DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Acknowledgement of RCE Filing and Status of Claims
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.
Applicant's submission filed on 08/17/2026 has been entered.
The amendment filed on 08/17/26 has been entered.
Applicant amended Claims 1 and 15.
Claims 1-20 are examined on merits herein.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-4, 7, 9-13, 15-16, and 19-20 are rejected under 35 U.S.C. 103 as being unpatentable over Guo et al. (US 2021/0328134) in view of Wang et al. (NPL) and Krizakova et al. (NPL).
In re Claim 1, Guo teaches a magnetic tunnel junction (MTJ) device, comprising (Fig. 1; see also Figs. 4-6):
an MTJ element 14/13/12 including a magnetic reference layer 14 (paragraph 0030), a magnetic free layer 12 (called “magnetic memory layer” paragraph 0020, but could be identified as “magnetic free” – as in the current application, due to its ability to change magnetization, paragraphs 0030-0031), and a non-magnetic barrier layer 13 (paragraph 0024) separating the magnetic reference layer 14 and the magnetic free layer 12; and
a spin-orbit torque (SOT) layer structure 11/10 (paragraph 0020-0022) arranged below the MTJ element 14/13/12 and configured to provide a write current for switching a magnetization direction of the magnetic free layer through SOT (paragraph 0009, Fig. 5A and paragraph 0030 as directed to influence of magnetic layer 10 on magnetic-free layer 12, and Figs. 6A-6C paragraph 0031 directed to writing); wherein
the SOT layer structure comprises a heavy metal layer 11 (called SHC layer, paragraph 0020, but could be called “heavy metal layer”, as in the current application, comparing its materials in paragraph 0022 with Periodic Table – attached to this Office Action) and a magnetic layer 10 (paragraph 0021); and wherein
the magnetic layer 10 is arranged below the heavy metal layer 11 and configured to, in the absence of an external magnetic field (paragraphs 0027-0028), induce a magnetic field in the magnetic free layer 12 (paragraphs 0009 and 0030), thereby promoting deterministic switching of the magnetization of the magnetic free layer 12 (paragraph 0031), where
in-plane write current is injected into the SOT (paragraph 0007; note that the current application identifies a current injected into a SOT as a write current – see Fig. 3 and paragraph 0049 of the published application US 2024/0155949).
Note that although Guo does not use words: “deterministic switching”, but refers only to “magnetic switching”, the procedure described by Guo is described in some art as “deterministic switching” – see Fig. 1A and paragraph 0049 of Sun, US 2019/0312198, on a common knowledge in the art, to support the statement.
Guo does not teach that each of the magnetic reference layer 14 and the magnetic free layer 12 has a perpendicular magnetic anisotropy (PMA), does not teach that the magnetic layer has an in-plane magnetic anisotropy that is orthogonal to the PMA of the magnetic reference and magnetic free layers, and does not teach (at least, explicitly) that the magnetic layer induces a magnetic field in the magnetic free layer in a direction of the write current passing parallel through both the heavy metal layer and the magnetic layer.
Wang teaches (Abstract) that an MTJ with an in-plane magnetic anisotropy (in magnetic free and magnetic reference layers) has some deficiencies that are absent in an MTJ with a perpendicular magnetic anisotropy (PMA) in both these layers and presents a structure of a SOT- PMA MTJ (Fig. 7, page 1036) in which a write current (called “injected current”) is injected into the SOT parallel to its plane that is orthogonal to the direction of PMA of the MTJ, where the injected current passes, obviously, through both layers of the SOT since these electrically conductive layers are disposed in parallel and are in direct contact; where the write current with a plane orthogonal to the PMA - creates a magnetic field capable to influence the PMA. Wang, however, points out that for successful operation of the SOT-PMA MTJ structure without an external magnetic field - an additional in-plane magnetic field shall be added. Krizakova creates this needed magnetic field (Abstract and page 1) by an in-plane anisotropic (e.g., having a dipole polarization) magnetization of the magnetic layer of the SOT structure, allowing creation of an external magnetic field free SOT PMA MTJ device.
Guo, Wang, and Krizakova teach analogous arts directed to MTJ elements, and one of ordinary skill in the art before the effective date of filing the application would have had a reasonable expectation of success in modifying the Guo device in view of the Wang and Krizakova teachings, since they are from the same field of endeavor, and Wang and Krizakova created successfully operated devices.
It would have been obvious for one of ordinary skill in the art before the effective date of filing the application to modify the Guo device by creating the magnetic reference layer and the magnetic free layer as layers possessing a perpendicular magnetic anisotropy (per Wang), when it is desirable improving a thermal stability of the device and reducing its power consumption (Wang, Abstract).
It would have been further obvious for one of ordinary skill in the art to also modify the SOT structure (unless it is initially formed in a manner described further) by creating its magnetic layer with an in-plane magnetic anisotropy (per Krizakova), which, being “in-plane” (see Fig. 1 of Wang on differences between the in-plane and perpendicular magnetic anisotropy, if required) is orthogonal to the perpendicular magnetic anisotropy of the magnetic reference and magnetic free layers, creating by that the SOT-PMA MTJ device capable of deterministic switching of the magnetization of the magnetic free layer in the absence of an external magnetic field (Wang and Krizakova).
In re Claim 2, Guo/Wang/Krizakova teaches the MTJ device according to Claim 1, wherein the magnetic layer 10 (Guo, Fig. 1, paragraph 0021) includes a material selected from the group consisting of Fe, Co, Ni, FeCo, FeCoB, NiFe, NdFeB, WCoFeB, and TaCoFeB – Guo explicitly teaches Fe, Co, Ni, and NiFe.
In re Claim 3, Guo/Wang/Krizakova teaches the MTJ device according to Claim 1, wherein the magnetic layer 10 (Guo, Fig. 1) has an average thickness in the range of 2-5 nm – Guo teaches a thickness in a range from 1.5 nm to 10 nm (paragraph 0021), and in accordance with MPEP 2144.05 Obviousness of Similar and Overlapping Ranges, Amounts, and Proportions. I. OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS, in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
In re Claim 4, Guo/Wang/Krizakova teaches the MTJ device according to Claim 1, wherein (Guo, Figs. 6A-6B, paragraphs 0011, 0031) the magnetic layer 10 is formed on a bottom electrode BE1, BE2 of the MTJ device.
In re Claim 7, Guo/Wang/Krizakova teaches the MTJ device according to Claim 1 as cited above, wherein the heavy metal layer 11 (Guo, Fig. 1) includes a material selected from the group consisting of W, Ta, Pt, Cu, PtMn, PtCu, and PtCr – from the claimed materials, Guo explicitly teaches Pt and Cu (paragraph 0022).
In re Claim 9, Guo/Wang/Krizakova teaches the MTJ device according to Claim 1 as cited above and wherein the heavy metal layer 11 (Guo, Fig. 1) has an average thickness in the range of 2-6 nm – Guo teaches a thickness in a range from 1.5 nm to 10 nm (paragraph 0022), which encompasses the claimed thickness, and in accordance with MPEP 2144.05 Obviousness of Similar and Overlapping Ranges, Amounts, and Proportions. I. OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS, in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
In re Claim 10, Guo/Wang/Krizakova teaches the MTJ device according to Claim 1 as cited above, wherein (Guo, Figs. 1, 4, 6) the heavy metal layer 11 has a shape corresponding to a shape of the magnetic layer 10 (paragraph 0021).
In re Claim 11, Guo/Wang/Krizakova teaches the MTJ device according to Claim 1, wherein the MTJ element is a top-pinned element, e.g., its magnetic reference layer 14 (Fig. 1) is over the magnetic-free layer 12.
In re Claim 12, Guo/Wang/Krizakova teaches the MTJ device according to Claim 1 as cited above, wherein (Guo, Figs. 1 and 6) the magnetic free layer 12 is formed on the SOT layer structure 11/10.
In re Claim 13, Guo/Wang/Krizakova teaches the MTJ device according to Claim 1 as cited above, wherein the magnetic free layer 12 (Guo, Figs. 1, 6) is formed of a single CoFeB layer or a synthetic-antiferromagnetic hybrid-free layer – Gou teaches a single layer of CoFeB (paragraph 0023).
In re Claim 15, Guo teaches a method of fabricating a magnetic tunnel junction (MTJ) device (obviously, since Guo creates the device) comprising (Figs. 1 and 6):
providing (obviously) an MTJ element 14/13/12 including a magnetic reference layer 14 (paragraph 0030), a magnetic free layer 12 (called “magnetic memory layer”, paragraph 0020, but could be identified as “magnetic free” – as in the current application, since its magnetization is not constant but can be changed, paragraphs 0030-0031), and a non-magnetic barrier layer 13 (paragraph 0024) separating the magnetic reference layer 14 and the magnetic free layer 12; and
providing (obviously) a spin-orbit torque (SOT) layer structure 11/12 (paragraphs 0020-0022) arranged below the MTJ element 14/13/12 and configured to provide a write current for switching a magnetization direction of the magnetic free layer through SOT (paragraph 0009, Fig. 5 and paragraph 0030 on influence of magnetic layer 10 on magnetic-free-layer 12 and Figs. 6A-6C, paragraph 0031, directed to writing and a writing current); wherein
the SOT layer structure 11/10 comprises a heavy metal layer 11 (called SHL layer in paragraph 0020, but it could be called “a heavy metal layer”, as in the current application, comparing its materials in paragraph 0022 with Periodic Table) and a magnetic layer 10 (paragraph 0021); and wherein
the magnetic layer 10 is arranged below the heavy metal layer 11 and configured to, in the absence of an external magnetic field (paragraphs 0027-0028), induce a magnetic field in the magnetic free layer in a direction of the write current through the SOT layer structure (paragraphs 0009, 0030), thereby promoting magnetic switching of the magnetization of the magnetic free layer 12.
Although Guo does not use a combination of words: “deterministic switching”, but refers only to “magnetic switching”, the procedure described by Guo is described in some art as “deterministic switching” – see Fig. 1A and paragraph 0049 of Sun, US 2019/0312198, on a common knowledge in the art, to support the statement.
Guo does not teach that each of the magnetic reference layer 14 and the magnetic free layer 12 has a perpendicular magnetic anisotropy (PMA), does not teach that the magnetic layer has an in-plane magnetic anisotropy that is orthogonal to the PMA of the magnetic reference and magnetic free layers, and does not teach that the magnetic layer induces a magnetic field in the magnetic free layer in a direction of the write current passing parallel through both the heavy metal layer and the magnetic layer.
Wang teaches (Abstract) that an MTJ with an in-plane magnetic anisotropy (in magnetic free and magnetic reference layers) has some deficiencies that are absent in an MTJ with a perpendicular magnetic anisotropy (PMA) in both these layers and presents a structure of a SOT- PMA MTJ (Fig. 7, page 1036) in which a write current (called “injected current”) is injected into the SOT parallel to its plane that is orthogonal to the direction of PMA of the MTJ, where the injected current passes, obviously, through both layers of the SOT since these electrically conductive layers are disposed in parallel and are in direct contact; where the write current with a plane orthogonal to the PMA - creates a magnetic field capable to influence the PMA. Wang, however, points out that for successful operation of the SOT-PMA MTJ structure without an external magnetic field - an additional in-plane magnetic field shall be added. Krizakova creates this needed magnetic field (Abstract and page 1) by an in-plane anisotropic (e.g., having a dipole polarization) magnetization of the magnetic layer of the SOT structure, allowing creation of an external magnetic field free SOT PMA MTJ device.
It would have been obvious for one of ordinary skill in the art before the effective date of filing the application to modify the Guo device by creating the magnetic reference layer and the magnetic free layer as layers possessing a perpendicular magnetic anisotropy (per Wang), when it is desirable improving a thermal stability of the device and reducing its power consumption (Wang, Abstract).
It would have been further obvious for one of ordinary skill in the art to also modify the SOT structure (unless it is initially formed as described further) by creating its magnetic layer with an in-plane magnetic anisotropy (per Krizakova), which, being “in-plane” (see Fig. 1 of Wang on differences between the in-plane and perpendicular magnetic anisotropy, if required) is orthogonal to the perpendicular magnetic anisotropy of the magnetic reference and magnetic free layers, creating by that the SOT-PMA MTJ device capable of deterministic switching of the magnetization of the magnetic free layer in the absence of an external magnetic field (Wang and Krizakova).
In re Claim 16, Guo/Wang/Krizakova teaches the method according to Claim 15 as cited above, wherein the magnetic layer 10 (Guo, Figs. 1, 6) has an average thickness in the range of 2-5 nm - Guo teaches a thickness in a range from 1.5 nm to 10 nm (paragraph 0021) which overlaps the claimed range, and in accordance with MPEP 2144.05 Obviousness of Similar and Overlapping Ranges, Amounts, and Proportions. I. OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS, in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
In re Claim 19, Guo/Wang/Krizakova teaches the method according to Claim 15 as cited above and wherein the heavy metal layer 11 (Guo, Figs. 1, 6) has an average thickness in the range of 2-6 nm – Guo teaches a range for the thickness in a range from 1.5 nm to 10 nm (paragraph 0022), and in accordance with MPEP 2144.05 Obviousness of Similar and Overlapping Ranges, Amounts, and Proportions. I. OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS, in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
In re Claim 20, Guo/Wang/Krizakova teaches the method according to Claim 15 as cited above, wherein (Guo, Figs. 1, 4, 6, paragraph 0021) the heavy metal layer 11 has a shape corresponding to a shape of the magnetic layer 10.
Claims 5-6, 8, and 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Guo/Wang/Krizakova in view of Garello et al. (US 2020/0203598).
In re Claims 5 and 17, Guo/Wang/Krizakova teaches the MTJ device according to Claim 1 and a method of manufacturing the MTJ device of Claim 15 as cited above, where the write current passes through the heavy metal layer 11 (Guo, Fig. 6, paragraphs 0030-0031). Guo further teaches (Fig. 3, paragraphs 0028-0029) that a portion of a stack of layers (of Fig. 1) is etched such that for each layer a length in a direction of a write current flow (see also Figs. 6 and paragraphs 0030-0031 on the write current flow direction) exceeds a width of a corresponding layer with a ratio of 1.5 to 3, but does not teach that a similar etching is used to shape the SOT layer structure, including its magnetic layer 10.
Garello teaches an MTJ device (Abstract) in which a SOT layer 110 (Figs. 1a, 1b) has a shape (created by a hard mask 120, Abstract) with a length of 110 (in a direction of a write current) being more than 3 times greater than a width (paragraphs 0015, 0042, 0045).
Guo/Wang/Krizakova and Garello teach analogous arts directed to an MTJ device with a SOT layer that does not need an external magnetic layer for operation, and one of ordinary skill in the art before the effective date of filing the application would have had a reasonable expectation of success in modifying the Guo/Wang/Krizakova device and the method of its manufacturing in view of the Garello device, since they are from the same field of endeavor, and Garello created a successfully operated MTJ device.
It would have been obvious for one of ordinary skill in the art before filing the application to modify the Guo/Wang/Krizakova device of Claim 1 and the method of its manufacturing per Claim 15 by shaping a SOT layer structure (including the magnetic layer), per Garello, to have a length, in the direction of the write current, more than 3 times larger than its width (in the orthogonal direction), when such modification is beneficial for SOT-controlled switching (Garello, paragraph 0005).
In re Claims 6 and 18, Guo/Wang/Krizakova/Garello teaches the MTJ device according to Claim 5 and the method of manufacturing the MTJ device of Claim 17 as cited above, wherein, as shown for Claims 5 and 17, a length-to-width ratio of the magnetic layer is 3:1 or greater.
In re Claim 8, Guo/Wang/Krizakova teaches the MTJ device according to Claim 1 as cited above, but does not teach that the SOT layer structure further includes a topological insulator layer including a material selected from the group consisting of BixSe₁-ₓ, BixSb1-x, and (Bi, Sb)₂Te₃.
Garello teaches that a SOT layer 110 (Fig. 1, paragraphs 0037-0038) comprises a combination of layers including a topological insulator chosen from a group consisting from BixSe₁-ₓ, BixSb1-x, and (Bi, Sb)₂Te₃.
It would have been obvious for one of ordinary skill in the art before filing the application to modify the Guo/Wang/Krizakova device of Claim 1 by incorporating into its SOT layer structure a topological insulator chosen from the group consisting of BixSe₁-ₓ, BixSb1-x, and (Bi, Sb)₂Te₃, when desired: “It has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice”, In re Leshin, 125 USPQ 416.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Guo/Wang/Krizakova in view of Gupta et al. (US 2022/0189523).
In re Claim 14, Guo/Wang/Krizakova teaches the MTJ device according to Claim 1 as cited above, but does not teach (at least, explicitly) the device comprising a plurality of MTJ elements, wherein the SOT layer structure is common to the plurality of MTJ elements.
Gupta teaches an MTJ device (Abstract) comprised of a plurality of MTJ elements 41, 42 (Figs. 1a, 1b, paragraphs 0088, 0089) disposed on a common SOT layer structure 30 (paragraph 0086).
Guo/Wang/Krizakova and Gupta teach analogous arts directed to the MTJ device comprised an MTJ stack disposed on a SOT layer structure, and one of ordinary skill in the art before the effective date of filing the application would have had a reasonable expectation of success in modifying the Guo/Wang/Krizakova device in view of the Gupta device, since they are from the same field of endeavor, and Gupta created a successfully operated device.
It would have been obvious for one of ordinary skill in the art before the effective date of filing the application to modify the Guo/Wang/Krizakova MTJ device to comprise to plurality of MTJ elements, all on the same SOT layer structure, wherein it is desirable to have a structure comprised more than one MTJ elements.
Response to Arguments
Applicant arguments (REMARKS, filed 08/17/26 have been fully considered.
Examiner agrees with the Applicant that the amendments of Claims 1 and 15 in a manner suggested by the Final Rejection removes grounds for rejecting these claims under 35 U.S.C. 112(b).
Agreeing with the Applicant that the amended independent Claims 1 and 15 have some new limitations that cannot be rejected using the prior arts cited by the Final Rejection (REMARKS, pages 5-6), Examiner does not view these new limitations as new in the art – the current Office Action shows that the amended Claims 1 and 15 can be rejected by new combinations of prior arts.
As the current Office Action shows, dependent claims of the application are also obvious over the referenced prior arts (REMARKS, pages 6-7).
Conclusion
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/GALINA G YUSHINA/Primary Patent Examiner, Art Unit 2811, TC 2800,
United States Patent and Trademark Office
E-mail: galina.yushina@USPTO.gov
Phone: 571-270-7440
Date: 09/11/26
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