cells. Each cell is formed of high-anisotropy material so as to have an anisotropy field greater than the magnetic write field. The TAR laser is capable of supplying at least two levels of output power to the NFT to allow the islands to be heated to two distinct temperatures so that the two cells in an island can be written so as to have either the same or opposite magnetizations.