# US 10,770,649 B1 · Lattice matched tunnel barriers for perpendicularly magnetized Heusler alloys > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,770,649 B1 - Document ID: US10770649B1 - Status: Granted - Kind: B1 - Application number: 16/281,642 - Filed: 2019-02-21 - Published: 2020-08-27 - Granted: 2020-09-08 - Earliest claimed: 2019-02-21 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Aakash Pushp - Web page: https://patentgrep.com/patent/US10770649B1 ## CPC - H10N 50/80: Constructional details - G11C 11/161: {details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell} - H10N 50/01: Manufacture or treatment - H10N 50/85: Materials of the active region - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR - G11C: STATIC STORES (semiconductor memory devices H10B) ## Abstract A device comprising a first magnetic layer (e.g., Co2MnSi Heusler alloy or a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy such as Mn3Ga, Mn3Ge, etc.) and a second magnetic layer (e.g., Co2MnSi Heusler alloy or a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy such as Mn3Ga, Mn3Ge, etc.), and a metal halide tunnel barrier in between the first and second magnetic layers, wherein the metal halide tunnel barrier (e.g., NaF, NaCl, NaBr, LiF, LiCl, and LiBr or their combination) is lattice matched within a predetermined limit (e.g. 5%) of both the first and second magnetic layers. ## Claims ### Claim 1 A device comprising a first magnetic layer, a second magnetic layer, and a metal halide tunnel harrier between the first and second magnetic layers, wherein the metal halide tunnel barrier is lattice matched to within 5% of both the first and second magnetic layers, and wherein the first layer, the second layer, and the tunnel barrier are in proximity with each other so that spin-polarized current can pass from one of the magnetic layers to the other of the magnetic layers. ### Claim 2 (depends on 1) The device of claim 1, wherein the first magnetic layer is a Co2MnSi Heusler alloy or a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy. ### Claim 3 (depends on 1) The device of claim 1, wherein the second magnetic layer is a Co2MnSi Heusler alloy or a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy. ### Claim 4 (depends on 1) The device of claim 1, wherein each of the first and second magnetic layers is a Co2MnSi Heusler alloy or a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy. ### Claim 5 (depends on 1) The device of claim 1, wherein the metal halide tunnel barrier includes an alkali component and at least one halide component. ### Claim 6 (depends on 5) The device of claim 5, wherein the alkali component is any of, or a combination of, the following: Na and Li. ### Claim 7 (depends on 5) The device of claim 5, wherein the halide component is any of, or a combination of, the following: F, Cl, and Br. ### Claim 8 (depends on 1) The device of claim 1, wherein the halide tunnel barrier is any of, or a combination of, the following: NaF, NaCl, NaBr, LiF, LiCl, and LiBr. ### Claim 9 (depends on 1) A method of forming the device of claim 1 comprising the steps of: depositing the first magnetic layer; epitaxially growing the metal halide tunnel barrier on top of the first magnetic layer, and depositing the second magnetic layer on top of the epitaxially grown halide tunnel barrier. ### Claim 10 (depends on 9) The method of claim 9, wherein the step of depositing the first magnetic layer comprises depositing either a Co2MnSi Heusler alloy layer or a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy layer. ### Claim 11 (depends on 9) The method of claim 9, wherein the step of depositing the second magnetic layer comprises depositing either a Co2MnSi Heusler alloy layer or a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy layer. ### Claim 12 (depends on 9) The method of claim 9, wherein the step of depositing the first magnetic layer comprises depositing either a Co2MnSi Heusler alloy layer or a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy layer, and the step of depositing the second magnetic layer comprises depositing either another Co2MnSi Heusler alloy layer or another tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy layer. ### Claim 13 (depends on 9) The method of claim 9, wherein the metal halide tunnel barrier includes an alkali component and at least one halide component. ### Claim 14 (depends on 13) The method of claim 13, wherein the alkali component is any of, or a combination of, the following: Na and Li. ### Claim 15 (depends on 13) The method of claim 13, wherein the halide component is any of, or a combination of, the following: F, Cl, and Br. ### Claim 16 (depends on 9) The method of claim 9, wherein the step of epitaxially growing the halide tunnel barrier comprises any of, or a combination of, the following: epitaxially growing a NaF tunnel barrier, epitaxially growing a NaCl tunnel barrier, epitaxially growing a NaBr tunnel barrier, epitaxially growing a LiF tunnel harrier, epitaxially growing a LiCl tunnel barrier, and epitaxially growing a LiBr barrier. ### Claim 17 (depends on 9) The method of claim 9, wherein the step of epitaxially growing the halide tunnel barrier is done via RF sputtering. ### Claim 18 (depends on 9) The method of claim 9, wherein the step of epitaxially growing the halide tunnel barrier is done via evaporation. ### Claim 19 A device comprising: a first magnetic layer; a metal halide tunnel barrier underlying the first magnetic layer; and a second magnetic layer underlying the tunnel barrier, wherein: the first magnetic layer, the metal halide tunnel barrier, and the second magnetic layer are in proximity with each other, such that they form a magnetic tunnel junction, the metal halide tunnel barrier is composed of any one of, or a combination of, NaF, NaCl, NaBr, LiF, LiCl, and LiBr, and at least one of the magnetic layers is formed from a Heusler alloy. ### Claim 20 (depends on 19) The device of claim 19, wherein the metal halide tunnel barrier and the Heusler layer are lattice matched to within 5%. ### Claim 21 (depends on 19) The device of claim 19, wherein the first magnetic layer is a Co2MnSi Heusler alloy or a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy. ### Claim 22 (depends on 19) The device of claim 19, wherein the second magnetic layer is a Co2MnSi Heusler alloy or a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy. ### Claim 23 (depends on 19) The device of claim 19, wherein each of the first and second magnetic layers is a Co2MnSi Heusler alloy or a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy. ### Claim 24 (depends on 19) A method of forming the device of claim 19 comprising the steps of: depositing the second magnetic layer made of a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy; epitaxially growing the metal halide tunnel barrier on top of the second magnetic layer, the metal halide tunnel barrier composed of any one of or a combination of NaF, NaCl, NaBr, LiCl, and LiBr, and depositing the first magnetic layer made of a tetragonally distorted perpendicularly magnetized (PMA) Heusler alloy on top of the epitaxially grown metal halide tunnel barrier, wherein the metal halide tunnel barrier is lattice matched to within 5% of both the first and second magnetic layers. ### Claim 25 (depends on 24) The method of claim 24, wherein the step of epitaxially growing the metal halide tunnel barrier is done via RF sputtering. ### Claim 26 (depends on 24) The method of claim 24, wherein the step of epitaxially growing the metal halide tunnel barrier is done via evaporation.