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) submitted on 8/22/25 was filed after the mailing date of the non-final rejection on 2/24/25. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Claim Status
Previous action: 1, 3 through 10, 12, and 15 through 20 are rejected
Present action: 1, 3 through 10, 12, and 15 through 20 are rejected
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 3 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 3 recites the limitation "the second phase-change material" in line 2. There is insufficient antecedent basis for this limitation in the claim. The assumed antecedent of the element is “a second phase-change material layer’ in claim 1 line 6, however this is not correctly referenced in claim 3. The examiner will understand and suggest “the second phase-change material layer that is proximate”.
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)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(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) 10, 12, 15, and 16 is/are rejected under 35 U.S.C. 102a2 as being by Cheng (US 2023/0189667)
Regarding claim 10.
Cheng teaches:
A structure comprising: a top electrode (fig 10b:206; [para 0060,0071]) and a bottom electrode (fig 10b:806; [para 0060]);
and a multilayer stack disposed (fig 10b; [para 0071])between the top electrode (fig 10b:206; [para 0060,0071]) and the bottom electrode (fig 10b:806; [para 0060,0071]), wherein the multilayer stack (fig 10b; [para 0065,0071])comprises alternating confinement layers (fig 10b:RL; [para 0065,0071]) and phase-change material layers (fig 10b:PCM; [para 0065,0071]), wherein a first phase-change material layer (fig 10b:PCM; [para 0065,0071]) proximate to the bottom electrode (fig 10b:806; [para 0060,0071]) has a thinner thickness ([para 0071]) than a second phase-change material layer (fig 10b:PCM; [para 0065,0071]) proximate to the top electrode (fig 10b:206; [para 0060,0071]), and wherein a first confinement layer (fig 10b:RL; [para 0065,0071]) proximate to the bottom electrode (fig 10b:806; [para 0060,0071]) has a thinner thickness ([para 0071]) than a second confinement layer (fig 10b:RL; [para 0065,0071]) proximate to the top electrode (fig 10b:206; [para 0060,0071]).
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Regarding claim 12.
Cheng teaches the structure of claim 10, further
Cheng teaches:
different thicknesses ([para 0071]) of the confinement layers (fig 10b:RL; [para 0065.0071]) and the phase-change material layers (fig 10b:PCML; [para 0065,0071]) result in variable resistance through the multilayer stack (resistance is a function of thickness; [para 0065]).
Regarding claim 15.
Cheng teaches the structure of claim 10, further
Cheng teaches:
the phase-change material layers (fig 10b:PCML; [para 0065,0071]) have a similar crystallinity temperature (Tc) ([para 0065] compounds that have a similar structure, in the present case GST, will have similar properties including Tc. MPEP 2144.05.I, 2144.09.I).
Regarding claim 16.
Cheng teaches the structure of claim 10, further
Cheng teaches:
the confinement layers (fig 10b:RL; [para 0065,0071]) comprise one or more selected from a group consisting of: Ti(Se, Te)₂, Tantalum Nitride (TaN), Carbon (C), Tantalum Aluminum Nitride (TaAIN), Tantalum Silicon Nitride (TaSiN), Titanium Aluminum Nitride (TiAIN), Titanium Silicon Nitride (TiSiN), Titanium Nitride (TiN), Silicon (Si).
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.
Rejection Note: Italicized and struck through claim limitations indicate limitations that are not explicitly disclosed in the primary reference, but disclosed in the secondary reference(s) or interpreted using case law and reasoning.
Claim(s) 1, 3, 4, 5, 6, and 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hamann (US 2005/0112896) in view of Wu (US 2021/0249592)
Regarding claim 1.
Hamann teaches:
A structure comprising: a top electrode (fig 3:10; [para 0037]) and a bottom electrode (fig 3:55; [para 0037]);
and a multilayer stack (fig 3:15-35; [para 0037]) disposed between the top electrode (fig 3:10; [para 0037]) and the bottom electrode (fig 3:55; [para 0037]), wherein the multilayer stack (fig 3:15-35; [para 0037]) comprises alternating confinement layers (fig 3:20,30,40; [para 0037]) and phase-change material layers (fig 3:15,25,35,45; [para 0037]), wherein a first phase-change material layer (fig 3:25; [para 0037]) has a first doping concentration of a first dopant ([para 0029]), and wherein a second phase-change material layer (fig 3:35; [para 0037]) has a second doping concentration of a second dopant ([para 0029]), wherein the first doping concentration is different than the second doping concentration ([para 0029]),
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Hamann does not teach that the phase change layers have different dopant concentrations of different dopants.
Wu teaches:
a first phase-change material layer (fig 4c:130a; [para 0055])has a first doping concentration of a first dopant ([para 0047,0053]), and wherein a second phase-change material layer (fig 4c:130b; [para 0055])has a second doping concentration of a second dopant ([para 0047,0053]), wherein the first doping concentration is different than the second doping concentration (130a germanium + dopant = 36% to 56%, 130b germanium +dopant = 46% to 66%; [para 0047,0053]), and wherein the first dopant (germanium) is different than the second dopant (nitrogen).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to vary the concentration of the GST sublayers in order to improve the retention characteristics of the device (paragraph 48)
Regarding claim 3.
Hamann in view of Wu teaches the structure of claim 1, further
Hamann teaches:
the first phase-change material layer (fig 3:25; [para 0037]) is proximate to the bottom electrode (fig 3:55; [para 0037]) and has a higher resistance (direct relationship to height; [para 0028]) than the second phase-change material [layer] (fig 3:15; [para 0037]) that is (fig 3:10; [para 0037]).
Regarding claim 4.
Hamann in view of Wu teaches the structure of claim 1, further
Hamann teaches:
the first doping concentration and the second doping concentration result in variable resistance ([para 0029]) through the multilayer stack (fig 3:15-35; [para 0037]).
Regarding claim 5.
Hamann in view of Wu teaches the structure of claim 1, further
Hamann teaches:
the phase-change material layers (fig 3:15,25,35,45; [para 0037]) comprise a similar crystallinity temperature (Tc) (compounds that have a similar structure, in the present case GST, will have similar properties MPEP 2144.05.I, 2144.09.I).
Regarding claim 6.
Hamann in view of Wu teaches the structure of claim 1, further
Hamann teaches:
the first dopant comprises at least one dopant selected from a group consisting of: Germanium (Ge), Nitrogen (N) ([para 0029]), Silicon (Si), Selenium (Se), Tantalum (Ta), Silicon Dioxide (SiO₂), Carbon (C), and Aluminum Nitride (AIN).
Regarding claim 7.
Hamann in view of Wu teaches the structure of claim 1, further
Hamann teaches:
the confinement layers (fig 3:20,30,40; [para 0027]) comprise one or more selected from a group consisting of: Ti(Se, Te)₂, Tantalum Nitride (TaN), Carbon (C), Tantalum Aluminum Nitride (TaAIN), Tantalum Silicon Nitride (TaSiN), Titanium Aluminum Nitride (TiAIN), Titanium Silicon Nitride (TiSiN), Titanium Nitride (TiN), Silicon (Si) ([para 0027]).
Claim(s) 8 and 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hamann (US 2005/0112896) in view of Wu (US 2021/0249592) as applied to claim 1 and further in view of Gotti (US 2015/0028284)
Regarding claim 8.
Hamann in view of Wu teaches the structure of claim 1, above
Hamann in view of Wu does not teach the layer thickness
Gotti teaches:
each layer (fig 2:211,210; [para 0026,0028]) in the multilayer stack (fig 2:208; [para 0023]) has a thickness of 1-20 nanometers (nm) ([para 0026,0028]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention for each layer to be 1 to 20 nm in order to provide sufficient resistance to effectively store data as a resistance change in the material
Regarding claim 9
Hamann in view of Wu teaches the structure of claim 1, further
Gotti teaches:
the multilayer stack (fig 2:208; [para 0023]) has a thickness of 20-200 nanometers (nm) ([para 0026,0028]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention stack to have a thickness of 20-200 nm in order to provide sufficient resistance to effectively store data as a resistance change in the material
Claim(s) 17 and 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cheng (US 2023/0189667) as applied to claim 10 and further in view of Gotti (US 2015/0028284).
Regarding claim 17.
Cheng teaches the structure of claim 10, above
Cheng does not teach the layer thickness
Gotti teaches:
each layer (fig 2:211,210; [para 0026,0028]) in the multilayer stack (fig 2:208; [para 0023]) has a thickness of 1-20 nanometers (nm) ([para 0026,0028]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention for each layer to be 1 to 20 nm in order to provide sufficient resistance to effectively store data as a resistance change in the material
Regarding claim 18
Cheng teaches the structure of claim 10, further
Gotti teaches:
the multilayer stack (fig 2:208; [para 0023]) has a thickness of 20-200 nanometers (nm) ([para 0026,0028]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention stack to have a thickness of 20-200 nm in order to provide sufficient resistance to effectively store data as a resistance change in the material
Claim(s) 19 and 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Harmann (US 2005/0112896) in view of Wu (US 2021/0249592)
Regarding claim 19.
Harmann teaches:
A structure comprising: a top electrode (fig 2:10; [para 0027]) and a bottom electrode (fig 2:50; [para 0027]);
and a multilayer stack (fig 2:; [para 0027]) disposed between the top electrode (fig 2:10; [para 0027]) and the bottom electrode (fig 2:10; [para 0027]), wherein the multilayer stack (fig 2:; [para 0027]) comprises alternating confinement layers (fig 2:20,30,40; [para 0027]) and phase-change material layers (fig 2:15,25,35,45; [para 0027]), wherein a first phase-change material layer (fig 2:45; [para 0027]) has a first doping concentration of a first dopant ([para 0029]), and wherein a second phase-change material layer (fig 2:15; [para 0027]) has a second doping concentration of a second dopant ([para 0029]), wherein the first doping concentration is different than the second doping concentration ([para 0029]), , and wherein at least two of the phase-change material layers (fig 2:15,45; [para 0028]) have different thicknesses (fig 2:L1,L4; [para 0028]).
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Hamann does not teach that the phase change layers have different dopant concentrations of different dopants.
Wu teaches:
a first phase-change material layer (fig 4c:130a; [para 0055])has a first doping concentration of a first dopant ([para 0047,0053)], and wherein a second phase-change material layer (fig 4c:130b; [para 0055])has a second doping concentration of a second dopant ([para 0047,0053]), wherein the first doping concentration is different than the second doping concentration (130a germanium + dopant = 36% to 56%, 130b germanium +dopant = 46% to 66%; [para 0047,0053]), and wherein the first dopant (germanium) is different than the second dopant (nitrogen).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to vary the concentration of the GST sublayers in order to improve the retention characteristics of the device (paragraph 48)
Regarding claim 20.
Harmann in view of Wu teaches the structure of claim 19, further
Harman teaches:
the first phase-change material layer (fig 2:45; [para 0027]) is proximate to the bottom electrode (fig 2:50; [para 0027]) and has a higher resistance (fig 2:R4; [para 0028]) than the second phase-change material layer (fig 2:15; [para 0027]) that is proximate to the top electrode (fig 2:10; [para 0027]) (resistance is directly proportional to heights; [para 0028]).
Response to Arguments
Applicant’s arguments with respect to claim(s) have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
The applicant argues that Wu (US 2021/0249592) does not teach different dopant concentrations of different dopants
The applicant is incorrect. Wu clearly and explicitly teaches that the concentration of germanium (a material that the applicant states is a dopant) varies in concentration in the different layers (paragraph 53), this ranges from 35% to about 45% in layer 130a to 45% to 55% in layer 130b. Further, Wu teaches a concentration of a second different dopant of from 1% to 10% in layers 130a and 130b (paragraph 53)
The applicant will note that a concentration of 1 to 10% is different that a concentration of 45% to 55%or 45% to 55% and germanium is different than the dopant (paragraph 47)
From claim 1:
a first phase-change material layer has a first doping concentration of a first dopant,
and wherein a second phase-change material layer has a second doping concentration of a second dopant,
wherein the first doping concentration is different than the second doping concentration,
and wherein the first dopant is different than the second dopant.
The applicant argues that Hamann does not teach that the phase change layers have a similar crystallization temperature.
The applicant is incorrect. Hamann teaches that the phase change material comprises GST, GST has the property of Tc, layers comprising GST will therefore have similar properties of Tc. MPEP 2144.05.I, 2144.09.I.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DAVID J GOODWIN whose telephone number is (571)272-8451. The examiner can normally be reached Monday - Friday, 11:00 - 19:00.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Kretelia Graham can be reached at (571)272-5055. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/D.J.G/ Examiner, Art Unit 2817
/Kretelia Graham/Supervisory Patent Examiner, Art Unit 2817
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