Abstract: Dual and triple PMR writers are disclosed wherein the number of writer pads required to energize the selected PMR writer is minimized to three or four, respectively, with a coil configuration wherein separate top coils are connected by separate interconnects or side taps to separate bottom coils. Either top coils or bottom coils may be linked to a common W? pad. Alternatively, there may be one bottom coil that allows all output current to flow to a common W? pad. Coils may have a pancake or helical shape. In dual PMR writer embodiments, there may be one or two dynamic fly height heater coils. Magnetic performance in the selected writer of a dual PMR writer is similar to that of a single PMR writer with regard to erase width in AC mode (EWAC), Hy field, trailing and side shield return fields, down-track and cross-track gradient.

Abstract: A Spin Hall Effect (SHE) assisted magnetic recording device is disclosed wherein a SHE layer comprising a giant Spin Hall Angle material is formed between a main pole (MP) trailing side and trailing shield (TS) bottom surface. The SHE layer may contact one or both of the MP and TS, and has a front side at the air bearing surface (ABS) or recessed therefrom. A first current (I1) is applied between the MP trailing side and SHE layer and is spin polarized to generate a first spin transfer torque that tilts a local MP magnetization to a direction that enhances a MP write field. A second current (I2) is applied between the SHE layer and TS and is spin polarized to generate a second spin transfer torque that tilts a local TS magnetization to a direction that increases the TS return field and improves bit error rate.

Abstract: A PMR writer is disclosed wherein the trailing shield (TS) structure has a high moment trailing shield (HMTS) with a saturation (Bs) from 19 kiloGauss (kG) to 24 kG and a width (w) from 10 nm to 500 nm and is separated from the main pole (MP) trailing side at an air bearing surface (ABS) by a first write gap (WG) portion of thickness t1. A second WG portion of thickness t2 where t2>t1 adjoins the sides of the first WG portion, and has an outer side at a cross-track distance ½ w1 from a center plane that bisects the MP trailing side where w1>w. A first TS layer is formed on the HMTS and on the second WG portion, and has an outer side coplanar with the second WG portion outer side. Accordingly, there is improvement in tracks per inch capability and adjacent track interference.

Abstract: A disk drive head assembly includes a spin torque oscillator (STO) situated between a main pole and a trailing shield. A head-disk interference (HDI) sensor is placed between the main pole and a read sensor shield. A trace is connected between a preamplifier and the head assembly for providing a first biasing voltage level to the spin torque oscillator (STO) and to the head-disk interference (HDI) sensor for determining resistance changes in the head-disk interference (HDI) sensor. Further, the preamplifier is configured for determining a resistance change in the head-disk interference (HDI) sensor based on a change in current through the head-disk interference (HDI) sensor. The spin torque oscillator (STO) and the head-disk interference (HDI) sensor are connected in parallel to two connectors from the two contacting pads on the preamplifier.

Abstract: A MTJ stack comprising at least a pinned layer, a barrier layer, and a free layer is deposited on a bottom electrode. A top electrode layer, a carbon-based hard mask, and a dielectric hard mask are deposited in order on the MTJ stack. First, the hard masks and MTJ stack are etched. The etched MTJ stack has a first width. During the first etching, chemical damage forms on sidewalls of the MTJ stack. Next, the carbon-based hard mask is trimmed to a second width smaller than the first width. Then in a second etching, the top electrode and free layer of said MTJ stack not covered by the trimmed carbon-based hard mask are etched to complete formation of the MTJ structure wherein during the second etching of the free layer, chemical damage is removed from the free layer and metal re-deposition is formed on sidewalls of the free layer.

Abstract: A Spin Hall Effect (SHE) assisted magnetic recording device is disclosed wherein a stack of two SHE layers (SHE1 and SHE2) with an intermediate conductor layer is formed between a main pole (MP) trailing side and trailing shield (TS) bottom surface. SHE1 is a negative Spin Hall Angle (SHA) material while SHE2 is a positive SHA material. Current (Ia) flows from SHE1 across the conductor layer to SHE2. In one embodiment, spin polarized current in SHE1 applies spin transfer torque that tilts a local MP magnetization to a direction that enhances a MP write field, and spin polarized current in SHE2 generates spin transfer torque that tilts a local TS magnetization to a direction that increases the TS return field and improves bit error rate. In alternative embodiments, one of SHE1 and SHE2 is omitted so that only one of the MP write field and TS return field is enhanced.

Abstract: Reader-to-reader separation (RRS) is substantially decreased, and cross-track alignment of top and bottom sensors is improved with a process where a sidewall on the two sensors is formed during a single photolithography and ion beam etch sequence. RRS is minimized since the two sensors share a common reference layer (RL), and shields between the readers are omitted. A RL front portion is formed on a first stack of layers with a first free layer and uppermost first tunnel barrier, and a RL back portion is on a second stack comprising a reference layer and antiferromagnetic coupling layer sequentially formed on an antiferromagnetic layer. The RL may be a single layer or a synthetic antiferromagnetic structure so that the sensors operate in a common mode or differential mode, respectively. A third stack with a bottom second tunnel barrier and overlying second free layer is formed on the RL front portion.

Abstract: A Spin Hall Effect (SHE) assisted magnetic recording device is disclosed wherein a stack of two SHE layers with an intermediate insulation layer is formed between a main pole (MP) trailing side and trailing shield (TS) bottom surface. Both SHE layers are a Spin Hall Angle (SHA) material with an absolute value for SHA>0.05 and each have front sides at the air bearing surface (ABS) or recessed therefrom. One current (I1) is applied between the MP trailing side and the first SHE layer and is spin polarized to generate spin transfer torque that tilts a local MP magnetization to a direction that enhances a MP write field. Second current (I2) is applied between the second SHE layer and TS and is spin polarized to generate spin transfer torque that tilts a local TS magnetization to a direction that increases the TS return field and improves bit error rate.

Abstract: An MTJ or MR read sensor is formed by depositing a stack in a reverse order with a free layer (FL) deposited on a lower shield, followed by a tunneling barrier layer (for an MTJ) or a conducting spacer layer (for an MR) and, finally, an antiferromagnetically coupled pinning structure and an upper shield. This reverse order permits a series of etching processes to be accurately performed on the lower shield and the stack together with the formation of biasing layers that are coupled to the lower shield and the stack, without adversely affecting the stability of the pinning structure. Further, the distance between the FL and the shield is accurately determined and repeatable even down to the sub-nm regime. An upper shield can then be formed and also coupled to the biasing layers.

Abstract: A perpendicular magnetic recording writer has a main pole (MP) with a first flux guiding (FG) device in a write gap between the MP trailing side and a trailing shield, a second FG device in each side gap and adjoining a MP side, and third FG device in the leading gap and adjoining the MP leading side. At least one of a first and second non-magnetic conductive layer (NMC1 and NMC2) contacts the third FG device and second FG devices, respectively, instead of a conventional leading shield and side shield. Each FG device has a flux guiding layer (FGL) with a magnetization that flips to oppose a gap flux field when a current is applied across the respective gap thereby enhancing the MP write field. NMC1 and NMC2 allow better wear and corrosion resistance in addition to improved return field and down-track field gradient, and acceptable side shield stray field.

Abstract: A microwave assisted magnetic recording writer has a main pole (MP) with a write gap formed between the MP trailing side and a trailing shield, a side gap between each MP side and a side shield, and a leading gap between the MP leading side and a leading shield. A spin torque oscillator (STO) is formed in at least each side gap and recessed from the air bearing surface to reduce wear. Each STO has a flux guiding layer (FGL) with a magnetization that flips to a direction substantially opposite to the gap field when a current of sufficient density is applied from the adjacent shield towards the MP thereby forcing additional flux out of the MP at the ABS to enhance writability on a magnetic recording medium. Accordingly, the gap between the recessed STO and ABS is reduced to provide enhanced area density capability without sacrificing overwrite.

Abstract: A perpendicular magnetic recording writer has a main pole (MP) with a first flux guiding (FG) device in a write gap between the MP trailing side and a trailing shield, and a second FG device in the leading gap (LG) and each side gap (SG). The SG angle is reduced to 15° to 45° to enable conformal and more uniform FG device layers to be formed in the SG and LG. As a result, the MP shape and write field are more reproducible. To compensate for a thinner MP thickness at the air bearing surface that results from maintaining the track width at a shallower SG angle, an upper MP tip may be formed on the lower MP tip thereby generating a hexagonal shape for the combined MP tip. In this case, the second FG device conforms to the shape of the two upper MP tip sides and trailing side.

Abstract: A junction shield (JS) structure is disclosed for providing longitudinal bias to a free layer (FL) having a width (FLW) and magnetization in a cross-track direction between sidewalls in a sensor. The sensor is formed between bottom and top shields and has sidewalls extending from a front side at an air bearing surface (ABS) to a backside that is a stripe height (SH) from the ABS. The JS structure has a lower layer (JS1) with a magnetization parallel to that of the FL, and a tapered top surface such that JS1 has decreasing thickness with increasing height from the ABS. As aspect ratio or AR (SH/FLW) increases above 1, longitudinal bias increases proportionally to slow an increase in asymmetry as AR increases, and without introducing a loss in amplitude for a reader with low AR. The JS1 layer may be antiferromagnetically coupled to an upper JS layer for stabilization.

Abstract: A perpendicular magnetic recording writer is disclosed with a permanent magnet (PM) formed within a write gap (WG) that is between a main pole (MP) trailing side and a trailing shield. The PM has a magnetization that is anti-parallel to a WG field (HWG) when a transition is written thereby enhancing the MP field on a magnetic bit, and generates a PM field that assists the MP field. When HWG becomes saturated after the transition is written and exceeds PM coercivity that is from 500 Oe to 8000 Oe, PM magnetization flips to an opposite direction and reduces the MP field thereby improving adjacent track erasure. The PM may be at the air bearing surface (ABS) or recessed up to 50 nm from the ABS, and has a down-track thickness less than the WG thickness, and a cross-track width?to the track width of the MP trailing side.

Abstract: A method of operating a HDD having a read/write head configured for Perpendicular Magnetic Recording (PMR) and configured for use in Thermally Assisted Magnetic Recording (TAMR). By using selected settings of a power ratio (PR) value to ensure that accurate fly height (FH) measurements of head-disk interference (HDI) can be taken during write touchdowns (TDs), head damage can be eliminated during HDI events. Under normal operating conditions the PMR head develops a sharp protrusion due to heating from the TAMR apparatus as well as the write current and read and write heaters. The sharp protrusion is prone to striking the disk surface, instead of the shields doing so. The shields would be more capable of absorbing the HDI, which would allow the HDI sensors (HDIs) to provide a more sensitive reading of the HDI which would prevent head wear caused by the sharp protrusion.

Abstract: A method is disclosed for forming a perpendicular magnetic recording writer with an all wrap around (AWA) shield design wherein a surface of the leading shield that contacts the lead gap has a notch that is recessed 20 to 120 nm from the air bearing surface (ABS) and has a first side with a down-track dimension of 20-200 nm that is aligned parallel to the ABS. In one embodiment, the notch is aligned below the main pole leading side and has a cross-track width substantially the same as the track width of the main pole trailing side. The notch has two sidewalls formed equidistant from a center plane that bisects the leading shield wherein each sidewall intersects the first side at an angle of 90 to 170 degrees. Accordingly, overwrite and bit error rate are improved while adjacent track interference and tracks per square inch capability are substantially maintained.

Abstract: A PMR writer is disclosed wherein a top yoke (TY) is extended toward the air bearing surface (ABS) and below a top coil for faster saturation speed and better frequency extendibility without wide adjacent track erasure trade-off. The TY extension has a front side recessed 0.9-1.3 microns from the ABS, and has a backside below an inner corner of a PP3 trailing shield that is 2-2.6 microns from the ABS. TY thickness is from 0.3-0.8 micron and the TY is preferably used with a 1+1T coil design, and a PP3 trailing shield apex angle of 60° to 80° for better high data rate performance. Magnetic modeling shows rise time is shorter than for a conventional TY. The top yoke design is compatible with various base writer structures. When used in selectable double writers or selectable triple writers, each writer has a separate TY, main pole, and bottom yoke.

Abstract: A PMR read/write head configured for thermally assisted recording (TAMR) includes thermally active bumper pads formed to each side of a write element to provide enhanced touchdown (TD) protection to the write head element where it emerges adjacent to the plasmon near-field spot produced by the TAMR apparatus. The bumper pads are disposed about the write head and absorb heat energy generated by active heating elements, the write current and the energy generated by the TAMR apparatus. Absorption of this energy causes the bumper pads to expand and protrude outward from the slider ABS to protect the read/write head from both intentional and unanticipated touchdown events. The PMR read/write head is then mounted on a slider and the assembly is incorporated into a hard disk drive (HDD).

Abstract: A bottom shield in a read head is modified by including a non-magnetic decoupling layer and second magnetic layer on a conventional first magnetic layer. The second magnetic layer has a magnetization that is not exchange coupled to the first magnetic layer, and a domain structure that is not directly affected by stray fields due to domain wall motion in the first magnetic layer. Accordingly, the modified bottom shield reduces shield related noise on the reader and will provide improved signal to noise (SNR) ratio and better reader stability. The second magnetic layer may be further stabilized with one or both of an antiferromagnetic coupling scheme, and insertion of an antiferromagnetic pinning layer. In dual readers, the modified bottom shield is used in either the bottom or top reader although in the latter, first magnetic layer thickness is reduced to maintain reader-to-reader spacing and acceptable bit error rate (BER).

Abstract: A hard magnet stabilization scheme is disclosed for a top shield and junction shields for double or triple dimension magnetic reader structures. In one design, the hard magnet (HM) adjoins a top or bottom surface of all or part of a shield domain such that the HM is recessed from the air bearing surface to satisfy reader-to-reader spacing requirements and stabilizes a closed loop magnetization in the top shield. The HM may have a height and width greater than that of the top shield. The top shield may have a ring shape with a HM formed above, below, or within the ring shape, and wherein the HM stabilizes a vortex magnetization. HM magnetization is set or reset from room temperature to 100° C. to maintain a desired magnetization direction in the top shield, junction shield, and free layer in the sensor.