Abstract: A magnetic head includes a seed layer structure comprising Ta and NiFeCr seed layers; an antiparallel (AP) pinned layer structure formed above the NiFeCr seed layer; a free layer positioned above the AP pinned layer structure; and a layer of metal oxide positioned between the free layer and the AP pinned layer structure. A magnetic head in another embodiment includes a seed layer structure comprising Al2O3, Ta, and NiFeCr seed layers, wherein a thickness of the NiFeCr seed layer is less than about a thickness of at least one of the Al2O3 and Ta seed layers; an antiparallel (AP) pinned layer structure formed above the NiFeCr seed layer; and a free layer positioned above the AP pinned layer structure. In another embodiment, a thickness of the NiFeCr seed layer is greater than about a thickness of at least one of the Al2O3 and Ta seed layers.

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 magnetic head with improved hard magnet properties includes a sensor stack structure and a multi-layered seed layer structure formed over crystalline materials of the sensor stack structure. The multi-layered structure has a first layer including chromium-molybdenum (CrMo); a second layer including nitrogenated nickel-tantalum (NiTa+N); and a third layer including chromium-molybdenum (CrMo). A hard bias layer formed over the multi-layered structure is preferably cobalt-platinum-chromium (CoPtCr). Methods of making the magnetic head are also described.

Abstract: A read head and a magnetic hard disk drive having a read head layer stack which has been partially milled to within a partial milling range to form a shaped junction and a hard bias layer which is in contact with the shaped junction of the wafer stack.

Abstract: A method for forming a MgO barrier layer in a tunnel junction magnetoresistive sensor (TMR). The MgO barrier layer is deposited by an ion beam deposition process that results in a MgO barrier layer having exceptional, uniform properties and a well controlled oxygen content. The ion beam deposition of the barrier layer includes placing a wafer into an ion deposition chamber and placing Mg target into the chamber. An ion beam from an ion beam gun is directed at the target thereby dislodging Mg atoms from the target for deposition onto the wafer. Oxygen is introduced into the chamber by one or both of pumping molecular oxygen (O2) into the chamber and/or introducing oxygen ions into the chamber from a second ion beam gun. The use of ion beam deposition avoids oxygen poisoning of the Mg target, such as would occur using a more conventional plasma vapor deposition technique.

Abstract: A magnetoresistive sensor having magnetically anisotropic bias layers for biasing the free layer of the sensor. The sensor includes a sensor stack with a pinned layer structure and a free layer structure and having first and second sides. Hard bias structures for biasing the magnetization of the free layer are formed at either side of the sensor stack, and each of the hard bias structure includes a hard magnetic layer that has a magnetic anisotropy to enhance the stability of the biasing. The hard bias structure can include a Cr under-layer having a surface that has been treated by a low power angled ion milling to form it with an anisotropic surface texture. A layer of Cr—Mo alloy is formed over the Cr under-layer and the hard magnetic material layer is formed over the Cr—Mo alloy layer. The anisotropic surface texture of the Cr layer induces an aligned crystalline structure in the hard magnetic layer that causes the hard magnetic layer to have a magnetic anisotropy.

Abstract: A tunnel junction magnetoresistive sensor having improved TMR performance (dR/R) and improved area resistance. The sensor includes a barrier layer sandwiched between a magnetic pinned layer structure and a magnetic free layer structure. The barrier layer includes a thin layer of Mg and a layer of MgOx. The barrier layer could also include a second thin layer of Mg such that the MgOx layer is sandwiched between the first and second Mg layers.

Abstract: A magnetoresistive sensor having magnetically anisotropic bias layers for biasing the free layer of the sensor. The sensor includes a sensor stack with a pinned layer structure and a free layer structure and having first and second sides. Hard bias structures for biasing the magnetization of the free layer are formed at either side of the sensor stack, and each of the hard bias structure includes a hard magnetic layer that has a magnetic anisotropy to enhance the stability of the biasing. The hard bias layer is formed on a buffer layer and a seed layer, the seed layer being sandwiched between the buffer layer and the hard bias layer. The buffer layer has an anisotropic surface texture that promotes the magnetic anisotropy in the hard bias layer. The buffer layer can be CrMo or Ru or can be a bi-layer including a layer of CrMo with a layer of Ru over the CrMo. The seed layer can be constructed of a material having a BCC structure and is preferably constructed of CrMo.

Abstract: A magnetic head is disclosed having a CPP read sensor including a seed layer of NiFeCr, a self-pinned structure, a spacer layer, at least one free layer, and an upper capping layer. A lower capping layer of conductive material is also preferred. An alternate embodiment includes a read sensor having an in-stack biasing structure.

Abstract: A lead overlay design of a magnetic sensor is described with sensor and free layer dimensions such that the free layer is stabilized by the large demagnetization field due to the shape anisotropy. In one embodiment the giant magnetoresistive (GMR) effect under the leads is destroyed by removing the antiferromagnetic (AFM) and pinned layers above the free layer. The overlaid lead pads are deposited on the exposed spacer layer at the sides of the mask that defines the active region. In other embodiment a layer of electrically insulating material is deposited over the sensor to encapsulate it and thereby insulate it from contact with the hardbias structures. Various embodiments with self-aligned leads are also described. In a variation of the encapsulation embodiment, the insulating material is also deposited under the lead pads so the electrical current is channeled through the active region of the sensor and sidewall deposited lead pads.

Abstract: A magnetoresistive sensor having a pinned layer that extends beyond the stripe height defined by the free layer of the sensor. The extended pinned layer has a strong shape induced anisotropy that maintains pinning of the pinned layer moment. The extended portion of the pinned layer has sides beyond the stripe height that are perfectly aligned with the sides of the sensor within the stripe height. This perfect alignment is made possible by a manufacturing method that uses a mask structure for more than one manufacturing phase, eliminating the need for multiple mask alignments.

Abstract: A method 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.

Abstract: A magnetoresistive sensor having a shape enhanced pinning and a flux guide structure. The sensor includes a sensor stack with a pinned layer, spacer layer and pinned layer. First and second hard bias layers and lead layers extend from the sides of the sensor stack. The hard bias layers and leads have a stripe height that is smaller than the stripe height of the free layer, resulting in a free layer that extends beyond the back edge of the lead and hard bias layer. This portion of the free layer that extends beyond the back edge of the leads and hard bias layers provides a back flux guide. Similarly, the sensor may have a free layer that extends beyond the front edge of the lead and hard bias layers to provide a front flux guide. The pinned layer extends significantly beyond the back edge of the free layer, providing the pinned layer with a strong shape enhanced magnetic anisotropy.

Abstract: A magnetic head having an improved PtMn layer formed by ion beam deposition, an antiparallel (AP) pinned layer structure formed above the PtMn layer, and a free layer formed above the AP pinned layer structure. The spin valve structure provides improved soft magnetic properties of the free layer as well as increases the dR/R of spin valve structures in which implemented.

Abstract: A magnetoresistive sensor having a pinned layer that extends beyond the free layer in the stripe height direction for improved shape enhanced pinning. The sensor includes hard bias layers and leads that extend in the stripe height direction beyond the stripe height of the free layer, providing increased conductive material for improved conduction of sense current to the sensor. The hard bias layers contact the sensor stack in the region between the ABS and the stripe height of the free layer, but are electrically insulated from the pinned layer in regions beyond the stripe height of the free layer by a layer of conformally deposited non-magnetic, electrically insulating material such as alumina.

Abstract: A current perpendicular to plane (CPP) magnetoresistive sensor having a current path defined by first and second overlying insulation layers between which an electrically conductive lead makes content with a surface of the sensor stack. The current path being narrower than the width of the sensor stack allows the outer edges of the sensor stack to be moved outside of the active area of the sensor. This results in a sensor that is unaffected by damage at outer edges of the sensor layers. The sensor stack includes a free layer that is biased by direct exchange coupling with a layer of antiferromagnetic material (AFM layer). The strength of the exchange field can be controlled by adding Cr to the AFM material to ensure that the exchange field is sufficiently weak to avoid pinning the free 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 read head for a disk drive and a method of fabricating the read head with overlaid lead pads that contact the top surface of the sensor between the hardbias structures to define the electrically active region of the sensor are described. The invention deposits the GMR and lead layers before milling away the unwanted material. A photoresist mask with a hole defining the active area of the sensor is preferably patterned over a layer of DLC that is formed into a mask. A selected portion of the exposed lead material is then removed using the DLC as a mask defining the active region of the sensor. A photoresist mask pad is patterned to define the full sensor width. The excess sensor and lead material exposed around the mask is milled away. The layers for the hardbias structure are deposited.

Abstract: A method for forming a magnetic head having an improved PtMn layer, including forming a PtMn layer by ion beam deposition, forming an antiparallel (AP) pinned layer structure above the PtMn layer, and forming a free layer above the AP pinned layer structure. The method provides a spin valve structure having improved soft magnetic properties of the free layer as well as increases the dR/R of spin valve structures in which implemented.

Abstract: A magnetic head having an improved read head structure. The read head includes a free magnetic layer with hard bias elements disposed proximate its ends, where the hard bias elements include an improved hard bias magnetic grain structure. This is accomplished by fabricating the hard bias element as a bilayer structure having a first hard bias sublayer, a nonmagnetic midlayer and a second hard bias sublayer. The midlayer is preferably composed of a nonmagnetic material such as chromium, and the hard bias sublayers are composed of a magnetic material such as CoPtCr. Each sublayer is formed with its own magnetic grains, and because there are two sublayers, the hard bias element is fabricated with approximately twice the number of magnetic grains as the prior art single layer hard bias element.