Abstract: The GMR read head includes a GMR read sensor and a longitudinal bias (LB) stack in a read region, and the GMR read sensor, the LB stack and a first conductor layer in two overlay regions. In its fabrication process, the GMR read sensor, the LB stack and the first conductor layer are sequentially deposited on a bottom gap layer. A monolayer photoresist is deposited, exposed and developed in order to open a read trench region for the definition of a read width, and RIE is then applied to remove the first conductor layer in the read trench region. After liftoff of the monolayer photoresist, bilayer photoresists are deposited, exposed and developed in order to mask the read and overlay regions, and a second conductor layer is deposited in two unmasked side regions. As a result, side reading is eliminated and a read width is sharply defined by RIE.

Abstract: A self-stabilized spin valve (SV) sensor in which a layer of high-resistance hard magnetic (HM) material is deposited under or over a SV stack to longitudinally bias the free layer by magnetostatic coupling therewith.

Abstract: A read head, which has a head surface facing a moving magnetic medium, includes a read sensor that has first and second side top surface portions and a central top surface portion located between the first and second side top surface portions. First and second overlaying lead layers interface the first and second side top surface portions. First and second hard bias and tapered lead layers interface the first and second overlaying lead layers. A central top surface portion of the read sensor has a width that defines a track width of the read sensor. A method of making the read head includes ion-milling a partially oxidized portion of a cap layer and, after depositing the aforementioned first and second hard bias and tapered lead layers, preferentially reactive ion etching (RIE) the overlaying lead layer not covered by the first and second hard bias and tapered lead layers, so as to define the central top surface portion of the read sensor.

Abstract: Disclosed is a spin-valve sensor employing one or more in-situ oxidized films as cap and/or gap layers in order to achieve an increased GMR coefficient and improved thermal stability. A fabrication method comprises depositing multilayer metallic films on a wafer in ion-beam and DC-magnetron sputtering modules of a sputtering system, and then transferring the wafer in a vacuum to an oxidation module where in-situ oxidation is conducted. When the method is used to form a cap layer, the cap layer may only be partially oxidized. A magnetic-field annealing may be subsequently conducted without the substantial occurrence of interface mixing and oxygen diffusion during the anneal process. The resulting spin-valve sensor exhibits an increased GMR coefficient, possibly due to induced specular scattering of conduction electrons and improved thermal stability mainly due to the protection of an underlying sensing layer from interface mixing and oxygen diffusion during the annealing process.

Abstract: A current-perpendicular-to-plane (CPP) spin valve (SV) sensor and fabrication method with a contiguous junction type geometry that increases sensor resistance by up to two orders of magnitude over conventional CPP GMR geometry for a particular track read-width. The superior CPP GMR coefficient (&dgr;r/R) is implemented at an increased sensor resistance by using two small self-aligned SV stacks disposed with the sense current flowing perpendicular thereto when also flowing parallel to the free layer deposition plane. With the CPP geometry of this invention, thicker conductive spacer layers may be used without unacceptable sense current shunting, so the two self-aligned SV stacks may be completed following the free-layer track-mill step. The two SV stacks may be connected in parallel or back-to-back in series to provide different sense voltages.

Abstract: A magnetoresistive sensor having a well defined track width and method of manufacture thereof.

Abstract: A giant magnetoresistance (GMR) magnetic head that includes a GMR read sensor with a stitched longitudinal bias (LB) stack. The GMR read sensor includes seed, pinning, pinned, spacer, sense and cap layers in a read region, and its seed and pinning layers are extended into two side regions. The LB stack is fabricated on the pinning layer in the two side regions and includes separation, seed and LB layers. The separation layer, preferably made of an amorphous film, separates the pinning layer from the seed and LB layers and thereby prevents unwanted crystalline effects of the pinning layer. Monolayer photoresist patterning and chemical mechanical polishing may be incorporated into the fabrication process of the GMR head to attain uniform thicknesses of the separation, seed and LB layers, and to align the midplane of the LB layer at the same horizontal level as the midplane of the sense layer.

Abstract: A method is described comprising forming an insulating polycrystalline seed layer in a first chamber by reactively pulsed DC magnetron sputtering, then forming an insulating amorphous-like seed layer in a second chamber by reactively pulsed DC magnetron sputtering, then forming a conducting seed layer and a ferromagnetic free layer in a third chamber by ion beam sputtering, and then forming the remainder of a spin valve sensor through the antiferromagnetic layer in a fourth chamber by DC magnetron sputtering.

Abstract: A current-perpendicular-to-plane (CPP) read head with an amorphous magnetic bottom shield layer and an amorphous nonmagnetic bottom lead gap layer is disclosed. The amorphous magnetic bottom shield layer and amorphous nonmagnetic bottom lead layer provide a planar surface for the CPP read head deposited thereon to exhibit a low ferromagnetic coupling field and a high giant (or tunneling) magnetoresistance coefficient. The amorphous magnetic bottom shield layer is preferably formed of an Fe-based or Co-based film. The amorphous nonmagnetic bottom lead layer is preferable formed of a W-based or Ni-based film.

Abstract: The GMR read head includes a GMR read sensor and a longitudinal bias (LB) stack in a read region, and the GMR read sensor, the LB stack and a first conductor layer in two overlay regions. In its fabrication process, the GMR read sensor, the LB stack and the first conductor layer are sequentially deposited on a bottom gap layer. A monolayer photoresist is deposited, exposed and developed in order to open a read trench region for the definition of a read width, and RIE is then applied to remove the first conductor layer in the read trench region. After liftoff of the monolayer photoresist, bilayer photoresists are deposited, exposed and developed in order to mask the read and overlay regions, and a second conductor layer is deposited in two unmasked side regions. As a result, side reading is eliminated and a read width is sharply defined by RE.

Abstract: A dual magnetic tunnel junction (MTJ) sensor is provided with a longitudinal bias stack sandwiched between a first MTJ stack and a second MTJ stack. The longitudinal bias stack comprises an antiferromagnetic (AFM) layer sandwiched between first and second ferromagnetic layers. The first and second MTJ stacks comprise antiparallel (AP)-pinned layers pinned by AFM layers made of an AFM material having a higher blocking temperature than the AFM material of the bias stack allowing the AP-pinned layers to be pinned in a transverse direction and the bias stack to be pinned in a longitudinal direction. The demagnetizing fields of the two AP-pinned layers cancel each other and the bias stack provides flux closures for the sense layers of the first and second MTJ stacks.

Abstract: A dual spin valve (SV) sensor is provided with a longitudinal bias stack sandwiched between a first SV stack and a second SV stack. The longitudinal bias stack comprises an antiferromagnetic (AFM) layer sandwiched between first and second ferromagnetic layers. The first and second SV stacks comprise antiparallel (AP)-pinned layers pinned by AFM layers made of an AFM material having a higher blocking temperature than the AFM material of the bias stack allowing the AP-pinned layers to be pinned in a transverse direction and the bias stack to be pinned in a longitudinal direction. The demagnetizing fields of the two AP-pinned layers cancel each other and the bias stack provides flux closures for the sense layers of the first and second SV stacks.

Abstract: A read head is provided having having ultrathin read gap layers with improved insulative properties between a magnetoresistive sensor and ferromagnetic shield layers. The read head comprises a magnetoresistive sensor with first and second shield cap layers made of high resistivity permeable magnetic material formed between the first and second ferromagnetic shields and the first and second insulative read gap layers, respectively. The shield cap layers made of Fe—Hf—Ox material, or alternatively, the Mn—Zn ferrite material provide highly resistive or insulating soft ferromagnetic layers which add to the electrically insulative read gap layers to provide increased electrical insulation of the spin valve sensor from the metallic ferromagnetic shields while not adding to the magnetic read gap of the read head.

Abstract: A method is described comprising forming an insulating polycrystalline seed layer in a first chamber by reactively pulsed DC magnetron sputtering, then forming an insulating amorphous-like seed layer in a second chamber by reactively pulsed DC magnetron sputtering, then forming a conducting seed layer and a ferromagnetic free layer in a third chamber by ion beam sputtering, and then forming the remainder of a spin valve sensor through the antiferromagnetic layer in a fourth chamber by DC magnetron sputtering.

Abstract: A spin-valve sensor with pinning layers comprising multiple antiferromagnetic films is disclosed. The multiple antiferromagnetic films are preferably selected from the same Mn-based (Ni—Mn or Pt—Mn) alloy system. The Mn content of the antiferromagnetic film in contact with the reference layer of the spin-valve sensor is selected in order to maximize its exchange coupling to the reference layer, thereby providing a high unidirectional anisotropy field for proper sensor operation. The Mn content of the other antiferromagnetic films not in contact with the reference layer of the spin-valve sensor is reduced in order to maximize the thermal stability and corrosion resistance of the spin-valve sensor for robust sensor operation at high temperatures in disk drive environments.

Abstract: Disclosed is a system and method for forming a current-perpendicular-to-plane (CPP) spin-valve sensor with one or more metallic oxide barrier layers in order to provide a low junction resistance and a high GMR coefficient. In disclosed embodiments, the metallic oxide barrier layers are formed with oxygen-doping/in-situ oxidation processes comprising depositing a metallic film in a first mixture of argon and oxygen gases and subsequent in-situ oxidization in a second mixture of argon and oxygen gases. The exposure to oxygen may be conducted at a low partial oxygen pressure and at a moderate temperature. Smaller, more sensitive CPP spin-valve sensors may be formed through the use of the oxygen-doping/in-situ oxidization processes of the present invention, thus allowing for greater densities of disk drive systems.

Abstract: A magnetoresistance sensor structure is formed of a magnetoresistance sensor having a transverse biasing stack including a transverse pinning layer made of a transverse-pinning-layer antiferromagnetic material, and a transverse pinned layer structure overlying the transverse pinning layer, a spacer layer overlying the transverse pinned layer structure, a sensing stack overlying the spacer layer, and a decoupling layer overlying the sensing stack. A longitudinal biasing stack overlies the magnetoresistance sensor and includes a longitudinal pinned layer, and a longitudinal pinning layer overlying the longitudinal pinned layer and made of a longitudinal-pinning-layer antiferromagnetic material. The transverse-pinning-layer antiferromagnetic material and the longitudinal-pinning-layer antiferromagnetic material are preferably Pt—Mn or Ni—Mn.

Abstract: A method is described comprising forming an insulating polycrystalline seed layer in a first chamber by reactively pulsed DC magnetron sputtering, then forming an insulating amorphous-like seed layer in a second chamber by reactively pulsed DC magnetron sputtering, then forming a conducting seed layer and a ferromagnetic free layer in a third chamber by ion beam sputtering, and then forming the remainder of a spin valve sensor through the antiferromagnetic layer in a fourth chamber by DC magnetron sputtering.

Abstract: Disclosed is a spin-valve sensor employing one or more in-situ oxidized films as cap and/or gap layers in order to achieve an increased GMR coefficient and improved thermal stability. A fabrication method comprises depositing multilayer metallic films on a wafer in ion-beam and DC-magnetron sputtering modules of a sputtering system, and then transferring the wafer in a vacuum to an oxidation module where in-situ oxidation is conducted. When the method is used to form a cap layer, the cap layer may only be partially oxidized. A magnetic-field annealing may be subsequently conducted without the substantial occurrence of interface mixing and oxygen diffusion during the anneal process. The resulting spin-valve sensor exhibits an increased GMR coefficient, possibly due to induced specular scattering of conduction electrons and improved thermal stability mainly due to the protection of an underlying sensing layer from interface mixing and oxygen diffusion during the annealing process.

Abstract: Disclosed is a spin-valve sensor disposed between first and second gap layers and formed of one or more in-situ oxidized films. The improved spin valve sensor helps eliminate electrical shorting between the spin-valve sensor and shield layers. A fabrication method of the gap layers comprises repeatedly depositing a metallic films on a wafer in a DC-magnetron sputtering module of a sputtering system, and then transferring the wafer in a vacuum to an oxidation module where in-situ oxidation is conducted. This deposition/in-situ oxidation process is repeated until a designed thicknesses of gap layers is attained. Smaller, more sensitive spin-valve sensors may be sandwiched between thinner gap layers formed of in-situ oxidized films, thus allowing for greater recording data densities in disk drive systems.