Abstract: A magnetic head having a spin valve sensor that is fabricated utilizing an Al2O3, NiMnO, NiFeCr seed layer upon which a typical PtMn spin valve sensor layer structure is subsequently fabricated. The preferred embodiment fabrication process of the NiFeCr layer includes the overdeposition of the layer to a first thickness of from 15 ? to 45 ? followed by the etching back of the seed layer of approximately 5 ? to approximately 15 ? to its desired final thickness of approximately 10 ? to 40 ?. The Cr at. % composition in the NiFeCr layer is preferably from approximately 35 at. % to approximately 46 at. %. The crystal structure of the surface of the etched back NiFeCr layer results in an improved crystal structure to the subsequently fabricated spin valve sensor layers, such that the fabricated spin valve exhibits increased ?R/R and reduced coercivity.

Abstract: A magnetoresistive sensor having a novel laminated hard bias structure that possesses exceptional magnetic performance characteristics when deposited over a crystalline structure such as in a partial mill sensor design in which a portion of a sensor stack extends beyond the active area of the sensor. The hard bias structure may include a seed layer comprising a layer of Si sandwiched between layers of CrMo. The hard bias structure, which can be formed over the seed layer structure, includes layers of CoPt separated a layer of CrMo.

Abstract: A method for constructing a magnetoresistive sensor that avoids shadowing effects of a mask structure during sensor definition. The method includes the use of an antireflective coating (ARC) and a photosensitive mask deposited there over. The photosensitive mask is formed to cover a desired sensor area, leaving non-sensor areas exposed. A reactive ion etch is performed to transfer the pattern of the photosensitive mask onto the underlying ARC layer. The reactive ion etch (RIE) is performed with a relatively high amount of platen power. The higher platen power increases ion bombardment of the wafer, thereby increasing the physical (ie mechanical) component of material removal relative to the chemical component. This increase in the physical component of material removal result in an increased rate of removal of the photosensitive mask material relative to the ion mill resistant mask.

Abstract: A spin valve sensor includes a spacer layer which is located between a free layer and an antiparallel (AP) pinned layer structure wherein the AP pinned layer structure includes an antiparallel coupling layer which is located between and interfaces first and second AP pinned layers with the second AP pinned layer interfacing the spacer layer. Each of the first and second AP pinned layers is composed of cobalt iron (CoFe) wherein the iron (Fe) content in the cobalt iron (CoFe) of one of the first and second AP pinned layers is greater than the iron (Fe) content in the cobalt iron (CoFe) in the other one of the first and second AP pinned layers.

Abstract: A magnetoresistive sensor having improved pinned layer stability at small track widths. The sensor has substantially vertical side walls that define the track width of the sensor. The free layer terminates at the substantially vertical side walls, but the pinned layer structure or a portion thereof extends beyond the track width region into the field. The extended pinned layer structure provides improved resistance to amplitude flipping, while allowing the track width to remain small.

Abstract: A magnetoresistive sensor having a novel seed layer that allows a bias layer formed there over to have exceptional hard magnetic properties when deposited over a crystalline structure such as an AFM layer in a partial mill sensor design. The seed layer structure includes alternating layers of Ru and Si and a layer of CrMo formed thereover. The seed layer interrupts the epitaxial growth of an underlying crystalline structure, allowing a hard magnetic material formed over the seed layer to have a desired grain structure that is different from that of the underlying crystalline layer. The seed layer is also resistant to corrosion, providing improved sense current conduction to the sensor.

Abstract: A magnetic head including an electrical lead layer that is comprised of a material having an ordered-phase crystalline structure. In a preferred embodiment, the ordered-phase crystalline structure of the electrical lead is epitaxially matched to the crystalline structure of the hard bias layer upon which it is formed, and there is no need for a seed layer for the electrical leads. Electrical leads comprised of the materials used in the invention having an ordered-phase crystalline structure, particularly a B2, L10, L11, and L12 structure, will have significantly reduced resistivity over the prior art electrical leads that are typically composed of rhodium or tantalum. As a result, thinner electrical leads can be fabricated which carry the same, or even greater, current than the prior art rhodium or tantalum leads. The preferred leads are comprised of NiAl, FeCo, or CuZn having a B2 crystalline structure, and alternative embodiments are comprised of CuAu, Cu3Au, CuPt, and Cu3Pt.

Abstract: In one illustrative example, a method of making a read sensor of a magnetic head involves forming a barrier structure which surrounds a central mask formed over a plurality of read sensor layers; etching the read sensor layers to form the read sensor below the mask; and depositing, with use of the mask and the barrier structure, hard bias and lead layers to form around the read sensor. The barrier structure may be formed by, for example, depositing one or more barrier structure layers over the read sensor layers and performing a photolithography process. The barrier structure physically blocks materials being deposited at relatively low angles (e.g. angles at or below 71 degrees) so as to reduce their formation far underneath the mask (e.g. when using a bridged mask), which could otherwise form an electrical short, and/or to improve the symmetry of the deposited materials around the read sensor.

Abstract: A method makes a spin valve sensor of a magnetic read head which includes the steps of forming a ferromagnetic pinned layer structure that has a magnetic moment, forming a pinning layer exchange coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure, forming a free layer structure, forming a nonmagnetic electrically conductive spacer layer between the free layer and the pinned layer structure and the forming of the free layer structure including the step of sputter depositing at least a first free layer composed of cobalt iron directly on the spacer layer in a nitrogen atmosphere.

Abstract: A lead overlay magnetic sensor for use in a disk drive is provided having a protective cap layer disposed between the electrical leads and the sensor. The protective cap layer is preferably formed from ruthenium, rhodium, or other suitable material. The sensors thus formed have low resistance between the electrical leads and the sensor and also have well defined magnetic trackwidths.

Abstract: An electrical connection structure suitable for use in a magnetic head and disk drive, as well as a method of making the same, are disclosed. An electrically conductive etch stop layer is formed over a first electrically conductive layer. An electrically conductive diffusion barrier layer is then formed over the electrically conductive etch stop layer, followed by the formation of an insulator layer over the electrically conductive diffusion barrier layer. Next, a patterned photoresist is formed over left and right regions of the insulator layer so as to expose a central region of the insulator layer. Utilizing an etching process with the patterned photoresist in place, insulator materials of the insulator layer in the central region are removed to form a via which exposes electrically conductive materials in the central region. Finally, a second electrically conductive layer is formed within the via over the electrically conductive materials in the central region.

Abstract: A current perpendicular to plane (CPP) sensor having a sensor stack lead layer that is resistant to corrosion. The sensor includes a sensor stack having a capping layer at its top. A lead layer constructed of a non-corroding material such as Ru, Rh, Au or some similar material is formed over the capping layer. A magnetic shield material such a NiFe can then be deposited over the lead layer. The non-corroding lead material prevents the cap layer from corroding, preventing corrosion from causing parasitic resistance in the area in and around the lead and capping layers, thereby increasing sensor performance and reliability.

Abstract: Methods for use in forming current-perpendicular-to-the-planes (CPP) type sensors, including CPP giant magnetoresistance (GMR) type and CPP magnetic tunnel junction (MTJ) type sensors are disclosed. In one particular example, a plurality of CPP type sensor layers are formed over a wafer and a mask without undercuts is formed over the plurality of CPP type sensor layers in a central region. With the mask without undercuts in place, an ion milling process is started to remove CPP type sensor layer materials left exposed by the mask without undercuts in end regions which surround the central region. The ion milling process is stopped at or near a spacer layer of the CPP type sensor layers. Insulator materials are then deposited in the end regions where the CPP type sensor layer materials were removed, followed by hard bias materials over the insulator materials.

Abstract: A dual spin valve giant magnetoresistance (GMR) sensor having two spin valves with the second spin valve being self-biased is disclosed herein. According to the present invention a dual spin valve system is disclosed wherein the first of the two spin valves in the dual spin valve element is pinned through exchange coupling, i.e., a first anti-ferromagnetic pinning layer and a first ferromagnetic pinned layer structure are exchange coupled for pinning the first magnetic moment of the first ferromagnetic pinned layer structure in a first direction. The second of the two spin valves in the dual spin valve system is self-pinned. The self-pinned spin valve does not use any anti-ferromagnetic layers to pin the magnetization of the pinned layers.

Abstract: A magnetoresistive sensor having a hard bias structure having increased coercivity and squareness. The structure also allows the use of a thinner seed layer, which results in improved biasing by decreasing the spacing between the hard magnetic bias layer and the free layer of the sensor. The hard bias structure can be deposited over either a crystalline structure or over an amorphous material. The hard bias structure includes a hard bias material comprising CoPt deposited over a seed layer including a layer of NiTa and a layer of CrMo.

Abstract: A magnetoresistive sensor having a novel seed layer that allows a bias layer formed there over to have exceptional hard magnetic properties when deposited over a crystalline structure such as an AFM layer of in a partial mill sensor design. The seed layer structure may be a CrMo/Si/CrMo sandwich or may also be a CrMo/Si/Cr sandwich and interrupts the epitaxial growth of an underlying crystalline structure, allowing a hard magnetic material formed over the seed layer to have a desired grain structure that is different from that of the underlying crystalline layer.

Abstract: A magnetoresistive sensor having hard bias layers constructed of CoPtCrB, which high coercivity when deposited over crystalline materials such as an AFM layer or other sensor material. The bias layer material exhibits high coercivity and high moment even when deposited over a crystalline structure such as that of an underlying sensor material by not assuming the crystalline structure of the underlying crystalline layer. The bias layer material is especially beneficial for use in a partial mill sensor design wherein a portion of the sensor layers extends beyond the active area of the sensor and the bias layer must be deposited on the extended portion of sensor material.

Abstract: A method is disclosed for fabricating a read head for a magnetic disk drive having a read head sensor and a hard bias layer, where the read head has a shaped junction between the read head sensor and the hard bias layer. The method includes providing a layered wafer stack to be shaped. A single- or multi-layered photoresist mask having no undercut is deposited upon the layered wafer stack to be shaped. The layered wafer stack is shaped by the output of a milling source, where the shaping includes partial milling to within a partial milling range to form a shaped junction. A hard bias layer is then deposited which is in contact with the shaped junction of the wafer stack. A read head and a magnetic hard disk drive having a read head layer stack which has been partially milled are also disclosed.

Abstract: A high magnetization, high resistivity, low corrosion and near zero magnetostriction soft adjacent layer (SAL) is provided for a magnetoresistive (MR) sensor of a read head. The MR sensor may either be an anisotropic MR (AMR) sensor or a spin valve sensor. In both sensors the SAL is CoHfNb or CoHfNbFe. The Hf is added to reduce corrosion and the Hf and Nb are balanced to provide near zero magnetostriction. The addition of Fe is an enhancer for reducing negative magnetostriction without diluting the magnetism of the alloy. Since CoHfNb has significantly higher magnetization than NiFeCr the SAL layer of CoHfNb can be thinner than the SAL of NiFeCr which results in a significantly higher resistance SAL. The higher resistance SAL equates to less shunting of the sense current through the SAL and better signal performance of the MR read head.

Abstract: Methods of making a read head with improved contiguous junctions are described. After sensor layer materials are deposited over a substrate, a lift-off mask is formed over the sensor layer materials in a central region which is surrounded by end regions. Ion milling is performed with use of the lift-off mask such that the sensor layer materials in the end regions are removed and those in the central region remain to form a read sensor. A high-angle ion mill (e.g. between 45–80 degrees) is then performed to remove redeposited material from side walls of the lift-off mask. Next, a reactive ion etch (RIE) is used to reduce the thickness and the width of the lift-off mask and to remove capping layer materials from the top edges of the read sensor. With the reduced-size lift-off mask in place, hard bias and lead layers are deposited adjacent the read sensor as well as over the mask.