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 .
Response to Amendments
2. The Amendments filed November 21st, 2025 in response to the Non-Final Office Action mailed 05/23/2025 are noted.
Applicant’s amendments to the claims are noted.
3. Claims 13-20 are now canceled; Claims 1-12 and 21-26 remain pending in the application.
4. Claims 1-12 and 21-26 have been fully considered in examination.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-8, 12, and 21-26 are rejected under 35 U.S.C. 103 as being unpatentable over Lu (U.S. PG Pub No US2019/0131420A1) (of record) in view of Frank (U.S. PG Pub No US2020/0020762A1) (of record).
Regarding claim 1, Lu teaches a method [see title, 0055] of forming a bilayer stack [0055] for a ferroelectric tunnel junction [0025], the method comprising:
depositing a first metal oxide film (25) fig. 3A [0056] on a substrate (10) fig. 3A [0056] by performing a first plurality of cycles of atomic layer deposition [0057] (one cycle is considered to result in the deposition of one monolayer of ZrO2 – multiple layers may be deposited by repeated cycles [0057]);
depositing a second metal oxide film (30) fig. 3A [0058] on the substrate (10) by performing a second plurality of cycles of atomic layer deposition [0058, 0045] (multiple monolayers deposited by ALD), wherein the second metal oxide film (30) contains hafnium oxide and zirconium oxide (Zr-doped HfO2 / HfZrO2) [0057, 0060], wherein the second metal oxide film (30) has a different hafnium oxide and zirconium oxide content than the first (ZrO2) metal oxide film (25) (30 comprises hafnium oxide whereas 25 does not [0056, 0044-0045]; further, 30 may comprise elemental dopants [0044] such as Al [0065] in non-negligible quantities which affect relative amounts of Hf and Zr to O2 in the material, such that the chemical formula of layer 30 may be expressed as (AlZrHf)O2, with Al in 5-7 mol% [0065] - whereas 25 does not comprise a significant amount of aluminum [0056]; see also fig. 6); and
heat-treating [0059] the substrate (10) to form a ferroelectric phase in the second metal oxide film (30) ((111) orthorhombic after heating [0059, 0025]) but not in the first metal oxide film (25) (ZrO2 layer 25 thickness down 0.5 nm [0057] – which is below 1.5 nm / ferroelectric threshold thickness).
However, Lu does not explicitly disclose wherein the first metal oxide film (25) contains a first solid solution of a mixture of hafnium oxide and zirconium oxide (only zirconium oxide instead [0056]),
wherein the second metal oxide film (30) contains a second solid solution mixture of hafnium oxide and zirconium oxide.
Frank teaches a method [see title] wherein the first metal oxide film (104 lower portion) fig. 1 [0031] contains a first solid solution of a mixture of hafnium oxide and zirconium oxide (104 may be provided as a combined-mixture [0031, 0041] of hafnium and zirconium oxide [0040-0041] instead of only zirconium oxide),
wherein the second metal oxide film (104 upper portion) fig. 1 [0031] contains a second solid solution mixture of hafnium oxide and zirconium oxide (104 may be provided as a “mixture” of hafnium and zirconium oxide [0040-0041] instead of a multilayer).
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the zirconium and/or hafnium films of Lu to be provided, at least in part, as solid “mixtures” of zirconium-and-hafnium oxide [0031, 0040-0041] in order to favorably control/enhance the high-k material’s dielectric properties [0032] in the finished product(s) [0032-0035], as taught by Frank.
Regarding claim 2, Lu teaches the method [see title, 0055] of claim 1. Lu also teaches wherein the zirconium oxide content in the first metal oxide film (25) fig. 3A [0056] (HfxZryOz where x ~ 0) [0056] is below a threshold value needed for formation of the ferroelectric phase by the heat-treating (25 thickness down 0.5 nm [0057] – which is below 1.5 nm / ferroelectric threshold thickness of HfxZryOz where x ~ 0).
Regarding claim 3, Lu teaches the method [see title, 0055] of claim 1. Lu also teaches wherein the hafnium oxide content in the first metal oxide film (25) fig. 3A [0056] (HfxZryOz where x ~ 0) [0056] is below about 25 mol% (~0%).
Regarding claim 4, Lu teaches the method [see title, 0055] of claim 1. Lu also teaches wherein the hafnium oxide content and the zirconium oxide content (Zr-doped HfO2 / HfZrO2) [0057, 0060] in the second metal oxide film (30) fig. 3A [0058] is greater than about 25 mol% (may be about 50:50 Hf-oxide and Zr-oxide).
Regarding claim 5, Lu teaches the method [see title, 0055] of claim 1. Lu also teaches wherein the first metal oxide film (25) fig. 3A [0056] exhibits linear polarization in the presence of an external electric field (25 may be ZrO2 with a thickness of 0.5nm-1.0nm [0056, 0057] – which is below 1.5 nm / ferroelectric threshold thickness).
Regarding claim 6, Lu teaches the method [see title, 0055] of claim 1. Lu also teaches wherein a thickness (30 may be 1-5 nm [0055, 0045]) of the second metal oxide film (30) fig. 3A [0058] is greater than a thickness of the first metal oxide film (25) fig. 3A [0056] (which may be 0.5nm [0057]).
Regarding claim 7, Lu teaches the method [see title, 0055] of claim 1. Lu also teaches wherein a thickness of the first metal oxide film (25) fig. 3A [0056] (which may be 0.5nm [0057]) is about 1.5nm, or less.
Regarding claim 8, Lu teaches the method [see title, 0055] of claim 1. Lu also teaches wherein the depositing the first metal oxide film (25) fig. 3A [0056] further includes heat-treating [0059] the substrate (10) fig. 3A [0056] after one or more cycles of the atomic layer deposition [0057].
Regarding claim 12, Lu teaches the method [see title, 0055] of claim 1. Lu also teaches wherein heat-treating [0059] is performed at a substrate temperature between about 400C and about 900C in the presence of an inert gas ([0059, 0049] annealing may be performed at about 700C in inert gas like Ar).
Regarding claim 21, Lu teaches a method [see title, 0055] of forming a bilayer stack [0055] for a ferroelectric tunnel junction [0025], the method comprising:
depositing a first metal oxide film (25) fig. 3A [0056] on a substrate (10) fig. 3A [0056] by performing a first plurality of cycles of atomic layer deposition [0057] (one cycle is considered to result in the deposition of one monolayer of ZrO2 – multiple layers may be deposited by repeated cycles [0057]);
depositing a second metal oxide film (30) fig. 3A [0058] on the substrate (10) by performing a second plurality of cycles of atomic layer deposition [0058, 0045] (multiple monolayers deposited by ALD), wherein the second metal oxide film (30) contains hafnium oxide and zirconium oxide (Zr-doped HfO2 / HfZrO2) [0057, 0060], and wherein the second metal oxide (30) has a different composition than the first metal oxide film (25) (30 comprises hafnium oxide whereas 25 does not [0056, 0044-0045]; further, 30 may comprise elemental dopants [0044] such as Al [0065] in non-negligible quantities which affect relative amounts of Hf and Zr to oxygen in the material, such that the chemical formula of layer 30 may be expressed as (AlZrHf)O2, with Al in 5-7 mol% [0065] - whereas 25 does not comprise a significant amount of aluminum [0056]; see also fig. 6) and;
heat-treating [0059] the substrate (10) to form a ferroelectric phase in the second metal oxide film (30) ((111) orthorhombic after heating [0059, 0025]) but not in the first metal oxide film (25) (ZrO2 layer 25 thickness down 0.5 nm [0057] – which is below 1.5 nm / ferroelectric threshold thickness).
However, Lu does not explicitly disclose wherein the first metal oxide film (25) contains hafnium oxide (only zirconium oxide instead [0056]),
wherein the second metal oxide film (30) contains a second solid solution mixture of hafnium oxide and zirconium oxide.
Frank teaches a method [see title] wherein the first metal oxide film (104 lower portion) fig. 1 [0031] contains hafnium oxide and zirconium oxide (104 may be provided as a combined-mixture [0031, 0041] of hafnium and zirconium oxide [0040-0041] instead of only zirconium oxide),
wherein the second metal oxide film (104 upper portion) fig. 1 [0031] contains a second solid solution mixture of hafnium oxide and zirconium oxide (104 may be provided as a “mixture” of hafnium and zirconium oxide [0040-0041] instead of a multilayer).
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the zirconium and/or hafnium films of Lu to be provided, at least in part, as solid “mixtures” of zirconium-and-hafnium oxide [0031, 0040-0041] in order to favorably control/enhance the high-k material’s dielectric properties [0032] in the finished product(s) [0032-0035], as taught by Frank.
Regarding claim 22, Lu teaches the method [see title, 0055] of claim 21. Lu also teaches wherein the hafnium oxide content and the zirconium oxide content (Zr-doped HfO2 / HfZrO2) [0057, 0060] in the second metal oxide film (30) fig. 3A [0058] is greater than about 25 mol% (may be about 50:50 Hf-oxide and Zr-oxide).
Regarding claim 23, Lu teaches the method [see title, 0055] of claim 21. Lu also teaches wherein the first metal oxide film (25) fig. 3A [0056] exhibits linear polarization in the presence of an external electric field (25 may be ZrO2 with a thickness of 0.5nm-1.0nm [0056, 0057] – which is below 1.5 nm / ferroelectric threshold thickness).
Regarding claim 24, Lu teaches the method [see title, 0055] of claim 21. Lu also teaches wherein a thickness of the first metal oxide film (25) fig. 3A [0056] (which may be 0.5nm [0057]) is about 1.5nm, or less.
Regarding claim 25, Lu teaches the method [see title, 0055] of claim 21. Lu also teaches wherein the depositing the first metal oxide film (25) fig. 3A [0056] further includes heat-treating [0059] the substrate (10) fig. 3A [0056] after one or more cycles of the atomic layer deposition [0057].
Regarding claim 26, Lu teaches the method [see title, 0055] of claim 21. Lu also teaches wherein heat-treating [0059] is performed at a substrate temperature between about 400C and about 900C in the presence of an inert gas ([0059, 0049] annealing may be performed at about 700C in inert gas like Ar).
Claims 9-11 are rejected under 35 U.S.C. 103 as being unpatentable over Lu (U.S. PG Pub No US2019/0131420A1) (of record) modified by Frank (U.S. PG Pub No US2020/0020762A1) (of record), as applied in claim 1 above, and further in view of Ahn (U.S. PG Pub No US2008/0087890A1) (of record).
Regarding claim 9, Lu teaches the method [see title, 0055] of claim 1. Lu also teaches wherein the depositing the first/second metal oxide film (25/30) fig. 3A [0058] includes:
a) sequentially first, exposing the substrate (10) fig. 3A [0056] to a hafnium precursor (HfCl4) [0055, 0046]
b) sequentially first, exposing the substrate (10) to an oxidizer (H20) [0055, 0046]
c) sequentially first, exposing the substrate to a zirconium precursor (ZrCl4) [0055, 0046]
d) sequentially first, exposing the substrate (10) to the oxidizer (H20) [0055, 0046].
However, Lu does not explicitly disclose sequentially second, exposing the substrate (10) to a purge gas in steps a) - d).
Ahn teaches a method [see title, 0048, fig. 2] comprising:
a) sequentially first, exposing the substrate [0049] to a hafnium precursor (first precursor at block 204) fig. 2 [0050] and, sequentially second, exposing the substrate [0049] to a purge gas (at block 206) fig. 2 [0051];
b) sequentially first, exposing the substrate [0049] to an oxidizer (at block 208) fig. 2 [0052] and, sequentially second, exposing the substrate [0052] to the purge gas (at block 210) fig. 2 [0053];
c) sequentially first, exposing the substrate [0052] to a zirconium precursor (second precursor at block 214) fig. 2 [0055] and, sequentially second, exposing the substrate [0055] to the purge gas (at lock 216) fig. 2 [0056]; and
d) sequentially first, exposing the substrate [0057] to the oxidizer (at block 218) fig. 2 [0057] and, sequentially second, exposing the substrate to the purge gas (at block 220) fig. 2 [0058].
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the ALD method of Lu to include a purging process after exposing the substrate to each precursor and oxidant [0051-0061] in order to remove byproducts and excess reactants [0026-0030] so as to improve the quality of deposited films [0029], as taught by Ahn.
Regarding claim 10, Lu teaches the method [see title, 0055] of claim 9. Lu in view of Ahn (with reference to Ahn) also teaches wherein a) and b) are sequentially performed a first number of times before or after c) and d) are sequentially performed a second number of times (at block 212 fig. 2, steps a)-b) could be repeated [0054] multiple times and at block 222 fig. 2, steps c)-d) could be repeated [0059] multiple times to increase layer thickness).
Regarding claim 11, Lu teaches the method [see title, 0055] of claim 1. Lu also teaches wherein depositing the second metal oxide film (30) fig. 3A [0056] includes:
a) sequentially first, exposing the substrate (10) fig. 3A [0056] to a hafnium precursor and a zirconium precursor [0055, 0045]
b) sequentially first, exposing the substrate (10) to an oxidizer (water) [0055, 0045].
However, Lu does not explicitly disclose simultaneously exposing the substrate (10) to a hafnium precursor and a zirconium precursor and, sequentially second, exposing the substrate to a purge gas; and
b) sequentially second, exposing the substrate (10) to the purge gas.
Ahn teaches a method [see title, 0048, fig. 2] comprising simultaneously exposing the substrate to a hafnium precursor and a zirconium precursor (mixed gas [0076]) and, sequentially second, exposing the substrate to a purge gas [0076]; and
b) sequentially second, exposing the substrate (10) to the purge gas (after oxidant/water) [0076].
Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the ALD method of Lu to include a purging process after exposing the substrate to each precursor and oxidant [0051-0061] in order to remove byproducts and excess reactants [0026-0030] so as to improve the quality of deposited films [0029], as taught by Ahn. Further, mixing the hafnium- and zirconium- precursors quickens the ALD process [0076].
Response to Arguments
Applicant's arguments filed 11/21/2025 have been fully considered but they are rendered largely moot with respect to secondary reference Frank because primary reference Lu provides ample evidence that the second metal oxide film 30 may have a different chemical composition than the first metal oxide film 25. Not only does primary reference Lu suggest that second metal oxide film 30 comprises hafnium oxide whereas first metal oxide film 25 does not [0056, 0044-0045], Lu suggests that 30 may comprise elemental dopants [0044] such as Al [0065] in non-negligible quantities which affect relative amounts of Hf and Zr to O2 in the material, such that the chemical formula of layer 30 may be expressed as (AlZrHf)O2, with Al in 5-7 mol% [0065] - whereas 25 may not comprise a significant amount of aluminum [see fig. 6, 0065]. Moreover, Fig. 6 of Lu establishes that layer 30 may have a variable concentration of both hafnium and zirconium across in the vertical depth direction, such that different portions of layer 30 have different concentrations of Hf:Zr. This alone would be sufficient to address the limitation(s) “wherein the second metal oxide film (30) has a different hafnium oxide and zirconium oxide content than the first metal oxide film (25)” – because a portion of layer 30 would have a different Hf, Zr-oxide content relative to a different portion of layer 30, and layer 25 would necessarily have a different Hf, Zr-oxide content relative to at least one of these portions if it had a uniform (Hf, Zr) concentration profile. So, even if secondary reference Frank were to modify layer 25 of Lu to comprise both Hf and Zr, layer 30 would still comprise aluminum dopants and/or a graded concentration profile [see 0065, fig. 6 Lu]. Therefore, claim 1 and amended claim 21 are considered within the scope of the teachings of Lu in view of Frank - and thereby rejected under 35 U.S.C. 103.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Ahmed (U.S. PG Pub No US2015/0035085A1) (of record) teaches a related ALD process for the deposition of hafnium- and/or zirconium- oxide.
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/SEAN AYERS WINTERS/Examiner, Art Unit 2892 01/13/2026
/NORMAN D RICHARDS/Supervisory Patent Examiner, Art Unit 2892