Abstract: It is very difficult to produce a negative wall angle from either negative or positive-tone chemically amplified resists, especially by e-beam lithography. This problem has now been overcome by first forming a photoresist pedestal in the conventional way, followed by flood exposing with electrons. Then, a second development treatment is given. This results in removal of additional material from the sidewalls, said removal being greatest at the substrate and least at the pedestal's top surface, resulting in negatively sloping sidewalls. Application of this method to a process for forming a pole tip for a vertical magnetic writer is also discussed.

Abstract: The problem of increased edge sensitivity associated with the reduction of the spacing between bias magnets in a CPP head has been solved by limiting the width of the bias cancellation layer and by adding an extra layer of insulation to ensure that current through the device flows only through its central area, thereby minimizing its edge reading sensitivity.

Abstract: The problem of increased edge sensitivity associated with the reduction of the spacing between bias magnets in a CPP head has been solved by limiting the width of the bias cancellation layer and by adding an extra layer of insulation to ensure that current through the device flows only through its central area, thereby minimizing its edge reading sensitivity.

Abstract: Currently, in a process of manufacturing a top spin valve structure, the shield-to-shield separation of a spin valve head cannot be below about 800 ?, mainly due to sensor-to-lead shorting problems. This problem has now been overcome by inserting a high permeability, high resistivity, thin film shield on the top or bottom (or both) sides of the spin valve sensor. A permeability greater than about 500 is required together with a resistivity about 5 times greater than that of the free layer and an MrT value for the thin film shield that is 4 times greater than that of the free layer.

Abstract: A “toggling” type of magnetic random access memory (MRAM) has memory stacks arranged in the X-Y plane on the MRAM substrate with each memory stack having a plurality of toggle memory cells stacked along the Z axis. Each stack is located at an intersection region between the two orthogonal write lines. The cells are stacked in pairs, with the cells in each pair having their easy axes of magnetization aligned substantially parallel to one another and nonparallel with the X and Y axes. The cells in each pair have their free layers magnetically biased in opposite directions. Because the free layer of each cell in a pair is biased in a direction opposite to the bias direction of the free layer of the other cell, one cell in a pair can be toggle written without toggle writing the other cell in the pair. The bias fields on the free layers reduces the required switching field for each cell, which results in less write current and a lower-power toggling MRAM.

Abstract: Conventional liftoff processes used to define track width in magnetic read heads can produce an uneven etch-depth of dielectric materials around the sensor and cause shorting to the overlay top lead layer. This problem has been overcome by printing the images of track width and stripe height onto an intermediate layer to form a hard mask. Through this hard mask, the GMR stack can be selectively etched and then back-filled with a high-resistivity material by using newly developed electroless plating processes.

Abstract: The problem of increased edge sensitivity associated with the reduction of the spacing between bias magnets in a CPP head has been solved by limiting the width of the bias cancellation layer and by adding an extra layer of insulation to ensure that current through the device flows only through its central area, thereby minimizing its edge reading sensitivity.

Abstract: It is very difficult to produce a negative wall angle from either negative or positive-tone chemically amplified resists, especially by e-beam lithography. This problem has now been overcome by first forming a photoresist pedestal in the conventional way, followed by flood exposing with electrons. Then, a second development treatment is given. This results in removal of additional material from the sidewalls, said removal being greatest at the substrate and least at the pedestal's top surface, resulting in negatively sloping sidewalls. Application of this method to a process for forming a pole tip for a vertical magnetic writer is also discussed.

Abstract: A method for fabricating a current-perpendicular-to-plane (CPP) giant magnetoresistive (GMR) sensor of the synthetic spin valve type is provided, the method including an electron-beam lithographic process employing both primary and secondary electron absorption and first and second self-aligned lift-off processes for patterning the capped ferromagnetic free layer and the conducting, non-magnetic spacer layer. The sensor so fabricated has reduced resistance and increased sensitivity.

Abstract: A major problem in Lead Overlay design for GMR structures is that the magnetic read track width is wider than the physical read track width. This is due to high interfacial resistance between the leads and the GMR layer which is an unavoidable side effect of prior art methods. The present invention uses electroplating preceded by a wet etch to fabricate the leads. This approach requires only a thin protection layer over the GMR layer to ensure that interface resistance is minimal. Using wet surface cleaning avoids sputtering defects and plating is compatible with this so the cleaned surface is preserved Only a single lithography step is needed to define the track since there is no re-deposition involved.

Abstract: A magnetic random access memory (MRAM) has memory stacks arranged in the X-Y plane on the MRAM substrate, with each memory stack having two memory cells stacked along the Z axis and each memory cell having an associated biasing layer. Each biasing layer reduces the switching field of its associated cell by applying a biasing field along the hard-axis of magnetization of the free layer of its associated cell. The free layers in the two cells in each stack have their in-plane easy axes of magnetization aligned parallel to one another. Each biasing layer has its in-plane magnetization direction oriented perpendicular to the easy axis of magnetization (and thus parallel to the hard axis) of the free layer in its associated cell. The hard-axis biasing fields generated by the two biasing layers are in opposite directions.

Abstract: Currently, the shield-to-shield separation of a spin valve head cannot be below about 800 ?, mainly due to sensor-to-lead shorting problems. This problem has now been overcome by a manufacturing method that includes inserting a high permeability, high resistivity, thin film shield on the top or bottom (or both) sides of the spin valve sensor. A permeability greater than about 500 is required together with a resistivity about 5 times greater than that of the free layer and an MrT value for the thin film shield that is 4 times greater than that of the free layer.

Abstract: Currently, the shield-to-shield separation of a spin valve head cannot be below about 800 ?, mainly due to sensor-to-lead shorting problems. This problem has now been overcome by inserting a high permeability, high resistivity, thin film shield on the top or bottom (or both) sides of the spin valve sensor. A permeability greater than about 500 is required together with a resistivity about 5 times greater than that of the free layer and an MrT value for the thin film shield that is 4 times greater than that of the free layer. Five embodiments of the invention are described.

Abstract: Currently, the shield-to-shield separation of a spin valve head cannot be below about 800 ?, mainly due to sensor-to-lead shorting problems. This problem has now been overcome by inserting a high permeability, high resistivity, thin film shield on the top or bottom (or both) sides of the spin valve sensor. A permeability greater than about 500 is required together with a resistivity about 5 times greater than that of the free layer and an MrT value for the thin film shield that is 4 times greater than that of the free layer. Five embodiments of the invention are described.

Abstract: A merged read/write magnetic recording head comprises a low magnetic moment first magnetic shield layer over a substrate. A read gap layer with a magnetoresistive head is formed over the first shield layer. A shared pole comprises a low magnetic moment second magnetic shield layer plated on a sputtered seed PLM layer over the read gap layer, a non-magnetic layer plated over the PLM layer and a HMM lower pole layer plated over the second magnetic shield layer. A write gap layer is formed over the first high magnetic moment pole layer of the shared pole. An upper pole comprises a high magnetic moment pole layer over the write gap layer.

Abstract: A major problem in Lead Overlay design for GMR structures is that the magnetic read track width is wider than the physical read track width. This is due to high interfacial resistance between the leads and the GMR layer which is an unavoidable side effect of prior art methods. The present invention uses electroplating preceded by a wet etch to fabricate the leads. This approach requires only a thin protection layer over the GMR layer to ensure that interface resistance is minimal. Using wet surface cleaning avoids sputtering defects and plating is compatible with this so the cleaned surface is preserved Only a single lithography step is needed to define the track since there is no re-deposition involved.

Abstract: Currently, the shield-to-shield separation of a spin valve head cannot be below about 800 ?, mainly due to sensor-to-lead shorting problems. This problem has now been overcome by inserting a high permeability, high resistivity, thin film shield on the top or bottom (or both) sides of the spin valve sensor. A permeability greater than about 500 is required together with a resistivity about 5 times greater than that of the free layer and an MrT value for the thin film shield that is 4 times greater than that of the free layer. Five embodiments of the invention are described.

Abstract: A method for forming a bi-layer lift-off mask, including a hardened photoresistive stencil layer on a PMGI layer, for use in fabricating GMR read-head sensors with trackwidths of less than 0.1 microns and TMJ MRAM devices of similar critical dimensions. The stencil portion of the mask includes a narrow portion with sharply defined edge and corners which are formed, without rounding or extreme undercut, by a photolithographic process which includes the formation, in a first development process, of auxiliary pattern pieces over the corners of the stencil and a subsequent oxidation in ozone for removing those auxiliary pattern pieces and obtaining sharply defined edge and corners and a controlled dissolution of the PMGI layer.

Abstract: Increasing the output signal from CPP GMR devices by increasing the read current has not previously been considered an option because it would make the device run too hot. This problem has been overcome by using, for the upper and lower leads, materials that differ significantly in their thermoelectric powers. Thus, when DC is passed through the device, from ? to + TEP leads, hot and cold junctions are formed and heat is transferred from the micro-device into the leads, resulting in a net local cooling of the device which enables it to operate at higher power. For a GMR device, this translates to a larger output voltage, making it easier, more sensitive, and more reliable to use.

Abstract: A major problem in Lead Overlay design for GMR structures is that the magnetic read track width is wider than the physical read track width. This is due to high interfacial resistance between the leads and the GMR layer which is an unavoidable side effect of prior art methods. The present invention uses electroplating preceded by a wet etch to fabricate the leads. This approach requires only a thin protection layer over the GMR layer to ensure that interface resistance is minimal. Using wet surface cleaning avoids sputtering defects and plating is compatible with this so the cleaned surface is preserved Only a single lithography step is needed to define the track since there is no re-deposition involved.