International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Richard Longstreth White

Bing K Yen

Jan-Ulrich Thiele

Daryl J Pocker

Cherngye Hwang

Charles Chung Lee

Kurt A Rubin

Bruno Jean Marchon

Qing Dai

Xiaoping Bian

Hong Deng

George William Tyndall, Iii

Jinliu Wang

Bond-Yen Ting

Eric Hwang

Michael Andrew Scarpulla

The present disclosure relates to a planarized bit-patterned magnetic medium that has a magnetic layer, including island regions and trench regions, a first carbon layer applied over the magnetic layer, and a second carbon layer applied over the first carbon layer, wherein the second carbon layer has been removed in the island regions. The first carbon layer may have a lower material removal rate when exposed to chemical-mechanical polishing than the second carbon layer. The present disclosure also relates to a method for planarizing a bit-patterned magnetic medium and a slurry composition for the chemical-mechanical polishing of carbon layers, the slurry composition including an oxidizer component, a catalyst component, a particulate component, and a reaction control component.

Composition and method for planarized bit-patterned magnetic media

A filament post used in plasma-enhanced chemical vapor deposition has an outer shell and an inner post. An electrical potential is applied only to the inner post to ensure that there is no impact on the plasma density and the carbon film properties. The inner post and the outer shell are electrically insulated by ceramic insulators, such that no electrical potential is applied to outer shell. The stress generated in the carbon film is directly related to the electrical potential of the surface to which the film is deposited. The carbon film deposited on the outer shell of the post is not highly stressed, which significantly reduces film delamination from the filament post surfaces.

System, method and apparatus for filament and support used in plasma-enhanced chemical vapor deposition for reducing carbon voids on media disks in disk drives

A method for measuring the thickness of a thin film disk overcoat layer includes radiating x-rays on a thin film disk comprising at least one base layer and an overcoat layer, collecting fluorescence data on electromagnetic radiation fluoresced from the thin film disk, reflecting polarized light from a surface of the thin film disk corresponding to the overcoat layer, collecting ellipsometry data from the polarized light, and estimating the thickness of the overcoat layer using both the fluorescence data and the ellipsometry data. The method may further include providing a statistical model to determine optimal deposition and manufacturing parameters. A system to conduct the described method may include a data analyzer, an ellipsometry measurement device, and an x-ray fluorescence measurement device.

Method and system for measuring overcoat layer thickness on a thin film disk

The fabrication of the overcoat layer starts with a low energy ion beam to avoid magnetic layer implantation problems, followed by higher deposition energies where the higher energy atoms are implanted into the previously formed lower energy overcoat layer, rather than the magnetic layer. The energy gradient ion beam deposition process therefore results in a thin overcoat layer that is denser than a comparable layer formed by low energy magnetron sputtering, and which overcoat layer provides good mechanical and corrosion protection to the magnetic layer, without degrading the magnetic properties of the magnetic layer.

Energy gradient ion beam deposition of carbon overcoats on rigid disk media for magnetic recordings

A method for sputtering a thin film protective layer with improved durability is disclosed. The method reduces kinetic energy of the ions of the overcoat material during the initial period of deposition to form a buffering interface which reduces the interpenetration of the atoms of the protective layer into the underlying film. In the method of the invention the sputtering of the overcoat preferably begins with zero (or very low) voltage applied to the underlying film resulting in minimal ion implantation in the underlying film. The 'high energy' phase of the process begins with increases in the magnitude of the negative bias voltage applied to the underlying film. The higher energy imparted to ions in the plasma result in a denser and harder film being formed over the initial buffer layer. The protective layer preferably comprises carbon and nitrogen.

Thin film protective layer with buffering interface

The fabrication of an overcoat layer starts with a low energy ion beam to avoid magnetic layer implantation problems, followed by higher deposition energies where the higher energy atoms are implanted into the previously formed lower energy overcoat layer, rather than the magnetic layer. The energy gradient ion beam deposition process therefore results in a thin overcoat layer that is denser than a comparable layer formed by low energy magnetron sputtering, and which overcoat layer provides good mechanical and corrosion protection to the magnetic layer.

A overcoat layer of TiSi N for use on a magnetic thin film disk is disclosed. The overcoat of the invention has high hardness, provides corrosion protection and has low surface energy which reduces contaminant attraction. The TiSi N film is conductive and, therefore, reduces the deleterious effects of tribocharging.

Thin film TiSixNy protective layer

A thin film structure comprising a protective layer structure having at least two different compositions of carbon and nitrogen with the surface of the protective layer having the lowest nitrogen content is disclosed. The protective layer structure of the invention is preferably used over the magnetic material in a thin film magnetic disk. In the protective layer structure of the invention, the durability of a relatively high nitrogen content CNx material is improved by the addition of a surface sublayer of CNx with a relatively low nitrogen concentration. The resulting protective layer structure provides superior durability to either of the thin film compositions used alone achieving a synergistic result. The protective layer structure of the invention has the additional benefit of decreasing the polar surface energy and therefore, improving the corrosion resistance of the film structure. In one embodiment the protective layer of the invention is implemented as two discrete sublayers with the surface sublayer having the lowest nitrogen concentration. In this embodiment the surface sublayer has from 0 to 8 at. % nitrogen and the higher nitrogen content is between 10 and 25 at. % nitrogen at the magnetic layer interface. The protective layer structure of the invention can also be implemented as a film in which the nitrogen content gradually decreases between the magnetic layer and the surface of the protective layer structure.

Magnetic thin film media with a protective layer of CNx having a plurality of compositions

Improved apparatus and methods for depositing thin films are described. A sputtering system according to the invention enhances the effects normally achieved with negative voltage bias by having two electrodes driven alternately as anode and cathode by a midfrequency power supply in combination with pulsing a negative bias voltage source for the substrate where the film is being deposited. The invention may be embodied in a multiple disk in-line sputtering system or a single disk sputtering system. Although the invention is potentially useful with any thin film which benefits from being deposited using bias, the described embodiment using the sputtering system according to the invention is for depositing an overcoat on a magnetic disk which is carbon based and includes hydrogen and/or nitrogen.

Method and apparatus for sputtering thin films

A thin film disk and a method for producing the disk having an overcoat with two thickness regions. The thicker overcoat region can be used as a start/stop or loading zone and the thinner overcoat region can be used over the data recording area. This provides increased wear resistance while allowing improved magnetic performance through a reduction in the thickness of the overcoat over the data recording area. The dual thickness regions can be formed using different embodiments of the method. One method sputter deposits a relatively thick layer of overcoat material over the entire disk surface, masks off the portion of the disk for the thick layer, etches the unmasked area to reduce or eliminate the overcoat from the unmasked area, then deposits a second relatively thin layer of overcoat material over the entire surface.

Thin film protective coating with two thickness regions

The embodiments of the invention are one, two or three layer protective hydrogenated carbon (C:H) thin film coatings on a disk with hydrogenation levels that are higher at the surface and decrease from the surface downward toward the substrate. The hydrogen content of the various layers or zones of the overcoat are optimized to use the varying properties of C:H films such as good adhesion obtained with a low level of hydrogen, the high hardness of an intermediate level of hydrogen content and the low surface energy of a high hydrogen content film. In one embodiment the disk is coated with a sputtered C:H thin film with a gradient in the hydrogen concentration, with the concentration increasing toward the film surface. A second embodiment of the invention uses two layers in which the hydrogen content of bottom layer is lower than the surface layer. A third embodiment of the invention uses a three layer construction of the thin-film having a minimum hydrogenation level in the bottom layer, an intermediate hydrogenation level in the middle layer and a high hydrogenation level in the top layer.

Growing community of inventors

Los Altos, CA, United States of America

Richard Longstreth White