Detail 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 .
Status of Claims
The following is in response to the communication filed 4/29/2024.
Claims 1-20 are currently pending.
Claims 1-20 have been examined.
Priority
Applicant' s claim for the benefit of prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, or 365(c) is acknowledged. Acknowledgment is made of applicant’s claim for foreign priority under 35 USC 119(a) of Korean Patent Application No. 10-2023-0165280 filed on November 24, 2023 in the Korean Intellectual Property Office and Japanese Patent Application No. 2023-077596 filed on May 10, 2023 in the Japan Patent Office. Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statements (IDS) submitted on 4/29/2024, are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement has been considered by the examiner.
Specification
The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed.
The following title is suggested:
MAGNETORESISTIVE DEVICES AND SEMICONDUCTOR DEVICES INCLUDING A SPIN ORBIT TORQUE ELECTRODE AND FIRST MAGNETIC LAYER WITH DIFFERENT ROTATIONAL SYMMETRIES
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1, 6, 7, 10-12, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Lin US 20210359199 A1 (hereinafter Lin) in view of Lee et al. US 20230180625 A1 (hereinafter Lee) and Le US 20230047223 A1 (hereinafter Le).
Regarding claim 1, Lin US 20210359199 A1
A magnetoresistive device (Lin, Abstract, SOT-MTJ structure)comprising:
a spin orbit torque (SOT) electrode layer; (Fig 1, SOT induction structure 10)
a metal oxide layer on the SOT electrode layer; (Fig. 1, [0038], spacer layer 20A, which includes a metal oxide.)
a first nonmagnetic layer on the metal oxide layer; and (Fig. 1, [0038], spacer layer 20B, metal oxide made from a non-ferromagnetic metal such as Hf.)
a magnetic tunnel junction element (MTJ stack) including
a first magnetic layer on the first nonmagnetic layer, (Fig. 1, free layer 30 on spacer 20B, [0029] made of CoFeB.)
a second nonmagnetic layer on the first magnetic layer, and (Fig. 1, barrier layer 40, [0030] made of magnesium oxide (MgO).)
a second magnetic layer on the second nonmagnetic layer, (reference layer 50, [0031], made of a combination of Co, Fe, and B.)
…
the metal oxide layer including metal oxide, ([0038] made of a metal oxide).
Lin does not appear to disclose, “the SOT electrode layer including BiSb,” “the first nonmagnetic layer at least partially including an amorphous material,” or “a crystal included in the SOT electrode layer and a crystal included in the first magnetic layer have different rotational symmetries to a stacking direction thereof.”
However, Lee which teaches a MRAM MTJ device (Lee, Abstract), discloses that Hf
the first nonmagnetic layer (Fig. 2, metal oxide pattern 130, [0031] which includes Hf.) at least partially including an amorphous material, ([0035] the metal oxide pattern 130 has an amorphous phase.)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Lin to have the first nonmagnetic layer at least partially including an amorphous material as taught by Lee for purposes of inhibiting/preventing the crystal structure from the adjacent layers from being transferred to other adjacent layers. (Lee, [0035].)
Lin and Lee do not appear to disclose, “the SOT electrode layer including BiSb,” or “a crystal included in the SOT electrode layer and a crystal included in the first magnetic layer have different rotational symmetries to a stacking direction thereof.”
However, Le which teaches spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices, discloses:
the SOT electrode layer (Fig. 3A, a BiSb layer 304, [0026], SOT-MTJ comprising a bismuth antimony layer) including BiSb,
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Lin and Lee to have the SOT electrode layer including BiSb as taught by Le for purposes of giant spin Hall effect and high electrical conductivity. (Le, [0002].)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have a the device of Lin as modified by Lee and Le, to have a crystal included in the SOT electrode layer and a crystal included in the first magnetic layer have different rotational symmetries to a stacking direction thereof. Bismuth antimony (BiSb) of the SOT electrode is known to have three-fold rotational symmetry and CoFeB of the first magnetic layer is known to have four-fold rotational symmetry. Therefore, STO electrode layer and the first magnetic layer have different rotational symmetries.
Regarding claim 6, Lin, Lee, and Le disclose all the elements of claim 1.
Lin discloses a metal oxide layer (Lin, [0038], spacer layer 20 may be a metal oxide such MgO). The metal oxide layer would by necessity have a spin diffusion length as part of the layers material property. The SOT electrode layer and the first magnetic layer would by necessity each have a spin diffusion length as a material property of the layers. While it would be inherent for the material to have an spin diffusion length, the material property of spin diffusion length is dependent on at least the thickness of the layer. Lin does not disclose the specific spin diffusion length of any of the layers in particular. To the extent understood by the Examiner, there is no evidence of criticality of spin diffusion length in the specification of the metal layer being longer than a distance between the SOT electrode layer and the first magnetic layer. It would have been obvious to one of ordinary skill in the art at the claims were effectively filed to choose a specific thickness of the metal oxide layer in order to have a spin diffusion length that is longer than the distance of the SOT electrode layer and first magnetic layer of the based distances of those two layers. The functional requirements of the spin diffusion length would have been determinable based on the limited choices given regarding the materials used to allow for fast transport of electrons through the various layers.
Regarding claim 7, Lin, Lee, and Le disclose all the elements of claim 1.
Lin further discloses:
the first magnetic layer includes a crystal with a four-fold rotational symmetry, and (Lin, Fig. 1, free layer 30 on spacer 20B, [0029] made of CoFeB. CoFeB is known to have four-fold rotational symmetry.)
Le further discloses:
the SOT electrode layer includes a crystal with three-fold rotational symmetry. (Bismuth antimony (BiSb) of the SOT electrode is known to have three-fold rotational)
Regarding claim 10, Lin, Lee, and Le disclose all the elements of claim 1.
Lee further discloses:
the first nonmagnetic layer at least partially includes an amorphous metal. (Fig. 2, metal oxide pattern 130, [0035] the metal oxide pattern 130 has an amorphous phase.)
Regarding claim 11, Lin, Lee, and Le disclose all the elements of claim 1.
the first nonmagnetic layer includes at least one of a single transition metal, an alloy of transition metals, a compound of a transition metal and a semimetal, a transition metal nitride, a transition metal oxide, or a B-C-N based material. ( Lin, Fig. 1, free layer 30 on spacer 20B, [0029] made of CoFeB. Which includes an transition metal Fe and is a B based material.)
Regarding claim 12, Lin, Lee, and Le disclose all the elements of claim 10.
Lee further discloses:
a thickness of the first nonmagnetic layer is 0.8 nm to 1.0 nm. ([0038], the metal oxide has a range between 1 Å to 10 Å (.1nm to 1nm).)
Regarding claim 20, Lin, Lee, and Le disclose all the elements of claim 1,
Lin further discloses:
comprising a base layer, (Fig. 1, buffer layer 7)
wherein the SOT electrode layer (SOT induction structure 10) is on the base layer (buffer layer 7).
Claims 8 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Lin, Lee, and Le as applied to claim 1 above, and further in view of Hashimoto US 20190088304 A1 (hereinafter Hashimoto).
Regarding claim 8, Lin, Lee, and Le disclose all the elements of claim 1.
Lin discloses a metal oxide layer. However, neither Lin, Lee, and Le appear to disclose that the metal oxide layer contains Cr2O3.
Hashimoto, which teaches a magnetic memory device (Hashimoto, Abstract), discloses the use of Cr2O3. (Hashimoto, Fig. 1A, [0124].) It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Lin, Lee, and Le to have Cr2O3 used as metal oxide in a magnetoresistive device as taught by Hashimoto for purposes of effectively transfer the spin torque by the appropriate material. (Hashimoto, [0124].)
Regarding claim 9, Lin, Lee, Le, and Hashimoto, disclose all the elements of claim 8.
Lin, Lee, Le, and Hashimoto do not appear to teach that the thickness of the metal oxide layer is 0.5 nm to 2.5 nm specifically.
However, Lin discloses that the total spacer layer 20 which includes spacer layer 20A (i.e. the metal oxide layer of claim 1) and spacer layer 20B (i.e. first nonmagnetic layer 20B). (Lin, [0037].) This spacer layer 20 would have total thickness between 2Å – 13 Å (.2 nm to 1.3nm). (Lin, [0039]). Therefore one the metal oxide layer (spacer layer 20A) would have a thickness being some portion of the total thickness within the range disclosed by Lin. The total thickness of the spacer layer 20 would be determine by the minimum thickness necessary to reduce the exchange coupling of the free layer (i.e. first magnetic layer of claim 1) and the SOT induction structure (i.e. SOT electrode layer of claim 1). (Lin, [0039]) Therefore, the ordinary artisan would have recognized the claimed thickness range to be a result effective variable. Thus, it would have been obvious that the device of Lin as modified by Lee and Le discloses within the claimed range, since optimum or workable ranges of such variables are discoverable through routine experimentation. see MPEP 2144.05 II.B
Allowable Subject Matter
Claims 2-5 and 13-19 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
Regarding claim 2, Lin, Lee, and Le disclose all the elements of claim 1.
The cited prior art of record does not teach or fairly suggest, along with the other claimed features, a semiconductor device comprising "further comprising a third magnetic layer between the metal oxide layer and the first nonmagnetic layer, wherein the third magnetic layer is magnetically coupled to the first magnetic layer”.
Closest prior art is Apalkov et al. US 20180219152 A1, which teaches magnetic layers 182 and 186 in Fig. 5 which have high perpendicular magnetic anisotropy (PMA) that may be include of CoPt (111). However, the selection layer 182 of Apalkov is part to the free layer 162’ in the MTJ. While CoPt has been used as a magnetic layer in different areas of SOT-MRAM devices, it has not been used in the specific location of the device as claimed by claim 2. Therefore, Apalkov does not show "further comprising a third magnetic layer between the metal oxide layer and the first nonmagnetic layer, wherein the third magnetic layer is magnetically coupled to the first magnetic layer" which are layers outside of the MTJ element as described by the claim.
Claims 3-5, and 13-19 are indicated as allowable based on their dependence to claim 2.
Prior Art Made of Record
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Apalkov et al. US 20240023458 A1 – Fig. 1, spin-orbit torque magnetic random-access memory (SOT-MRAM) device with multiple metal oxides on the spin-orbit torque electrode.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to HEIM KIRIN GREWAL whose telephone number is (703)756-1515. The examiner can normally be reached Monday - Thursday 9:30 a.m. - 5:30 p.m. EST.
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/HEIM KIRIN GREWAL/ Examiner, Art Unit 2812
/DAVIENNE N MONBLEAU/ Supervisory Patent Examiner, Art Unit 2812
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