165 results about "Spin injection" patented technology

Source lines for a spin injection magnetic memory cell are arranged parallel to word lines for executing writing / reading of data multiple bits at a time. In a write operation, a source line potential changes in a predetermined sequence such that the source line commonly connected to a plurality of selected memory cells is set to pass a current only in one direction in each stage of the operation sequence. For the data write sequence, a current is caused to flow through memory cells according to write data sequentially, or the memory cell has a resistance state set to an initial resistance state before writing, and then changed to a state according to the write data Fast writing can be achieved in the magnetic memory without increasing a memory cell layout area.

A spin transfer oscillator (STO) structure is disclosed that includes two assist layers with perpendicular magnetic anisotropy (PMA) to enable a field generation layer (FGL) to achieve an oscillation state at lower current density for MAMR applications. In one embodiment, the STO is formed between a main pole and write shield and the FGL has a synthetic anti-ferromagnetic structure. The STO configuration may be represented by seed layer / spin injection layer (SIL) / spacer / PMA layer 1 / FGL / spacer / PMA layer 2 / capping layer. The spacer may be Cu for giant magnetoresistive (GMR) devices or a metal oxide for tunneling magnetoresistive (TMR) devices. Alternatively, the FGL is a single ferromagnetic layer and the second PMA assist layer has a synthetic structure including two PMA layers with magnetic moment in opposite directions in a seed layer / SIL / spacer / PMA assist 1 / FGL / spacer / PMA assist 2 / capping layer configuration. SIL and PMA assist layers are laminates of (CoFe / Ni)x or the like.

A design for a memory array that uses bi-directional write currents and that avoids switched ground connections for memory cells, thereby reducing signal loss and noise problems is described. Positive and negative current sources are provided to supply the bi-directional current that is used to write to a memory cell. These current sources may be selectively connected to bit lines that are electrically connected to the memory cells. Applying a positive current, from the positive current source, through a memory cell writes a “1”, and applying a negative current, from the negative current source, through a memory cell writes a “0”. Use of both a positive and a negative current source enables writing to the memory cells without relying on a switched ground connection to provide bi-directional current. This permits a ground connection of each memory cell to be connected to a fixed ground. An example in which this design is used with a spin injection magneto-resistive random access memory (MRAM) device is shown.

The present invention provides a low-resistance magnetoresistive element of a spin-injection write type. A crystallization promoting layer that promotes crystallization is formed in contact with an interfacial magnetic layer having an amorphous structure, so that crystallization is promoted from the side of a tunnel barrier layer, and the interface between the tunnel barrier layer and the interfacial magnetic layer is adjusted. With this arrangement, it is possible to form a magnetoresistive element that has a low resistance so as to obtain a desired current value, and has a high TMR ratio.

It is possible to reduce a current required for spin injection writing. A magneto-resistance effect element includes: a first magnetization pinned layer; a magnetization free layer; a tunnel barrier layer; a second magnetization pinned layer whose direction of magnetization is pinned to be substantially anti-parallel to the direction of magnetization of the first magnetization pinned layer, and; a non-magnetic layer. When the second magnetization pinned layer is made of ferromagnetic material including Co, material for the non-magnetic layer is metal including at least one element selected from the group consisting of Zr, Hf, Rh, Ag, and Au; when the second magnetization pinned layer is made of ferromagnetic material including Fe, material for the non-magnetic layer is metal including at least one element selected from the group consisting of Rh, Pt, Ir, Al, Ag, and Au; and when the second magnetization pinned layer is made of ferromagnetic material including Ni, material for the non-magnetic layer is metal including at least one element selected from the group consisting of Zr, Hf, Au, and Ag.

A spin-injection magnetic random access memory of an aspect of the present invention includes a magnetoresistive element, a unit which writes data into the magnetoresistive element by use of spin-polarized electrons generated by a spin-injection current and which applies, to the magnetoresistive element, a magnetic field of a direction of a hard magnetization of the magnetoresistive element during the writing.

A spin transfer oscillator with a seed / SIL / spacer / FGL / capping configuration is disclosed with a composite seed layer made of Ta and a metal layer having a fcc(111) or hcp(001) texture to enhance perpendicular magnetic anisotropy (PMA) in an overlying (A1 / A2)X laminated spin injection layer (SIL). Field generation layer (FGL) is made of a high Bs material such FeCo. Alternatively, the STO has a seed / FGL / spacer / SIL / capping configuration. The SIL may include a FeCo layer that is exchanged coupled with the (A1 / A2)X laminate (x is 5 to 50) to improve robustness. The FGL may include an (A1 / A2)Y laminate (y=5 to 30) exchange coupled with the high Bs layer to enable easier oscillations. A1 may be one of Co, CoFe, or CoFeR where R is a metal, and A2 is one of Ni, NiCo, or NiFe. The STO may be formed between a main pole and trailing shield in a write head.

In high frequency magnetic assisted recording technique, a spin torque oscillator that stably oscillates at a low current and a magnetic recording head with high recording density are provided. In a magnetic recording head including an oscillator that generates a high frequency magnetic field, a spin injection layer structure of two laminated magnetic layers which are coupled to be anti-parallel is adopted. A product Ms×t of the saturated magnetization Ms and the film thickness t of the first magnetic layer close to a field generation layer is smaller than a product Ms×t of the second magnetic layer remote from the field generation layer.

A magnetic memory includes a magnetic tunneling junction element having a reference layer, a tunnel barrier layer and a recording layer laminated in order, with information being written to the recording layer in accordance with spin injection magnetization reversal caused by a current, and information written to the recording layer being read out using a current. The magnetic tunneling junction element is disposed on a plug connected to a selection transistor, and a sidewall insulating film covering a side portion of the recording layer of the magnetic tunneling junction element is formed.