US20050048328A1 - Magnetic thin film media with a bi-layer structure of crti/nip - Google Patents
Magnetic thin film media with a bi-layer structure of crti/nip Download PDFInfo
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- US20050048328A1 US20050048328A1 US10/651,634 US65163403A US2005048328A1 US 20050048328 A1 US20050048328 A1 US 20050048328A1 US 65163403 A US65163403 A US 65163403A US 2005048328 A1 US2005048328 A1 US 2005048328A1
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- 230000005291 magnetic effect Effects 0.000 title claims abstract description 48
- 239000010409 thin film Substances 0.000 title claims abstract description 39
- 239000000758 substrate Substances 0.000 claims abstract description 23
- 239000011651 chromium Substances 0.000 claims abstract description 15
- 239000011521 glass Substances 0.000 claims abstract description 11
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 10
- 238000000034 method Methods 0.000 claims description 8
- 229910000599 Cr alloy Inorganic materials 0.000 claims description 6
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 5
- 238000000151 deposition Methods 0.000 claims description 5
- 229910052698 phosphorus Inorganic materials 0.000 claims description 5
- 239000011574 phosphorus Substances 0.000 claims description 5
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 4
- 239000000788 chromium alloy Substances 0.000 claims description 4
- 239000010936 titanium Substances 0.000 claims description 4
- 229910052719 titanium Inorganic materials 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 238000003860 storage Methods 0.000 claims 8
- 230000001590 oxidative effect Effects 0.000 claims 1
- UMUXBDSQTCDPJZ-UHFFFAOYSA-N chromium titanium Chemical compound [Ti].[Cr] UMUXBDSQTCDPJZ-UHFFFAOYSA-N 0.000 abstract description 30
- 229910000531 Co alloy Inorganic materials 0.000 abstract description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 2
- 229910052760 oxygen Inorganic materials 0.000 abstract description 2
- 239000001301 oxygen Substances 0.000 abstract description 2
- OFNHPGDEEMZPFG-UHFFFAOYSA-N phosphanylidynenickel Chemical compound [P].[Ni] OFNHPGDEEMZPFG-UHFFFAOYSA-N 0.000 abstract description 2
- 239000010408 film Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 5
- YTPMCWYIRHLEGM-BQYQJAHWSA-N 1-[(e)-2-propylsulfonylethenyl]sulfonylpropane Chemical compound CCCS(=O)(=O)\C=C\S(=O)(=O)CCC YTPMCWYIRHLEGM-BQYQJAHWSA-N 0.000 description 4
- 229910000684 Cobalt-chrome Inorganic materials 0.000 description 3
- 239000010952 cobalt-chrome Substances 0.000 description 3
- 230000005294 ferromagnetic effect Effects 0.000 description 3
- 125000006850 spacer group Chemical group 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910001004 magnetic alloy Inorganic materials 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 229910001149 41xx steel Inorganic materials 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- 230000005290 antiferromagnetic effect Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 239000002178 crystalline material Substances 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000007772 electroless plating Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000003302 ferromagnetic material Substances 0.000 description 1
- 239000002241 glass-ceramic Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- 238000006748 scratching Methods 0.000 description 1
- 230000002393 scratching effect Effects 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 238000012876 topography Methods 0.000 description 1
Images
Classifications
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
- G11B5/739—Magnetic recording media substrates
- G11B5/73911—Inorganic substrates
- G11B5/73921—Glass or ceramic substrates
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
- G11B5/7368—Non-polymeric layer under the lowermost magnetic recording layer
- G11B5/7369—Two or more non-magnetic underlayers, e.g. seed layers or barrier layers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/90—Magnetic feature
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12465—All metal or with adjacent metals having magnetic properties, or preformed fiber orientation coordinate with shape
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12771—Transition metal-base component
- Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
- Y10T428/12826—Group VIB metal-base component
- Y10T428/12847—Cr-base component
- Y10T428/12854—Next to Co-, Fe-, or Ni-base component
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12771—Transition metal-base component
- Y10T428/12861—Group VIII or IB metal-base component
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12986—Adjacent functionally defined components
Definitions
- the invention relates to magnetic thin film media and methods for their fabrication and more particularly to materials for use in magnetic thin film disks prior to an underlayer.
- FIG. 1 A typical prior art head and disk system 10 is illustrated in FIG. 1 .
- the magnetic transducer 20 is supported by the suspension 13 as it flies above the disk 16 .
- the magnetic transducer 20 usually called a “head” or “slider,” is composed of elements that perform the task of writing magnetic transitions (the write head 23 ) and reading the magnetic transitions (the read head 12 ).
- the electrical signals to and from the read and write heads 12 , 23 travel along conductive paths (leads) 14 which are attached to or embedded in the suspension 13 .
- the magnetic transducer 20 is positioned over points at varying radial distances from the center of the disk 16 to read and write circular tracks (not shown).
- the disk 16 is attached to a spindle 18 that is driven by a spindle motor 24 to rotate the disk 16 .
- the disk 16 comprises a substrate 26 on which a plurality of thin films 21 are deposited.
- the thin films 21 include ferromagnetic material in which the write head 23 records the magnetic transitions in which information is encoded.
- the substrate was AlMg with an amorphous NiP surface film deposited by wet electroless plating.
- the AlMg/NiP disk was considered to be the substrate on which thin films were vacuum deposited to form the layers of the magnetic media.
- One embodiment of the thin films 21 typically used with a glass substrate includes an amorphous initial thin film which is called a pre-seed layer and is followed by a crystalline seed layer.
- a pre-seed layer typically both the pre-seed layer and seed layer are relatively thin layers.
- a crystalline CrTi seed layer is described.
- a chromium or chromium alloy underlayer such as Cr, CrV and CrTi.
- ferromagnetic layers based on various alloys of cobalt follow the underlayer.
- a commonly used alloy is CoPtCr. Additional elements such as tantalum and boron are also often used in the magnetic alloy.
- a protective overcoat layer is used to improve wearability and corrosion resistance.
- the disk embodiment described above is one of many possibilities. For example, multiple seed layers, multiple underlayers and multiple magnetic layers have all been proposed in the prior art.
- U.S. Pat. No. 6,567,236 to Doemer, et al. describes a preferred embodiment of a layer structure as: an amorphous pre-seed layer of CrTi, a seed layer of RuAl, a crystalline underlayer of CrTi, a bottom ferromagnetic layer of CoCr, an antiferromagnetic coupling/spacer layer of Ru; and a top ferromagnetic structure including: a thin first sublayer of CoCr, CoCrB or CoPtCrB, and a thicker second sublayer of CoPtCrB with a lower moment than the first sublayer.
- U.S. Pat. No. 5,879,783 to Chang, et al. describes the use of a NiP seed layer which is sputtered deposited on a glass or glass-ceramic substrate, and the surface is roughened by oxidation.
- a magnetic recording medium is described that includes a seed layer comprising a material selected from the group consisting of oxidized NiP (NiPOx) and CrTi.
- the thickness of the seed layer is said to be about 4 nm to 6 nm. It is stated that the CrTi and NiPOx seed layers enhance the development of CoTi/Cr(200) and Co(11.0) crystallographic orientation, and help to reduce grain size of CoTi/Cr-alloy underlayers.
- the preferred orientation (PO) of the various crystalline materials forming the layers on the disk is not necessarily an exclusive orientation which may be found in the material, but is merely the most prominent orientation.
- a [200] PO is usually formed.
- This PO promotes the epitaxial growth of [11-20] PO of the hexagonal close-packed (hcp) cobalt (Co) alloy, and thereby improves the magnetic performance of the disk.
- the [11-20] PO refers to a film of hexagonal structure whose (11-20) planes are predominantly parallel to the surface of the film.
- the [10-10] PO refers to a film of hexagonal structure whose (10-10) planes are predominantly parallel to the surface of the film.
- the [10-10] PO can be epitaxially grown on an appropriate underlayer with a PO of [112].
- the applicants disclose a thin film magnetic media structure with a bi-layer structure of amorphous chromium titanium (CrTi) followed by an amorphous layer of nickel phosphorus (NiP) deposited prior to the underlayer. After the NiP has been deposited it is preferably exposed to oxygen to form an oxidized surface. Preferably the underlayer is deposited directly onto the oxidized NiP surface.
- the bi-layer structure of CrTi/NiP promotes excellent in-plane crystallographic orientation in the cobalt alloy magnetic layer(s) and allows an ultra-thin chromium underlayer to be used which provides better control over grain size and distribution.
- a high Mrt orientation ratio (OR) results.
- FIG. 1 is a symbolic illustration of the prior art showing the relationships between the head and associated components in a disk drive.
- FIG. 2 is an illustration of a thin film layer stack for a magnetic thin film disk embodying the CrTi/NiP bi-layer structure of the invention.
- FIG. 3 is an illustration of an embodiment of a magnetic thin film layer structure for use in the layer stack of FIG. 2 .
- the bi-layer structure described herein is composed of two amorphous or nanocrystalline layers. The structure is particularly suited to use on circumferentially textured substrates since it helps achieve a good in-plane c-axis orientation, as well as, a high orientation ratio.
- FIG. 2 illustrate the thin film layers in a magnetic film disk 16 embodying the invention.
- the substrate 26 is preferably glass, but can be any other appropriate material. Even more preferably the substrate is circumferentially textured glass.
- the CrTi layer 31 is vacuum deposited directly onto the substrate surface 26 .
- the NiP layer 32 is vacuum deposited onto the CrTi layer 31 . These layers are preferably deposited at room temperature and without substrate voltage bias.
- the CrTi layer and NiP layers will be referred to collectively as the CrTi/NiP bi-layer structure.
- the surface of the NiP is oxidized by supplying oxygen gas into the deposition chamber or by breaking vacuum and exposing the surface to the atmosphere.
- the underlayer 33 is vacuum deposited directly onto NiP.
- the underlayer is preferably chromium, but can also be a chromium alloy.
- the bi-layer structure of the invention allows the underlayer 33 to be kept very thin.
- the advantage of having an ultra-thin underlayer is that control over the grain size and distribution is improved. In general, the thinner the underlayer, the smaller the spread in grain sizes.
- the magnetic layer structure 34 is followed by a protective overcoat layer 35 .
- the preferred range for the combined thickness of the CrTi/NiP bi-layer structure and the underlayer is from 60 to 150 anstroms.
- one embodiment of the invention has a 20 angstrom CrTi layer, a 45 angstrom NiP layer and a 40 angstrom chromium underlayer for a combined thickness of 105 angstroms. This is to be compared with an embodiment from the U.S. Pat. No. 6,593,009 issued to Bian, et al. of 200 angstroms CrTi, 60 angstroms RuAl and 60 angstroms of a CrTi underlayer.
- the bi-layer structure of the invention can be used with a wide range of magnetic layer structures 34 .
- the magnetic layer structure 34 can be a single magnetic layer or it can comprise a combination of multiple magnetic layers, spacer layers, onset layers, etc. as are known in the art.
- An antiferromagnetically coupled magnetic layer stack can also be used.
- FIG. 3 illustrates a particular embodiment of the magnetic layer structure 34 that can be used with the bi-layer structure of the invention.
- the functions of the onset layer 41 are described in the prior art. In this embodiment CrMo is preferred.
- the lower magnetic layer 42 is preferably CoCr.
- the spacer layer 43 is preferably ruthenium.
- the upper magnetic layer 44 is preferably CoPtCrB.
- the FWHM rocking curve measurements relate to the distribution of the crystallographic orientations. Lower values indicate a smaller (better) distribution of orientations.
- the CrTi/NiP bi-layer structure yielded smaller rocking curve values for both the Cr(200) orientation and the Co(11-20) orientation.
- the preferred compositional range for the CrTi layer is limited by the requirement that it remain amorphous; therefore, approximately from 45 to 55 at. % titanium should be used with 50 at. % being preferred.
- the preferred compositional range for NiP layer is from 15 to 25 at. % phosphorus which must likewise remain amorphous. NiP with 19 at. % phosphorus is particularly preferred.
- the atomic percent compositions are given without regard for the small amounts of contamination that invariably exist in sputtered thin films as is well known to those skilled in the art.
Abstract
Description
- The invention relates to magnetic thin film media and methods for their fabrication and more particularly to materials for use in magnetic thin film disks prior to an underlayer.
- A typical prior art head and
disk system 10 is illustrated inFIG. 1 . In operation themagnetic transducer 20 is supported by thesuspension 13 as it flies above thedisk 16. Themagnetic transducer 20, usually called a “head” or “slider,” is composed of elements that perform the task of writing magnetic transitions (the write head 23) and reading the magnetic transitions (the read head 12). The electrical signals to and from the read and writeheads suspension 13. Themagnetic transducer 20 is positioned over points at varying radial distances from the center of thedisk 16 to read and write circular tracks (not shown). Thedisk 16 is attached to aspindle 18 that is driven by aspindle motor 24 to rotate thedisk 16. Thedisk 16 comprises asubstrate 26 on which a plurality ofthin films 21 are deposited. Thethin films 21 include ferromagnetic material in which thewrite head 23 records the magnetic transitions in which information is encoded. Historically the substrate was AlMg with an amorphous NiP surface film deposited by wet electroless plating. The AlMg/NiP disk was considered to be the substrate on which thin films were vacuum deposited to form the layers of the magnetic media. - One embodiment of the
thin films 21 typically used with a glass substrate includes an amorphous initial thin film which is called a pre-seed layer and is followed by a crystalline seed layer. Typically both the pre-seed layer and seed layer are relatively thin layers. In U.S. Pat. No. 5,789,056 to Bian, et al., the use of a crystalline CrTi seed layer is described. Following the seed layer is typically a chromium or chromium alloy underlayer such as Cr, CrV and CrTi. One or more ferromagnetic layers based on various alloys of cobalt follow the underlayer. For example, a commonly used alloy is CoPtCr. Additional elements such as tantalum and boron are also often used in the magnetic alloy. A protective overcoat layer is used to improve wearability and corrosion resistance. The disk embodiment described above is one of many possibilities. For example, multiple seed layers, multiple underlayers and multiple magnetic layers have all been proposed in the prior art. - U.S. Pat. No. 6,593,009 issued to Bian, et al. on Jul. 15, 2003 describes a thin film magnetic media structure comprising a pre-seed layer CrTi which presents an amorphous or nanocrystalline structure. In the following text the term amorphous will be used to include nanocrystalline. The preferred seed layer is said to be RuAl. The use of the CrTi/RuAl bi-layer structure provides superior adhesion to the substrate and resistance to scratching, as well as, excellent coercivity and signal-to-noise ratio (SNR) and reduced cost over the prior art.
- U.S. Pat. No. 6,567,236 to Doemer, et al., describes a preferred embodiment of a layer structure as: an amorphous pre-seed layer of CrTi, a seed layer of RuAl, a crystalline underlayer of CrTi, a bottom ferromagnetic layer of CoCr, an antiferromagnetic coupling/spacer layer of Ru; and a top ferromagnetic structure including: a thin first sublayer of CoCr, CoCrB or CoPtCrB, and a thicker second sublayer of CoPtCrB with a lower moment than the first sublayer.
- U.S. Pat. No. 5,879,783 to Chang, et al., describes the use of a NiP seed layer which is sputtered deposited on a glass or glass-ceramic substrate, and the surface is roughened by oxidation. In U.S. Pat. No. 6,596,419 to Chen, et al., a magnetic recording medium is described that includes a seed layer comprising a material selected from the group consisting of oxidized NiP (NiPOx) and CrTi. The thickness of the seed layer is said to be about 4 nm to 6 nm. It is stated that the CrTi and NiPOx seed layers enhance the development of CoTi/Cr(200) and Co(11.0) crystallographic orientation, and help to reduce grain size of CoTi/Cr-alloy underlayers.
- The preferred orientation (PO) of the various crystalline materials forming the layers on the disk, as discussed herein, is not necessarily an exclusive orientation which may be found in the material, but is merely the most prominent orientation. When the Cr underlayer is sputter deposited at a sufficiently elevated temperature on a NiP-coated AlMg substrate a [200] PO is usually formed. This PO promotes the epitaxial growth of [11-20] PO of the hexagonal close-packed (hcp) cobalt (Co) alloy, and thereby improves the magnetic performance of the disk. The [11-20] PO refers to a film of hexagonal structure whose (11-20) planes are predominantly parallel to the surface of the film. Likewise the [10-10] PO refers to a film of hexagonal structure whose (10-10) planes are predominantly parallel to the surface of the film. The [10-10] PO can be epitaxially grown on an appropriate underlayer with a PO of [112].
- One technique used in the prior art to improve magnetic recording performance on thin film disks is circumferential polishing to create a pattern of fine “scratches” (circumferential texture) which are generally oriented along tracks (concentric circles) on the disk surface. The scale of the texture of commercial thin film disks is microscopic with a peak-to-valley of less than 5 nm typically. A 5 nm texture appears mirror-like to the untrained eye. Special polishing equipment is necessary to achieve circumferential texture this fine. The topography of the surface on which a thin film is deposited can have a significant effect on the way the film nucleates and grows and also upon its characteristics. So called circumferential texture on magnetic disks has been commonly used to influence the inplane magnetic anisotropy for a wide range of magnetic alloys. For longitudinal recording it is sometimes useful to have a higher coercivity (Hc) and Mrt in the circumferential direction than in the radial direction. The ratio of the circumferential Hc to the radial Hc is called the coercivity orientation ratio (OR). Similarly the ratio of the circumferential Mrt to the radial Mrt is called the Mrt orientation ratio (OR). Current disks typically use hexagonal close packed (hcp) cobalt alloys and most (but not all) circumferentially textured disks have an Hc or Mrt OR>1.
- The applicants disclose a thin film magnetic media structure with a bi-layer structure of amorphous chromium titanium (CrTi) followed by an amorphous layer of nickel phosphorus (NiP) deposited prior to the underlayer. After the NiP has been deposited it is preferably exposed to oxygen to form an oxidized surface. Preferably the underlayer is deposited directly onto the oxidized NiP surface. The bi-layer structure of CrTi/NiP promotes excellent in-plane crystallographic orientation in the cobalt alloy magnetic layer(s) and allows an ultra-thin chromium underlayer to be used which provides better control over grain size and distribution. When the CrTi/NiP bi-layer structure is combined with a circumferentially textured disk, preferably glass, a high Mrt orientation ratio (OR) results.
-
FIG. 1 is a symbolic illustration of the prior art showing the relationships between the head and associated components in a disk drive. -
FIG. 2 is an illustration of a thin film layer stack for a magnetic thin film disk embodying the CrTi/NiP bi-layer structure of the invention. -
FIG. 3 is an illustration of an embodiment of a magnetic thin film layer structure for use in the layer stack ofFIG. 2 . - For longitudinal media on glass or other nonmetallic substrates, it is important to maximize the c-axis in-plane crystallographic orientation and maintain the orientation ratio. Some seed layer materials contribute to good in-plane c-axis orientation when used on smooth or randomly polished substrates, but turn out not to be satisfactory for used on circumferential textured substrates because they produce a much lower orientation ratio (OR). The bi-layer structure described herein is composed of two amorphous or nanocrystalline layers. The structure is particularly suited to use on circumferentially textured substrates since it helps achieve a good in-plane c-axis orientation, as well as, a high orientation ratio.
- Reference is made to
FIG. 2 illustrate the thin film layers in amagnetic film disk 16 embodying the invention. In the embodiment shown inFIG. 2 thesubstrate 26 is preferably glass, but can be any other appropriate material. Even more preferably the substrate is circumferentially textured glass. TheCrTi layer 31 is vacuum deposited directly onto thesubstrate surface 26. The NiP layer 32 is vacuum deposited onto theCrTi layer 31. These layers are preferably deposited at room temperature and without substrate voltage bias. The CrTi layer and NiP layers will be referred to collectively as the CrTi/NiP bi-layer structure. After the NiP layer has been vacuum deposited, the surface of the NiP is oxidized by supplying oxygen gas into the deposition chamber or by breaking vacuum and exposing the surface to the atmosphere. After the NiP surface has been oxidized the underlayer 33 is vacuum deposited directly onto NiP. The underlayer is preferably chromium, but can also be a chromium alloy. The bi-layer structure of the invention allows the underlayer 33 to be kept very thin. The advantage of having an ultra-thin underlayer is that control over the grain size and distribution is improved. In general, the thinner the underlayer, the smaller the spread in grain sizes. Themagnetic layer structure 34 is followed by aprotective overcoat layer 35. - The preferred range for the combined thickness of the CrTi/NiP bi-layer structure and the underlayer is from 60 to 150 anstroms. As an illustration, one embodiment of the invention has a 20 angstrom CrTi layer, a 45 angstrom NiP layer and a 40 angstrom chromium underlayer for a combined thickness of 105 angstroms. This is to be compared with an embodiment from the U.S. Pat. No. 6,593,009 issued to Bian, et al. of 200 angstroms CrTi, 60 angstroms RuAl and 60 angstroms of a CrTi underlayer.
- The bi-layer structure of the invention can be used with a wide range of
magnetic layer structures 34. Themagnetic layer structure 34 can be a single magnetic layer or it can comprise a combination of multiple magnetic layers, spacer layers, onset layers, etc. as are known in the art. An antiferromagnetically coupled magnetic layer stack can also be used.FIG. 3 illustrates a particular embodiment of themagnetic layer structure 34 that can be used with the bi-layer structure of the invention. The functions of theonset layer 41 are described in the prior art. In this embodiment CrMo is preferred. The lowermagnetic layer 42 is preferably CoCr. Thespacer layer 43 is preferably ruthenium. The uppermagnetic layer 44 is preferably CoPtCrB. - In an experiment magnetic disks were prepared using NiP as a sole seed layer and the CrTi/NiP bi-layer structure of the invention. The underlayer was chromium and magnetic layer structures were as described above. The substrates were circumferentially textured glass. The measured results are given in Table 1.
TABLE 1 Cr(200) Co(11-20) Mrt Rocking Curve Rocking Curve Seed Mrt Hc OR tangential radial tangential radial CrTi/NiP 0.35 4100 2.0 6.6 12.9 6.0 10.4 NiP 0.36 3900 1.5 7.3 13.3 6.8 11.4
The Mrt orientation ratio (OR) was 1.5 for the NiP seed, but the CrTi/NiP of the invention yielded an Mrt OR 2.0. The higher OR is desirable. The FWHM rocking curve measurements relate to the distribution of the crystallographic orientations. Lower values indicate a smaller (better) distribution of orientations. The CrTi/NiP bi-layer structure yielded smaller rocking curve values for both the Cr(200) orientation and the Co(11-20) orientation. - The preferred compositional range for the CrTi layer is limited by the requirement that it remain amorphous; therefore, approximately from 45 to 55 at. % titanium should be used with 50 at. % being preferred. The preferred compositional range for NiP layer is from 15 to 25 at. % phosphorus which must likewise remain amorphous. NiP with 19 at. % phosphorus is particularly preferred. The atomic percent compositions are given without regard for the small amounts of contamination that invariably exist in sputtered thin films as is well known to those skilled in the art.
- The invention has been described with respect to particular embodiments, but other uses and applications for the seed layer structure of the invention will be apparent to those skilled in the art.
Claims (20)
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US10/651,634 US6858331B1 (en) | 2003-08-29 | 2003-08-29 | Magnetic thin film media with a bi-layer structure of CrTi/Nip |
CNB200410074912XA CN1288637C (en) | 2003-08-29 | 2004-08-30 | Magnetic thin film media with a bi-layer structure of CrTi/NiP |
JP2004249624A JP2005078796A (en) | 2003-08-29 | 2004-08-30 | MAGNETIC THIN FILM MEDIA WITH BI-LAYER STRUCTURE OF CrTi/NiP |
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US10/651,634 US6858331B1 (en) | 2003-08-29 | 2003-08-29 | Magnetic thin film media with a bi-layer structure of CrTi/Nip |
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US20050048328A1 true US20050048328A1 (en) | 2005-03-03 |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
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US20060046102A1 (en) * | 2004-08-31 | 2006-03-02 | Xiaoping Bian | Magnetic recording disk with antiferromagnetically coupled master layer including copper |
US8404369B2 (en) * | 2010-08-03 | 2013-03-26 | WD Media, LLC | Electroless coated disks for high temperature applications and methods of making the same |
US8585811B2 (en) | 2010-09-03 | 2013-11-19 | Omg Electronic Chemicals, Llc | Electroless nickel alloy plating bath and process for depositing thereof |
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US7407719B1 (en) * | 2003-12-24 | 2008-08-05 | Seagate Technology Llc | Longitudinal magnetic media having a granular magnetic layer |
JP4444182B2 (en) | 2005-07-26 | 2010-03-31 | 株式会社東芝 | Perpendicular magnetic recording medium tilted in the direction of easy magnetization, its manufacturing method, and magnetic recording / reproducing apparatus including the same |
JP4795831B2 (en) * | 2006-03-31 | 2011-10-19 | Hoya株式会社 | Magnetic recording medium |
EP2121992A4 (en) * | 2007-02-13 | 2015-07-08 | Univ Yale | Method for imprinting and erasing amorphous metal alloys |
Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5314745A (en) * | 1992-01-17 | 1994-05-24 | Kubota Corporation | Magnetic recording medium having a glass substrate, heat retaining non magnetic metal layer formed over the substrate, amorphous nip layer, Cr layer and magnetic layer |
US5733370A (en) * | 1996-01-16 | 1998-03-31 | Seagate Technology, Inc. | Method of manufacturing a bicrystal cluster magnetic recording medium |
US5798056A (en) * | 1995-02-01 | 1998-08-25 | Canon Kabushiki Kaisha | Aligning method of liquid crystal, production process of liquid crystal device, and liquid crystal device |
US5879783A (en) * | 1996-08-05 | 1999-03-09 | Seagate Technology, Inc. | Low noise magnetic recording medium and method of manufacturing |
US5922456A (en) * | 1996-09-04 | 1999-07-13 | Hitachi, Ltd. | Longitudal magnetic recording medium having a multi-layered underlayer and magnetic storage apparatus using such magnetic recording medium |
US5993956A (en) * | 1997-04-22 | 1999-11-30 | Carnegie Mellon University | Manganese containing layer for magnetic recording media |
US6001447A (en) * | 1997-02-21 | 1999-12-14 | Hitachi, Ltd. | Longitudinal magnetic recording media and magnetic storage apparatus using the same |
US6077603A (en) * | 1996-07-03 | 2000-06-20 | Seagate Technology, Inc. | Seeded underlayer in magnetic thin films |
US6077586A (en) * | 1997-07-15 | 2000-06-20 | International Business Machines Corporation | Laminated thin film disk for longitudinal recording |
US6316097B1 (en) * | 1998-09-28 | 2001-11-13 | Seagate Technology Llc | Electroless plating process for alternative memory disk substrates |
US20020048692A1 (en) * | 1999-07-12 | 2002-04-25 | Tetsuo Hosokawa | Disk medium and disk apparatus |
US6497925B1 (en) * | 1999-12-14 | 2002-12-24 | Seagate Technology Llc | Surface treatment on solgel coated substrate to improve glide height performance |
US20030059648A1 (en) * | 2001-09-26 | 2003-03-27 | Fujitsu Limited | Magnetic recording medium and method of producing the same |
US6567236B1 (en) * | 2001-11-09 | 2003-05-20 | International Business Machnes Corporation | Antiferromagnetically coupled thin films for magnetic recording |
US6596419B1 (en) * | 2000-09-27 | 2003-07-22 | Seagate Technology Llc | Medium with a seed layer and a B2-structured underlayer |
US20030219631A1 (en) * | 2002-05-22 | 2003-11-27 | Hitachi, Ltd. | Magnetic recording medium and method for manufacturing the same |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5789056A (en) | 1997-01-30 | 1998-08-04 | International Business Machines Corporation | Thin film magnetic disk with chromium-titanium seed layer |
-
2003
- 2003-08-29 US US10/651,634 patent/US6858331B1/en not_active Expired - Lifetime
-
2004
- 2004-08-30 JP JP2004249624A patent/JP2005078796A/en not_active Withdrawn
- 2004-08-30 CN CNB200410074912XA patent/CN1288637C/en not_active Expired - Fee Related
Patent Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5314745A (en) * | 1992-01-17 | 1994-05-24 | Kubota Corporation | Magnetic recording medium having a glass substrate, heat retaining non magnetic metal layer formed over the substrate, amorphous nip layer, Cr layer and magnetic layer |
US5798056A (en) * | 1995-02-01 | 1998-08-25 | Canon Kabushiki Kaisha | Aligning method of liquid crystal, production process of liquid crystal device, and liquid crystal device |
US5733370A (en) * | 1996-01-16 | 1998-03-31 | Seagate Technology, Inc. | Method of manufacturing a bicrystal cluster magnetic recording medium |
US6077603A (en) * | 1996-07-03 | 2000-06-20 | Seagate Technology, Inc. | Seeded underlayer in magnetic thin films |
US5879783A (en) * | 1996-08-05 | 1999-03-09 | Seagate Technology, Inc. | Low noise magnetic recording medium and method of manufacturing |
US5922456A (en) * | 1996-09-04 | 1999-07-13 | Hitachi, Ltd. | Longitudal magnetic recording medium having a multi-layered underlayer and magnetic storage apparatus using such magnetic recording medium |
US6001447A (en) * | 1997-02-21 | 1999-12-14 | Hitachi, Ltd. | Longitudinal magnetic recording media and magnetic storage apparatus using the same |
US5993956A (en) * | 1997-04-22 | 1999-11-30 | Carnegie Mellon University | Manganese containing layer for magnetic recording media |
US6077586A (en) * | 1997-07-15 | 2000-06-20 | International Business Machines Corporation | Laminated thin film disk for longitudinal recording |
US6316097B1 (en) * | 1998-09-28 | 2001-11-13 | Seagate Technology Llc | Electroless plating process for alternative memory disk substrates |
US20020048692A1 (en) * | 1999-07-12 | 2002-04-25 | Tetsuo Hosokawa | Disk medium and disk apparatus |
US6497925B1 (en) * | 1999-12-14 | 2002-12-24 | Seagate Technology Llc | Surface treatment on solgel coated substrate to improve glide height performance |
US6596419B1 (en) * | 2000-09-27 | 2003-07-22 | Seagate Technology Llc | Medium with a seed layer and a B2-structured underlayer |
US20030059648A1 (en) * | 2001-09-26 | 2003-03-27 | Fujitsu Limited | Magnetic recording medium and method of producing the same |
US6567236B1 (en) * | 2001-11-09 | 2003-05-20 | International Business Machnes Corporation | Antiferromagnetically coupled thin films for magnetic recording |
US20030219631A1 (en) * | 2002-05-22 | 2003-11-27 | Hitachi, Ltd. | Magnetic recording medium and method for manufacturing the same |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20060046102A1 (en) * | 2004-08-31 | 2006-03-02 | Xiaoping Bian | Magnetic recording disk with antiferromagnetically coupled master layer including copper |
US7419730B2 (en) * | 2004-08-31 | 2008-09-02 | Hitachi Global Storage Technologies Netherlands B.V. | Magnetic recording disk with antiferromagnetically coupled master layer including copper |
US8404369B2 (en) * | 2010-08-03 | 2013-03-26 | WD Media, LLC | Electroless coated disks for high temperature applications and methods of making the same |
US8828482B1 (en) | 2010-08-03 | 2014-09-09 | WD Media, LLC | Electroless coated disks for high temperature applications and methods of making the same |
US8585811B2 (en) | 2010-09-03 | 2013-11-19 | Omg Electronic Chemicals, Llc | Electroless nickel alloy plating bath and process for depositing thereof |
Also Published As
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US6858331B1 (en) | 2005-02-22 |
JP2005078796A (en) | 2005-03-24 |
CN1619650A (en) | 2005-05-25 |
CN1288637C (en) | 2006-12-06 |
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