Simultaneous volumetric 3D printing of multi-material conductive and insulating nanostructures using holographic metasurface nanolithography

Abstract

An exemplary holographic metasurface lithography system and method that project a hologram having two or more different wavelengths of light onto a hybrid resin to simultaneously or concurrently cure / form both (i) a first material structure, e.g., a metal structure and (ii) a second material structure, e.g., a polymer structure, from the hybrid resin in the same three-dimensional space. The hologram is generated by a metasurface mask that encodes spatial information for both the metal structure and the polymer structure, and the resin has both (i) UV-sensitive metal precursors to form the metal structure and (ii) monomers, crosslinkers, wavelength-selective photosystems to form the polymer structure.

Description

SIMULTANEOUS VOLUMETRIC 3D PRINTING OF MULTI¬MATERIAL CONDUCTIVE AND INSULATING NANOSTRUCTURESUSING HOLOGRAPHIC METASURFACE NANOLITHOGRAPHYRELATED APPLICATIONThis U.S. application claims priority to, and the benefit of, U.S. Provisional Patent Application No. 63 / 658,163, filed June 10, 2024, entitled “SIMULTANEOUS VOLUMETRIC 3D PRINTING OF MULTI-MATERIAL CONDUCTIVE AND INSULATING NANOSTRUCTURES USING HOLOGRAPHIC METASURFACE NANOLITHOGRAPHY,” which is incorporated by reference herein in its entirety.BACKGROUND

[0001] 3D-printing and lithography systems can form a polymeric or metallic three- dimensional object in a layer-by-layer process. With 3D printing, a nozzle extrudes molten plastic, metal, or powder material that is cured to form a layer; the process is then repeated to form another layer to form a three-dimensional structure. Complex structures and overhangs are additionally formed using supporting structures that are built in proximity to the desired structure.

[0002] Semiconductor and device fabrication entails (i) growing layers of material on a wafer and using lithography on a photoresist that is patterned and selectively removed on a top layer that can be etched or deposited with material to form a desired structure. Metal layers are typically deposited in the formed layers.SUMMARY

[0003] An exemplary holographic metasurface lithography system and method are disclosed that can project a hologram having two or more different wavelengths of light (one UV and one non-UV, e.g.. visible light) onto a hybrid resin to simultaneously or concurrently cure / form both (i) a first material structure, e.g., a metal structure and (ii) a second material structure, e.g., a polymer structure, from the hybrid resin in the same three-dimensional space. The first material structure can be a metal structure, e.g., a conductor, and the second material structure can be a polymer structure, e.g., a dielectric. The hologram is generated by a metasurface mask that encodes spatial information for both the metal structure and the polymer structure, and the resin has both (i) UV-sensitive metal precursors to form the metal structure and (ii) monomers, crosslinkers, wavelength-selective photosystems to form the polymerstructure. In other embodiments, the first material structure can be a first polymer structure, and the second material structure can be a second polymer structure.

[0004] Notably, the formation of both metal structures (as conductors) and polymer structures (as insulators) simultaneously or concurrent to one another and in the same three- dimensional space can facilitate the generation of new classes of semiconductor devices and electrical components, including for packaging and interconnect devices or components. The rate of simultaneous or concurrent formation of the polymer structures and metal structures can be varied to allow one of the materials (e.g., polymer) to form as support for the other (e.g., polymer structure forming first to support a metal structure). To this end, highly complex geometric structures, including completely freeform curved or non-continuous structures, can be formed of the metal structure that would be difficult to do using conventional conventional semiconductor and device fabrication and 3D printing technology, including overhang structures.

[0005] The exemplary7system and method can use sub-wavelength-pattemed metasurface masks (metamasks) to create a hologram (e.g., multi-colored holograms) in a photocurable metal-polymer hybrid resin. In some embodiments, the holographic metasurface lithography system includes optical and laser systems and metasurface masks to generate multiple holographic beams, each having the UV and non-UV light components, including a first holographic beam and a second holographic beam that can be simultaneously projected onto the resin to intersect one another, or in a sequence to effectively do the same, to improve the curing / forming speed and / or provide finer spatial resolution for the 3D structure formation.

[0006] The process allows entire 3D, multi-material (insulators and conductors) structures (microstructures, nanostructures, and large-scale structures) to be patterned using a single light exposure (though multiple exposures can be applied). Metasurfaces can be encoded with higher information density than traditional spatial light modulators such as digital micromirror devices, so the use of metasurface optics in the exemplary system and method (i) can overcome many of the low-resolution and small-patteming-area challenges presented by conventional holographic 3D printing approaches and (ii) can overcome challenges associated with printing heterogeneous structure having multiple materials via conventional semiconductor and device fabrication and 3D printing technology7.

[0007] Multiple holographic beams, e.g., 2, 3, 4, etc., can be projected into the resin at a single location to improve the curing / processing time for the metal and polymer structure or to improve the resolution of the structures. In some embodiments, the intersection of theholographic beams can provide a secondary design space for the smaller-scale structures or features.

[0008] The exemplary system and method are highly scalable, with the size of the hologram produced being limited only by the size of the fabricated metasurface, which can be produced at a full wafer scale if desired. The exemplary' system and method can be employed to fabricate nano-scale structures as well as large-scale structures (e.g., microscale). It can be used for highly precise semiconductor processing (e.g., microprocessors, microprocessor cores. GPU cores, ASICs, Al chips) as well as large-scale, high-volume semiconductor processing production (e.g., photovoltaics). The exemplary system and method can also be employed to fabricate interconnects, e.g., for chiplet or multi-die or die-component integration, as well as packaging. Routing traces and layers can be fabricated in traditional planar (e.g., metal layers) and vertical structures (e.g., via) or in optimized highly curved structures in all three axes. To this end, vias can be formed as 3D or 2D helical structures and 3D or 2D zig-zag structures; the same structures can be formed for routing traces in 3D or 2D.

[0009] In some aspects, the techniques described herein relate to a method including: combining, via a first optics assembly, (i) a first ultraviolet (UV) beam from a first UV source and (ii) a first non-UV beam (having at least one visible light beam) from a first laser, to form a first combined multi-spectral beam having both UV and non-UV spectral components; combining, via a second optics assembly, (i) a second ultraviolet (UV) beam from a second UV source and (ii) a second non-UV beam (having at least one visible light beam) from a second laser, to form a second combined multi-spectral beam having both UV and non-UV spectral components; directing the first combined multi-spectral beam through a first metamask having a first patterned metasurface formed thereon to generate a first multi-spectral hologram beam, wherein the first patterned metasurface has a first pattern for a first workpiece structure in a first material and a second workpiece structure in a second material, wherein the first pattern forms a first hologram; directing the second combined multi-spectral beam through a second metamask having a second patterned metasurface formed thereon to generate a second multi-spectral hologram beam, wherein the second patterned metasurface has a second pattern for the first workpiece structure in the first material and the second workpiece structure in the second material, wherein the second pattern forms a second hologram; and projecting the first multi-spectral hologram beam and the second multi-spectral hologram beam on a metal- polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose the first hologram and the second hologram in a 3D volume in the metal-polymer hybrid resin, wherein the metal-polymer hybrid resin includes (i) the first material having a metal component and (ii)the second material having a polymer component, wherein the first material in the exposed 3D volume having been exposed by both the first multi-spectral hologram beam and the second multi-spectral hologram beam (e.g., at the intersection or overlapping portion thereof) is heated to form a metallic structure within the 3D volume, and wherein the second material in the exposed 3D volume having been exposed by both the first multi-spectral hologram beam and the second multi-spectral hologram beam (e.g., at the intersection or overlapping portion thereof) is cured to form a polymer structure within the 3D volume.

[0010] In some aspects, the techniques described herein relate to a method, wherein the first non-UV beam (having at least one visible light beam) from the first laser is a first visible light, wherein the second non-UV beam (having at least one visible light beam) from the second laser is a second visible light, wherein the first visible light is the same as the second visible fight.

[0011] In some aspects, the techniques described herein relate to a method, wherein the first non-UV beam (having at least one visible light beam) from the first laser is a first visible light, wherein the second non-UV beam (having at least one visible light beam) from the second laser is a second visible light, wherein the first visible light is different from the second visible fight.

[0012] In some aspects, the techniques described herein relate to a method, wherein the first hologram and the second hologram are simultaneously projected in the 3D volume in the metal-polymer hybrid resin.

[0013] In some aspects, the techniques described herein relate to a method, wherein the first hologram and the second hologram are contemporaneously projected (e.g., subsequent to each other) in the 3D volume in the metal-polymer hybrid resin.

[0014] In some aspects, the techniques described herein relate to a method, wherein the first material and the second material provide insulating and conducting structures in the 3D volume.

[0015] In some aspects, the techniques described herein relate to a method further including: projecting the first multi-spectral hologram beam and the second multi-spectral hologram beam at a second location of the metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose a third hologram and a fourth hologram in a second 3D volume in the metal-polymer hybrid resin.

[0016] In some aspects, the techniques described herein relate to a method, wherein the second material is cured to form the polymer structure within the 3D volume at a first rate, and wherein the first material is heated at a second rate to form the metallic structure within thecured polymer structure within the 3D volume, wherein the first rate is faster than the second rate.

[0017] In some aspects, the techniques described herein relate to a method, wherein the metallic structure includes an interconnect structure (e.g., redistribution layer, e.g., standard redistribution layer or freeform redistribution layer, e.g., for multiple stacked IC chips, chiplets, active or passive components, etc., or for multiple IC chips, chiplets, active or passive components, combined in multiple orientations).

[0018] In some aspects, the techniques described herein relate to a method, wherein the metallic structure includes an interconnect structure, a routing structure (layout, vias), a portion of a ground plane, a portion of a passive electric component (capacitor, inductor), functionalized electric component (e.g.. waveguide, antenna), thermal regulation component, or a combination of both.

[0019] In some aspects, the techniques described herein relate to a method, wherein the polymer structure is a dielectric that forms an interconnect supporting structure.

[0020] In some aspects, the techniques described herein relate to a method, wherein the polymer structure is a dielectric that supports the metallic structure.

[0021] In some aspects, the techniques described herein relate to a method, wherein the metal-polymer hybrid resin includes (i) a polymer, (ii) a metal compound (e.g., metal-organic decomposition (MOD) silver ink or precursor, e.g., upon UV absorption the silver ions heat up, leading to decomposition of the silver complexes and formation of metallic silver), (iii) a visible light photoinitiator (e.g., visible light radical photoinitiator), and (iv) a UV light photoinhibitor (e.g., UV light radical photoinhibitor) (e.g., to prevent polymerization in the UV exposure regions, to allow only the silver metal to form in this region).

[0022] In some aspects, the techniques described herein relate to a method, wherein the UV light photoinhibitor includes bis[2-(o-chlorophenyl)-4,5-diphenylimidazole] (o-Cl-HABI).

[0023] In some aspects, the techniques described herein relate to a method, wherein a region of intersection or overlapping portion of the first multi-spectral hologram beam and the second multi-spectral hologram beam provides exposure at sub-500nm resolution (e.g., less than 500 nm. less than 100 nm, less than 10 nm).

[0024] In some aspects, the techniques described herein relate to a method, wherein a region of intersection or overlapping portion of the first multi-spectral hologram beam and the second multi-spectral hologram beam provides exposure at micrometer resolution.

[0025] In some aspects, the techniques described herein relate to a method including: directing a first beam having a UV component through a first metamask having a first patternedmetasurface formed thereon to generate a first hologram beam, wherein the first patterned metasurface has a first pattern for a first workpiece structure in a first material, wherein the first pattern forms a first hologram having 3D pattern for the first workpiece structure; directing a second beam having a visible light component through a second metamask (e.g., same metamask at different regions or different metamasks) having a second patterned metasurface formed thereon to generate a second hologram beam, wherein the second patterned metasurface has a second pattern for a second workpiece structure in a second material, wherein the second pattern forms a second hologram having 3D pattern for the second workpiece structure, wherein the first workpiece structure and the second workpiece structure form an integrated component in a same 3D volume; projecting the first hologram beam and the second hologram beam on a metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose the first hologram and the second hologram in the same 3D volume in the metal- polymer hybrid resin, wherein the metal-polymer hybrid resin includes (i) the first material having a metal component and (ii) the second material having a polymer component, wherein the first material in the exposed 3D volume having been exposed by the first hologram beam is heated to form a metallic structure within the 3D volume, and wherein the second material in the exposed 3D volume having been exposed by the second multi-spectral hologram beam is cured to form a polymer structure within the 3D volume.

[0026] In some aspects, the techniques described herein relate to a method, wherein the first hologram and the second hologram are simultaneously projected in the 3D volume in the metal-polymer hybrid resin.

[0027] In some aspects, the techniques described herein relate to a method, wherein the first hologram and the second hologram are contemporaneously projected (e.g., subsequent to each other) in the 3D volume in the metal-polymer hybrid resin.

[0028] In some aspects, the techniques described herein relate to a method, wherein the first material and the second material provide insulating and conducting structures in the 3D volume.

[0029] In some aspects, the techniques described herein relate to a method further including: projecting the first hologram beam and the second hologram beam at a second location of the metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose a third hologram and a fourth hologram in a second 3D volume in the metal-polymer hybrid resin.

[0030] In some aspects, the techniques described herein relate to a method, wherein the second material is cured to form the polymer structure within the 3D volume at a first rate, andwherein the first material is heated at a second rate to form the metallic structure within the cured polymer structure within the 3D volume, wherein the first rate is faster than the second rate.

[0031] In some aspects, the techniques described herein relate to a method, wherein the metallic structure includes an interconnect structure (e.g., redistribution layer, e.g., standard redistribution layer or freeform redistribution layer, e.g., for multiple stacked IC chips, chiplets, active or passive components, etc., or for multiple IC chips, chiplets. active or passive components, combined in multiple orientations).

[0032] In some aspects, the techniques described herein relate to a method, wherein the metallic structure includes an interconnect structure, a routing structure (layout, vias), a portion of a ground plane, a portion of a passive electric component (capacitor, inductor), functionalized electric component (e.g., waveguide, antenna), thermal regulation component, or a combination of both.

[0033] In some aspects, the techniques described herein relate to a method, wherein the polymer structure is a dielectric that forms an interconnect supporting structure.

[0034] In some aspects, the techniques described herein relate to a method, wherein the polymer structure is a dielectric that supports the metallic structure.

[0035] In some aspects, the techniques described herein relate to a method, wherein the hybrid resin includes (i) a polymer, (ii) a silver ink (e.g., metal-organic decomposition (MOD) silver precursor, e.g.. upon UV absorption, the silver ions heat up. leading to decomposition of the silver complexes and formation of metallic silver), (iii) a visible light radical photoinitiator, and (iv) a UV light radical photoinhibitor (e.g., to prevent polymerization in the UV exposure regions, to allow only the silver metal to form in this region).

[0036] In some aspects, the techniques described herein relate to a method, wherein the UV light radical photoinhibitor includes bis[2-(o-chlorophenyl)-4,5-diphenylimidazole] (o-Cl- HABI).

[0037] In some aspects, the techniques described herein relate to a system configured to perform any one 1-28 Multi-channel multi-spectral exposure.

[0038] In some aspects, the techniques described herein relate to a system including: at least one UV laser, including a first UV laser and a second UV laser; at least one visible light laser, including a first visible light laser and a second visible light laser; a metasurface mask having at least one patterned metasurface formed thereon, including a first patterned metasurface, wherein the first paterned metasurface has a first patern for a first workpiece structure in a first material, wherein the first patern forms a first hologram; a first opticalassembly configured to: combine (i) a first UV beam from the first UV laser and (i) a first visible light beam from the first visible light laser, to form a first combined multi-spectral beam having both UV and visible light components, direct the first combined multi-spectral beam through a metasurface mask to generate a first multi-spectral hologram beam, wherein the first patterned metasurface has a first pattern to form, as a first hologram, both (i) a first workpiece structure in a first material and a second workpiece structure in a second material in a same 3D volume, and direct the first multi-spectral hologram beam on a metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose the first hologram in the 3D volume in the metal-polymer hybrid resin, wherein the metal-polymer hybrid resin includes (i) the first material having a metal component and (ii) the second material having a polymer component, a second optical assembly configured to: combine (i) a second UV beam from the second UV laser and (i) a second visible light beam from the second visible light laser, to form a second combined multi-spectral beam having both UV and visible light components, direct the second combined multi-spectral beam through the metasurface mask, or a second metasurface mask, to generate a second multi-spectral hologram beam, wherein the metasurface mask or the second patterned metasurface has a second pattern to form, as a second hologram, both (i) the first workpiece structure in the first material and the second workpiece structure in the second material, and direct the second multi-spectral hologram beam on the metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose the second hologram in the 3D volume in the metal-polymer hybrid resin, wherein the first material in the exposed 3D volume having been exposed by the first multi -spectral hologram beam and second multi-spectral hologram beam is heated to form a metallic structure within the 3D volume, and wherein the second material in the exposed 3D volume having been exposed by the first multi-spectral hologram beam and the second multi-spectral hologram beam is cured to form a polymer structure within the 3D volume.

[0039] In some aspects, the techniques described herein relate to a system further including: a third UV laser; a third visible light laser; a third optical assembly configured to: combine (i) a third UV beam from the third UV laser and (i) a third visible light beam from the third visible light laser, to form a third combined multi-spectral beam having both UV and visible light components, direct the third combined multi-spectral beam through the metasurface mask, or a third metasurface mask, to generate a third multi-spectral hologram beam, wherein the metasurface mask or the third metasurface mask has a third pattern to form, as a third hologram, both (i) the first workpiece structure in the first material and the second workpiece structure in the second material, and direct the third multi-spectral hologram beamon the metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose the third hologram in the 3D volume in the metal-polymer hybrid resin, wherein the first material in the exposed 3D volume having been exposed by the first multi-spectral hologram beam, the second multi-spectral hologram beam, and the third multi-spectral hologram is heated to form the metallic structure within the 3D volume, and wherein the second material in the exposed 3D volume having been exposed by the first multi-spectral hologram beam, the second multi-spectral beam, and the third multi-spectral hologram beam is cured to form the polymer structure within the 3D volume.

[0040] In some aspects, the techniques described herein relate to a system including: at least one UV laser, including a first UV laser; at least one visible light laser, including a first visible light laser; a metasurface mask having at least one patterned metasurface formed thereon, including a first patterned metasurface, wherein the first patterned metasurface has a first pattern for a first workpiece structure in a first material, wherein the first pattern forms a first hologram; a first optical assembly configured to: combine (i) a first UV beam from the first UV laser and (i) a first visible light beam from the first visible light laser, to form a first combined multi-spectral beam having both UV and visible light components, direct the first combined multi-spectral beam through a metasurface mask to generate a first multi-spectral hologram beam, wherein the first patterned metasurface has a first pattern to form, as a first hologram, both (i) a first workpiece structure in a first material and a second workpiece structure in a second material in a same 3D volume, and direct the first multi-spectral hologram beam on a metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose the first hologram in the 3D volume in the metal-polymer hybrid resin, wherein the metal-polymer hybrid resin includes (i) the first material having a metal component and (ii) the second material having a polymer component, wherein the first material in the exposed 3D volume having been exposed by the first multi-spectral hologram beam is heated to form a metallic structure within the 3D volume, and wherein the second material in the exposed 3D volume having been exposed by the first multi-spectral hologram beam is cured to form a polymer structure within the 3D volume.

[0041] In some aspects, the techniques described herein relate to a system including: at least one UV laser, including a first UV laser; at least one visible light laser, including a first visible light laser; at least one metasurface mask, including a metasurface mask having at least one patterned metasurface formed thereon, including a first patterned metasurface, wherein the first patterned metasurface has a first pattern for a first workpiece structure in a first material, wherein the first pattern forms a first hologram; a first optical assembly configured to: direct afirst UV beam from the first UV laser through a metasurface mask to generate a first hologram beam, wherein the first patterned metasurface has a first pattern to form, as a first hologram, a first workpiece structure in a first material; direct a first visible light beam from the first visible light laser through the metasurface mask, or a second metasurface mask, to generate a second hologram beam, wherein the metasurface mask, or the second metasurface mask, has a second pattern to form, as a second hologram, a second workpiece structure in a second material; direct the first hologram beam on a metal-polymer hybrid resin, to expose the first hologram in the 3D volume in the metal-polymer hybrid resin, wherein the metal-polymer hybrid resin includes (i) the first material having a metal component and (ii) the second material having a polymer component, wherein the first material in the exposed 3D volume having been exposed by the first hologram beam is heated to form a metallic structure within the 3D volume, and direct the second hologram beam on the metal-polymer hybrid resin, to expose the second hologram in the 3D volume in the metal-polymer hybrid resin, and wherein the second material in the exposed 3D volume having been exposed by the second multi-spectral hologram beam is cured to form a polymer structure within the 3D volume.

[0042] In some aspects, the techniques described herein relate to a system, further including a second UV laser and / or a second visible light laser.

[0043] In some aspects, the techniques described herein relate to a system, further including the second metasurface mask.

[0044] In some aspects, the techniques described herein relate to a system, further including: a controller configured to direct simultaneous projection of the first hologram and the second hologram in the 3D volume in the metal-polymer hybrid resin.

[0045] In some aspects, the techniques described herein relate to a system, further including: a controller configured to direct contemporaneous projection of the first hologram and the second hologram in the 3D volume in the metal-polymer hybrid resin.

[0046] In some aspects, the techniques described herein relate to a system, wherein the controller is configured to direct projection of the first multi-spectral hologram beam and the second multi-spectral hologram beam at a second location of the metal-polymer hybrid resin (e.g.. photocurable metal-polymer hybrid resin), to expose a third hologram and a fourth hologram in a second 3D volume in the metal-polymer hybrid resin.

[0047] In some aspects, the techniques described herein relate to a system, wherein the first material and the second material provide an integrated insulating and conducting structure having both an insulating structure and a conducting structure in the 3D volume.

[0048] In some aspects, the techniques described herein relate to a system, wherein the second material is cured to form the polymer structure within the 3D volume at a first rate, and wherein the first material is heated at a second rate to form the metallic structure within the cured polymer structure within the 3D volume, wherein the first rate is faster than the second rate.

[0049] In some aspects, the techniques described herein relate to a system, wherein the metallic structure includes an interconnect structure (e.g., redistnbution layer, e.g.. standard redistribution layer or freeform redistribution layer, e g., for multiple stacked IC chips, chiplets, active or passive components, etc., or for multiple IC chips, chiplets, active or passive components, combined in multiple orientations).

[0050] In some aspects, the techniques described herein relate to a system, wherein the metallic structure includes an interconnect structure, a routing structure (layout, vias), a portion of a ground plane, a portion of a passive electric component (capacitor, inductor), functionalized electric component (e.g., waveguide, antenna), thermal regulation component, or a combination of both.

[0051] In some aspects, the techniques described herein relate to a system, wherein the polymer structure is a dielectric that forms an interconnect supporting structure.

[0052] In some aspects, the techniques described herein relate to a system, wherein the polymer structure is a dielectric that supports the metallic structure.

[0053] In some aspects, the techniques described herein relate to a system, wherein the metal-polymer hybrid resin includes (i) a polymer, (ii) a silver ink (e g., metal-organic decomposition (MOD) silver precursor, e.g., upon UV absorption, the silver ions heat up, leading to decomposition of the silver complexes and formation of metallic silver), (iii) a visible light radical photoinitiator, and (iv) a UV light radical photoinhibitor (e.g., to prevent polymerization in the UV exposure regions, to allow only the silver metal to form in this region).

[0054] In some aspects, the techniques described herein relate to a system, wherein the UV light radical photoinhibitor includes bis[2-(o-chlorophenyl)-4,5-diphenylimidazole] (o-Cl- HABI).

[0055] In some aspects, the techniques described herein relate to a system, wherein the first optical assembly and the second optical assembly collectively provide exposure at sub- 500nm resolution (e.g., less than 500 nm, less than 100 nm, less than 10 nm) in a region of intersection or overlapping portion of the first multi-spectral hologram beam and the second multi-spectral hologram beam.

[0056] In some aspects, the techniques described herein relate to a system, wherein the first optical assembly and the second optical assembly collectively provide exposure at micrometer resolution. Example fabricated devices

[0057] In some aspects, the techniques described herein relate to an interconnect (e.g., redistribution layer device) including: an insulating structure; and a plurality' of metal wires (or conductive structure) formed by any one of the above-discussed methods or any one of the above-discussed systems.

[0058] In some aspects, the techniques described herein relate to an electrical device (e.g., passive component or active device, e.g., antenna module, antenna-in-package module, microprocessor, microcontroller, ASIC, Al chip) including: an insulating structure; and a plurality of metal wires (or conductive structure) formed by any one of the above-discussed methods or any one of the above-discussed systems.

[0059] In some aspects, the techniques described herein relate to an interconnect or electrical device, wherein the plurality of metal wires has a freeform 3D shape.

[0060] In some aspects, the techniques described herein relate to an interconnect or electrical device, wherein the plurality of metal wires includes a freeform curve wire.

[0061] In some aspects, the techniques described herein relate to an interconnect or electrical device, wherein the plurality' of metal wires form vias to form electrical connections across multiple layers in the interconnect or electrical device.

[0062] In some aspects, the techniques described herein relate to an interconnect or electrical device, wherein the plurality of metal wires form interconnects to form electrical connections across pins of the interconnect or electrical device.

[0063] In some aspects, the techniques described herein relate to a hybrid resin composition including: a resin including one or more monomers or prepolymers and optionally one or more crosslinkers; thermally decomposable metal precursor; and a photosystem including one or more photoinitiators.

[0064] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the resin includes one or more acrylate monomers or prepolymers, one or more epoxy monomers or prepolymers, one or more silicon monomers or prepolymers, or combinations thereof.

[0065] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the resin includes one or more acrylate monomers.

[0066] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the resin includes one or more monomers and / or one or more crosslinkersselected from 2-phenoxyethyl acrylate (PEA), isobomyl acrylate (IBOA), tripropyleneglycol diacrylate (TPGDA). trimethylolpropane triacrylate (TMPTA), or combinations thereof.

[0067] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the resin includes TPGDA and PEA.

[0068] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the resin includes TPGDA and PEA, wherein a ratio of TPGDA and PEA is from 3: 1 to 1 :3, more particularly 1 : 1.

[0069] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the one or more monomers or prepolymers and optionally one or more crosslinkers are present in the hybrid resin composition at a concentration from 20 wt % to 60 wt % based on a total weight of the hybrid resin composition.

[0070] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the thermally decomposable metal precursor includes a metal salt or a metal particle.

[0071] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the thermally decomposable metal precursor includes a silver salt, a gold salt, a copper salt, a nickel salt, or combinations thereof.

[0072] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the thermally decomposable metal precursor includes silver salt (including exemplary examples of silver nitrate, silver acetate, silver citrate, silver oxalate, and / or silver chloride) or silver particles.

[0073] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the thermally decomposable metal precursor includes a silver carboxylate salt, such as an alpha-substituted silver carboxylate salt, for example, silver neodecanoate.

[0074] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the thermally decomposable metal precursor is present in the hybrid resin composition at a concentration from 10 wt % to 20 wt % based on a total weight of the hybrid resin composition.

[0075] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the one or more photoinitiators are capable of initiating polymerization of the resin upon exposure to a first wavelength of light.

[0076] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the one or more photoinitiators are selected from benzoin ethers, benzilketals, a-dialkoxy -acetophenones, a-hydroxy-alkylphenones, a-amino-alkylphenones, acyl phosphine oxides, benzophenones / amines. thioxanthones / amines, titanocenes, or combinations thereof.

[0077] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the one or more photoinitiators are selected from 1-hydroxy-cyclohexyl- phenyl-ketone, a bisacylphosphine oxide (such as phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide). camphorquinone / amine (such as camphorquinone and ethyl 4- dimethylaminobenzoate), or combinations thereof.

[0078] In some aspects, the techniques described herein relate to a hybrid resin composition, further including one or more photoinhibitors, wherein the one or more photoinhibitors are capable of quenching the one or more photoinitiators under a second wavelength of light, wherein the second wavelength of light is different from the first wavelength of light, and wherein thermal decomposition of the thermally decomposable metal precursor is capable of occurring upon exposure to the second wavelength of light.

[0079] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the one or more photoinhibitors include a hexaaryl biimidazole (such as bis[2-(o-chlorophenyl)-4,5-diphenylimidazole], i.e., o-Cl-HABI).

[0080] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the one or more photoinitiators are capable of initiating polymerization of the resin only upon exposure to a first wavelength of light and a second wavelength of light, wherein the first wavelength of light and the second wavelength of light are different.

[0081] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the one or more photoinitiators include 2.3-butanedione.

[0082] In some aspects, the techniques described herein relate to a hybrid resin composition, wherein the hybrid resin composition further comprises a solvent, for example, terpineol.BRIEF DESCRIPTION OF THE DRAWINGS

[0083] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments and, together with the description, serve to explain the principles of the methods and systems.

[0084] Embodiments of the present invention may be better understood from the following detailed description when read in conjunction with the accompanying drawings.Such embodiments, which are for illustrative purposes only, depict novel and non-obvious aspects of the invention. The drawings include the following figures:

[0085] Figs. 1A, IB, 1C, ID, IE, and IF each show an example holographic metasurface lithography system configured to project a hologram having one or more different wavelengths of light onto a hybrid resin to simultaneously or concurrently cure / form both a first material structure and a second material structure from the hybrid resin in the same three-dimensional space in accordance with an illustrative embodiment.

[0086] Figs. 2A - 2D shows an example hybrid resin that may operate with the systems as described in relation to Figs. 1A, IB, 1C, and ID in accordance with an illustrative embodiment.

[0087] Figs. 3A - 3H show example metasurface masks and associated design and fabrication methods in accordance with an illustrative embodiment.

[0088] Figs. 4A and 4B show the operation of the holographic metasurface lithography system to generate a part using overlapping holograms in accordance with an illustrative embodiment.

[0089] Figs. 5 A and 5B each shows a method using UV and non-UV light for holographic metasurface nanolithography.

[0090] Fig. 6A shows an example method of fabrication using the exemplary holographic metasurface lithography operation, e.g., as described in relation to Fig. 1A - ID, 2A - 2D, 3A - 3F, 4A - 4B, 5A - 5B, in accordance with an illustrative embodiment.

[0091] Fig. 6B and 6C show an exemplary alignment system employed in the exemplary holographic metasurface lithography operation in accordance with an illustrative embodiment.

[0092] Figs. 7A, 7B, 7C, 7D, and 7E each shows examples of fabricated devices and components that can be fabricated using the method and system in accordance with an illustrative embodiment.

[0093] Figs. 8A, 8B, 8C, 8D, and 8E show experimental results associated with the development and evaluation of the holographic metasurface lithography operation in accordance with an illustrative embodiment. Specifically, Fig. 8A shows examples of material and structure formed of a structured metasurface hologram. Figs. 8B - 8E show an example AMME Printed Fan-Out Module with Embedded Chiplets and Passives that can be fabricated using the holographic metasurface lithography operation. Fig. 8E shows experiments in the fabrication of a freeform wire structure.

[0094] Figs. 9A, 9B, and 9C show process characterization results associated with the development and evaluation of the holographic metasurface lithography operation in accordance with an illustrative embodiment.

[0095] FIG. 10A provides images of the films produced using various monomer combinations after UV irradiation, as described in the examples. The monomer weight ratio in the resin formulation was fixed at 40%, and UV light-induced silver curing was accomplished using an intensity of 1.5 W / cm2.

[0096] FIG. 10B provides images of films with control of monomer ratio and addition of reactive acrylate-functionalized oligomers from Bomar (BR-741, BR-144B, and BDT-1015) as described in the examples. The monomer in the resin formulation is fixed as TPGDA:PEA(1 : 1) and UV silver curing was done at 1.5 W / cm2.

[0097] FIG. 10C provides SEM images as described in the examples of the conductive region generated by high-intensity UV (panel a) and the insulating region (panel b). SEM-EDS elemental mapping of silver and elemental spectrum (inset) of the conductive region (panel c) and the insulating region (panel d).

[0098] FIG. HA depicts components of an exemplary resin formulation.

[0099] FIG. 1 IB depicts an exemplary Silver + Polymer curing procedure showing that UV intensity' and wavelength can be used to create orthogonal curing conditions as described in the examples.

[0100] FIG. 11C depicts resin optimization using monomer mixes to control crosslinking density and polymer hardness, as described in the examples.

[0101] FIG. 11D depicts resin optimization using monomer concentrations to control crosslinking density and polymer hardness, as described in the examples.

[0102] FIG. 1 IE depicts SEM and EDS measurements of a 30 wt% polymer film showing polymer-dominated separation as described in the examples.

[0103] FIG. 1 IF depicts SEM and EDS measurements of a 20 wt% polymer film showing silver-dominated separation as described in the examples.

[0104] FIG. 12 provides images of films as described in the examples after 1) 470 nm irradiation (polymerization, red film) and 2) low-intensity UV irradiation. The intensity’ of UV was 10 mW / cm2for 4 mins (panel a) and 100 mW / cm2for 4 mins (panel c). The aged films (2 weeks, ambient conditions), (panel b), and (panel d), respectively, resulted in clearer bleaching.

[0105] FIG. 13 depicts the effect of radical species and additives on UV-induced polymerization and silver reduction using hybrid resins with noted compositions as described in the examples. A 365 nm UV irradiation time of 4 min was conducted with varying intensityof UV light exposure, resulting in qualitatively distinct reactions as observed by the color of the resulting films.

[0106] FIG. 14 depicts a transmission measurement experimental setup as described in the examples.

[0107] FIG. 15 provides data regarding transmittance vs. exposure time, as described in the examples. The blue dots are experimental data, and the black dashed line is the fitting result. The red dots are the calculated imaginary part of the sample’s refractive index k. The pink dashed line is the fitting result.

[0108] FIG. 16A provides (panel a) Schematic of the optical setup as described in the examples, (panel b) Photograph of the optical setup, (panel c) Photograph showing the test hologram mounted in the setup.

[0109] FIG. 16B provides data regarding (panel a) Select planes from the 3D light field projected by the hologram as recorded by the sensor with the axial locations noted, (panel b) Volumetric maximum intensity7projection of 3D light field, (panel a) shows planes selected from the central device in (panel b). (panel b) shows the volumetric light field produced by the 3x3 hologram array.

[0110] FIG. 16C provides (panel a) Schematic of the optical setup as described in the examples, (panel b) Photograph of the optical setup, (panel c) Spectrum of the LED measured using a spectrometer shows a bandwidth of ~ 14 nm.

[0111] FIG. 16D provides data regarding (panel a) Select planes from the 3D light field projected by the hologram as recorded by the sensor with the axial locations noted, (panel b) Volumetric maximum intensity7projection of 3D light field, (panel a) shows planes selected from the central device in (panel b). (panel b) shows the volumetric light field produced by the 3x3 hologram array.

[0112] FIG. 16E provides data regarding (panel a) Schematic of the optical setup as described in Section 2.2.5. (panel b) Select planes from the 3D light field projected by the hologram as recorded by the sensor with the axial locations noted, (panel c) Volumetric maximum intensity projection of 3D light field. Here, the data in each plane has been normalized to the maximum value in that plane.

[0113] FIG. 16F depicts an overlapping beam test to determine cure intensity7thresholds as described in the examples.

[0114] FIG. 16G provides a schematic of the 4F optical setup as described in the examples.

[0115] FIG. 16H provides images of a hollow cube hologram using the 4F optical setup with different magnifications.DETAILED DESCRIPTION

[0116] Some references, which may include various patents, patent applications, and publications, are cited in a reference list and discussed in the disclosure provided herein. The citation and / or discussion of such references is provided merely to clarify the description of the disclosed technology and is not an admission that any such reference is “prior art” to any aspects of the disclosed technology described herein. In terms of notation, “[n]” corresponds to the nth reference in the reference list. For example, Ref. [1] refers to the 1st reference in the list. All references cited and discussed in this specification are incorporated herein by reference in their entireties and to the same extent as if each reference was individually incorporated by reference.

[0117] Example System

[0118] Figs. 1A, IB, and 1C each show' an example holographic metasurface lithography system 100 (shown as 100a, 100b. 100c) configured to project a hologram 102 (also shown as 102’) having one or more different wavelengths of light onto a hybrid resin 104 to simultaneously or concurrently cure / form both (i) a first material structure 106, e.g., a metal structure and (ii) a second material structure 108, e.g., a polymer structure, from the hybrid resin 104 in the same three-dimensional space 110 in accordance with an illustrative embodiment. The holograms 102 are generated by metasurface masks 112 (shown as 112a, 1 12b) that each encodes spatial information for both the first material structure 106 (e.g., metal structure) and the second material structure 108 (e.g., polymer structure). In Fig. 1 A, two sets of holograms 102 projected on the hybrid resin 104 to cure / form the first material structure 106 and the second material structure 108 in the same three-dimensional space 110.

[0119] The hologram is a three-dimensional light field having interference patterns generated using diffraction. Optical holography employs lasers to generate the light field for an image (e.g., workpiece features) that has both depth and parallax to an original part feature. The metasurface mask can generate the hologram by overlaying a second wavefront, e.g., a reference beam, onto a wavefront of interest to generate the interference pattern that is then exposed to the hybrid resin (e.g., 104).

[0120] In the example shown in Fig. 1A, the system 100a includes (i) at least one UV laser 114 (shown as “first UV laser source” 114a and “second UV laser source “114b), at least one visible light laser 116 (shown as “first non-UV laser source” 116a and “second non-UV laser source” 116b), metasurface mask 1 12 (shown as first metasurface mask” 1 12a and secondmetasurface mask “112b), and optical assembly 118 (shown as “first optical assembly” 118a and “second optical assembly” 118b). The metasurface mask 112 has at least one patterned metasurface 118 (not shown; see Fig. 3 A) formed thereon, including a first patterned metasurface 118a and a second patterned metasurface 118b, each having a pattern (e.g., first pattern and second pattern) for a workpiece structure in a material. The first pattern and the second pattern each form a hologram.

[0121] The hybrid resin (e.g., 104) may include one or more monomers or prepolymers and optionally one or more crosslinkers, thermally decomposable metal precursor, and a photosystem comprising one or more photoinitiators. In Table 121, the UV laser source 114 (or sources) generates a UV light 122 (shown as 122’) that causes metal ions 124 in the hybrid resin 104 with or without photosystem to decompose and / or cure (125) to form the first structure 106, e.g., a metal structure. The non-UV laser source 116 (or sources) generates a non-UV light 126 (shown as 126’) that causes monomers 128 in the hybrid resin 104 with or without photosystem to cure to form the second structure 108, e.g., a polymer structure.

[0122] The optical assembly 118 includes a first optical assembly 118a and a second optical assembly 1 18b, each configured to combine (i) a respective UV beam 120 (shown as 120a, 120b) from the UV laser (e.g., 114a, 114b) and (i) a respective visible light beam 122 (shown as 122a, 122b) from the visible light laser (e.g., 116a, 116b), to form a combined multi- spectral beam 124 (shown as 124a, 124b) having both UV and visible light components. Each optical assembly 118 (e.g., 118a, 118b) directs the combined multi-spectral beam (e.g., 124a, 124b) through a respective metasurface mask (e.g., 112a, 112b) to generate a multi-spectral hologram beam 126 (shown as 126a, 126b). Each of the first patterned metasurface 112a and the second patterned metasurface 112b has a respective pattern to form, as a hologram (e.g., 102), both (i) a first workpiece structure 106 in a first material and a second workpiece structure 108 in a second material in a same 3D volume.

[0123] The metasurface mask (1 12a, 112b) may be formed on the same w afer or separate wafers that may be mounted on a metasurface gantry 134. The gantry7134 can allow the position of the wafer structure of the metasurface mask (112a, 112b) to be adjusted and / or aligned to optical assembly (e.g., 118a, 118b) or the build stage 128.

[0124] Each of the optical assembly 118 (e.g., 118a, 118b) directs the respective multi- spectral hologram beam (e.g., 126a, 126b) on the hybrid resin 104 (e.g., photocurable metal- polymer hybrid resin) to expose the two holograms (e.g., 102) in the 3D volume in the metal- polymer hybrid resin. The first material (e.g., metal ions or salt) in the exposed 3D volume having been exposed by the first multi-spectral hologram beam 126a and second multi-spectralhologram beam 126b is heated and / or decomposed / melted to form a metallic structure within the 3D volume. The second material (e.g., monomer) in the exposed 3D volume, having been exposed by the first multi-spectral hologram beam 126a and the second multi-spectral hologram beam 126b is cured to form the polymer structure 108 within the 3D volume. The structures (e.g., 106, 108) are formed on a build stage 128.

[0125] The intersection or overlapping portion of the first multi-spectral hologram beam and the second multi-spectral hologram beam can be controlled to generate the desired processing effect. Example configurations are shown in Table 1.Table 1

[0126] Controller. The optical assemblies 118a, 118b, laser systems (e.g., 114a, 114b, 116a, 116b), and motors and actuators of the build stage 128 may be controlled by one or more controllers 136. The controller 136 may store the instructions to execute the sequence of operation (e.g.. build instructions) for a given part or workpiece.

[0127] In some embodiments, the first and the second laser (e.g., 116a) are configured with laser diode having a peak wavelength or a wavelength distribution in the range of, for example and not limited to, 200-308 nm, 355 nm, 400 nm - 800 nm. e.g., 380 nm, 405 nm, 440 nm, 450 nm, 470 nm, 473 nm, 480 nm, 485 nm, 520 nm, 540 nm, 560 nm, 585 nm. 605 nm, 620 nm, 640 nm, 700 nm, 720 nm), 800 nm - 950 nm, 1000 nm (e.g., 1064 nm), 2 pm - 9 pm. In some embodiments, the range is greater than 10 pm. Examples of laser diodes include excimer laser, dye laser (e.g., argon-ionic laser, Ele-Ne laser), laser diode, Nd:YAG laser, Er:YAG laser, CO2 laser. For example, GalnP and AlGalnP-based laser diodes can generate a red laser, while GaN-based diodes can generate a blue laser. Other high-power lasers that can used include indium(III) phosphide, gallium(III) arsenide, and nanowire lasers.

[0128] The controller 136 as a computing system or interconnected machine logic circuits or circuit modules, or sets or modules thereof, may implement a sequence of computer- implemented acts or program modules. Accordingly, the logical operations described herein are referred to variously as state operations, acts, or modules. These operations, acts, and / or modules can be implemented in software, in firmware, in special purpose digital logic, in hardware, and any combination thereof. It should also be appreciated that more or fewer operations can be performed than shown in the figures and described herein. These operations can also be performed in a different order than those described herein.

[0129] The computer system is capable of executing the software components described herein for the exemplary method or systems. In an embodiment, the computing device may comprise two or more computers in communication with each other that collaborate to perform a task. For example, but not by way of limitation, an application may be partitioned in such a way as to permit concurrent and / or parallel processing of the instructions of the application. Alternatively, the data processed by the application may be partitioned in such a way as to permit concurrent and / or parallel processing of different portions of a data set by the computers. In an embodiment, virtualization software may be employed by the computing device to provide the functionality of a number of servers that are not directly bound to the number of computers in the computing device. In an embodiment, the functionality disclosed above may be provided by executing the application and / or applications in a cloud computing environment. Cloud computing may comprise providing computing services via a network connection using dynamically scalable computing resources. Cloud computing may be supported, at least in part, by virtualization software.

[0130] The processing unit may be a programmable processor that performs arithmetic and logic operations necessary for the operation of the computing device. While only one processing unit is shown, multiple processors may be present. As used herein, processing unit and processor refers to a physical hardware device that executes encoded instructions for performing functions on inputs and creating outputs, including, for example, but not limited to, microprocessors (MCUs), microcontrollers, graphical processing units (GPUs), and application-specific circuits (ASICs). Thus, while instructions may be discussed as executed by a processor, the instructions may be executed simultaneously, serially, or otherwise executed by one or multiple processors. The computing device may also include a bus or other communication mechanism for communicating information among various components of the computing device.

[0131] Computing devices may have additional features / functionalit '. For example, the computing device may include additional storage, such as removable storage and nonremovable storage. Computing devices of the controller may also contain network connection(s) that allow the device to communicate with other devices, such as over the communication pathways described herein.

[0132] Controller 136 operates with sensors, e.g., position sensors, pressure sensors, temperature sensors, motor sensors, to control the optical assemblies 118a. 118b. laser systems (e.g., 114a, 114b, 116a, 116b), and motors and actuators of the build stage 128. In some embodiments, the controller 136 operates with temperature sensors to monitor the temperature of the resin (e.g., 104) and level sensors to monitor the resin level.

[0133] In some embodiments, the controller 136 is configured to direct simultaneous projection of the first hologram and the second hologram in the 3D volume in the metal - polymer hybrid resin.

[0134] In some embodiments, the controller 136 is configured to direct contemporaneous projection of the first hologram and the second hologram in the 3D volume in the metal - polymer hybrid resin.

[0135] In some embodiments, the controller is configured to direct projection of the first multi-spectral hologram beam and the second multi-spectral hologram beam at a second location of the metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose a third hologram and a fourth hologram in a second 3D volume in the metal-polymer hybrid resin. The third and fourth holograms can be used to extend the fabrication of another portion of the workpiece.

[0136] Fabricated components. In having the multi-material fabrication capabilities via the system of Fig. 1A (among others), the fabricated components, e.g., the workpiece, may be an integrated insulating and conducting structure having both an insulating structure and a conducting structure.

[0137] The metallic structure (e.g., 106) may include an interconnect structure (e.g., redistribution layer, e.g., standard redistribution layer or freeform redistribution layer, e.g., for multiple stacked IC chips, chiplets, active or passive components, etc., or for multiple IC chips, chiplets, active or passive components, combined in multiple orientations). The metallic structure (e.g., 106) may include an interconnect structure, a routing structure (layout, vias), a portion of a ground plane, a portion of a passive electric component (capacitor, inductor), functionalized electric component (e.g.. waveguide, antenna), thermal regulation component, or a combination of both.

[0138] The polymer structure (e.g., 108) may be a dielectric that forms an interconnect supporting structure. The polymer structure (e.g., 108) may be a dielectric that supports the metallic structure.

[0139] Example Metal Polymer Hybrid Resin

[0140] Figs. 2A - 2D shows an example hybrid resin that may operate with the systems (e.g., 100a. 100b, 100c, lOOd) as described in relation to Figs. 1A, IB, 1C, and ID.

[0141] Fig. 2A shows an example of the hybrid resin (e.g.. 104) as a metal-polymer hybrid resin that can be subject to conductor (silver) curing and insulator (polymer) curing processes. Specifically, Fig. 2A, subpanel A shows a Jablonski diagram of a two-color, two- step polymerization reaction where molecules in the singlet ground state So are excited by blue light to an excited singlet state Si, followed by intersystem crossing (ISC) to the triplet ground state Ti. Molecules in the Ti state are then excited by red light to an excited triplet state Tnfrom which they form free radicals that induce polymerization [5], Fig. 2A, subpanel B shows UV induced thermal decomposition pathway for silver precursor chemistry.

[0142] In Fig. 2A, for the polymer curing, one metasurface created a blue hologram (e.g., 126a), and the other created a red hologram (e.g., 126b). Then, using a two-color, two-step resist shown in Fig. 2A ensured that the polymerization reaction only occurred where the two holograms overlap, referred to as cured voxel. For the silver curing, the two metasurfaces created overlapping UV holograms where the intensity of the UV light w as high enough to trigger the thermal decomposition of the metal salts in the area of overlap, referred to as thermally activated voxel. Additionally, because the polymerization reaction may be tuned to occur faster than the thermal decomposition reaction of the metal salts, the polymer may be used to limit the spatial extent of the metal formation during simultaneous curing of the multimaterial system, further increasing the resolution of the metal printing beyond the diffraction limit. Based on previous measurements of the reaction rates of the MOD inks and the two- color, two-step resists, it is estimated a volumetric cure of a 50 mm x 50 mm x 1 mm area can be performed in under 30 seconds, resulting in a volumetric throughput of greater than 80 mm3 / s.

[0143] Fig. 2B subpanel A shows the chemical platform, including major resin components comprising an acrylic monomer (tripropylene glycol diacrylate, TPGDA shown for reference) and silver ink that can be activated using UV light or heat to form conductive silver. Fig. 2B, subpanel B shows representative chemical structures for photoinitiators that activate with UV, violet, or blue light exposure and a UV-activated photoinhibitor and two- step (blue then red light) photoinitiator. Fig. 2B, subpanel C shows outcomes ofpolymerization-induced phase separation, where UV intensity results in the formation of continuous nanoporous channels filled with silver and visible light intensity results in a uniform insulating acrylic with isolated silver particles embedded within it.

[0144] Fig. 2D shows the results of the photosystem. Fig. 2D, subpanel A shows an example hy brid resin (e.g., 104) exposed with 365 nm in which no curing is expected. Results confirm the expected outcome. Fig. 2D, subpanel B shows an example hybrid resin (e.g.. 104) exposed with 365 nm in which no curing is expected. Results confirm the iBOA did not have a curing reaction. Fig. 2D, subpanel C shows the hybrid resin exposed with 470 nm laser in which current was expected. Results confirm the expected outcome.

[0145] Multi -Material Precursor for Printing Conductors and Insulators. To concurrently print insulators and conductors, a multi-wavelength activation / deactivation approach can be employed. By overlapping a beam of one wavelength, photoinitiation may be induced with a beam of a different wavelength in sub-diffraction volumetric polymerization [6].

[0146] The operation may employed for multicomponent resin comprising standard commercial acrylics, silver inks in an organic carrier solution, a visible light radical photoinitiator, and a UV light radical photoinhibitor. Bis[2-(o-chlorophenyl)-4,5- diphenylimidazole] (o-Cl-HABI) may serve as a potent radical photoinhibitor that can absorb UV light in the same range as the silver precursor salts. Thus, regions irradiated with UV light may simultaneously inhibit polymerization and activate the formation of pure silver domains. In neighboring regions, visible light may be used to activate the formation of a dielectric.

[0147] Previous studies suggested that the embedded silver salt precursors within the dielectric do not significantly alter its resistivity due to the lack of continuous silver and its overall low content (-10%) in the polymer matrix. To facilitate high-resolution fabrication, a three-color approach may be used with two visible wavelengths of light employed to activate polymerization within a voxel (volume element) via a two-step absorption process. Following the precedent for two-step absorption photocuring, 2,3-butanedione as the two-color two-step photoinitiator may be used that absorbs 440 nm light in the first step, followed by absorption of 660 nm in the second step required for polymerization.

[0148] Because small amounts of uncured monomer may be present in the silver domains, which may degrade the conductivity of the silver, to mitigate this risk, an orthogonal chemistry approach with polymerization-induced phase separation (PIPS) may be used to provide more pure domains of insulating polymer and conductive silver [7],

[0149] The precursor resin is highly viscous and thermally insulating, so the thermal fluxes are quite localized. The polymerization reaction also occurs much faster than the heating and thermal decomposition of the silver salts, so the resins are partially solidified before significant thermal fluxes are generated, limiting the migration of the precursors. Pulsed lasers may be employ ed to minimize thermal flux.

[0150] Simultaneous Multi-Material Printing of Conductors and Insulators. High- resolution printing of insulating and conducting structures may be achieved by creating orthogonal chemistries that are sensitive to different wavelengths of light and structuring the intensity and color of the light such that the correct chemistry is printed in the desired location.

[0151] Inverse design can structure the intensity of light in 3D across multiple wavelengths [8], In inverse design, the desired optical function / response may be first selected, and an algorithm is then applied to generate the optical design that can perform that function. A forward model of the electromagnetic fields produced by the patterned surface can be computed via scalar diffract on theory7or using more rigorous solutions of Maxwell’s equations. When the forward model is differentiable, then the inverse problem may be solved efficiently via machine learning or via adjoint methods. To solve this problem when the forward model is not differentiable (which may occur when photokinetic models with discontinuous functions are involved), a suite of iterative non-linear optimization algorithms [9] may be used.

[0152] Diffraction may limit the resolution; by exploiting a two-color, two-step polymerization process can improve the contrast and also enhance resolution in the 3D build space. Super-resolution patterning using a 2-color, multi-step process can be demonstrated, which is extensible to 3D

[0010] , Patterned metasurfaces may be employ ed to generate high- definition 3D intensity distributions of light at two distinct wavelengths, such that the chemistry is limited to the spatial overlap regions of these two wavelengths, as shown in Fig. 4.

[0153] In further aspects, a hybrid resin composition that can be used in the methods and systems described herein is also provided. In some aspects, the hybrid resin composition includes a resin. In some aspects, the resin comprises one or more monomers or prepolymers and, optionally, one or more crosslinkers. In additional aspects, the hybrid resin composition further includes a thermally decomposable metal precursor. In even further aspects, the hybrid resin composition may further include a photosystem.

[0154] In some aspects, the resin, as found in the hybrid resin composition, may comprise one or more acrylate monomers or prepolymers. In other aspects, the resin may comprise one or more epoxy monomers or prepolymers. In even further aspects, the resin may comprise oneor more silicon monomers or prepolymers (such as oligosiloxanes or the like). In further aspects, the resin may comprise a combination of any of the above monomers or prepolymers.

[0155] In some particular aspects, the resin comprises one or more acrylate monomers. Representative examples of suitable acrylate monomers include but are not limited to, acrylic acid, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, butyl acrylate, hydroxyethyl acrylate, phenoxy ethyl acrylate, 1.6-hexanediol diaciylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, methacry lic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, glycidyl methacry late, ethylene glycol dimethacrylate, methyl 2-cyanoacrylate, ethyl 2-cyanoacrylate, n-butyl cyanoacrylate, octy l cyanoacry late, 2-octyl cyanoacrylate, and isobutyl cyanoacrylate. In some particular aspects, the one or more acrylate monomers may’ comprise 2-phenoxyethyl acrylate (PEA), isobomyl acrylate (IBOA), or combinations thereof. In some particular aspects, the one or more acrylate monomers may comprise PEA.

[0156] In some aspects, the resin, as found in the hybrid resin composition, may optionally comprise one or more crosslinkers. A suitable crosslinker may be selected based on the choice of one or more monomers or prepolymers as found within the resin composition. For example, suitable crosslinkers may include diacrylates, triacrylates, tetracrylates, polyamines, anhydrides, polyphenols, polythiols, or the like. In some aspects, the one or more crosslinkers may comprise tripropyleneglycol diacrylate (TPGDA), trimethylolpropane triacrylate (TMPTA), or combinations thereof. In some particular aspects, the one or more crosslinkers may comprise TPGDA.

[0157] In some aspects, the one or more monomers or prepolymers and optionally one or more crosslinkers are present in the hy brid resin composition at a concentration from 20 wt % to 60 wt % based on a total weight of the hybrid resin composition, including exemplary values of 20 wt %, 25 wt %, 30 wt %, 35 wt %, 40 wt %, 45 wt %, 50 wt % 55 wt %, 60 wt %, or any subrange formed from the above exemplary values. In some particular aspects, the one or more monomers or prepolymers and optionally one or more crosslinkers are present in the hybrid resin composition at a concentration of 30 wt % based on a total weight of the hybrid resin composition.

[0158] As used herein, the term “thermally decomposable metal precursor” refers to a component that, upon thermal exposure, decomposes into a metal, e.g., a conductive metal such as silver, copper, gold, or nickel. In some aspects, the thermally decomposable metal precursor may comprise a metal salt, such as but not limited to silver salts, gold salts, copper salts, nickel salts, or combinations thereof. In some particular aspects, the thermally decomposable metalprecursor may comprise a metal particle, such as silver particles, gold particles, copper particles, nickel particles, and the like. In some particular aspects, the thermally decomposable metal precursor may comprise a silver salt, including examples such as silver nitrate, silver acetate, silver citrate, silver oxalate, and / or silver chloride. In some more particular aspects, the thermally decomposable metal precursor may comprise a silver carboxylate. In some more particular aspects, the thermally decomposable metal precursor may comprise silver neodecanoate.

[0159] In some aspects, the thermally decomposable metal precursor is present in the hybrid resin composition at a concentration from 10 wt % to 20 wt % based on the total weight of the hybrid resin composition, including exemplary values of 10 wt %, 11 wt %, 12 wt %, 13 wt %, 14 wt %, 15 wt %, 16 wt %. 17 wt %, 18 wt %, 19 wt %, 20 wt %. or any subrange formed from the above exemplary values.

[0160] Example Hybrid Resin

[0161] In some aspects, the photosystem as found in the hybrid resin composition may comprise one or more photoinitiators. In some aspects, the one or more photoinitiators are capable of initiating polymerization of the resin upon exposure to a first wavelength of light. Suitable types of photoinitiators include, but are not limited to, benzoin ethers, benzil ketals, a-dialkoxy-acetophenones, a-hydroxy-alkylphenones, a-amino-alkylphenones, acyl phosphine oxides, benzophenones / amines. thioxanthones / amines, titanocenes, or combinations thereof. For example, the photoinitiator may be selected from acetophenone, asinoin, anthraquinone, anthraquinone 2-sulfonic acid (or salts thereof), (benzene) tricarbonylchromium, benzil, benzoin, benzoin ethyl ether, benzoin isobutyl ether, benzoin methyl ether, benzophenone, 3,3’.4.4’-benzophenonetetracarboxylic acid dianhydride, 4- benzoylbiphenyl, 2-benzyl-2-(dimethylamino)-4'-morpholinobulyrophenone. 4,4’- bis(diethylamino)benzophenone, 4,4’-Bis(dimethylamino)benzophenone, camphorquinone, 2- chlorothioxanthen-9-one, (cumeme) cyclopentadienyl iron(II) hexafluorophosphate, dibenzosuberenone, 2,2-diethoxyacetophenone, 4,4’-dihydroxybenzophenone, 2,2-dimethoxy- 2-phenylacetophenone, 4-(dimethylamino)benzophenone, 4.4'-dimethylbenzil, 2,5- dimethylbenzophenone, 3,4-dimethylbenzophenone, 4’ -ethoxy acetophenone, ethylanthroquinone, ferrocene, 3 ’-hydroxy acetophenone, 4’-hydroxyacetophenone, 3- hydroxybenzophenone, 4-hydroxybenzophenone, 1 -hydroxy cyclohexyl phenyl ketone, 2- hydroxy -2 -methylpropiophenone, 2-methylbenzophenone, 3-methylbenzophenone, methylbenzoyl formate, 2-methyl-4’ -(methylthio)-2-morpholinopropiophenone, phenanthrenequinone, 4’ -phenoxy acetophenone, thioxanthene-9-one, triarylsulfoniumhexafluoroantimonate salts, triarylsulfonium hexafluorophosphate salts, or combinations thereof. In some exemplary aspects, the one or more photoinitiators are selected from 1- hydroxy-cyclohexyl-phenyl-ketone, a bisacylphosphine oxide (such as phenylbis(2,4,6- trimethylbenzoyl)phosphine oxide), camphorquinone / amine (such as camphorquinone and ethyl 4-dimethylaminobenzoate), or combinations thereof.

[0162] In some aspects, the photosystem, as found in the hybrid resin composition described herein, may further comprise one or more photoinhibitors. In some aspects, the one or more photoinhibitors are capable of quenching the one or more photoinitiators under a second wavelength of light, wherein the second wavelength of light is different from the first wavelength of light. In some aspects, the thermal decomposition of the thermally decomposable metal precursor is capable of occurring upon exposure to the second wavelength of light. A representative but non-limiting example of photoinhibitors that may be used include hexaaryl biimidazoles, such as bis[2-(o-chlorophenyl)-4,5-diphenylimidazole], i.e., o-Cl- HABI).

[0163] In some aspects, the one or more photoinitiators are capable of initiating polymerization of the resin only upon exposure to a first wavelength of light and a second wavelength of light, wherein the first wavelength of light and the second wavelength of light are different. A representative but non-limiting example of a photoinitiator that can be used in such an aspect includes 2,3-butanedione.

[0164] Additional Examples of Systems

[0165] Figs. IB and 1 C each show an example holographic surface lithography system 100 (shown as 100b, 100c). The subcomponents shown in Figs. IB and 1C can be similar to those employed in the system of Fig. 1A, among other components described herein. The systems 100b, 100c employ holograms to form 3D or 2D structures on a part or as a part. In some embodiments, the systems 100b, 100c can be implemented for large-scale printing (e.g., for photovoltaic components, interconnects, or electrical components for electronics).

[0166] In Fig. IB, the holographic surface lithography system 100b includes a single laser projection system. The system 100b includes a UV laser source 114. a non-UV laser source 116, and an optical assembly 118 that combines outputs of the laser sources 114, 116 to project a combined laser beam 124 to a metasurface mask 112 to project a holographic laser beam 126 onto a hybrid resin 104 to cure / form a part on a build stage 128.

[0167] In Fig. 1C, the holographic surface lithography system 100c, the UV laser source 114, the non-UV laser source 116, and two optical assemblies 118 (shown as 118c, 118d) project the laser beams 124 (shown as 124c, 124d) to a metasurface mask 1 12 (shown as 112c,112d) to project a holographic laser beam 126 (shown as 126c, 126d) onto the hybrid resin 104 to cure / form a part on a build stage 128.

[0168] The systems 100b, 100c can employ a controller 136 to operate the laser, optical subassembly, and actuators as described in relation to Fig. 1 A.

[0169] In some embodiments, the system (e.g., 100a, 100c) includes a third UV laser, a third visible light laser, and a third optical assembly configured to combine (i) a third UV beam from the third UV laser and (i) a third visible light beam from the third visible light laser, to form a third combined multi-spectral beam having both UV and visible light components. The third optical assembly can direct the third combined multi-spectral beam through the metasurface mask, or a third metasurface mask, to generate a third multi-spectral hologram beam, wherein the metasurface mask or the third metasurface mask has a third pattern to form, as a third hologram, both (i) the first workpiece structure in the first material and the second workpiece structure in the second material. The third optical assembly can direct the third multi-spectral hologram beam on the metal-polymer hybrid resin (e.g., photocurable metal- polymer hybrid resin), to expose the third hologram in the 3D volume in the metal-polymer hybrid resin.

[0170] Example Holographic Nanolithographv System with Improved Resolution

[0171] Fig. ID shows an example holographic surface nanolithography system 100 (shown as lOOd) based on the holographic metasurface lithography described in relation to Fig. 1A. The subcomponents shown in Fig. ID can be employed in any one of the systems of Figs. 1 A - 1 C, among other components described herein.

[0172] The holographic surface nanolithography system lOOd is configured to project a hologram (e.g., 102) (having one or more different wavelengths of light onto a hybrid resin (shown as “Resin vat” 104”) to simultaneously or concurrently cure / form both (i) a first material structure (e.g., a metal structure 106) and (ii) a second material structure (e.g., a polymer structure 108), from the hybrid resin 104” in the same three-dimensional space 110 in accordance with an illustrative embodiment. In this example of Fig. ID, two sets each of one or more holograms (e.g., 102) are projected into a resin vat 104” having a component 136 (shown as chip 136) to form multi-material structures (collectively shown as 140) having the components 106, 108 that is integrated with an existing component 136.

[0173] The system 100b utilizes sub-wavelength-pattemed metasurface masks to create precisely aligned, overlapping, multicolored holograms for the simultaneous high-resolution curing of both conductors and insulators in a hybrid metal-polymer resin. The meta-surfaces are multiplexed so that different holograms are formed from the same surface when exposedto UV or visible light, allowing overlapping multicolored holograms to be created simultaneously.

[0174] The independent overlap of holograms coming from different angles ensures the resolution in the z-direction of volumetric 3D printing. Generally, z-direction resolution can be set by how well the resin absorbs the light, but to propagate the light deep into the resin to make large volumetric structures, the resin should have low light absorption, which may limit z resolution. By creating perpendicular, overlapping holograms where the material only cures in the overlapping region, however, the system 100b may achieve finer resolution (e.g., sub- 500nm resolution) on all axes.

[0175] In the example shown in Fig. ID, the holograms (e g., 102) are generated by metasurface masks 112a, 112b (shown as “Metasurface #1” 112a’, “Metasurface #2” 112b’) that each encodes spatial information for both the first material structure 106 (e.g., metal structure) and the second material structure 108 (e.g., the polymer structure) for the additively manufactured structure 140. The system lOOd includes (i) a first UV laser source 114a (shown as "‘365 nm” 114a’ as high power UV laser for thermal curing conductor), a second UV laser source 114b (shown as “365 nm” 114b’ as high power UV laser for thermal curing conductor). afirst non-UV laser source 116a (shown as “440 nm” blue laser 116a’ for polymerization), and a second non-UV laser source 116b (shown as “660 nm” red laser 116b’ for polymerization), a first optical assembly 118a (shown as 118a'), and a second optical assembly” 118b (shown as 118b’).

[0176] The metasurface mask 1 12a’, 112b’ each has at least one patterned metasurface 118 formed thereon, including a first patterned metasurface and a second patterned metasurface, each having a pattern (e.g., first pattern and second pattern) for a workpiece structure in a material. The first pattern and the second pattern each form a hologram.

[0177] Each of the optical assemblies 118a’, 1 18b’ directs a respective multi-spectral hologram beam 126a, 126b (shown as 126a’, 126b’) on the hybrid resin 104” (e.g., photocurable metal-polymer hybrid resin) to expose the two holograms (e.g., 102) in the 3D volume in the metal-polymer hybrid resin. The first material (e g., metal ions or salt) in the exposed 3D volume having been exposed by the first multi-spectral hologram beam 126a and second multi-spectral hologram beam 126b is heated and / or decomposed / melted to form a metallic structure within the 3D volume. The second material (e.g., monomer) in the exposed 3D volume, having been exposed by the first multi-spectral hologram beam 126a and the second multi-spectral hologram beam 126b is cured to form the polymer structure 108 within the 3D volume. The structures (e.g., 106, 108) are formed on a build stage 128 (shown as “X-Y-Z-0 Nanopositioning System'’ 128’). The intersection or overlapping portion of the first multi-spectral hologram beam 126a and the second multi-spectral hologram beam 126b can provide for the area of curing voxel.

[0178] To generate the multi-spectral hologram beams 126a, 126b, each of the optical assemblies 118a’, 118b' combines (i) a respective UV beam 120a, 120b (shown as 120a’, 120b’) from the UV laser 114a’, 114b’ and (i) a respective visible light beam 122a, 122b (shown as 122a’, 122b’) from the visible light laser 116a’, 116b’, to form a combined multi- spectral beam 124a, 124b (shown as 124a’, 124b’). The optical assemblies 118a’, 118b’ direct the combined multi-spectral beam, e.g., 124a’, 124b' through a respective metasurface mask 112a’, 112b’ to generate the multi-spectral hologram beam 126a’, 126b’. Each of the first patterned metasurface 112a and the second patterned metasurface 112b has a respective pattern to form, as a hologram (e.g., 102), both (i) a first workpiece structure 106 in a first material and a second workpiece structure 108 in a second material in a same 3D volume.

[0179] Each of the optical assemblies 118a' includes the UV laser (e.g., 114a’ or 114b’) and non-UV laser (e.g., 116a’ or 116b’). The UV light 120a’ and non-UV light 122a’ are each directed through a shutter 142, 144 and combined via a minor (shown as mirror “M7”) and directed through a respective first lens “LI” through a pinhole to a second lens “L2”. The combined light is then redirected via a first mirror (shown as “Ml”, “M4”) and a second mirror (shown as “M2”. “M5”) to an alignment gimble 146 (shown as 146a, 146b).

[0180] Fig. ID shows an example alignment submodule 148 (shown as 148a, 148b) for the metasurface and build stage 128’. In Fig. ID, each of the alignment submodules 148a, 148b includes a reference gating 150, 152 (shown as 150a, 150b, 152, 152b) fabricated on the metasurface mask substrate 154 and an alignment plate 151 of the build stage 128’, respectively. The alignment submodules 148a, 148b include lasers 156a. 156b (shown as 156a), optical assemblies 158a, 158b (shown as 158a), and detectors 160a, 160b (shown as 160a). For each alignment assembly, the laser 156 directs an alignment laser beam to the optical assembly 158 that is directed to each of the reference grating 150 of the metasurface substrate 154 and the reference grating 152 of the building stage alignment plate 151 and then to the detector 160. The detector 160, as its associated controller, can determine the error between the alignment grating to direct controls of the building stage 128’ (in this example).

[0181] To improve the curing resolution, the system lOOd is shown with a UV laser that can generate a UV laser beam 162 to be projected onto the resin 104”. The low-power UVlaser creates a polymerization dead zone where polymerization does not occur since the UV light prevents it. This helps the part not stick to the build window.

[0182] Fig. IE shows another configuration of the holographic surface nanolithography system 100 (shown as lOOe). In Fig. IE, the optical assembly and metasurface masks are configured for the light to pass through the metasurface masks (shown as 112a” and 112b”) non-angularly, perpendicularly to the metasurface masks 112a” and 112b”.

[0183] Fig. IF shows yet another configuration of the holographic surface nanolithography system 100 (shown as 1000. In Fig. IF, the alignment gimbles 146 (shown as 146a and 146b) are (i) placed above the metasurface mask substrate 154 and (ii) optically coupled to one or more lenses (shown as “L3” and “L4”) to direct a respective multi-spectral hologram beam 126a, 126b on the hybrid resin 104 (e.g.. photocurable metal-polymer hybrid resin) to expose the two holograms (e.g., 102 in Fig. 1 A) in the 3D volume 110 in the metal- polymer hybrid resin. The additional lenses “L3” and ‘14” allow" for adjustment for focal length for the projections.

[0184] Metasurface Mask Design and Fabrication

[0185] Figs. 3A - 3F show example metasurface masks and associated design and fabrication methods in accordance with an illustrative embodiment. As noted above, multiple holographic beams, e.g., 2, 3, 4, etc., can be projected into the resin at a single location to improve the curing / processing time for the metal and polymer structure or to improve the resolution of the structures. Figs. 3A - 3C each shows examples of the metasurface masks that can be employed in the exemplary system, e.g., as described in relation to Figs. 1 A - ID.

[0186] Fig. 3A shows a metasurface mask 112 formed on a wafer to generate a holographic projection, e.g., forthe system of Fig. IB. The wafer is shown to include alignment features.

[0187] Fig. 3B shows two metasurface masks (e.g., 112a, 112b) formed on a wafer to generate two holographic projections, e.g., for the system of Fig. 1A, 1C, and ID.

[0188] Fig. 3C shows three metasurface masks (e.g., 112a, 112b, 112c) formed on a wafer to generate three holographic projections. The first metasurface mask can operate with a first optical assembly and laser system. The second metasurface mask can operate with a second optical assembly and laser system. The third metasurface mask can operate with a third optical assembly and laser system. The multiple holograms, e.g., 2, 3, 4, 5, etc., can be simultaneously or concurrently projected where the intersection or overlapping portion of the multi-spectral hologram beams can be controlled to generate a desired processing effect.

[0189] Example fabrication processes for metasurface can be found in Mohammad, N., Meem, M., Wan, X. and Menon, R., Sci Rep 7, 5789 (2017), Allen, Marshall J., et al. "Multimorphic materials: spatially tailoring mechanical properties via selective initiation of interpenetrating polymer networks." Advanced Materials 35.9 (2023): 2210208, and Andrew, Trisha L., Hsin-Yu Tsai, and Rajesh Menon. "Confining tight to deep subwavelength dimensions to enable optical nanopatteming." Science 324.5929 (2009): 917-921, which are incorporated by reference herein.

[0190] Design process. Figs. 3D - 3E shows example design process 300 (shown as 300a and 300b) for a metasurface mask. In some embodiments, an inverse design algorithm is applied to a 3D object and an optical function / response (e.g., slice) to generate the metasurface that can perform such function on the 3D object. Software tools with the angular-plane-wave- spectrum method may be combined with partial differential equations that account for scattering and absorption due to photoreactions to simulate the metasurface mask fabrication process.

[0191] In Figs. 3D and 3E. the design process 300 (shown as 300a, 300b) for generating a hologram, and corresponding metasurface mask (e.g.. 112), for a workpiece includes providing (302) a model for a 3D object 304 (shown as 3D object file 304’) (e.g., interconnect, semiconductor device, etc.), converting (306) the model 304 into a plurality of slices 308 (shown as “Sliced Image at multiple planes'’ 308'), and applying (310) the inverse design algorithm (312) to the plurality of slices (308) to generate (314) the metasurface profile / topologies (e.g., 112) for the hologram (e.g., 102). Inverse design is a computational method to automate the process of designing photonic devices where the desired performance is framed as a mathematical optimization problem that is found by the computer. Figs. 3G and 3H show an example of a sliced object 308 having been sliced at two orientations corresponding to the expected holographic beam exposure.

[0192] To address scattering, a photokinetic rate reaction model can be incorporated into the forward model for the inverse design method to account for absorption in the resin and scattering that would be created by changes in the resin properties or the chip interface.

[0193] To design a metasurface with sufficient degrees of freedom, a forward angular- plane-wave-spectrum (APWS) optical model may be implemented in a massively parallel fashion. The APWS may be implemented via two FFTs and one inverse FFT to compute across massively parallel, distributed memory' architectures.

[0194] Simulation (315) of the generated metasurface mask can be performed (shown as “Characterization” 315), e.g., via the angular-plane-wave-spectrum method combined withpartial differential equations to account for scattering and absorption. The lithography operation (316) can be performed per the system described in relation to Figs. 1A - ID or method as described in relation to Figs. 5 A - 5B, among others herein, to generate (shown as “Develop” 318) the formed part having the first material structure (e.g., 106) and second material structure (e.g., 108).

[0195] In Fig. 3E, the incidence of UV and non-UV light simulation 319 can be used to generate an initial hologram 328. The simulated scattering and absorption effects can be determined via operators 320, 322, which determine the scalar diffraction (320) and the intensity of the exposure at the multiple planes (322). The error 323 (show n as “MSE” 323) between the 3D target (324) and the intensity profile for the multiple planes from operators 320, 322 can then be used to update (326) the generated hologram 102 (shown as 328).

[0196] Fabrication process. Fig. 3F shows an example metasurface mask (e.g., 112) and the associated method of fabricating the metasurface mask (e.g., 112) on a wafer. Fig. 3F, subpanel A shows example steps to form the metasurface mask in a wafer by forming (330) a multi-level pattern in photoresist 332 on a substrate 333 (shown as “fused silica” 333), etching (334) the photoresist, e.g.. via reactive-ion etching, to form the pattern 336. Fig. 3F. subpanel C, shows an image of a grayscale metasurface mask fabricated with voxels down having 100 nm features. The voxel includes 4096 levels fabricated using two-photon lithography processes. Fig. 3F, subpanel B, shows the design of the metasurface mask.

[0197] Example Operation with Overlapping Hologram

[0198] Super-resolution, e.g., of the voxels of the hologram, may be achieved by overlapping two holograms. Fig. 4A shows the conductor (silver) curing and insulator (polymer) curing resulting from exposure by overlapping holograms (e.g., 102). In Fig. 4A, for the conductor curing 401, the overlapping UV holograms 402 can generate an intensity of the UV light sufficiently high to trigger, e.g., the thermal decomposition of the metal salts in the hybrid resin (e.g., 104) in the 3D space of overlap, referred to as thermally activated voxel 404. For the polymer / insulator curing 403, one metasurface can create a first hologram 406 (shown as blue hologram 406), and another metasurface can create the second hologram 408 (shown as red hologram 408). At the intersection of the holograms 406, 408. at two-color, a two-step resist process occurs to ensure that the polymerization reaction only occurs where the two holograms overlap, referred to as cured voxel 410.

[0199] In some embodiments, the region of intersection or overlapping portion of the first multi-spectral hologram beam and the second multi-spectral hologram beam can provideoverlapping exposure at higher resolution, e.g., for smaller features, than can be provided by a single hat sub-500nm resolution (e.g., less than 500 nm, less than 100 nm, less than 10 nm).

[0200] In some embodiments, the region of the intersection or overlapping portion of the first multi-spectral hologram beam and the second multi-spectral hologram beam can provide exposure over large regions, e.g., at micrometer resolution.

[0201] The numerical aperture of the metasurface may be defined per Equation 1 :(Eq. 1)

[0202] The resolution of the overlapping holograms may be calculated per Equation 2.0.61 xy resolution = -NA(Eq. 2)

[0203] Fig. 4B shows an embodiment of the exemplary HMNL process where the first visible light is 440 nm, the second visible light is 660 nm, and the UV light is 365 nm. Using Equations 1 and 2 (with NA = 0.9), the lateral resolution of light beams for UV light (365 nm), blue light (440 nm). and red light (660 nm), can be determined as 247 nm, 298 nm, and 447 nm respectively.

[0204] Rate Tuning to use Co-Exposed Material as Support

[0205] The polymerization reaction may be tuned to occur faster than the thermal decomposition reaction of the metal salts such that the polymer may be used to limit the spatial extent of the metal formation during simultaneous curing of the multi-material system, further increasing the resolution of the metal printing beyond the diffraction limit.

[0206] In some embodiments, the chemistry hybrid resin can be tuned such that the second material (e.g., monomer) is cured to form the polymer structure within the 3D volume at a first rate, and the first material (e.g., metal ions or salt) is heated at a second rate slower than the first rate to form the metallic structure within the cured polymer structure within the 3D volume.

[0207] In other embodiments, the power level and / or exposure / run time of the UV laser and non-UV laser may be configured, e.g., the non-UV light having a higher power level or duty cycle than the UV light at the first portion of the holographic exposure while the UV light power level of duty' cycle is increased for the second, later portion of the holographic exposure.

[0208] Example Method of Holographic Metasurface Lithography

[0209] Figs. 5A and 5B each shows an example method of projecting a hologram having two or more different wavelengths of light (one UV and one non-UV, e.g., visible light) onto a hybrid resin to simultaneously or concurrently cure / form both (i) a first material structure, e.g., a metal structure and (ii) a second material structure, e.g., a polymer structure, from the hybrid resin in the same three-dimensional space.

[0210] Example Method #7. Fig. 5 A shows a method 500 (show n as 500a) using UV and non-UV light (e.g., visible light beams) for holographic metasurface nanolithography. The method 500a includes combining (502), via an optics assembly (e.g., 118a, 118b), a first UV beam (e.g., 120a), and a first non-UV beam (e.g., 122a) to form a first combined multi-spectral beam (e.g., 124a) having both UV and non-UV spectral components.

[0211] The method 500a then includes combining (504). via a second optics assembly (e.g., 118b), a second UV beam (e.g., 114b), and a second non-UV beam (e.g., 116b) to form a second combined multi-spectral beam (e.g., 124b) having both UV and non-UV components. The second non-UV beam (e.g., 122b) may be the same or different from the first non-UV beam (e.g.. 116a).

[0212] The method 500a then includes directing (506) the first combined multi-spectral beam (e.g., 124a) through a first metasurface mask (e.g., 112a) with patterned metasurface to generate a first multi-spectral hologram beam (e.g., 126a) as w ell as directing (508) the second combined multi-spectral beam (e.g., 124b) through a second metasurface mask (e.g., 112b) with patterned metasurface to generate a second multi-spectral hologram beam (e.g.. 126b).

[0213] The first patterned metasurface (e.g., 1 12a) has a first pattern for a first workpiece structure (e.g., 106) in a first material and a second workpiece structure (e.g., 108) in a second material. The first pattern forms a first hologram. The second patterned metasurface (e.g., 112b) has a second pattern for the first workpiece structure (e.g., 106) in the first material and the second workpiece structure (e.g., 108) in the second material. The second pattern forms a second hologram.

[0214] The first multi-spectral hologram beam (e.g., 126a) and the second multi-spectral hologram beam (e.g., 126b) may be simultaneously or contemporaneously projected on a metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), e.g.. as described in relation to Figs. 2A - 2D to expose a first hologram and a second hologram in a 3D volume in the metal-polymer hybrid resin, which forms a metallic structure within the 3D volume and a polymer structure within the 3D volume.

[0215] The term "simultaneously projected" refers to the first multi-spectral hologram beam (e.g., 126a) and the second multi-spectral hologram beam (e.g., 126b) being projectedonto the resin in at least an overlapping manner. The overlapped in the projection can be, for example, for 10% of the exposure time, 20% of the exposure time, 30% of the exposure time, 40% of the exposure time, 50% of the exposure time, 60% of the exposure time, 70% of the exposure time, 80% of the exposure time, 90% of the exposure time, 100% of the exposure time.

[0216] The term “contemporaneously projected” refers to the first multi-spectral hologram beam (e.g., 126a) and the second multi-spectral hologram beam (e.g.. 126b) being projected onto the resin in a sequence to have an effect in the curing but in an overlapping manner.

[0217] In some embodiments, the first non-UV beam (e.g., 122a) (having at least one visible light beam) from the first laser (e.g., 116a) is a first visible light (referred to as 122a’), and the second non-UV beam (e.g., 122b) (having at least one visible light beam) from the second laser (e.g., 116b) is a second visible light (referred to as 122b’). The first visible light 122a’ has the same spectral component, e.g.. wavelength distribution, as the second visible light 122b’.

[0218] In some embodiments, the first non-UV beam (e.g., 122a) (having at least one visible light beam) from the first laser (e g., 116a) is a first visible light, and the second non- UV beam (e.g., 122b) (having at least one visible light beam) from the second laser (e.g., 116b) is a second visible light. The first visible light 122a’ has a different spectral component, e.g., wavelength distribution, as the second visible light 122b’.

[0219] In some embodiments, the second material (e.g., 108) is cured to form the polymer structure within the 3D volume at a first rate, and the first material (e.g., 106) is heated / decomposed / melted at a second rate (faster than the first rate) to form the metallic structure within the cured polymer structure within the 3D volume.

[0220] Example Method #2. Fig. 5B shows another method 500b for holographic metasurface nanolithography. The method 500b includes directing (512) a first beam (e.g., 120a) having a UV component through a first metasurface mask (e.g., 112a) having a first patterned metasurface to generate a first hologram beam.

[0221] The method 500b then includes directing (514) a second beam (e.g., 120b) having a visible light component through a second metasurface mask (e g., same metasurface mask at different regions or different metasurface masks) with a second patterned metasurface to generate a second hologram beam.

[0222] The method 500b then includes simultaneously or contemporaneously projecting (516) the first hologram beam and the second hologram beam on a metal-polymer hybrid resin(e.g., photocurable metal -polymer hybrid resin) to expose the first hologram and the second hologram in the same 3D volume in the metal-polymer hybrid resin, to form a metallic structure within the 3D volume and a polymer structure within the 3D volume.

[0223] Example Method of Fabrication

[0224] Fig. 6A shows an example method 600 of fabrication using the exemplary holographic metasurface lithography operation, e.g., as described in relation to Fig. 1A - ID, 2A - 2D. 3A - 3F. 4A - 4B. 5A - 5B. among others. As shown in the example shown in Fig. 6A, the method 600 includes generating (602) an inverse metasurface mask design, e.g., as described in relation to Figs. 3D and 3E. Method 600 additionally includes preparing (604) the resin (e.g., 104) (shown as “Vat preparation’" 604) and fabricating (606) the holographic mask (e.g.. 112).

[0225] Method 600 additionally includes performing (608) the holographic metasurface lithography operation (e.g., 102), e.g., as described in relation to Fig. 1 A - ID, 2A - 2D, 3A - 3F, 4A - 4B, 5A - 5B, among others. Post-processing and testing (610) can entail building the additional structure and / or additional subassembly to then perform the testing of the fabricated device or component or the system-level testing and validation. Notably, the holographic metasurface lithography and curing / fabrication operation can substantially improve the fabrication speed of a device. Time-consuming chemical processing tasks, e.g., metal deposition, etching, photoresist coating, and dielectric deposition that are performed on a layer and layer process can be removed and replaced a single structure formation step 608, e.g.. for a 3D volume having thickness commensurate to multiple layers, and performed in the same lithographic operation.

[0226] Example Alignment System

[0227] Figs. 6B and 6C show an example alignment system for the exemplary system to print the multi-spectral holograms to each other onto the resin with precise alignment. In some embodiments, the metamasks (e.g., 112a, 112b) are each fabricated on a single transparent substrate to be spatially phase aligned to one another.

[0228] Fig. 6B shows an exemplary’ alignment system. The laser incident angles are precisely controlled by alignment gratings fabricated as reference grids on the chip alignment plate. A -1storder diffraction angle can be employed as being equal to the incident angle, so the interference pattern can be used to align the laser.

[0229] Fig. 6C shows an example embodiment of the alignment system of Fig. 6B. The alignment system can be used, e.g., for direct printing of interconnects onto the chip. The alignment system operates with a 6-axis stage. A diffraction pattern is formed on the substrateof the metasurface mask. Misalignment of gratings on the build plate and metamask are then used to precisely align the metamask to the build plate.

[0230] Example Fabricated Devices / Demonstrators

[0231] Figs. 7A - 7E each shows examples of fabricated devices and components that can be fabricated using the method and system.

[0232] Redistribution layer (and other circuits or devices) with planar structures. Specifically. Fig. 7A shows a conventional, bulky, layer-by-layer redistribution layer (RDL) that can be fabricated via a single or multiple lithography and curing of the exemplary method and system. As discussed in relation to Fig. 6A, the fabrication can be performed substantially faster than conventional BEOL processes.

[0233] Redistribution layer (and other circuits or devices) with freeform non-planar structures. Fig. 7B shows space-saving, freeform interconnects that can be fabricated using the exemplary method and system. The freeform interconnect demonstrates the increased design flexibility of the exemplary7system and method in enabling non-planar designs as well as the structures.

[0234] In some embodiments, the interconnect (e.g., redistribution layer device) can be formed using the exemplary system and method. The interconnect can include a plurality of metal wires having a freeform 3D shape. In some embodiments, the plurality7of metal wires comprises a freeform curve wire. The plurality of metal wires can form vias to form electrical connections across multiple layers in the interconnect or electrical device. The plurality7of metal wires can form vias to form electrical connections across multiple layers in the interconnect or electrical device. The plurality7of metal wires form interconnects to form electrical connections across pins of the interconnect or electrical device.

[0235] In some embodiments, an electrical device (e.g.. passive component or active device, e.g., antenna module, antenna-in-package module, microprocessor, microcontroller, ASIC, Al chip) can be formed using the exemplary system and method.

[0236] In some embodiments, the device can include a metallic structure comprising an interconnect structure (e g., redistribution layer, e.g., standard redistribution layer or freeform redistribution layer, e.g.. for multiple stacked IC chips, chiplets. active or passive components, etc., or for multiple IC chips, chiplets, active or passive components, combined in multiple orientations).

[0237] In some embodiments, the device can include a metallic structure comprising an interconnect structure, a routing structure (layout, vias), a portion of a ground plane, a portionof a passive electric component (capacitor, inductor), functionalized electric component (e.g., waveguide, antenna), thermal regulation component, or a combination of both.

[0238] In some embodiments, the polymer structure is a dielectric that forms an interconnect supporting structure.

[0239] In some embodiments, the polymer structure is a dielectric that supports the metallic structure.

[0240] Monolithic Microwave Integrated Circuit. Fig. 7C shows a microsystem demonstrator comprising a digital, mixed-signal, and high-frequency RF prototype. The exemplary HMNL process can provide key tool capability to quickly demonstrate complex back-end-of-the-line (BEOL) connectivity. The direct, fast formation of true 3D structures with metals and dielectrics at sub-micron scales can enable applications with fast reconfigurability of high-frequency tile arrays, where the active Monolithic Microwave Integrated Circuit (MMICs) are designed for wide bandwidth performance and then reconfigured for a specific bandwidth using the HMNL process to create the required passive components (load matching, couplers, power combiners / splitters, filters, etc.).

[0241] In Fig. 7C. a reconfigurable tile array 708 with passive components (dielectric 710, broadside coupler 712, stacked inductor 714, MIM capacitor 716, thin film microstrip line 718, interconnects 720, ground plane 722) is shown printed directly onto the MMIC.

[0242] The quick fabrication capability of the exemplary system and method can additionally provide quick simulation and fabrication of the passive components (e.g., for G- Band frequencies) to quickly achieve the desired performance.

[0243] Non-planer Demonstrator. Fig. 7D shows microscale robotic metamaterials comrising MEMS devices assembled into unit cells such that the metamaterials achieve programable stiffnesses and deformations for applications such as shapeshifting wings. In diagram 702, the prototype devices are assembled by hand and wire-bonded together to achieve functionality. The fabrication process was slow and did not allow for the integration of application-specific integrated circuits (ASICs) into the functional structure.

[0244] In diagram 704, the same prototype device can be fabricated using a robotic metamaterial structure printed using the exemplary HMNL process. In diagram 704, the robotic metamaterial structure can be printed as a six-sided cube with freeform interconnects to connect a custom-designed power management and control ASIC.

[0245] Active Package Demonstrator. Fig. 7E shows a a Lightfield Directing Array (LDA) having two-photon printed flexure beams placed on MEMS actuators and connected to a hexagonal mirror to achieve precise light control. The applications of the LDAs can includeand are not limited to ultra-precise beam pointing, extremely fast beam slewing, and optical wavefront control. The inability to make electrical connections to the mirror limits the functionality of the LDA.

[0246] The exemplary HMNL can address these limitations to print the flexures with high-speed and integrated electrical connections. In Fig. 7E, the two-photon printed flexures 708 are replaced by HMNL-fabricated flextures 710. The exemplary HMNL process can fabricate electronic packages, e.g., as a critical mechanical component in the system architecture, for microelectromechanical applications.

[0247] EXPERIMENTAL RESULTS AND ADDITIONAL EXAMPLES

[0248] A study was conducted to develop and evaluate a Holographic Metasurface NanoLithography (HMNL) process that can use sub-wavelength-pattemed metasurface masks (metamasks) to create multi-colored holograms in a photocurable metal-polymer hybrid resin. The exemplary HMNL process can facilitate the fabrication of entire 3D, multi-material (insulators and conductors) nanoscale structures via a simultaneous pattern from a single light exposure. Metasurfaces may be encoded with higher information density than traditional spatial light modulators such as digital micromirror devices, so the use of metasurface optics in HMNL may overcome many of the low-resolution and small-patteming-area challenges presented by conventional holographic 3D printing approaches. The size of the hologram produced may be limited only by the size of the fabricated metasurface, which may be produced at a full wafer scale.

[0249] A prior study fabricated structures with -500 nm resolution over areas greater than 30 mm x 30 mm using metasurface masks [1], The prior study also designed metasurface optics to produce different holographic patterns when exposed to different colors of light [2], which may be used to create multi-material structures [3] and to fabricate features with resolutions as small as 36 nm [4], Fig. 8A shows the results of volumetric patterning from the prior study, which demonstrated a build rate of over 20 mm3 / s. The metasurface optics of the prior study can be used in the HMNL and lithography / fabrication device described herein.

[0250] Fig. 8A shows (a) Schematic of a nanostructured metasurface used to create a high-resolution hologram that can print nm-scale features and mm-scale objects in a single light exposure; (b) Example of multi -material structure using UV and violet light to create hard and soft components, respectively; (c) Preliminary structures created using HMNL with exposure times of <5 seconds, providing build rates >20 mm3 / s.

[0251] The use of metasurface optics in the instant study allowed for precise alignment of overlapping, multicolored holograms since the spatial registration of the holograms to oneanother was encoded into the metamask design, allowing for sub- 100 nm positional error of the multicolored voxels. The alignment of two UV lights Fig. 1A shows the metasurface masks’s top view, whose alignment marks and supports this precise alignment. The precise control over the position of different colored voxels within the patterned structure facilitated the use of orthogonal chemistries to pattern conductors and insulators simultaneously within the same volumetric structure.

[0252] The exemplary HMNL system of the study utilized ultraviolet light (UV) to pattern the silver metal and visible light to pattern the polymer dielectric, which created a hybrid resin chemi stry. The hybrid resin used metal-organic decomposition (MOD) silver precursors, which have inherent UV curability arising from silver’s native sensitivity to UV light. Upon UV absorption, the silver ions heated up and decomposed the silver complexes and formed the metallic silver, while the remaining components may be volatilized or incorporated into the complimentary photopolymer system. These MOD inks were combined with a UV light radical photoinhibitor, which prevented any or substantially prevented polymerization in the UV exposure regions to allow only the silver metal, or mainly silver metal, to form in this region. In the visible light range, the study used a two-step, two-color photopolymerization chemistry to ensure high resolution by allowing polymer curing to occur only in areas of overlap between the two colors [5],

[0253] All the precursor resin materials used are widely commercially available. The main source of material aging is the presence of unreacted monomers, which can be removed through post-process washing and baking steps. Previous tests have demonstrated the stability of similar silver salt-containing resins to be ~1 month at room temperature and over 3 months when refrigerated.

[0254] AMME Printed Fan-Out Module. AMME Fan-Out Module may be printed as a lower cost, more efficient alternative to current fanout modules with the exemplary HMNL process.

[0255] Fig. 8B shows a process to build an AMME Printed Fan-Out Module with Embedded Chiplets and Passives. At steps “1" - “6,” an AMME redistribution layer (RDL) was printed directly on top of the pProc and chiplets that have been die-attached to the substrate. At step “7,” solder bumps were placed on the backside of the AMME RDL. At step “8,” reflow was used to attach to the next level substrate / PCB.

[0256] Figs. 8C and 8D show the complete structure of the AMME Printed Fan-Out Module with Embedded Chiplets and Passives. In this example device, the exemplary HMNL process reduced the number of layers in the package and reduced the fabrication time and cost.The exemplary HMNL process allowed rapid prototyping and testing of the printed module. Additionally, the exemplary HMNL process allowed the memory die and passive chiplets to be printed and embedded directly in the RDL.

[0257] Table 2 shows example targets for the study.Table 2

[0258] Fabrication of freeform wire structure. Fig. 8E shows the results of an experiment to fabricate a freeform wire structure. The freeform wire structure was formed with overlapping holograms in the exemplary’ HMNL process. In Fig. 8E (bottom left), the crosssection of the wires in the 440 nm light propagation direction is shown. Fig. 8E (bottom right), the cross-section of the wires in the 660 nm light propagation direction is shown.

[0259] Process Characterization

[0260] The study performed process characterizations of the exemplary holographic lithography process, including conductivity, surface roughness assessments, curing, and fabrication capabilities. Figs. 9A - 9C show results of process characterization.

[0261] Conductivity arid Surface Roughness. The study measured the conductivity’ and surface roughness of a cured conductor (e.g., silver) and a cured insulator (e.g.. acrylic).

[0262] For the conductor (silver) assessment, the study printed the conductor with UV- cured resistivity of 3.6 x 10'7Q.m on a copper pad, as shown in Fig. 9A, then annealed the conductor for 30 minutes at 180°C. After the 30-minute anneal, the cured conductor’s resistivity' vas 3.8 x 10"8Q.m. Fig. 9A shows an optical micrograph of the cured conductor area’s surface roughness, which fluctuated around 23.2 nm. The contact resistance to the copper pad was also measured, yvhich was 6.09 x 10‘9ohm-m2

[0263] For the insulator (acrylic) assessment, the study printed the insulator on a copper pad to measure its conductivity’ and contact resistance. After a 5 -minute anneal at 300°C, the measurement did not show any conductivity of the insulator. The crosslinked acrylic networkdoes an excellent job trapping the unreacted silver salts and pacifying them, with demonstrated thermal stability at >300°C. Uncured resin can be drained away from the part just like in standard stereolithography processes. A developer can also be used to remove uncured resin from small pores or gaps.

[0264] From the measurements of the conductivity7and surface roughness of the conductor and insulator, the study found that the partial cure of both conductor (e.g.. silver) and insulator (e.g., polymer) at the interface between the two materials may result in good mechanical and thermal robustness and good adhesion to the printed area.

[0265] The measured surface roughness on the printed silver is 23 nm. The measured surface roughness on the acry lic is 34 nm. It is expected that this can be improved using a more uniform intensity profile in the final HMNL tool.

[0266] Experimental Curing Results. The study formed a resin by diluting 10 wt% Ag in terpineol with 1 : 0.5: 3 wt% for CQ: EDMAB: o-Cl-HABI and 15 wt % PEA / TMPTA. The study then put the resin on the glass slides with 100 uni spacers and exposed the resin piece to a 470 nm (100 tnW / cm2) visible laser beam for 2 minutes, as shown in Fig. 9B. The resin was also exposed to a 365 nm (~1 W / cm2) for 4 minutes as shown in Fig. 9B. The study then separated the slides from the resin and measured the conductivity' of different areas on the resin.

[0267] Fig. 9B shows the resultant resin that includes 3 areas: a visible-light-exposed area, a UV-exposed area, and a thermal decomposed area in between. Fig. 9B shows the conductivity measurements of the visible-light-exposed and the UV-exposed areas. The visible-light-exposed area had no conductivity7, while the UV-exposed area had large conductivity7.

[0268] Printing Overhangs. For several designs, the silver interconnects were encased in the polymer dielectric which acts as a support for the overhangs. Overhangs on the polymer structure may not be a problem due to the use of high-viscosity resins with comparable densities pre- and post-cure, providing neutral buoyancy.

[0269] The active package microsystem does have freestanding polymer overhangs with metal traces inside. For this structure, the study conducted angle tests to create design rules and adjust the geometry of the flexures based on these design rules to ensure the manufacturability of these structures. The contrast of the images generated by the metasurface was sufficiently high to create good polymerization in the target image relative to the surrounding regions, as shown in Fig. 9C.

[0270] Efficiency. The metasurface optics are expected to be about 75% efficient, and based on measured absorption of the resin, it is anticipated that at a penetration depth of 3 mm,the UV laser power will only be -33% of the incident power, reducing the average power to -1 W / cm2 which is the minimum for UV curing of the silver. Lateral dimensions are limited only by the write area of the metasurface mask writer. For a 50 mm x 50 mm x 3 mm volume, 60 x 1012 voxels is required. Therefore, each 4096-level grayscale mask must have at least 121,031 x 121,031 pixels, and at 200 nm per pixel, the mask area is 24 mm x 24 mm, so two independent masks can fit within the 50 mm write area of the mask writer.

[0271] Materials Selection - Metals

[0272] The initial material selection of the metallic precursor consisted of a highly purified (99.995%) silver neodecanoate system. This system is highly organic soluble and UV sensitive. Additionally, this system has been shown to decompose to nearly bulk metallic conductivity (over 80% of the conductivity of silver) when utilized in a traditional ink system and due to its commercial relevance, has had a significant amount of study.

[0273] Silver neodecanoate has a tertiary substituted alpha-carbon whereby the silver catalyzes the decomposition of the salt by a simple scission process triggered by the decarboxylation of the alkyl chain by the silver cation. This stabilized carbocation can then dimerize to a medium chain-length alkane that then evaporates or participates in the larger polymeric matrix offered by the curing of the dielectric polymeric matrix.

[0274] While this system was appreciably soluble (~10wt% silver) in the oligomer matrix, the curing intensity required from the UV light source (>2W / cm2) resulted in unwanted side polymerization reactions with the dielectric matrix precursor oligomers.

[0275] Material Selection - Polymers

[0276] Initially, several candidate monomers were selected to investigate the miscibility between the silver salt, which constitutes the silver ink, and the acrylate monomers used for the polymerization of the insulating polymer. This was also to observe differences in the stability of the silver salt during the solvation process. The presence of solvent can lead to pore formation during the polymer structure formation, which, after evaporation, may result in poor mechanical properties. Additionally, the heat generated during the silver reduction process with high-mtensily UV can cause solvent evaporation, adversely affecting resolution and the formation of conductive domains. Therefore, the objective was to minimize the amount of solvent (terpineol) necessary to completely dissolve the silver salt. A simple visual test was conducted to evaluate the miscibility between the monomer and the silver salt to determine the minimum amount of solvent for complete dissolution while maintaining resin stability (Table 3). Through this test, it was confirmed that 2-phenoxy ethyl acrylate (PEA) and isobomyl acrylate (IBOA) exhibited excellent miscibility but displayed relatively poor stability’ of silverions in solution, which resulted in fast reduction under ambient conditions as indicated by a darkening of the solution. In contrast, tripropyleneglycol diacrylate (TPGDA) and trimethylolpropane triacrylate (TMPTA) were added as crosslinkers to improve mechanical properties while maintaining adequate miscibility and providing good stability.Table 3. The minimum amount of terpineol required to dissolve silver salt with acrylate monomers in a weight ratio of 1:4.

[0277] Resin Composition Ratio Optimization

[0278] Numerous photoinitiators, as well as acrylate monomers and oligomers, were employed with the silver neodecanoate salt. An initial approach, as outlined in Table 3, involved creating a library of formulations using various combinations of TPGDA and TMPTA as crosslinkers (FIG. 10A). The monomer weight ratio in the hybrid resin was fixed at 40%, while the types, combinations, and ratios of monomers were varied.

[0279] While not wishing to be bound to any one theory, higher crosslink density could improve the material stiffness and, to a point, material strength. Further, introducing crosslinkers could facilitate polymerization-induced phase separation (PIPS) during the curing process to provide access to potentially conductive channels. However, when using TPGDA or TMPTA alone, the films became excessively brittle. Some solvent (terpineol) was required under all conditions to provide silver salt dissolution.

[0280] As shown in FIG. 10A, the TPGDA: monofunctional acrylate 1: 1 mixture successfully formed silver regions through UV curing. However, crosslinkers with higher density, like TMPTA or pentaerythritol tetraacrylate (PET A), resulted in films cracking during UV curing, which was attributed to the brittleness of the cured films combined with rapid solvent evaporation upon photothermal heating that occurred during silver reduction. Increasing the monofunctional acrylate ratio, such as 1:3. improved film integrity but reduced conductivity. This highlights the trade-off between mechanical properties and electrical conductivity.

[0281] The TPGDA:PEA (1: 1) combination was found to be the most promising, as it showed the lowest resistance and maintained film integrity under high-intensity UV irradiation. Experiments with varying monomer-to-silver ratios revealed that increasing the monomer ratiomade the structure more polymer-dominant, but it also increased susceptibility to thermal deformation, which is a disadvantage. While increasing the monomer ratio is necessary to reduce solvent, attempts to improve thermal resistance using oligomer additives resulted in a trade-off, negatively affecting electrical conductivity. Ultimately, the 30 wt% monomer formulation provided the best balance of electrical conductivity and film shape retention.

[0282] Through SEM-EDS image analysis of the conductive and insulating regions' surfaces, as demonstrated in FIG. 10C, it was observed that the areas exposed to high-intensity UV were dominated by silver particles. In contrast, the regions where only polymerization occurred were primarily composed of organic polymer structures.

[0283] Multimaterial Deposition

[0284] Inverse Design. To develop the masks needed to generate the holograms for the fabrication of the multimaterial structures, initial inverse mask design algorithms were developed and tested. One test geometry that was produced for evaluating the inverse design algorithms was a trefoil knot. In this inverse design algorithm, the initial creation of trefoil knot objectives is expressed as image "slices’ along the z dimension of the geometry. A NOVO- CGH inverse design algorithm was explored and parameters such as phase plate resolution, z- resolution, and loss function were evaluated using simulations with variations in parameters, and observations about parameter effect on quality of results were recorded. Contrast and intensity variance metrics were selected to quantitatively analyze and compare results. Finally, experiments with different trefoil knot objectives were used to explore hologram quality.

[0285] Hologram Experiments. To test the masks generated using the inverse design algorithm, an optical setup comprising a laser illumination source that outputs a collimated beam (wavelength = 405 nm, bandwidth = 5 nm), a CMOS sensor, and an image relay system that can be translated along the optical axis was used to characterize a hologram mask designed to project a 3D trefoil knot in space. A variation of the optical setup that uses an expanded beam from a UV LED (wavelength = 415 nm, bandwidth = 15 nm) in place of the laser beam was also constructed and used for device testing. It was observed that the masks generated the trefoil knot pattern in space, though there was some difference between the simulations and the experimental results.

[0286] In addition, the study implemented the 4F system for evaluating the effect of numerical aperture (NA) on imaging the hologram. The study also successfully used the metamask with the 4F system to cure a 3D polymer in the resin. For this, the study investigated intensity thresholds for effective curing using single and overlapping beams. The study also conducted 405nm laser diode curing tests with silver resin at varying power levels and exposuretimes to see how well the silver could be cured using longer wavelengths of light. This allowed us to investigate the power intensity conditions necessary for curing silver resin, including threshold values and exposure durations in a system similar to what the final holographic projection system will look like.

[0287] Materials. The initial hybrid resin combines a mix of acrylate monomers, radical photoinitiators, and MOD silver inks that incorporate silver / organic acid salts and a solvent matrix that enhances the reduction of silver and its adhesion to the substrate.

[0288] Optimization of Component Ratio of the Metal-Polymer Hybrid Resin Considering the Chemical Compatibility’ and Physical Properties. Initial experiments showed that silver could be selectively plated in areas of high UV flux, even if the UV exposure occurred post-polymerization of the acrylate. The acrylate resin properties could be well controlled by the addition of crosslinking agents.

[0289] Decolorization. Radicals generated by the photoinitiator were found to induce silver reduction even without exposure to 365 nm UV light. This reduction process resulted in a color change progressing from orange to red and finally to black, depending on the extent of silver reduction (FIG. 12). Interestingly, after this initial color transition, subsequent exposure to low-intensity UV light led to the disappearance of the film's color.

[0290] Experimental results confirmed that this bleaching phenomenon was directly associated with the addition of 2-chlorohexaaryl biimidazole (o-Cl-HABI). Bleaching occurred exclusively in formulations containing o-Cl-HABI, and only these formulations resulted in the formation of conductive silver regions. This finding suggests that o-Cl-HABI plays a critical role not only in the bleaching process but also in ensuring the conductivity of the final silver region.

[0291] Additionally, this bleaching effect could be leveraged to maintain the transparency of the resin, a crucial factor for applications such as holographic printing. By ensuring that non-conductive regions remain transparent, the formulation can contribute to enhanced optical clarity, improving the overall performance of holographic structures.

[0292] Radical Generation by Silver Reduction. The study determined that radicals generated during the silver ink reduction process were also capable of initiating polymerization, forming freestanding films from the hybrid resin. Experimental results demonstrated that the composition of the hybrid resin significantly influences the UV intensity required for effective film formation (FIG. 13). Specifically when different radical species were present, high-quality films could be formed at a low UV intensity of 10 mW / cm2. indicating that these radicals facilitated polymerization. In contrast, mixtures containing only monomer, silver salt, andterpineol (solvent) required a significantly higher UV intensity of 200 mW / cm2to achieve qualitatively similar film formation results.

[0293] Additionally, it was observed that the intensity of UV light irradiation influenced the color change that arose from the silver reduction and polymerization processes. This suggests that additives play a crucial role in controlling the energy threshold for both polymerization and silver reduction processes. Overall, these findings highlight the potential for tuning the multi -material resin system by adjusting the types and concentrations of additives, thereby enabling greater control over the material properties and processing conditions.

[0294] Measured Transmittance. To perform holographic pattering, it is critical that the light can penetrate into the resin formulation. Therefore, the transmittance of the light was measured as a function of curing time during the browning and silver curing process of the silver ink resin. These results were then fitted and used to calculate the transmittance and the change of in refractive index.

[0295] According to the blue dots measured, the transmittance T(t) drops rapidly after the exposure. It can be fitted using a double exponential decay model with offset, t is the exposing time in the unit of seconds as follows.T(t)=0.8477*exp(-1.065*t) + 0.1282*exp(-0.06276*t) + 0.02786

[0296] Based on Beer-Lambert law, the imaginary part k of the resin’s refractive index at 320 nm may be calculated during this process as: k(t)=-Xln(T(t)) / (4*Pi*d),

[0297] where X=320 nm is the wavelength and d=37.3 um is the sample thickness. Using these calculations k was measured to be ~ 2.6x10’3, which is quite lossy.

[0298] Hologram Projection Experiments

[0299] FIG. 16A shows a schematic and photograph of the optical setup that was constructed. The laser illumination from a supercontinuum source (SuperK FIU-15, NKT Photonics), connected to a tunable filter (VARIA, NKT Photonics) was expanded and collimated using a number of mirrors and lenses to form a ~3” (75 mm) diameter collimated beam. Any test sample can be placed in the path of this beam to test its optical performance. In this case, the study investigated the performance of the hologram masks that generate the three- dimensional trefoil knot in 3D space. Since the working distance of the hologram mask is small (~ 5 mm), it is difficult to get the CMOS sensor (DMK37BUX290, Imaging Source) in close proximity to the device. Hence, the study employed an image relay system (MAP107575-A, Thorlabs) with a working distance of ~ 65 mm to relay the image planes formed by thehologram onto the sensor. The camera system (sensor + image relay) was mounted onto an axial scan stage (DDS600. Thorlabs) that enabled us to scan along the optical axis and record multiple frames. A custom LabView code was used to control the stage motion and synchronize it to the frames captured by the sensor. The frames can then be processed in MATLAB and stitched to generate the volumetric projection created by the hologram. The evolution of the individual planes can also be studied, and useful metrics such as contrast and comparison with simulation can be investigated.

[0300] FIG. 16B shows the results of testing one of the hologram masks with the setup employing the superK illumination.

[0301] A variation of the optical setup was also created using a UV LED (M415LP1, Thorlabs). As seen in the results above, the pattern produced by the hologram is low contrast, and there is a lot of background noise. While not wishing to be bound by any one theory, this could be due to the laser speckle present in the superK beam. In order to test this, the study built a second setup employing a 415 nm UV LED. The beam from the LED was allowed to expand over a distance of 550 mm and be incident on the hologram mask. The 3D volumetric light field projection was recorded in the same way using the image relay + sensor as described previously. FIG. 16C shows the schematic and photograph of the setup as well as the spectrum of the LED measured using a spectrometer (Jazz, Ocean Optics) at two locations along the optical axis.

[0302] Although the results improved, as seen in FIG. 16D. compared to FIG. 16C (higher contrast in the pattern), the fields further away from the hologram mask show defocusing. While not wishing to be bound to any one theory, this might be due to the low numerical aperture of the image relay sy stem used. Hence, as a next step, a sensor (DMx 72BUC02, Imaging Source) was placed directly behind the mask to record the 3D light field. However, the results looked similar. FIG. 16E shows a schematic and photograph of this setup along with the results of the light field recording.

[0303] To investigate the feasibility of improving contrast and resolution using overlapping beams, an experiment was set up. as shown in FIG. 16F. Using this beam overlap optimization experiment, the study was able to successfully cure resin only in the overlapping beam regions by adjusting intensity and positioning. With power from one beam at 85% nominal (“ 85*P1”), no cure occurred, but when overlapping with an additional second beam, curing occurred.

[0304] To test the effect of NA on the curing, a 4F System was implemented between the mask and the resin / imaging plane for the purposes of imaging the hologram and improving the cure resolution.

[0305] Using this setup a beam profiler was used to image the hologram, showing that the x,y-dimensions scale by the magnification of the 4F system as expected. By moving the beam profiler back and forth (i.e., towards and away from the 4F system), the study determined that the z-dimension scales by the square of the magnification of the 4F system.

[0306] Conclusion

[0307] Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that an order be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to the arrangement of steps or operational flow; plain meaning derived from grammatical organization or punctuation; the number or type of embodiments described in the specification.

[0308] While the methods and systems have been described in connection with certain embodiments and specific examples, it is not intended that the scope be limited to the particular embodiments set forth, as the embodiments herein are intended in all respects to be illustrative rather than restrictive.

[0309] In this specification and in the claims that follow, reference will be made to a number of terms, which shall be defined to have the following meanings:

[0310] As used herein, “comprising” is to be interpreted as specifying the presence of the stated features, integers, steps, or components as referred to, but does not preclude the presence or addition of one or more features, integers, steps, or components, or groups thereof. Moreover, each of the terms “by”, “comprising,” “comprises”, “comprised of,” “including,” “includes,” “included,” “involving,” “involves,” “involved,” and “such as” are used in their open, non-limiting sense and may be used interchangeably. Further, the term “comprising” is intended to include examples and aspects encompassed by the terms “consisting essentially of’ and “consisting of.” Similarly, the term “consisting essentially of’ is intended to include examples encompassed by the term “consisting of.

[0311] As used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, forexample, reference to “a compound’", “a composition”, or “a cancer”, includes, but is not limited to, two or more such compounds, compositions, or cancers, and the like.

[0312] It should be noted that ratios, concentrations, amounts, and other numerical data can be expressed herein in a range format. It can be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as "about’ ’ that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Ranges can be expressed herein as from “about” one particular value, and / or to “about"’ another particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about.” it can be understood that the particular value forms a further aspect. For example, if the value “about 10” is disclosed, then “10” is also disclosed.

[0313] When a range is expressed, a further aspect includes from the one particular value and / or to the other particular value. For example, where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure, e.g. the phrase “x to y” includes the range from ‘x’ to ‘y’ as well as the range greater than ‘x’ and less than ‘y’. The range can also be expressed as an upper limit, e.g. ‘about x, y, z, or less’ and should be interpreted to include the specific ranges of ‘about x’, ‘about y’, and ‘about z" as well as the ranges of Tess than x’. less than y’, and Tess than z". Likewise, the phrase ‘about x, y. z, or greater’ should be interpreted to include the specific ranges of ‘about x’, 'about y’, and ‘about z’ as well as the ranges of ‘greater than x’, greater than y’, and ‘greater than z’. In addition, the phrase “about ‘x’ to ‘y’”, where ‘x’ and ‘y’ are numerical values, includes “about ‘x" to about ‘y”‘.

[0314] It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a numerical range of “about 0.1% to 5%” should be interpreted to include not only the explicitly recited values of about 0. 1% to about 5%, but also include individual values (e.g., about 1%, about 2%, about 3%, and about 4%) and the subranges (e.g., about 0.5% to about 1.1%; about 5% to about 2.4%; about 0.5% to about 3.2%, and about 0.5% to about 4.4%, and other possible sub-ranges) within the indicated range.

[0315] As used herein, the terms “about,” “approximate,” “at or about,” and “substantially” mean that the amount or value in question can be the exact value or a value thatprovides equivalent results or effects as recited in the claims or taught herein. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art such that equivalent results or effects are obtained. In some circumstances, the value that provides equivalent results or effects cannot be reasonably determined. In such cases, it is generally understood, as used herein, that ‘"about” and “at or about” mean the nominal value indicated ±10% variation unless otherwise indicated or inferred. In general, an amount, size, formulation, parameter or other quantity or characteristic is “about,” “approximate,” or “at or about” whether or not expressly stated to be such. It is understood that where “about.” “approximate,” or “at or about” is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise.

[0316] As used herein, the terms “optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0317] The term “compound,” as used herein, is meant to include all stereoisomers, geometric isomers, tautomers, and isotopes of the structures depicted. Compounds herein identified by name or structure as one particular tautomeric form are intended to include other tautomeric forms unless otherwise specified.

[0318] Compounds are described using standard nomenclature. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to w hich this invention belongs.

[0319] Certain materials, compounds, compositions, and components disclosed herein can be obtained commercially or readily synthesized using techniques generally known to those of skill in the art. For example, the starting materials and reagents used in preparing the disclosed compounds and compositions are either available from commercial suppliers, such as Sigma- Aldrich (formally MilliporeSigma, Burlington, MA) or Thermo Fisher Scientific Inc. (Waltham, MA), or are prepared by methods known to those skilled in the art following procedures set forth in references such as Fieser and Fieser's Reagents for Organic Synthesis (John Wiley and Sons, 2007); Organic Reactions (John Wiley and Sons, 2004); March's Advanced Organic Chemistry, (John Wiley and Sons, 8thEdition); and Larock's Comprehensive Organic Transformations (John Wiley and Sons, 3rdedition, 2017).

[0320] All compounds, and salts thereof, can be found together with other substances such as water and solvents (e.g., hydrates and solvates).

[0321] Compounds provided herein also can include tautomeric forms. Tautomeric forms result from the swapping of a single bond with an adjacent double bond together with the concomitant migration of a proton. Tautomeric forms include prototropic tautomers, which are isomeric protonation states having the same empirical formula and total charge. Example prototropic tautomers include ketone - enol pairs, amide - imidic acid pairs, lactam - lactim pairs, enamine - imine pairs, and annular forms where a proton can occupy two or more positions of a heterocyclic system, for example, 1H- and 3H-imidazole, 1H-, 2H- and 4H- 1,2,4- triazole, 1H- and 2H- isoindole, and 1H- and 2H-pyrazole. Tautomeric forms can be in equilibrium or sterically locked into one form by appropriate substitution.

[0322] Compounds provided herein can also include all isotopes of atoms occurring in the intermediates or final compounds. Isotopes include those atoms having the same atomic number but different mass numbers. For example, isotopes of hydrogen include hydrogen, tritium, and deuterium.

[0323] Also provided herein are salts of the compounds described herein. It is understood that the disclosed salts can refer to derivatives of the disclosed compounds wherein the parent compound is modified by converting an existing acid or base moiety to its salt form. Examples of the salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like. The salts of the compounds provided herein include the conventional non-toxic salts of the parent compound formed, for example, from non-toxic inorganic or organic acids. The salts of the compounds provided herein can be synthesized from the parent compound that contains a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or an organic solvent or in a mixture of the two. In various aspects, nonaqueous media like ether, ethyl acetate, alcohols (e.g., methanol, ethanol, isopropanol, or butanol), or acetonitrile (ACN) can be used.

[0324] As used herein, a ‘‘monomer” refers to a molecule capable of reacting together with other monomer molecules to form a larger polymer chain or three-dimensional network via polymerization.

[0325] As used herein, a “prepolymer” refers to a monomer or system or monomers that have been reacted into a composition having an intermediate-molecular mass state and capable of being further polymerized by reactive groups into a fully cured, high-molecular-mass state.Prepolymers as used herein may refer to mixtures of reactive polymers or mixtures of reactive polymers with unreacted monomers.

[0326] As used herein, a “resin’’ refers to mixture of monomers and / or prepolymers or related substances capable of converting into a rigid polymer by the cross-linking of polymer chains (i.e., curing).

[0327] Throughout this application, various publications may have been referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which this invention pertains.[1] M. Meem, S. Baneiji, C. Pies, T. Oberbiermann. A. Majumder, B. Sensale-Rodriguez, and R. Menon, Large- Area. High-Numerical-Aperture Multi-Level Diffractive Lens via Inverse Design, Optica 7, 252 (2020).[2] N. Mohammad, M. Meem, X. Wan, and R. Menon, Full-Color , Large Area ,Transmissive Holograms Enabled by Multi-Level Diffractive Optics, Sci. Rep. 7, 5789 (2017).[3] M. J. Allen, H.-M. Lien, N. Prine, C. Bums. A. K. Rylski. X. Gu. L. M. Cox. F.Mangolini, B. D. Freeman, and Z. A. Page, Multimorphic Materials: Spatially Tailoring Mechanical Properties via Selective Initiation of Interpenetrating Polymer Networks, Adv. Mater. 35, 2210208 (2023).[4] T. L. Andrew, H.-Y. Tsai, and R. Menon, Confining Light to Deep SubwavelengthDimensions to Enable Optical Nanopatteming, Science (80-. ). 324, 917 (2009).[5] E. S. Rosker, M. T. Barako, E. Nguyen, D. Dimarzio, K. Kisslinger, D. W. Duan, R.Sandhu, M. S. Goorsky, and J. Tice, Approaching the Practical Conductivity Limits of Aerosol Jet Printed Silver, ACS Appl. Mater. Interfaces 12, 29684 (2020).[6] V. Hahn, P. Rietz, F. Hermann, P. Muller, C. Bamer-Kowollik, T. Schlbder, W. Wenzel,E. Blasco, and M. Wegener, Light-Sheet 3D Microprinting via Two-Colour Two-Step Absorption, Nat. Photonics 16, 784 (2022).[7] T. F. Scott, B. A. Kowalski, A. C. Sullivan, C. N. Bowman, and R. R. McLeod, Two-Color Single-Photon Photoinitiation and Photoinhibition for Subdiffraction Photolithography, Science (80-. ). 324, 913 (2009).[8] K. S. Mason, S.-Y. Huang, S. K. Emslie, Q. Zhang, S. M. Humphrey, J. L. Sessler, and Z.A. Page, 3D-Printed Porous Supramolecular Sorbents for Cobalt Recycling, J. Am.Chem. Soc. 146, 4078 (2024).[9] L. Shi, B. Li, C. Kim, P. Kellnhofer, and W. Matusik, Towards Real-Time Photorealistic3D Holography with Deep Neural Networks, Nature 591, 234 (2021).

[0010] R. Menon and N. Brimhall, Perspectives on Imaging with Diffractive Flat Optics, ACSPhotonics 10, 1046 (2023).

[0011] G. Pariani, R. Castagna, R. Menon, C. Bertarelli, and A. Bianco, Modeling Absorbance-Modulation Optical Lithography in Photochromic Films, Opt. Lett. 38, 3024 (2013).

[0012] A. Majumder. P. L. Helms. T. L. Andrew, and R. Menon, A Comprehensive SimulationModel of the Performance of Photochromic Films in Absorbance-Modulation-Optical- Lithography, AIP Adv. 6, 35210 (2016).

[0013] D. Lin, T. M. Hayward, W. Jia, A. Majumder, B. Sensale-Rodriguez, and R. Menon,Inverse-Designed Multi-Level Diffractive Doublet for Wide Field-of-View Imaging, ACS Photonics 10, 2661 (2023).

[0014] W. Jia, D. Lin, R. Menon, and B. Sensale-Rodriguez, Machine Learning Enables theDesign of a Bidirectional Focusing Diffractive Lens, Opt. Lett. 48. 2425 (2023).

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[0020] E. E. Moon, L. Chen, P. N. Everett, M. K. Mondol, and H. I. Smith, Interferometric-Spatial -Phase Imaging for Six- Axis Mask Control, J. Vac. Sci. Technol. B Microelectron. Nanom. Struct. 21, 3112 (2003).

[0021] Q. Yang, X. A. Zhang, A. Bagal, W. Guo, and C.-H. Chang. Antireflection Effects atNanostructured Material Interfaces and the Suppression of Thin-Film Interference, Nanotechnology724, 235202 (2013).EMBODIMENTSEmbodiment 1. A method comprising: combining, via a first optics assembly, (i) a first ultraviolet (UV) beam from a first UV source and (ii) a first non-UV beam (having at least one visible light beam) from a first laser, to form a first combined multi-spectral beam having both UV and non-UV spectral components; combining, via a second optics assembly, (i) a second ultraviolet (UV) beam from a second UV source and (ii) a second non-UV beam (having at least one visible light beam) from a second laser, to form a second combined multi-spectral beam having both UV and non-UV spectral components; directing the first combined multi-spectral beam through a first metamask having a first patterned metasurface formed thereon to generate a first multi-spectral hologram beam, wherein the first patterned metasurface has a first pattern for a first workpiece structure in a first material and a second workpiece structure in a second material, wherein the first pattern forms a first hologram; directing the second combined multi-spectral beam through a second metamask having a second patterned metasurface formed thereon to generate a second multi-spectral hologram beam, wherein the second patterned metasurface has a second pattern for the first workpiece structure in the first material and the second workpiece structure in the second material, wherein the second pattern forms a second hologram; and projecting the first multi-spectral hologram beam and the second multi-spectral hologram beam on a metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose the first hologram and the second hologram in a 3D volume in the metal- polymer hybrid resin, wherein the metal-polymer hybrid resin comprises (i) the first material having a metal component and (ii) the second material having a polymer component, and wherein the first material in the exposed 3D volume having been exposed by both the first multi-spectral hologram beam and the second multi-spectral hologram beam (e.g., at the intersection or overlapping portion thereof) is heated to form a metallic structure within the 3D volume, and wherein the second material in the exposed 3D volume having been exposed by both the first multi-spectral hologram beam and the second multi-spectral hologram beam (e.g., at the intersection or overlapping portion thereof) is cured to form a polymer structure within the 3D volume.Embodiment 2. The method of the embodiment 1, wherein the first non-UV beam(having at least one visible light beam) from the first laser is a first visible light, wherein the second non-UV beam (having at least one visible light beam) from the second laser is a second visible light, wherein the first visible light is the same as the second visible light.Embodiment 3. The method of the embodiment 1, wherein the first non-UV beam(having at least one visible light beam) from the first laser is a first visible light, wherein the second non-UV beam (having at least one visible light beam) from the second laser is a second visible light, wherein the first visible light is different from the second visible light.Embodiment 4. The method of any one of embodiments 1-3. wherein the first hologram and the second hologram are simultaneously projected in the 3D volume in the metal-polymer hybrid resin.Embodiment 5. The method of any one of embodiments 1-3, wherein the first hologram and the second hologram are contemporaneously projected (e.g.. subsequent to each other) in the 3D volume in the metal-polymer hybrid resin.Embodiment 6. The method of any one of embodiments 1-5, wherein the first material and the second material provide insulating and conducting structures in the 3D volume.Embodiment 7. The method of any one of embodiments 1-6 further comprising: projecting the first multi-spectral hologram beam and the second multi-spectral hologram beam at a second location of the metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose a third hologram and a fourth hologram in a second 3D volume in the metal-polymer hybrid resin.Embodiment s. The method of any one of embodiments 1-7, wherein the second material is cured to form the polymer structure within the 3D volume at a first rate, and wherein the first material is heated at a second rate to form the metallic structure within the cured polymer structure within the 3D volume, wherein the first rate is faster than the second rate.Embodiment 9. The method of any one of embodiments 1-8. wherein the metallic structure comprises an interconnect structure (e.g., redistribution layer, e.g., standardredistribution layer or freeform redistribution layer, e.g., for multiple stacked IC chips, chiplets, active or passive components, etc., or for multiple IC chips, chiplets, active or passive components, combined in multiple orientations).Embodiment 10. The method of any one of embodiments 1-8, wherein the metallic structure comprises an interconnect structure, a routing structure (layout, vias), a portion of a ground plane, a portion of a passive electric component (capacitor, inductor), functionalized electric component (e.g., waveguide, antenna), thermal regulation component, or a combination of both.Embodiment 11. The method of any one of embodiments 1-10, wherein the polymer structure is a dielectric that forms an interconnect supporting structure.Embodiment 12. The method of any one of embodiments 1-11, wherein the polymer structure is a dielectric that supports the metallic structure.Embodiment 13. The method of any one of embodiments 1-12, wherein the metal - polymer hybrid resin comprises (i) a polymer, (ii) a metal compound (e.g., metal-organic decomposition (MOD) silver ink or precursor, e.g., upon UV absorption the silver ions heat up, leading to decomposition of the silver complexes and formation of metallic silver), (iii) a visible light photoinitiator (e.g., visible light radical photoinitiator), and (iv) a UV light photoinhibitor (e.g., UV light radical photoinhibitor) (e.g., to prevent polymerization in the UV exposure regions, to allow only the silver metal to form in this region).Embodiment 14. The method of any one of embodiments 1-13, wherein the UV light photoinhibitor comprises bis[2-(o-chlorophenyl)-4,5-diphenylimidazole] (o-Cl-HABI).Embodiment 15. The method of any one of embodiments 1-14, wherein a region of intersection or overlapping portion of the first multi-spectral hologram beam and the second multi-spectral hologram beam provides exposure at sub-500nm resolution (e.g., less than 500 nm, less than 100 nm, less than 10 nm).Embodiment 16. The method of any one of embodiments 1-15, wherein a region of intersection or overlapping portion of the first multi-spectral hologram beam and the second multi-spectral hologram beam provides exposure at micrometer resolution.Embodiment 17. A method comprising: directing a first beam having a UV component through a first metamask having a first patterned metasurface formed thereon to generate a first hologram beam, wherein the first patterned metasurface has a first pattern for a first workpiece structure in a first material, wherein the first pattern forms a first hologram having 3D pattern for the first workpiece structure: directing a second beam having a visible light component through a second metamask (e.g., same metamask at different regions or different metamasks) having a second patterned metasurface formed thereon to generate a second hologram beam, wherein the second patterned metasurface has a second pattern for a second workpiece structure in a second material, wherein the second pattern forms a second hologram having 3D pattern for the second workpiece structure, wherein the first workpiece structure and the second workpiece structure form an integrated component in a same 3D volume: projecting the first hologram beam and the second hologram beam on a metal- polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose the first hologram and the second hologram in the same 3D volume in the metal-polymer hybrid resin, wherein the metal-polymer hybrid resin comprises (i) the first material having a metal component and (ii) the second material having a polymer component, wherein the first material in the exposed 3D volume having been exposed by the first hologram beam is heated to form a metallic structure within the 3D volume, and wherein the second material in the exposed 3D volume having been exposed by the second multi-spectral hologram beam is cured to form a polymer structure within the 3D volume.Embodiment 18. The method of the embodiment 17. wherein the first hologram and the second hologram are simultaneously projected in the 3D volume in the metal-polymer hybrid resin.Embodiment 19. The method of the embodiment 17, wherein the first hologram and the second hologram are contemporaneously projected (e.g., subsequent to each other) in the 3D volume in the metal-polymer hybrid resin.Embodiment 20. The method of any one of embodiments 17-19, wherein the first material and the second material provide insulating and conducting structures in the 3D volume.Embodiment 21. The method of any one of embodiments 17-20 further comprising: projecting the first hologram beam and the second hologram beam at a second location of the metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose a third hologram and a fourth hologram in a second 3D volume in the metal-polymer hybrid resin.Embodiment 22. The method of any one of embodiments 17-21, wherein the second material is cured to form the polymer structure within the 3D volume at a first rate, and wherein the first material is heated at a second rate to form the metallic structure within the cured polymer structure within the 3D volume, wherein the first rate is faster than the second rate.Embodiment 23. The method of any one of embodiments 17-22, wherein the metallic structure comprises an interconnect structure (e.g., redistribution layer, e.g., standard redistribution layer or freeform redistribution layer, e.g., for multiple stacked IC chips, chiplets, active or passive components, etc., or for multiple IC chips, chiplets, active or passive components, combined in multiple orientations).Embodiment 24. The method of any one of embodiments 17-22, wherein the metallic structure comprises an interconnect structure, a routing structure (layout, vias), a portion of a ground plane, a portion of a passive electric component (capacitor, inductor), functionalized electric component (e.g., waveguide, antenna), thermal regulation component, or a combination of both.Embodiment 25. The method of any one of embodiments 17-24, wherein the polymer structure is a dielectric that forms an interconnect supporting structure.Embodiment 26. The method of any one of embodiments 17-25, wherein the polymer structure is a dielectric that supports the metallic structure.Embodiment 27. The method of any one of embodiments 17-26, wherein the hybrid resin comprises (i) a polymer, (ii) a silver ink (e.g., metal-organic decomposition (MOD) silver precursor, e.g., upon UV absorption the silver ions heat up, leading to decomposition of the silver complexes and formation of metallic silver), (iii) a visible light radical photoinitiator, and (iv) a UV light radical photoinhibitor (e.g., to prevent polymerization in the UV exposure regions, to allow only the silver metal to form in this region).Embodiment 28. The method of any one of embodiments 17-27, wherein the UV light radical photoinhibitor comprises bis[2-(o-chlorophenyl)-4,5-diphenylimidazole] (o-Cl-HABI).Embodiment 29. A system configured to perform any one of the methods of embodiments 1-28Embodiment 30. A system comprising: at least one UV laser, including a first UV laser and a second UV laser; at least one visible light laser, including a first visible light laser and a second visible light laser; a metasurface mask having at least one patterned metasurface formed thereon, including a first patterned metasurface, wherein the first patterned metasurface has a first pattern for a first workpiece structure in a first material, wherein the first pattern forms a first hologram; a first optical assembly configured to: combine (i) a first UV beam from the first UV laser and (i) a first visible light beam from the first visible light laser, to form a first combined multi-spectral beam having both UV and visible light components, direct the first combined multi-spectral beam through a metasurface mask to generate a first multi-spectral hologram beam, wherein the first patterned metasurface has a first pattern to form, as a first hologram, both (i) a first workpiece structure in a first material and a second workpiece structure in a second material in a same 3D volume, and direct the first multi-spectral hologram beam on a metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose the first hologram in the 3D volume in the metal-polymer hybrid resin, wherein themetal-polymer hybrid resin comprises (i) the first material having a metal component and (ii) the second material having a polymer component, a second optical assembly configured to: combine (i) a second UV beam from the second UV laser and (i) a second visible light beam from the second visible light laser, to form a second combined multi-spectral beam having both UV and visible light components, direct the second combined multi-spectral beam through the metasurface mask, or a second metasurface mask, to generate a second multi-spectral hologram beam, wherein the metasurface mask or the second patterned metasurface has a second pattern to form, as a second hologram, both (i) the first workpiece structure in the first material and the second workpiece structure in the second material, and direct the second multi-spectral hologram beam on the metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose the second hologram in the 3D volume in the metal-polymer hybrid resin, wherein the first material in the exposed 3D volume having been exposed by the first multi-spectral hologram beam and second multi-spectral hologram beam is heated to form a metallic structure within the 3D volume, and wherein the second material in the exposed 3D volume having been exposed by the first multi-spectral hologram beam and the second multi- spectral hologram beam is cured to form a polymer structure within the 3D volume.Embodiment 31. The system of the embodiment 30 further comprising: a third UV laser; a third visible light laser; a third optical assembly configured to: combine (i) a third UV beam from the third UV laser and (i) a third visible light beam from the third visible light laser, to form a third combined multi-spectral beam having both UV and visible light components, direct the third combined multi-spectral beam through the metasurface mask, or a third metasurface mask, to generate a third multi-spectral hologram beam, wherein the metasurface mask or the third metasurface mask has a third pattern to form, as a third hologram, both (i) the first workpiece structure in the first material and the second workpiece structure in the second material, anddirect the third multi-spectral hologram beam on the metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose the third hologram in the 3D volume in the metal-polymer hybrid resin, wherein the first material in the exposed 3D volume having been exposed by the first multi-spectral hologram beam, the second multi-spectral hologram beam, and the third multi- spectral hologram is heated to form the metallic structure within the 3D volume, and wherein the second material in the exposed 3D volume having been exposed by the first multi-spectral hologram beam, the second multi-spectral beam, and the third multi-spectral hologram beam is cured to form the polymer structure within the 3D volume.Embodiment 32. A system comprising: at least one UV laser, including a first UV laser; at least one visible light laser, including a first visible light laser; a metasurface mask having at least one patterned metasurface formed thereon, including a first patterned metasurface, wherein the first patterned metasurface has a first pattern for a first workpiece structure in a first material, wherein the first pattern forms a first hologram; a first optical assembly configured to: combine (i) a first UV beam from the first UV laser and (i) a first visible light beam from the first visible light laser, to form a first combined multi-spectral beam having both UV and visible light components, direct the first combined multi-spectral beam through a metasurface mask to generate a first multi-spectral hologram beam, wherein the first patterned metasurface has a first pattern to form, as a first hologram, both (i) a first workpiece structure in a first material and a second workpiece structure in a second material in a same 3D volume, and direct the first multi-spectral hologram beam on a metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose the first hologram in the 3D volume in the metal-polymer hybrid resin, wherein the metal-polymer hybrid resin comprises (i) the first material having a metal component and (ii) the second material having a polymer component, wherein the first material in the exposed 3D volume having been exposed by the first multi-spectral hologram beam is heated to form a metallic structure within the 3D volume, and wherein the second material in the exposed 3D volume having beenexposed by the first multi-spectral hologram beam is cured to form a poly mer structure within the 3D volume.Embodiment 33. A system comprising: at least one UV laser, including a first UV laser; at least one visible light laser, including a first visible light laser; at least one metasurface mask, including a metasurface mask having at least one patterned metasurface formed thereon, including a first patterned metasurface, wherein the first patterned metasurface has a first pattern for a first workpiece structure in a first material, wherein the first pattern forms a first hologram; a first optical assembly configured to: direct a first UV beam from the first UV laser through a metasurface mask to generate a first hologram beam, wherein the first patterned metasurface has a first pattern to form, as a first hologram, a first workpiece structure in a first material; direct a first visible light beam from the first visible light laser through the metasurface mask, or a second metasurface mask, to generate a second hologram beam, wherein the metasurface mask, or the second metasurface mask, has a second pattern to form, as a second hologram, a second workpiece structure in a second material; direct the first hologram beam on a metal-polymer hybrid resin, to expose the first hologram in the 3D volume in the metal-polymer hybrid resin, wherein the metal- polymer hybrid resin comprises (i) the first material having a metal component and (ii) the second material having a polymer component, wherein the first material in the exposed 3D volume having been exposed by the first hologram beam is heated to form a metallic structure within the 3D volume, and direct the second hologram beam on the metal-polymer hybrid resin, to expose the second hologram in the 3D volume in the metal-polymer hybrid resin, and wherein the second material in the exposed 3D volume having been exposed by the second multi-spectral hologram beam is cured to form a polymer structure within the 3D volume.Embodiment 34. The system of any one of embodiments 31 - 32, further comprising a second UV laser and / or a second visible light laser.Embodiment 35. The system of any one of embodiments 30 - 34, further comprising the second metasurface mask.Embodiment 36. The system of any one of embodiments 30 - 35, further comprising: a controller configured to direct simultaneous projection of the first hologram and the second hologram in the 3D volume in the metal-polymer hybrid resin.Embodiment 37. The system of any one of embodiments 30 - 35, further comprising: a controller configured to direct contemporaneous projection of the first hologram and the second hologram in the 3D volume in the metal-polymer hybrid resin.Embodiment 38. The system of any one of embodiments 36 - 37, wherein the controller is configured to direct projection of the first multi-spectral hologram beam and the second multi-spectral hologram beam at a second location of the metal-polymer hybrid resin (e.g., photocurable metal-polymer hybrid resin), to expose a third hologram and a fourth hologram in a second 3D volume in the metal-polymer hybrid resin.Embodiment 39. The system of any one of embodiments 30 - 38, wherein the first material and the second material provide an integrated insulating and conducting structure having both an insulating structure and a conducting structure in the 3D volume.Embodiment 40. The system of any one of embodiments 30 - 39, wherein the second material is cured to form the polymer structure within the 3D volume at a first rate, and wherein the first material is heated at a second rate to form the metallic structure within the cured polymer structure within the 3D volume, wherein the first rate is faster than the second rate.Embodiment 41. The system of any one of embodiments 30 - 40, wherein the metallic structure comprises an interconnect structure (e.g., redistribution layer, e.g., standard redistribution layer or freeform redistribution layer, e.g., for multiple stacked IC chips, chiplets, active or passive components, etc., or for multiple IC chips, chiplets, active or passive components, combined in multiple orientations).Embodiment 42. The system of any one of embodiments 30 - 41, wherein the metallic structure comprises an interconnect structure, a routing structure (layout, vias), a portion of aground plane, a portion of a passive electric component (capacitor, inductor), functionalized electric component (e.g.. waveguide, antenna), thermal regulation component, or a combination of both.Embodiment 43. The system of any one of embodiments 30 - 42, wherein the polymer structure is a dielectric that forms an interconnect supporting structure.Embodiment 44. The system of any one of embodiments 30 - 42, wherein the polymer structure is a dielectric that supports the metallic structure.Embodiment 45. The system of any one of embodiments 30 - 44, wherein the metal- polymer hybrid resin comprises (i) a polymer, (ii) a silver ink (e.g., metal-organic decomposition (MOD) silver precursor, e.g., upon UV absorption, the silver ions heat up, leading to decomposition of the silver complexes and formation of metallic silver), (iii) a visible light radical photoinitiator, and (iv) a UV light radical photoinhibitor (e.g., to prevent polymerization in the UV exposure regions, to allow only the silver metal to form in this region).Embodiment 46. The system of any one of embodiments 30 - 45, wherein the UV light radical photoinhibitor comprises bis[2-(o-chlorophenyl)-4,5-diphenylimidazole] (o-Cl-HABI).Embodiment 47. The system of any one of embodiments 30 - 46, wherein the first optical assembly and the second optical assembly collectively provide exposure at sub-500nm resolution (e.g., less than 500 nm, less than 100 nm, less than 10 nm) a region of the intersection or overlapping portion of the first multi-spectral hologram beam and the second multi-spectral hologram beam.Embodiment 48. The system of any one of embodiments 30 - 46, wherein the first optical assembly and the second optical assembly collectively provide exposure at micrometer resolution.Embodiment 49. An interconnect (e.g.. redistribution layer device) comprising: an insulating structure; anda plurality of metal wires formed by any one of the methods of embodiments 1 - 29 or any one of the systems of embodiments 30 - 48.Embodiment 50. An electrical device (e.g., passive component or active device, e.g., antenna module, antenna-in-package module, microprocessor, microcontroller, ASIC, Al chip) comprising: an insulating structure; and a plurality of metal wires (e g., microstrip, vias, interconnect) formed by any one of the methods of embodiments 1-29 or any one of the systems of embodiments 30 - 48.Embodiment 51. The interconnect or electrical device of embodiment 49 or 50, wherein the plurality of metal wires has a freeform 3D shape.Embodiment 52. The interconnect or electrical device of embodiment 49 or 50, wherein the plurality of metal wires comprises a freeform curve wire.Embodiment 53. The interconnect or electrical device of any one of embodiments 49 - 52, wherein the plurality of metal wires form vias to form electrical connections across multiple layers in the interconnect or electrical device.Embodiment 54. The interconnect or electrical device of any one of embodiments 49 - 52, wherein the plurality of metal wires form interconnect to form electrical connections across pins of the interconnect or electrical device.Embodiment 55. A hybrid resin composition comprising: a resin comprising one or more monomers or prepolymers and optionally one or more crosslinkers; thermally decomposable metal precursor; and a photosystem comprising one or more photoinitiators.Embodiment 56. The hybrid resin composition of embodiment 55, wherein the resin comprises one or more acrylate monomers or prepolymers, one or more epoxy monomers or prepolymers, one or more silicon monomers or prepolymers, or combinations thereof.Embodiment 57. The hybrid resin composition of embodiment 55 or 56, wherein the resin comprises one or more acrylate monomers.Embodiment 58. The hybrid resin composition of any one of embodiments 55 - 57, wherein the resin includes one or more monomers and / or one or more crosslinkers selected from 2-phenoxy ethyl acrylate (PEA), isobomyl acrylate (IBOA), tripropyleneglycol diacrylate (TPGDA), trimethylolpropane triacrylate (TMPTA), or combinations thereof.Embodiment 59. The hybrid resin composition of any one of embodiments 55 - 58, wherein the resin includes TPGDA and PEA.Embodiment 60. The hybrid resin composition of embodiment 59, wherein the resin includes TPGDA and PEA, wherein a ratio of TPGDA and PEA is from 3: 1 to 1 :3, more particularly 1 : 1.Embodiment 61. The hybrid resin composition of any one of embodiments 55 - 60, wherein the one or more monomers or prepolymers and optionally one or more crosslinkers are present in the hybrid resin composition at a concentration from 20 wt % to 60 wt % based on a total weight of the hybrid resin composition.Embodiment 62. The hybrid resin composition of any one of embodiments 55 - 61, wherein the thermally decomposable metal precursor comprises ametal salt or a metal particle.Embodiment 63. The hybrid resin composition of any one of embodiments 55 - 62, wherein the thermally decomposable metal precursor comprises a silver salt, a gold salt, a copper salt, a nickel salt, or combinations thereof.Embodiment 64. The hybrid resin composition of any one of embodiments 55 - 63, wherein the thermally decomposable metal salt comprises silver salt (e.g., (including exemplary examples of silver nitrate, silver acetate, silver citrate, silver oxalate, and / or silver chloride) or silver particles.Embodiment 65. The hybrid resin composition of any one of embodiments 55 - 64, wherein the thermally decomposable metal precursor includes a silver carboxylate salt, such as a alpha-substituted silver carboxylate salt, for example silver neodecanoate.Embodiment 66. The hybrid resin composition of any one of embodiments 55 - 64, wherein the thermally decomposable metal precursor is present in the hybrid resin composition at a concentration from 10 wt % to 20 wt % based on a total weight of the hybrid resin composition.Embodiment 67. The hybrid resin composition of any one of embodiments 55 - 66. wherein the one or more photoinitiators are capable of initiating polymerization of the resin upon exposure to a first w avelength of light.Embodiment 68. The hybrid resin composition of the embodiment 67. wherein the one or more photoinitiators are selected from benzoin ethers, benzil ketals, a-dialkoxy- acetophenones, a-hydroxy-alkylphenones, a-amino-alkylphenones. acyl phosphine oxides, benzophenones / amines, thioxanthones / amines, titanocenes, or combinations thereof.Embodiment 69. The hybrid resin composition of the embodiment 67. wherein the one or more photoinitiators are selected from 1-hydroxy-cyclohexyl-phenyl-ketone, a bisacylphosphine oxide (e.g., phenylbis(2,4,6-trimethylbenzoyl) phosphine oxide), camphorquinone / amine (e.g., camphor-quinone and ethyl 4-dimethylaminobenzoate), or combinations thereof.Embodiment 70. The hybrid resin composition of any one of embodiments 67 - 69, further comprising one or more photoinhibitors, wherein the one or more photoinhibitors are capable of quenching the one or more photoinitiators under a second wavelength of light, wherein the second wavelength of light is different from the first wavelength of light, and wherein thermal decomposition of the thermally decomposable metal precursor is capable of occurring upon exposure to the second wav elength of light.Embodiment 71. The hybrid resin composition of the embodiment 70. wherein the one or more photoinhibitors comprises a hexaaryl biimidazole (e.g., bis[2-(o-chlorophenyl)-4,5- diphenylimidazole], i.e., o-Cl-HABI).Embodiment 72. The hybrid resin composition of any one of embodiments 55 - 66, wherein the one or more photoinitiators are capable of initiating polymerization of the resinonly upon exposure to a first wavelength of light and a second wavelength of light, wherein the first wavelength of light and the second wavelength of light are different.Embodiment 67. The hybrid resin composition of the embodiment 66, wherein the one or more photoinitiators comprises 2,3-butanedione.

Claims

WHAT IS CLAIMED IS:

1. A method comprising: combining, via a first optics assembly, (i) a first ultraviolet (UV) beam from a first UV source and (ii) a first non-UV beam (having at least one visible light beam) from a first laser, to form a first combined multi-spectral beam having both UV and non-UV spectral components; combining, via a second optics assembly, (i) a second ultraviolet (UV) beam from a second UV source and (ii) a second non-UV beam from a second laser, to form a second combined multi-spectral beam having both UV and non-UV spectral components; directing the first combined multi-spectral beam through a first metamask having a first patterned metasurface formed thereon to generate a first multi-spectral hologram beam, wherein the first patterned metasurface has a first pattern for a first workpiece structure in a first material and a second workpiece structure in a second material, wherein the first pattern forms a first hologram; directing the second combined multi-spectral beam through a second metamask having a second patterned metasurface formed thereon to generate a second multi-spectral hologram beam, wherein the second patterned metasurface has a second pattern for the first workpiece structure in the first material and the second workpiece structure in the second material, wherein the second pattern forms a second hologram; and projecting the first multi-spectral hologram beam and the second multi-spectral hologram beam on a metal-polymer hybrid resin, to expose the first hologram and the second hologram in a 3D volume in the metal-polymer hybrid resin, wherein the metal-polymer hybrid resin comprises (i) the first material having a metal component and (ii) the second material having a polymer component, and wherein the first material in the exposed 3D volume having been exposed by both the first multi-spectral hologram beam and the second multi-spectral hologram beam is heated to form a metallic structure within the 3D volume, and wherein the second material in the exposed 3D volume having been exposed by both the first multi -spectral hologram beam and the second multi-spectral hologram beam is cured to form a polymer structure within the 3D volume.

2. The method of claim 1, wherein the first non-UV beam from the first laser is a first visible light, wherein the second non-UV beam from the second laser is a second visible light, wherein the first visible light is the same as the second visible light.

3. The method of claim 1, wherein the first non-UV beam from the first laser is a first visible light, wherein the second non-UV beam from the second laser is a second visible light, wherein the first visible light is different from the second visible light.

4. The method of any one of claims 1-3, wherein the first hologram and the second hologram are simultaneously projected in the 3D volume in the metal-polymer hybrid resin.

5. The method of any one of claims 1-3, wherein the first hologram and the second hologram are contemporaneously projected in the 3D volume in the metal-polymer hybrid resin.

6. The method of any one of claims 1-5, wherein the first material and the second material provide insulating and conducting structures in the 3D volume.

7. The method of any one of claims 1-6 further comprising: projecting the first multi-spectral hologram beam and the second multi -spectral hologram beam at a second location of the metal-polymer hybrid resin, to expose a third hologram and a fourth hologram in a second 3D volume in the metal-polymer hybrid resin.

8. The method of any one of claims 1-7, wherein the second material is cured to form the polymer structure within the 3D volume at a first rate, and wherein the first material is heated at a second rate to form the metallic structure within the cured polymer structure within the 3D volume, wherein the first rate is faster than the second rate.

9. The method of any one of claims 1-8, wherein the metallic structure comprises an interconnect structure.

10. The method of any one of claims 1-8, wherein the metallic structure comprises an interconnect structure, a routing structure, a portion of a ground plane, a portion of a passive electric component, functionalized electric component, thermal regulation component, or a combination of both.

11. The method of any one of claims 1-10, wherein the polymer structure is a dielectric that forms an interconnect supporting structure.

12. The method of any one of claims 1-11, wherein the polymer structure is a dielectric that supports the metallic structure.

13. The method of any one of claims 1-12, wherein the metal -polymer hybrid resin comprises (i) a polymer, (ii) a metal compound, (iii) a visible light photoinitiator, and (iv) a UV light photoinhibitor.

14. The method of any one of claims 1-13, wherein the UV light photoinhibitor comprises bis[2-(o-chlorophenyl)-4,5-diphenylimidazole] (o-Cl-HABI).

15. The method of any one of claims 1-14, wherein a region of intersection or overlapping portion of the first multi-spectral hologram beam and the second multi-spectral hologram beam provides exposure at sub-500nm resolution.

16. The method of any one of claims 1-15, wherein a region of intersection or overlapping portion of the first multi-spectral hologram beam and the second multi-spectral hologram beam provides exposure at micrometer resolution.

17. A sy stem compri sing : at least one UV laser, including a first UV laser and a second UV laser; at least one visible light laser, including a first visible light laser and a second visible light laser; a metasurface mask having at least one patterned metasurface formed thereon, including a first patterned metasurface, wherein the first patterned metasurface has a first pattern for a first workpiece structure in a first material, wherein the first pattern forms a first hologram; a first optical assembly configured to: combine (i) a first UV beam from the first UV laser and (ii) a first visible light beam from the first visible light laser, to form a first combined multi-spectral beam having both UV and visible light components.direct the first combined multi-spectral beam through a metasurface mask to generate a first multi-spectral hologram beam, wherein the first patterned metasurface has a first pattern to form, as a first hologram, both a first workpiece structure in a first material and a second workpiece structure in a second material in a same 3D volume, and direct the first multi-spectral hologram beam on a metal-polymer hybrid resin, to expose the first hologram in the 3D volume in the metal-polymer hybrid resin, wherein the metal-polymer hybrid resin comprises (i) the first material having a metal component and (ii) the second material having a polymer component, a second optical assembly configured to: combine (i) a second UV beam from the second UV laser and (i) a second visible light beam from the second visible light laser, to form a second combined multi-spectral beam having both UV and visible light components, direct the second combined multi-spectral beam through the metasurface mask, or a second metasurface mask, to generate a second multi-spectral hologram beam, wherein the metasurface mask or the second patterned metasurface has a second pattern to form, as a second hologram, both the first workpiece structure in the first material and the second workpiece structure in the second material, and direct the second multi-spectral hologram beam on the metal-polymer hybrid resin, to expose the second hologram in the 3D volume in the metal-polymer hybrid resin, wherein the first material in the exposed 3D volume having been exposed by the first multi-spectral hologram beam and second multi-spectral hologram beam is heated to form a metallic structure within the 3D volume, and wherein the second material in the exposed 3D volume having been exposed by the first multi-spectral hologram beam and the second multi- spectral hologram beam is cured to form a polymer structure within the 3D volume.

18. An interconnect comprising: an insulating structure; and aplurality of metal wires formed by any one of the methods of claims 1-16 orthe system of claim 17.

19. An electrical device comprising: an insulating structure; and a plurality of metal wires formed by any one of the methods of claims 1 -16 or the system of claim 17.

20. A hybrid resin composition comprising: a resin comprising one or more monomers or prepolymers and optionally one or more crosslinkers; thermally decomposable metal precursor; and a photosystem comprising one or more photoinitiators.

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