Fuji Electric Co., Ltd.

Tomohiro Moriya

Takehito Shimatsu

Hitoshi Nakata

Akira Furuta

Shinji Uchida

Hiroyasu Kataoka

Hiroto Kikuchi

Hirohisa Oyama

Tsuyoshi Yoshizawa

A semiconductor device includes n-type drift layer, n-type current spreading layer having higher impurity concentration than the drift layer, p-type base region provided on top surface, p-type gate-bottom protection region located in the current spreading layer, having first bottom edge portion formed of curved surface, p-type base-bottom embedded region in contact with bottom surface of the base region, having second bottom edge portion formed of curved surface on side surface facing the gate-bottom protection region, being separated from the gate-bottom protection region, and insulated gate electrode structure provided in trench penetrating through the base region to reach the gate-bottom protection region. Bottom surface of the base-bottom embedded region is deeper than bottom surface of the gate-bottom protection region, and minimum value of curvature radius of the first bottom edge portion is larger than minimum value of curvature radius of the second bottom edge portion.

Semiconductor device

A magnetic recording medium with a reduced average grain diameter and reduced grain diameter dispersion is provided. A magnetic recording medium having a magnetic property (magnetic anisotropy energy) applicable as a magnetic recording medium is provided. It is a magnetic recording medium containing a substrate, a grain diameter control layer, a first seed layer, a second seed layer, and a magnetic recording layer containing an ordered alloy in this order, in which the second seed layer is composed of crystal grains having TiN as a main component, and a grain boundary material having at least one or more selected from the group consisting of metal oxides and carbon as a main component.

Magnetic recording medium having tin containing seed layer

The invention provides a magnetic recording medium including a magnetic layer or a magnetic recording layer having a granular structure in which magnetic crystal grains are well separated from each other. The magnetic recording medium includes a substrate, a seed layer, and a magnetic recording layer, wherein the magnetic recording layer includes a first magnetic layer which is a continuous film consisting of an ordered alloy, and a second magnetic layer having a granular structure consisting of magnetic crystal grains consisting of an ordered alloy and a non-magnetic crystal grain boundary, and the seed layer consists of a material selected from the group consisting of an NaCl-type compound, a spinel-type compound, and a perovskite-type compound.

Magnetic recording medium having magnetic layer with a granular structure

The purpose of the present invention is to provide a magnetic recording medium having a stacked structure of a seed layer including (MgTi)O and a magnetic recording layer including an L1ordered alloy, and having improved properties. The method for producing a magnetic recording layer according to the present invention includes the steps of: (1) preparing a substrate; (2) forming a seed layer including (MgTi)O onto the substrate; (3) plasma etching the seed layer in an atmosphere including inert gas; and (4) forming a magnetic recording layer including an ordered alloy onto the seed layer which has been subjected to the step (3).

Method for producing magnetic recording medium

The purpose of the present invention is to provide a perpendicular magnetic recording medium which uses an Ru seed layer having a (002)-oriented hcp structure, and has a magnetic recording layer including a (001)-oriented L1ordered alloy suitable to perpendicular magnetic recording. The magnetic recording medium of the present invention includes a substrate, a first seed layer containing Ru, a second seed layer containing ZnO, a third seed layer containing MgO, and a magnetic recording layer containing an ordered alloy, in this order, the first seed layer having the (002)-oriented hexagonal closest packed structure.

Magnetic recording medium

The present invention aims at providing a magnetic recording medium that can lower a Curie temperature (Tc) of a magnetic material, without increasing an in-plane coercive force and lowering magnetic properties. The magnetic recording medium is a magnetic recording medium comprising a substrate and a magnetic recording layer, the magnetic recording layer comprising an FePtRh ordered alloy, wherein a Rh content in the FePtRh ordered alloy is 10 at % or less.

Magnetic recording medium having an FePtRh magnetic layer

The purpose of the present invention is to provide a magnetic recording medium capable of reducing the surface roughness of the magnetic recording layer without adversely affecting the magnetic properties of the magnetic recording layer. The magnetic recording medium of the present invention includes a substrate, a seed layer on the substrate, and a magnetic recording layer on the seed layer, wherein the seed layer has a structure of: (a) a spinel structure consisting of Mg, Cr and O; (b) a spinel structure consisting of Zn, Fe and O; or (c) an inverse spinel structure consisting of Mg, Ti and O.

The present invention relates to a magnetic recording medium, and this magnetic recording medium includes at least a non-magnetic substrate and a magnetic recording layer. In the magnetic recording medium of the present invention, the magnetic recording layer includes an ordered alloy having an L1-ordered structure, includes Fe, Pt, and V, and has a composition of Pt&#x3e;Fe. The magnetic recording layer preferably has a granular structure composed of magnetic crystal grains including the ordered alloy and a non-magnetic crystal grain boundary, and the non-magnetic crystal grain boundary includes V.

Perpendicular magnetic recording medium

The purpose of the invention is to provide a magnetic recording medium in which the surface roughness of the magnetic recording layer can be reduced without deterioration of the magnetic properties of the magnetic recording layer. The magnetic recording medium of the present invention includes a substrate, a seed layer on the substrate, and a magnetic recording layer on the seed layer, wherein the seed layer contains Mn, Cr, and O, and has a spinel structure.

A magnetic recording medium is provided that includes, in the order recited, a substrate; a first seed layer; a second seed layer containing ZnO; a third seed layer containing MgO; and a magnetic recording layer containing an ordered alloy. The first seed layer contains Ru and at least one material selected from the group consisting of oxides, carbides, and nitrides. Employing seed layers enables the magnetic recording medium to be a perpendicular magnetic recording medium by having the magnetic recording layer contain an ordered alloy suitable for perpendicular magnetic recording. Recording density is improved thereby while ensuring required thermal stability. Further, the invention achieves an increased thickness of the magnetic layer and a reduced grain size.

Magnetic recording medium and method for producing the same

The present invention provides a magnetic recording layer that has a high magnetic anisotropy constant Ku and a low Curie temperature Tc, as well as a magnetic recording medium that incorporates such a magnetic recording layer. The magnetic recording medium of the present invention includes a nonmagnetic substrate and a magnetic recording layer containing an ordered alloy. The ordered alloy may contain at least one element selected from the group consisting of Fe and Ni; at least one element selected from the group consisting of Pt, Pd, Au, Rh and Ir; and Ru.

The purpose of the present invention is to provide a magnetic recording medium including a magnetic recording layer having more excellent magnetic properties and including an L1type ordered alloy. One constitutional example of the magnetic recording medium includes a substrate, a first seed layer comprising ZnO, a second seed layer comprising MgO, and a magnetic recording layer comprising an ordered alloy, in this order.

A magnetic recording medium having a thick magnetic recording layer of excellent magnetic characteristics is provided. The magnetic recording medium includes a non-magnetic substrate and a magnetic recording layer. The magnetic recording layer includes a plurality of first magnetic recording layers located at odd-numbered positions from the non-magnetic substrate, and one or more second magnetic recording layers located at even-numbered positions from the non-magnetic substrate. The first magnetic recording layers each have a granular structure that has first magnetic crystal grains with an ordered alloy and a first non-magnetic portion surrounding the first magnetic crystal grains and formed of a material having carbon as main component. The second magnetic recording layers each have a granular structure that has second magnetic crystal grains with an ordered alloy and a second non-magnetic portion surrounding the second magnetic crystal grains and formed of a material different from that of the first non-magnetic portion.

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Matsumoto, Japan

Tomohiro Moriya