Abstract: A method is presented for controlling process delay times between a) thin film deposition and lubricant application, and b) lubricant application and abrasive polishing. Applicants have discovered that for certain lubricants, a minimum delay time after the overcoat has been deposited before the lubricant is applied increases the number of disks passing the glide test after abrasive polishing. In addition, applicants have discovered that for certain lubricants, the abrasive polishing should take place within a maximum time window following the application of the lubricant. A computerized work-in-progress tracking system is preferably used to implement the method of the invention.

Abstract: Methods for fabricating pole piece tips for a magnetic transducer are disclosed. The ion-milling operations for trimming P2 and notching P1 are controlled using feed-forward and feedback. The preferred method of the invention includes steps for setting four time values used in different phases of the ion-milling process based on feed-forward and feedback of measured values including the P2 width measured in the mask, multiple P2B measurements and measurement of the notch depth.

Abstract: A magnetic head (slider) for perpendicular recording which requires no lapping is described. The head is fabricated with an air bearing surface that is parallel to the wafer surface. The coil and pole pieces are formed from thin films disposed parallel to the air bearing surface. Standard lithographic techniques can be used to define the shapes, gaps and pole piece dimensions. Non-rectilinear shapes can be formed; for example, side shields that conform around the write pole piece region. The thickness of the main and return pole pieces are controlled by the deposition process rather than by lapping. The saw cuts used to separate the individual sliders from the rest of the wafer are perpendicular to the air-bearing surface and do not pass through any critical features.

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 fabricating a coil and pedestal for a write head using a common seed layer is described. A nonmetallic gap layer is deposited on a planarized pole piece surface. Openings for the pole piece pedestal and the back gap pole piece are etched through the nonmetallic gap layer. A seed layer comprising a magnetic material is deposited on the etched gap layer. Preferably the coil is fabricated first on the planar surface of the seed layer. The coil structure, the pedestal pole piece, back-gap pole piece, side and center tap connections are fabricated on the same seed layer. The remaining seed layer is removed, the coil is encapsulated, the wafer is refilled with alumina and the wafer is planarized. The prior art process can be resumed at this point. Optionally a second seed layer such as copper (Cu) can be used.

Abstract: A method of fabricating a magnetic transducer (head) according to the invention includes forming multilayered electrically conductive leads for the magnetic sensor which include a thin tantalum seed layer followed by a thin chromium seed layer which is followed by a thicker rhodium layer. The dual seed layer of the invention significantly improves the conductivity of the rhodium. The Ta/Cr/Rh leads can be used with hard bias structures formed on a PtMn layer without having increased resistance.

Abstract: Heads for perpendicular recording using a floating-trailing shield as part of the magnetic circuit for writing magnetic domains in the recording media are described. The floating-trailing shield is separated from the main pole piece by a layer of non-magnetic material along its entire length and the air bearing surface of the floating-trailing shield is substantially larger than that of the main pole piece. The reluctance between the trailing shield and the underlayer in the recording medium is made so low that both are at the same magnetomotive force (or potential), so that no direct connection is needed between the floating-trailing shield and the yoke. When the head is used in a storage system with a magnetic recording medium with a soft underlayer, the floating-trailing shield is, in effect, magnetically shorted to the return pole piece during recording.

Abstract: A method for fabricating a magnetic head with a trapezoidal shaped pole piece tip is described. The body of the main pole piece is deposited, then one or more layers for the pole piece tip are deposited. A bed material is deposited over the pole piece tip material. A void is formed in the bed material over the area for the pole piece tip. The void is filled with an ion-milling resistant material such as alumina preferably using atomic layer deposition or atomic layer chemical vapor deposition. The excess ion-milling resistant material and the bed material are removed. The result is an ion-milling mask formed over the area for the pole piece tip. Ion milling is then used to remove the unmasked material in the pole piece tip layer and to form a beveled pole piece tip and preferably a beveled face on the main pole piece.

Abstract: A method for forming metrology structures for a CMP process is described. A trench edge is formed in a base material or stack of materials which are preferably deposited as part of the process of fabricating the production structures on the wafer. A covering film of a second material with preferably with contrasting SEM properties is deposited over the trench edge in the base material. During CMP the covering film is preferentially worn away at the edge revealing the base material. The width of the base material which has been revealed is a measure of the progress of the CMP. Since the base material and the covering material are preferably selected to have contrasting images in an SEM, a CD-SEM can be used to precisely measure the CMP progress.

Abstract: A process is described for fabricating magnetic transducers with metallic thin films with a corrosion resistant surface produced by exposing the thin films to a nitrogen in a plasma chamber. The exposure to the nitrogen is believed to increase the corrosion resistance of the metallic thin films by causing nitrides to form in a thin surface region. In the preferred embodiment the thin film metals of a magnetic transducer are treated with the nitrogen after being cut from the wafer and lapped. Typical metals used in magnetic transducers are NiMn, FeMn, NiFe, cobalt, CoFe, copper, IrMn and PtMn. The films may be further protected by the addition of prior art protective layers such as carbon.

Abstract: A process for fabricating sliders where the sliders are held in place during processing by a solid matrix material is described. A thin coating of a release-layer material is applied on the sliders before encapsulation in the matrix material. The release-layer material is polyvinyl alcohol and more preferably high molecular weight polyvinyl alcohol which is highly hydrolyzed. Use of the release-layer of the invention maintains the process resistance while providing the advantage of allowing easier removal of the matrix material after it is no longer needed. The release-layer can be applied to encapsulant materials including epoxies, acrylates, polyimides, silsesquioxanes and others. After the selected fabrication process such as the formation of air-bearing features an appropriate solvent is applied to soften the polyvinyl alcohol film and allow clean debonding of the sliders.

Abstract: A disk drive with switchable power levels for the heaters in the sliders is disclosed. The invention includes a switch for the electrical circuit of each heater which selects between two or more voltages to apply to the power control element and the heater with at least a high and a low voltage option. The heater power control circuit dissipates a certain amount of heat as a part of the control process. By having a low voltage option the disk drive can save power and reduce the amount of heat dissipated by the heater control circuit when high power is not required. The programmable switch is controlled by the drive control system. The high power setting can be used during manufacturing testing or otherwise if higher heater power is needed. The low power setting is used for normal operation or to save power.

Abstract: A method for measuring the clearance of a slider over a rotating disk by inducing a collision between the slider and the disk is described. After the normal flying height of the slider is established, the slider is driven into a collision with the rotating disk surface by applying a DC or AC voltage between the slider and the disk. The clearance data can be extracted from the induced collision by measuring a parameter, such as the change in the amplitude of the readback signal from the magnetic sensor, which is related to fly-height at the normal fly-height and at the disk surface. The two data points can then be used to derive the clearance. One embodiment uses a single beam interferometer to derive the vibrational displacement of the collision event.

Abstract: An exchange-coupled magnetic structure includes a ferromagnetic layer, a coercive ferrite layer, such as cobalt-ferrite, for biasing the magnetization of the ferromagnetic layer, and an oxide underlayer, such as cobalt-oxide, in proximity to the coercive ferrite layer. The oxide underlayer has a lattice structure of either rock salt or a spinel and exhibits no magnetic moment at room temperature. The underlayer affects the structure of the coercive ferrite layer and therefore its magnetic properties, providing increased coercivity and enhanced thermal stability. As a result, the coercive ferrite layer is thermally stable at much smaller thicknesses than without the underlayer. The exchange-coupled structure is used in spin valve and magnetic tunnel junction magnetoresistive sensors in read heads of magnetic disk drive systems. Because the coercive ferrite layer can be made as thin as 1 nm while remaining thermally stable, the sensor satisfies the narrow gap requirements of high recording density systems.

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 method of longitudinal recording using a medium with a magnetically soft underlayer is described. The method includes lowering the longitudinal coercivity in a magnetic domain in the magnetic recording medium by generating a vertical component of magnetic flux in the magnetic recording medium and writing a longitudinal orientation in the magnetic domain in the magnetic recording medium by generating a larger horizontal component of magnetic flux in the magnetic recording medium using the write head. Optionally the method further includes magnetically saturating the magnetically soft underlayer after lowering the longitudinal coercivity to limit the vertical component of the magnetic flux. The recording medium has a magnetic recording layer, a spacer layer and a soft underlayer. In one embodiment the soft underlayer is an antiferromagnetically coupled magnetic layer stack with two soft magnetic layers separated by a non-magnetic spacer layer selected to achieve the antiferromagnetic coupling.

Abstract: A method for producing a magnetic transducer with an inductive write head having a multilayer coil with a high aspect ratio and a short yoke is disclosed. A damascene process is used for two coil layers and a conventional process for the third coil layer. The process of the invention allows a seed layer for the coil to be deposited on the side walls of the trenches for the first and second coil layers. In one embodiment the seed layer for the coil is preceded by an adhesion layer.

Abstract: A magnetic recording transducer, useful in a magnetic data storage device, having a read element with improved magnetic stability and a narrow track width is described. An MR stripe according to the invention has a magnetic-stability inducing (MSI) shape selected from an essentially trapezoidal shape, an essentially hexagonal shape, an essentially race-track shape, and an essentially half race track shape. These MSI shapes are oriented in a plane perpendicular to the air-bearing surface (ABS). The MSI shapes are used to encourage the formation of a single magnetic domain state with magnetization direction parallel to the ABS in the absence of a magnetic bias. In one embodiment according to the invention the sensor structure is overlaid on the sides of the top surface with layers of electrically conductive material (overlaid leads) to define an approximately rectangular active region of the larger MSI shape.

Abstract: A method is presented for glide testing a disk which tests the glide head fly-height by inducing a collision between the glide head and a disk under test. The glide test system is initially calibrated using calibration disks. The method of the invention periodically tests the calibration without interrupting the production testing by lowering the rotation rate until the glide head collides with the rotating disk surface. The rotation rate at which the collision occurs is then compared with the value expected based on knowledge of disk samples and the initial calibration. Parameters for acceptable high and low values are established to detect changes in the glide test system performance to trigger automatic or manual recalibration.

Abstract: The method of the invention for servo track writer calibration consists of writing magnetic servo tracks and performing optical analysis using Kerr effect microscopy. After the servo tracks are written on the disk, the disk is placed in the optical inspection device having Kerr effect microscopy capability which allows the operator to directly observe the location of “track zero” which is conventionally the track nearest to the inner diameter (ID) of the disk. An embodiment of the method comprising measuring a plurality of distances from a selected points on the track zero to obtain an average measurement indicative of a position of track zero on the magnetic disk. The measured data is then used to calibrate or adjust the servo writer.