International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Clinton David Snyder

Richard Hsiao

Hugo Alberto Santini

Michael Anthony Moser

Robert Fontana

Hong Xu

Alfred Grill

Cherngye Hwang

Neil Leslie Robertson

Ashok Lahiri

Vishnubhai Vitthalbhai Patel

Oscar Jaime Ruiz

Howard Gordon Zolla

James Bernard Kruger

Thomas Edward Dinan, Jr

James William Berberich

John I Kim

Archibald C Munce, Jr

Celia E Yeack-Scranton, Deceased

C E Yeack-Scranton, Deceased

Erhard Theodor Schreck

Mike Suk

Timothy C Reiley

Randall George Simmons

Harbans S Sachdev

Amanda Baer

Wai Cheung Leung

John Martin Burns

Celia E Yeack-Scranton

Barbara D Grant

Walter Crooks

Paul L Gendler

Vlad J Novotny

Richard D Balanson

Genevieve M Adams

Leo J Kadehjian

The present invention includes an overplated component which includes an enlarged mushroom head having outer portions which overhang a hard baked resist layer. The device is ultimately encapsulated such that no voids and/or redeposition problems exist under the overhang due to the presence of the hard baked resist. While not intended to be limiting in any manner, a device of the present invention is a thin film magnetic head wherein the yoke portion of a magnetic pole is formed utilizing the mushroom plating techniques of the present invention. Another mushroom plated component found in many devices is a mushroom plated electrical interconnecting stud that is formed utilizing the process steps of the present invention.

Self-aligned void filling for mushroomed plating

An isotropic deposition method for trench narrowing of thin film magnetic write head features to be created by reactive ion etching. According to the method, a photolithographically defined photoresist trench is formed over a hardmask and underlying polymer layer as part of tri-layer resist process. Instead of performing the usual hardmask and polymer etching steps using the photoresist mask pattern, a spacer layer is deposited isotropically or directionally at an angle to cover the vertical side walls of the trench. The spacer layer is etchable by the hardmask etch process but resistant to the polymer etch process. When the hardmask etch process is performed, the spacer layer material applied to the trench side walls remains intact, thereby defining a narrowed trench that is extended by the subsequent base layer etch process.

Isotropic deposition for trench narrowing of features to be created by reactive ion etch processing

A method of manufacturing includes 2 mushroom plating process starts with an overplated component which includes an enlarged mushroom head having outer portions which overhang a resist layer. The next step in the first process embodiment is a heating step in which the resist layer is hard baked. Thereafter, using a dry etch process, such as a reactive ion etch (RIE) process, the hard baked resist layer is removed in all areas except beneath the overhang of the mushroom head. The area beneath the overhang thereby remains filled with hard baked resist. Thereafter, the device is ultimately encapsulated such that no voids and/or redeposition problems exist under the overhang due to the presence of the hard baked resist. In an alternative process embodiment of the present invention the dry etch process is conducted first upon the resist layer, such that the resist layer is removed in all areas except under the overhang. Thereafter, the device is baked, such that hard baked resist remains beneath the overhang. Ultimately, the device is encapsulated and no voids or redeposition problems exist beneath the overhang due to the presence of the hard baked resist.

A fabrication method using a bottom anti-reflective coating (BARC) eliminating deleterious effects of unwanted reflected light during the photo exposure step of a photolithographic process. The BARC coating comprises a carbon coating having a thickness of 300 angstroms, deposited by a carbon ion beam deposition tool, and an initial silicon BARC coating layer having thickness of 20 angstroms deposited before the carbon coating. Where the BARC layer is utilized in a photolithographic NiFe pole tip fabrication process, a NiFe seed layer is first deposited upon a substrate. The BARC layer is then formed on the NiFe seed layer and the pole tip trench is then photolithographically created. Thereafter, the BARC layer is removed from the bottom of the trench, utilizing a reactive ion etch process, exposing the NiFe seed layer. The NiFe pole tip is then fabricated into the trench, and any remaining photoresist and BARC layer are removed.

Use of thin carbon films as a bottom anti-reflective coating in manufacturing magnetic heads

A thin film inductive write head has minimal organic insulation material in contact with the encapsulating overcoat. The process for its fabrication includes a reactive ion etching (RIE) process to remove the organic insulative material while still allowing the head top pole piece to be planar. The organic insulation material is removed by RIE down to the head gap layer in the region between the ABS and the coil. The etching is done with the top or second pole piece acting as a mask so that the planarized organic insulation material is still maintained over the portion of the coil that is located between the two pole pieces. Thus the organic insulation material is still present in this region as the planarization layer onto which the ferromagnetic layer for the second pole piece was deposited. This allows the encapsulating overcoat to be deposited directly on the gap layer, which is formed of the same material as the overcoat, rather than on the organic insulation material, in a substantial portion of the write head structure. In a further embodiment the write head also has the organic insulation material removed down to the gap layer between the coil turns in the portion of the coil that does not lie beneath the second pole piece. The region between the coil turns in this portion of the coil is filled with overcoat material during the head encapsulation process.

Thin film inductive write head with minimal organic insulation material

The present invention provides a prebent ceramic suspension which includes a ceramic load beam which is bent by a stress patch. With thin film techniques the stress patch is formed on top of the load beam. In the preferred embodiment the patch is amorphous hydrogenated diamond-like carbon. When the suspension is on a wafer the carbon patch exerts a compressive stress on a top surface of the load beam just under the patch. When the suspension is released from the wafer the compressive patch exerts tensile forces on the top surface of the load beam causing an end of the load beam to bend toward the wafer. The amount of bending of the suspension can be accurately controlled by the cross sections of the load beam and the patch as well as the lateral dimensions of the patch. Further control can be achieved by controlling the hydrogen, nitrogen and other additive components of the carbon patch. After fabrication bending can be lessened by machining portions of the patch with a laser beam to effectively negate the stress of these portions. Still further, the patch can be laterally configured so that the suspension forms an arc when preloaded on a disk During fabrication various layers can be formed by thin film deposition to form an integrated magnetic head-slider-suspension. A pair of prebent ceramic suspensions can be preloaded on adjacent magnetic disks by a single actuator arm.

Suspension bent by stressed patch

The present invention provides a prebent ceramic suspension which includes a ceramic load beam which is bent by a stress patch. With thin film techniques the stress patch is formed on top of the load beam. In the preferred embodiment the patch is amorphous hydrogenated diamond-like carbon. When the suspension is on a wafer the carbon patch exerts a compressive stress on a top surface of the load beam just under the patch. When the suspension is released from the wafer the compressive patch exerts tensile forces on the top surface of the load beam causing an end of the load beam to bend toward the wafer. The amount of bending of the suspension can be accurately controlled by the cross sections of the load beam and the patch as well as the lateral dimensions of the patch. Further control can be achieved by controlling the hydrogen, nitrogen and other additive components of the carbon patch. After fabrication bending can be lessened by machining portions of the patch with a laser beam to effectively negate the stress of these portions. Still further, the patch can be laterally configured so that the suspension forms an arc when preloaded on a disk. During fabrication various layers can be formed by thin film deposition to form an integrated magnetic head-slider-suspension. A pair of prebent ceramic suspensions can be preloaded on adjacent magnetic disks by a single actuator arm.

Ceramic suspension bent by stressed patch

A method for providing a thin film metallization area on a substrate is disclosed comprising the steps of: depositing a Ta adhesion layer on the surface of the substrate seed layer, conducting a photo resist process on the Ta adhesion layer to define the thin film metallization area, including a remnant removal process to remove remnant photo resist process material in the thin film metallization area to the Ta adhesion layer, the Ta adhesion layer preventing the remnant removal from reaching the seed layer, conducting a Ta removal reactive-ion-etch process to remove the Ta adhesion layer in the thin film metallization area, so that the seed layer is exposed in the metallization area. A metal material may then be deposited in the metallization area.

Tantalum adhesion layer and reactive-ion-etch process for providing a

A wear indicator is incorporated on the slider of a magnetic transducer in a magnetic storage system for in operation on-the-fly detection of the state of wear of the transducer. The wear indicator involves monitoring a change in an electrical property of an electrical circuit structure as the transducer is worn by abrasion against the magnetic disk medium. In one aspect of the present invention, the resistance (or conductance) of the circuit is monitored during disk drive operations. Part of the resistance (conductance) circuit structure is mounted on the slider and it is physically worn along with the wearing of the transducer. A predetermined change in resistance (or conductance) gives an indication of the predetermined wear limit at which the transducer should be replaced prior to its actual failure. In a specific embodiment, the circuit is configured such that an open circuit (infinite resistance or zero conductance) indicates that the wear limit has been reached. In another aspect of the present invention, the capacitance between a probe mounted on the slider and the magnetic disk is monitored during disk drive operations. The capacitance of the circuit changes as the transducer wears. A predetermined change in the capacitance give an indication of the wear limit at which the transducer should be replaced prior to its complete failure.

Magnetic transducer with wear indicator in a magnetic data storage system

A method is provided for making an assembly that has an integrated suspension, actuator arm and actuator coil. At least one actuator coil layer is located in the actuator arm region. The actuator coil layer is mounted to at least one homogeneous support layer which extends between terminal ends of the assembly for supporting all layers. A hole is provided through all layers in the actuator region at a pivot point for receiving an actuator spindle. In some embodiments of the invention, a transducer coil layer may be integrated in the suspension region and may be located in substantially a common plane with the actuator coil layer. The actuator region may be provided with a silicon base which contains integrated processing circuits which are connected to the transducer coil layer. A device may be carried by the assembly for bending the suspension region with respect to the actuator arm region. A method is provided for fabricating multiple integrated assemblies substantially entirely at the wafer level, each integrated assembly having a longitudinal recording magnetic head which has a close tolerance gap.

Method of making an integrated suspension, actuator arm and coil assembly

A contact recording disk file uses an integrated head-suspension assembly having a head carrier with a dual-layer wear pad for contacting the disk during read and write operations. The outer wear layer of the pad is relatively soft and wear prone compared to a harder and more wear-resistant inner layer. The outer wear layer wears away at a relatively rapid rate during initial wear-in of the head carrier. In this manner the head pole pieces, which extend into the wear pad, are rapidly put into contact with the disk, thereby compensating for initial misalignment of the wear pad with the surface of the disk. The inner wear layer then provides wear resistance over the life of the disk file. In the preferred embodiment, both the outer and inner wear layers are formed of essentially amorphous carbon doped with different amounts of hydrogen.

Contact magnetic recording disk file with improved head assembly

A method is provided for constructing well defined plated miniature metallic structures. A seedlayer may be formed over an insulative layer such as a gap layer of a write head. A protective layer, such as alumina or silicon dioxide, is formed on top of the seedlayer to protect it from a subsequent reactive ion etching (RIE) step. A relatively thick layer of material, such as polymeric photoresist, is formed on top of the protective layer, the thick layer being of a type of material which can be patterned by reactive ion etching. By photolithography, an RIE mask, such as a thin layer of patterned metal, is formed on top of the relatively thick resist layer. The pattern of the mask corresponds to the desired shape of the metallic structure to be formed by plating. After masking the relatively thick layer the relatively thick layer is anisotropically etched by RIE. After the thick layer is RIE'd the protective layer on top of the seedlayer portion to be plated is removed by an etchant such as an aqueous alkaline etchant containing EDTA. It is important that the polymeric photoresist not be attacked by this etchant since it would undercut the high definition required for the metallic structure. After the protective layer portion is removed electrodeposition takes place to plate the desired metallic structure on the seedlayer portion. After plating the remaining relatively thick layer can be removed by reactive ion etching and the remaining protective layer can be removed by the aforementioned etchant containing EDTA to leave the desired freestanding metallic structure with miniature high resolution features.

RIE image transfer process for plating

In the manufacture of a thin-film magnetic head having a vertical gap, auxiliary support is provided at the ends of a gap wall prior to formation of the magnetic poles. In a preferred embodiment, a pit is defined in a substrate and a release layer is deposited on the substrate followed by a layer of alumina. A recess is then etched through the alumina layer to the release layer in the pit. A partial layer of polymer or metal is deposited with a vertical edge across the median of the pit and recess. A layer of nonmagnetic wall material such as silicon oxide is deposited which after etching leaves a wall against the vertical edge of the partial layer. After removal of the partial layer, a vertical wall extends transversely across the recess and pit with the ends of the wall anchored and supported at the recess sidewalls. Alternatively, a pedestal may be provided in the recess to support each end of the wall. The magnetic poles are then formed simultaneously on either side of the wall. Other thin film layers are then deposited in an appropriate sequence of steps to complete the desired vertical gap, horizontal head structure. The substrate is separated from the completed thin film structure by dissolving the release layers.

Process for forming vertical gap in a thin film magnetic transducer

An assembly is provided which has integrated suspension and actuator arm regions. At least one actuator coil layer is located in the actuator arm region. The actuator coil layer is mounted to at least one homogeneous support layer which extends between terminal ends of the assembly for supporting all layers. A hole is provided through all layers in the actuator region at a pivot point for receiving an actuator spindle. In some embodiments of the invention, a transducer coil layer may be integrated in the suspension region and may be located in substantially a common plane with the actuator coil layer. The actuator region may be provided with a silicon base which contains integrated processing circuits which are connected to the transducer coil layer. A device may be carried by the assembly for bending the suspension region with respect to the actuator arm region. A method is provided for fabricating multiple integrated assemblies substantially entirely at the wafer level, each integrated assembly having a longitudinal recording magnetic head which has a close tolerance gap.

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Los Gatos, CA, United States of America

Clinton David Snyder