International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Hugo Alberto Santini

Richard Hsiao

Robert Fontana

Neil Leslie Robertson

Clinton David Snyder

David Eugene Heim

Kochan Ju

Steven Robert Hetzler

Moris Musa Dovek

Cherngye Hwang

Mao-Min Chen

Tsann Lin

Mohamad Towfik Krounbi

Ching Hwa Tsang

Mason Lamar Williams

Virgil S Speriosu

Marc David Levenson

Rodney E Lee

Johannes Grandia

Hung-Liang Hu

Michael J Armstrong

William C Cain

Mason L Williams, Iii

Daniel Francis O'Kane

Harold L Turk

William G McChesney

David P Wick

A magnetic transducer with a bilayer pole piece in which a first layer of material forms the body of the pole piece and a second layer forms the pole tip after milling is disclosed, along with a disk drive using the transducer. The bilayer pole piece is used in a method to improve the determination of the optimum stopping point for the ion milling using the optically observable process of the gap layer and P tip layer being milled off of the P protection layer forming a gradually disappearing halo. The process of making the head proceeds conventionally through plating of the P layer which in applicant's head is the layer which forms the body of P . The process of the invention deposits a P protection layer and then uses a photo lift-off technique to form a void in the P protection layer where the gap and the P and P tips will be formed, i.e., the zero throat region. An additional ferromagnetic layer (the &ldquo;P tip layer&rdquo;) is vacuum deposited in the void area to a thickness equal to the final desired pole tip height. The gap layer is deposited and the P tip is formed as in the prior art. Ion milling using the P tip as a mask is then performed as in the prior art with the exceptions: 1) that the P protection layer protects areas of the wafer which should not be milled; and 2) instead of milling a notch in the planar surface of P , only the excess of the P tip layer is required to be milled.

Magnetic transducer with bilayer pole piece structure with improved milling endpoint detection

A method for forming metrology structures on a wafer on which magnetic transducers are being fabricated is disclosed. The metrology structures have a measurable electrical resistance which is an accurate surrogate for a physical dimension of a structure of the magnetic transducer, such as a pole piece tip. The metrology structure is preferably a resistor with pads usable with a four point probe. The resistor is preferably formed by creating a sacrificial pole piece structure over a pad of resistive material. The narrow dimension of the pole tip is then used as a mask to replicate the width of the pole tip in the resistive material through a milling process which removes resistive material outside of the masked area of the resistor pad. Control structures with unmilled pads of resistive material are formed along with the metrology structures to provide the sheet resistance of the pads prior to milling. Knowledge of the sheet resistance allows the resistance of the milled structure to be converted into an accurate measure of the physical dimension of the pole piece tip.

Method for measuring fine structure dimensions during manufacturing of magnetic transducers

An MR read head has first and second lead layers protected by first, second and third insulation layers in addition to the first and second insulative gap layers substantially all the way from the side edges of an MR sensor to terminals. The first and second insulation layers do not extend outside of the first and second lead layer sites so that greater heat dissipation can be realized from the MR sensor. Each lead layer comprises first and second lead layer films. Where these films overlap for electrical connection their top and bottom surfaces are protected by the first and second insulation layers and their edges are protected by the third insulation layer. Where the first lead layer film extends from the second lead layer film toward the respective terminal its bottom surface is protected by the first insulation layer and its top surface and its side edges are protected by the third insulation layer. Only three masks are required for fabricating or constructing these components. The first liftoff mask is employed for defining the first insulation layer and the first lead layer film. The second liftoff mask is employed for depositing the second lead layer film on the first lead layer film with an end of the second lead layer film for defining the track width of the MR sensor and making a contiguous junction with a respective side edge of the MR sensor and then depositing a second insulation layer on the second lead layer film. A third liftoff mask is employed for masking the MR sensor site and the second lead layer film of the first and second lead layers so that the height of the MR sensor can be defined and the third insulation layer deposited.

Method of making a high resolution lead to shield short-resistant read

A combined sunken magnetoresistive (MR) read/write head is provided wherein first and second shield layers are eliminated or thinned down in an insulation stack region just behind a pole tip region. This provides a depression behind the pole tip region where head components, such as the write coil, insulation stack and pole pieces of a write head, are located. Leads for an MR sensor of the head extend parallel to an air bearing surface (ABS) where they connect to first and second conductors beyond the limits of the shield layers. The conductors extend back into the head normal to the air bearing surface without any danger of shorting to the shield layers.

Method of making read/write magnetoresistive (MR) head with sunken

The present invention provides a merged magnetic head and method of making wherein a write portion of the magnetic head is constructed before the read head portion and the first pole tip of the write head defines the track width and zero throat height of the magnetic head. During construction, each insulation layer of an insulation stack is planarized with components of a partially completed first pole piece, thereby promoting highly effective construction of one or more coil layers and the first pole tip of the write head. The insulation stack is recessed with respect to the top surface of the first pole tip so that the insulation stack has substantially no impact on photoresist patterning of the first pole tip. Insulation layers of the stack extend into the field beyond side edges of the first pole piece layer so as to provide planar support for the one or more coil layers. The second pole piece/first shield layer is constructed on a flat surface followed by a first read gap layer, read sensor, first and second lead layers, a second read gap layer and a second shield layer, which are all planar. The lowering of the insulation stack with respect to the top surface of the first pole tip causes the write gap to be closer to the read gap so as to minimize misregistration of the read and write heads when they are located over an outer track on a magnetic disk.

Write head before read head constructed merged magnetic head with track

A method makes a magnetic write head with a plated self-aligned zero throat height (ZTH) defining layer without reflective notching. In the method a seedlayer is deposited on a first pole piece layer, a negative resist layer is photopatterned on the seedlayer with a first opening that frames a location for a second pole piece, a positive resist layer is photopatterned on the negative resist layer with a second opening that frames a location for the ZTH defining layer, the ZTH defining layer is plated, the positive resist is removed, the second pole piece is plated and the negative resist is removed. The ZTH defining layer has a front vertical edge that is substantially parallel to an air bearing surface (ABS) and that is recessed from the ABS for defining the ZTH of the head.

Method of making a magnetic write head with plated self-aligned zero

An inductive magnetic head is provided which has a zero throat height (ZTH) defining insulation layer that is located entirely between the air bearing surface (ABS) and a coil layer of the head. The ZTH defining insulation layer has a front end which defines the zero throat height (ZTH) of the head. An insulation stack, with one or more coil layers embedded therein, is located between the ZTH defining insulation layer and a back gap where first and second pole pieces are connected. The insulation stack has a first insulation layer that has a thickness that is less than the thickness of the ZTH defining insulation layer so that the final stack has less height than previous insulation stacks. The lower stack permits the construction of a second pole piece pole tip portion with improved side wall definition. This is due to the fact that the photoresist layer used for frame plating the second pole piece will have less thickness in the pole tip region allowing improved light patterning penetration and a better resist frame prior to plating the second pole piece.

Inductive head with reduced height insulation stack due to partial

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

A combined read head and write head includes at least one write coil layer embedded in an insulation stack. The insulation stack is sandwiched between first and second pole piece layers that are connected at a back gap. The pole piece layers have first and second pole tips that have edges that form a portion of an air bearing surface. A write gap layer that forms a portion of the air bearing surface is sandwiched between a top surface of the first pole tip and a bottom surface of the second pole tip. A non-magnetic electrically conductive layer on top of the second pole tip forms a portion of the air bearing surface. A magnetoresistive sensor is sandwiched between first and second gap layers, which are sandwiched between first and second shield layers. The second shield layer is a common layer with the first pole piece layer.

Combined read head and write head with non-magnetic electrically

Combined magnetoresistive (MR) read and inductive write head with sunken

High resolution lead to shield short-resistant read head

The present invention uncouples the dependence between the zero throat height and the flare point of a write head by recessing the first insulation layer within the first pole piece layer. The first pole piece layer and the first insulation layer have planar surfaces which preferably lie in a common plane, the zero throat height being defined at the point where the planar surface of the first pole piece layer first meets the planar surface of the first insulation layer within the head. It is also at this point that the first and second pole piece layers separate from one another. Accordingly, the zero throat height can be accurately placed relative to the stripe height of a magneto-resistive (MR) sensor. Further, when a photoresist layer is spun onto the partially completed head for the construction of the pole tip of the second pole piece light directed into the photoresist layer for photo-imaging the pole tip does not reflect into the photoresist layer adjacent the pole tip. Accordingly, there is substantially no reflective notching of the photoresist layer because of the flatness of the surfaces of the first pole piece layer and the first insulation layer thereby permitting construction of a well defined second pole tip.

Method of making thin film induction recording head having an inset

The back end of an MR sensor and a flux guide are joined by a contiguous self-aligned junction so that a predictable overlap of the flux guide on the back end of the MR sensor can be achieved for optimizing signal flux density in the MR sensor. Lead/longitudinal bias layers for the MR sensor are also joined by a contiguous self-aligned junction to the flux guide for stabilizing the flux guide. By employing a single lift off resist mask the MR sensor and the lead/longitudinal bias layers can be patterned followed by deposition of the flux guide. The flux guide is a bilayer of an insulation material layer and a flux guide material layer. The insulation material layer is sandwiched between the MR sensor and the flux guide material layer and between the lead/longitudinal bias layers and the flux guide material layer. A heat guide or combined flux guide and heat guide may be substituted for the aforementioned flux guide.

Stabilized MR sensor and flux guide joined by contiguous junction

A method for making a merged thin film read/write head, where the first pole piece includes a pedestal or pole tip portion that extends up from the first pole piece layer, uses electroplating to form the gap so that the gap layer does not have to be removed later. After the first pole piece is deposited, the coil insulation structure is built over the first pole piece. Afterwards an electrically conductive seed layer of the same ferromagnetic material as the first pole piece is formed over the wafer to provide an electrically conductive path for subsequent electroplating. After the seed layer deposition, a photoresist pattern is then formed to define the shape of the second pole piece. Nonmagnetic nickel-phosphorous is then electroplated onto the seed layer in the region not covered by the photoresist pattern to form the gap layer. The second ferromagnetic layer is then electroplated onto the gap layer to define the shape of the second pole piece. The thickness of the second pole piece layer is deliberately made thicker than the desired final thickness because the second pole piece layer is used as a mask for subsequent ion beam milling to form the notched pole tip element of the first pole piece. The photoresist is removed and ion beam milling performed to remove the seed layer and a portion of the first pole piece layer to define the pedestal pole tip element of the first pole piece. The ion beam milling does not have to remove the gap layer because the electroplated gap has been defined by the photoresist pattern to have the desired trackwidth.

Method for making a thin film inductive write head having a pedestal

A method is disclosed for fabricating a high density recording head having a narrow, well-defined second pole tip for recording data with an areal density in the range of 5 gigabits. The second pole tip is connected to a mushroom yoke which extends across underlying insulated coils. The second pole tip and yoke are formed at the same time using conventional photolithographic and plating processes. By using a preselected thickness for the photoresist mask layer over the head body region, an aspect ratio for the photolithographic process of less than 4:1 is achieved in the head pole tip region. However, the thickness of the photoresist mask layer in the head body/yoke region will be less than the desired thickness of the second pole piece, which creates a problem of a void beneath mushroomed overhanging edges. By back-filling the void with an insulating material at the time the head is sealed, the void problem is overcome.

Growing community of inventors

San Jose, CA, United States of America

Hugo Alberto Santini