Hmt Technology Corporation

Michael A Russak

Brij B Lal

Allen J Bourez

Sudhir S Malhotra

James L Chao

Ming M Yang

Bruce M Harper

Zhangmin Wang

Zhaoguo Jiang

Brij Bihari Lal

Protective overlayers for magnetic recording media are described. The overlayers, composed of a transition metal-silicon or transition metal-germanium interlayer and a carbon overcoat, provide good wear resistance and corrosion resistance at thicknesses of less than 100 &angst;.

Thin overlayer for magnetic recording disk

A magnetic recording medium having a dual underlayer structure is described. The underlayer structure is composed of a first underlayer of chromium and a second underlayer of a chromium alloy.

Longitudinal recording medium with a dual underlayer

A magnetic recording medium having a barrier layer deposited directly on the magnetic recording layer is described. The barrier layer is deposited by sputter deposition under a nitrogen-containing sputtering atmosphere to form a nitrogen-containing chromium or chromium alloy barrier layer. The barrier layer is effective to inhibit migration of cobalt from the underlying magnetic recording layer, reducing corrosion of the medium and improving magnetic recording performance.

Magnetic recording medium having a nitrogen-containing barrier layer

An improvement in a magnetic recording medium having an underlayer and first and second magnetic recording layers is described. The improvement, effective to reduce media noise, includes deposition of an interlayer between the first and second magnetic recording layers. The interlayer is deposited to a thickness of between 5-50 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.

Magnetic recording medium having a multilayer magnetic recording

An improvement in a magnetic recording medium having an underlayer and a magnetic layer is described. The improvement, effective to increase the coercivity of the medium, includes deposition of an interlayer between the underlayer and the magnetic recording layer. The interlayer is deposited to a thickness of between 10-60 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.

Magnetic recording medium having a CoCr alloy interlayer of a low

An improvement in a magnetic recording medium having an underlayer and a magnetic recording layer is described. The improvement, effective to reduce media anisotropy, includes deposition of a prelayer on the substrate, prior to deposition of the underlayer. The prelayer is deposited to a thickness of between 10-60 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.

Magnetic recording medium having a prelayer

A texturing device for texturing a disc substrate of the type used in forming a thin-film medium is described. The device includes a rotatable assembly having a first pad attached to one end of a spindle and an annular ring having a second pad attached on one surface. Each pad defines a texturing surface for texturing the inner and outer regions of the disc substrate.

Device for texturing a disc substrate

A target assembly for use in forming a protective overcoat in a magnetic recording medium is described. The assembly includes a centrally positioned target with inner and outer magnetic means adjacent the target. A sputtering shield is positioned between the target and the medium for controlling the amount and angle of material deposition on the medium. The assembly is effective to deposit an overcoat having a greater thickness in the inner landing zone of the medium than in the outer data zone. A method of using the assembly is also disclosed.

Target assembly for use in forming an overcoat in a magnetic recording

A method for forming an overcoat having first and second layers in a magnetic recording medium is described. The first overcoat layer is deposited in a first sputtering chamber where the magnetic means for confining target plasma in the chamber are oriented to retain magnetic-field confinement about the target surface and to produce magnetic field lines between directly confronting portions of the confronting sputtering targets. The second overcoat layer is deposited under a nitrogen-containing atmosphere.

Method for forming a thin carbon overcoat in a magnetic recording medium

A sputtering assembly for use in forming sputter deposited layers on a substrate is described. The assembly includes a pair of confronting sputtering targets for depositing sputtered layers onto the substrate and a movably mounted heating means for heating the substrate. A method of using the assembly is also disclosed.

Single chamber sputtering assembly

A cathode assembly having a magnetic-field shunt for use in a magnetron sputtering apparatus is described. The magnetic-field shunt disposed between a sputtering target and a source of magnetic flux, and the shunt is moveable between first and second positions to effect preferential target erosion at first and second target regions, respectively. A method of using the assembly for preparation of a magnetic recording medium is also described.

Cathode assembly having rotating magnetic-field shunt and method of

An improvement in a magnetic recording disc having a protective overcoat is described. The overcoat extends between an inner-diameter landing zone and a data zone and has a thickness in the landing zone of at least 135 .ANG. and a thickness in the data zone of less than 90 .ANG..

Magnetic recording disk with overcoat thickness gradient between a data

A target assembly for use in fabricating magnetic recording media is described. The target assembly has inner and outer concentric targets for sputter depositing on a substrate first and second layers having different compositions. Disposed adjacent each target is a magnetic means, and at least one which is reversible in magnetic-pole polarity. One polarity produces a magnetic flux sufficient to ignite a sputtering plasma in the inner target only, when power is supplied to the inner target at a preselected level. The opposite polarity produces a magnetic flux sufficient to ignite a sputtering plasma in the outer target only, when power is supplied to the outer target at a preselected level.

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Los Gatos, CA, United States of America

Michael A Russak