Abstract: A method for manufacturing a magnetic write head having a leading magnetic shield and a trailing magnetic shield that are arranged to prevent the lost of magnetic write field to the trailing magnetic shield. The write head includes a non-magnetic step layer that provides additional spacing between the trailing magnetic shield and the write pole at a region removed from the air bearing surface.

Abstract: A method and system for providing a PMR pole in a transducer including an intermediate layer are disclosed. A mask including line(s) having side(s) is provided. A hard mask is provided on the mask. Portions of the hard mask reside on the line side(s) and intermediate layer surface. The hard mask includes a wet-etchable layer and a high removal ratio layer on the wet-etchable layer. Part of the hard mask on the side(s) of the line is removed, exposing part of the line. The high removal ratio layer has a low angle removal rate on the line side(s) and a high angle removal rate on the intermediate layer surface. The low angle removal rate is at least four times the high angle removal rate. The line is removed, providing an aperture in the hard mask. A trench is provided in the intermediate layer. A PMR pole is provided.

Abstract: A magnetic writer comprises a write pole, a substrate and a non-magnetic, oxygen-free buffer material. The write pole has a leading edge, a trailing edge, a first side and second side. The substrate is at the leading edge of the write pole. The non-magnetic, oxygen-free buffer material is located between the write pole and the substrate.

Abstract: The method of the present invention provides a magnetoresistance effect element, which is capable of having a high MR ratio, corresponding to high density recording and being suitably applied to a magnetoresistance device even though a barrier layer is thinned to reduce resistance of the magnetoresistance effect element. The method of producing the magnetoresistance effect element, which includes the barrier layer composed of an oxidized metal, a first magnetic layer contacting one of surfaces of the barrier layer and a second magnetic layer contacting the other surface thereof, comprises the steps of: laminating the barrier layer on the first magnetic layer with using a target composed of the oxidized metal; and laminating the second magnetic layer on the barrier layer. The barrier layer is annealed before laminating the second magnetic layer thereon.

Abstract: A method for providing a structure in a magnetic transducer is described. The method includes performing a first planarization that exposes a top surface of the magnetic transducer. This first planarization also terminates before a portion of a first planarization buffer layer is removed. The method also includes providing a second planarization buffer layer after the first planarization is performed. The second planarization buffer layer is above the first planarization buffer layer. The method also includes performing a second planarization. This second planarization does not completely remove the second planarization buffer layer. The method also includes performing a third planarization terminating after the first planarization buffer layer is exposed and before the first planarization buffer layer is completely removed.

Abstract: A method in one embodiment includes forming a resist structure above an upper surface of a substrate, wherein a portion of the upper surface of the substrate is a shaping layer, wherein the resist structure has an undercut; depositing a layer of magnetic material above exposed regions of the substrate, wherein a portion of the layer of magnetic material tapers towards the substrate as it approaches the undercut; removing the resist structure; and forming a write pole above the layer of magnetic material. Additional methods are disclosed.

Abstract: A process for manufacturing a high performance MTJ it is described: A first cap layer of NiFeHf is deposited on the free layer, followed by a second cap layer of Ru on Ta. The device is then heated so that oxygen trapped in the free layer diffuses into the NiFeHf layer, thereby sharpening the interface between the tunnel barrier layer and the free layer.

Abstract: A method of manufacturing the magnetic head includes the steps of: forming the pole-layer-encasing layer; forming an initial nonmagnetic layer in the groove of the pole-layer-encasing layer by physical vapor deposition, the initial nonmagnetic layer being intended to become the nonmagnetic layer later by undergoing etching of a surface thereof; etching the surface of the initial nonmagnetic layer by dry etching so that the initial nonmagnetic layer becomes the nonmagnetic layer; and forming the pole layer in the pole-layer-encasing section formed by the nonmagnetic layer.

Abstract: A magnetic head includes a pole layer, first and second side shields, and an encasing layer having first to third grooves that accommodate the pole layer and the first and second side shields. A manufacturing method for the magnetic head includes the step of forming the first to third grooves in a nonmagnetic layer by using an etching mask layer having first to third openings. This step includes the steps of forming the first groove by etching the nonmagnetic layer using the first opening, with the second and third openings covered with a first mask; and forming the second and third grooves by etching the nonmagnetic layer using the second and third openings, with the first opening covered with a second mask.

Abstract: A method of forming a write pole for a magnetic recording device is provided. The method comprises providing a layer of magnetic material covered with a secondary hard mask layer and a patterned primary hard mask, milling at a first milling angle to transfer a pattern from the patterned primary hard mask to the secondary hard mask, and milling at a second milling angle to transfer the pattern from the secondary hard mask to the layer of magnetic material to form the write pole. The second milling angle is greater than the first milling angle. The method further comprises milling at a third milling angle to adjust a side wall angle of the write pole to about a desired side wall angle, and milling at a fourth milling angle to reduce a track width of the write pole to a desired track width.

Abstract: A method and system for providing a PMR transducer including an intermediate layer. The method and system include providing a hard mask layer on the intermediate layer. The hard mask layer is for a reactive ion etch of the intermediate layer. The method and system also include providing a bottom antireflective coating (BARC) layer on the hard mask layer. The BARC layer is also a masking layer for the hard mask layer. The method and system also include forming a trench in the intermediate layer using at least one reactive ion etch (RIE). The trench has a bottom and a top wider than the bottom. The method and system also include providing a PMR pole. At least a portion of the PMR pole resides in the trench.

Abstract: To provide a manufacturing method which can adjust the lengths of a recording element and a reproducing element for enabling manufacture of high-quality magnetic head sliders. The manufacturing method comprises: a stacked-layer forming step which stacks magnetic heads on a substrate; a lapping step which cuts out a bar block having a plurality of connected magnetic head sliders, and polishes a flying surface; and a slider cutting step which cuts out individual magnetic head sliders from the bar block. The stacked-layer forming step forms a reproducing-element polish amount detecting sensor on a same layer as that of the reproducing element, and forms a recording-element polish amount detecting sensor on a same layer as that of the recording element. The lapping step carries out polishing based on each output value of the reproducing-element polish amount detecting sensor and the recording-element polish amount detecting sensor.

Abstract: A method provides a magnetic transducer that includes an underlayer and a nonmagnetic layer on the underlayer. The method includes providing a plurality of trenches in the nonmagnetic layer. A first trench of corresponds to a main pole, while at least one side trench corresponds to at least one side shield. The method also includes providing mask covering the side trench(es) and providing the main pole. At least a portion of the main pole resides in the first trench. The method also includes removing at least a portion of the nonmagnetic layer residing between the side trench(es) and the main pole. The method also includes providing at least one side shield. The shield(s) extend from at least an air-bearing surface location to not further than a coil front location.

Abstract: A method for manufacturing an extraordinary magnetoresistive sensor (EMR sensor) having reduced size and increased resolution is described. The sensor includes a plurality of electrically conductive leads contacting a magnetically active layer and also includes an electrically conductive shunt structure. The electrically conductive leads of the sensor and the shunt structure can be formed in a common photolithographic masking and etching process so that they are self aligned with one another. This avoids the need to align multiple photolithographic processing steps, thereby allowing greatly increased resolution and reduced lead spacing. The EMR sensor can be formed with a magnetically active layer that can be close to or at the air bearing surface (ABS) for improved magnetic spacing with an adjacent magnetic medium of a data recording system.

Abstract: A method in one embodiment includes forming an electric lapping guide layer; forming a write pole; forming a first gap layer over the write pole; masking a portion of the first gap layer for defining a window over the write pole and at least a portion of the electric lapping guide layer; and forming a bump over the write pole in the window. Additional methods and systems are presented.

Abstract: Magnetoresistive (MR) elements having flux guides defined by the free layer. The MR element includes a free layer, a spacer/barrier layer, a pinned layer, and a pinning layer. A back edge of the free layer (opposite the sensing surface of the MR element) extends past a back edge of the spacer/barrier layer. The portion of the free layer extending past the back edge of the spacer/barrier layer defines a continuous flux guide. The flux guide is processed to reduce the conductive characteristics of the flux guide, thereby reducing current shunt loss in the flux guide.

Abstract: A method and system for providing a perpendicular magnetic recording (PMR) transducer from pole layer(s) are disclosed. First and second planarization stop layers are provided on the pole layer(s). A mask is provided on the second planarization stop layer. A first portion of the mask resides on a portion of the pole layer(s) used to form the PMR pole. The PMR pole is defined after the mask is provided. An intermediate layer surrounding at least the PMR pole is provided. A first planarization is performed on at least the intermediate layer. A portion of the second planarization stop layer is removed during the first planarization. A remaining portion of the second planarization stop layer is removed. A second planarization is performed. A portion of the first planarization stop layer remains after the second planarization. A write gap and shield are provided on the PMR pole and write gap, respectively.

Abstract: A method for manufacturing a perpendicular magnetic recording transducer is described. A metallic underlayer, an insulator on the metallic underlayer, and a metal mask on the insulator are provided. The metal mask has an aperture therein. A trench is formed in the insulator. The trench's bottom is narrower than its top and includes part of the metallic underlayer. The top has a width of not more than 0.28 micron. A nonmagnetic seed layer that substantially covers at least the trench bottom and sides and that has a thickness of at least five hundred Angstroms is provided. A perpendicular magnetic pole material is plated on at least part of the seed layer. A CMP is performed, removing part of the perpendicular magnetic pole material. A remaining portion of the perpendicular magnetic pole material forms a perpendicular magnetic recording pole. The nonmagnetic seed layer is a stop layer for the CMP.

Abstract: Methods and apparatus provide a refill configuration adjacent a back-edge that defines a height of a magnetoresistive read sensor. Milling through layers of the sensor forms the back-edge and may be initially conducted at a first angle of incidence greater than a second angle of incidence. In combination, an insulating material and a polish resistant material, such as a non-magnetic metal, disposed on the insulating material fills a void created by the milling. The sensor further includes first and second magnetic shields with the layers of the sensor along with the polish resistant material and insulating material disposed between the first and second magnetic shields.

Abstract: A method for manufacturing a magnetic write head that avoids the challenges associated with the formation of fence structures during write pole definition. A magnetic write pole material is deposited. A mask structure is deposited over the magnetic write pole material. The mask structure includes a first hard mask, a marker layer, a physically robust, inorganic RIEable image transfer layer, a second hard mask structure over the image transfer layer and a photoresist layer over the second hard mask. A reactive ion etching process can be used to transfer the image of the photoresist mask and second hard mask layer onto the image transfer layer. An ion milling is performed to define the write pole. A layer of non-magnetic material such as alumina is deposited. An ion milling is performed until the marker layer has been reached, and another reactive ion etching is performed to remove the remaining hard mask.

Abstract: A magnetic head having non-GMR shunt for perpendicular recording and method for making magnetic head having non-GMR shunt for perpendicular recording is disclosed. A shunt is provided for shunting charge from a read sensor. The shunt is formed co-planar with the read sensor and is fabricated using non-GMR materials.

Abstract: A method for manufacturing a magnetic write head having a wrap around magnetic trailing shield and a very narrow track width. A magnetic write pole is formed by forming a mask over a magnetic write pole material and performing a first ion milling to define the write pole. The mask includes a hard mask layer such as diamond like carbon (DLC) and further mask layers formed over the hard mask layer. In order to facilitate manufacture at very narrow track widths processes are employed to remove re-deposited material and the remaining portions of the mask structure (except the hard mask). Further processing can then be employed without the risk of a very narrow mask structure and redep bending or breaking during later manufacturing steps.

Abstract: In a manufacturing method of a glass substrate for a magnetic disk including a cleaning process of the glass substrate, the cleaning process includes a process of contacting the glass substrate with a cleaning solution containing a compound, such as thioglycolic acid or a thioglycolic acid derivative, having a thiol group as a functional group.

Abstract: Provided are a magnetic recording medium substrate whereupon a magnetic layer can be regularly formed in a recording area, a magnetic recording medium and a method for manufacturing the magnetic recording medium substrate. A plurality of recording areas wherein the magnetic layer is to be formed are formed on the surface of the disk-shaped magnetic recording medium substrate. The size of the recording area is an integral multiple of a lattice constant of a unit lattice of a single crystal structure constituting the magnetic layer. For instance, the width of a protruding section (3) to be used as the recording area is an integral multiple of the lattice constant of the unit lattice of the single crystal structure configuring the magnetic layer.

Abstract: A perpendicular magnetic recording (PMR) head is fabricated with a self-aligned pole tip shielded laterally by a separated pair of side shields and shielded from above by an upper shield. The side shields are formed from a shield layer by a RIE process characterized by a mask and gases producing a variety of etch rates. The differential in etch rates maintains the opening dimension within the mask and allows the formation of a wedge-shaped trench within the shield layer that then separates the layer into two shields. The pole tip is then plated within the trench and an upper shield is formed above the side shields and pole.

Abstract: A method of lapping a magnetic head slider includes a step of lapping a lapping surface of a row bar provided with a plurality of MR read head elements arranged along at least one line, a step of obtaining at least one output signal from at least one of the plurality of MR read head elements of the row bar during lapping, the at least one output signal corresponding to element resistance, a step of detecting at least one peak value of the obtained at least one output signal, and a step of controlling an amount of lapping of the row bar depending upon the detected at least one peak value.

Abstract: A manufacturing method for a magnetic head includes the steps of: forming a structure on a lower shield, the structure including a lower gap, a main magnetic pole and first and second side gaps; forming first and second side shields; forming an upper gap; and forming an upper shield. In the step of forming the structure, an initial lower gap layer is formed on the lower shield, the initial lower gap layer including a pre-lower-gap portion, and two to-be-removed portions that are located on opposite sides of the pre-lower-gap portion. Then, a protrusion including the main magnetic pole and the first and second side gaps is formed on the pre-lower-gap portion. With the top surface of the protrusion covered with a mask, the initial lower gap layer is etched in part to thereby form the lower gap.

Abstract: A method for manufacturing a magnetic write head for perpendicular magnetic recording. The method includes forming a write pole, and then depositing a refill layer. A mask structure can be formed over the writ pole and refill layer, the mask structure being configured to define a stitched pole. An ion milling or reactive ion milling can then be performed to remove portions of the refill layer that are not protected by the mask structure. Then a magnetic material can be deposited to form a stitched write pole that defines a secondary flare point. The stitched pole can also be self aligned with an electrical lapping guide in order to accurately locate the front edge of the secondary flare point relative to the air bearing surface of the write head.

Abstract: A method for manufacturing a magnetic write head for perpendicular magnetic recording, the write head having a write pole with an increased bevel (taper) angle. The write pole is constructed by forming a mask structure over a magnetic write pole material, and then performing a combination of sweeping or rotation with static (non-rotating, non-sweeping) ion milling at an angle relative to normal. The ion milling is performed while moving the wafer laterally within the ion milling tool to ensure that the ion milling is performed uniformly across the wafer during static milling.

Abstract: A method is provided for fabricating a read element with leads that overlay a top surface of a sensor of the read element. The method includes forming a mask over a sensor layer, then using the mask to define the sensor from the sensor layer. The mask is then narrowed and a lead layer is formed that overlays both ends of the top surface of the sensor without covering a center portion of the top surface.

Abstract: Methods of recording head fabrication are provided to fabricate a region of separation material between a write pole and a shield of a write head that forms a controlled spacing between the write pole and the shield of the write head. The method comprises forming a mask structure having an opening exposing a write pole of the write head and forming separation material above the portions of the write pole exposed by the opening. The method further comprises removing the mask structure and forming a shield of the write head above the separation material. The separation material forms a spacing between the write pole and the shield, which controls the amount of flux from the write pole absorbed by a shield (e.g., a wrap around shield) of the write head.

Abstract: A magnetic sensor includes a sensor stack having a first magnetic portion, a second magnetic portion, and a barrier layer between the first magnetic portion and the second magnetic portion. The first magnetic portion and/or the second magnetic portion comprises a multilayer structure including a first magnetic layer having a positive magnetostriction adjacent to the barrier layer, a second magnetic layer, and an intermediate layer between the first magnetic layer and the second magnetic layer. The magnetic sensor exhibits a magnetoresistive ratio of at least about 62% with a resistance-area (RA) product of about 0.45 ?·?m2.

Abstract: A method for manufacturing a magnetic write head that allows the location of the flare point of a write pole to be accurately located relative to the air bearing surface. The method includes the construction of a lapping guide having an edge feature that is easily and accurately located relative to the flare point of the write pole. This edge feature provides an abrupt change in electrical resistance across the lapping guide at a point when lapping should be terminated. And, since this feature can accurately located relative to the flare point, this provides an easily discernable ending point for lapping.

Abstract: A method for providing a perpendicular magnetic recording (PMR) transducer is described. The PMR transducer provided includes a PMR pole and yoke structure coupled with the PMR pole. The method includes providing a hard mask and an intermediate layer. A first portion of the hard mask resides on the PMR pole. A second portion of the hard mask resides on another structure. The intermediate layer surrounds at least the PMR pole. The method also includes performing a planarization on at least the intermediate layer, removing the first portion of the hard mask on the PMR pole without completely removing the second portion of the hard mask on the other structure. The method further includes removing a remaining portion of the hard mask on the other structure, providing a write gap on the PMR pole, and providing a shield on the write gap.

Abstract: A method of measuring a bevel angle in a write pole comprises the step of providing a mask over a wafer containing the write pole. The mask has a first opening over the write pole and a second opening over a sacrificial region of the wafer. The sacrificial region comprises a same material as the write pole. The method further comprises the steps of performing a beveling operation on the write pole and the sacrificial region to form a first bevel in the write pole and a second bevel in the sacrificial region, and measuring an angle of the second bevel in the sacrificial region to determine the bevel angle of the write pole.

Abstract: A thermally assisted magnetic head is formed by performing a head forming process, a mounting part forming process and a light source mounting process in that order. In the head forming process, a planned area is secured on a light source placing surface of a slider substrate, then a magnetic head part is formed on a head area other than the planned area and a spacer for securing a mounting space for the laser diode is formed on the planned area. In the mounting part forming process, a light source mounting part is formed by removing the spacer. In the light source mounting process, a laser diode is mounted on the light source mounting part formed by the mounting part forming step.

Abstract: Provided is a manufacturing method of heat-assisted magnetic recording head, in which a light source unit can be easily joined to a slider with sufficiently high accuracy, under avoiding the excessive mechanical stress. The manufacturing method comprises the steps of: moving relatively the light source unit and the slider, while applying a sufficient voltage between an upper electrode of the light source and an electrode layer provided in the slider; and setting the light source unit and the slider in desired positions in a direction perpendicular to the element-integration surface of the slider substrate. The desired positions are positions where the light source just emits due to a surface contact between: the protruded portion of the lower surface of the light source; and the upper surface of the electrode layer, which is a portion of the wall surface of a step formed on the head part.

Abstract: A magnetic head includes a pole layer, first and second side shields, and an encasing layer having a pole groove that accommodates the pole layer and first and second side shield grooves that accommodate the first and second side shields. In a manufacturing method for the magnetic head, the pole groove and first and second initial side shield grooves are formed in a nonmagnetic layer using an etching mask layer having first to third openings. In the manufacturing method, a wall face of the first initial side shield groove that is closer to the pole groove and a wall face of the second initial side shield groove that is closer to the pole groove are etched by dry etching to thereby complete the first and second side shield grooves.

Abstract: A PMR head comprises a substrate, a magnetic pole formed over the substrate, the pole having a pole tip having a cross-sectional tapered shape wherein the pole tip is surrounded by a write gap layer, an integrated shield comprising side shields on the substrate laterally surrounding the pole tip and a trailing shield overlying the pole tip and integral with the side shields.

Abstract: A wrap around shield of a write head is fabricated in multiple processes, with side shields fabricated in one process, and a trailing shield formed in another process. These multiple processes form a stitched wrap around shield, resulting in more flexible and accurate placement of the trailing shield and side shields with respect to the write pole. These processes also independently form the dimensions (shapes and sizes) of the side shields and the trailing shield which allows better control of writeability, saturation, and adjacent track interference of the perpendicular recording write head.

Abstract: A method for fabricating a magnetic head having multiple readers includes forming a plurality of generally laterally positioned lower shields; forming a lower gap layer above each lower shield; forming a sensor above each lower gap layer; forming an upper gap layer above each sensor; and forming an upper shield above each upper gap layer; wherein an overall gap thickness is defined between vertically aligned pairs of the upper and lower shields, wherein the overall gap thickness between one of the pairs of upper and lower shields is thicker than the overall gap thickness between another of the pairs of upper and lower shields.

Abstract: A magnetic recording head and a method of manufacturing the same. The magnetic recording head includes a stack containing a main pole and a return pole. The stack includes a first magnetic layer having a groove formed therein; an insulating layer covering a surface of the groove; and a second magnetic layer pattern filling the groove covered with the insulating layer.

Abstract: A method for manufacturing a magnetoresistive sensor that decreases the stack height of the sensor. The method includes forming a sensor structure having at its top, a Ru layer and a Ta layer over the Ru layer. An annealing process is performed to set the magnetization of the pinned layer of the sensor structure. After the annealing process has been completed and the Ta layer is no longer needed, an ion milling process is performed to remove the Ta layer.

Abstract: A perpendicular magnetic recording head and a method of manufacturing the same are provided. The perpendicular magnetic recording head that includes a main pole, a return yoke, and coils that surround upper and lower parts of the main pole in a solenoid shape so that the main pole generates a magnetic field for recording information onto a recording medium, wherein a portion of the coils that pass above the main pole comprises a plurality of first coils and at least one second coil having a cross-sectional shape different from that of the first coils, and the second coil is formed across upper regions of two first coils adjacent to each other among the first coils.

Abstract: Write elements and methods of fabricating magnetic write poles are described. For one method, a vertical mask structure is formed on a magnetic layer in locations of a pole tip and a yoke of a write pole. The vertical mask structure may be formed by coating vertical surfaces of resists with an atomic layer deposition (ALD) process or a similar process. A removal process is then performed around the vertical mask structure to define the pole tip and part of the yoke of the write pole, and the vertical mask structure is removed. A lower portion of the pole tip is them masked while the upper portion of the pole tip and the part of the yoke is exposed. The upper portion of the pole tip and the part of the yoke are then expanded with magnetic material, such as with a plating process.

Abstract: A method for forming a tapered, electroplated structure. The method involves forming a first mask structure having an opening. A shrink material is deposited into the opening, such that the thickness of the shrink material is less than the thickness of the first mask structure. The first mask structure and the shrink material are then heated causing the sides of the opening in the mask structure to bulge inward. The shrink material is then removed, and a first electrically conductive material can then be electroplated into the opening to a thickness that is much less than the thickness of the mask. The bulbous shaped of the deformed photoresist mask forms a taper on the first electrically conductive material. The first mask can then be removed and a second electrically conductive material can be electroplated over the first electrically conductive material.

Abstract: A “scissoring-type” current-perpendicular-to-the-plane (CPP) magnetoresistive sensor with dual ferromagnetic sensing or free layers separated by a nonmagnetic spacer layer has improved stability as a result of etch-induced uniaxial magnetic anisotropy in each of the free layers. Each of the two ferromagnetic free layers has an etch-induced uniaxial magnetic anisotropy and an in-plane magnetic moment substantially parallel to its uniaxial anisotropy in the quiescent state, i.e., the absence of an applied magnetic field. The etch-induced uniaxial anisotropy of each of the free layers is achieved either by direct ion etching of each of the free layers, and/or by ion etching of the layer on which each of the free layers is deposited. A strong magnetic anisotropy is induced in the free layers by the etching, which favors generally orthogonal orientation of the two free layers in the quiescent state.

Abstract: A method for providing a perpendicular magnetic recording head includes providing a metal underlayer and forming a trench in the metal underlayer. The trench has a bottom and a top wider than the bottom. The method also includes providing a PMR pole. At least a portion of the PMR pole resides in the trench. The method also includes providing a write gap on the PMR pole and providing a top shield on at least the write gap.

Abstract: Improved writability and a reduction in adjacent track erasure are achieved in a PMR writer with a large flare angle of 45 and 90 degrees in the main write pole and a full side shield or partial side shield configuration around the narrow write pole section and write pole tip. A trailing shield is formed above the write pole's top surface and a full or partial side shield section is spaced a certain distance from each side of the write pole. The partial side shield has a thickness less than that of the write pole and a top or bottom surface about coplanar with the pole tip's top or bottom edge, respectively. The partial side shield may include two sections on each side of the write pole wherein the bottom surface of a top section is separated by a certain distance from the top surface of a bottom section.

Abstract: A method for manufacturing a manufacturing a magnetoresistive sensor that allows the sensor to be constructed with a very narrow and well controlled track width. The method includes depositing a layer of diamond like carbon over a series of sensor layers. A first mask is then formed to define a sensor, and an ion milling is performed to remove sensor material not protected by the first mask. Then, a second mask is formed, and a hard bias layer is deposited to the thickness of the sensor layers. The second mask is then lifted off and a CMP is performed to remove the first mask structure. Because all areas other than the area directly over the sensor are substantially planar a quick, gentle CMP can be used to remove the first mask layer even if the first mask is small, such as for definition of a very narrow track-width sensor.