International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Eric James Lee

Edward Hin Pong Lee

Robert Fontana

Richard Hsiao

Ashok Lahiri

Hong Xu

Peter Beverley Powell Phipps

Hugo Alberto Emilio Santini

Amanda Baer

Thomas Carl Clarke

Francisco Agustin Martin

Florence Eschbach

Francisco Martin

Leping Li

Steven G Barbee

Hung-Chin Guthrie

Scott Arthur MacDonald

Frederick Hayes Dill

William L Guthrie

Cong Wei

Thomas Edward Dinan, Jr

Li-Chung Lee

Frederick Hayes Dill, Jr

A method for simultaneously planarizing to relatively equal smoothness a thin film magnetic head hardbaked resist structure having relatively low surface energy and one or more additional thin film magnetic head structures containing other materials having comparatively higher surface energy, such as copper, hardbaked resist, alumina and NiFe. The method begins with preparation of a chemical mechanical polishing (CMP) slurry targeted at equaling the removal rate of the materials to be planarized. The CMP slurry includes a liquid vehicle, an abrasive, and a surfactant. The CMP slurry is applied to the surface of the structures to be planarized and the structures are simultaneously planarized using a CMP planarization technique.

Simultaneous planarization of pole piece and coil materials for write head applications

A thin film magnetic head that includes an improved Ppole tip/yoke interface. The process for forming the Ppole tip/yoke interface includes a CMP polishing step that is performed on the surface of the wafer subsequent to the plating of the Ppole tip. This CMP step utilizes a relatively soft polishing pad and an acidic polishing slurry which preferentially attacks the Ppole tip material, such that the CMP step results in the recession of the upper surface of the Ppole tip relative to the dielectric layer surrounding it, as well as the significant rounding of the upper edges of the dielectric trench in which the Ppole tip is formed. Thereafter, when the yoke is plated onto the Ppole tip the rounded upper edges of the dielectric trench result in a concave curved interface between the yoke and the Ppole tip.

Method for shaping pole pieces of magnetic heads by chemical mechanical polishing

A process for forming the Ppole tip/yoke interface of a magnetic head that includes a second CMP polishing step that is performed on the surface of the write head wafer subsequent to the plating of the Ppole tip thereon, and subsequent to a first CMP step. This second CMP step utilizes a relatively soft polishing pad and an acidic polishing slurry which preferentially attacks the Ppole tip material. This results in the recession of the upper surface of the Ppole tip relative to the dielectric layer surrounding it, and significant rounding of the upper edges of the dielectric trench in which the Ppole tip is formed. Thereafter, when the yoke is plated onto the Ppole tip the rounded upper edges of the dielectric trench result in a concave curved interface between the yoke and the Ppole tip.

In a first aspect a slurry is provided for chemically mechanically polishing alumina and nickel iron to a common plane and in a second aspect a slurry is provided for additionally chemically mechanically polishing copper to a common plane. The slurry includes a first concentration of colloidal silica, a second concentration of potassium and/or sodium persulfate and a third concentration of ammonium persulfate. In the first aspect the first and second concentrations are tailored to chemically mechanically polish the alumina and the nickel iron at the same rate to a common plane and in the second aspect the slurry includes a third concentration of ammonium persulfate at a proper ratio to the potassium or sodium persulfate to chemically mechanically polish the copper at the same rate as the other materials to the same plane.

Slurry for multi-material chemical mechanical polishing

The thin film magnetic head of the present invention includes an improved P pole tip/yoke interface structure. The interface structure includes yoke material that is formed in a concave curved shape at the interface between the P pole tip and the yoke, such that a right angle interface between the P pole tip and the yoke is eliminated. The process for forming the P pole tip/yoke interface includes a second CMP polishing step that is performed on the surface of the write head wafer subsequent to the plating of the P pole tip thereon, and subsequent to a first CMP step. This second CMP step utilizes a relatively soft polishing pad and an acidic polishing slurry having a pH within the range of approximately 1 to approximately 5, and preferably approximately 2.5. The acidic polishing slurry contains a chemical agent which preferentially attacks the P pole tip material, such that the second CMP step results in the recession of the upper surface of the P pole tip relative to the dielectric layer surrounding it, as well as the significant rounding of the upper edges of the dielectric trench in which the P pole tip is formed. Thereafter, when the yoke is plated onto the P pole tip the rounded upper edges of the dielectric trench result in a concave curved interface between the yoke and the P pole tip. The resulting P pole tip/yoke interface possesses improved magnetic flux flow control properties and results in decreased side writing. Greater track per inch areal data storage results from the reduced side writing of the improved write head.

A magnetic head including a dual layer induction coil fabricated by reactive ion etching (RIE) techniques. An etch stop layer and an etchable insulation material layer and an induction coil etching mask are fabricated on a first magnetic pole. Induction coil trenches are thereafter RIE etched into the insulation material to the etch stop layer, and the first induction coil is fabricated into the induction coil trenches. Following a chemical mechanical polishing (CMP) step, a second etch stop layer, a second layer of etchable insulation material and a second induction coil etching mask are fabricated. Second induction coil trenches are RIE etched into the second insulation material layer to the second etch stop layer, and a second induction coil is fabricated into the second induction coil trenches. A second CMP step is followed by an insulation layer and the fabrication of a second magnetic pole (P ) upon the insulation layer.

Dual coil and lead connections fabricated by image transfer and selective etch

A read/write head is provided with an embedded planar dual coil write structure. The head includes generally parallel shield, shield/pole, and pole layers. The shield/pole layer abuts a generally coplanar planarization layer in one embodiment. A circuitous recess is defined in the shield/pole and planarization layer, spanning the junction twice and encircling a central hub of adjoining shield/pole and planarization layer material. A write structure is located in the recess, with the shield/pole layer, planarization layer, and embedded write structure forming a substantially flat surface for building the pole layer. The write structure includes first and second substantially co-planar multi-turn flat coils, where turns of the first write coil are interspersed with turns of the second write coil. The first and second write coils reside in the circuitous recess, winding around the central hub. An insulating material separates the first and second coils.

Embedded dual coil fabrication process

An apparatus and method of making is disclosed for a combination read/write head having improved topography. The disclosed read/write head combines a magnetoresistive (MR) read head with an inductive magnetic write head. The head is planarized at a second shield layer with a planarization layer such that pads and leads connecting the pads to the MR sensor and coil are on a planar surface of the planaritzation layer. This planarization layer allows first and second shield layers to be optimized for the MR sensor to be used and also separates the pads and leads from the substrate. The combination head has first and second shield layers formed on a substrate, the shield layers being separated by a read gap. A magnetoresistive (MR) sensor and MR leads are located in the read gap. The planarization layer is then formed on the substrate, surrounding the first and second shield layers creating a planar surface that is coplanar with a top surface of the second shield layer. A write gap layer is fabricated along with a pole piece. The pole piece being separated by the write gap layer at the ABS and connected to the second shield layer at a back gap that is recessed in the head from the ABS. An insulation layer and coil layer embedded in the insulation layer with the insulation layer and the coil layer being located between the second shield layer and the pole piece. Pads and leads are formed on the planarization layer, with the leads electrically connected to the MR sensor and the coil.

Combination inductive write head and magnetoresistive (MR) read head with improved topography

A method is described for fabricating a cloisonn&eacute; structure, in which a top surface of a metal oxide layer is made coplanar with a top surface of a metallic structure formed on a substrate. A nitride layer is deposited on at least the top surface of the metallic structure, and the metal oxide layer is deposited over the metallic structure and the nitride layer. The metal oxide layer is then polished by a chemical-mechanical polishing (CMP) process using a slurry, to expose the nitride layer on the top surface of the metallic structure. Polishing of the nitride layer causes ammonia to be generated in the slurry. The ammonia is extracted as a gas from the slurry, and a signal is generated in accordance with the ammonia concentration. The CMP process is terminated in accordance with a change in the signal. In a preferred embodiment, the metal oxide is aluminum oxide, the nitride is aluminum nitride, and the nitride layer is deposited as a conformal layer on the substrate and the metallic structure.

Endpoint detection in chemical-mechanical polishing of cloisonne structures

Embedded dual coil planar structure

A method planarizes a first pole piece layer of a write head by lapping without delaminating the first pole piece layer from an underlying second read gap layer on a wafer substrate. This is accomplished by separating or dicing the first pole piece material layer in a field region about rows and columns of first pole piece layers of magnetic head assemblies so as to reduce the stress of the first pole piece material layer in the field. Accordingly, when the wafer substrate is lapped, such as by chemical mechanical polishing (CMP), a reduced stress prevents the first pole piece material layer from delaminating from the second read gap layer during the lapping operation.

Growing community of inventors

San Jose, CA, United States of America

Eric James Lee