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 .
Election/Restrictions
The Office acknowledges Applicant’s preliminary election of Invention I (claims 1–8) with traverse in the reply filed on February 2nd 2026. The grounds of traversal have been considered.
Applicant has amended claim 15 so that it now recites each and every limitation of claim 1. As a result, claims 15–20 (formerly designated as Invention III) and claims 1–8 (Invention I) are now related as combination and subcombination, as described in MPEP § 806.05(a) and further exemplified in MPEP § 806.05(C).
Therefore, the Office finds that claims 1–8 and 15–20 are not distinct and should not be restricted. Accordingly, the restriction requirement between these claims filed on February 2nd 2026 is hereby withdrawn. Claims 1–8 and 15–20 will be examined together.
Applicant is reminded that upon the cancelation of claims to a non-elected invention, the inventorship must be corrected in compliance with 37 CFR 1.48(a) if one or more of the currently named inventors is no longer an inventor of at least one claim remaining in the application. A request to correct inventorship under 37 CFR 1.48(a) must be accompanied by an application data sheet in accordance with 37 CFR 1.76 that identifies each inventor by his or her legal name and by the processing fee required under 37 CFR 1.17(i).
Additionally, new claims 21-26 will be examined as corresponding to the elected invention.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim(s) 1, 2, 15, 19, 21, 23-25 is/are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Hui-Lin Wang et al. (US 20240114803 A1) herein after referred to as “Wang”.
Regarding claim 1, Wang teaches
A magnetic tunnel junction (MTJ) structure (Fig. 7 elements, 52), comprising:
a barrier layer (46);
a free layer (Fig. 2, 4, element 92, Para. [0013] 92 is the bottom most free layer of layer 48 ), disposed on the barrier layer (Fig 2, 4, 7, element 92 is on layer 46, Para. [0013]);
and a metal oxide cap layer (Fig. 2, 4, element 96 of 48, Para. [0013]), disposed on the free layer (92), wherein the metal oxide cap layer has a first surface (bottom of 96) and a second surface (top of 96) opposite to the first surface, wherein the first surface of the metal oxide cap layer is in contact with the free layer (the bottom of 96 is in contact with 92), and wherein in a direction of a thickness of the metal oxide cap layer, both of an oxygen concentration at the first surface of the metal oxide cap layer and an oxygen concentration at the second surface of the metal oxide cap layer are higher than an oxygen concentration in a middle portion (Fig. 2 element 100) of the metal oxide cap layer. (Fig. 4 Para [0017])
Regarding claim 2, Wang teaches
The MTJ structure of claim 1, wherein the metal oxide cap layer (Fig. 2, 4, 7 element 96 of 48) comprises a lower portion (98), the middle portion (100) and an upper portion (102) arranged along the direction of the thickness of the metal oxide cap layer (96), wherein the lower portion has the first surface (bottom of 96), the upper portion has the second surface (top of 96), and an average oxygen concentration of the lower portion and an average oxygen concentration of the upper portion is higher than an average oxygen concentration of the middle portion. (Fig. 4 Para [0017])
Regarding claim 15, Wang teaches
A memory cell (Para. 1), comprising:
a first electrode (Fig. 7 elements 42) and a second electrode (50); and
a stack of a barrier layer (46), a free layer (92) disposed on (Fig. 2, 4, 7, Para. [0013]) the barrier layer, and a metal oxide cap layer (96) disposed on(Fig. 2, 4) the free layer (92), wherein the stack is disposed between the first electrode and the second electrode (Fig. 7), wherein, in a stacking direction of the stack, an oxygen concentration in the metal oxide cap layer decreases from a first surface (bottom of 96) of the metal oxide cap layer in contact with the free layer to a middle portion(100) of the metal oxide cap layer, and then increases from the middle portion of the metal oxide cap layer to a second surface (top of 96) of the metal oxide cap layer opposite to the first surface, such that both of the oxygen concentration at the first surface of the metal oxide cap layer and the oxygen concentration at the second surface of the metal oxide cap layer are higher than the oxygen concentration in the middle portion of the metal oxide cap layer in a direction of a thickness (horizontally) of the metal oxide cap layer. (Fig. 4 Para [0017])
Regarding claim 19, Wang teaches
The memory cell of claim 15, wherein the metal oxide cap layer has the oxygen concentration that gradually varies along the stacking direction (horizontally). (Fig. 4 Para [0017])
Regarding Claim 21, Wang teaches
The MTJ structure of claim 1, further comprising:
a dielectric capping layer (Fig. 7 element 56 Para.[0021]) , disposed on a sidewall of the barrier layer, a sidewall of the free layer, and a side wall of the metal oxide cap layer. (Fig.7)
Regarding Claim 23, Wang teaches
The MTJ structure of claim 1, further comprising: a reference layer (44), wherein the barrier layer(46) is disposed between(Fig 2,7, Para.[0013]) the reference layer (44) and the metal oxide cap layer (96 of 48) and the free layer (92 of 48) is disposed between the metal oxide cap layer (96 of 48) and the barrier layer(46) (Fig. 2, 4, 7).
Regarding Claim 24, Wang teaches
A magnetic tunnel junction (MTJ) structure (fig. 7 element 52), comprising: a stack of a reference layer(44), a free layer (Fig. 2, 4, 7 elements 92), and a metal oxide cap layer (96), wherein the free layer is disposed between the metal oxide cap layer and the reference layer(Para. [0013] Fig. 2, 4, 7) , the metal oxide cap layer (Para. [0013]) has a first surface (bottom of 96) and a second surface (top of 96) opposite to the first surface, the first surface of the metal oxide cap layer is in contact with the free layer (bottom of 96 is in contact with 92 Fig. 2), and wherein in a direction of a thickness (horizontally) of the metal oxide cap layer, both of an oxygen concentration at the first surface of the metal oxide cap layer and an oxygen concentration at the second surface of the metal oxide cap layer are higher than an oxygen concentration in a middle portion (Fig. 2 element 100) of the metal oxide cap layer. (Fig. 4 Para [0017])
Regarding Claim 25, Wang teaches
The MTJ structure of claim 24, wherein the metal oxide cap layer (Fig. 2 elements 96) comprises, from bottom to top, a lower portion (98), the middle portion (100), and an upper portion (102), wherein an average oxygen concentration of the middle portion is lower than an average oxygen concentration of the lower portion and an average oxygen concentration of the upper portion. (Fig. 4 Para [0017])
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.
Claim(s) 3, 4, 16, 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang as applied to claim 2 and 15 above, and further in view of Lin Xue et al. (US 10468592 B1) herein after referred to as “Xue”.
Regarding Claim 3, Wang teaches
The MTJ structure of claim 2,
(with a metal oxide layer (96) made of MgO (Para. [0013]) and teaches the importance of relative oxygen concentration (para[0026]) in the lower portion (98), middle portion (100), and upper portion (102). )
Wang does not explicitly teach
the structure of the metal oxide and does not teach an explicit numerical range of oxygen concentration
Xue teaches an MTJ stack
wherein a material of the metal oxide cap layer (Fig. 1a element 122) comprises cubic crystalline MOy, (Col. 6 lines 59-63, Col. 12-13 lines 66-2, Col. 4 lines 64-65) where M is a metallic element , O is an oxygen element,
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the device of Wang such that the material of the metal oxide cap layer comprises cubic crystalline MOy, as described in the analogous prior art of Xue because the modification allows improved lattice matching creating a MTJ stack that can withstand high temperature processes during manufacture (Col.4 line 28-33)
Neither Wang or Xue explicitly teach the Limitation
and y is in the range of 0.75 to 1 in the lower portion and the upper portion, while y is in the range of 0.5 to 0.75 in the middle portion.
Since Wang teaches, a metal oxide cap layer with an average oxygen concentration of the lower portion and an average oxygen concentration of the upper portion is higher than an average oxygen concentration of the middle portion; and Wang teaches, that this configuration of oxygen concentration allows for the device to more effectively prevent oxygen atoms in the lower barrier layer underneath from diffusing upward into the material layers above thereby affecting the performance of the device (Wang para. [0026]), it would have been obvious for a person of ordinary skill in the art to experiment to reach a concentration range that follows the teachings of Wang. Therefore, the concentration of oxygen is a result effective variable (a variable which achieves a recognized result); and this limitation will be considered as Routine Optimization. “Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical…” see MPEP § 2144.05 to learn more.
Regarding Claim 4, Wang in view of Xue teaches
The MTJ structure of claim 3,
Neither Wang or Xue explicitly teach the Limitation
wherein throughout the metal oxide cap layer, the average value of y in MOy is greater than 0.68 and less than 0.82.
However above in claim 3 it was determined that the concentration of oxygen is a result effective variable and narrowing the range of oxygen concentration does not affect that determination. Therefore, this limitation will be considered as Routine Optimization. See MPEP § 2144.05 to learn more.
Regarding Claim 16, Wang teaches
The memory cell of claim 15, wherein the metal oxide cap layer (96) comprises, from bottom to top, a lower portion(98), the middle portion(100) and an upper portion (102),
(with a metal oxide layer (96) made of MgO (Para. [0013]) and teaches the importance of relative oxygen concentration (para[0026]) in the lower portion, middle portion, and upper portion.)
Wang does not explicitly teach
the structure of the metal oxide and does not teach an explicit numerical range of oxygen concentration
Xue teaches an MTJ stack
wherein a material of the metal oxide cap layer (Fig. 1a element 122) comprises cubic crystalline MOy, (Col. 6 lines 59-63, Col. 12-13 lines 66-2, Col. 4 lines 64-65) where M is a metallic element , O is an oxygen element,
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the device of Wang such that the material of the metal oxide cap layer comprises cubic crystalline MOy, as described in the analogous prior art of Xue because the modification allows improved lattice matching creating a MTJ stack that can withstand high temperature processes during manufacture (Col.4 line 28-33)
Neither Wang or Xue explicitly teach the Limitation
and y is in the range of 0.75 to 1 in the lower portion and the upper portion, while y is in the range of 0.5 to 0.75 in the middle portion.
However above in claim 3 it was determined that the concentration of oxygen is a result effective variable and putting the MTJ stack in a memory cell between the electrodes of claim 15 does not affect that determination. Therefore, this limitation will be considered as Routine Optimization. See MPEP § 2144.05 to learn more.
Regarding Claim 17, Wang in view of Xue teaches
The memory cell of claim 16,
Neither Wang or Xue explicitly teach the Limitation
wherein throughout the metal oxide cap layer, the average value of y in MOy is greater than 0.68 and less than 0.82.
However above in claim 3 it was determined that the concentration of oxygen is a result effective variable and narrowing the range of oxygen concentration does not affect that determination. Therefore, this limitation will be considered as Routine Optimization. See MPEP § 2144.05 to learn more.
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang as applied to claim 2 above, and further in view of Eiji Kariyada et al. (US 20230180628 A1) herein after referred to as Kariyada.
Regarding Claim 5 Wang teaches
The MTJ structure of claim 2, with a lower portion(98), the middle portion(100) and an upper portion (102), (in which the lower portion and the upper portion each occupy 14.3% to 20% of a total thickness of the metal oxide cap layer, while the middle portion occupies 60% to 71.4% of the total thickness of the metal oxide cap layer.) (Para. [0015])
Wang does not teach
wherein the lower portion and the upper portion each occupy 30% to 40% of a total thickness of the metal oxide cap layer, while the middle portion occupies 20% to 40% of the total thickness of the metal oxide cap layer.
Kariyada teaches an MTJ structure
wherein the lower portion and the upper portion each occupy 30% to 40% (Para [0079] [0065] Fig 1A,1B, 6. Elements 56a and 56c. Meaning the upper and lower portions are known to be 1-2nm ) of a total thickness of the metal oxide cap layer, while the middle portion occupies 20% to 40% (Para. [0073] Fig. 4A to 4F, 1A element 56b. meaning the middle portion is known to be 0.1-1nm) of the total thickness of the metal oxide cap layer. (fig. 1a, 1b, 4a-4f, 6, 9)(For example if the lower portion and upper portion is 1.05nm(35% of the total thickness each) and the middle portion is 0.9nm(30%))
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the device of Wang such that the lower portion and the upper portion each occupy 30% to 40% of a total thickness of the metal oxide cap layer, while the middle portion occupies 20% to 40% of the total thickness of the metal oxide cap layer., as described in Kariyada because the modification allows for increase or at least the control over the level of magnetoresistance (Fig.1b, 4a-9 Para.[0035],[0039]-[0050])
Claim(s) 6, 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang as applied to claim 1 and 15 above, and further in view of Shinto Ichikawa et al. (US 20220278271 A1) Herein after referred to a “Ichikawa”.
Regarding claim 6, Wang teaches
The MTJ structure of claim 1, wherein the barrier layer(46) and the metal oxide cap layer(96) comprise a same metal oxide material,(para. [0012],[0013])
Wang does not teach
The average oxygen concentration level of the barrier layer and the metal oxide cap layer relative to each other.
Ichikawa teaches an MTJ
wherein an average oxygen concentration of the metal oxide material in the barrier layer (3) is higher than an average oxygen concentration of the metal oxide material in the metal oxide cap layer(4).(Para. [0065])
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the device of Wang such that the an average oxygen concentration of the metal oxide material in the barrier layer is higher than an average oxygen concentration of the metal oxide material in the metal oxide cap layer, as described in Ichikawa because the modification allows for the decrease of resistivity of the magnetoresistance effect on the device without decreasing the perpendicular magnetic anisotropy (Para. [0134],[0092],[0065])
Regarding claim 20 Wang teaches
The memory cell of claim 15, wherein the barrier layer(46) and the metal oxide cap layer(96) comprise a same metal oxide material,(para. [0012],[0013])
Wang does not teach
The average oxygen concentration level of the barrier layer and the metal oxide cap layer relative to each other.
Ichikawa teaches an MTJ
wherein the barrier layer(3) and the metal oxide cap layer(4) comprise a same metal oxide material(Para.[0053],[0141]) but have different average oxygen concentrations, with a resistivity of the metal oxide cap layer being lower than a resistivity of the barrier layer.(Para.[0065])
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the device of Wang such that the barrier layer and the metal oxide cap layer have different average oxygen concentrations, with a resistivity of the metal oxide cap layer being lower than a resistivity of the barrier layer as described in Ichikawa because the modification allows for the decrease of resistivity of the magnetoresistance effect on the device without decreasing the perpendicular magnetic anisotropy (Para. [0134],[0092],[0065])
Claim(s) 7, 8, 22, 26 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang as applied to claim 1, 2, and 25 above, and further in view of Ikhtiar et al. (US 20200158796 A1).
Regarding Claim 7, Wang teaches
The MTJ structure of claim 1, further comprises: a cap layer (Fig. 7 elements 82), disposed above the metal oxide cap layer (96); a reference layer (44), disposed below the barrier layer (46); a bottom electrode (42), disposed below the reference layer (44); and a top electrode (50), disposed above the cap layer (82).
Wang does not teach the cap layer be specifically metallic
Ikhtiar teaches an MTJ stack
Wherein the cap layer is a metallic cap layer (Fig. 1 element 330 Para. [0046]),
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the device of Wang such that the cap layer is a metallic cap layer, as described in Ikhtiar because the modification allows for the metal elements with higher Gibbs free energy to act as a diffusion barrier because of the elements unlikely hood of forming an oxide even in high annealing temperatures. (Ikhtiar Para. [0053]))
Regarding Claim 8, Wang in view of Ikhtiar teaches
The MTJ structure of claim 7,
Wang does not teach
a hard mask layer, disposed between the metallic cap layer and the top electrode.
Ikhtiar further teaches
further comprises: a hard mask layer, disposed between the metallic cap layer and the top electrode.(Para. [0067])
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the device of Wang such that a hard mask layer is disposed between the metallic cap layer and the top electrode, as described in Ikhtiar because the modification improves the pattering and dimension retention of the MTJ stack. (Para. [0067])
Regarding Claim 22, Wang teaches
The MTJ structure of claim 2, (with lower portion (98), middle portion(100), and upper portion(102) of the metal oxide cap layer (96))
Wang does not explicitly teach
the thickness of these layers
Ikhtiar Teaches a metal oxide cap layer
With two layers of metal oxide 310 in size range 1A-6A and 320 in size range 1A-8A (para. [0052])Therefore the limitation
wherein a thickness of the lower portion is in a range from 2A to 5A, a thickness of the upper portion is in a range from 2A to 5A, and a thickness of the middle portion is in a range from 1A to 3A.
have thickness ranges that all fall within known parameters for the thickness of metal oxide layer portions.
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the device of Wang such that the thicknesses of the lower portion and upper portion are in range 2A-5A and the middle portion is in range 1A-3A , as described in Ikhtiar because the modification allows for the formation of a desired structure of the metal oxide cap layer and the control of the level of its resistivity (Ikhtiar Para. [0054]).
Regarding claim 26, Wang teaches
The MTJ structure of claim 25, (with lower portion (98), middle portion(100), and upper portion(102) of the metal oxide cap layer (96))
Wang does not explicitly teach
the thickness of these layers
Ikhtiar Teaches a metal oxide cap layer
With two layers of metal oxide 310 in size range 1A-6A and 320 in size range 1A-8A (para. [0052]) Therefore the limitation
wherein a thickness of the lower portion is in a range from 2A to 5A, a thickness of the upper portion is in a range from 2A to 5A, and a thickness of the middle portion is in a range from 1A to 3X.
have thickness ranges that all fall within known parameters for the thickness of metal oxide layer portions.
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the device of Wang such that the thicknesses of the lower portion and upper portion are in range 2A-5A and the middle portion is in range 1A-3A , as described in Ikhtiar because the modification allows for the formation of a desired structure of the metal oxide cap layer and the control of the level of its resistivity (Ikhtiar Para. [0054]).
Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang in view of Xue as applied to claim 16 above, and further in view of Kariyada.
Regarding Claim 18, Wang in view of Xue teaches
The memory cell of claim 16, (in which the lower portion(98) and the upper portion (102) each occupy 14.3% to 20% of a total thickness of the metal oxide cap layer(96), while the middle portion(100) occupies 60% to 71.4% of the total thickness of the metal oxide cap layer. )(Para. [0015])
Wang does not teach
wherein the lower portion and the upper portion each occupy 30% to 40% of a total thickness of the metal oxide cap layer, while the middle portion occupies 20% to 40% of the total thickness of the metal oxide cap layer.
Kariyada teaches an MTJ structure
wherein the lower portion and the upper portion each occupy 30% to 40% (Para [0079] [0065] Fig 1A,1B, 6. Elements 56a and 56c. Meaning the upper and lower portions are known to be 1-2nm ) of a total thickness of the metal oxide cap layer, while the middle portion occupies 20% to 40% (Para. [0073] Fig. 4A to 4F, 1A element 56b. meaning the middle portion is known to be 0.1-1nm) of the total thickness of the metal oxide cap layer. (fig. 1a, 1b, 4a-4f, 6, 9)(for example if the lower portion and upper portion is 1.05nm(35% of the total thickness each) and the middle portion is 0.9nm(30%))
It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the device of Wang such that the lower portion and the upper portion each occupy 30% to 40% of a total thickness of the metal oxide cap layer, while the middle portion occupies 20% to 40% of the total thickness of the metal oxide cap layer., as described in Kariyada because the modification allows for increase or at least the control over the level of magnetoresistance (Fig.1b, 4a-9 Para.[0035],[0039]-[0050])
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Guo; Yimin et al. (US 20220238799 A1), SHIN; Hee Ju et al. (US 20240284802 A1).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAIME LYNN SPRENGER whose telephone number is (571)272-8444. The examiner can normally be reached Monday - Thursday, 7:30a.m. - 5:00p.m. ET..
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sue Purvis can be reached at 571-272-1236. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/JAIME LYNN SPRENGER/ Examiner, Art Unit 2893 /J.L.S./Examiner, Art Unit 2893
/SUE A PURVIS/ Supervisory Patent Examiner, Art Unit 2893