Abstract: A process is described for fabricating sliders with reduced lapping damage to the hard-bias materials. The stack of layers for the magnetic sensor is deposited on a wafer and patterned into an initial shape. The hard-bias structures are fabricated at the side of the magnetic sensor as in the prior art. In each of the two described embodiments of the invention, the hard-bias material below the ABS is reduced or removed and replaced with a fill material such as alumina. A first embodiment reduces the hard-bias material below the ABS by forming an extended lapping gap along the ABS in both the sensor and hard-bias material. A second embodiment forms a photoresist mask over the sensor and the portion of the hard-bias/lead structures above the ABS and the exposed hard-bias/lead material below the ABS is thinned or completely removed by milling.

Abstract: A method for making a magnetoresistive read head so that the pinned ferromagnetic layer is wider than the stripe height of the free ferromagnetic layer uses ion milling with the ion beam aligned at an angle to the substrate supporting the stack of layers making up the read head. The stack is patterned with photoresist to define a rectangular region with front and back long edges aligned parallel to the read head track width. After ion milling in two opposite directions orthogonal to the front and back long edges, the pinned layer width has an extension. The extension makes the width of the pinned layer greater than the stripe height of the free layer after the substrate and stack of layers are lapped. The length of the extension is determined by the angle between the substrate and the ion beam and the thickness of the photoresist.

Abstract: A method for fabricating a sensor having anti-parallel tab regions. The method includes forming a free layer having tab areas on opposite sides of an active area, forming a first layer of a carbon composition above the active area of the free layer, the first layer of carbon being substantially absent from tab areas of the free area, forming spacer layers above the tab areas of the free layer, the spacer layers being operable to make magnetic moments of ferromagnetic layers on opposite sides thereof antiparallel, forming bias layers above the spacer layers, the bias layers being operative to substantially pin magnetic moments of the tab areas of the free layer, forming second layers of carbon composition above the tab areas of the free layer, and removing the layers of carbon composition and any portions of the layers overlying the layers of carbon composition.

Abstract: A method for constructing a magnetoresistive sensor which eliminates all redeposited material (redep) from the sides of the sensor. The method involves forming a mask over a plurality of sensor layers, and then performing an ion mill at an angle that is nearly normal to the surface of the sensor layers. A second (glancing) ion mill is then performed at a larger angle with respect to the normal. The first ion mill may be 0-30 degrees with respect to normal, whereas the second ion mill can be 50-89 degrees with respect to normal. The first ion mill is performed with a larger bias voltage than the second ion mill. The higher bias voltage of the first ion mill provides a well collimated ion beam to form straight vertical side walls. The lower bias voltage of the second ion mill prevent damage to the sensor layers during the removal of redep from the sides of the sensor.

Abstract: A method for milling a structure. A single- or multi-layer resist having no undercut is added to a surface of a structure to be milled, the surface to be milled defining a plane. A milling process, such as ion milling, is performed. The milling process includes milling the structure at high incidence and milling the structure at razing incidence. The milling process can be performed only once, or repeated multiple times. High incidence can be defined as about 65 to about 90 degrees from the plane of the surface being milled. Razing incidence can be defined as about 0 to about 30 degrees from the plane of the surface being milled.

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.

Abstract: Magnetic sensors are fabricated with an initial length that is slightly longer than their finished length. The sensors are then critically lapped and exposed for target signal output. The final target length of the sensors is obtained by first exposing the sensors to a photolithographic process and then directly lapping the excess length from the sensors. The length of sensor material that is removed is in the range of several nanometers. The target end point during lapping may be ascertained by detecting the change in resistance between the sensor and leads in the lapping tool as the excess material is lapped from the sensor.

Abstract: An in-line lapping guide uses a contiguous resistor in a cavity to separate a lithographically-defined sensor from the in-line lapping guide. As lapping proceeds through the cavity toward the sensor, the resistance across the sensor leads increases to a specific target, thereby indicating proximity to the sensor itself. The contiguous resistor is fabricated electrically in parallel to the sensor and the in-line lapping guide. The total resistance across the sensor leads show resistance change even when lapping through the cavity portion. One method to produce the contiguous resistor is to partial mill the cavity between the sensor and the in-line lapping guide so that a film of metal is left. Total resistance across leads is the parallel resistance of the sensor, the contiguous resistor, and the in-line lapping guide.

Abstract: A method is described which uses a CMP resistant metal layer to replace the upper dielectric layer in the track width definition phase of a TMR or CPP spin valve magnetic head. The metal which is selected to be resistant to the CMP process can be rhodium (Rh), platinum (Pt), chromium (Cr), vanadium (V), etc. The additional CMP resistance of the refill layer structure provides a much larger processing window which results in higher yields. A CPP head according to the invention has a metal layer according to the invention above the hard bias structures on the sides of the sensor which define the track width.

Abstract: A method for providing a liftoff process using a single layer resist and chemical mechanical polishing and sensor formed therewith are disclosed. Chemical mechanical polishing is combined with liftoff using only a single resist layer to allow the removal of leftover fencing on the side of a lifted resist pattern.

Abstract: A magnetic sensor is provided, having two bias layers separated by a decoupling layer to eliminate exchange coupling between the bias layers. The two bias layers may have differing coercivities, such that the biases provided by the bias layers to the free layer are independently adjustable. The grain structures of the two bias layers may be substantially decorrelated by the decoupling layer.

Abstract: A method for fabricating a read head sensor for a magnetic disk drive is presented. The method includes providing a layered wafer stack to be shaped, where the layered wafer stack includes a free layer, a barrier layer and a pinned layer. A single- or multi-layered photoresist mask is formed upon the layered wafer stack to be shaped. A material removal source is provided and used to perform a partial depth material removal within a partial depth material removal range which extends from the free layer to within the pinned layer to a partial depth material removal endpoint. In various embodiments, this depth endpoint lies at or within the barrier layer or within but not through the pinned layer.

Abstract: A method for fabricating magnetic side shields for an MR sensor of a magnetic head. Following the deposition of MR sensor layers, a first DLC layer is deposited. Milling mask layers are then deposited, and outer portions of the milling mask layers are removed such that a remaining central portion of the milling mask layers is formed having straight sidewalls and no undercuts. Outer portions of the sensor layers are then removed such that a relatively thick remaining central portion of the milling mask resides above the remaining sensor layers. A thin electrical insulation layer is deposited, followed by the deposition of magnetic side shields. A second DLC layer is deposited and the remaining mask layers are then removed utilizing a chemical mechanical polishing (CMP) liftoff step. Thereafter, the first DLC layer and the second DLC layer are removed and a second magnetic shield layer is then fabricated thereabove.

Abstract: A method for making a magnetoresistive read head so that the pinned ferromagnetic layer is wider than the stripe height of the free ferromagnetic layer uses ion milling with the ion beam aligned at an angle to the substrate supporting the stack of layers making up the read head. The stack is patterned with photoresist to define a rectangular region with front and back long edges aligned parallel to the read head track width. After ion milling in two opposite directions orthogonal to the front and back long edges, the pinned layer width has an extension. The extension makes the width of the pinned layer greater than the stripe height of the free layer after the substrate and stack of layers are lapped. The length of the extension is determined by the angle between the substrate and the ion beam and the thickness of the photoresist.

Abstract: A method is described which uses a CMP slurry with an abrasive of spherical particles to lift-off photoresist used in the patterning of the sensor for a magnetic transducer. The spherical particles, preferably less than 0.015 microns, are preferably silica, alumina, titania or zirconia with colloidal silica being preferred. An alternative method of fabricating a CPP sensor structure according to the invention deposits a dielectric or CMP resistant metal over the hard bias structure. The CMP-resistant metal is preferably selected from the group consisting of rhodium, chromium, vanadium and platinum. A CMP resistant mask deposited over the dielectric or CMP-resistant metal can include an optional adhesion layer such as tantalum followed by a DLC layer. The CMP-assisted lift-off of the photoresist and the excess materials is executed at this point. The photoresist used to protect the selected area of the sensor structure is lifted-off using the slurry.

Abstract: A magnetic sensor is provided, having two bias layers separated by a decoupling layer to eliminate exchange coupling between the bias layers. The two bias layers may have differing coercivities, such that the biases provided by the bias layers to the free layer are independently adjustable. The grain structures of the two bias layers may be substantially decorrelated by the decoupling layer.

Abstract: A method for fabricating a sensor having anti-parallel tab regions. The method includes forming a free layer, and forming a first layer of a carbon composition above the active area of the free layer. A layer of resist is formed above the first layer of carbon composition. A bias layer is formed above the tab areas of the free layer, the bias layer being operative to substantially pin magnetic moments of the tab areas of the free layer. Leads are formed above the bias layer. A second layer of carbon composition is formed above the tab areas of the free layer. Any material above a plane extending parallel to portions of the second layer of carbon composition above the tab areas are removed using chemical-mechanical polishing. Any remaining carbon composition is removed.

Abstract: A method for constructing a magnetoresistive sensor using an etch mask that is resistant to the material removal process used to define the sensor width and stripe height. The method may include the use of a Ta etch mask formed under a photoresist mask, and the use of an ion milling process to define the sensor. The etch mask remains substantially intact after performing the ion milling and therefore is readily removed by a later CMP process. The etch mask layer is also very resistant to high temperatures such as those used in a desired atomic layer deposition of alumina, which is used to deposit conformal layers of alumina around the sensor.

Abstract: A read head has a bottom lead made of material that is relatively polish resistant and a top lead layer that polishes down more easily than the bottom layer. With this structure, when the layers are deposited and then polished down, the top layer recesses away from the sensor (and bottom lead layer) in a controlled fashion, providing an acceptable lead structure that reduces the mismatch between the read head physical read width and magnetic read width.

Abstract: A process is described for fabricating sliders with reduced lapping damage to the hard-bias materials. The stack of layers for the magnetic sensor is deposited on a wafer and patterned into an initial shape. The hard-bias structures are fabricated at the side of the magnetic sensor as in the prior art. In each of the two described embodiments of the invention, the hard-bias material below the ABS is reduced or removed and replaced with a fill material such as alumina. A first embodiment reduces the hard-bias material below the ABS by forming an extended lapping gap along the ABS in both the sensor and hard-bias material. A second embodiment forms a photoresist mask over the sensor and the portion of the hard-bias/lead structures above the ABS and the exposed hard-bias/lead material below the ABS is thinned or completely removed by milling.