Showa Denko K.k.

Tohoku University

Kabushiki Kaisha Toshiba

Toshiba Corporation

Yuzo Sasaki

Atsushi Hashimoto

Gohei Kurokawa

Tomoyuki Maeda

Akihiko Takeo

Migaku Takahashi

Shin Saito

Tetsuya Kanbe

Shinichi Ishibashi

Tatsu Komatsuda

Ryuji Sakaguchi

Kenji Suzuki

Shingo Sasaki

Susumu Sugano

In order to reduce edge defects efficiently and sufficiently, a method for manufacturing a SiC epitaxial wafer according to the present invention is a method for manufacturing a SiC epitaxial wafer that forms a SiC epitaxial layer on top of a SiC single crystal substrate having an off angle, and includes a rough polishing step for subjecting an outer circumferential edge on a starting side of step-flow growth in the SiC single crystal substrate to rough polishing before forming the SiC epitaxial layer; and a final polishing step for further polishing for finish.

Method for manufacturing SiC epitaxial wafer and SiC epitaxial wafer

A method of manufacturing a SiC substrate of the invention includes at least an oxide film-forming process of forming an oxide film () to cover a surface () of the SiC substrate (); and a planarization process of polishing the SiC substrate () from an oxide film side () in accordance with a CMP method so as to remove the oxide film (), and of polishing the surface () of the SiC substrate () to planarize the surface ().

Method for producing SiC substrate

A method that includes at least a CMP step of subjecting both a Si surface () and a C surface () of an SiC substrate () to double-sided polishing using a CMP (Chemical Mechanical Polishing) method with a C surface/Si surface processing selectivity ratio of 3.0 or greater.

A method for manufacturing a SiC substrate is provided. The method includes: a sacrificial film-forming process of forming a sacrificial film on a surface of a SiC substrate in a film thickness that is equal to or greater than a maximum height difference of the surface; a sacrificial film planarization process of planarizing a surface of the sacrificial film by mechanical processing; and a SiC substrate planarization process of performing dry etching under conditions in which etching selectivity between the SiC substrate and the sacrificial film is in a range of 0.5 to 2.0 so as to remove the sacrificial film and so as to planarize the surface of the SiC substrate.

Method for manufacturing SiC substrate

There are provided a method for manufacturing a magnetic recording medium which is excellent in terms of both the recording and reproduction characteristics and the thermal fluctuation characteristics without reducing the density and hardness of the perpendicular magnetic layer; a magnetic recording medium; and a magnetic recording and reproducing apparatus with which an excellent recording density is achieved,

Method for manufacturing magnetic recording medium, magnetic recording medium, and magnetic recording and reproducing apparatus

A thermal-assist magnetic recording medium is provided which can accomplish a surface recording density of 1 Tbit/inch. The thermal-assist magnetic recording medium includes: a substrate; a plurality of underlying layers formed on the substrate; a first magnetic layer formed on the underlying layers; a coupling control layer formed on the first magnetic layer and formed of a ferromagnetic alloy; and a second magnetic layer formed on the coupling control layer. Here, Curie temperatures of the first magnetic layer and the second magnetic layer are higher than the Curie temperature of the coupling control layer, an anisotropy magnetic field of the first magnetic layer is greater than the anisotropy magnetic field of the second magnetic layer, and a saturation magnetic field has a minimum value at a temperature of 350&#xb0; C. or lower.

Thermal-assist magnetic recording medium and magnetic recording and reproducing apparatus

The present invention relates to a method for manufacturing a perpendicular magnetic recording medium including a nonmagnetic substrate, and at least a soft magnetic under layer, an orientation control layer, a magnetic recording layer constituted of two or more layers and a protective layer formed on the nonmagnetic substrate, the method including a step of forming a first magnetic recording layer having a granular structure constituted of ferromagnetic crystal grains and crystal grain boundaries made of a nonmagnetic oxide or nitride on the nonmagnetic substrate side, a step of forming a second magnetic recording layer constituted only of ferromagnetic crystal grains, a step of forming a surface unevenness control layer for decreasing surface unevenness of the first magnetic recording layer located between the first magnetic recording layer and the second magnetic recording layer, and a step of heating the nonmagnetic substrate so as to decrease a surface roughness Ra of the second magnetic recording layer to less than 2 nm. The present invention also relates to a magnetic recording and reproducing apparatus using the magnetic recording medium.

Method for manufacturing magnetic recording layer having two or more layers

A perpendicular magnetic recording medium including at least a soft under layer, an orientation control layer, a magnetic recording layer and a protective layer on a non-magnetic substrate, wherein the orientation control layer is composed of three or more layers including a seed layer, a first intermediate layer and a second intermediate layer sequentially, formed in that order from the substrate side, the crystal grains that constitute the first intermediate layer are epitaxially grown on the crystal grains of the seed layer, the crystal grains that constitute the second intermediate layer are epitaxially grown on the crystal grains of the first intermediate layer, and the crystal grains that constitute the second intermediate layer are finer than the crystal grains that constitute the first intermediate layer.

Perpendicular magnetic recording medium, method for producing the same, and magnetic recording/reproducing device

There is provided a manufacturing method of a magnetic recording medium that maintains a high level of perpendicular orientation of a perpendicular magnetic layer and enables to further increase high recording density, prepared such that at least on a non-magnetic substrate, there are laminated a soft magnetic base layer, an orientation control layerthat controls the orientation of the layer immediately thereabove, and a perpendicular magnetic layer with a magnetization easy axis thereof primarily oriented perpendicular to the non-magnetic substrate. The manufacturing method is characterized in that when configuring the perpendicular magnetic layer with two or more magnetic layerstoand crystal-growing each layer so that the crystal grains that constitute the respective magnetic layersto, together with the crystal grains that constitute the orientation control layer, form column-shaped crystals Sto Sin a consecutive manner in the thickness direction, lamination of the orientation control layeris performed while the substrate is being cooled or immediately after the substrate has been cooled.

Manufacturing method of magnetic recording medium and magnetic recording/reproducing apparatus

The present invention relates to a perpendicular magnetic recording medium including a nonmagnetic substrate, and at least a soft magnetic layer (SUL), an alignment control layer, a magnetic recording layer and a protective layer formed on the nonmagnetic substrate, wherein the magnetic recording layer is constituted of two or more layers and includes a first magnetic recording layer and a second magnetic recording layer from the nonmagnetic substrate side and, regarding magnetocrystalline anisotropic energy Kof each magnetic recording layer, the first magnetic recording layer has 4&#xd7;10erg/cc or higher and the second magnetic recording layer has 2&#xd7;10erg/cc or lower, wherein the first magnetic recording layer is constituted of CoCrPtRu magnetic alloy crystal grains and grain boundaries made of an oxide and the area of grain boundaries is 30% or more based on the entire area in a planar TEM observation of the first magnetic recording layer. The present invention also relates to a magnetic recording and reproducing apparatus using the perpendicular magnetic recording medium.

Perpendicular magnetic recording medium and magnetic recording and reproducing apparatus

A heat-assisted magnetic recording medium that includes a substrate, underlayers formed on the substrate, and a magnetic layer which is formed on the underlayers and contains either an FePt alloy having an L1structure or a CoPt alloy having an L1structure as a main component, wherein the underlayers include a first underlayer formed from an amorphous alloy, a second underlayer formed from an alloy having a BCC structure containing Cr as a main component and also containing at least one element selected from among Ti, Mo, W, V, Mn and Ru, and a third underlayer formed from MgO. Also, a magnetic storage device that uses the heat-assisted magnetic recording medium.

Heat-assisted magnetic recording medium and magnetic storage device

The present invention relates to a perpendicular magnetic recording medium including a nonmagnetic substrate, and at least a soft magnetic layer (SUL), an alignment control layer, a magnetic recording layer and a protective layer formed on the nonmagnetic substrate; wherein the magnetic recording layer is constituted of three or more layers and includes a first magnetic recording layer, a second magnetic recording layer and a third magnetic recording layer from the substrate side, and also includes an exchange coupling reduction layer for reducing exchange coupling of both layers between the second magnetic recording layer and the third magnetic recording layer and, regarding magnetocrystalline anisotropic energy Kof each magnetic recording layer, the first magnetic recording layer has 4&#xd7;10erg/cc or higher, the second magnetic recording layer has 2&#xd7;10erg/cc or lower and the third magnetic recording layer has 1&#xd7;10erg/cc or lower. The present invention also relates to a magnetic recording and reproducing apparatus using the perpendicular magnetic recording medium.

A magnetic recording medium is provided which can record and reproduce high-density information by maintaining perpendicular orientation of a magnetic recording layer even with a decrease in thickness of nonmagnetic layers from an intermediate layer to a seed layer while decreasing the grain size of magnetic crystal grains to be consistent with an increase in recording density. A manufacturing method thereof and a magnetic recording and reproducing apparatus are also provided. The magnetic recording medium is a perpendicular magnetic recording medium including at least an underlying layer, an orientation control layer, a magnetic recording layer, and a protective layer formed on a nonmagnetic substrate. Here, the orientation control layer includes two or more layers of a seed layer and an intermediate layer from the substrate side. Materials of the seed layer and the intermediate layer are selected so that a contact angle of the intermediate layer material with respect to the seed layer material, which is amorphous, is in the range of 10 to 100 degrees.

Magnetic recording medium and magnetic recording and reproducing apparatus

In a perpendicular magnetic recording medium in which at least a soft magnetic underlayer, an orientation control layer, a magnetic recording layer and a protective layer are formed on a non-magnetic substrate in order from the bottom, the orientation control layer has a laminated structure of two or more layers including an intermediate layer and a seed layer which is disposed closer to the non-magnetic substrate than the intermediate layer. The seed layer includes two or more kinds of elements having a face-centered cubic structure, has face-centered cubic (111) plane crystals oriented in a direction perpendicular to a substrate surface, and has a pseudo-hexagonal structure.

Magnetic recording medium, method of manufacturing magnetic recording medium and magnetic recording reproducing apparatus

The present invention provides a magnetic recording medium which is capable of improving the perpendicular orientation of a perpendicular magnetic recording layer while maintaining a writing performance during recording and obtaining both an improvement in the perpendicular orientation and fine magnetic crystal particles with a uniform diameter, and which enables information to be recorded or reproduced at high density, a method of manufacturing the same, and a magnetic recording/reproducing apparatus. A magnetic recording mediumaccording to the present invention includes at least a soft magnetic underlayer, an orientation control layer, a magnetic recording layer, and a protective layerformed on a non-magnetic substrate. The orientation control layerhas a seed layerand an intermediate layer. The seed layeris made of a Cu&#x2014;Ti alloy that has a face-centered cubic structure and includes Cu as a main component. The Cu&#x2014;Ti alloy has a (111) crystal plane oriented substantially perpendicular to the surface of the non-magnetic substrateand has a pseudo-hexagonal structure.

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Ichihara, Japan

Yuzo Sasaki