Hitachi Global Storage Technologies Netherlands B.v.

International Business Machines Corporation

Hgst Netherlands, B.v.

David Thomas Margulies

Eric Edward Fullerton

Hoa Van Do

Natacha Frederique Supper

Hal Jervis Rosen

Ernesto Esteban Marinero

Byron Hassberg Lengsfield, Iii

Mary Frances Doerner

Andreas Moser

Manfred Ernst Schabes

Olav Hellwig

Andreas Klaus Berger

Bruce Alvin Gurney

Matthew Joseph Carey

Brian Rodrick York

Kurt A Rubin

Jan-Ulrich Thiele

Tim Minvielle

Kai Tang

Elizabeth Ann Dobisz

Xiao Z Wu

Yoshihiro Ikeda

James Aloysius Hagan

Philip M Rice

Timothy Martin Reith

Ronald Franklin Marks

Ren Xu

Robin Frederick Charles Farrow

Qing Dai

Xiaoping Bian

Kentaro Takano

Qi-Fan Xiao

Mary Frances Minardi

Min Xiao

William G McChesney

Andreas K Berger

Methods of fabricating perpendicular magnetic recording media are disclosed. The multilayer structures of the perpendicular magnetic recording media are fabricated by varying the sputtering conditions (i.e., pressure, sputtering gas, etc) in a single sputtering module so that multiple sputtering modules are not needed to form the multilayer structures. These fabrication methods allow sputtering tools with a limited number of chambers, which were designed for the manufacture of longitudinal media, to be used to efficiently produce perpendicular media architectures which heretofore required a large number of sputtering modules. It is further shown that media structures involving a geometric weak-link architecture are suited for these fabrication techniques.

Generation of multilayer structures in a single sputtering module of a multi-station magnetic recording media fabrication tool

Patterned media and associated methods of fabrication are provided in which vertical magnetic grains are grown on a patterned seed layer. The patterned seed layer includes a matrix of islands of a first seed material. Each island of first seed material is separated from other islands by a region of second seed material. The first seed material is selected to initiate growth of magnetic material, and the second seed material is selected to initiate growth of non-magnetic material. Subsequently, magnetic material is grown on the first seed material and non-magnetic material is grown on the second seed material. Deposition may be simultaneously. The magnetic and non-magnetic materials form well-defined vertical columns over the first and second seed materials respectively. Thus, each island behaves as an isolated magnetic unit, which switches independently from its neighbor units, which are magnetically separated by the non-magnetic material.

Fabricating magnetic recording media on patterned seed layers

A laminated magnetic recording structure for use in perpendicular or longitudinal recording is described. A small amount of ferromagnetic coupling is added between the two magnetic layers that are sufficiently decoupled to switch independently. In one embodiment the coupling is achieved by doping the spacer layer with a ferromagnetic material. Ruthenium (Ru), which is a preferred nonmagnetic material for spacer layers with cobalt (Co) being the preferred magnetic material. The weak ferromagnetic coupling can also be achieved through the use of platinum, palladium and alloys thereof for the spacer layer without the addition of a ferromagnetic element, but alternatively they can also be doped with ferromagnetic elements. For embodiments for perpendicular recording the spacer layer further can additionally comprise oxides of one or more elements selected from the group consisting of Si, Ta, Ti, Nb, Cr, V and B.

Laminated magnetic thin films for magnetic recording with weak ferromagnetic coupling

The invention includes a disk drive with a magnetic recording disk with an upper and lower sublayer in at least one magnetic layer of a laminated magnetic layer structure that includes a spacer layer that substantially decouples the magnetic layers. The lower sublayer has a lower boron content than the upper sublayer and a preferred embodiment is CoPtCrBTa. The upper sublayer is deposited onto the lower sublayer and is preferably CoPtCrB with a higher boron content than the lower sublayer. The composition of the lower sublayer gives it a very low moment with low intrinsic coercivity which would not be useful as a recording layer on its own. The upper sublayer is a higher moment alloy with high intrinsic coercivity. An embodiment of the invention includes a laminated magnetic layer structure which is antiferromagnetically coupled to a lower ferromagnetic layer.

Disk drive with laminated magnetic thin films with sublayers for magnetic recording

An improved structure for the construction of perpendicular recording media is disclosed. The structure includes a perpendicular recording layer with at least two oxide sublayers or a lower sublayer of a non-oxide. One structure includes an upper sublayer comprised of a Silicon-oxide, while a lower sublayer is comprised of a Tantalum-oxide. The structures provide for increased coercivity and corrosion resistance.

Oxide magnetic recording layers for perpendicular recording media

A perpendicular magnetic recording system and medium has a multilayered recording layer that includes an exchange-spring structure and a ferromagnetic lateral coupling layer (LCL). The exchange-spring structure is made up of two ferromagnetically exchange-coupled magnetic layers (MAGand MAG), each with perpendicular magnetic anisotropy. MAGand MAGmay have a coupling layer (CL) located between them that permits ferromagnetic exchange coupling of MAGwith MAG. The LCL is located either above or below MAGand in direct contact with MAGand mediates an effective intergranular exchange coupling in MAG. The ferromagnetic alloy in the LCL has significantly greater intergranular exchange coupling than the ferromagnetic alloy in MAG, which typically will include segregants such as oxides. The LCL is preferably free of oxides or other non-metallic segregants, which would tend to reduce intergranular exchange coupling in the LCL. Because the LCL grain boundaries overlay the boundaries of the generally segregated and decoupled grains of MAG, and the LCL and MAGgrains are strongly coupled perpendicularly, the LCL introduces an effective intergranular exchange coupling in the MAG

Perpendicular magnetic recording exchange-spring type medium with a lateral coupling layer for increasing intergranular exchange coupling in the lower magnetic layer

A perpendicular magnetic recording disk has an antiferromagnetically-coupled (AFC) recording layer (RL) comprised of lower and upper ferromagnetic layers, each having a hexagonal-close-packed (hcp) crystalline structure and perpendicular magnetic anisotropy, separated by an antiferromagnetically (AF) coupling layer, wherein the lower ferromagnetic layer (LFM) has substantially higher magnetic permeability than the upper ferromagnetic layer (UFM). The AFC RL is located on an actual exchange break layer (EBL) that separates the AFC RL from the disk's soft magnetic underlayer (SUL). The LFM functions as part of an 'effective' exchange break layer (EBL) that also includes the actual EBL and the AF-coupling layer, thereby allowing the actual EBL to be made as thin as possible. The hcp LFM promotes the growth of the hcp UFM in the same way the actual EBL does so that its thickness contributes to the thickness necessary to grow the hcp UFM. The effective EBL appears to be magnetically 'thin' during the write process and magnetically &#x201c;thick&#x201d; during the readback process.

Perpendicular magnetic recording medium with improved antiferromagnetically-coupled recording layer

An embodiment of the invention is a layered magnetic thin film structure that uses antiferromagnetically coupled (AFC) magnetic layers where the top layer structure consists of an upper magnetic layer that is weakly ferromagnetically coupled via a nonmagnetic or weakly magnetic exchange coupling layer (interlayer) to a ferromagnetic exchange enhancing layer that is in turn, AF coupled to the lower ferromagnetic layer of the AFC structure. Preferred materials for the weak coupling layer include alloys of cobalt such as CoRu, CoBRu and CoCr in which the Co content is below the point at which the material would be ferromagnetic. A second embodiment of the invention is a laminated, AF-coupled media structure. In this structure the lower AFC layer that makes up the lower laminate layer includes: the middle magnetic layer, the weak ferromagnetic coupling layer, and the exchange enhancing layer.

Antiferromagnetically coupled media for magnetic recording with weak coupling layer

The invention uses an upper and lower magnetic layer of a laminated magnetic layer structure that includes an AF spacer layer that results in weak antiferromagnetic coupling of the magnetic layers that is insufficient to cause either of the layers to switch so that the magnetic orientations of the two ferromagnetic layers remain parallel. An advantage of the invention is that the AF-coupling tends to anti-correlate the noise in the two layers. The weak AF coupling according to the invention is believed to act at the transition boundaries in the media to cause some of the noise domains to be oriented antiparallel and the noise to be less correlated than would be the case without the AF coupling and thereby to achieve improved SNR.

Laminated magnetic thin films with weak antiferromagnetic coupling for perpendicular magnetic recording

A laminated perpendicular magnetic recording medium has two recording layers (RLand RL) that are separated and magnetically decoupled by a nonmagnetic spacer layer (SL). The SL has a thickness and composition to assure there is no antiferromagnetic or ferromagnetic coupling between RLand RL. Thus in the presence of the write field, RLand RLrespond independently and become oriented with the direction of the write field. Each RL is an 'exchange-spring' type magnetic recording layer formed of two ferromagnetic layers (MAGand MAG) that have substantially perpendicular magnetic anisotropy and are ferromagnetically exchange-coupled by a nonmagnetic or weakly ferromagnetic coupling layer (CL). The medium takes advantage of lamination to attain higher signal-to-noise ratio (SNR) yet has improved writability as a result of each RL being an exchange-spring type RL.

Perpendicular magnetic recording medium with laminated recording layers formed of exchange-coupled ferromagnetic layers

A method and apparatus for improving the signal-to-noise ratio in a longitudinal recording media is disclosed. The apparatus includes a first recording layer of the longitudinal recording media residing at the top of a recording media structure. The first recording layer includes an upper sublayer comprised of a CoPtCrB-based alloy material. The first recording layer also includes a lower sublayer comprised of a CoPtCrB-based alloy material and a middle sublayer comprised of a CoCrB-alloy. The middle sublayer is coupled to the upper sublayer and to the lower sublayer and is substantially thinner than the upper sublayer and the lower sublayer.

Method and apparatus for improving signal-to-noise ratio in longitudinal recording media

A laminate structure is disclosed comprising multiple ferromagnetic layers achieving incoherent reversal while maintaining good SNR. A high magnetic moment density, low anisotropy field material may form a thin overlayer deposited over a high-anisotropy media layer. The media layer may have a lower magnetic moment density than the overlayer and have decoupled magnetic grains. A coupling layer may be interposed between the overlayer and the media layer to modulate the exchange there between, thereby reducing the pass-through of noise while still promoting incoherent reversal to achieve reduced write energy requirements.

Incoherently-reversing magnetic laminate with exchange coupled ferromagnetic layers

A magnetic recording medium has a laminated magnetic structure with at least three magnetic layers, wherein the magnetic layers have decreasing intrinsic coercivity Hwith distance from the write head. The write field at the center of each magnetic layer is greater than that layer's H. The magnetic layers have different compositions and/or thicknesses and thereby different values of H. The alloys used in the middle and upper magnetic layers are relatively 'high-moment' alloys that would not ordinarily be used in magnetic recording media because they have relatively low SNR, but the overall SNR of the laminated magnetic structure is improved because of the effect of lamination. The middle and upper magnetic layers can be made substantially thinner, which enables the magnetic layers to be located closer to the write head, thereby exposing each of the magnetic layers to a higher write field.

Magnetic recording medium having three ferromagnetic layers with increasing intrinsic coercivity from the lower to the upper layer

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Los Gatos, CA, United States of America

David Thomas Margulies