Patent classifications
H01F10/3295
MAGNETIC MEMORY DEVICE AND MANUFACTURING METHOD OF THE SAME
According to one embodiment, a magnetic memory device includes a stacked structure including a first magnetic layer having a fixed magnetization direction, a nonmagnetic layer provided on the first magnetic layer, and a second magnetic layer provided on the nonmagnetic layer and having a variable magnetization direction, a first insulating layer provided along a side surface of the stacked structure and having an upper end located at a position lower than an upper end of the side surface of the stacked structure, and a second insulating layer covering the first insulating layer and having an upper end located at a position higher than the upper end of the first insulating layer.
Magnetic tunnel junction with low defect rate after high temperature anneal for magnetic device applications
A magnetic tunnel junction is disclosed wherein the reference layer and free layer each comprise one layer having a boron content from 25 to 50 atomic %, and an adjoining second layer with a boron content from 1 to 20 atomic %. One of the first and second layers in each of the free layer and reference layer contacts the tunnel barrier. Each boron containing layer has a thickness of 1 to 10 Angstroms and may include one or more B layers and one or more Co, Fe, CoFe, or CoFeB layers. As a result, migration of non-magnetic metals along crystalline boundaries to the tunnel barrier is prevented, and the MTJ has a low defect count of around 10 ppm while maintaining an acceptable TMR ratio following annealing to temperatures of about 400 C. The boron containing layers are selected from CoB, FeB, CoFeB and alloys thereof including CoFeNiB.
MULTILAYERED MAGNETIC FREE LAYER STRUCTURE FOR SPIN-TRANSFER TORQUE (STT) MRAM
A multilayered magnetic free layer structure is provided that includes a first magnetic free layer and a second magnetic free layer separated by a non-magnetic layer in which the second magnetic free layer is composed of a M.sub.1/M.sub.2 superlattice structure or a M.sub.1/M.sub.2 multilayer structure, wherein M.sub.1 is a first magnetic metal selected from the group consisting of cobalt (Co), iron (Fe) and alloys thereof, and M.sub.2 is a second magnetic metal selected from the group consisting of platinum (Pt), palladium (Pd), nickel (Ni), rhodium (Rh), iridium (Jr), rhenium (Re) and alloys thereof.
Magnetic Memory Element Incorporating Perpendicular Enhancement Layer
The present invention is directed to a magnetic memory element including a magnetic free layer structure incorporating three magnetic free layers separated by two perpendicular enhancement layers (PELs) and having a variable magnetization direction substantially perpendicular to layer planes thereof; an insulating tunnel junction layer formed adjacent to the magnetic free layer structure; a first magnetic reference layer formed adjacent to the insulating tunnel junction layer opposite the magnetic free layer structure; a second magnetic reference layer separated from the first magnetic reference layer by a third perpendicular enhancement layer; an anti-ferromagnetic coupling layer formed adjacent to the second magnetic reference layer; and a magnetic fixed layer formed adjacent to the anti-ferromagnetic coupling layer. The first and second magnetic reference layers have a first invariable magnetization direction substantially perpendicular to layer planes thereof. The magnetic fixed layer has a second invariable magnetization direction substantially opposite to the first invariable magnetization direction.
Magnetoresistive element having an adjustable magnetostriction and magnetic device comprising this magnetoresistive element
A magnetoresistive element including: a storage layer having a first storage magnetostriction; a sense layer having a first sense magnetostriction; and a barrier layer between and in contact with the storage and sense layer. The magnetoresistive element also includes a compensating ferromagnetic layer having a second magnetostriction different from the first storage magnetostriction and/or sense magnetostriction, and adapted to compensate the first storage magnetostriction and/or the first sense magnetostriction so that a net magnetostriction of the storage layer and/or sense layer is adjustable between 10 ppm and +10 ppm or more negative than 10 ppm by adjusting a thickness of the compensating ferromagnetic layer. The present disclosure also concerns a magnetic device comprising the magnetoresistive element.
HYBRID OXIDE/METAL CAP LAYER FOR BORON-FREE FREE LAYER
A magnetic tunnel junction stack includes: a pinned layer; a main oxide barrier layer on the pinned layer; a free layer on the main oxide barrier layer; and a hybrid oxide/metal cap layer on the free layer. The hybrid oxide/metal cap layer includes: a first oxide layer on the free layer; a second oxide layer on the first oxide layer; and a metallic cap layer on the second oxide layer, wherein the free layer is free of boron (B).
MAGNETIC SENSOR
A magnetic sensor whose output characteristic is less sensitive to the environmental temperature is provided. Magnetic sensor 1 has free layer 24 whose magnetization direction changes in response to an external magnetic field, pinned layer 22 whose magnetization direction is fixed with respect to the external magnetic field, spacer layer 23 that is located between pinned layer 22 and free layer 24 and that exhibits a magnetoresistance effect, and at least one magnet film 25 that is disposed on a lateral side of free layer 24 and that applies a bias magnetic field to free layer 24. A relationship of 0.7 T.sub.C_HM/T.sub.C_FL1.05 is satisfied, where T.sub.C_HM is Curie temperature of the magnet film, and T.sub.C_FL is Curie temperature of the free layer.
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Magnetic junction device having an inter-layer stack between a hard magnetic layer and a reference layer, and associated magnetic random access memory
The disclosed technology generally relates to magnetic devices, and more particular to a magnetic structure, and a magnetic tunnel junction device and a magnetic random access memory including the magnetic structure. According to an aspect, a magnetic structure for a magnetic tunnel junction (MTJ) device includes a free layer, a tunnel barrier layer, a reference layer, a hard magnetic layer, and an inter-layer stack arranged between the hard magnetic layer and the reference layer. The inter-layer stack includes a first ferromagnetic sub-layer, a second ferromagnetic sub-layer and a non-magnetic spacer sub-layer. The non-magnetic spacer sub-layer is arranged in contact with and between the first ferromagnetic sub-layer and the second ferromagnetic sub-layer and is adapted to provide a ferromagnetic coupling of a magnetization of the first ferromagnetic sub-layer and a magnetization of the second ferromagnetic sub-layer. A magnetization direction of the reference layer is fixed by the hard magnetic layer and the inter-layer stack.
Memory device
The present invention provides a memory device in which lower electrodes, a buffer layer, a seed layer, a magnetic tunnel junction, a capping layer, synthetic exchange diamagnetic layers, and an upper electrode are formed on a substrate in a laminated manner. According to the present invention, the lower electrodes and the seed layer are formed of a polycrystalline conductive material, and the perpendicular magnetic anisotropy of the magnetic tunnel junction is maintained upon heat treatment at a high temperature of 400 C. or more.
Magnetoresistive effect device
A magnetoresistive effect device including a magnetoresistive effect element with which a high-frequency filter can be realized is provided. Magnetoresistive effect device includes: at least one magnetoresistive effect element including a magnetization fixed layer, spacer layer, and magnetization free layer in which magnetization direction is changeable; first and second port; signal line; and direct-current input terminal. First and second ports are connected to each other via signal line. Magnetoresistive effect element is connected to signal line and is to be connected to ground in parallel to second port. Direct-current input terminal is connected to signal line. A closed circuit including magnetoresistive effect element, signal line, ground, and direct-current input terminal is to be formed.