42results about How to "High MR ratio" patented technology

A high performance TMR sensor is fabricated by incorporating a tunnel barrier having a Mg / MgO / Mg configuration. The 4 to 14 Angstroms thick lower Mg layer and 2 to 8 Angstroms thick upper Mg layer are deposited by a DC sputtering method while the MgO layer is formed by a NOX process involving oxygen pressure from 0.1 mTorr to 1 Torr for 15 to 300 seconds. NOX time and pressure may be varied to achieve a MR ratio of at least 34% and a RA value of 2.1 ohm-um2. The NOX process provides a more uniform MgO layer than sputtering methods. The second Mg layer is employed to prevent oxidation of an adjacent ferromagnetic layer. In a bottom spin valve configuration, a Ta / Ru seed layer, IrMn AFM layer, CoFe / Ru / CoFeB pinned layer, Mg / MgO / Mg barrier, CoFe / NiFe free layer, and a cap layer are sequentially formed on a bottom shield in a read head.

There is provided a method for manufacturing a magnetoresistive element having a magnetization pinned layer, a magnetization free layer, and a spacer layer including an insulating layer arranged between the magnetization pinned layer and the magnetization free layer and current paths passing through the insulating layer. The method includes, in producing the spacer layer, depositing a first non-magnetic metal layer forming the current paths, depositing a second metal layer to be converted into the insulating layer on the first non-magnetic metal layer, and performing two stages of oxidation treatments in which a partial pressure of an oxidizing gas in a first oxidation treatment is set to 1 / 10 or less of a partial pressure of an oxidizing gas in a second oxidation treatment, and the second metal layer being irradiated with an ion beam or a RF plasma of a rare gas in the first oxidation treatment.

The present invention provides a manufacturing method of a magneto-resistive element capable of obtaining a higher MR ratio, in a method of forming a metal oxide layer (e.g., MgO layer) by oxidation treatment of a metal layer (e.g., Mg layer). An embodiment of the present invention includes the steps of; providing a substrate having a first ferromagnetic layer; fabricating a tunnel barrier layer on the first ferromagnetic layer; and forming a second ferromagnetic layer on the tunnel barrier layer. The step of fabricating the tunnel barrier layer includes; the steps of; depositing a first metal layer on the first ferromagnetic layer; oxidizing the first metal layer; depositing a second metal layer on the oxidized first metal layer; and performing heating treatment on the oxidized first metal layer and the second metal layer at a temperature at which the second metal layer boils.

A magneto-resistive effect (MR) element includes a first magnetic layer and a second magnetic layer in which a relative angle of magnetization directions of the first and second magnetic layers changes according to an external magnetic field; and a spacer layer that is provided between the first magnetic layer and the second magnetic layer. The spacer layer contains gallium nitride (GaN) as a main component. A thin film magnetic head according to one embodiment of the present invention is provided with the following structures: an MR element mentioned above that has a first magnetic layer and a second magnetic layer, as free layers, in which the magnetization direction in the two layers changes according to the external magnetic field; a bias magnetic field application layer that applies a bias magnetic field to the first and second magnetic layers in an orthogonal direction to an air bearing surface (ABS); the bias magnetic field application layer is formed in a rear side of the MR element seen from the ABS; and a sense current flows in an orthogonal direction to a layer surface of the MR element.

No related magnetoresistive multi-layered films made from a metal magnetic film provide sufficient reproducing output power. A high-polarized layer with a thickness of 10 nm or less is formed as a Fe-rich Fe—O layer in contact with the interface of a non-magnetic intermediate layer and the resulting layers are heat treated to form a multi-layered film of ferromagnetic Fe—O layers, achieving a magnetoresistive element having high magnetoresistance.

A CPP-type magnetoresistive device includes a magnetization pinned layer, a magnetization free layer, and a non-magnetic layer provided between the magnetization pinned layer and the magnetization free layer. At least one of the magnetization free layer and the magnetization pinned layer is formed of CoFeGe, and the CoFeGe has a composition falling within a range defined by line segments connecting coordinate points A, B, C, and D in a ternary composition diagram where the point A is (42.5, 30, 27.5), the point B is (35, 52.5, 12.5), the point C is (57.5, 30.0, 12.5), and the point D is (45.0, 27.5, 27.5), and where each of the coordinate points is represented by content percentage of (Co, Fe, Ge) expressed by atomic percent (at. %).

A magnetic tunneling junction (MTJ) in an MRAM array is disclosed with a composite free layer having a FL1 / FL2 / FL3 configuration where FL1 and FL2 are crystalline magnetic layers and FL3 is an amorphous NiFeX layer for improved bit switching performance. FL1 layer is CoFe which affords a high magnetoresistive (MR) ratio when forming an interface with a MgO tunnel barrier. FL2 is Fe to improve switching performance. NiFeX thickness where X is Hf is preferably between 20 to 40 Angstroms to substantially reduce bit line switching current and number of shorted bits. Annealing at 330° C. to 360° C. provides a high MR ratio of 190%. Furthermore, low Hc and Hk are simultaneously achieved with improved bit switching performance and fewer shorts without compromising other MTJ properties such as MR ratio. As a result of high MR ratio and lower bit-to-bit resistance variation, higher reading margin is realized.