Abstract: Methods and apparatus provide magnetoresistance sensors. A tunneling magnetoresistance (TMR) sensor may include configurations that are arranged as a top TMR stack. One of two antiparallel layers of pinned layers within the TMR stack may be subdivided by a spacer layer. Tantalum may form the spacer layer that is inserted in a reference layer, which is one of the pinned layers and is located between a barrier layer and an antiparallel coupling layer that enables antiparallel coupling between the reference layer and a keeper layer of the pinned layers. The barrier layer deposited on a free layer of the TMR stacks separates the pinned layers from the free layer such that TMR effects are detectable with the sensors.

Abstract: A magnetoresistive sensor having an antiparallel coupled pinned layer structure including an AP1 layer and an AP2 layer. The AP2 layer includes two ferromagnetic layers AP2(a) and AP2(b), and a separation layer sandwiched therebetween. The AP2(a) layer is significantly larger than the AP2(b) layer, which results in strong pinning, while the separation layer provides increased TMR and reduced RA.

Abstract: An anti-parallel pinned sensor is provided with a spacer that increases the anti-parallel coupling strength of the sensor. The anti-parallel pinned sensor is a GMR or TMR sensor having a pure ruthenium or ruthenium alloy spacer. The thickness of the spacer is less than 0.8 nm, preferably between 0.1 and 0.6 nm. The spacer is also annealed in a magnetic field that is 1.5 Tesla or higher, and preferably greater than 5 Tesla. This design yields unexpected results by more than tripling the pinning field over that of typical AP-pinned GMR and TMR sensors that utilize ruthenium spacers which are 0.8 nm thick and annealed in a relatively low magnetic field of approximately 1.3 Tesla.

Abstract: A magnetic head of either CIP or CPP configuration is disclosed, having a read sensor with a strongly pinned ferromagnetic layer due to increased electronic exchange with the AFM layer. The read sensor includes a lower seed layer whose material is chosen from a group consisting of Ta, NiFeCr, NiFeCoCr, NiFe, Cu, Ta/NiFeCr, Ta/NiFeCr/NiFe, Ta/Ru and Ta/NiFeCoCr, and an upper seed layer where the upper seed layer material is chosen from a group consisting of Ru, Cu, NiFe, Cu(x)Au(1?x)(x=0.22-0.5) alloys, Ru(x)Cr(1?x)(x=0.1-0.5) alloys, NiFeCr and NiFeCoCr. An AFM layer is formed on the upper seed layer and a ferromagnetic pinned layer is formed on the AFM layer. The exchange coupling energy Jk between the AFM layer and pinned layers exceeds 1.3 erg/cm2. Also disclosed is a method of fabrication of a magnetic head including a read head sensor with a strongly pinned ferromagnetic layer due to increased electronic exchange.

Abstract: A method for fabricating a magnetic head including a spin valve sensor having a sensor layer stack that includes a pinned magnetic layer, a spacer layer formed on the pinned magnetic layer, and a free magnetic layer formed on the spacer layer. In a preferred embodiment the spacer layer is comprised of CuOx. The method includes the plasma smoothing of the upper surface of the pinned magnetic layer prior to depositing the spacer layer, and a preferred plasma gas is a mixture of argon and oxygen.

Abstract: Methods and apparatus provide magnetoresistance sensors. A tunneling magnetoresistance (TMR) sensor may include configurations that are arranged as a top TMR stack. One of two antiparallel layers of pinned layers within the TMR stack may be subdivided by a spacer layer. Tantalum may form the spacer layer that is inserted in a reference layer, which is one of the pinned layers and is located between a barrier layer and an antiparallel coupling layer that enables antiparallel coupling between the reference layer and a keeper layer of the pinned layers. The barrier layer deposited on a free layer of the TMR stacks separates the pinned layers from the free layer such that TMR effects are detectable with the sensors.

Abstract: A magnetoresistive sensor having an antiparallel coupled pinned layer structure including an AP1 layer and an AP2 layer. The AP2 layer includes two ferromagnetic layers AP2(a) and AP2(b), and a separation layer sandwiched therebetween. The AP2(a) layer is significantly larger than the AP2(b) layer, which results in strong pinning, while the separation layer provides increased TMR and reduced RA.

Abstract: A magnetoresistive sensor having a Ta cap layer with nitrogen added in situ during deposition. The nitrogen in the cap layer can be formed by depositing a Ta cap layer in a sputter deposition chamber having a small amount of nitrogen in an Ar atmosphere. The resulting nitrogenated cap layer exhibits reduced specular scattering, which results in improved magnetic performance of the magnetoresistive sensor.

Abstract: An anti-parallel pinned sensor is provided with a spacer that increases the anti-parallel coupling strength of the sensor. The anti-parallel pinned sensor is a GMR or TMR sensor having a pure ruthenium or ruthenium alloy spacer. The thickness of the spacer is less than 0.8 nm, preferably between 0.1 and 0.6 nm. The spacer is also annealed in a magnetic field that is 1.5 Tesla or higher, and preferably greater than 5 Tesla. This design yields unexpected results by more than tripling the pinning field over that of typical AP-pinned GMR and TMR sensors that utilize ruthenium spacers which are 0.8 nm thick and annealed in a relatively low magnetic field of approximately 1.3 Tesla.

Abstract: A magnetic head and magnetic storage system containing such a head, the head including a free layer and a layer of metal oxide substantially epitaxially formed relative to the free layer. Preferably, the layer of metal oxide is a crystalline structure, and is of ZnO.

Abstract: An anti-parallel pinned sensor is provided with a spacer that increases the anti-parallel coupling strength of the sensor. The anti-parallel pinned sensor is a GMR or TMR sensor having a pure ruthenium or ruthenium alloy spacer. The thickness of the spacer is less than 0.8 nm, preferably between 0.1 and 0.6 nm. The spacer is also annealed in a magnetic field that is 1.5 Tesla or higher, and preferably greater than 5 Tesla. This design yields unexpected results by more than tripling the pinning field over that of typical AP-pinned GMR and TMR sensors that utilize ruthenium spacers which are 0.8 nm thick and annealed in a relatively low magnetic field of approximately 1.3 Tesla.

Abstract: A magnetic head of either CIP or CPP configuration is disclosed, having a read sensor with a strongly pinned ferromagnetic layer due to increased electronic exchange with the AFM layer. The read sensor includes a lower seed layer whose material is chosen from a group consisting of Ta, NiFeCr, NiFeCoCr, NiFe, Cu, Ta/NiFeCr, Ta/NiFeCr/NiFe, Ta/Ru and Ta/NiFeCoCr, and an upper seed layer where the upper seed layer material is chosen from a group consisting of Ru, Cu, NiFe, Cu(x)Au(1-x)(x=0.22-0.5) alloys, Ru(x)Cr(1-x)(x=0.1-0.5) alloys, NiFeCr and NiFeCoCr. An AFM layer is formed on the upper seed layer and a ferromagnetic pinned layer is formed on the AFM layer. The exchange coupling energy Jk between the AFM layer and pinned layers exceeds 1.3 erg/cm2. Also disclosed is a method of fabrication of a magnetic head including a read head sensor with a strongly pinned ferromagnetic layer due to increased electronic exchange.

Abstract: A magnetic head having a free layer and an antiparallel (AP) pinned layer structure spaced apart from the free layer. The AP pinned layer structure includes at least two pinned layers having magnetic moments that are self-pinned antiparallel to each other, the pinned layers being separated by an AP coupling layer constructed of a Ru alloy. The use of a Ru alloy coupling layer significantly increases the pinning field of the AP pinned layer structure over a pure Ru spacer.

Abstract: A magnetoresistive sensor having a substrate that has been treated with nitrogen (nitrogenated). The nitrogenated substrate includes an alumina base layer and a thin top layer of crystalline alumina that has had a very small amount of nitrogen deposited on top. The amount of nitrogen deposited on top of the alumina is less than or equal to two monolayer, and is preferably less than on monolayer. The amount of nitrogen deposited on top of the alumina substrate is not enough to constitute a layer of nitrogen, but affects the structure of the alumina to cause the alumina to have a desired crystalline structure and an extremely smooth surface.

Abstract: A magnetoresistive sensor having a substrate that has been treated with nitrogen (nitrogenated). The nitrogenated substrate includes an alumina base layer and a thin top layer of crystalline alumina that has had a very small amount of nitrogen deposited on top. The amount of nitrogen deposited on top of the alumina is less than or equal to two monolayer, and is preferably less than or monolayer. The amount of nitrogen deposited on top of the alumina substrate is not enough to constitute a layer of nitrogen, but affects the structure of the alumina to cause the alumina to have a desired crystalline structure and an extremely smooth surface.

Abstract: A magnetoresistive sensor having a Ta cap layer with nitrogen added in situ during deposition. The nitrogen in the cap layer can be formed by depositing a Ta cap layer in a sputter deposition chamber having a small amount of nitrogen in an Ar atmosphere. The resulting nitrogenated cap layer exhibits reduced specular scattering, which results in improved magnetic performance of the magnetoresistive sensor.

Abstract: A magnetoresistive sensor having a substrate that has been treated with nitrogen (nitrogenated) and having a Ta cap layer with nitrogen added in situ during deposition. The nitrogenated substrate includes an alumina base layer and a thin top layer of crystalline alumina that has had a very small amount of nitrogen deposited on top. The amount of nitrogen deposited on top of the alumina is less than or equal to two monolayer, and is preferably less than on monolayer. The amount of nitrogen deposited on top of the alumina substrate is riot enough to constitute a layer of nitrogen, but affects the structure of the alumina to cause the alumina to have a desired crystalline structure and an extremely smooth surface. The nitrogen in the cap layer can be formed by depositing a Ta cap layer in a sputter deposition chamber having a small amount of nitrogen in an Ar atmosphere.

Abstract: A spin valve (SV) sensor of the self-pinned type includes one or more compressive stress modification layers for reducing the likelihood that the pinning field will flip its direction. The spin valve sensor includes a capping layer formed over a spin valve structure which includes a free layer, an antiparallel (AP) self-pinned layer structure, and a spacer layer in between the free layer and the AP self-pinned layer structure. A compressive stress modification layer is formed above or below the capping layer, adjacent the AP self-pinned layer structure, or both. Preferably, the compressive stress modification layer is made of ruthenium (Ru) or other suitable material.

Abstract: A method for constructing a magnetoresistive sensor using a horizontally disposed superconducting magnetic tool. The superconducting magnetic tool is capable of generating very high magnetic fields for sustained periods of time to effectively set the magnetizations of magnetoresitive sensors having a very high pinning field. The supermagnetic tool has a ceramic tube surrounded by a superconducting coil. The tube has a longitudinal axis that is oriented horizontally, thereby providing numerous important benefits, such as: facilitating manipulation of the sensor containing wafer within the tool; facilitating loading of the wafer into the tool; preventing temperature and field gradients within the wafer during the anneal; and facilitating maintenance and storage of the tool by limiting the height of the tool.

Abstract: A magnetic head having a free layer and an antiparallel (AP) pinned layer structure spaced apart from the free layer. The AP pinned layer structure includes at least two pinned layers having magnetic moments that are self-pinned antiparallel to each other, the pinned layers being separated by an AP coupling layer constructed of a Ru alloy. The use of a Ru alloy coupling layer significantly increases the pinning field of the AP pinned layer structure over a pure Ru spacer.