Wd Media (Singapore) Pte. Ltd.

Hoya Corporation

Hoya Magnetics Singapore Pte. Ltd.

Wd Media, LLC

Other

Teiichiro Umezawa

Masafumi Ishiyama

Kenji Ayama

Hiroshi Tomiyasu

Yoshiaki Sonobe

Tokichiro Sato

Takahiro Onoue

Takashi Morikawa

Masato Kobayashi

Junichi Horikawa

Kong Kim

Koichi Wago

Masaki Uemura

Hisao Kawai

Kazuaki Sakamoto

Genshichi Hata

Tsuyoshi Watanabe

Hirotaka Tanaka

Keiji Moroishi

Masashi Suzuki

Satoshi Yokota

Takenori Kajiwara

Tomotaka Yokoyama

Toshiaki Tachibana

Shinichi Ishibashi

Chikara Takasu

Provided is a mask blank in which a thin film for transfer pattern formation is provided on a main surface of a transparent substrate. The thin film is made of a material containing a transition metal and silicon and further containing at least one of oxygen and nitrogen. The thin film has as its surface layer an oxide layer with an oxygen content higher than that of the thin film of a region other than the surface layer. The thin film is formed so that the thickness of its outer peripheral portion is greater than that of its central portion on the main surface side. The oxide layer is formed so that the thickness of its outer peripheral portion is greater than that of its central portion on the main surface side.

Mask blank and transfer mask

Mask blank, transfer mask, and methods of manufacturing the same

[Problem] A perpendicular magnetic disk with an improved SNR and an increased recording density by further improving crystal orientation of a preliminary ground layer formed of an Ni-base alloy is provided. [Solution] A typical structure of the perpendicular magnetic disk according to the present invention includes, on a base, a soft magnetic layer, a Ta alloy layerprovided on the soft magnetic layer, an Ni alloy layerprovided on the Ta alloy layer, a ground layerprovided on the Ni alloy layerand having Ru as a main component, and a granular magnetic layerprovided on the ground layer. The Ta alloy layeris a layer containing 10 atomic percent or more and 45 atomic percent or less Ta and having amorphous and soft magnetic properties.

Perpendicular magnetic recording disc

A perpendicular magnetic disk is provided. The disk includes, on a base and in the order from bottom, a first granular magnetic layer group including a plurality of magnetic layers each having a granular structure, a non-magnetic layer having Ru or a Ru alloy as a main component, a second granular magnetic layer group including a plurality of magnetic layers each having the granular structure, and an auxiliary recording layer having a CoCrPtRu alloy as a main component. Layers closer to a front surface among the plurality of magnetic layers included in the first granular magnetic layer group having an equal or smaller content of Pt. Layers closer to the front surface among the plurality of magnetic layers included in the second granular magnetic layer group having an equal or smaller content of Pt and having an equal or larger content of an oxide.

A perpendicular magnetic recording medium includes a substrate, a soft magnetic layer, a pre-underlayer, an underlayer, and a main recording layer serving as a magnetic recording layer. The pre-underlayer contains seed crystal grains that serve as a base for crystal grains of the underlayer, and an addition substance that is added between the seed crystal grains and composed of an element having an atomic radius smaller than that of an element forming the seed crystal grains.

Perpendicular magnetic recording medium and method of manufacturing the same

An object of the present invention is to provide a perpendicular magnetic recording medium the SNR of which is further improved while a high coercive force Hc is secured so that a higher recoding density can be achieved. The structure of a perpendicular magnetic recording mediumaccording to the present invention includes, on a base, at least a first magnetic recording layerhaving a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a non-magnetic split layercontaining Ru disposed on the first magnetic layer; and a second magnetic recording layerthat is disposed on the split layer and that has a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape, wherein the first magnetic layer and the second magnetic layer contain oxides that form the grain boundary, and when an oxide content of the first magnetic layer is represented by A and an oxide content of the second magnetic layer is represented by B, a relationship between the oxide contents A/B is in the range of 0.5&#x3c;A/B&#x3c;1.0.

Perpendicular magnetic recording medium

A method for manufacturing a magnetic recording medium includes the steps of (a) forming a perpendicular magnetic recording layer and (b) applying an ion beam to regions between tracks of the perpendicular magnetic recording layer so as to form separation regions for magnetically separating the tracks from each other. In the step (a), a continuous film layer composed of a multilayer film is formed, and CoB layers and Pd layers are laminated in the multilayer film. In the step (b), the CoB layers and the Pd layers are melted by the ion beam so as to form an alloy of metals contained in the CoB layers and the Pd layers to thereby form the separation regions.

Method for manufacturing magnetic recording medium

A perpendicular magnetic recording medium with SNR improved by reducing noise due to an auxiliary recording layer so that a higher recording density can be achieved. The perpendicular magnetic recording mediumincludes a base, at least a magnetic recording layerhaving a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a non-magnetic split layerdisposed on the magnetic recording layerand containing Ru and oxygen; and an auxiliary recording layerthat is disposed on the split layerand that is magnetically approximately continuous in an in-plane direction of a main surface of the base

Perpendicular magnetic recording medium and process for manufacture thereof

A perpendicular magnetic recording medium of the invention is characterized by having, on a disk substrate, a soft magnetic layer, a magnetic recording layer, a continuous layermagnetically continuous in the in-plane direction of the substrate, a blocking layerfor blocking shock imposed on the continuous layer, and a medium protective layercontaining carbon formed on the blocking layer.

Perpendicular magnetic recording medium and manufacturing method of the same

An object of the present invention is to increase an electromagnetic transducing characteristic (in particular, SNR) by further promoting separation and isolation of magnetic grains of a magnetic recording layer () in a perpendicular magnetic recording medium (). Thus, a typical structure of the perpendicular magnetic recording medium () according to the present invention includes, on a substrate (), at least a non-magnetic granular layer () having a granular structure in which a grain boundary part including one or a plurality of oxides is formed between non-magnetic grains each continuously grown in a columnar shape and a magnetic recording layer () formed continuously with the non-magnetic granular layer () and having a granular structure in which a grain boundary part including one or a plurality of oxides is formed between magnetic grains continuously grown in a columnar shape in this order, and at least one oxide included in the grain boundary part of the non-magnetic granular layer () and at least one oxide included in the grain boundary part of the magnetic recording layer () are oxides of a same composition.

An object of the present invention is to provide a method of manufacturing a perpendicular magnetic recording medium () in which both of a coercive force Hc and reliability can be achieved at a higher level even with heating at the time of forming a medium protective layer () and to provide the perpendicular magnetic recording medium (). Thus, in a typical structure of the present invention, in the method of manufacturing the perpendicular magnetic recording medium () including at least a magnetic recording layer (), which is a ferromagnetic layer of a granular structure in which a non-magnetic grain boundary part is formed between crystal grains each grown in a columnar shape, and a medium protective layer () with carbon hydride as a main component in this order on a disk base (), the method includes a magnetic recording layer forming step of forming the magnetic recording layer () so that the grain boundary part contains oxides of a plurality of types and a medium protective layer forming step of forming the medium protective layer () in a state where the disk base () having the magnetic recording layer () formed thereon is heated at 160 to 200 degrees Celsius.

Method of manufacturing perpendicular magnetic recording medium and perpendicular magnetic recording medium

A magnetic diskfor use in perpendicular magnetic recording has at least a magnetic recording layer on a substrate. The magnetic recording layer is composed of a ferromagnetic layerof a granular structure containing silicon (Si) or an oxide of silicon (Si) between crystal grains containing cobalt (Co), a stacked layerhaving a first layer containing cobalt (Co) or a Co alloy and a second layer containing palladium (Pd) or platinum (Pt), and a spacer layerinterposed between the ferromagnetic layerand the stacked layer. After forming the ferromagnetic layeron the substrateby sputtering in an argon gas atmosphere, the stacked layeris formed by sputtering in the argon gas atmosphere at a gas pressure lower than that used when forming the ferromagnetic layer

Perpendicular magnetic recording disk and manufacturing method thereof

A perpendicular magnetic disk that includes, a base, a granular magnetic layer, and a auxiliary recording layerdisposed as an upper layer of the granular magnetic layer. The granular magnetic layerhas a granular structure in which a grain boundary portion is formed by segregation of a non-magnetic substance containing an oxide as a main component around magnetic particles containing a CoCrPt alloy grown in a columnar shape as a main component. The auxiliary recording layercontains a CoCrPtRu alloy as a main component and has a film thickness of 1.5 nm to 4.0 nm. With this structure, the auxiliary recording layer can be thinned while maintaining the function thereof to improve SNR.

Perpendicular magnetic disc

A method for manufacturing a magnetic recording medium for perpendicular magnetic recording includes the steps of forming a first magnetic layer which has magnetic crystal grains exhibiting perpendicular magnetic anisotropy and nonmagnetic substances for magnetically separating the magnetic crystal grains from each other at grain boundaries of the magnetic crystal grains, forming a second magnetic layer which has magnetic grains exchange-coupled to the magnetic crystal grains, a grain boundary width of the magnetic grains being smaller than a grain boundary width of the magnetic crystal grains, and forming separation regions which magnetically separate tracks from each other in regions between the tracks of the magnetic recording medium in at least the second magnetic layer. The separation regions are disposed substantially only in the second magnetic layer of the first magnetic layer and the second magnetic layer.

Magnetic recording medium having patterned auxiliary recording layer and method for manufacturing such magnetic recording medium

A vertical magnetic recording disc () includes a base (), a magnetic recording layer (), and a medium protection layer (). The magnetic recording layer () is a ferromagnetic layer having a granular structure where a granular portion is formed. The medium protection layer () contains nitrogen (N) atoms and carbon (C) atoms with a number ratio (N/C) in a range from 0.050 to 0.150. In a Raman spectrum obtained by exciting the medium protection layer () by argon ion laser light of wavelength 514.5 nm, from which a fluorescence is removed, the peak ratio Dh/Gh is in a range from 0.70 to 0.95, when a D peak Dh appearing in the vicinity of 1350 cmis separated from G peak Gh appearing in the vicinity of 1520 cmby the Gauss function.

Growing community of inventors

Singapore, Singapore

Teiichiro Umezawa