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 .
Information Disclosure Statement
The information disclosure statement (IDS) filed on April 23, 2026 has been considered by the examiner.
Status of the Claims
Claim 6 is currently amended. Claims 1-20 are present for examination.
Response to Arguments
Applicant’s arguments, see pages 8-14, filed June 23, 2026, with respect to the rejection(s) of claim(s) 1 under 35 U.S.C. 102(a)(1) have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Dieny (US 2022/0085285 A1).
Applicant’s arguments, see pages 12-14, filed June 23, 2026, with respect to the rejection(s) of claim(s) 6 under 35 U.S.C. 102(a)(1) have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Lee (US 2021/0367143 A1).
In the interest of compact prosecution, the Examiner suggests the Applicant more clearly define either (I) and/or (II)
(I) which material the SOT line configured for spin-orbit torque (SOT) is formed of (e.g. wherein the SOT line may be formed from either (i) multilayer alloys of two or more materials of tungsten (W), platinum (Pt), terbium (Tb), bismuth (Bi), selenium (Se), hafnium (Hf), zirconium (Zr), silver (Ag), gold (Au), or silicon (Si), or (ii) topological insulators of BiTe, BiSe, TlBiTe, TlBiSe, SbTeS, BiTeS, BiTeSe, GeSbTe, SnSbTe, GeBiTe, SnBiTe, BiSb, or BiSbSe; Instant Application, [0065]).
(II) further define the perpendicular shape anisotropy (PSA) design (e.g. wherein the perpendicular shape anisotropy (PSA) design further includes a dual spin filtering (DSF) structure; Instant Application, [0065])
The Examiner is available at the number below for an interview to discuss ideas at the Applicant’s convenience.
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 1-2 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Kim (US 2020/0251650 A1) in view of Dieny (US 2022/0085285 A1).
Claim 1, Kim discloses a memory device (magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6), comprising:
a magnetic tunnel junction (MTJ) structure (unit memory cell MC further includes a MTJ structure 100, [0038], Annotated Fig. 6) comprising perpendicular anisotropy (100 comprises perpendicular magnetic anisotropy, [0039], Annotated Fig. 6), and the MTJ structure 100 further comprising:
a reference layer (pinned layer 110 is a reference layer, [0039 – 0040], Annotated Fig. 6) comprising a first side and a second side that is opposite the first side of the reference layer (bottom surface of 110 is the first side of 110 and the top surface of 110 is the second side of 110, Annotated Fig. 6);
a non-magnetic spacer (tunnel barrier layer 130 is a non-magnetic spacer, [0042], Annotated Fig. 6) comprising a first side and a second side (analogous to 110_1/110_2 of 110 in Annotated Fig. 6, bottom surface of 130 is the first side, hereinafter 130_1, and the top surface of 130 is the second side, hereinafter 130_2, Annotated Fig. 6), the first side of the non-magnetic spacer 130_1 being on the second side of the reference layer 110_2 (130_1 is on 110_2, Annotated Fig. 6); and
free layer (free layer 120, [0042], Annotated Fig. 6) comprising a first side and a second side (analogous to 110 (and 130) in Annotated Fig. 6, bottom surface of 120 as well as the bottom surface of first magnetic layer 122 are the first side of 120, hereinafter 120_1, [0052], Annotated Fig. 6, and the top surface of 120 as well as the top surface of the second magnetic layer 124 are the second side of 120, hereinafter 120_2, [0056], Annotated Fig. 6), the first side of the free layer 120_1 being on the second side of the non-magnetic spacer 130_2 (120_1 is on 130_2, (i.e. 122 is on 130), Annotated Fig. 6), the free layer 120 further comprising a first layer on the first side of the free layer 110_1 (first magnetic layer 122 is a first layer on 110_1, [0052], Annotated Fig. 6), a second layer on the second side of the free layer 110_2 (second magnetic layer 124 is a second layer on 110_2, [0056], Annotated Fig. 6) and a coupling layer (coupling layer 126, [0062], Annotated Fig. 6) disposed between the first layer 122 and the second layer 124 (126 is disposed between 122 and 124, [0062], Annotated Fig. 6).
Kim does not explicitly disclose a ratio of a saturation magnetization MsFL2 of the second layer to a saturation magnetization MsFL1 of the first layer ranging from 0.2 to 0.8 inclusive.
However, Kim discloses a first magnetic layer 122 (mapped to MSFL1) which may have a first saturation magnetization (i.e. MSFL1) of 1200-500 emu/cc in [0052] and a second magnetic layer 124 (mapped to MSFL2) which may have the second saturation magnetization (i.e. MSFL2) of 500 emu/cc or less in [0058]. Therefore, the ratio of the saturation magnetization of the second layer MSFL2 to the first layer MSFL1 may be provided by forming a ratio of saturation magnetization of the second layer MSFL2 to the first layer MSFL1, wherein that resultant ratio of saturation magnetization may be between 0.2 to 0.8, inclusive (i.e. saturation magnetization of the second layer MSFL2 500 emu/cc or less : saturation magnetization of the first layer MSFL1 1200-500 emu/cc). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to vary, through routine experimentation, “the result effective variable of ratio of saturation magnetization of the second layer to the first layer (result effective at least insofar as magnetization controls the operation speed of a magnetic memory device as there in an advantage in specific TMR ratios, [0054]) in order to optimize the functionality of the device (In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955), see MPEP §2144.05).
Further, the specification contains no disclosure of either the critical nature of the claimed ratio of saturation magnetization of the second layer to the first layer or any unexpected results arising therefrom and it has been held that where patentability is said to be based upon a particular chosen dimension or upon another variable recited in a claim, the Applicant must show that the chosen dimension is critical. In re Woodruff, 919 F.2d 1575, 1578, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990).
Kim does not explicitly disclose a magnetic tunnel junction (MTJ) structure comprising perpendicular shape anisotropy.
However, Dieny discloses a magnetic tunnel junction (MTJ) structure (Dieny, spintronic device 200 has a magnetic tunnel junction (MTJ) structure, hereinafter, MTJ structure 200, [0062], Figs. 2a and 2b; Kim, unit memory cell MC further includes a MTJ structure 100, [0038], Annotated Fig. 6) comprising perpendicular shape anisotropy (Dieny, MTJ structure 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b; Kim, 100 comprises perpendicular magnetic anisotropy, [0039], Annotated Fig. 6). The combination to utilize a perpendicular shape anisotropy spin torque magnetic random access memory (PSA-ST-MRAM) in combination with a magnetic tunnel junction (MTJ) structure would enable the resultant memory device to function as either (i) a perpendicular shape anisotropy spin transfer torque magnetic random access memory point (PSA-STT-MRAM) or (ii) a perpendicular shape anisotropy spin orbit torque random access memory point (PSA-SOT-MRAM) to increase the thermal stability of the storage layer and thus extend the scalability of the memory points (Dieny, [0013]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a perpendicular shape anisotropy spin torque magnetic random access memory (PSA-ST-MRAM) in combination with a magnetic tunnel junction (MTJ) structure to enable the resultant memory device to function as either (i) a perpendicular shape anisotropy spin transfer torque magnetic random access memory point (PSA-STT-MRAM) or (ii) a perpendicular shape anisotropy spin orbit torque random access memory point (PSA-SOT-MRAM) to increase the thermal stability of the storage layer and thus extend the scalability of the memory points (Dieny, [0013]).
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Annotated Fig. 6 (Kim) – Illustrates a reference layer 110 comprising a first side 110_1 and a second side 110_2 that is opposite the first side 110_1 of the reference layer 110, wherein the second side 110_2 of the reference layer 110 is in contact with the first side 130_1 of the non-magnetic spacer 130
Claim 2, Kim/Dieny discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 1.
Kim/Dieny discloses wherein a thickness of the first layer is substantially equal to a thickness of the second layer (Kim, 122 has a thickness that may be 5 nm or less, [0052], and is substantially equal to a thickness of 124 when 124 has a thickness that is 5 nm or less, [0058], Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b).
Claim 11, Kim/Dieny discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 1.
Kim/Dieny discloses further comprising an array of the MTJ structures (Kim, cell array 1 is composed of MTJ 100 within each memory cell MC, [0038], Figs. 2 and 3; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Kim in view of Dieny, and further in view of Lill (US 2022/0131071 A1).
Claim 3, Kim/Dieny discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 1.
Kim/Dieny does not explicitly disclose wherein a ratio of a thickness of the free layer to a critical dimension of the MTJ structure is between 0.5 and 5.0 inclusive, and wherein the critical dimension of the MTJ structure ranges from 4-22 nm inclusive.
However, Lill discloses wherein a ratio of a thickness of the free layer to a critical dimension of the MTJ structure (i.e. height-to-width aspect ratio of a patterned MRAM stack) is between 0.5 and 5.0 inclusive (Lill, height-to-width aspect ratio of 5:1 (i.e. 5.0), [0054], Fig. 1; Kim, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b), and wherein the critical dimension of the MTJ structure ranges from 4-22 nm inclusive (Lill, when the height-to-width aspect ratio of 5:1 (i.e. 5.0) is maintained – a pitch between adjacent stacks may be between 10 nm – 22 nm, [0054], Figs. 1 and 2; Kim, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b). The combination of utilizing a specific critical dimension in combination with the specific aspect ratio ensures increased device density (Lill, [0028]). Further, the magnetization properties of the magnetic material stack is thickness dependent and remains a constraint in device design.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a specific critical dimension in combination with the specific aspect ratio ensures increased device density (Lill, [0028]).
Claims 4, 6, 12, 14, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Kim in view of Dieny, and further in view of Lee (US 2021/0367143 A1).
Claim 4, Kim/Dieny discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 1.
Kim/Dieny discloses wherein the first layer 122 comprises CoFeB (Kim, 122 comprises CoFeB, [0052], Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b).
Kim/Dieny does not explicitly disclose wherein the second layer comprises CoFeX or CoFeBX in which X is a diluent element comprising vanadium (V), molybdenum (Mo), titanium (Ti), zirconium (Zr), hafnium (Hf), aluminum (Al), niobium (Nb), tantalum (Ta), chromium (Cr), rhodium (Rh) or bismuth (Bi).
However, Lee discloses wherein either free layer comprises CoFeX or CoFeBX in which X is a diluent element comprising vanadium (V), molybdenum (Mo), titanium (Ti), zirconium (Zr), hafnium (Hf), aluminum (Al), niobium (Nb), tantalum (Ta), chromium (Cr), rhodium (Rh) or bismuth (Bi) (Lee, either free layer comprises a combination of (I) cobalt iron (CoFe) or cobalt iron boron (CoFeB) and (II) tantalum (Ta), molybdenum (Mo), chromium (Cr), [0030], Figs. 4A-4C; Kim, Figs. 1-3 and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b). The combination to utilize a known ferromagnetic materials in combination with non-ferromagnetic materials is known in the art for constructing a multilayer magnetic stack of materials with a desired resultant magnetism (Lee, [0030]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize known ferromagnetic materials in combination with non-ferromagnetic materials is known in the art for constructing a multilayer magnetic stack of materials with a desired resultant magnetism (Lee, [0030]).
Claim 6, Kim/Dieny discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 1.
Kim/Dieny does not explicitly disclose wherein the MTJ structure is formed on a spin-orbit torque (SOT) line having a width greater than a critical dimension of the MTJ structure.
However, Lee (US 2021/0367143 A1) discloses wherein the MTJ structure (Lee, MTJ structure 100, [0026], Figs. 1 and 23; Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) is formed on a spin-orbit torque (SOT) line (Lee, MTJ structure 100 is formed on a spin-orbit torque (SOT) line 20 (i.e. spin hall electrode 10), [0026], Figs. 1 and 23; Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) having a width greater than a critical dimension of the MTJ structure (Lee, spin-orbit torque (SOT) line 20 has a width greater than a critical dimension of the MTJ structure 100, [0026], Figs. 1 and 23; Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b). The combination to utilize a spin-orbit torque (SOT) line having a width greater than a critical dimension of the MTJ structure would enable utilization of spin-orbital-transfer (or spin-orbital-torque) (SOT) magnetic switching in the resultant semiconductor memory device, such that it has the potential to provide order-of-magnitude improvement on write current and speed and has promising applications for high-speed, low power memory cache (Lee, [0016]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a spin-orbit torque (SOT) line having a width greater than a critical dimension of the MTJ structure to enable utilization of spin-orbital-transfer (or spin-orbital-torque) (SOT) magnetic switching in the resultant semiconductor memory device, such that it has the potential to provide order-of-magnitude improvement on write current and speed and has promising applications for high-speed, low power memory cache (Lee, [0016]).
Claim 12, Kim discloses a memory device (magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6), comprising:
a magnetic tunnel junction (MTJ) structure (unit memory cell MC further includes a MTJ structure 100, [0038], Annotated Fig. 6), and the MTJ structure 100 further comprising:
a reference layer (pinned layer 110 is a reference layer, [0039 – 0040], Annotated Fig. 6) comprising a first side and a second side that is opposite the first side of the reference layer (bottom surface of 110 is the first side of 110 and the top surface of 110 is the second side of 110, Annotated Fig. 6);
a non-magnetic spacer (tunnel barrier layer 130 is a non-magnetic spacer, [0042], Annotated Fig. 6) comprising a first side and a second side (analogous to 110_1/110_2 of 110 in Annotated Fig. 6, bottom surface of 130 is the first side, hereinafter 130_1, and the top surface of 130 is the second side, hereinafter 130_2, Annotated Fig. 6), the first side of the non-magnetic spacer 130_1 being on the second side of the reference layer 110_2 (130_1 is on 110_2, Annotated Fig. 6); and
free layer (free layer 120, [0042], Annotated Fig. 6) comprising a first side and a second side (analogous to 110 (and 130) in Annotated Fig. 6, bottom surface of 120 as well as the bottom surface of first magnetic layer 122 are the first side of 120, hereinafter 120_1, [0052], Annotated Fig. 6, and the top surface of 120 as well as the top surface of the second magnetic layer 124 are the second side of 120, hereinafter 120_2, [0056], Annotated Fig. 6), the first side of the free layer 120_1 being on the second side of the non-magnetic spacer 130_2 (120_1 is on 130_2, (i.e. 122 is on 130), Annotated Fig. 6), the free layer 120 further comprising a first layer on the first side of the free layer 110_1 (first magnetic layer 122 is a first layer on 110_1, [0052], Annotated Fig. 6), a second layer on the second side of the free layer 110_2 (second magnetic layer 124 is a second layer on 110_2, [0056], Annotated Fig. 6) and a coupling layer (coupling layer 126, [0062], Annotated Fig. 6) disposed between the first layer 122 and the second layer 124 (126 is disposed between 122 and 124, [0062], Annotated Fig. 6), a saturation magnetization MsFL2 of the second layer being substantially equal to a saturation magnetization MsFL1 of the first layer (a ratio of saturation magnetization of MsFL2:MsFL1 is substantially equal when MsFL1 and MsFL2 are approximately equal (i.e. 500 emu/cc MsFL2 : 500 emu/cc MsFL1 = 1), [0052] and [0058], Annotated Fig. 6).
Kim does not explicitly disclose a magnetic tunnel junction (MTJ) structure comprising perpendicular shape anisotropy.
However, Dieny (US 2022/0085285 A1) discloses a magnetic tunnel junction (MTJ) structure (Dieny, spintronic device 200 has a magnetic tunnel junction (MTJ) structure, hereinafter, MTJ structure 200, [0062], Figs. 2a and 2b; Kim, unit memory cell MC further includes a MTJ structure 100, [0038], Annotated Fig. 6) comprising perpendicular shape anisotropy (Dieny, MTJ structure 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b; Kim, 100 comprises perpendicular magnetic anisotropy, [0039], Annotated Fig. 6). The combination to utilize a perpendicular shape anisotropy spin torque magnetic random access memory (PSA-ST-MRAM) in combination with a magnetic tunnel junction (MTJ) structure would enable the resultant memory device to function as either (i) a perpendicular shape anisotropy spin transfer torque magnetic random access memory point (PSA-STT-MRAM) or (ii) a perpendicular shape anisotropy spin orbit torque random access memory point (PSA-SOT-MRAM) to increase the thermal stability of the storage layer and thus extend the scalability of the memory points (Dieny, [0013]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a perpendicular shape anisotropy spin torque magnetic random access memory (PSA-ST-MRAM) in combination with a magnetic tunnel junction (MTJ) structure to enable the resultant memory device to function as either (i) a perpendicular shape anisotropy spin transfer torque magnetic random access memory point (PSA-STT-MRAM) or (ii) a perpendicular shape anisotropy spin orbit torque random access memory point (PSA-SOT-MRAM) to increase the thermal stability of the storage layer and thus extend the scalability of the memory points (Dieny, [0013]).
Kim does not explicitly disclose a ratio of a thickness of the first layer to a thickness of the second layer ranging from 2 to 4 inclusive.
However, Lee discloses a ratio of a thickness of the first layer (Lee, first magnetic layer FL1 is coupled to the second magnetic layer FL2, [0030], Figs. 4A-4C; Kim, first layer 122 and second layer 124, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) to a thickness of the second layer ranging from 2 to 4 inclusive (Lee, the first magnetic layer FL1 may be between about 0.5 nm – 2.5 nm thick and the second magnetic layer FL2 may be about 1.0 nm – 2.5 nm thick, [0032], the ratio of a thickness of free layer 1 to free layer 2 (i.e. t – thickness of free layer, tFL1 : tFL2) may range from 2 (i.e. tFL1 = 2.0 nm : tFL2 = 1.0 nm) to 2.5 (i.e. tFL1 = 2.5 nm : tFL2 = 1.0 nm), Figs. 4A-4C; Kim, first layer 122 and second layer 124, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b). The combination to utilize a thickness ratio of the thickness of the first magnetic free layer to the thickness of the second magnetic free layer would allow for magnetic material stacks of various crystallographic structures (i.e. specific materials) to modify resultant magnetic coupling interactions (Lee, [0030]). Further, the resultant magnetization anisotropy of the magnetic multilayer free layer structure improves switching speed and reducing write errors of the magnetic free layer as well as reduces the switching current needed to reorient the magnetization (Worledge, [0008]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a thickness ratio of the thickness of the first magnetic free layer to the thickness of the second magnetic free layer would allow for magnetic material stacks of various crystallographic structures (i.e. specific materials) to modify resultant magnetic coupling interactions (Lee, [0030]). Further, the resultant magnetization anisotropy of the magnetic multilayer free layer structure improves switching speed and reducing write errors of the magnetic free layer as well as reduces the switching current needed to reorient the magnetization (Worledge, [0008]).
Claim 14, Kim/Dieny/Lee discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b; Lee, Figs. 4A-4C) of claim 12.
Kim/Dieny/Lee discloses wherein the first layer comprises CoFeB (Kim, first layer 122 comprises CoFeB, [0052], Annotated Fig. 6; Lee, Figs. 4A-4C; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b), and
wherein the second layer comprises CoFeX or CoFeBX in which X is a diluent element comprising vanadium (V), molybdenum (Mo), titanium (Ti), zirconium (Zr), hafnium (Hf), aluminum (Al), niobium (Nb), tantalum (Ta), chromium (Cr), rhodium (Rh) or bismuth (Bi) (Lee, either free layer comprises a combination of (I) cobalt iron (CoFe) or cobalt iron boron (CoFeB) and (II) tantalum (Ta), molybdenum (Mo), chromium (Cr), [0030], Figs. 4A-4C; Kim, Figs. 1-3 and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b).
Claim 16, Kim/Dieny/Lee discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b; Lee, Figs. 4A-4C) of claim 12.
Kim/Dieny/Lee discloses further comprising a capping layer on the second side of the free layer (Kim, capping layer 140 is on the second side of free layer 120_2, [0069], Annotated Fig. 6; Lee, capping layer 70, [0036], Fig. 1; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) comprising one or more of magnesium oxide (MgO), tantalum oxide (TaO), niobium oxide (NiO), iridium oxide (IrO), sodium oxide (NaO), rhodium oxide (Rho), or osmium oxide (OsO) (Kim, 140 may include at least one of magnesium oxide (MgO), wherein obvious combinations thereof include tantalum oxide (TaO), [0070], Annotated Fig. 6; Lee, capping layer 70, [0036], Fig. 1; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Kim in view of Dieny, and further in view of Diao (US 2022/0367099 A1).
Claim 5, Kim/Dieny discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 1.
Kim/Dieny discloses does not explicitly disclose wherein the coupling layer comprises a resistance area product ranging from 0.1 to 3.0 Ωµm2 inclusive, and wherein the coupling layer comprises a tunnel magnetoresistance (TMR) that is greater than 30%.
However, Diao discloses wherein the coupling layer comprises a resistance area product ranging from 0.1 to 3.0 Ωµm2 inclusive, and wherein the coupling layer comprises a tunnel magnetoresistance (TMR) that is greater than 30% (Diao, resistance area product of 0.4 Ωµm2 and TMR is greater than 30%, [0079], Fig. 10A; Kim, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b). The combination of utilizing a material layer with a specific resistance area product and TMR value is crucial to the functionality of the resultant magnetic multilayer stack (Diao, [0004]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a material layer with a specific resistance area product and TMR value is crucial to the functionality of the resultant magnetic multilayer stack (Diao, [0004]).
Claims 7-10 are rejected under 35 U.S.C. 103 as being unpatentable over Kim in view of Dieny, and further in view of Worledge (US 2020/0152699 A1).
Claim 7, Kim/Dieny discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 1.
Kim/Dieny discloses wherein the first layer comprises a first side and a second side that is opposite the first side of the first layer (Kim, bottom surface of 122 is the first side of 122, hereinafter 122_1, and the top surface of 122 is the second side of 122, hereinafter 122_2, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) and the second layer comprising a first side and a second side that is opposite the second side of the second layer (Kim, bottom surface of 124 is the first side of 124, hereinafter 124_1, and the top surface of 124 is the second side of 124, hereinafter 124_2, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b).
Kim/Dieny does not explicitly disclose the first layer further comprising a first sublayer, a second sublayer and a first texture blocking layer disposed between the first sublayer and the second sublayer, the first sublayer being disposed distal to the coupling layer, and the second sublayer being disposed proximate to the coupling layer, and
wherein the second layer comprises a first side and a second side that is opposite the second side of the second layer, the second layer further comprising a third sublayer, a fourth sublayer and a second texture blocking layer disposed between the third sublayer and the fourth sublayer, the third sublayer being disposed proximate to the coupling layer and the fourth sublayer being disposed distal to the coupling layer.
However, Worledge discloses the first layer (Worledge, first magnetic free layer 36, [0022], Fig. 3; Kim, first layer 122, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) further comprising a stack of magnetic materials whose magnetization can be changed, such a stack of magnetic materials as each free layer within the MTJ stack would utilize a similar substructure as that of the main MTJ stack. When formed of a magnetic multilayer stack, the first layer further includes a first sublayer, a second sublayer and a first texture blocking layer disposed between the first sublayer and the second sublayer (Worledge, first magnetic free layer 36 is formed of a multilayer of materials that may have the orientation of their magnetization manipulated, further requiring a first texture blocking layer, hereinafter TBL_1, disposed between the first and second sublayers, [0022], Fig. 3; Kim, first layer 122, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b), the first sublayer being disposed distal to the coupling layer, and the second sublayer being disposed proximate to the coupling layer (Worledge, first sublayer of first magnetic free layer 36, hereinafter 36_1, is disposed distal (i.e. away from) to the coupling layer 38 while the second sublayer of first magnetic free layer 36, hereinafter 36_2, is disposed proximate (i.e. close to) to the coupling layer 38, [0025], Fig. 3; Kim, first layer 122 and coupling layer 126, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b), and
wherein the second layer (Worledge, second magnetic free layer 40, [0026], Fig. 3; Kim, second layer 124, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) comprises a first side and a second side that is opposite the second side of the second layer (Worledge, second magnetic free layer 40 comprises a first side, hereinafter 40_1 and a second side, hereinafter 40_2, wherein 40_1 is opposite of 40_2, [0026], Fig. 3; Kim, second layer 124, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b). When formed of a magnetic multilayer stack, the second layer further includes a third sublayer, a fourth sublayer and a second texture blocking layer disposed between the third sublayer and the fourth sublayer (Worledge, second magnetic free layer 40 is formed of a multilayer of materials that may have the orientation of their magnetization manipulated, further requiring a second texture blocking layer, hereinafter TBL_2, disposed between the first and second sublayers, [0025], Fig. 3; Kim, second layer 124, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b), the third sublayer being disposed proximate to the coupling layer and the fourth sublayer being disposed distal to the coupling layer (Worledge, third sublayer of second magnetic free layer 40, hereinafter 40_3, is disposed proximate (i.e. close to) to the coupling layer 38 while the fourth sublayer of second magnetic free layer 40, hereinafter 40_4, is disposed distal (i.e. away from) to the coupling layer 38, [0025], Fig. 3; Kim, first layer 122 and coupling layer 126, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b). The combination of substituting each single free layer in an MTJ stack for a multilayer magnetic material stack substantially reduces the switching current needed to reorient the magnetization of the two magnetic free layers (Abstract, Worledge).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to substitute a single free layer in an MTJ stack for a multilayer magnetic material stack substantially reduces the switching current needed to reorient the magnetization of the two magnetic free layers (Abstract, Worledge).
Claim 8, Kim/Dieny/Worledge discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Worledge, Fig. 3; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 7.
Kim/Dieny/Worledge disclose wherein at least one of the second sublayer and the third sublayer comprises a CoFe or a Heusler material (Kim, either magnetic free layer may be a Heusler material, [0053] and [0059], Figs. 1-3, and Annotated Fig. 6; Worledge, second sublayer 36_2 and third sublayer 40_3 comprises a CoFe material, [0022], Fig. 3; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b).
Claim 9, Kim/Dieny/Worledge discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b; Worledge, first magnetic free layer 36, [0022], Fig. 3) of claim 1.
Kim/Dieny/Worledge discloses disclose wherein the first layer (Worledge, first magnetic free layer 36, [0022], Fig. 3; Kim, first layer 122, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) comprises a first side and a second side that is opposite the first side of the first layer (Worledge, first side of magnetic free layer 36_S1 is opposite to the second side of magnetic free layer 36_S2, [0022], Fig. 3; Kim, first side of first layer 122_1 is opposite to the second side of first layer 122_2, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b), the first layer further comprising a first sublayer and a second sublayer, the first sublayer being disposed proximate to the non-magnetic spacer, and the second sublayer being disposed distal to the non-magnetic spacer (Worledge, first sublayer of first magnetic free layer 36, hereinafter 36_1, is disposed proximate (i.e. close to) to the non-magnetic spacer 38 while the second sublayer of first magnetic free layer 36, hereinafter 36_2, is disposed distal (i.e. away from) to the non-magnetic spacer 38, [0025], Fig. 3; Kim, first layer 122 and non-magnetic spacer 126, Annotated Fig. 6; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b), and wherein the reference layer further comprises a first layer on the first side of the reference layer and a second layer on the second side of the reference layer (Kim, reference layer 110 further comprises third magnetic layer 112 is a first layer on the first side of 110, [0080], Annotated Fig. 6; Worledge, magnetic reference layer 30 may be arranged as alternating layers in a multilayer stack, [0020], Fig. 3; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b), the second layer of the reference layer comprising a third sublayer and a fourth sublayer (Kim, reference layer 110 further comprises third magnetic layer 112 which is a first layer on the first side of 110, as well as the first nonmagnetic layer 116 as the third sublayer and fourth magnetic layer 114 as the fourth sublayer, respectively, [0080], Annotated Fig. 6; Worledge, magnetic reference layer 30 may be arranged as alternating layers in a multilayer stack, [0020], Fig. 3; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b), the third sublayer being distal to the non-magnetic spacer and the fourth sublayer being proximate to the non-magnetic spacer (Kim, third sublayer 116 is distal (i.e. away from) to the non-magnetic spacer 130 and fourth sublayer 114 is proximate (i.e. close to) to the non-magnetic spacer 130, respectively, [0080], Annotated Fig. 6; Worledge, magnetic reference layer 30 may be arranged as alternating layers in a multilayer stack, [0020], Fig. 3; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b).
Claim 10, Kim/Dieny/Worledge discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Worledge, Fig. 3; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 9.
Kim/Dieny/Worledge discloses wherein at least one of the second sublayer and the third sublayer comprises a CoFe or a Heusler material (Kim, [0053] and [0059], Figs. 1-3, and Annotated Fig. 6; Worledge, second sublayer 36_2 comprises a CoFe material, [0022], Fig. 3; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Kim in view of Dieny in view of Lee, and further in view of Lill.
Claim 13, Kim/Dieny/Lee discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Lee, Figs. 4A-4C; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 12.
Kim/Dieny/Lee does not explicitly disclose wherein a ratio of a thickness of the free layer to a critical dimension of the MTJ structure is between 0.5 and 5.0 inclusive, and wherein the critical dimension of the MTJ structure ranges from 4-22 nm inclusive.
However, Lill (US 2022/0131071 A1) discloses wherein a ratio of a thickness of the free layer to a critical dimension of the MTJ structure (i.e. height-to-width aspect ratio of a patterned MRAM stack) is between 0.5 and 5.0 inclusive (Lill, height-to-width aspect ratio of 5:1 (i.e. 5.0), [0054], Fig. 1; Kim, Annotated Fig. 6; Lee, Figs. 4A-4C; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b), and wherein the critical dimension of the MTJ structure ranges from 4-22 nm inclusive (Lill, when the height-to-width aspect ratio of 5:1 (i.e. 5.0) is maintained – a pitch between adjacent stacks may be between 10 nm – 22 nm, [0054], Figs. 1 and 2; Kim, Annotated Fig. 6; Lee, Figs. 4A-4C; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b). The combination of utilizing a specific critical dimension in combination with the specific aspect ratio ensures increased device density (Lill, [0028]). Further, the magnetization properties of the magnetic material stack is thickness dependent and remains a constraint in device design.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a specific critical dimension in combination with the specific aspect ratio ensures increased device density (Lill, [0028]).
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Kim in view of Dieny in view of Lee, and further in view of Diao.
Claim 15, Kim/Dieny/Lee discloses the memory device (Kim, magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6; Lee, Figs. 4A-4C; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 12.
Kim/Dieny/Lee does not explicitly disclose wherein the coupling layer comprises a resistance area product ranging from 0.1 to 3.0 Ωµm2 inclusive, and wherein the coupling layer comprises a tunnel magnetoresistance (TMR) that is greater than 30%.
However, Diao discloses wherein the coupling layer comprises a resistance area product ranging from 0.1 to 3.0 Ωµm2 inclusive, and wherein the coupling layer comprises a tunnel magnetoresistance (TMR) that is greater than 30% (Diao, resistance area product of 0.4 Ωµm2 and TMR is greater than 30%, [0079], Fig. 10A; Kim, Annotated Fig. 6; Lee, Figs. 4A-4C; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b). The combination of utilizing a material layer with a specific resistance area product and TMR value is crucial to the functionality of the resultant magnetic multilayer stack (Diao, [0004]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a material layer with a specific resistance area product and TMR value is crucial to the functionality of the resultant magnetic multilayer stack (Diao, [0004]).
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over Kim in view of Dieny in view of Worledge, and further in view of Lee.
Claim 17, Kim discloses a memory device (magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6), comprising:
a magnetic tunnel junction (MTJ) structure (unit memory cell MC further includes a MTJ structure 100, [0038], Annotated Fig. 6), and the MTJ structure 100 further comprising:
a reference layer (pinned layer 110 is a reference layer, [0039 – 0040], Annotated Fig. 6) comprising a first side and a second side that is opposite the first side of the reference layer (bottom surface of 110 is the first side of 110 and the top surface of 110 is the second side of 110, Annotated Fig. 6);
a non-magnetic spacer (tunnel barrier layer 130 is a non-magnetic spacer, [0042], Annotated Fig. 6) comprising a first side and a second side (analogous to 110_1/110_2 of 110 in Annotated Fig. 6, bottom surface of 130 is the first side, hereinafter 130_1, and the top surface of 130 is the second side, hereinafter 130_2, Annotated Fig. 6), the first side of the non-magnetic spacer 130_1 being on the second side of the reference layer 110_2 (130_1 is on 110_2, Annotated Fig. 6); and
free layer (free layer 120, [0042], Annotated Fig. 6) comprising a first side and a second side (analogous to 110 (and 130) in Annotated Fig. 6, bottom surface of 120 as well as the bottom surface of first magnetic layer 122 are the first side of 120, hereinafter 120_1, [0052], Annotated Fig. 6, and the top surface of 120 as well as the top surface of the second magnetic layer 124 are the second side of 120, hereinafter 120_2, [0056], Annotated Fig. 6), the first side of the free layer 120_1 being on the second side of the non-magnetic spacer 130_2 (120_1 is on 130_2, (i.e. 122 is on 130), Annotated Fig. 6), the free layer 120 further comprising a first layer on the first side of the free layer 110_1 (first magnetic layer 122 is a first layer on 110_1, [0052], Annotated Fig. 6), a second layer on the second side of the free layer 110_2 (second magnetic layer 124 is a second layer on 110_2, [0056], Annotated Fig. 6) and a coupling layer (coupling layer 126, [0062], Annotated Fig. 6) disposed between the first layer 122 and the second layer 124 (126 is disposed between 122 and 124, [0062], Annotated Fig. 6), a saturation magnetization MsFL2 of the second layer being substantially equal to a saturation magnetization MsFL1of the first layer (a ratio of saturation magnetization of MsFL2:MsFL1 is substantially equal when MsFL1 and MsFL2 are approximately equal (i.e. 500 emu/cc MsFL2 : 500 emu/cc MsFL1 = 1), [0052] and [0058], Annotated Fig. 6).
the first layer 122 comprising a first side and a second side that is opposite the first side of the first layer (bottom surface of 122 is the first side of 122, hereinafter 122_1, and the top surface of 122 is the second side of 122, hereinafter 122_2, Annotated Fig. 6) and the second layer comprising a first side and a second side that is opposite the second side of the second layer (bottom surface of 124 is the first side of 124, hereinafter 124_1, and the top surface of 124 is the second side of 124, hereinafter 124_2, Annotated Fig. 6), and
at least one of the second sublayer and the third sublayer comprises a CoFe or a Heusler material (Kim, [0053] and [0059], Figs. 1-3, and Annotated Fig. 6; Worledge, second sublayer 36_2 comprises a CoFe material, [0022], Fig. 3).
Kim does not explicitly disclose the first layer further comprising a first sublayer, a second sublayer and a first texture blocking layer disposed between the first sublayer and the second sublayer, the first sublayer being disposed distal to the coupling layer, and the second sublayer being disposed proximate to the coupling layer, and
the second layer further comprising a third sublayer, a fourth sublayer and a second texture blocking layer disposed between the third sublayer and the fourth sublayer, the third sublayer being disposed proximate to the coupling layer and the fourth sublayer being disposed distal to the coupling layer.
However, Worledge discloses the first layer (Worledge, first magnetic free layer 36, [0022], Fig. 3; Kim, first layer 122, Annotated Fig. 6) further comprising a stack of magnetic materials whose magnetization can be changed, such a stack of magnetic materials as each free layer within the MTJ stack would utilize a similar substructure as that of the main MTJ stack. When formed of a magnetic multilayer stack, the first layer further includes a first sublayer, a second sublayer and a first texture blocking layer disposed between the first sublayer and the second sublayer (Worledge, first magnetic free layer 36 is formed of a multilayer of materials that may have the orientation of their magnetization manipulated, further requiring a first texture blocking layer, hereinafter TBL_1, disposed between the first and second sublayers, [0022], Fig. 3; Kim, first layer 122, Annotated Fig. 6), the first sublayer being disposed distal to the coupling layer, and the second sublayer being disposed proximate to the coupling layer (Worledge, first sublayer of first magnetic free layer 36, hereinafter 36_1, is disposed distal (i.e. away from) to the coupling layer 38 while the second sublayer of first magnetic free layer 36, hereinafter 36_2, is disposed proximate (i.e. close to) to the coupling layer 38, [0025], Fig. 3; Kim, first layer 122 and coupling layer 126, Annotated Fig. 6), and
the second layer (Worledge, second magnetic free layer 40, [0026], Fig. 3; Kim, second layer 124, Annotated Fig. 6) comprising a magnetic multilayer stack, the second layer further includes a third sublayer, a fourth sublayer and a second texture blocking layer disposed between the third sublayer and the fourth sublayer (Worledge, second magnetic free layer 40 is formed of a multilayer of materials that may have the orientation of their magnetization manipulated, further requiring a second texture blocking layer, hereinafter TBL_2, disposed between the first and second sublayers, [0025], Fig. 3; Kim, second layer 124, Annotated Fig. 6), the third sublayer being disposed proximate to the coupling layer and the fourth sublayer being disposed distal to the coupling layer (Worledge, third sublayer of second magnetic free layer 40, hereinafter 40_3, is disposed proximate (i.e. close to) to the coupling layer 38 while the fourth sublayer of second magnetic free layer 40, hereinafter 40_4, is disposed distal (i.e. away from) to the coupling layer 38, [0025], Fig. 3; Kim, first layer 122 and coupling layer 126, Annotated Fig. 6). The combination of substituting each single free layer in an MTJ stack for a multilayer magnetic material stack substantially reduces the switching current needed to reorient the magnetization of the two magnetic free layers (Abstract, Worledge).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to substitute a single free layer in an MTJ stack for a multilayer magnetic material stack substantially reduces the switching current needed to reorient the magnetization of the two magnetic free layers (Abstract, Worledge).
Kim/Worledge does not explicitly disclose a ratio of a thickness of the first layer to a thickness of the second layer ranging from 2 to 4 inclusive.
However, Lee discloses a ratio of a thickness of the first layer (Lee, first magnetic layer FL1 is coupled to the second magnetic layer FL2, [0030], Figs. 4A-4C; Kim, first layer 122 and second layer 124, Annotated Fig. 6; Worledge, Fig. 3) to a thickness of the second layer ranging from 2 to 4 inclusive (Lee, the first magnetic layer FL1 may be between about 0.5 nm – 2.5 nm thick and the second magnetic layer FL2 may be about 1.0 nm – 2.5 nm thick, [0032], the ratio of a thickness of free layer 1 to free layer 2 (i.e. t – thickness of free layer, tFL1 : tFL2) may range from 2 (i.e. tFL1 = 2.0 nm : tFL2 = 1.0 nm) to 2.5 (i.e. tFL1 = 2.5 nm : tFL2 = 1.0 nm), Figs. 4A-4C; Kim, first layer 122 and second layer 124, Annotated Fig. 6; Worledge, Fig. 3). The combination to utilize a thickness ratio of the thickness of the first magnetic free layer to the thickness of the second magnetic free layer would allow for magnetic material stacks of various crystallographic structures (i.e. specific materials) to modify resultant magnetic coupling interactions (Lee, [0030]). Further, the resultant magnetization anisotropy of the magnetic multilayer free layer structure improves switching speed and reducing write errors of the magnetic free layer as well as reduces the switching current needed to reorient the magnetization (Worledge, [0008]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a thickness ratio of the thickness of the first magnetic free layer to the thickness of the second magnetic free layer would allow for magnetic material stacks of various crystallographic structures (i.e. specific materials) to modify resultant magnetic coupling interactions (Lee, [0030]). Further, the resultant magnetization anisotropy of the magnetic multilayer free layer structure improves switching speed and reducing write errors of the magnetic free layer as well as reduces the switching current needed to reorient the magnetization (Worledge, [0008]).
Kim/Lee/Worledge does not explicitly disclose a magnetic tunnel junction (MTJ) structure comprising perpendicular shape anisotropy.
However, Dieny (US 2022/0085285 A1) discloses a magnetic tunnel junction (MTJ) structure (Dieny, spintronic device 200 has a magnetic tunnel junction (MTJ) structure, hereinafter, MTJ structure 200, [0062], Figs. 2a and 2b Lee, first magnetic layer FL1 is coupled to the second magnetic layer FL2, [0030], Figs. 4A-4C; Kim, first layer 122 and second layer 124, Annotated Fig. 6; Worledge, Fig. 3) comprising perpendicular shape anisotropy (Dieny, MTJ structure 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b; Lee, first magnetic layer FL1 is coupled to the second magnetic layer FL2, [0030], Figs. 4A-4C; Kim, first layer 122 and second layer 124, Annotated Fig. 6; Worledge, Fig. 3). The combination to utilize a perpendicular shape anisotropy spin torque magnetic random access memory (PSA-ST-MRAM) in combination with a magnetic tunnel junction (MTJ) structure would enable the resultant memory device to function as either (i) a perpendicular shape anisotropy spin transfer torque magnetic random access memory point (PSA-STT-MRAM) or (ii) a perpendicular shape anisotropy spin orbit torque random access memory point (PSA-SOT-MRAM) to increase the thermal stability of the storage layer and thus extend the scalability of the memory points (Dieny, [0013]).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Kim in view of Dieny in view of Worledge in view of Lee, and further in view of Lill.
Claim 18, Kim/Lee/Worledge/Dieny discloses the memory device (Kim, Figs. 1-3 and Annotated Fig. 6; Lee, Figs. 4A-4C; Worledge, Fig. 3; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 17.
Kim/Lee/Worledge/Dieny does not explicitly disclose wherein a ratio of a thickness of the free layer to a critical dimension of the MTJ structure is between 0.5 and 5.0 inclusive, and wherein the critical dimension of the MTJ structure ranges from 4-22 nm inclusive.
However, Lill discloses wherein a ratio of a thickness of the free layer to a critical dimension of the MTJ structure (i.e. height-to-width aspect ratio of a patterned MRAM stack) is between 0.5 and 5.0 inclusive (Lill, height-to-width aspect ratio of 5:1 (i.e. 5.0), [0054], Fig. 1; Kim, Annotated Fig. 6; Lee, Figs. 4A-4C; Worledge, Fig. 3; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b), and wherein the critical dimension of the MTJ structure ranges from 4-22 nm inclusive (Lill, when the height-to-width aspect ratio of 5:1 (i.e. 5.0) is maintained – a pitch between adjacent stacks may be between 10 nm – 22 nm, [0054], Figs. 1 and 2; Kim, Annotated Fig. 6; Lee, Figs. 4A-4C; Worledge, Fig. 3; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b). The combination of utilizing a specific critical dimension in combination with the specific aspect ratio ensures increased device density (Lill, [0028]). Further, the magnetization properties of the magnetic material stack is thickness dependent and remains a constraint in device design.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a specific critical dimension in combination with the specific aspect ratio ensures increased device density (Lill, [0028]).
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Kim in view of Dieny in view of Lee in view of Worledge, and further in view of Kalitsov (US 2021/0320245 A1).
Claim 19, Kim discloses a memory device (magnetic memory device, [0027], Figs. 1-3, and Annotated Fig. 6), comprising:
a magnetic tunnel junction (MTJ) structure (unit memory cell MC further includes a MTJ structure 100, [0038], Annotated Fig. 6), and the MTJ structure 100 further comprising:
a reference layer (pinned layer 110 is a reference layer, [0039 – 0040], Annotated Fig. 6) comprising a first side and a second side that is opposite the first side of the reference layer (bottom surface of 110 is the first side of 110 and the top surface of 110 is the second side of 110, Annotated Fig. 6), the reference layer further comprises a first layer on the first side of the reference layer and a second layer on the second side of the reference layer (Kim, reference layer 110 further comprises third magnetic layer 112 is a first layer on the first side of 110, [0080], Annotated Fig. 6; Worledge, magnetic reference layer 30 may be arranged as alternating layers in a multilayer stack, [0020], Fig. 3), the second layer of the reference layer comprising a first sublayer and a second sublayer (Kim, reference layer 110 further comprises third magnetic layer 112 which is a first layer on the first side of 110, as well as the first nonmagnetic layer 116 as the first sublayer and fourth magnetic layer 114 as the second sublayer, respectively, [0080], Annotated Fig. 6; Worledge, magnetic reference layer 30 may be arranged as alternating layers in a multilayer stack, [0020], Fig. 3), and the second sublayer being distal to the first side of the reference layer and proximate to the second side of the reference layer (Kim, second sublayer 114 is distal to 110_1 and proximate to 110_2, respectively, [0080], Annotated Fig. 6; Worledge, magnetic reference layer 30 may be arranged as alternating layers in a multilayer stack, [0020], Fig. 3);
a non-magnetic spacer (tunnel barrier layer 130 is a non-magnetic spacer, [0042], Annotated Fig. 6) comprising a first side and a second side (analogous to 110_1/110_2 of 110 in Annotated Fig. 6, bottom surface of 130 is the first side, hereinafter 130_1, and the top surface of 130 is the second side, hereinafter 130_2, Annotated Fig. 6), the first side of the non-magnetic spacer 130_1 being on the second side of the reference layer 110_2 (130_1 is on 110_2, Annotated Fig. 6); and
free layer (free layer 120, [0042], Annotated Fig. 6) comprising a first side and a second side (analogous to 110 (and 130) in Annotated Fig. 6, bottom surface of 120 as well as the bottom surface of first magnetic layer 122 are the first side of 120, hereinafter 120_1, [0052], Annotated Fig. 6, and the top surface of 120 as well as the top surface of the second magnetic layer 124 are the second side of 120, hereinafter 120_2, [0056], Annotated Fig. 6), the first side of the free layer 120_1 being on the second side of the non-magnetic spacer 130_2 (120_1 is on 130_2, (i.e. 122 is on 130), Annotated Fig. 6), the free layer 120 further comprising a first layer on the first side of the free layer 110_1 (first magnetic layer 122 is a first layer on 110_1, [0052], Annotated Fig. 6), a second layer on the second side of the free layer 110_2 (second magnetic layer 124 is a second layer on 110_2, [0056], Annotated Fig. 6) and a coupling layer (coupling layer 126, [0062], Annotated Fig. 6) disposed between the first layer 122 and the second layer 124 (126 is disposed between 122 and 124, [0062], Annotated Fig. 6), a saturation magnetization MsFL2 of the second layer being substantially equal to a saturation magnetization MsFL1 of the first layer (a ratio of saturation magnetization of MsFL2:MsFL1 is substantially equal when MsFL1 and MsFL2 are approximately equal (i.e. 500 emu/cc MsFL2 : 500 emu/cc MsFL1 = 1), [0052] and [0058], Annotated Fig. 6), and
at least one of the second sublayer and the third sublayer comprises a CoFe or a Heusler material (either magnetic free layer may be a Heusler material, [0053] and [0059], Figs. 1-3, and Annotated Fig. 6).
Kim does not explicitly disclose a ratio of a thickness of the first layer to a thickness of the second layer ranging from 2 to 4 inclusive.
However, Lee discloses a ratio of a thickness of the first layer (Lee, first magnetic layer FL1 is coupled to the second magnetic layer FL2, [0030], Figs. 4A-4C; Kim, first layer 122 and second layer 124, Annotated Fig. 6) to a thickness of the second layer ranging from 2 to 4 inclusive (Lee, the first magnetic layer FL1 may be between about 0.5 nm – 2.5 nm thick and the second magnetic layer FL2 may be about 1.0 nm – 2.5 nm thick, [0032], the ratio of a thickness of free layer 1 to free layer 2 (i.e. t – thickness of free layer, tFL1 : tFL2) may range from 2 (i.e. tFL1 = 2.0 nm : tFL2 = 1.0 nm) to 2.5 (i.e. tFL1 = 2.5 nm : tFL2 = 1.0 nm), Figs. 4A-4C; Kim, first layer 122 and second layer 124, Annotated Fig. 6). The combination to utilize a thickness ratio of the thickness of the first magnetic free layer to the thickness of the second magnetic free layer would allow for magnetic material stacks of various crystallographic structures (i.e. specific materials) to modify resultant magnetic coupling interactions (Lee, [0030]). Further, the resultant magnetization anisotropy of the magnetic multilayer free layer structure improves switching speed and reducing write errors of the magnetic free layer as well as reduces the switching current needed to reorient the magnetization (Worledge, [0008]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a thickness ratio of the thickness of the first magnetic free layer to the thickness of the second magnetic free layer would allow for magnetic material stacks of various crystallographic structures (i.e. specific materials) to modify resultant magnetic coupling interactions (Lee, [0030]). Further, the resultant magnetization anisotropy of the magnetic multilayer free layer structure improves switching speed and reducing write errors of the magnetic free layer as well as reduces the switching current needed to reorient the magnetization (Worledge, [0008]).
Kim/Lee does not explicitly disclose the first layer comprising a first side and a second side that is opposite the first side of the first layer, the first layer further comprising a third sublayer and a fourth sublayer, the third sublayer being disposed proximate to the non-magnetic spacer, and the fourth sublayer being disposed distal to the non-magnetic spacer.
However, Kim/Lee/Worledge disclose the first layer (Worledge, first magnetic free layer 36, [0022], Fig. 3; Kim, first layer 122, Annotated Fig. 6; Lee, Figs. 4A-4C) comprising a first side and a second side that is opposite the first side of the first layer (Worledge, first side of magnetic free layer 36_S1 is opposite to the second side of magnetic free layer 36_S2, [0022], Fig. 3; Kim, first side of first layer 122_1 is opposite to the second side of first layer 122_2, Annotated Fig. 6; Lee, Figs. 4A-4C). The combination to layer adjacent materials in an MTJ stack for a multilayer magnetic material stack substantially reduces the switching current needed to reorient the magnetization of the two magnetic free layers (Abstract, Worledge).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to substitute a single free layer in an MTJ stack for a multilayer magnetic material stack substantially reduces the switching current needed to reorient the magnetization of the two magnetic free layers (Abstract, Worledge).
Kim/Lee/Worledge does not explicitly disclose the first layer further comprising a third sublayer and a fourth sublayer, the third sublayer being disposed proximate to the non-magnetic spacer, and the fourth sublayer being disposed distal to the non-magnetic spacer.
However, Kalitsov discloses the first layer (Kalitsov, magnetic tunnel junction 140 is further composed of a first layer 133/132/25D, Fig. 11; Kim, Figs. 1-3 and Annotated Fig. 6; Worledge, Fig. 3; Lee, Figs. 4A-4C) further comprising a third sublayer and a fourth sublayer (third sublayer 25D and fourth sublayer 133, [0185], Fig. 11; Kim, Figs. 1-3 and Annotated Fig. 6; Worledge, Fig. 3; Lee, Figs. 4A-4C), the third sublayer being disposed proximate to the non-magnetic spacer (third sublayer 25D being disposed proximate to the non-magnetic spacer 23D, [0185], Fig. 11; Kim, Figs. 1-3 and Annotated Fig. 6; Worledge, Fig. 3; Lee, Figs. 4A-4C), and the fourth sublayer being disposed distal to the non-magnetic spacer (Kalitsov, fourth sublayer 133 being disposed distal to the non-magnetic spacer 23D, [0185], Fig. 11; Kim, Figs. 1-3 and Annotated Fig. 6; Worledge, Fig. 3; Lee, Figs. 4A-4C). The combination of adding additional sublayers within the magnetization structure allows for utilization of the perpendicular magnetic anisotropy of the materials in the magnetization stack (Kalitsov, [0169]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to add additional sublayers within the magnetization structure allows for utilization of the perpendicular magnetic anisotropy of the materials in the magnetization stack (Kalitsov, [0169]).
Kim/Lee/Worledge/Kalitsov does not explicitly disclose a magnetic tunnel junction (MTJ) structure comprising perpendicular shape anisotropy.
However, Dieny (US 2022/0085285 A1) discloses a magnetic tunnel junction (MTJ) structure (Dieny, spintronic device 200 has a magnetic tunnel junction (MTJ) structure, hereinafter, MTJ structure 200, [0062], Figs. 2a and 2b; Kalitsov, magnetic tunnel junction 140 is further composed of a first layer 133/132/25D, Fig. 11; Kim, Figs. 1-3 and Annotated Fig. 6; Worledge, Fig. 3; Lee, Figs. 4A-4C) comprising perpendicular shape anisotropy (Dieny, MTJ structure 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b; Kalitsov, magnetic tunnel junction 140 is further composed of a first layer 133/132/25D, Fig. 11; Kim, Figs. 1-3 and Annotated Fig. 6; Worledge, Fig. 3; Lee, Figs. 4A-4C). The combination to utilize a perpendicular shape anisotropy spin torque magnetic random access memory (PSA-ST-MRAM) in combination with a magnetic tunnel junction (MTJ) structure would enable the resultant memory device to function as either (i) a perpendicular shape anisotropy spin transfer torque magnetic random access memory point (PSA-STT-MRAM) or (ii) a perpendicular shape anisotropy spin orbit torque random access memory point (PSA-SOT-MRAM) to increase the thermal stability of the storage layer and thus extend the scalability of the memory points (Dieny, [0013]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a perpendicular shape anisotropy spin torque magnetic random access memory (PSA-ST-MRAM) in combination with a magnetic tunnel junction (MTJ) structure to enable the resultant memory device to function as either (i) a perpendicular shape anisotropy spin transfer torque magnetic random access memory point (PSA-STT-MRAM) or (ii) a perpendicular shape anisotropy spin orbit torque random access memory point (PSA-SOT-MRAM) to increase the thermal stability of the storage layer and thus extend the scalability of the memory points (Dieny, [0013]).
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Kim in view of Dieny in view of Lee in view of Worledge in view of Kalitsov, and further in view of Lill.
Claim 20, Kim/Lee/Worledge/Kalitsov/Dieny discloses the memory device (Kim, Figs. 1-3 and Annotated Fig. 6; Lee, Figs. 4A-4C; Worledge, Fig. 3; Kalitsov, Fig. 11; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b) of claim 19.
Kim/Lee/Worledge/Kalitsov does not explicitly disclose wherein a ratio of a thickness of the free layer to a critical dimension of the MTJ structure is between 0.5 and 5.0 inclusive, and wherein the critical dimension of the MTJ structure ranges from 4-22 nm inclusive.
However, Lill discloses wherein a ratio of a thickness of the free layer to a critical dimension of the MTJ structure (i.e. height-to-width aspect ratio of a patterned MRAM stack) is between 0.5 and 5.0 inclusive (Lill, height-to-width aspect ratio of 5:1 (i.e. 5.0), [0054], Fig. 1; Kim, Annotated Fig. 6; Lee, Figs. 4A-4C; Worledge, Fig. 3; Kalitsov, Fig. 11; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b), and wherein the critical dimension of the MTJ structure ranges from 4-22 nm inclusive (Lill, when the height-to-width aspect ratio of 5:1 (i.e. 5.0) is maintained – a pitch between adjacent stacks may be between 10 nm – 22 nm, [0054], Figs. 1 and 2; Kim, Annotated Fig. 6; Lee, Figs. 4A-4C; Worledge, Fig. 3; Kalitsov, Fig. 11; Dieny, memory device 200 may comprise perpendicular shape anisotropy (PSA), [0088], Figs. 2a and 2b). The combination of utilizing a specific critical dimension in combination with the specific aspect ratio ensures increased device density (Lill, [0028]). Further, the magnetization properties of the magnetic material stack is thickness dependent and remains a constraint in device design.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to utilize a specific critical dimension in combination with the specific aspect ratio ensures increased device density (Lill, [0028]).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Ito (US 2020/0058802 A1) discloses a magnetic tunnel junction (MTJ) structure (magnetoresistance effect device, abstract) including perpendicular magnetic anisotropy (first and second portions 35A/35B have magnetic anisotropy in a direction perpendicular, [0085], Figs. 1-3) with a squareness ratio in the range of 0.5 to 1.
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
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/CHEVY J BOEGEL/Examiner, Art Unit 2812
/William B Partridge/Supervisory Patent Examiner, Art Unit 2812
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