International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Timothy Martin Reith

Brian Rodrick York

Ernesto Esteban Marinero

Tim Minvielle

David Thomas Margulies

Hoa Van Do

James Aloysius Hagan

Michael J Sullivan

Hal Jerves Rosen

James F White

Xiaoping Bian

Mary Frances Doerner

Mohammad Taghi Mirzamaani

Thomas A Gregory

John C Cheng

Robert Waltman

John James Gniewek

Owen R Melroy

James S Wong

Peter Paul Peressini

Nancy J Jubb

A method of influencing variations in composition of thin films is described. The elemental plasma field distribution in sputtering systems is manipulated by generating a nonuniform electric field along a surface of the substrate to alter the composition by differentially re-sputtering the target elements. The nonuniform electric field is used to modulate the kinetic energy of the ions generated in the plasma which strike the thin film's surface. By applying varying electric potentials at a plurality of points on a conductive surface of a substrate, the electric field across the surface of the substrate can be modulated in a variety of patterns. In the preferred embodiment a radial voltage gradient is applied to a conductive surface of a disk on which a magnetic thin film is being formed to radially modulate the platinum content of the magnetic film.

Magnetic thin film disks with a nonuniform composition

This invention provides a disk which has an in-plane oriented magnetic recording layer on a glass, ceramic, or other nonmetal substrate and a method for making the disc. A thin layer of texturable NiP is sputtered on the substrate. This NiP layer is textured before the magnetic layer is deposited. The disk combines all the advantages of a glass or ceramic substrate along with the advantages of an oriented magnetic medium.

Oriented magnetic recording media on a nonmetallic substrate

A method of influencing variations in composition of thin films is described. The elemental plasma field distribution in sputtering systems is manipulated by generating a nonuniform electric field along a surface of the substrate to alter the composition by differentially re-sputtering the target elements. The nonuniform electric field is applied by one or more electrodes in contact with a conductive surface or by using an RF bias signal. The nonuniform electric field is used to modulate the kinetic energy of the ions generated in the plasma which strike the thin film's surface. Since the kinetic energy and the mass of the sputtering gas ions and neutrals affect the re-sputtering rate, the nonuniform electric field differentially affects the elements being deposited according to mass. By applying varying electric potentials at a plurality of points on a conductive surface of a substrate, the electric field across the surface of the substrate can be modulated in a variety of patterns. For example, the field can be varied along the circumferential and/or radial direction of a disk. In the preferred embodiment a radial voltage gradient is applied to a conductive surface of a disk on which a magnetic thin film is being formed to radially modulate the platinum content of the magnetic film. Modulating the radial platinum content in turn modulates the radial coercivity.

A lubricating perfluoropolyether (PFPE) composition for lubricating one or more disks in a disk drive system may be formed by providing a first component of PFPE molecules having an aggregate vapor pressure in the range of 1&times;10 to 1&times;10 atm and a second component of PFPE molecules comprising at least 5% of the total number of molecules of the first component, wherein the second component includes an aggregate vapor pressure lower than that of the first component. The first and second components are mixed together to form a homogeneous composition, which may be in the liquid form. The composition may be introduced into a reservoir in a vapor phase lubricant reservoir system in a disk drive enclosure.

Disk drive lubricant reservoir systems and lubricants used therein

This invention provides a disk which has an in-plane oriented magnetic recording layer on a glass, ceramic, or other nonmetallic substrate and a method for making the disk. A thin layer of material is deposited on the substrate to form a texture stop layer. A texturable layer is then deposited on the texture stop layer. This texturable layer is textured before the magnetic layer is deposited. The disk combines all the advantages of a glass or ceramic substrate along with the advantages of an oriented magnetic medium.

Oriented magnetic medium on a nonmetallic substrate

A improved thin film recording medium with an underlayer with deliberately induced strain, crystalline defects and dislocations (collectively &ldquo;faults&rdquo;) in the grain structure is described. The relatively high number of induced faults results in surprising improvements in recording characteristics such as soft error rate, resolution and SNR of the thin film disk. While the film is being deposited, the sputtering conditions are controlled to grow grains of the underlayer material which tend to be highly faulted by incorporation of atoms of a second material with significantly different atomic characteristics than the underlayer material. Preferably the atoms of the sputtering gas species are incorporated in the film to cause the lattice faults. For example, the faults can be achieved by incorporating sputtering gas atoms, e.g. argon atoms, into a chromium based underlayer.

Thin film disk with highly faulted crystalline underlayer

A thin film magnetic disk (and a disk drive using the magnetic disk) with improved recording performance having a thin seed layer consisting of tantalum (Ta), a suitable underlayer and a CoPtCrB magnetic layer is described. The underlayer is preferably a Cr alloy with a grain size which is smaller than that of pure Cr. CrTi is suitable as an underlayer. An appropriate overcoat such as hydrogenated carbon can be applied.

Thin film magnetic disk with CoPtCrB layer

A thin film disk and a disk drive using the thin film disk are described. The disk has a thin film magnetic layer composed of small acicular grains having an average aspect ratio greater than one which results in improved recording performance. The development of the acicularity is aided through the crystal structure having anisotropic inplane stress with a radial stress being less than a tangential stress. The preferred magnetic material is an alloy cobalt which includes a glass forming material such as boron, boron oxide, silicon, silicon oxide, carbon, phosphorus, etc. The typical hcp unit cells form acicular grains with a tendency for the C-axis to be orthogonal to a long axis of the acicular grains. Preferably the C-axis of the grains is oriented along the circumferential direction of the disk. Preferably the underlayer is sputtered deposited using negative bias.

Thin film disk with acicular magnetic grains

A method of manufacturing a photomask for the production of dual depth features on substrates, and the photomask so manufactured, wherein the method of manufacturing the photomask is comprised of the steps of: (1) coating a substrate which transmits at least two selected wavelengths with: a) an optical filter material which prevents the transmission of at least one of the wavelengths, b) an opaque masking material, and c) a dual tone photoresist; (2) using a single mastering tool to selectively expose areas of the coated substrate to one of the wavelengths; (3) developing the photoresist; (4) etching the exposed masking material and optical filter material; (5) exposing the remaining coated substrate; (6) developing the remaining photoresist; (7) etching the exposed surface; and (8) stripping away the remaining photoresist.

Dichromatic photomask and a method for its fabrication

An improved thin magnetic layer which is suitable for use in magnetic head pole piece applications and a method of manufacture therefor are disclosed. The magnetic layer is a single phase composition of NiFe and Al.sub.2 O.sub.3. The magnetic layer is manufactured by cosputtering from a single, two phase sputtering target, or from separate NiFe and Al.sub.2 O.sub.3 sputtering targets. The single phase composition results in increased abrasion resistance without degradation of the magnetic properties of the layer.

Magnetic layer and method of manufacture

Use of a rare gas in combination with oxygen or nitrogen to sputter etch unreacted platinum after formation of a platinum silicide contact structure for the formation of a Schottky Barrier diode in a silicon semiconductor substrate.

Method for forming Pt-Si Schottky barrier contact

The method allows the formation of a self-aligned guardring surrounding a Schottky barrier device. The resulting guardring is as close to the Schottky barrier device as is possible. This reduces the area of the chip used by other guardring forming techniques of the prior art. The method involves first opening a hole in an insulator to expose the silicon surface. The Schottky barrier forming metal is then deposited over the insulator and the silicon surface. Heat treatment of the appropriate temperature and time is utilized to form the metal silicide Schottky barrier device. During this device formation, there is a volume shrinkage in the metal silicide which forms a narrow annulus of exposed silicon around the metal silicide contact. The unreacted metal is removed. Ion implantation of ion of opposite polarity to the exposed silicon is imparted to the structure to form a guardring surrounding the Schottky barrier device.

Growing community of inventors

San Jose, CA, United States of America

Timothy Martin Reith