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 .
Status of the Application
Claims 1-9, 11-18, and 27-33 remain pending in this application. Acknowledgement is made of the amendment received 06/16/2026. Claim 10 is canceled, claims 1, 2, 11, and 27 are amended. Claims 9 and 28 remain withdrawn.
It appears that the applicant’s response contains an inconsistency: claim 11 is identified as both elected (Group B, reply filed on 10/22/2025, remarks dated 06/16/2026 states only claims 9 and 28 are withdrawn) and withdrawn (claim amendment dated 06/16/2026). For the purpose of compact prosecution, the Examiner will treat claim 11 as being withdrawn in error.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-4, 7, 8, 11-18, 27, and 29-33 are rejected under 35 U.S.C. 103 as being unpatentable over Akselrod et al (US 20190301025 A1, as cited in IDS dated 07/12/2023, hereafter Akselrod).
Regarding claim 1, Akselrod, in at least one embodiment, teaches: A method for fabricating an optical metasurface (Akselrod 100, ¶0004, 0007, 0039-0044, figs 1B, 6A-I), comprising: forming a reflective backplane structure (Akselrod 104, ¶0056-0058, “reflects optical waves”, fig 2, 3) to by
etching a first dielectric layer (Akselrod 610, fig 6B, ¶0084, 0085, 708, 710, fig 7A, ¶0106) of a dielectric substrate (Akselrod 604, 606, 610, fig 6A, ¶0084, 702, fig 7A) to form a first plurality of trenches (Akselrod 609, ¶0085)(Akselrod fig 6B, ¶0085);
depositing a lower barrier layer (Akselrod 612, fig 6C, ¶0086, 706, fig 7A, ¶0106, “barrier material”, claim 1, “a conducting or dielectric barrier layer”) within the first plurality of trenches on sidewalls and a bottom wall of each of the first plurality of trenches (Akselrod fig 6C, ¶0082);
depositing a lower copper layer (Akselrod 614, fig 6C, ¶0086-0088, 704, fig 7A, ¶0106) on the lower barrier layer and within the first plurality of trenches to at least partially fill each of the first plurality of trenches (Akselrod fig 6C, ¶0084-0086);
planarizing the lower copper layer to expose an upper surface of the first dielectric layer (Akselrod 616, fig 6D)(Akselrod fig 6D, ¶0088), wherein the lower barrier layer (Akselrod 612) remains between the lower copper layer (Akselrod 614) and the dielectric substrate (Akselrod 604, 606, 610, 702) along sidewalls and a bottom wall of the lower copper layer (Akselrod fig 6D);
forming an optically transparent dielectric spacer layer (Akselrod 618, 712, 714, 716, ¶0089-0091, fig 6E, “SiN, SiCN, SiC, Al2O3, HfO2, SiO2 … optically transparent“) over the reflective backplane structure (Akselrod fig 6E, 7A);
forming an upper copper layer (Akselrod 718, fig 7A, ¶0106) with a conductive upper barrier layer (Akselrod 720, fig 7A, ¶0106) over the dielectric spacer layer (Akselrod fig 7A, ¶0106) by a damascene process (Akselrod ¶0077, 0106, “damascene process”), wherein the upper copper layer comprises a plurality of nano-gaps (Akselrod, ¶0106, region filled by 722, fig 7A, under a broadest reasonable interpretation (BRI) of “nano-gaps”, similar to 728, ¶0108) vertically extending from the dielectric spacer layer (Akselrod 618, 712, 714, 716)(Akselrod fig 7A, ¶0106), wherein the plurality of nano-gaps is filled with a dielectric fill material (Akselrod 722, fig 7A, ¶0106, “fills the space in the nano-gaps”), wherein the conductive upper barrier layer (Akselrod 720) is between the upper copper layer (Akselrod 718) and the dielectric spacer layer (Akselrod 618, 712, 714, 716)(Akselrod fig 7A, 720 is between 718 and 716), and also between the upper copper layer and the dielectric fill material (Akselrod 722)(Akselrod fig 7A, 720 is between 718 and 722);
removing the dielectric fill material (Akselrod 722) and a portion of the conductive upper barrier layer (Akselrod 720) from side portions of the upper copper layer in the nano-gaps (Akselrod fig 7B, ¶0107, 724 is formed by removing 722 and portions of 720 on the sidewalls of 718) to expose the side portions in the nano-gaps (Akselrod fig 7B, region filled by 722 becoming 724) of the upper copper layer (Akselrod fig 7B, side portions of 718 are exposed to 724), while retaining another portion of the conductive upper barrier layer between a base wall of the upper copper layer and the dielectric spacer layer (Akselrod fig 7B, portion of 720 are retained below 718 and between 718 and 716);
depositing a dielectric coating layer (Akselrod 726, fig 7C, ¶0108) over a top portion and exposed side portions of the upper copper layer to form a protected upper copper layer (Akselrod fig 7C, ¶0108); and
filling the nano-gaps (Akselrod fig 7B, 724 becoming 728) with an electrically tunable dielectric material (Akselrod 730, ¶0109)(Akselrod fig 7D, ¶0109) that has an electrically tunable refractive index (Akselrod ¶0048, “electrically-tunable material has a refractive index that can be tuned by applying an electric voltage”),
wherein after removing the dielectric fill material (Akselrod 722) and the portion of the conductive upper barrier layer (Akselrod 720, removed portions fig 7B)(Akselrod fig 7B), the lower barrier layer (Akselrod 612, 706) remains between the lower copper layer (Akselrod 614, 704) and the dielectric substrate (Akselrod 604, 606, 610, 702) along the sidewalls and the bottom wall of the lower copper layer (Akselrod fig 7B-D, 9, ¶0107-0109).
Akselrod does not explicitly teach: a lower dielectric barrier layer.
Akselrod further teaches: a dielectric barrier layer (Akselrod 620) between a copper layer (Akselrod 622) and a dielectric substrate (Akselrod 602, 610, 618)(Akselrod fig 6F).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the lower barrier layer of Akselrod to include a dielectric material, in order to reduce absorption of optical light by the lower barrier layer, thereby improving metasurface efficiency (Akselrod ¶0105, “barrier material”, claim 1, “a conducting or dielectric barrier layer”).
Further, the substitution of a dielectric barrier for liner 612 represents a simple substitution of one known element for another to obtain predicable results. MPEP 2143(I)(B). Akselrod claims 1 and 21 recite “conducting or dielectric barrier layer” as alternatives in optical metasurface fabrication, establishing that both were known in the art to perform the same function of preventing copper diffusion. A person of ordinary skill in the art would have found it obvious to select the dielectric barrier option because Akselrod recognizes that Ta/TaN barriers are “very absorptive to optical light” and cause “very low or nearly zero efficiency” (Akselrod ¶0105), whereas dielectric barrier maintain optical transparency (Akselrod ¶0091).
Regarding claim 2, Akselrod teaches: The method of claim 1, wherein the lower dielectric barrier layer (Akselrod 612 as modified by 620) operates to prevent copper diffusion into the dielectric substrate (Akselrod 604, 606, 610, 702)(Akselrod ¶0081, “barrier layer can reduce copper diffusivity … isolates the copper from the dielectric insulator”, ¶0091, “barriers to copper diffusion”).
Regarding claim 3, Akselrod teaches: The method of claim 1, wherein the lower dielectric barrier layer (Akselrod 612 as modified by 620) comprises one or more of SiN, SiC, SiCN, AL2O3, HfO2, and SiO2 (Akselrod ¶0091, “SiN … SiCN … SiC … AL2O3, HfO2 … SiO2”).
Regarding claim 4, Akselrod teaches: The method of claim 1, wherein the dielectric coating layer (Akselrod 726) comprises one or more of SiN, SiC, SiCN, AL2O3, HfO2, and SiO2 (Akselrod ¶0101, “SiN, SiCN, SiC, AL2O3, HfO2, SiO2, claim 2).
Regarding claim 7, Akselrod teaches: The method of claim 1, wherein the dielectric spacer layer (Akselrod 618, 712, 714, 716) comprises a plurality of optically transparent dielectric layers (Akselrod ¶0090-0091, “a plurality of dielectric layers … dielectric material, such as SiN, SiCN, SiC, AL2O3, HfO2, SiO2”, ¶0091, “optically transparent … dielectric material, such as SiN, SiCN, SiC, AL2O3, HfO2, SiO2”, ¶0106, 0105).
Regarding claim 8, Akselrod teaches: The method of claim 1, wherein the dielectric spacer layer (Akselrod 618, 712, 714, 716) comprises a low-k dielectric layer (Akselrod claim 14, “dielectric spacer comprises at least … at least a thick low-k dielectric layer”).
Regarding claim 11, Akselrod teaches: The method of claim 10, wherein the conductive upper barrier layer (Akselrod 720) comprises one or more of tantalum (Ta), tantalum nitride (TaN), and titanium nitride (TiN)(Akselrod ¶0106, “Ta and/or TaN”).
Regarding claim 12, Akselrod teaches: The method of claim 1, wherein the tunable dielectric material (Akselrod 730) comprises one or more of liquid crystal, an electro-optic polymer, a chalcogenide glass, and a semiconductor material (Akselrod ¶0048, “liquid crystals, Electro-optic (EO) polymer material, or Chalcogenide Glasses”).
Regarding claim 13, Akselrod teaches: The method of claim 1, further comprising: encapsulating the tunable dielectric material (Akselrod 730) with one or more of glass, a polymer, and sapphire (Akselrod 732, ¶0104, 0109, fig 7D, “encapsulating the electrically-tunable material with an optically transparent material, such as glasses and polymers”).
Regarding claim 14, Akselrod teaches: The method of claim 1, wherein the upper copper layer (Akselrod 718) comprises a plurality of copper pillars vertically extending from the dielectric spacer layer (Akselrod 618, 712, 714, 716)(Akselrod 718, ¶0106, fig 7A).
Regarding claim 15, Akselrod teaches: The method of claim 14, wherein the plurality of copper pillars (pillars comprising Akselrod 718) comprises a two-dimensional array of copper pillars (Akselrod ¶0040, “two-dimensional (2D) array … includes a pair of metal pillars”).
Regarding claim 16, Akselrod teaches: The method of claim 14, wherein the plurality of copper pillars (pillars comprising Akselrod 718) comprises a one-dimensional array of elongated copper rails. (Akselrod ¶0040, “one-dimensional (1D) array”, 0052, “columns of metallic holographic elements 106 arranged linearly on a wafer”, fig 1B).
Regarding claim 17, Akselrod, in at least one embodiment, teaches: The method of claim 14, wherein the lower copper layer (Akselrod 614, 704) comprises copper patches (Akselrod 704, ¶0106) positioned under the nano-gaps (Akselrod 728, ¶0108) between adjacent copper pillars (pillars comprising Akselrod 718, ¶0108) of the upper copper layer (Akselrod 718)(Akselrod fig 7A-D).
Regarding claim 18, Akselrod teaches: The method of claim 17, wherein the copper patches (Akselrod 704) have a width corresponding to a pitch of the adjacent copper pillars (pillars comprising Akselrod 718) of the upper copper layer (Akselrod 718)(Akselrod claim 17, fig 7D).
Regarding claim 27, Akselrod, in at least one embodiment, teaches: A method for fabricating an optical metasurface (Akselrod 100, ¶0004, 0007, 0039-0044, 0083-0109, figs 1B, 6A-I, 7A-D), comprising:
forming an optically reflective metallic layer (Akselrod 104, 614, 704, ¶0056-0058, “reflects optical waves”, fig 2, 3, at least comprises a metal, copper) by:
etching a first dielectric layer (Akselrod 610, fig 6B, ¶0084, 0085, 708, 710, fig 7A, ¶0106) to form a first plurality of trenches (Akselrod 609, ¶0085) in the dielectric layer (Akselrod fig 6B, ¶0085),
depositing a barrier layer (Akselrod 612, fig 6C, ¶0086, 706, fig 7A, ¶0106, “barrier material”, claim 1, “a conducting or dielectric barrier layer”) within the first plurality of trenches on sidewalls and a bottom wall of each of the first plurality of trenches (Akselrod fig 6C, ¶0082), wherein the barrier layer operates to prevent metallic diffusion or corrosion (Akselrod ¶0046, 0081, “prevents copper from diffusion”, claim 21);
depositing a reflective metal (Akselrod 614, fig 6C, ¶0086-0088, 704, fig 7A, ¶0106) on top of the barrier layer within the first plurality of trenches to fill each of the first plurality of trenches (Akselrod fig 6C, ¶0084-0087);
planarizing the reflective metal to expose an upper surface of the first dielectric layer (Akselrod 616, fig 6D)(Akselrod fig 6D, ¶0088), wherein the barrier layer (Akselrod 612) remains between the reflective metal (Akselrod 614) and the first dielectric layer (Akselrod 610) along sidewalls and a bottom wall of the reflective metal within each of the first plurality of trenches (Akselrod fig 6D);
depositing an optically transparent dielectric spacer layer (Akselrod 618, 712, 714, 716, ¶0089-0091, fig 6E, “SiN, SiCN, SiC, Al2O3, HfO2, SiO2 … optically transparent“) over the optically reflective metallic layer (Akselrod fig 6E, 7A);
depositing a dielectric etch layer (Akselrod 624, 722, ¶0098) over the dielectric spacer layer (Akselrod ¶0091, 0098, fig 6F, 7A); and
forming an array of metallic holographic elements (Akselrod 624, 718, 106/102 ¶0039-0044) by:
etching the dielectric etch layer (Akselrod 624, 722) to form a second plurality of trenches (Akselrod fig 6F, ¶0098, space occupied by 622/718 in fig 6F/7A) in the dielectric etch layer (Akselrod ¶0091, 0094, fig 6F, 7A),
depositing a conductive barrier layer (Akselrod 720, ¶0106, “conducting barrier layer 720”) within the second plurality of trenches (Akselrod ¶0091, 0098, 0106, fig 6F, 7A) on sidewalls and a base wall of each of the second plurality of trenches (Akselrod fig 7A),
wherein the conductive barrier layer (Akselrod 720) operates to prevent metallic diffusion or corrosion (Akselrod ¶0046, 0081, 0106, “prevents copper from diffusion”, claim 21),
depositing a conductive metal (Akselrod 718, fig 7A, ¶0106) on top of the conductive barrier layer (Akselrod ¶0091, 0098, fig 7A) within the second plurality of trenches to fill each of the second plurality of trenches (Akselrod fig 6F, 7A),
removing the dielectric etch layer (Akselrod 624, 722) and the conductive barrier layer from sidewalls of the conductive metal (Akselrod fig 7B) between adjacent trenches in the second plurality of trenches to form a plurality of nano-gaps (Akselrod 724)(Akselrod fig 7B, ¶0098-0099, 0107, 724 is formed by removing 722 and portions of 720 on the sidewalls of 718) between exposed metal pillars (pillars comprising Akselrod 718)(Akselrod fig 7B), while retaining a remaining portion of the conductive barrier layer (Akselrod 720) between a base wall of each exposed metal pillar (Akselrod 718) and the dielectric spacer layer (Akselrod 618, 712, 714, 716)(Akselrod fig 7B, portion of 720 are retained below 718 and between 718 and 716),
depositing a dielectric coating layer (Akselrod 625, ¶0100-0101, 726, fig 7C, ¶0108) over a top portion and exposed side portions of the exposed metal pillars to form protected metal pillars (Akselrod fig 6H, Akselrod fig 7C, ¶0108), and
filling the nano-gaps (Akselrod fig 7B, 724 becoming 728) with an electrically tunable dielectric material (Akselrod 626, ¶0102-0103, 730, ¶0109)(Akselrod fig 6I, 7D, ¶0109) that has an electrically tunable refractive index (Akselrod ¶0048, “electrically-tunable material has a refractive index that can be tuned by applying an electric voltage”),
wherein, after removing the dielectric etch layer (Akselrod 624, 722) and the conductive barrier layer (Akselrod 720) from the sidewalls of the conductive metal (Akselrod 718)(Akselrod 720 removed portions fig 7B)(Akselrod fig 7B), the barrier layer (Akselrod 612, 706) remains between the reflective metal (Akselrod 614, 704) and the first dielectric layer (Akselrod 610, 708, 710) along the sidewalls and the bottom wall of the reflective metal within each of the first plurality of trenches (Akselrod fig 7B-D, 9, ¶0107-0109).
Akselrod does not explicitly teach: a dielectric barrier layer.
Akselrod further teaches: a dielectric barrier layer (Akselrod 620) between a copper layer (Akselrod 622) and a dielectric substrate (Akselrod 602, 610, 618)(Akselrod fig 6F).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the barrier layer of Akselrod to include a dielectric material, in order to reduce absorption of optical light by the barrier layer, thereby improving metasurface efficiency (Akselrod ¶0105, “barrier material”, claim 1, “a conducting or dielectric barrier layer”).
Further, the substitution of a dielectric barrier for liner 612 represents a simple substitution of one known element for another to obtain predicable results. MPEP 2143(I)(B). Akselrod claims 1 and 21 recite “conducting or dielectric barrier layer” as alternatives in optical metasurface fabrication, establishing that both were known in the art to perform the same function of preventing copper diffusion. A person of ordinary skill in the art would have found it obvious to select the dielectric barrier option because Akselrod recognizes that Ta/TaN barriers are “very absorptive to optical light” and cause “very low or nearly zero efficiency” (Akselrod ¶0105), whereas dielectric barrier maintain optical transparency (Akselrod ¶0091).
Regarding claim 29, Akselrod teaches: The method of claim 27, wherein the dielectric barrier layer (Akselrod 612, 706 as modified by Akselrod 620) is optically reflective (Akselrod ¶0091, “SiN … SiCN … SiC … AL2O3, HfO2 … SiO2”, similarly the Applicant discloses suitable materials for a dielectric barrier layer includes “SiN, SiC, SiCN, AL2O3, HfO2, and SiO2”, spec ¶0065-0066, therefore must have the same properties, including being “optically reflective.” see MPEP 2112.01).
Regarding claim 30, Akselrod teaches: The method of claim 27, wherein the reflective metal (Akselrod 614, 704) comprises copper (Akselrod ¶0088).
Regarding claim 31, Akselrod teaches: The method of claim 27, wherein the conductive metal (Akselrod 718) comprises copper (Akselrod ¶0091, 0106).
Regarding claim 32, Akselrod teaches: The method of claim 27, wherein the conductive metal (Akselrod 718) comprises copper (Akselrod ¶0091, 0106) and wherein depositing the copper comprises:
depositing a copper seed layer on at least a base wall and sidewalls of each of the second plurality of trenches (Akselrod ¶0087), and
depositing copper to fill any remaining volume in each of the second plurality of trenches using an electrochemical plating (ECP) process (Akselrod ¶0087).
Regarding claim 33, Akselrod teaches: The method of claim 27, wherein the conductive barrier layer (Akselrod 720) comprises one of tantalum (Ta), tantalum nitride (TaN), and titanium nitride (TiN)(Akselrod ¶0106, “Ta and/or TaN”).
Claims 5 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Akselrod et al (US 20190301025 A1, as cited in IDS dated 07/12/2023, hereafter Akselrod) as applied to claim 1 above, and further in view of Shahrestani et al (US 20250216590 A1, here after Shahrestani).
Regarding claim 5, Akselrod teaches: The method of claim 1.
Akselrod does not teach: prior to filling the nano-gaps with the electrically tunable dielectric material, depositing an optically reflective metal coating layer over the dielectric coating layer.
Shahrestani, in the same field of endeavor of semiconductor device manufacturing, teaches: depositing an optically reflective metal coating layer (Shahrestani 113, ¶0101, 0065, “silver”, similarly the Applicant discloses suitable materials for an optically reflective metal coating layer includes “silver”, spec ¶0036, therefore must have the same properties, including being “optically reflective.” see MPEP 2112.01) over a dielectric nanostructure (Shahrestani 112, ¶0087)(Shahrestani ¶0087).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the method of Akselrod to include “depositing an optically reflective metal coating layer over the dielectric coating layer”, prior to filling the nano-gaps, as taught by Shahrestani, in order to enable plasmonic resonances for additional spectral control and/or turning capabilities for the optical metasurface (Shahrestani ¶0105), and/or in order to improve a reflectivity of a pillar surface while maintaining electrical isolation between adjacent pillars (Akselrod ¶0057, 0092).
Regarding claim 6, Akselrod in view of Shahrestani teaches: The method of claim 5, wherein the optically reflective metal coating layer (Akselrod as modified to include Shahrestani 113) comprises silver (Shahrestani ¶0065, 0101, “silver”).
Response to Arguments
Applicant’s arguments filed 06/16/2026, with respect to claim 2 has been fully considered and is persuasive. The 35 USC § 112 rejection of claim 2 has been withdrawn.
Applicants’ arguments filed 06/16/2026 have been fully considered but they are not persuasive.
Regarding claims 1 and 27, the applicant alleges at pages 10-11:
Akselrod describes an upper-pillar process in which a dielectric barrier layer 620 covers the sidewalls and bottom of copper pillars 622. See Akselrod [0091], FIG. 6F. Akselrod expressly explains that, if a dielectric liner is used for the upper dielectric barrier layer 620, electrical via connections between the copper pillars 622 and copper patches 614 are not possible, and electrical contact must instead be made from another layer. See Akselrod [0092]. That embodiment, therefore, does not teach the amended claims, which require upper metallic elements with a conductive barrier retained at the base wall after sidewall removal.
Examiner’s Response: The examiner respectfully disagrees. In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., electrical via connection between copper pillar and copper patches) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Further, the conductive upper barrier layer recited in claims 1 and 27 are not mapped to the dialectic barrier layer 620 of fig 6F; instead, it is mapped to the conducting barrier layer 720. The embodiment of fig 6F is relied upon for its teaching that a dialectic barrier layer is deposited to cover the sidewalls and the bottom of a trench.
Regarding claims 1 and 27, the applicant further alleges at page 11:
Akselrod also describes a different upper-pillar embodiment in which copper pillars 718 are initially formed with a conducting barrier layer 720, and the conducting barrier layer is then removed from the sidewalls of the copper pillars while the bottom conducting barrier layer remains. See Akselrod [0105]-[0107], FIGS. 7A-7D. But in that embodiment, the lower copper patches 704 are protected by a conducting barrier 706, such as Ta and/or TaN. See Akselrod [0106]. Thus, Akselrod's conductive-upper-barrier embodiment does not teach the amended lower-layer method steps with a lower dielectric barrier layer deposited on, and retained along, the sidewalls and bottom wall of the lower reflective metal.
Respectfully, the amended claims are not directed merely to substituting a material label. They recite a particular method sequence applied differently to two different metal layers: (1) the lower reflective metal is fabricated with a retained dielectric barrier along the sidewalls and bottom wall, while (2) the upper metal is fabricated with a conductive barrier that is later selectively removed from upper sidewall/nano-gap regions but retained at the base wall. Akselrod does not disclose this combination of steps in a single method, and its examples point in different directions.
Examiner’s Response: The examiner respectfully disagrees. In response to applicant's argument that Akselrod does not disclose the claimed combination of steps in a single method, the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). In this case, while no single embodiment depicts a dielectric barrier at the lower trench, Akselrod claims 1 and 21 recite the composition of such a layer includes “a conducting or dielectric barrier layer” for the same barrier step, and Akselrod state that the method “The method replaces a conducting barrier layer (e.g. Ta and/or Ta nitride) commonly used in a conventional damascene process with a dielectric barrier layer” (Akselrod ¶0083), clearly identifying the conductive liner 612 as the barrier replaceable as a dielectric. Therefore, Akselrod suggests the claimed lower dielectric layer as claimed.
Regarding claims 1 and 27, the applicant further alleges at page 11:
The proposed modification also would not have produced predictable results. Akselrod focuses on optical loss caused by Ta/TaN in the upper metallic holographic elements that interact with the optical field. By contrast, the present claims concern the sidewalls and bottom wall of the lower reflective metal, which are not the same optical environment as the exposed sidewalls of the upper holographic elements. The present application expressly identifies this distinction, explaining that it was not intuitive that Ta or TaN on the sidewalls and bottom wall of the lower metal layer would significantly impact reflectivity, and that, contrary to expectations, using a dielectric barrier layer with low optical absorptive properties on the sidewalls and bottom wall of the metal patch increases the reflectivity of the lower metal layer. See Spec. [0067].
Examiner’s Response: The examiner respectfully disagrees; the result is not unexpected and is predicted by Akselrod itself. Akselrod disclosed that Ta and TaN barrier materials “are very absorptive to optical light at the frequency ranges of the holographic metasurfaces” and their presence yields “very low or nearly zero efficiency” (Akselrod ¶0105), that dielectric barriers materials are optically transparent while remaining barriers to copper diffusion (Akselrod ¶0091), and that copper patches form the reflective backplane that reflects the optical waves (Akselrod ¶0056-0058). Therefore, replacement of a Ta/TaN barrier layer with a dielectric barrier layer would expectedly improve the reflectivity, and thus the efficiency of a metasurface. Akselrod states both the problem and its solution at the level of a metasurface and a damascene process as a whole, rather than as being confined to the upper holographic elements (Akselrod ¶0083, “the method replaces a conducting barrier layer (e.g. Ta and/or Ta nitride) commonly used in a conventional damascene process with a dielectric barrier layer for the copper holographic metasurfaces”). One ordinary skill in the art would have expected beneficial results at any copper level formed by the damascene process, including a lower backplane.
Further, claims 1 and 27 do not recite a reflectivity or optical property of the lower dielectric barrier layer, and the assertion is supported only by a statement of an increase in reflectivity within the specification without comparative data (see MPEP 716.02(b), 716.02(d)). Unexpected results must be established by factual evidence of which none appears to have been shown, nor a greater than expected result, a superiority of a shared property, presence of an unexpected property, nor absence of an expected property.
Regarding claims 1 and 27, the applicant further alleges at page 12:
Accordingly, Akselrod neither teaches nor provides a reasoned motivation to arrive at the amended claims without impermissible hindsight. In particular, Akselrod does not teach or suggest forming the lower reflective layer with a retained dielectric barrier on sidewalls and a bottom wall while separately forming the upper holographic elements with a conductive barrier that is selectively removed from sidewalls and retained at the base wall. Applicant respectfully submits that independent claims 1 and 27, as amended, are patentable over Akselrod.
Examiner’s Response: The examiner respectfully disagrees. In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
Further, in response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, the motivation as stated above is to increase the metasurface efficiency by reducing absorption of optical light by a barrier layer, and the materials, reasons, and motivation to interchange the materials are each taught by Akselrod (Akselrod ¶0083, 0091, 0095, 0105, claims 1 and 21).
Conclusion
Applicants’ amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicants are 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NICHOLAS B. MICHAUD whose telephone number is (703)756-1796. The examiner can normally be reached Monday-Friday, 0800-1700 Eastern Time.
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/NICHOLAS B. MICHAUD/
EXAMINER
Art Unit 2818
/BRIAN TURNER/Primary Examiner, Art Unit 2818
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