H01F41/30

Magnetic Tunnel Junction with Low Defect Rate after High Temperature Anneal for Magnetic Device Applications
20200395534 · 2020-12-17 ·

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.

Minimal thickness synthetic antiferromagnetic (SAF) structure with perpendicular magnetic anisotropy for STT-MRAM

A synthetic antiferromagnetic structure for a spintronic device is disclosed and has an FL2/Co or Co alloy/antiferromagnetic coupling/Co or Co alloy/CoFeB configuration where FL2 is a ferromagnetic free layer with intrinsic PMA. Antiferromagnetic coupling is improved by inserting a Co or Co alloy dusting layer on top and bottom surfaces of the antiferromagnetic coupling layer. The FL2 layer may be a L10 ordered alloy, a rare earth-transition metal alloy, or an (A1/A2).sub.n laminate where A1 is one of Co, CoFe, or an alloy thereof, and A2 is one of Pt, Pd, Rh, Ru, Ir, Mg, Mo, Os, Si, V, Ni, NiCo, and NiFe, or A1 is Fe and A2 is V. A method is also provided for forming the synthetic antiferromagnetic structure.

Multiple hard mask patterning to fabricate 20nm and below MRAM devices

A method for etching a magnetic tunneling junction (MTJ) structure is described. A stack of MTJ layers on a bottom electrode on a wafer is provided. A metal hard mask layer is provided on the MTJ stack. A stack of multiple dielectric hard masks is formed on the metal hard mask wherein each successive dielectric hard mask has etch selectivity with respect to its underlying and overlying layers. The dielectric hard mask layers are etched in turn selectively with respect to their underlying and overlying layers wherein each successive pattern size is smaller than the preceding pattern size. The MTJ stack is etched selectively with respect to the bottommost combination dielectric and metal hard mask pattern to form a MTJ device having a MTJ pattern size smaller than a bottommost pattern size.

Method of producing a magnetic structure

A device and to a method of producing a device, wherein the method includes, inter alia, providing a substrate and generating at least two mutually spaced-apart cavities within the substrate. In accordance with the invention, each cavity has a depth of at least 50 m. The cavities are filled up with magnetic particles, wherein the magnetic particles enter into contact with one another at points of contact, and wherein cavities are formed between the points of contact. At least some of the magnetic particles are connected to one another at their points of contact, specifically by coating the magnetic particles, wherein the cavities are at least partly penetrated by the layer produced in the coating process, so that the connected magnetic particles form a magnetic porous structure.

PSTTM device with multi-layered filter stack

MTJ material stacks, pSTTM devices employing such stacks, and computing platforms employing such pSTTM devices. In some embodiments, perpendicular MTJ material stacks include a multi-layered filter stack disposed between a fixed magnetic layer and an antiferromagnetic layer or synthetic antiferromagnetic (SAF) stack. In some embodiments, non-magnetic layers of the filter stack include at least one of Ta, Mo, Nb, W, or Hf. These transition metals may be in pure form or alloyed with other constituents.

Magnetoresistance element with extended linear response to magnetic fields

A magnetoresistance element assembly has two stacks of material layers with respective reference layers and respective bias layers that have relative magnetic directions that are not perpendicular to each other. Bias layers in the two stacks have bias magnetic directions that oppose each other. Linear range is increased.

Magnetoresistive stack/structure and methods therefor
10811597 · 2020-10-20 · ·

A magnetoresistive device with a magnetically fixed region having at least two ferromagnetic regions coupled together by an antiferromagnetic coupling region. At least one of the two ferromagnetic regions includes multiple alternating metal layers and magnetic layers and one or more interfacial layers. Wherein, each metal layer includes at least one of platinum, palladium, nickel, or gold, and the interfacial layers include at least one of an oxide, iron, or an alloy including cobalt and iron.

Method of manufacturing a magnetoresistive random access memory device

A method of manufacturing an MRAM device, the method including forming a first magnetic layer on a substrate; forming a first tunnel barrier layer on the first magnetic layer such that the first tunnel barrier layer includes a first metal oxide, the first metal oxide being formed by oxidizing a first metal layer at a first temperature; forming a second tunnel barrier layer on the first tunnel barrier layer such that the second tunnel barrier layer includes a second metal oxide, the second metal oxide being formed by oxidizing a second metal layer at a second temperature that is greater than the first temperature; and forming a second magnetic layer on the second tunnel barrier layer.

Magnetoresistive device comprising chromium
10770213 · 2020-09-08 · ·

The disclosed technology generally relates to a magnetoresistive device and more particularly to a magnetoresistive device comprising chromium. According to an aspect, a method of forming a magnetoresistive device comprises forming a magnetic tunnel junction (MTJ) structure over a substrate. The MTJ structure includes, in a bottom-up direction away from the substrate, a free layer, a tunnel barrier layer and a reference layer. The method additionally includes forming a pinning layer over the MTJ structure, wherein the pinning layer pins a magnetization direction of the reference layer. The method additionally includes forming capping layer comprising chromium (Cr) over the pinning layer. The method further includes annealing the capping layer under a condition sufficient to cause diffusion of Cr from the capping layer into at least the pinning layer. According to another aspect, a magnetoresistive device is formed according to the method.

Nitride Capping Layer For Spin Torque Transfer (STT) Magnetoresistive Random Access Memory (MRAM)

A magnetic tunnel junction (MTJ) is disclosed wherein first and second interfaces of a free layer (FL) with a first metal oxide (Hk enhancing layer) and second metal oxide (tunnel barrier), respectively, produce perpendicular magnetic anisotropy (PMA) to increase thermal stability. In some embodiments, a capping layer that is a conductive metal nitride such as MoN contacts an opposite surface of the Hk enhancing layer with respect to the first interface to reduce interdiffusion of oxygen and nitrogen compared with a TiN capping layer and maintain an acceptable resistance x area (RA) product. In other embodiments, the capping layer may comprise an insulating nitride such as AlN that is alloyed with a conductive metal to minimize RA. Furthermore, a metallic buffer layer may be inserted between the capping layer and Hk enhancing layer. As a result, electrical shorts are reduced and the magnetoresistive ratio is increased.