Hitachi, Ltd.

Hitachi Global Storage Technologies Netherlands B.v.

Hitachi Global Storage Technologies Japan, Ltd.

Shuichi Kojima

Koichi Nishioka

Norihiro Ookawa

Masatoshi Arasawa

Akira Kato

Naoki Koyama

Yoshinori Honda

Takayoshi Ohtsu

Akira Morinaga

Shinji Fukaya

Koji Okazaki

Masayasu Kagawa

Satoshi Shigematsu

Makoto Morijiri

Norifumi Miyamoto

Haruko Tanaka

Izuru Ishii

Kouji Okazaki

Hiroshi Fukui

Shigekazu Otomo

Hiromi Shiina

Shigeru Tadokoro

Gen Oikawa

Noriyuki Saiki

Kouji Kataoka

Harunobu Saito

Yasunari Tajima

Wataru Kimura

Koji Kataoka

Azusa Hori

Yukimasa Okada

Akira Kondo

Kenji Ishikake

Yasunobu Yanagisawa

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

In one embodiment, a seed layer, an underlayer, and a magnetic domain control layer are laminated on both sides of a magnetoresistive sheet unit. A lower electrode film is thinly formed on an upper portion of the magnetic domain control film. A portion of the lower electrode film near the magnetoresistive sheet unit does not protrude substantially from an upper surface of the magnetoresistive sheet unit. Should the portion protrude, a step from the upper surface of the magnetoresistive sheet unit is about 14 nm or less. This portion and the upper surface of the magnetoresistive sheet unit are formed into a flat surface. An upper electrode film is formed thickly on an upper portion of the lower electrode film on an outside thereof so as to circumvent the flat surface. A protective layer, an upper gap film, and an upper magnetic shield film are also formed.

Magnetoresistive head and fabricating method thereof, and read write separation type head

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

Even if the track and gap widths are made narrow in a read head, a narrow track head has so far been unable to afford satisfactory off-track characteristics because of a wide shield spacing over electrodes. The invention provides a magnetic head wherein, in the height direction of a magnetoresistive element, the spacing between an upper magnetic shield and a lower magnetic shield at an air bearing surface is narrower than the spacing between the upper and lower magnetic shields formed over a thickest portion of each of electrodes in contact with associated magnetic domain control layers.

Magnetic head with a narrow spacing between magnetic shields at air bearing surface

Making thinner the magnetic domain control layer deteriorates the magnetic properties. Also, disturbances tend to increase the magnetization dispersion of the magnetic domain control layer, thereby lowering the magnetic domain control bias magnetic field. In one embodiment of the invention, a first magnetic domain control layer is provided in the proximity of the free layer of the GMR sensor in such a way that the track width is Twr. Outside the first magnetic domain control layer is provided a second magnetic domain control layer. The second magnetic domain control layer placed outside the first magnetic domain control layer gives the first magnetic domain control layer an external bias field. The amount of magnetization of the tip of the first magnetic domain control layer is polarized and increased by the bias magnetic field from the second magnetic domain control layer. This causes the first magnetic domain control layer to apply a strong bias magnetic field having a lower dispersion to the free layer of the GMR sensor.

Magnetoresistive head, with second magnetic domain control layers and manufacturing method thereof

In formation of an upper shield of a magnetic thin film head by electroplating, a current density of electroplating is regulated stepwise with time. Thus, in the upper shield formation, a film composition and magnetic characteristic with respect to the direction of film thickness can be controlled precisely, making it possible to provide a magnetic thin film head featuring significantly reduced noise-after-write and output fluctuation.

Magnetic thin film head, the fabrication method, and magnetic disk

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 magnetic domain control underlayer is formed below a magnetoresistive multi-layered film thereby bringing the magnetic domain control film into contact with both lateral end faces of a free layer and appropriate magnetic domain control can be attained in a state of minimizing a surplus bias magnetic field from the magnetic domain control film.

Magnetoresistive head having magnetic domain control film in contact with underlayer and with ends of free layer

In a magnetoresistive head according to the present invention, a magnetic domain control film formed at the end of a free layer of a stack of magnetoresistive layers is formed of a Co alloy film, and an underlayer controlling the crystallization state of the Co alloy film and an amorphous metal film layer for controlling the crystallization state of the underlayer are disposed below the magnetic domain control film.

Magnetoresistive sensor with random crystal orientation underlayer and magnetic domain control film center aligned with free layer

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

A recording/reproducing separated type magnetic head comprising a first magnetic domain control layer for arranging the magnetizing direction of a free layer included in a magneto-resistive element to a predetermined direction, and a second magnetic domain control layer for generating a magnetic field in the direction opposite thereto to constitute a differential type bias structure. The recording/reproducing separated type magnetic head decreases an excessively strengthened longitudinal bias magnetic field in a central portion at a narrow track width while avoiding decrease of the fixed magnetic field at the end of the magneto-resistive element in the direction of the track width.

Recording/reproducing separated type magnetic head having differential bias type magnetic domain control structure

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.

Magnetic head with a lamination stack to control the magnetic domain

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 &thgr; 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.

Spin-valve giant magnetoresistive head and method of manufacturing the same

A magnetic recording has very low warp characteristics but excellent film characteristics. Particularly, the recording medium has a high coercivity with a small range of coercivity distribution, with a warp characteristic below 3 .mu.m per radial inch. The medium is formed by heating a substrate at a high temperature with a temperature distribution on the substrate that is improved by the use of a heat distribution mask, which reduces the temperature distribution of the substrate to below .+-.3%.

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Hiratsuka, Japan

Shuichi Kojima