Western Digital Technologies, Inc.

Michael Gribelyuk

Quang Le

Brian Rodrick York

Cherngye Hwang

Xiaoyong Liu

Kuok San Ho

Hisashi Takano

Xiaoyu Xu

Randy G Simmons

Susumu Okamura

Son T Le

Alan Spool

Nam Hai Pham

Andrew Chen

Huy H Ho

Jinming Liu

Xing-Cai Guo

Khang H D Nguyen

Julian Sasaki

Nitrogen doping an insulating layer can lower the bandgap of a magnetic storage device. It is challenging to nitrogen dope magnesium oxide (MgO). A cation can be added to allow the magnesium to hold onto the nitrogen dopant without highly oxidizing or nitriding the cation. The resulting nitrogen doped MgXO, where X is the cation, has a lower bandgap compared to a much similar barrier layer that has neither nitrogen nor a cation thus improving thermal and electrical reliabilities. The nitrogen doped MgXO is non-stoichiometric whereas comparably, an oxynitride is stoichiometric. Example cations that may be used include aluminum, titanium, vanadium, chromium, and scandium.

Nitrogen doped oxides for lower bandgap

The present disclosure generally relate to spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices comprising a buffer layer, a bismuth antimony (BiSb) layer having a (012) orientation disposed on the buffer layer, and an interlayer disposed on the BiSb layer. The buffer layer and the interlayer may each independently be a single layer of material or a multilayer of material. The buffer layer and the interlayer each comprise at least one of a covalently bonded amorphous material, a tetragonal (001) material, a tetragonal (110) material, a body-centered cubic (bcc) (100) material, a face-centered cubic (fcc) (100) material, a textured bcc (100) material, a textured fcc (100) material, a textured (100) material, or an amorphous metallic material. The buffer layer and the interlayer inhibit antimony (Sb) migration within the BiSb layer and enhance uniformity of the BiSb layer while further promoting the (012) orientation of the BiSb layer.

Buffer layers and interlayers that promote BiSbx (012) alloy orientation for sot and MRAM devices

The present disclosure generally relates to spin-orbit torque (SOT) device comprising a first bismuth antimony (BiSb) layer having a (001) orientation. The SOT device comprises a first BiSb layer having a (001) orientation and a second BiSb layer having a (012) orientation. The first BiSb layer having a (001) orientation is formed by depositing an amorphous material selected from the group consisting of: B, Al, Si, SiN, Mg, Ti, Sc, V, Cr, Mn, Y, Zr, Nb, AlN, C, Ge, and combinations thereof, on a substrate, exposing the amorphous material to form an amorphous oxide surface on the amorphous material, and depositing the first BiSb layer on the amorphous oxide surface. By utilizing a first BiSb layer having a (001) orientation and a second BiSb having a (012) orientation, the signal through the SOT device is balanced and optimized to match through both the first and second BiSb layers.

Highly textured 001 BiSb and materials for making same

The present disclosure generally relates to spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices comprising a doped bismuth antimony (BiSbE) layer having a () orientation. The devices may include magnetic write heads, read heads, or MRAM devices. The dopant in the BiSbE layer enhances the () orientation. The BiSbE layer may be formed on a texturing layer to ensure the () orientation, and a migration barrier may be formed over the BiSbE layer to ensure the antimony does not migrate through the structure and contaminate other layers. A buffer layer and interlayer may also be present. The buffer layer and the interlayer may each independently be a single layer of material or a multilayer of material. The buffer layer and the interlayer inhibit antimony (Sb) migration within the doped BiSbE layer and enhance uniformity of the doped BiSbE layer while further promoting the () orientation of the doped BiSbE layer.

Doping process to refine grain size for smoother BiSb film surface

The present disclosure generally relates to spin-orbit torque (SOT) devices comprising a bismuth antimony (BiSb) layer. The SOT devices further comprise one or more GeNiFe layers, where at least one GeNiFe layer is disposed in contact with the BiSb layer. The GeNiFe layer has a thickness less than or equal to about 15 Å when used as an interlayer on top of the BiSb layer or less than or equal to 40 Å when used as a buffer layer underneath the BiSb. When the BiSb layer is doped with a dopant comprising a gas, a metal, a non-metal, or a ceramic material, the GeNiFe layer promotes the BiSb layer to have a (012) orientation. When the BiSb layer is undoped, the GeNiFe layer promotes the BiSb layer to have a (001) orientation. Utilizing the GeNiFe layer allows the crystal orientation of the BiSb layer to be selected.

Doped BiSb (012) or undoped BiSb (001) topological insulator with GeNiFe buffer layer and/or interlayer for SOT based sensor, memory, and storage devices

The present disclosure generally relate to spin-orbit torque (SOT) devices. The SOT devices each comprise a non-magnetic layer, a free layer disposed in contact with the non-magnetic layer, and a bismuth antimony (BiSb) layer disposed over the free layer. The non-magnetic layer has a thickness of about 0.5 nm to about 2 nm. The BiSb layer has a thickness of about 5 nm to about 10 nm. The BiSb layer and the free layer have collective thickness between about 5 nm to about 20 nm. By reducing the thickness of the non-magnetic layer and BiSb layer, a read gap of each SOT device is reduced while enabling large inverse spin Hall angles and high signal-to-noise ratios.

SOT reader using BiSb topological insulator

Buffer layers and interlayers that promote BiSbx (012) alloy orientation for SOT and MRAM devices

A SOT device includes a bismuth antimony dopant element (BiSbE) alloy layer over a substrate. The BiSbE alloy layer is used as a topological insulator. The BiSbE alloy layer includes bismuth, antimony, AND a dopant element. The dopant element is a non-metallic dopant element, a metallic dopant element, and combinations thereof. Examples of metallic dopant elements include Ni, Co, Fe, CoFe, NiFe, NiCo, NiCu, CoCu, NiAg, CuAg, Cu, Al, Zn, Ag, Ga, In, or combinations thereof. Examples of non-metallic dopant elements include Si, P, Ge, or combinations thereof. The BiSbE alloy layer can include a plurality of BiSb lamellae layers and one or more dopant element lamellae layers. The BiSbE alloy layer has a (012) orientation.

Bismuth antimony alloys for use as topological insulators

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San Jose, CA, United States of America

Michael Gribelyuk