Aperture for flat optical device
By setting a hole material layer on the substrate and patterning it, combined with a structural material layer and photoresist, the problem of stray light in optical devices is solved, and the function and efficiency of the optical system are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- APPLIED MATERIALS INC
- Filing Date
- 2020-05-18
- Publication Date
- 2026-05-12
AI Technical Summary
When existing technologies make it difficult to manufacture optical devices on transparent substrates, stray light incident on the optical system can reduce the functionality and efficiency of the optical system, and optical interactions may occur between the optical device and the substrate and adjacent optical devices.
By setting a hole material layer on the substrate surface and patterning it, combined with the use of a structural material layer, hard mold and photoresist, holes and structures are formed around the optical device to avoid the generation of stray light.
It effectively prevents the generation of stray light, improves the function and efficiency of optical devices, and ensures the normal operation of optical systems.
Smart Images
Figure CN114008524B_ABST
Abstract
Description
[0001] background
[0002] field
[0003] Various embodiments of this disclosure generally relate to optical devices. More specifically, the various embodiments described herein provide the manufacture of one or more optical devices having an aperture surrounding each optical device. Background Technology
[0004] Optical systems can be used to manipulate the propagation of light by spatially varying structural parameters (e.g., shape, size, orientation). One example of an optical device is a planar optical device. Planar optical devices in the visible and near-infrared spectra may require transparent substrates with structures such as nanostructures disposed on the substrate. However, as an emerging technology, processing transparent substrates to form optical devices is both complex and challenging. For example, the beam of one of the optical devices in an incident optical system may be larger in diameter than the desired optical device or not perfectly aligned with it. Stray light from an incident beam larger in diameter than the optical device can degrade the functionality and efficiency of the optical system and may interact optically with the substrate and unwanted adjacent optical devices.
[0005] Therefore, there is a need in the art for a method to fabricate one or more optical devices on a substrate having a hole around each optical device. Summary of the Invention
[0006] In one embodiment, a method is provided. The method includes: forming a hole material layer on a surface of a substrate; patterning the hole material layer to form holes over a region of the substrate surface corresponding to one of: a first space defined by adjacent optical devices and a second space defined by one of the adjacent optical devices and the outer periphery of the substrate; forming a structural material layer over the holes and the surface of the substrate; forming a hard mold over the holes and the structural material layer; disposing a patterned photoresist over the hard mold, the patterned photoresist defining exposed portions of the hard mold; removing these exposed portions of the hard mold to expose structural portions of the structural material layer; and removing the structural portions to form a plurality of structures between the holes over the region of the substrate surface.
[0007] In another embodiment, a method is provided. The method includes: forming a structural material layer on a surface of a substrate; forming a hole material layer over the structural material layer; patterning the hole material layer to form holes over a region of the substrate surface corresponding to one of: a first space defined by adjacent optical devices, and a second space defined by one of the adjacent optical devices and the outer periphery of the substrate; forming an organic planarization layer (OPL) over the holes and the structural material layer; disposing a patterned photoresist over the OPL, the patterned photoresist defining exposed OPL portions; removing the exposed OPL portions to expose structural portions of the structural material layer; and removing the structural portions to form a plurality of structures between the holes over the region of the substrate surface.
[0008] In yet another embodiment, a method is provided. The method includes: forming a structural material layer on the surface of a substrate, the structural material layer being disposed between regions of the substrate surface corresponding to one of: a first space defined by adjacent optical devices, and a second space defined by one of the adjacent optical devices and the outer periphery of the substrate; forming a hard mold over the structural material layer; disposing a patterned photoresist over the hard mold, the patterned photoresist defining exposed portions of the hard mold; removing the exposed portions of the hard mold to expose structural portions of the structural material layer; removing the structural portions to form a plurality of structures between the regions of the substrate surface; and forming holes over the regions. Attached Figure Description
[0009] Therefore, in order to understand in detail the above-described features of this disclosure, a more specific description of the disclosure briefly outlined above can be obtained by referring to various embodiments (some of which are shown in the accompanying drawings). However, it should be noted that the drawings only illustrate several typical embodiments of this disclosure and should therefore not be considered as limiting the scope of this disclosure, as this disclosure may acknowledge many other equivalent embodiments.
[0010] Figure 1A This is a top view of a substrate according to one embodiment, the substrate having one or more optical devices formed on the substrate.
[0011] Figure 1B This is a cross-sectional view of an optical device according to one embodiment of an optical apparatus.
[0012] Figure 2 This is a flowchart illustrating the operation of a method for manufacturing an optical device according to one embodiment.
[0013] Figures 3A to 3F This is a schematic cross-sectional view of an optical device according to one embodiment.
[0014] Figure 4 This is a flowchart illustrating the operation of a method for manufacturing an optical device according to one embodiment.
[0015] Figures 5A to 5E This is a schematic cross-sectional view of an optical device according to one embodiment.
[0016] Figure 6 This is a flowchart illustrating the operation of a method for manufacturing an optical device according to one embodiment.
[0017] Figures 7A to 7G This is a schematic cross-sectional view of an optical device according to one embodiment.
[0018] Figures 8A to 8C This is a flowchart illustrating the operation of a method for manufacturing an optical device according to one embodiment.
[0019] Figures 9A to 9M This is a schematic cross-sectional view of an optical device according to one embodiment.
[0020] For ease of understanding, the same reference numerals have been used to denote common elements in the figures where possible. It is contemplated that elements disclosed in one embodiment may be advantageously used in several other embodiments without particular description. Detailed Implementation
[0021] Several embodiments described herein relate to methods for fabricating optical devices such as metasurfaces. The methods described herein enable the fabrication of one or more optical devices on a substrate having apertures surrounding each optical device, the optical devices having multiple structures, such as nanostructures, formed on the substrate. One embodiment of the methods described herein includes: forming an aperture material layer on a surface of the substrate; forming a structural material layer over the apertures and the surface of the substrate; forming a hard mold over the apertures and the structural material layer; forming a patterned photoresist over the hard mold, the patterned photoresist defining exposed portions of the hard mold; removing the exposed hard mold portions to expose structural portions of the structural material layer; and removing the structural portions to form multiple structures between apertures over a region on the substrate surface.
[0022] Figure 1A This is a top view of substrate 101, which has one or more optical devices 102a, 102b formed on the substrate. Figure 1BThis is a cross-sectional view of optical device 102a. Each of optical devices 102a and 102b includes a plurality of structures 104 disposed on substrate 101. In some embodiments that can be combined with other embodiments described herein, optical devices 102a and 102b are metasurfaces having structures 104, which are nanostructures in the form of nanoscale features formed on or integral with the surface 103 of substrate 101 (e.g., directly or indirectly). The nanostructures can be substantially crystalline, single-crystal, polycrystalline, amorphous, or a combination thereof. In one example, each dimension of the nanostructure has a dimension less than about 1000 nm, for example, less than about 500 nm, less than about 200 nm, less than about 100 nm, or even less than about 20 nm. Although Figure 1A and Figure 1B Structure 104 is shown in a lattice arrangement, but other arrangements are also possible. The lattice arrangement is not intended to limit the scope of the disclosure provided herein.
[0023] The substrate 101 may also be selected to transmit an appropriate amount of light of a desired wavelength or wavelength range, such as one or more wavelengths from about 100 to about 300 nanometers. In some embodiments, without limitation, the substrate 101 is configured such that it transmits greater than or equal to about 50%, 60%, 70%, 80%, 90%, 95%, or 99% of the IR to UV region of the spectrum. The substrate 101 can be formed of any suitable material, provided that it can appropriately transmit light of the desired wavelength or wavelength range and serve as a suitable support for an optical device. In some embodiments that can be combined with other embodiments described herein, the material of the substrate 101 has a relatively low refractive index compared to the refractive index of structure 104. Substrate selection may include substrates of any suitable material, including but not limited to amorphous dielectrics, non-amorphous dielectrics, crystalline dielectrics, silicon oxide, polymers, and combinations thereof. In some embodiments that can be combined with other embodiments described herein, the substrate 101 comprises a transparent material. In one embodiment that can be combined with the other various embodiments described herein, substrate 101 is transparent and has an absorption coefficient of less than 0.001. Suitable examples may include oxides, sulfides, phosphides, tellurides, or combinations thereof. In one example, substrate 101 comprises silicon (Si), silicon dioxide (SiO2), sapphire, and a high-index transparent material containing the material.
[0024] Each of one or more optical devices 102a, 102b has one or more structures 104 formed on or integral with the surface 103 of the substrate 101. In one embodiment that can be combined with other embodiments described herein, structures 104 may have the same dimensions, such as height and width. In another embodiment that can be combined with other embodiments described herein, at least one of the structures 104 may have at least one dimension different from the dimensions of the additional structure 104, such as height and width. In one embodiment that can be combined with other embodiments described herein, structures 104 may have the same refractive index. In another embodiment that can be combined with other embodiments described herein, at least one of the structures 104 may have a refractive index different from the refractive index of the additional structure 104.
[0025] In one embodiment that can be combined with the other multiple embodiments described herein, the structural material, namely the material of structure 104, includes a metal-containing dielectric material, which is not limited to materials containing titanium dioxide (TiO2), zinc oxide (ZnO), tin dioxide (SnO2), aluminum-doped zinc oxide (AZO), fluorine-doped tin oxide (FTO), cadmium stannate (CTO), and zinc stannate (SnZnO3). In another embodiment that can be combined with the other multiple embodiments described herein, the structural material includes a non-conductive amorphous material, such as a dielectric material. The dielectric material may include amorphous dielectrics, non-amorphous dielectrics, and crystalline dielectrics. Examples of dielectric materials include, but are not limited to, a-Si-containing materials, such as silicon nitride (Si3N4) and amorphous silicon (a-Si).
[0026] The method described herein for manufacturing one or more optical devices 102a, 102b includes the formation of aperture 105 (e.g., Figures 3B to 3F , Figures 5B to 5E , Figures 7B to 7G ,and Figure 9E , Figure 9H , Figure 9I , Figure 9L ,and Figure 9MAs shown), aperture 105 is adjacent to each of the outer peripheral structures 106 of structure 104. In several embodiments described herein, apertures are disposed over region 108, which corresponds to a space defined by adjacent optical devices 102a, 102b and a space defined by one of optical devices 102a, 102b to the outer periphery of substrate 101. In some embodiments that can be combined with other embodiments described herein, the apertures are opaque, such that one or more wavelengths in the range of about 100 to about 3000 nanometers are not transmitted. The apertures prevent stray light (i.e., light from an incident beam greater than the surface area defined by each of the outer peripheral structures 106 of structure 104) from degrading the functionality and efficiency of optical devices 102a, 102b. The aperture material, i.e., the material of the aperture, includes, but is not limited to, materials containing chromium (Cr), titanium nitride (TiN), a-Si, titanium (Ti), and aluminum (Al).
[0027] Figure 2 It shows the use of manufacturing such as Figures 3A to 3F A flowchart illustrating the operation of method 200 of the optical device 300. At operation 201, as shown... Figure 3A As shown, a hole material layer 302 is formed on the surface 103 of the substrate 101. The hole material layer 302 can be formed on the surface 103 using liquid material casting, spin coating, liquid spraying, dry powder coating, screen printing, blade coating, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma-enhanced CVD, flowable CVD (FCVD), atomic layer deposition (ALD), evaporation, or sputtering.
[0028] At operation 202, such as Figure 3B As shown, the hole material layer 302 is patterned. The patterned hole material layer 302 forms holes 105 on region 108, which corresponds to a space defined by adjacent optical devices 102a, 102b and a space defined by one of the optical devices 102a, 102b and the outer periphery of the substrate 101. The patterned hole material layer 302 may include photolithography or etching processes, such as ion implantation, ion etching, reactive ion etching (RIE), directional RIE, microblasting, water jet cutting, laser etching, and selective wet chemical etching. Photolithography may include the use of alignment marks and / or features on the surface 103 of the substrate 101.
[0029] At operation 203, such as Figure 3CAs shown, a structural material layer 304 is disposed on the surface 103 of the hole 105 and the substrate 101. The structural material layer 304 can be disposed on the hole 105 and the surface 103 using liquid material casting, spin coating, liquid spraying, dry powder coating, screen printing, blade coating, PVD, CVD, PECVD, FCVD, ALD, evaporation, or sputtering processes.
[0030] At operation 204, such as Figure 3D As shown, a hard mold 306 is disposed on the structural material layer 304. The hard mold 306 can be disposed on the structural material layer 304 using liquid casting, spin coating, liquid spraying, dry powder coating, screen printing, blade coating, PVD, CVD, PECVD, FCVD, ALD, evaporation, or sputtering processes. In one embodiment, which can be combined with several other embodiments described herein, the hard mold 306 is an opaque hard mold that is removed after the optical device 300 is formed. In another embodiment, the hard mold 306 is a transparent hard mold. The hard mold 306 includes, but is not limited to, chromium (Cr), silver (Ag), Si3N4, SiO2, TiN, and carbon-containing (C) materials.
[0031] At operation 205, such as Figure 3D As shown, patterned photoresist 308 is disposed on a hard mold 306. The patterned photoresist 308 is formed by disposing the photoresist material on the hard mold 306 and performing a photolithography process. The patterned photoresist 308 defines a hard mold portion 312 (i.e., an opening in the hard mold 306) of the hard mold 306. The hard mold portion 312 corresponds to a structural pattern 310, resulting in the formation of structure 104. The patterned photoresist 308 can be disposed on the hard mold 306 using a spin coating process. The photoresist material 308 may include, but is not limited to, a material comprising a photosensitive polymer.
[0032] At operation 206, such as Figure 3E As shown, the hard mold portion 312 of the hard mold 306 is removed. Removing the hard mold portion 312 exposes the negative structural portion 314 of the structural material layer 304. The negative structural portion 314 corresponds to the structural pattern 310, resulting in the formation of the structure 104. At operation 207, as... Figure 3E As shown, the negative structural portion 314 of the structural material layer 304 is removed to form structure 104. In one embodiment that can be combined with several other embodiments described herein, the etch rate of the hard mold 306 is lower than that of the structural material layer 304. The hard mold portion 312 and the negative structural portion 314 can be removed by ion etching, RIE, or selective wet chemical etching.
[0033] At operation 208, such as Figure 3F As shown, the hard mold 306 and patterned photoresist 308 are removed. Removing the hard mold 306 may include ion etching, RIE, or selective wet chemical etching. Removing the patterned photoresist 308 may include the photolithography or etching processes described herein. Method 200 forms an optical device 300 having holes 105 disposed over regions 108 adjacent to each peripheral structure 106 of structure 104.
[0034] Figure 4 It is shown as follows Figures 5A to 5E The flowchart shows the operation of the method 400 for manufacturing the optical device 500. At operation 401, as... Figure 5A As shown, a structural material layer 304 is disposed on the surface 103 of the substrate 101. One or more processes provided in operation 203 of method 200 can be used to dispose the structural material layer 304 on the surface 103 of the substrate 101. At operation 402, as... Figure 5A As shown, a hole material layer 302 is disposed on top of a structural material layer 304. One or more processes provided in operation 201 of method 200 can be used to dispose the hole material layer 302 on top of the structural material layer 304. At operation 403, as... Figure 5B As shown, the hole material layer 302 is patterned. The patterned hole material layer 302 forms holes 105 on region 108, which corresponds to a space defined by adjacent optical devices 102a, 102b and a space defined by one of the optical devices 102a, 102b and the outer periphery of the substrate 101. The patterned hole material layer 302 may include one or more processes provided in operation 202 of method 200.
[0035] At operation 404, such as Figure 5C As shown, an organic planarization layer (OPL) 502 is disposed on the structural material layer 304 and the aperture 105. OPL 502 may include a photosensitive organic polymer, which includes a photosensitive material that undergoes a chemical change upon exposure to electromagnetic (EM) radiation and is therefore configured to be removed using a developing solvent. For example, the photosensitive organic polymer may be a polyacrylate resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene ether resin, polyphenylene sulfide resin, or benzocyclobutene (BCB). More generally, for example, OPL 502 may include any organic polymer and a photosensitive compound having a molecular structure capable of attaching to the organic polymer. A spin coating process can be used to set OPL 502.
[0036] At operation 405, such as Figure 5C As shown, a patterned photoresist 308 is disposed on an OPL 502. The patterned photoresist 308 is formed by disposing the photoresist material on the OPL 502 and performing a photolithography process. The patterned photoresist 308 defines an OPL portion 504 (i.e., an opening in the OPL 502) of the OPL 502. The OPL portion 504 corresponds to a structural pattern 310, resulting in the formation of a structure 104. The patterned photoresist 308 can be disposed on the OPL 502 using a spin coating process. The patterned photoresist 308 may include, but is not limited to, a material comprising a photopolymer.
[0037] At operation 406, such as Figure 5D As shown, the OPL portion 504 of OPL 502 is removed. Removing the OPL portion 504 exposes the negative structural portion 314 of the structural material layer 304. The negative structural portion 314 corresponds to the structural pattern 310, resulting in the formation of structure 104. The OPL portion 504 can be removed by RIE, wet etching, and photolithography. At operation 407, as... Figure 5D As shown, the negative structural portion 314 of the structural material layer 304 is removed to form structure 104. The negative structural portion 314 can be removed by ion etching, RIE, or selective wet chemical etching.
[0038] At operation 408, such as Figure 5E As shown, OPL 502 and patterned photoresist 308 are removed. Removal of patterned photoresist 308 may include the photolithography or etching processes described herein. Method 200 forms an optical device 500 having holes 105 disposed over regions 108 adjacent to each peripheral structure 106 of structure 104.
[0039] Figure 6 It is shown as follows Figures 7A to 7G The flowchart shown illustrates the operation of the method 600 for manufacturing the optical device 700. At operation 601, as... Figure 7A As shown, a structural material layer 304 is disposed on the surface 103 of the substrate 101. One or more processes provided in operation 203 of method 200 can be used to dispose the structural material layer 304 on the surface 103 of the substrate 101. At operation 602, as... Figure 7A As shown, a hard mold 306 is disposed on the structural material layer 304. One or more processes provided in operation 204 of method 200 can be used to dispose the hard mold 306 on the structural material layer 304.
[0040] At operation 603, such as Figure 7AAs shown, a hole material layer 302 is disposed on the hard mold 306. One or more processes provided in operation 201 of method 200 can be used to dispose the hole material layer 302 on the hard mold 306. In one embodiment that can be combined with several other embodiments described herein, the structural material layer 304 is an a-Si-containing layer having a thickness of about 450 nm to about 1000 nm, the hard mold 306 is a Si3N4-containing layer having a thickness of about 10 nm to about 150 nm, and the hole material layer 302 is a Cr-containing layer having a thickness of about 10 nm to about 200 nm. At operation 604, as... Figure 7B As shown, the hole material layer 302 is patterned. The patterned hole material layer 302 forms holes 105 on region 108, which corresponds to a space defined by adjacent optical devices 102a, 102b and a space defined by one of the optical devices 102a, 102b and the outer periphery of the substrate 101. The patterned hole material layer 302 may include one or more processes provided in operation 202 of method 200.
[0041] At operation 605, such as Figure 7C As shown, OPL 502 is positioned on the hard mold 306 and the hole 105. At operation 606, as... Figure 7C As shown, patterned photoresist 308 is disposed on OPL 502. Patterned photoresist 308 is formed by disposing photoresist material on OPL 502 and performing photolithography. The patterned photoresist 308 defines the OPL portion 504 of OPL 502. The OPL portion 504 corresponds to the structural pattern 310, resulting in the formation of structure 104.
[0042] At operation 607, such as Figure 7D As shown, remove the OPL portion 504 of OPL 502. Removing the OPL portion 504 exposes the hard mold portion 312 of the hard mold 306. At operation 608, as... Figure 7D As shown, the hard mold portion 312 of the hard mold 306 is removed. Removing the hard mold portion 312 exposes the negative structural portion 314 of the structural material layer 304. The negative structural portion 314 corresponds to the structural pattern 310, resulting in the formation of the structure 104. At operation 609, as... Figure 7E As shown, OPL 502 and patterned photoresist 308 are removed. Removal of patterned photoresist 308 may include the photolithography or etching processes described herein.
[0043] At operation 610, such as Figure 7F As shown, the negative structural portion 314 of the structural material layer 304 is removed to form structure 104. At operation 611, as... Figure 7GAs shown, the hard mold 306 is removed. Removing the hard mold 306 may include one or more processes provided in operation 204 of method 200. Method 200 forms an optical device 700 having holes 105 disposed over regions 108 adjacent to each peripheral structure 106 of structure 104.
[0044] Figure 8A It is shown as follows Figures 9A to 9E The flowchart shown illustrates the operation of the method 800A for manufacturing the optical device 900A. At operation 801, as... Figure 9A As shown, a structural material layer 304 is disposed on the surface 103 of the substrate 101. One or more processes provided in operation 203 of method 200 can be used to dispose the structural material layer 304 on the surface 103 of the substrate 101.
[0045] At operation 802, such as Figure 9A As shown, a hard mold 306 is disposed on the structural material layer 304. One or more processes provided in operation 204 of method 200 can be used to dispose the hard mold 306 on the structural material layer 304. At operation 803, as... Figure 9B As shown, patterned photoresist 308 is disposed on a hard mold 306. The patterned photoresist 308 is formed by disposing photoresist material on the hard mold 306 and performing photolithography. The patterned photoresist 308 defines a hard mold portion 312 of the hard mold 306. The hard mold portion 312 corresponds to a structural pattern 310, resulting in the formation of structure 104.
[0046] At operation 804, such as Figure 9C As shown, remove the hard mold portion 312 of hard mold 306. At operation 805, as... Figure 9C As shown, the negative structural portion 314 of the structural material layer 304 is removed to form structure 104. At operation 806, as... Figure 9D As shown, the hard mold 306 and the patterned photoresist 308 are removed.
[0047] At operation 807, a masking substrate 101 is used to expose regions 108 adjacent to each outer peripheral structure 106 of structure 104. The masking substrate 101 may include a shadow mask placed over structure 104 to expose regions 108. At operation 808, as... Figure 9E As shown, holes 105 are disposed on regions 108 adjacent to each of the outer peripheral structures 106 of structure 104.
[0048] Figure 8B It is shown as follows Figures 9A to 9D and Figures 9F to 9IThe flowchart shown illustrates the operation of method 800B for manufacturing optical device 900B. Method 800B includes operations 801-806. At operation 809, as... Figure 9F As shown, gap-filling material 902 is disposed on structure 104. Gap-filling material 902 includes, but is not limited to, materials containing polymers, OPL, and spin-coated materials. At operation 810, as... Figure 9G As shown, a hole material layer 302 is provided over the gap filling material 902 and region 108. One or more processes provided in operation 201 of method 200 can be used to provide the hole material layer 302 over the gap filling material 902 and region 108. At operation 811, as... Figure 9H As shown, the pore material layer 302 above the gap filler material 902 is removed to form a hole 105 above region 108. At operation 812, as... Figure 9I As shown, the gap filler material 902 is removed. The gap filler material 902 can be removed by solvent, wet etching, ashing, and RIE. Methods 800A and 800B form an optical device 900A, 900B having holes 105 disposed on regions 108 adjacent to each outer peripheral structure 106 of structure 104.
[0049] Figure 8C It is shown as follows Figures 9A to 9D and Figure 9J The flowchart of the operation of the method 800C for manufacturing the optical device 900C is shown in Figure 9N. Method 800C includes operations 801-806. At operation 813, as... Figure 9J As shown, an encapsulation layer 904 is disposed on structure 104 and region 108. Encapsulation layer 904 includes, but is not limited to, Si3N4, SiO2, low-refractive-index fluoropolymers, hydrogels, and materials containing photoresist. Encapsulation layer 904 can be disposed by one or more of PVD, CVD, FCVD, and spin coating. At operation 814, as... Figure 9J As shown, a hole material layer 302 is disposed on the encapsulation layer 904. One or more processes provided in operation 201 of method 200 can be used to dispose the hole material layer 302 on the encapsulation layer 904. At operation 815, as... Figure 9K As shown, a patterned etched layer 906 is disposed on the hole material layer 302 corresponding to region 108, and a portion 908 of the hole material layer 302 is exposed on structure 104. At operation 816, as... Figure 9L As shown, a portion 908 of the hole material layer 302 above structure 104 is removed to form a hole 105 above region 108. At operation 817, as... Figure 9MAs shown, the patterned etched layer 906 is removed. Method 800C forms an optical device 900C having holes 105 disposed on regions 108 adjacent to each outer peripheral structure 106 of structure 104.
[0050] In summary, the various embodiments described herein relate to methods for manufacturing optical devices. The methods described herein enable the fabrication of one or more optical devices on a substrate having an aperture surrounding each optical device, the optical device having multiple structures. The aperture is disposed over a region corresponding to a space defined by adjacent optical devices and a space defined by one of the optical devices relative to the outer periphery of the substrate. The aperture is opaque, such that one or more wavelengths are not transmitted. The aperture prevents stray light (i.e., light from an incident beam greater than the surface area defined by each outer periphery of the structure) from degrading the function and efficiency of the optical device.
[0051] Although the foregoing describes several embodiments of this disclosure, other and further embodiments of this disclosure may be devised without departing from the basic scope of this disclosure, and the scope of this disclosure is determined by the scope of the appended claims.
Claims
1. A method for manufacturing a flat optical device, comprising the following steps: A porous material layer is formed on the surface of a transparent substrate; The hole material layer is patterned to form holes over a region of the surface of the transparent substrate corresponding to one of the following: The first space defined by adjacent optical devices; and A second space defined by one of the adjacent optical devices and the outer periphery of the transparent substrate; A structural material layer is disposed above the hole and the surface of the transparent substrate; A hard mold is provided on the hole and the structural material layer; Patterned photoresist is applied onto the hard mold, and the patterned photoresist defines the exposed portion of the hard mold. Remove the exposed hard mold portion to expose the structural portion of the structural material layer; and Multiple structures are formed between the holes on the surface of the transparent substrate by removing portions of the structure to create a super-surface of the planar optical device, wherein the holes are opaque.
2. The method of claim 1, wherein after forming the plurality of structures, the patterned photoresist and the hard mold are removed.
3. The method of claim 2, wherein removing the patterned photoresist comprises at least one of photolithography or etching.
4. The method of claim 1, wherein the porous material layer comprises one or more materials containing chromium (Cr), titanium nitride (TiN), amorphous silicon (a-Si), titanium (Ti), and aluminum (Al).
5. The method of claim 1, wherein the material of the pore prevents light with wavelengths in the range of 100 nanometers to 3000 nanometers from being transmitted through the pore.
6. The method of claim 1, wherein the hard mold comprises one or more materials containing chromium (Cr), silver (Ag), silicon nitride (Si3N4), silicon oxide (SiO2), TiN, and carbon (C).
7. The method of claim 1, wherein setting the hard mold includes one or more of liquid material casting, spin coating, liquid spraying, dry powder coating, screen printing, blade coating, PVD, CVD, PECVD, FCVD, and ALD.
8. The method of claim 1, wherein the hard mold has greater etch selectivity than the structural material layer.
9. The method of claim 1, wherein each of the plurality of structures is a nanostructure having a size of less than 1000 nanometers (nm).
10. A method for manufacturing a flat optical device, comprising the following steps: A structural material layer is formed on the surface of a transparent substrate; A porous material layer is provided on top of the structural material layer; The hole material layer is patterned to form holes over a region of the surface of the transparent substrate corresponding to one of the following: The first space defined by adjacent optical devices; and A second space defined by one of the adjacent optical devices and the outer periphery of the transparent substrate; An organic planarization layer (OPL) is disposed on the holes and the structural material layer. A patterned photoresist is applied over the OPL, the patterned photoresist defining the exposed portion of the OPL; Remove the exposed OPL portion to expose the structural portion of the structural material layer; and Multiple structures are formed between the holes on the surface of the transparent substrate by removing portions of the structure to create a super-surface of the planar optical device, wherein the holes are opaque.
11. The method of claim 10, wherein a hard mold is disposed between the structural material layer and the hole material layer.
12. The method of claim 11, wherein the structural material layer is a layer containing amorphous silicon (a-Si), the hard mold is a layer containing silicon nitride (Si3N4), and the pore material layer is a layer containing chromium (Cr).
13. The method of claim 12, wherein the a-Si-containing layer has a first thickness of 450 nanometers (nm) to 650 nm, the Si3N4-containing layer has a second thickness of 10 nm to 200 nm, and the Cr-containing layer has a third thickness of 10 nm to 200 nm.
14. The method of claim 10, wherein after forming the plurality of structures, the patterned photoresist and the OPL are removed.
15. A method for manufacturing a flat optical device, comprising the following steps: A structural material layer is disposed on the surface of a transparent substrate, the structural material layer being disposed between regions of the surface of the transparent substrate corresponding to one of the following: The first space defined by adjacent optical devices; and A second space defined by one of the adjacent optical devices and the outer periphery of the transparent substrate; A hard mold is disposed on the structural material layer; Patterned photoresist is applied onto the hard mold, and the patterned photoresist defines the exposed portion of the hard mold. Remove the exposed hard mold portion to expose the structural portion of the structural material layer; Multiple structures are formed by removing portions of the structure to create a metasurface of the planar optical device between the regions on the surface of the transparent substrate; and An aperture is formed over the area, wherein the aperture is opaque.
16. The method of claim 15, wherein forming the hole over the region comprises: An encapsulation layer is disposed on the plurality of structures and the region; A hole material layer is disposed on the encapsulation layer; A patterned etched layer is formed over the region to expose portions of the pore material layer over the plurality of structures; Remove the portion of the porous material layer over the plurality of structures; and Remove the patterned etched layer.
17. The method of claim 16, wherein the encapsulation layer comprises one or more materials selected from silicon nitride (Si3N4), silicon oxide (SiO2), fluoropolymer, hydrogel, and photoresist.
18. The method of claim 15, wherein forming the hole over the region comprises: The multiple structures are covered to expose the area.
19. The method of claim 15, wherein forming the hole over the region comprises: A gap-filling material is disposed on the plurality of structures between the regions; A pore material layer is provided on the gap filling material and the region; Remove the pore material layer above the gap-filling material; and Remove the gap-filling material.