摘要:
A three terminal magnetic sensing device (TTM) having a trackwidth defined in a localized region by a patterned insulator, and methods of making the same, are disclosed. In one illustrative example, one or more first sensor layers (e.g. which includes a “base” layer) are formed over a collector substrate. A patterned insulator which defines a central opening exposing a top layer of the one or more first sensor layers is then formed. The central opening has a width for defining a trackwidth (TW) of the TTM. Next, one or more second sensor layers are formed over the top layer of the one or more first sensor layers through the central opening of the patterned insulator. The one or more second sensor layers may include a tunnel barrier layer formed in contact with the top layer of the one or more first sensor layers, as well as an “emitter” layer. Various embodiments and techniques are provided.
摘要:
A three terminal magnetic sensing device (TTM) having a trackwidth defined in a localized region by a patterned insulator, and methods of making the same, are disclosed. In one illustrative example, one or more first sensor layers (e.g. which includes a “base” layer) are formed over a collector substrate. A patterned insulator which defines a central opening exposing a top layer of the one or more first sensor layers is then formed. The central opening has a width for defining a trackwidth (TW) of the TTM. Next, one or more second sensor layers are formed over the top layer of the one or more first sensor layers through the central opening of the patterned insulator. The one or more second sensor layers may include a tunnel barrier layer formed in contact with the top layer of the one or more first sensor layers, as well as an “emitter” layer. Various embodiments and techniques are provided.
摘要:
Read sensors and associated methods of fabrication are disclosed. A read sensor as disclosed herein includes a first shield, a sensor stack including an antiparallel (AP) free layer, and insulating material disposed on the sensor stack. A aperture is formed through the insulating material above the sensor stack so that a subsequently deposited second shield is electrically coupled to the sensor stack through the aperture. The width of the aperture controls the current density that is injected into the top of the sensor stack. Also, hard bias structures may be formed to be electrically coupled to the sensor stack. The electrical coupling of the sensor stack and the hard bias structures allows current to laterally spread out as it passes through the sensor stack, and hence, provides a non-uniform current density.
摘要:
A current-perpendicular-to the-plane (CPP) magnetoresistive device, such as a magnetic tunnel junction (MTJ), is formed by patterning a capping layer (e.g., using resist) in the shape of a central region of an underlying free ferromagnetic layer that in turn resides over additional layers of the MTJ. Side regions of the capping layer are removed by ion milling or etching down into the free ferromagnetic layer. Unmasked side regions of the ferromagnetic layer are then oxidized to render them locally non-ferromagnetic and electrically insulating.
摘要:
Read sensors and associated methods of fabrication are disclosed. A read sensor as disclosed herein includes a first shield, a sensor stack including an antiparallel (AP) free layer, and insulating material disposed on the sensor stack. A aperture is formed through the insulating material above the sensor stack so that a subsequently deposited second shield is electrically coupled to the sensor stack through the aperture. The width of the aperture controls the current density that is injected into the top of the sensor stack. Also, hard bias structures may be formed to be electrically coupled to the sensor stack. The electrical coupling of the sensor stack and the hard bias structures allows current to laterally spread out as it passes through the sensor stack, and hence, provides a non-uniform current density.
摘要:
In one illustrative example, a three terminal magnetic sensor (TTM) suitable for use in a magnetic head has a sensor stack structure which includes a base region, a collector region, and an emitter region. A first barrier layer separates the emitter region from the base region, and a second barrier layer separates the collector region from the base region. A plurality of terminals of the TTM include a base lead coupled to the base region, a collector lead coupled to the collector region, and an emitter lead coupled to the emitter region. Preferably, the base region consists of a free layer structure so as to have a relatively small thickness. A pinned layer structure is made part of the emitter region. An in-stack longitudinal biasing layer (LBL) structure is formed in stack with the sensor stack structure and has a magnetic moment that is parallel to a sensing plane of the TTM for magnetically biasing the free layer structure. The in-stack LBL structure is made part of the collector region which also includes a layer of semiconductor material. In one variation, the emitter region has the in-stack LBL structure and the collector region has the pinned layer structure. The TTM may comprise a spin valve transistor (SVT), a magnetic tunnel transistor (MTT), or a double junction structure.
摘要:
A magnetic tunnel junction (MTJ) device usable as a magnetic memory cell or magnetoresistive sensor, such as a MTJ read head for magnetic recording, has the free ferromagnetic layer located on the bottom of the device, the bottom free layer being formed on a special underlayer. The MTJ read head may be a flux-guided head that uses the free layer as a flux guide for directing magnetic flux from the magnetic media to the sensing region of the MTJ. The special underlayer for the growth of the free layer is an alloy comprising Mn, one of Pt, Ni, Ir and Os, and an additive X selected from Ta, Al, Ti, Cu, Cr and V. Without the additive, the underlayer alloy is antiferromagnetic. The additive is present in an amount sufficient to render the alloy to have no magnetic ordering, i.e., it is neither antiferromagnetic nor ferromagnetic, but without substantially affecting the preferred crystalline texture and unit cell size so that the underlayer is well-suited as a growth-enhancing underlayer for the free layer.
摘要:
A magnetization of a ferromagnetic free layer of a current-in-plane (CIP) sensor is stabilized using an in-stack longitudinal bias structure that includes a ferromagnetic bias layer and an anti-ferromagnetic bias layer. An electrically insulating layer separates the ferromagnetic free layer and the in-stack longitudinal bias structure, and thus the leads attached to the CIP sensor do not make direct electrical contact with the in-stack longitudinal bias structure. As a result, the sense current shunted by the in-stack longitudinal bias structure is prevented. Since a width along the off track direction of the in-stack longitudinal bias structure is greater than the track-width of the CIP sensor, the edge magnetostatic coupling filed acting on the ferromagnetic free layer from the track width edges of the in-stack longitudinal bias structure is reduced to approximately zero.
摘要:
A method for making a current-perpendicular-to the-plane giant magnetoresistance (CPP-GMR) sensor with a Heusler alloy pinned layer on the sensor's Mn-containing antiferromagnetic pinning layer uses two annealing steps. A layer of a crystalline non-Heusler alloy ferromagnetic material, like Co or CoFe, is deposited on the antiferromagnetic pinning layer and a layer of an amorphous X-containing ferromagnetic alloy, like a CoFeBTa layer, is deposited on the Co or CoFe crystalline layer. After a first in-situ annealing of the amorphous X-containing ferromagnetic alloy, the Heusler alloy pinned layer is deposited on the amorphous X-containing ferromagnetic layer and a second high-temperature annealing step is performed to improve the microstructure of the Heusler alloy pinned layer.
摘要:
A current-perpendicular-to-the-plane (CPP) spin-valve (SV) magnetoresistive sensor uses an antiparallel (AP) pinned structure and has a ferromagnetic alloy comprising Co, Fe and Si in the reference layer of the AP-pinned structure and optionally in the CPP-SV sensor's free layer. The reference layer or AP2 layer is a multilayer of a first AP2-1 sublayer that contains no Si and is in contact with the AP-pinned structure's antiparallel coupling (APC) layer, and a second AP2-2 sublayer that contains Si and is in contact with the CPP-SV sensor's spacer layer. The Si-containing alloy may consist essentially of only Co, Fe and Si according to the formula (CoxFe(100-X))(100-y)Siy where the subscripts represent atomic percent, x is between about 45 and 55, and y is between about 20 and 30.
摘要翻译:电流垂直平面(CPP)自旋阀(SV)磁阻传感器使用反平行(AP)钉扎结构,并且在AP钉扎结构的参考层中具有包含Co,Fe和Si的铁磁合金 并且可选地在CPP-SV传感器的自由层中。 参考层或AP2层是不含Si且与AP钉扎结构的反向平行耦合(APC)层接触的第一AP2-1子层的多层,以及含有Si的第二AP2-2子层 与CPP-SV传感器的间隔层接触。 含Si的合金基本上可以由下式(Co x Fe(100-x))(100-y)Si y的仅Co,Fe和Si组成,其中下标表示原子百分数,x在约45和55之间,y 在大约20到30之间。