Tolerances for manufacturing reader structures for transducer heads continue to grow smaller and storage density in corresponding storage media increases. Reader stop layers may be utilized during manufacturing of reader structures to protect various layers of the reader structure from recession and/or scratches while processing other non-protected layers of the reader structure. For example, the stop layer may have a very low polish rate during mechanical or chemical-mechanical polishing. Surrounding areas may be significantly polished while a structure protected by a stop layer with a very low polish rate is substantially unaffected. The stop layer may then be removed via etching, for example, after the mechanical or chemical-mechanical polishing is completed.

SUMMARY

Implementations described and claimed herein provide a layered magnetic structure comprising one or more stop-layers that resist mechanical polishing of the layered magnetic structure without substantial degradation and yield to chemical etching of the layered magnetic structure.

Other implementations provide a method of manufacturing a layered magnetic structure, comprising: depositing a stop-layer over a protected component of the layered magnetic structure; and mechanically polishing material adjacent the protected component without causing significant recession of the stop layer.

Still other implementations provide a read element comprising: one or more stop-layers that resist mechanical polishing of the read element without degradation and yield to chemical etching of the read element, wherein at least one of the one or more stop layers are deposited within a vacuum over one or more free layers and spacer layers of the read element.

DETAILED DESCRIPTIONS

Information and communication systems increasingly handle huge amounts of data, placing heavy demands on magnetic media storage capacity and performance. A transducer head on a magnetic storage media typically includes a read element for retrieving magnetically encoded information stored on a magnetic disc. Magnetic flux from a surface of the magnetic disc causes rotation of a magnetization vector of one or more sensing layers of the read element, which in turn causes a change in electrical resistivity of the read element. The changes in electrical resistivity of the read element are correlated to the magnetically encoded information stored on the magnetic disc. Improvements in magnetic storage media technology allow areal recording densities on the magnetic discs that are available today. However, as areal recording densities increase, smaller, more sensitive read element heads are desired. As the read elements are made smaller and more sensitive, one or more stop-layers may be used during read element manufacturing to protect some layers of the read element while simultaneously processing other layers of the read element.

FIG. 1illustrates an example air-bearing surface of a transducer head100with a read element102manufactured using one or more stop-layers (not shown). The transducer head100is a laminated structure with a variety of layers performing a variety of functions. A nonmagnetic, non-conductive substrate104(e.g., Al2O3, aluminum oxide, or alumina) serves as a mounting surface for the transducer head100components and connects the transducer head100to an air-bearing slider (ABS) (not shown). A read element102is sandwiched between lower shield106and an upper shield108. Shields106,108isolate the read element102from electromagnetic interference, primarily y-direction interference, and serve as electrically conductive first and second electrical leads connected to processing electronics (not shown). In one implementation, shields106,108are constructed of a soft magnetic material (e.g., a Ni—Fe alloy).

Further, the lower shield106incorporates an alumina insert120. The alumina insert120is protected during manufacturing using one or more stop layers (e.g., ruthenium, chromium, and tantalum layers). The stop layers have very low and consistent polish rate under abrasive polishing (e.g., polishing with an abrasive slurry) and chemical-mechanical polishing (e.g., polishing with an abrasive and corrosive chemical slurry). In one implementation, the stop layers resist substantial recession during abrasive polishing and/or chemical-mechanical polishing (e.g., has a recession rate of less than 2 Angstroms per minute). Further, the stop layers may readily dissolve in etching processes. In other implementations, the upper shield108incorporates an alumina insert in addition or in lieu of the alumina insert120. The lower shield106and/or read element102may also be protected during manufacturing using one or more stop layers.

Resistance of the read element102changes as magnetic regions on a magnetic media come in close proximity to the read element102. When sense current is conducted through the read element102between the two shields106,108, changes in read element102resistance yields changes in readback voltage that are tracked by the processing electronics. Thus, the readback voltage corresponds to polarity of the magnetic regions on the media.

The transducer head100also includes nonmagnetic, non-conductive insulation layers112(e.g., alumina), which electrically isolate the lower shield106and the read element102from soft magnetic or non-magnetic metallic side shields110. As a result, substantially all the current flowing between the shields106,108must pass through the read element102. The alumina insert120tunes the electrical resistance between the shields106,108to a desired level. Further, the length of the read element102in the z-direction (i.e., stripe height) affects the overall resistance of the read element102. As a result, alumina insert120size and shape as well as the stripe height may be optimized to provide a desired level of resistance and desired response amplitude. Further, the side shields110isolate the read element102from electromagnetic interference, primarily x-direction interference and/or z-direction interference.

The transducer head100also includes a barrier layer114between a coil116and the shield108. The coil116in combination with a write pole118receives a write signal from the processing electronics and changes the magnetic polarization of magnetic regions on an adjacent magnetic media (not shown), thereby writing the data from the write signal to the magnetic media.

Portions of the soft magnetic side shield110, the upper shield108, and the barrier layer114are shown as removed in the close-up view ofFIG. 1for clarity purposes. The read element102is depicted as a trilayer read element. More specifically, the read element102includes at least three laminated metallic layers: a first ferromagnetic free layer124, a nonmagnetic spacer layer126, and a second ferromagnetic free layer128. The read element102is capped with a stop layer130to prevent recession of the trilayer stack during manufacturing processes. The free layers124,128each may be composed of magnetic materials such as nickel-iron-cobalt (Ni—Fe—Co) alloys. The stop layer130may be composed of particularly hard and non-reactive metals (e.g., ruthenium, chromium, and tantalum layers). In various implementations, the spacer layer126may be relatively electrically conducting or non-conducting and serves to magnetically separate the free layers124,128from one another. Further, the read element102is depicted with an expanding width in the x-direction with depth in the negative z-direction.

Magnetic flux from a surface of the magnetic media causes rotation of a magnetization vector of each of the free layers124,128of the read element102, which in turn causes a change in electrical resistivity of the read element102between shields106,108. The changes in electrical resistivity of the read element102are correlated to magnetically polarized regions on the magnetic media, which in turn correspond to stored data on the magnetic media.

The polarity of each of the free layers124,128is affected by nearby magnetic fields. A magnet122is mounted behind (in the negative z-direction) the read element102. Other locations of the magnet122are contemplated herein. The magnet122may be fabricated from permanent magnet material such as a cobalt-platinum (Co—Pt) alloy. The magnet122biases the magnetization of each of the two free layers124,128generally parallel to the magnetic media and converging in a “scissor-like” orientation with respect to one another. As the free layers124,128pass in close proximity to polarized magnetic regions on the adjacent magnetic media, the polarization of the magnetic regions affects the polarity of each of the free layers124,128and in turn affects read element102resistance between the shields106,108. More specifically, a first magnetic region polarization may increase the angle of magnetization between the two free layers124,128and a second magnetic region polarization may decrease the angle of magnetization between the two free layers124,128. Sense current flows into the read element sensor through the shields106,108(which act as electrodes) and a change in resistance affects a readback voltage. As a result, the magnetic orientation of data on the magnetic media is detected by changes in the readback voltage.

One implementation of the presently disclosed technology utilizes the following materials and thicknesses. The free layers124,128may be made of various alloys containing nickel, iron, cobalt, and/or boron and have thicknesses ranging from 20-50 A, for example. The spacer layer244may be made of alumina, zinc oxide, calcium oxide, and/or magnesium oxide and have a thickness ranging from 0-10 A, for example. The side shields110may be made of NiFe alloys and have a thickness ranging from 50-200 A, for example. Each of the top and bottom shields106,108may be made of NiFe alloys and have a thickness ranging from 1-2 microns, for example.

Other implementations of a read element102have a variety of size and shape orientations. The size and shape of read element102is an example only. The presently disclosed technology may also be used with read element types other than trilayer read elements as depicted herein (e.g., anistropic magnetoresistive (AMR) sensors, giant magnetoresistive (GMR) sensors including spin valve sensors and multilayer GMR sensors, and tunneling giant magnetoresistive (TGMR) sensors).

The transducer head100is configured to be attached to an air-bearing slider (not shown) at a distal end of an actuator arm flexure (not shown). The slider enables the transducer head100to fly in close proximity above a corresponding surface of the adjacent magnetic media. The air-bearing surface of the transducer head100is configured to face the magnetic media. The actuator arm flexure is attached to a cantilevered actuator arm (not shown) and the actuator arm flexure is adjustable to follow one or more tracks of magnetic data on a magnetic media (not shown). Electrical wires (not shown) extend along the actuator arm flexure and attach to contact pads (not shown) on the slider that ultimately connect to the transducer head100. Read/write and other electrical signals pass to and from processing electronics (not shown) to the transducer head100via the electrical wires and contact pads.

FIG. 2Aillustrates an example air-bearing surface of a lower shield206. The lower shield206is shown as viewed from a magnetic media looking upwards at the air-bearing surface (x-y plane) of the lower shield206. The lower shield206functions as a first electrical connection for conducting a sense current through a read element perpendicular to the major planes of the layers of a read element. Sides and a bottom of the lower shield206are surrounded by a nonmagnetic, non-conductive substrate204(e.g., alumina). The substrate204serves as a mounting surface for the read element components (e.g., the lower shield206) and connects the read element to an air-bearing slider (ABS) (not shown). In one implementation, the lower shield206is polished before further processing as described below.

FIG. 2Billustrates the example lower shield206ofFIG. 2Awith a shield stop-layer232deposited thereon. The shield stop-layer232is deposited over the lower shield206and the surrounding substrate204to prevent recession of the lower shield206during manufacturing processes. The lower shield206may be referred to herein as a protected layer when referencing shield stop-layer232. The stop layer232may be composed of particularly hard and non-reactive metals (e.g., ruthenium, chromium, and tantalum layers) that resist chemical-mechanical polishing (CMP) processes. In one implementation, the stop layer232is thin enough to be transparent (i.e., between 5 and 100 angstroms). The components ofFIGS. 2A and 2Bare not drawn to scale and may omit portions of a transducer head (not shown) and/or read element (not shown) for clarity of the illustrations.

FIG. 3Aillustrates an example air-bearing surface of a lower shield306with a shield stop-layer332, a carbon layer334, and a photo-resist layer336deposited thereon. The carbon layer334and the photo-resist layer336are applied on top of the stop-layer332and have a semi-circular void pattern. The semi-circular void pattern is intended to aid application of an alumina insert discussed in detail below. In other implementations, the alumina insert has a profile other than semi-circular. Thus, the void pattern in the carbon layer334and the photo-resist layer336will vary depending upon the intended shape of the alumina insert.

FIG. 3Billustrates the example lower shield306, shield stop-layer332, carbon layer334, and photo-resist layer336ofFIG. 3Awith a depression338formed in the lower shield306. The depression338may be formed using ion milling. The photo-resist layer336protects areas of the lower shield306covered by the photo-resist layer336from the ion milling process. The depression338receives an alumina insert as discussed in detail below. The components ofFIGS. 3A and 3Bare not drawn to scale and may omit portions of a transducer head (not shown) and/or read element (not shown) for clarity of the illustrations.

FIG. 4Aillustrates an example air-bearing surface of a lower shield406with a shield stop-layer432, a carbon layer434, a photo-resist layer436, and an alumina layer442deposited thereon. The alumina layer442is deposited over the photo-resist layer436and within a depression438in the lower shield406. The alumina layer442at least fills the depression438and may exceed the depth of the depression438. The alumina layer442deposited inside the depression438is referred to herein as the alumina insert420.

FIG. 4Billustrates the example lower shield406, shield stop-layer432, carbon layer434, photo-resist layer436, alumina layer442, and alumina insert420ofFIG. 4Awith an insert stop layer440deposited thereon. The insert stop layer440is deposited over the alumina layer442and the alumina insert420and is intended to protect the alumina insert420from recession during polishing operations around the depression338as described in detail below. The alumina insert420may be referred to herein as a protected layer when referencing insert stop layer440. The insert stop layer440may be composed of particularly hard and non-reactive metals (e.g., ruthenium, chromium, and tantalum layers) that resist chemical-mechanical polishing (CMP) processes. In one implementation, the insert stop layer440is thin enough to be transparent (i.e., between 5 and 100 angstroms). The components ofFIGS. 4A and 4Bare not drawn to scale and may omit portions of a transducer head (not shown) and/or read element (not shown) for clarity of the illustrations.

FIG. 5Aillustrates an example air-bearing surface of a lower shield506with a shield stop-layer532and a carbon layer534deposited thereon, wherein re-deposition544formed from removal of one or more layers (e.g., the photo-resist layer436and/or alumina layer442) are formed about an alumina insert520protruding from a depression538formed in the lower shield. The photo-resist layer436and/or alumina layer442ofFIG. 4are removed, leaving re-deposition544of material surrounding the depression538. In some implementations, the photo-resist layer436(and above alumina layer442) is removed using a solvent, which does not affect any of the other layers. As a result, imperfections in the milling of depression538, application of the alumina insert520, and application of an insert stop layer540are revealed when the photo-resist layer436and/or alumina layer442are removed.

FIG. 5Billustrates the example lower shield506, shield stop-layer532, carbon layer534, alumina insert520, and insert stop-layer540ofFIG. 5Awith the re-deposition544removed. The re-deposition544may be removed with abrasive polishing and/or chemical-mechanical polishing of the carbon layer534. The insert stop-layer540prevents the abrasive polishing and/or chemical-mechanical polishing from significantly removing material from the alumina insert520. In one implementation, the re-deposition544are up to 50 nm tall (in the y-direction) and the insert stop-layer540is approximately 2 nm thick (in the y-direction). The 2 nm thick is sufficient to resist abrasive polishing and/or chemical-mechanical polishing of the 9 nm tall re-deposition544. The components ofFIGS. 5A and 5Bare not drawn to scale and may omit portions of a transducer head (not shown) and/or read element (not shown) for clarity of the illustrations.

FIG. 6Aillustrates an example air-bearing surface of a lower shield606with a shield stop-layer632deposited thereon and a stop layer640capped alumina insert620protruding from a depression638formed in the lower shield606, with a carbon layer removed. The carbon layer534ofFIGS. 5A and 5Bis removed inFIG. 6A. The carbon layer534may be removed with a plasma etching process, an acid etching process, or a chemical-mechanical polishing process, for example. The shield stop-layer632protects the lower shield606from recession during removal of the carbon layer. The insert stop layer640protects the alumina insert620from recession during removal of the carbon layer. After the carbon layer is removed, an offset between the insert stop layer640and the shield stop-layer632in the y-direction is revealed. A gap646that is not covered by stop layer material exists at the interface between the lower shield606and the alumina insert620.

FIG. 6Billustrates the air-bearing surface of the lower shield606and the alumina insert620ofFIG. 6A, wherein some or all of the alumina insert620that had been protruding above the air-bearing surface of the lower shield606is removed. While the x-z planar top surface of the alumina insert620is protected from abrasive polishing and/or chemical-mechanical polishing by insert stop layer640, the protruding portion of the alumina insert620may be removed by a side-milling process (i.e., milling in the x-z plane). The side milling utilizes a gap between the insert stop layer640and a shield stop-layer632that is not covered by a stop layer material (see e.g., gap646ofFIG. 6A) to mill alumina underneath the shield stop-layer632and thus remove the portion of the alumina insert620protruding above the air-bearing surface of the lower shield606.

As a result, the insert stop layer640is removed with the portion of the alumina insert620protruding above the air-bearing surface of the lower shield606. The alumina insert620may also be polished at this point. The shield stop-layer632may protect the polished lower shield606from scratches caused by polishing the alumina insert620. In one implementation, a 3 nm thick (in the y-direction) shield stop-layer632is sufficient to prevent polishing of the alumina insert620from scratching the lower shield606. The components ofFIGS. 6A and 6Bare not drawn to scale and may omit portions of a transducer head (not shown) and/or read element (not shown) for clarity of the illustrations.

FIG. 7Aillustrates an example air-bearing surface of a lower shield706with a shield stop-layer (see shield stop-layer ofFIG. 632) removed and an alumina insert720in the lower shield706reduced to a common plane with the lower shield706. The shield stop-layer may be removed using an etchant, leaving the alumina insert720coplanar in the x-z plane with the lower shield706. In other implementations, the shield stop-layer may remain and assist deposition of a read element (see below).

FIG. 7Billustrates the air-bearing surface of the lower shield706and the alumina insert720ofFIG. 7Awith a tri-layer read element702and a read element stop-layer730deposited thereon. The tri-layer read element702includes at least three laminated metallic layers: a first ferromagnetic free layer724, a nonmagnetic spacer layer726, and a second ferromagnetic free layer728. The read element702is capped with a stop layer730to prevent recession of the tri-layer read element702during manufacturing processes. One or more layers of the read element702may be referred to herein as a protected layer when referencing read element stop-layer730. Portions of the first ferromagnetic free layer724, the nonmagnetic spacer layer726, the second ferromagnetic free layer728, and the stop layer730are shown as removed in the close-up view ofFIG. 7Bfor clarity purposes. For example, the first ferromagnetic free layer724, the nonmagnetic spacer layer726, the second ferromagnetic free layer728, and the stop layer730may cover 90% of a corresponding wafer before additional processing is completed on the tri-layer read element702.

The read element stop-layer730may be composed of particularly hard and non-reactive metals (e.g., ruthenium, chromium, and tantalum layers) that resist chemical-mechanical polishing (CMP) processes. In one implementation, the insert stop layer440is thin enough to be transparent (i.e., approximately 5 to 100 angstroms).

In one implementation, each layer of the tri-layer read element702and the read element stop-layer730are deposited together without breaking a vacuum during the deposition process. This ensures that the read element stop-layer730adheres to the top layer of the tri-layer read element702without an oxidation layer there between. The components ofFIGS. 7A and 7Bare not drawn to scale and may omit portions of a transducer head (not shown) and/or read element (not shown) for clarity of the illustrations.

FIG. 8Aillustrates an example air-bearing surface of a lower shield806and an alumina insert820with a tri-layer reader802, a reader stop-layer830, and a photo-resist layer836deposited thereon. The photo-resist layer836covers at least the tri-layer reader802and the reader stop-layer830. The photo-resist layer836may also cover surrounding substrate804material.

FIG. 8Billustrates the lower shield806, the alumina insert820, the tri-layer reader802, the reader stop-layer830, and the photo-resist layer836ofFIG. 8A, with a photo mask848placed over the photo-resist layer836. The photo mask848is applied on top of the photo-resist layer836and has a shape resembling a triangle with a rectangular extension from one of the points of the triangle. The photo-resist layer836shape is intended to pattern the final shape of the tri-layer reader802as discussed in detail below. In other implementations, the tri-layer reader802has a profile other than shown inFIG. 1B, for example. Thus, the photo-resist layer836shape will vary depending upon the intended shape of the tri-layer reader802.

The photo mask848selectively shields the photo-resist layer836from exposure to light during photolithography. The light develops areas of the photo-resist layer836that are exposed. In one implementation, the photo mask848includes glass and chrome portions. The glass portions allow light to penetrate to the photo-resist layer836. The chrome portions reflect away light and shields the photo-resist layer836from the light. In a glass and chrome photo mask848, the shape resembling a triangle with a rectangular extension from one of the points of the triangle corresponds to the chrome or photo-transparent portion of the photo mask848, depending on whether the photo-resist layer836is a positive photo-resist or a negative photo-resist. More specifically, a positive photo-resist becomes soluble when exposed to light and a negative photo-resist becomes insoluble when exposed. A developer removes the insoluble material. The components ofFIGS. 8A and 8Bare not drawn to scale and may omit portions of a transducer head (not shown) and/or read element (not shown) for clarity of the illustrations.

FIG. 9Aillustrates an example air-bearing surface of a lower shield906and an alumina insert920with a tri-layer reader902, a reader stop-layer930, and a photo-resist structure936defined by a photo mask (see photo mask848ofFIG. 8B). Areas of the photo-resist structure936not protected from exposure to light by a photo mask are developed by photolithography. In one implementation, photolithography does not develop any of the reader stop-layer930. The reader stop-layer930may protect top layers of the tri-layer reader902from the photolithography. A photo-resist structure936with a shape resembling a triangle with a rectangular extension from one of the points of the triangle remains after photolithography.

FIG. 9Billustrates the lower shield906and the alumina insert920ofFIG. 9Awith areas of the tri-layer reader902and the reader stop-layer930not protected by the photo-resist structure936removed. In one implementation, an ion-milling process removes areas of the reader stop-layer930and tri-layer reader902not covered by the photo-resist structure936. As a result, the tri-layer reader902and the reader stop-layer930have a shape resembling a triangle with a rectangular extension from one of the points of the triangle remains after ion-milling. The shape corresponds to the photo mask848shape ofFIG. 8B. The components ofFIGS. 9A and 9Bare not drawn to scale and may omit portions of a transducer head (not shown) and/or read element (not shown) for clarity of the illustrations. In some implementations, an additional reader stop-layer may be applied to the sides of the tri-layer reader902to further protect the tri-layer reader902from recession.

FIG. 10Aillustrates an example air-bearing surface of a lower shield1006and an alumina insert1020with a tri-layer reader structure1002, a reader stop-layer1030, and a photo-resist structure1036covered by an alumina layer1050. The alumina layer1050may also overlap onto surrounding substrate1004. The alumina layer1050forms the insulation layers112depicted inFIG. 1. The alumina layer1050electrically isolates the lower shield1006and the tri-layer reader structure1002from soft magnetic side shields (see non-magnetic metallic layer1052ofFIG. 10B). In one implementation, the alumina layer1050is thin enough to be transparent (e.g., between 10 and 90 angstroms).

FIG. 10Billustrates the lower shield1006, the alumina insert1020, the tri-layer reader structure1002, the reader stop-layer1030, the photo-resist layer1036, and the alumina layer1036ofFIG. 10Awith a metallic layer1052deposited thereon. The non-magnetic or soft magnetic metallic layer1052fills in areas adjacent the tri-layer reader structure1002that were previously milled away. The metallic layer1052forms the side shields110depicted inFIG. 1. The metallic layer1052isolates the tri-layer reader structure1002from electromagnetic interference.

FIG. 11illustrates an example air-bearing surface of a lower shield1106and an alumina insert1120with a tri-layer reader structure1102, a reader stop-layer1130, an alumina layer1150, and a metallic layer1152, with portions of the metallic layer1152, the alumina layer1150, and a photo-resist layer (not shown) above the tri-layer reader structure removed and re-deposition1144remaining. A side milling operation (milling in the x-y plane) removes an exposed portion of the alumina layer1150adjacent the photo-resist layer (see exposed portion of the photo-resist layer1036ofFIG. 10B). The photo-resist layer then is then removed and the alumina layer1150and non-magnetic or soft magnetic metallic layer1152above (in the y-direction) the reader stop-layer1130are lifted away. Re-deposition1144of material may remain. In some implementations, the photo-resist layer is removed using a solvent, which does not affect any of the other layers. As a result, imperfections in the milling of alumina layer1150, for example are revealed when the photo-resist layer is removed.

The re-deposition1144may be removed with abrasive polishing and/or chemical-mechanical polishing of the exposed portions of the metallic layer1152, alumina layer1150, and reader stop-layer1130. The reader stop-layer1130prevents the abrasive polishing and/or chemical-mechanical polishing from significantly removing material from the tri-layer reader structure1102. In one implementation, a 40-second chemical-mechanical polishing operation is sufficient to remove the re-deposition and not significantly recess the tri-layer reader structure1102. For example, an approximately 8 nm thick reader stop-layer1130can resist the 40-second chemical-mechanical polishing operation. Optionally, the reader stop-layer1130may be chemically etched away after the abrasive polishing and/or chemical-mechanical polishing. The components ofFIGS. 11A and 11Bare not drawn to scale and may omit portions of a transducer head (not shown) and/or read element (not shown) for clarity of the illustrations.

FIG. 12illustrates example operations1200for preparing a lower shield with an integrated alumina insert for manufacturing a read element using one or more stop-layers. A polishing operation1205polishes a lower shield for the read element. An applying operation1210applies a stop-layer over the lower shield. The stop-layer protects the lower shield from scratches during further manufacturing processes as discussed below. As such, the lower shield may be referred to as a protected layer. The stop-layer may comprise Ruthenium or other hard non-magnetic materials.

A second applying operation1215applies a carbon layer and a photo-resist layer over the lower shield. Each of the carbon layer and a photo-resist layer have a patterned void that patterns an alumina insert in the lower shield as discussed in detail below. A milling operation1220mills a depression in the lower shield through the void in the carbon layer and the photo-resist layer. The depression is intended to receive the alumina insert as discussed below. A depositing operation1225deposits an alumina layer over the photo-resist layer and within the depression in the lower shield. The alumina layer at least fills the depression in the lower shield and may exceed the depth of the depression in the lower shield, thus forming an alumina insert.

A second depositing operation1230deposits a stop-layer over the alumina layer. The stop-layer protects the alumina insert from recession during further manufacturing processes as discussed below. As such, the alumina insert may be referred to as a protected layer. The stop-layer may comprise Ruthenium or other hard non-magnetic materials. A removing operation1235removes the photo-resist layer and the portion of the alumina layer and stop-layer deposited on the photo-resist layer. Removing operation1235leaves re-deposition spikes of material around the void in the carbon layer and alumina insert.

A second polishing operation1240polishes the re-deposition spikes around the void in the carbon layer and the alumina insert. The stop-layer over the alumina insert prevents the second polishing operation1240from causing recession of the alumina insert. A removing operation1245removes the carbon layer leaving the stop-layer capped alumina insert slightly protruding above the stop layer capped lower shield.

A side milling operation1250side mills the alumina insert within the depression in the lower shield. The side milling operation1250operates through a gap in the stop-layer over the alumina insert and the stop layer over the lower shield. The side mill removes the portion of the alumina insert protruding beyond the lower shield. The top-layer over the alumina insert is also removed by removing the alumina insert protruding beyond the lower shield. The alumina insert may also be polished at this point. An etching operation1255etches away any remaining stop-layer material on the alumina insert and/or the lower shield. In some implementations, the etching operation1255is not performed and the stop-layer material on the alumina insert and/or the lower shield is left remaining.

FIG. 13illustrates example operations1300for depositing a read element onto a lower shield with an integrated alumina insert using one or more stop-layers. A deposition operation1305deposits a reader structure including reader stack layers with a stop-layer on top of the reader stack layers. In one implementation, the read element is a tri-layer reader. The stop-layer protects the read element from recession during further manufacturing processes as discussed below. As such, one or more layers of the read element may be referred to as protected layers. The stop-layer may comprise Ruthenium or other hard non-magnetic materials.

A coating operation1310coats the reader structure and surrounding substrate with a photo-resist layer. A placing operation1315places a mask over the reader structure patterning a read element. In one implementation, the mask includes glass and chrome portions. The glass portions allow light to penetrate to the photo-resist layer. The chrome portions reflect away light and shields the photo-resist layer from the light. A photo-etching operation1320photo-etches the photo-resist away leaving a read element shaped photo-resist layer under the mask.

A milling operation1325mills away the reader stack layers that are not under the reader element shaped photo-resist layer. This forms the general shape of the read element. A second depositing operation1330deposits a layer of alumina over the read element and surrounding the lower shield. This layer of alumina forms the insulation layers112depicted inFIG. 1, for example. The alumina layer electrically isolates the lower shield and the read element from soft magnetic side shields (see non-magnetic metallic layer below).

A third depositing operation1335deposits a non-magnetic or soft-magnetic metallic filler material adjacent to and on top of the read element. The metallic filler material forms the side shields110depicted inFIG. 1. The metallic filler material isolates the tri-read element from electromagnetic interference. A removing operation1340removes the photo-resist layer over the read element with the alumina and metallic filler material on top of the photo-resist layer removed as well. Removing operation1340leaves re-deposition spikes of material on top of the read element.

Polishing operation1345polishes the re-deposition spikes remaining on top of the reader stack without degrading the top layer of the reader stack. The stop-layer over the reader stack prevents the polishing operation1345from causing recession of the reader stack. In some implementations, the stop-layer over the reader stack is etched away after polishing operation1345.

The above specification, examples, and data provide a complete description of the structure and use of exemplary embodiments of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. Furthermore, structural features of the different embodiments may be combined in yet another embodiment without departing from the recited claims.