Hitachi Global Storage Technologies Netherlands B.v.

Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Victor Company of Japan, Limited

Hgst Netherlands, B.v.

The University of Alabama

Koichi Nishioka

Shuichi Kojima

Satoshi Shigematsu

Takayoshi Ohtsu

Koji Sakamoto

Daniele Mauri

Jinshan Li

Takao Imagawa

Makoto Morijiri

Wen-yaung Lee

Norifumi Miyamoto

Akira Morinaga

Yasunari Tajima

Katsuhisa Usami

Masatoshi Arasawa

Hiroshi Kamio

Haruko Tanaka

Masayasu Kagawa

Hideo Fujiwara

Yo Sato

Naoki Koyama

Katsumi Hoshino

Hideki Mashima

Masashi Hattori

Takayuki Iseki

Tsutomu Yasuda

Kouji Okazaki

Koji Kataoka

Tatsumi Hirano

Hiroaki Chihaya

Katsuya Mitsuoka

Azusa Hori

Yukimasa Okada

In an embodiment of the invention, a trilayer magnetoresistive sensor comprises an underlayer on which a first free layer is deposited. A barrier layer is then deposited after which a second free layer is deposited. A capping layer is then deposited above second free layer. The first free layer is a layer which includes at least a layer of a nitride of an element including at least one of Fe, Co, or Ni, or a multiple laminate structure of a layer containing a nitride of an element including at least one of Fe, Co, Ni and another ferromagnetic layer containing at least one of Fe, Co, or Ni. The combination of the first and second free layers causes anti-parallel coupling.

Half metal trilayer TMR reader with negative interlayer coupling

According to one embodiment, a method for producing a Tunneling Magnetoresistance (TMR) read head includes forming a fixed layer, forming an insulating barrier layer above the fixed layer, forming a free layer above the insulating barrier layer, and annealing the free layer, the fixed layer, and the insulating barrier layer. The fixed layer includes a first ferromagnetic layer having a CoFe (0&#x2266;x&#x2266;15) interface layer and a Co-based amorphous metallic layer between the CoFe interface layer and the insulating barrier layer, an antiparallel coupling layer below the first ferromagnetic layer, and a second ferromagnetic layer below the antiparallel coupling layer. In another embodiment, a TMR read head includes the layers described above, and may be included in a magnetic data storage system.

Tunneling magnetoresistance read head having a cofe interface layer and methods for producing the same

In one embodiment, a magnetic head includes a magnetoresistive free layer, wherein a width of the free layer nearest an air bearing surface (ABS) is less than a width of the free layer at a point away from the ABS in a track width direction, with the magnetic head being configured to pass a sense current in a direction perpendicular to a plane of deposition of the free layer. In another embodiment, a method includes forming a magnetoresistive film above a shield, forming a masking layer above the magnetoresistive film, patterning the masking layer such that it exposes portions of the magnetoresistive film, wherein the masking layer defines an area which is narrow near an area that forms an ABS side of a free layer and wider at an area away from the ABS, and removing the exposed portions of the magnetoresistive film to form the free layer.

Magnetic head with wide sensor back edge, low resistance, and high signal to-noise ratio and methods of production thereof

According to one embodiment, a TMR effect element includes a ground layer, an antiferromagnetic layer above the ground layer, a first ferromagnetic layer above the antiferromagnetic layer and exchange-coupled to the antiferromagnetic layer, an anti-parallel coupling layer above the first ferromagnetic layer, a second ferromagnetic layer having a magnetic moment coupled anti-parallel to the magnetic moment of the first ferromagnetic layer via the anti-parallel coupling layer, an insulation barrier layer above the second ferromagnetic layer, and a third ferromagnetic layer above the insulation barrier layer. At least a portion of the second ferromagnetic layer and at least a portion of the third ferromagnetic layer on an insulation barrier layer side are comprised of a crystal, and the insulation barrier layer comprises MgO and an oxide material having an independent cubic crystal structure and complete solid solubility with MgO. Other elements, heads, and formation methods are described according to various embodiments.

Tunneling junction magnetoresistive effect element and manufacturing method thereof

As recording density of sensors is increased, it is desired to lower the areal resistivity (RA) of TMR sensors. Decreasing RA to 1.0 &#x3a9;&#x3bc;mor below badly influences the read signal since the interlayer coupling magnetic field (Hint) between the pinned layer and the free layer increases sharply and impedes the free rotation of magnetization of the free layer. According to one embodiment, a tunnel junction type magneto-resistive head solves this problem by having a layered film comprising an underlying layer, a crystalline orientation control layer, an antiferromagnetic layer, a first ferromagnetic layer, an antiparallel coupling layer, a second ferromagnetic layer, an insulation barrier layer, and a third ferromagnetic layer between a lower magnetic shield layer and an upper magnetic shield layer, wherein a crystallographic plane of the antiferromagnetic layer is directed parallel to a film surface by growing the antiferromagnetic layer substantially conformably on the crystalline orientation control layer.

Tunnel junction type magneto-resistive head

One general embodiment of the present invention is a magnetic read head including a magnetoresistive sensor where sense current flows in a stacking direction of the magnetoresistive sensor, i.e., perpendicular to the plane of the layers of the head. The magnetoresistive sensor comprises a free layer having a magnetization direction that is affected by external magnetic fields and includes a Heusler alloy layer and a Co-based amorphous metal layer, a fixed layer which is stacked with the free layer and has a fixed magnetization direction, and a non-magnetic intermediate layer between the free layer and the fixed layer.

Current perpendicular to plane (CPP) magnetic read head

A tunnel magnetoresistance effect magnetic head having between magnetic shield layers, an antiferromagnetic layer, a pinned layer which has the direction of magnetization pinned by exchange coupling with the antiferromagnetic layer, an insulating layer, and a free layer whose direction of magnetization rotates relatively to external magnetic fields, wherein the antiferromagnetic layer is of an antiferromagnetic substance composed mainly of IrMn, the pinned layer is made up of a first pinned layer of CoFe alloy in contact with the antiferromagnetic layer and a second pinned layer of CoFeB alloy which is antiferromagnetically coupled with the first pinned layer, and the first and second pinned layers have the amount of magnetization such that the difference M1&#x2212;M2 is in the range of 0&#x3c;M2&#x2212;M1&#x3c;0.5 (nm&#xb7;T) and also have the magnetostriction constants such that the difference |&#x3bb;1&#x2212;&#x3bb;2| is no larger than 5.0&#xd7;10.

Magnetic head of magnetoresistance effect type with high resistance to external stress

An anti-parallel pinned sensor is provided with a spacer that increases the anti-parallel coupling strength of the sensor. The anti-parallel pinned sensor is a GMR or TMR sensor having a pure ruthenium or ruthenium alloy spacer. The thickness of the spacer is less than 0.8 nm, preferably between 0.1 and 0.6 nm. The spacer is also annealed in a magnetic field that is 1.5 Tesla or higher, and preferably greater than 5 Tesla. This design yields unexpected results by more than tripling the pinning field over that of typical AP-pinned GMR and TMR sensors that utilize ruthenium spacers which are 0.8 nm thick and annealed in a relatively low magnetic field of approximately 1.3 Tesla.

Enhanced anti-parallel-pinned sensor using thin ruthenium spacer and high magnetic field annealing

Embodiments of the invention provide a reading head structure that ensures a stable magnetic moment of a pinned layer against a great external magnetic field, and minimizes the pinned-layer damage occurring during air-bearing surface machining. In one embodiment, a magnetoresistive head is based on a spin-valve effect and has free layers, a stacked-type pinned layer, and an electroconductive nonmagnetic spacer layer positioned between the free layers and the stacked-type pinned layer. The stacked-type pinned layer includes three ferromagnetic films, and antiferromagnetic coupling films interposed between the ferromagnetic films. Of these ferromagnetic films, the first two films have a high coercivity and a high resistivity. The third ferromagnetic film is made of a material that gives a great magnetoresistive effect. The sum of the magnetic moments generated from the stacked-type pinned layer is substantially zero.

Magnetoresistive head and read/write separation-type magnetic head

A magneto-resistive effect head including: an antiferromagnetic layer; a pinned layer which is formed on the antiferromagnetic layer and whose magnetizing direction has been fixed; a spacer formed on the pinned layer; a free layer formed on the spacer; and magnetic domain control layers having antiferromagnetic flims and magnet layers for performing a magnetic domain control of the free layer; wherein the each of the antiferromagnetjc films is formed on the free layer; wherein the each of magnet layers has at least two magnetic films coupled anti-ferromagnetically through at least one nonmagnetic film; a pair of lead layers for supplying a current to the stack of layers; and wherein seed layers are formed between the antiferromagnetic films and the lead layers.

Magnetic head with magnetic domain control structure having anti-ferromagnetic layer and plural magnetic layers

A magnetoresistive head in which a pinned layer comprises two films, i.e., a ferromagnetic film A and a ferromagnetic B anti-ferromagnetically coupled to each other and a anti-ferromagnetic coupling film for separating the two ferromagnetic films A and B, where the coercivity of the ferromagnetic film alone is 200 (Oe) or more and the coercivity of the ferromagnetic film alone is 20 (Oe) or less. The compositions for the ferromagnetic film A and the ferromagnetic film B, when expressed by CoFe(at %) are: ferromagnetic film A: 80&#x2267;Y&#x2267;40, and ferromagnetic film B: 20&#x2267;Y&#x2267;0, where the material for the film in contact with the ferromagnetic film A is Ru, Ta, NiFeCr, Cu or NiFe.

Magnetoresistive head and manufacturing method thereof

Multiple thin films of spin-valve GMR sensor are formed in a trapezoidal cross-sectional shape by laminating an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic conductive layer, a free magnetic layer and a nonmagnetic protective layer on a lower insulated gap layer. The amount of etching of the lower insulated gap layer produced in the process of patterning the spin-valve giant magnetoresistive layers into the multiple thin films of spin-valve GMR sensor is 10 nm or less. Further, the angle &#x3b8; which the tangent line of each side face of the multiple thin films to the middle line of the free magnetic layer in its thickness direction forms with respect to the middle line of the free magnetic layer becomes 45 degrees or more. This structure makes it possible to provide such a spin-valve giant magnetoresistive head that it meets the requirements for securing constant breakdown voltage and preventing instability of MR output voltage waveform.

Method of manufacturing a spin-valve giant magnetoresistive head

As to a magnetic tunnel junction magneto-resistive head, which comprises an antiferromagnetic layer, a pinned ferromagnetic layer adjacent to said antiferromagnetic layer and magnetically pinned by a magnetization of said antiferromagnetic layer, a free ferromagnetic layer which is magnetically free from the magnetization of said antiferromagnetic layer, insulating layers sandwiched by these ferromagnetic layers, a stacked layers of ferromagnetic layers to control the magnetic domain of said free ferromagnetic layer and a pair of electrodes to apply a current to these layers and films, said stacked layers of ferromagnetic layers are formed between said free ferromagnetic layer and one of said electrodes. According to this composition, it is possible to present a magnetic tunnel junction magneto-resistive sensor with preferable domain controlling force against the free ferromagnetic layer.

Magnetic head and tunnel junction magneto-resistive head having plural ferromagnetic layers associated with an antiferromagnetic coupling layer for magnetically biasing the sensing free layer

The invention provides a magnetic domain controlling structure wherein a lamination stack Madjacent to a magnetoresistive stack of a GMR, CPP-GMR or TMR magnetic head has at least two magnetic filmsandanti-ferromagnetically coupled through a non-magnetic film, or the lamination stack Mdisposed on the end portions of the free layer of the magnetoresistive stack of the GMR magnetic head has a magnetic layer anti-ferromagnetically coupled to the free layerthrough the non-magnetic film. Ferromagnetic film deposition dead zone area problems and the consequent problem of film rippling in free layer portions that reduces element sensitivity are prevented, as is the problem of increased error from read drift in the magnetic field exchange coupling method, resulting in a highly stable, highly sensitive MR head with no loss of magnetic field intensity.

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Hiratsuka, Japan

Koichi Nishioka