Seed structure for structured coatings used in optical devices and other devices

Abstract

This invention relates to a method comprising forming a coating on a surface of a substrate, wherein a plurality of seed structures are arranged on the surface of the substrate, wherein the respective heights of the seed structures define the local thickness of the coating. An optical device includes a substrate, a plurality of seed structures on the surface of the substrate, and a coating on the seed structures and on the surface of the substrate, wherein the respective heights of the seed structures define the local thickness of the coating.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 847,522, filed May 14, 2019, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to seed structures for structured coatings used in optical devices and other devices. Background Technology

[0004] Coatings on a substrate can provide various device functions, including optical functions. For example, coatings with suitable structures can provide diffractive optical effects, including lensing, light diffusion, focusing, and beam shaping. Such structured coatings can include stepped, multi-level coatings, coatings with different thicknesses, and coatings with specific surface profiles. Summary of the Invention

[0005] In one aspect, this disclosure describes a method comprising forming a coating on a surface of a substrate, wherein a plurality of seed structures are arranged on the surface of the substrate, wherein the respective heights of the seed structures define a local thickness of the coating.

[0006] Implementations of this method may include one or more of the following: A localized thickness of the coating defines a diffractive optical element formed by the coating. Multiple seed structures are arranged on a stepped surface under the substrate, wherein exposed surfaces of the coating have profiles corresponding to contours defined by distal surfaces of the seed structures, and wherein the bottom surface of the coating follows the stepped surface under the substrate. Setting the coating involves depositing the coating using surface growth techniques, and the coating is at least partially grown from the surfaces of the multiple seed structures. Atomic layer deposition or chemical vapor deposition is used to deposit the coating.

[0007] Implementations of this method may include one or more of the following: A plurality of seed structures include at least one of pillars or walls. The plurality of seed structures are protrusions from the surface of a substrate, and at least some of the protrusions have a different height than the others. A coating fills the space between adjacent seed structures. The method includes, after applying the coating, removing portions of the coating such that at least a portion of the substrate surface on which the seed structures are not disposed does not have an overlying coating. The substrate is a first substrate, and the method further includes attaching a second substrate to the exposed surface of the coating and removing the first substrate and the seed structures. The method further includes, after removing the first substrate and the seed structures, applying additional coatings such that the voids left by the removed seed structures are filled by the additional coatings. The method includes, prior to applying the coating, imprinting receiving material to form seed structures on the surface of the substrate.

[0008] This disclosure also describes optical devices. In one aspect, this disclosure describes an optical device comprising a substrate, a plurality of seed structures on the surface of the substrate, and coatings on the seed structures and on the surface of the substrate, wherein the respective heights of the seed structures define the local thickness of the coating.

[0009] Embodiments of this optical device may include one or more of the following: The local thickness of the coating defines a diffractive optical element formed by the coating. The diffractive optical element is a lens. Multiple substrate structures are protrusions from the surface of the substrate, and at least some of the protrusions have a different height than the others. The coating fills the space between adjacent substrate structures.

[0010] In one aspect, this disclosure describes an optical device comprising a substrate and a coating on the surface of the substrate, wherein a plurality of voids are formed in the coating, and wherein the coating forms at least one optical element. In some embodiments, the voids protrude from the surface of the coating toward the surface of the substrate, and the portion of the coating in which the voids are formed comprises at least two different thicknesses.

[0011] This disclosure also describes modules. In one aspect, this disclosure describes a module comprising at least one of a light-emitting device or a photosensitive device; and an optical device as described in this disclosure, wherein the optical device is configured to (i) interact with light generated by the light-emitting device or (ii) interact with light incident on the module such that light passing through the optical device is received by the photosensitive device.

[0012] Specific embodiments of the subject matter described in this disclosure may be implemented to achieve one or more advantages. For example, in some embodiments, the manufacturing process may be less complex, time-consuming, and / or expensive. In some embodiments, highly complex and varied structured coatings can be manufactured. In some embodiments, the optical device may be more compact and / or more efficient. In some embodiments, the structured coating may be composed of a material with a higher refractive index.

[0013] Details of one or more embodiments are set forth in the accompanying drawings and the following description. Other aspects, features, and advantages will become apparent from the description, the drawings, and the claims. Attached Figure Description

[0014] Figure 1A-1B This is a schematic diagram illustrating an example of a structured coating manufacturing process and apparatus.

[0015] Figure 2A-2C This is a schematic diagram illustrating an example of a structured coating manufacturing process and apparatus.

[0016] Figures 3A-3E This is a schematic diagram illustrating an example of a structured coating manufacturing process and apparatus.

[0017] Figure 4 These are scanning electron micrographs showing examples of the base structure and structured coating.

[0018] Figure 5 This is a top view schematic diagram showing an example of a seed structure arranged on a substrate.

[0019] Figure 6 This is a schematic diagram showing an example of an optoelectronic module. Detailed Implementation

[0020] This disclosure relates to seed structures for structured substrate coatings. In a particular embodiment, this disclosure describes seed structures disposed on a substrate surface, the respective height of which defines the local thickness of the coating.

[0021] Coatings on a substrate can provide various device functions, including optical functions. For example, coatings with suitable structures can provide diffractive optical effects, including lensing, light diffusion, focusing, and beam shaping. Such structured coatings may include stepped, multi-level coatings, coatings with different thicknesses, and coatings with specific surface profiles.

[0022] However, structured coatings can be difficult or expensive to manufacture. For example, using some known photolithography techniques, producing an eight-level optical structure may require at least three exposures and three etching steps. This can make the manufacturing process both time-consuming and expensive, increasing with each additional level of the optical structure. Other types of coating structures, such as coatings that form domes or pyramids on the substrate surface, may present even greater manufacturing challenges.

[0023] Therefore, in some cases, it may be beneficial to adopt seed structures in manufacturing processes and equipment to reduce manufacturing complexity, time consumption and cost, and / or to produce structured coatings.

[0024] like Figure 1A As shown, some embodiments include a seed structure 104 disposed on the surface 102 of the substrate 100. The seed structure 104 protrudes from the surface 102 of the substrate 100 and may have different heights (e.g., heights 106a and 106b).

[0025] In some embodiments, the seed structure 104 is an extension of the substrate 100, for example, formed of the same material as the substrate 100. In some embodiments, the seed structure 104 is formed of a different material from the substrate 100, for example, deposited on the substrate surface 102 or formed of a film disposed on the substrate surface 102.

[0026] like Figure 1B As shown, coating 108 is disposed on substrate surface 102 and seed structure 104, and fills the region between adjacent seed structures 104. The corresponding height of seed structure 104 defines the local thickness of coating 108, such that coating 108 forms a structure such as pyramid 110 and dome 112. Therefore, coating 108 can be referred to as a structured coating.

[0027] The corresponding height of the seed structure 104 defines the local thickness of the coating; however, in some embodiments, the corresponding height of the seed structure is not necessarily equal to the local thickness of the coating. Instead, in some embodiments, a change in the height of the seed structure corresponds to a change in the local thickness of the coating. In some embodiments, the local thickness of the coating is greater than or less than a defined offset of the seed structure height. In some embodiments, the structure formed by the coating corresponds to the structure of the bottom seed structure.

[0028] In some embodiments, a coating 108 is deposited using a surface growth technique, wherein the coating 108 is grown substantially perpendicularly from a surface (e.g., including a substrate surface 102, a sidewall 114 of a seed structure, and a distal surface 116 of a seed structure) such that the coating 108 forms a conformal cover on the bottom surface.

[0029] When coating 108 is deposited using surface growth techniques or other methods (where the coating is deposited from a bottom surface), the corresponding height of the seed structure 104 can define the local thickness of coating 108 by setting the bottom surface on which the coating can be formed and / or grown. For example, if a coating thickness x is arranged over a portion of the substrate surface 102 that does not have seed structure 104, approximately the same coating thickness x can be arranged over a seed structure having a height h, such that the height of the coating surface on the seed structure is approximately the height x + h on the substrate surface 102. Thus, in some cases, a substrate region with a taller seed structure, defined with reference to the substrate surface 102, will result in a correspondingly larger local thickness of the coating, while a substrate region with a shorter seed structure will result in a correspondingly smaller local thickness of the coating.

[0030] When coating 108 is deposited using surface growth techniques or other methods (where the coating is deposited from a bottom surface), seed structure 104 can fill the space between adjacent seed structures 104 by growing the coating outward from the sidewall 114 of seed structure 104 (e.g., from one seed structure 104 to another). In some embodiments, if coating 108 has a thickness x defined by a reference coating 108 from the surface from which it is grown (e.g., vertically from substrate surface 102, or horizontally, parallel to substrate surface 102, from the sidewall 114 of the seed structure), adjacent seed structures can be spaced apart from each other by a distance less than 2x, such that coating 108 fills the entire space between adjacent seed structures.

[0031] The deposition method used to provide coating 108 may include one or more of atomic layer deposition (ALD), vapor phase deposition (e.g., chemical vapor deposition, plasma-enhanced chemical vapor deposition, or metal-organic vapor deposition), or physical vapor deposition (e.g., thermal evaporation or sputtering). In some embodiments, deposition parameters are selected to promote conformal growth of coating 108. For example, a relatively low deposition vacuum may be used in a sputtering process, making it more likely that coating material will scatter and coat the bottom sidewalls.

[0032] The coating 108 may include, for example, oxides (e.g., one or more of Al2O3, TiO2, SiO2, ITO, HfO, Ta2O5, LiNbO3, or ZrO2).

[0033] The coating 108 may include, for example, a nitride (e.g., one or more of AlN, GaN, and Si3N4).

[0034] Coating 108 may include other materials. For example, coating 108 may include ZnSe or other compounds useful in optical devices. Coating 108 may include organic compounds, such as polymers. Coating 108 may include one or more of metals (e.g., to provide a plasma effect) or dielectrics.

[0035] In some cases, coating 108 can have any thickness between tens of nanometers and hundreds of micrometers. In some embodiments, coating 108 has a thickness between about 20 nm and about 200 nm.

[0036] Without the seed structure 104, the coating 108 can form a relatively featureless film on the substrate surface 102. Alternatively, to fabricate structures 110, 112 using other methods, more complex, lengthy, or expensive manufacturing processes may be required. However, due to the seed structure 104, the coating 108 directly forms structures 110, 112 while providing the coating.

[0037] Although Figure 1A-1B The substrate surface 102 is shown as flat, but in some embodiments, the substrate surface may be patterned (e.g., stepped or roughened) or curved.

[0038] The structures formed by coating 108 (e.g., structures 110 and 112) may include optical elements, such as diffractive optical elements (DOEs). The optical functions of the structures may include, for example, one or more of lensing, reflection or antireflection, beam splitting, focusing, or optical diffusion. The structures may be microlenses, such that multiple structures form a microlens array. The structures may include gratings, such as diffraction gratings. The structures may include and / or form metasurfaces with optical functions.

[0039] The seed structure 104 can be provided in many different shapes, such as columns (square, circular, or rectangular), walls, or ridges, and can be arranged in different lattice patterns or distributed in different geometries, such as forming closed loops or dashed lines. The seed structure 108 can be configured in one or more of periodic, regular, or random geometries.

[0040] Different combinations of the shape of the seed structure 104 itself, the configuration of the seed structure, and the surface structure of the substrate surface at the bottom of the seed structure result in different structures in the obtained coating. The process based on the seed structure is highly flexible and can generate highly complex and varied structured coatings while maintaining relatively low manufacturing complexity and cost.

[0041] In some embodiments, it may be advantageous for the seed structure 104 to be relatively thin in order to reduce the effects of the seed structure (e.g., the optical effects of the seed structure) in the manufacturing apparatus including the seed structure and the structured coating. In some embodiments, the seed structure may have a width of at least about 10 nm, at least about 20 nm, or at least about 50 nm. In some embodiments, the seed structure may have a width of less than about 500 nm, less than about 200 nm, or less than about 100 nm.

[0042] In some embodiments, the seed structure may have a height of at least about 20 nm, at least about 50 nm, at least about 100 nm, or at least about 200 nm. In some embodiments, the seed structure may have a height of less than about 5 μm, less than about 2 μm, less than about 1 μm, or less than about 500 nm.

[0043] In some embodiments, the seed structures can be spaced apart from each other at a distance smaller than the wavelength of light, and the optical structure formed by the coating is configured to interact with it. This can suppress undesirable diffraction effects caused by the seed structures. In some embodiments, the seed structures can be spaced apart from each other at a distance of less than about 800 nm, less than 500 nm, or less than about 300 nm.

[0044] In some embodiments, the seed structure 104 and / or substrate 100 are formed of one or more polymers, hybrid polymers, epoxy resins, acrylics, thermoplastics, or resins. In some embodiments, the seed structure 104 and / or substrate 100 are formed of a material suitable for use as a replica in a replication process. In some embodiments, the seed structure 104 and / or substrate 100 are formed of a transparent material (e.g., a material that is transparent to the wavelength of light that interacts with the structured coating). In some embodiments, the seed structure 104 and / or substrate 100 are formed of a material suitable for providing coating 108. For example, if coating 108 is provided by an ALD process, the seed structure 104 and / or substrate 100 may be formed of a material that will not be degraded by the ALD process.

[0045] In some implementations, the base structure is formed as part of a replication process. Generally, replication refers to a technique that reproduces a given structure or its negative by means of etching, embossing, stamping, stamping, or molding. In a specific example of a replication process, the structured surface is embossed into a liquid, viscous, or plastically deformable material, which is then hardened, for example, by using ultraviolet radiation or heat curing, and the structured surface is then removed. Thus, a replica of the structured surface (in this case, a negative replica) is obtained.

[0046] Due to the structure applied by the structured surface, the composite structure provides mechanical, electrical, or optical functions (or a combination of those functions).

[0047] In some cases, replication can be implemented as a stamping process. In the case of a stamping process, it can also be called an embossing process, where the structured surface is the surface of a stamped part with liquid, viscous, or malleable material pressed into it (or having liquid, viscous, or malleable material pressed into it).

[0048] While the liquid, viscous, or malleable material in the imprinting process can be a bulk material (e.g., a block of material), in other embodiments, the liquid, viscous, or malleable material is a coating disposed on the surface of a substrate.

[0049] In an example of a replication process used to provide a seed structure on a substrate surface, photoresist can be deposited on a metal layer on a silicon wafer. For example, the photoresist can be patterned using photolithography or electron beam lithography, and etching (e.g., dry or wet etching) can be performed to create the pattern in the metal. One or more subsequent photolithography and / or etching steps can be performed to create a structured metal surface on the silicon wafer.

[0050] In some implementations, the structured metal surface on the silicon wafer can therefore be used as a master mold for generating the seed structure. For example, the structured metal surface can have a shape similar to... Figure 1A The structure is the opposite of the base structure 104. This structured metal surface can be pressed into a liquid, viscous, or malleable material to define the base structure 104 within the liquid, viscous, or malleable material. After one or more curing steps, the base structure 104 can be used to structure as described above. Figure 1B The coating mentioned above.

[0051] While replication can be used to form complex structures, in some embodiments, not all materials are perfectly suited to undergo replication processes. For example, some or all of the nitrides, oxides, and other materials that may be included in coating 108 as described above may not have sufficient fluidity, viscosity, or plasticity to be used as replicas in replication processes.

[0052] In particular, some materials with relatively high refractive indices (RI) for visible, ultraviolet, and / or infrared light may not have sufficient flowability, viscosity, or plastic deformation to be used as replicas in replication processes. As mentioned above, some or all of the nitrides, oxides, and other materials that may be included in coating 108 may have relatively high RI.

[0053] In various embodiments, high-RI materials may include materials having an RI of at least about 1.5 for visible, ultraviolet, and / or infrared light, and / or having an RI of at least about 2.0 for visible, ultraviolet, and / or infrared light, or having an RI of at least about 2.5 for visible, ultraviolet, and / or infrared light. In some embodiments, high-RI materials may include materials having a higher refractive index than other specific materials or components. For example, in some embodiments, coating 108 has a higher refractive index than the seed structure 104 and / or substrate 100, such that coating 108 may be referred to as a high-RI material compared to the seed structure 104 and / or substrate 100.

[0054] High-RI materials can be used in optical devices, including optical devices having coatings formed on a substrate as described in this disclosure. Coatings with high RI (e.g., structured coating 108) can interact with light more or less, or interact differently with light, thereby providing benefits for device operation. For example, compared to coatings formed from lower-RI materials, high-RI structured coatings can form diffractive optical elements with greater degree, precision, and / or efficiency of optical interactions (e.g., lensing or light bending). This can allow devices incorporating high-RI structured coatings to be more compact and / or more efficient than devices incorporating low-RI structured coatings.

[0055] Furthermore, using high-RI structured coatings in devices can help avoid or mitigate environmentally induced failure modes. For example, if a diffractive optical element formed by a structured coating is filled or covered by water, moisture, grease, or other accidental contaminants, its standard optical function may be impaired. If the RI of the diffractive optical element is close to that of the contaminant, its diffraction capability may be reduced, causing light (e.g., light from a focused light source) to pass through the diffractive optical element without forming the desired optical effect, leading to device malfunction. In some examples, misdirected light may pose health risks, such as eye damage.

[0056] Therefore, in some embodiments, it may be beneficial for the structured coating to be formed of or include a high-RI material, thereby increasing the RI difference between the coating and potential contaminants (which in some examples may have an RI between about 1.0 and about 1.5), thereby reducing or eliminating the potential harmful effects of the contaminants.

[0057] Using a replication process to manufacture such high-RI structured coatings can be advantageous in order to reduce manufacturing complexity, time consumption, and / or cost. However, as mentioned above, some high-RI materials may not be suitable for replication. Therefore, in order to manufacture high-RI structured coatings while reducing manufacturing complexity, a seed structure can be formed using replication, and then a coating can be applied to the seed structure, the corresponding height of which defines the local thickness of the coating used to form the high-RI optical element (as described above). In this embodiment, the seed structure has advantages over alternative manufacturing methods for forming high-RI optical elements.

[0058] Figure 2A-2C Further examples of methods including base seed structures are shown. For example... Figure 2A As shown, substrate 200 has a seed structure 204 disposed on substrate surface 202. Adjacent seed structures 204 have corresponding example groups with heights 206a, 206b and 206c.

[0059] like Figure 2B As shown, a coating 208 is provided on the substrate surface 202 and the seed structure 204. Due to the corresponding height of the seed structure 204, the coating 208 is structured to include, for example, ledges 218a, 218b, 218c having heights corresponding to the heights 206a, 206b, 206c of the bottom seed structure. As mentioned above, it can be manufactured in other ways that are more complex, time-consuming, and / or expensive. Figure 2B The coating 208 has a multi-level structure.

[0060] In some implementations... Figure 2B The structure shown is further processed to remove the coating 208 from portions of the substrate surface 202 on which the seed structure 204 is not disposed. For example, the coating 208 can be etched to produce... Figure 2C The apparatus 209 shown. Etching can remove a defined (e.g., predetermined) depth of the coating across the substrate surface 202, in some embodiments corresponding to the pre-etch thickness of the coating 208 on the portion of the substrate surface 202 on which the base seed structure 204 is not disposed (e.g., Figure 2B (thickness 211 in the middle).

[0061] In some embodiments, partially removing the coating 208 from the substrate can reduce or eliminate coating delamination, such as delamination during substrate dicing. Partial removal of the coating 208 from the substrate can also reduce or eliminate coating delamination during device stress. For example, temperature cycling, high temperatures, and / or high humidity can cause coating delamination in manufactured devices. Removing the coating from portions of the substrate on which no seed structure is disposed (e.g., leaving only the coating portion forming the optical structure defined by the seed structure) can reduce or eliminate such delamination.

[0062] After removing the coating 208 to a defined depth, the coating 208 may retain some or all of the structure that the coating 208 had before removal (e.g., as...). Figure 2C As shown, arms 218a, 218b, and 218c retain coating 208 even after the coating is removed, although the corresponding height of the arms relative to the substrate surface 202 is reduced.

[0063] In some implementations, etching can remove portions of coating 208 together with portions of the base structure 204.

[0064] In some embodiments, the seed structure 204 is retained in the device at the end of manufacturing. For example, even if the seed structure 204 remains intact within the coating 208, Figure 2C The device shown can also be used directly to provide optical functions. This can alter the optical properties of the device, at least because in some embodiments, the base structure can have a different RI than the coating.

[0065] In this implementation, the seed structure 204 can be designed to be relatively thin (as described above) to reduce the optical effects of the seed structure. Alternatively or additionally, the seed structure and / or coating 208 (including structures formed by coatings) can be designed with the optical performance of the seed structure in mind to achieve specific overall optical functions of the device.

[0066] Figures 3A-3E Further examples of methods and apparatus including a seed structure are shown. In this example, the seed structure is removed from the apparatus after the coating is applied.

[0067] like Figure 3A As shown, the substrate 300 has a seed structure 304 disposed on the substrate surface 302. In this example, the substrate surface 302 is stepped, for example including steps 320a, 320b, and 320c.

[0068] like Figure 3BAs shown, a coating 308 is provided on the seed structure 304 and the substrate surface 302. The corresponding heights of the seed structure 304 protruding from the steps of the substrate surface 302 at different heights define the local thickness of the coating 308.

[0069] The exposed or external surface 322 of the coating 308 has a profile corresponding to the profile defined by the distal surface (e.g., distal surface 324a, 324b) of the substrate structure 204. The bottom surface 326 of the coating follows the stepped surface 302 of the bottom of the substrate.

[0070] exist Figure 3B In the example, the base structure has a distal surface that is in line with the highest point (e.g., point 327) of the substrate surface 302. Therefore, the exposed surface 322 of the coating 308 has a substantially flat profile. In some embodiments, the substantially flat profile of the exposed surface 322 of the coating 308 may be useful (e.g., for providing a flat surface for receiving or transmitting light, or for providing a flat surface for attachment to a second substrate). In some embodiments, after the coating 308 is applied, the exposed surface 322 may be treated (e.g., mechanically and / or chemically) to flatten the exposed surface 322.

[0071] Without the seed structure 304, the coating 308 can conformally coat the stepped surface 302 at the bottom of the substrate, such that the exposed surface 322 generally follows the steps of the stepped surface 302. However, the presence of the seed structure 304 allows the coating 308 to have a substantially flat profile defined by the distal surface of the seed structure.

[0072] As described above, the structure of the stepped substrate surface 302 and / or the seed structure 304 can be formed by using a replication process (e.g., imprinting process).

[0073] like Figure 3C As shown, the second substrate 328 is attached to the exposed surface 322 of the coating 308. For example, the second substrate 328 may be bonded to the exposed surface 322 by an adhesive. In some embodiments, the second substrate 328 is directly bonded to the coating 308 based on the adhesion of one or both of the second substrate 328 and the coating 308.

[0074] In various embodiments, the second substrate 328 may include glass, Si, ZnSe, Ge, polymers, hybrid polymers, or other materials. In some embodiments, the second substrate 328 includes a transparent material (e.g., a material transparent to at least one of visible or infrared light, or a material transparent to the wavelength of light to which the coating is configured to interact), such that light can pass through the second substrate 328 and be transmitted to or from the coating 308 and the structure formed by the coating 308.

[0075] In some embodiments, the second substrate 328 is made of a high-RI material. As previously described, the substrate 300 and the seed structure 304 can be formed in a replication process such that, in some embodiments, the substrate 300 and the seed structure 304 have a lower refractive index than the coating 308. However, it may be advantageous to form the coating 308 on a high-RI material that is incompatible with the replication process (e.g., a high-RI second substrate 328 could provide optical performance benefits). Therefore, the structured coating 308 can initially be formed using a lower-RI seed structure 304 and subsequently transferred to a higher-RI second substrate 328.

[0076] like Figure 3D As shown, the substrate 300 and the seed structure 304 are removed, leaving a coating 308 bonded to the second substrate 328. A void 330 is retained at the location where the seed structure 304 was previously embedded in the coating 308. In this example, the void protrudes from the surface 331 of the coating toward the surface of the second substrate 328. The coating 308 includes portions of multiple thicknesses corresponding to the coating thickness previously defined by the steps of the seed structure 304 and the substrate surface 302.

[0077] For example, in some embodiments, the substrate 300 and the seed structure are made of a soluble material, such that... Figure 3C Immersion of some or all of the apparatus shown in a suitable solvent causes the substrate 300 and the seed structure 304 to dissolve, leaving Figure 3D The structure shown.

[0078] In some embodiments, coating 308 may be etched before or after transfer to the second substrate 328 (as referenced above). Figure 2C The above).

[0079] Compared to devices in which the base structure remains embedded in a structured coating. Figure 3D The structure can exhibit enhanced optical functionality (e.g., greater degree and / or precision of light interaction and / or control, or higher efficiency in optical performance). Enhanced optical functionality can be achieved at least because the void 330 can have a lower RI than the base structure 304.

[0080] like Figure 3E As shown, in some embodiments, voids 330 are filled by further adding coating material. The resulting device 332 includes a multi-level structured coating 308 on a second substrate 328. As previously mentioned, manufacturing the multi-level device 332 by other methods may be more expensive or time-consuming than using the methods disclosed herein, such as manufacturing the device 332 using a seed structure.

[0081] Because the voids 330 are filled, in some cases, device 332 can exhibit enhanced optical functionality (e.g., greater degree and / or precision of light interaction and / or control, or higher efficiency in optical performance) compared to devices where the voids are retained within the coating. Enhanced optical functionality can at least be achieved because the coating has a higher refractive index than the voids, resulting in a more optically consistent structure for incident light.

[0082] This can be achieved, for example, by using conformal deposition processes, such as atomic layer deposition, or as referenced above. Figure 1B The additional deposition process described above is used to further provide coating 308 to fill voids 330 (see [link]). Figure 3E ).

[0083] In some embodiments, further additions to the coating may include a coating material different from the coating material initially included in coating 308.

[0084] Although the surface of the coating has been shown to be flat (e.g., Figure 3B The exposed surface of the intermediate coating (322) may be uneven in some embodiments. For example, the coating surface may be wavy, with a higher surface profile at locations with a bottomed substrate structure and a lower surface profile at locations without a bottomed substrate structure.

[0085] For example, Figure 4 A scanning electron micrograph of a device including a coating 408 and a seed structure 404 on a substrate 400 is shown, the corresponding height of which defines the local thickness of the coating 408. Due to the presence of the bottom seed structure 404 on a selected area of ​​the substrate surface, the exposed or upper surface 440 of the coating 408 is wavy. The profile of the top surface of the structured coating can be taken into account when designing the device (e.g., in optical calculations predicting device performance).

[0086] In some embodiments, the profile of the exposed surface of the coating depends on one or more of the following: the deposition method of the coating, the thickness of the coating, the shape of the underlying seed structure and / or the configuration of the underlying seed structure (e.g., the lattice spacing of the seed structure lattice).

[0087] Figure 5An example of seed structures 504 (of various shapes) arranged on a substrate 500 is shown in a top view. Individual groups 550a, 550b, 550c, 550d of the seed structures 504 are arranged in an array or other configuration. In some embodiments, each group 550a, 550b, 550c, 550d can structure a coating disposed on the substrate 500 to create a corresponding optical element from the coating (e.g., by defining the local thickness of the coating based on the respective height of the seed structures 504). In this example (where the substrate surface 502 is flat), the structure of the coating depends on the respective height, shape, and configuration of the seed structures 504. For example, if all seed structures 504 have the same height, group 550a may result in a mesmerizing coating. As another example, if the seed structures 504 have different heights, group 550a may result in a coating with a pyramid or dome shape.

[0088] As described above, in some embodiments, the seed structure can be arranged to have various shapes and patterns, each shape and pattern corresponding to a different structure formed by the resulting coating.

[0089] After the coating is applied, the bottom substrate 500 (and the coating) can be cut along the cutting track 552. After cutting, the coating associated with each array 550a, 550b, 550c, 550d forms part of the corresponding individualized optical device.

[0090] Before or after cutting, the coating may be etched as described above, such that the coating remains only on portions of the substrate including the seed structures 550a, 550b, 550c, and 550d.

[0091] In some embodiments, an apparatus manufactured using a process including the aforementioned basic structure, or an apparatus having one or more of the aforementioned characteristics, can be integrated into an optoelectronic module or other module. For example... Figure 6 As shown, module 600 includes a substrate 602 and a light-emitting component 604 coupled to or integrated into the substrate 602. The light-emitting component 604 may include, for example, a laser (e.g., a vertical cavity surface-emitting laser) or a light-emitting diode.

[0092] The light 606 generated by the light-emitting component 604 is transmitted through the housing and then to the optical device 608, for example, as... Figure 1B , 2BThe optical device is shown in 2C, 3B, 3D, or 3E. As described above, the optical device 608 can be operated to alter the light 606 as it passes through the optical device 608, such that the altered light 610 exits the module 600. For example, the module 600 can use the optical device 608 to generate one or more of structured light, diffused light, or patterned light. The housing may, for example, include spacers 612 that separate the light-emitting element 604 and / or the substrate 602 from the optical device 608.

[0093] In some implementations... Figure 6 Module 600 is a photosensitive module (e.g., an ambient light sensor), component 604 is a photosensitive component (e.g., a photodiode, pixel, or image sensor), light 606 is incident on module 600, and when light 610 passes through optical device 608, light 610 is altered by optical device 608. For example, optical device 608 can focus patterned light onto photosensitive component 704.

[0094] In some embodiments, module 600 may include both a light-emitting component and a photosensitive component. For example, module 600 may emit light that interacts with the environment in which it is received, and this light is then received back by module 600, allowing module 600 to function, for example, as a proximity sensor or as a three-dimensional mapping device.

[0095] The aforementioned modules can be, for example, part of a time-of-flight camera or an active stereo camera. These modules can be integrated into systems such as mobile phones, laptops, wearable devices, or autonomous vehicles.

[0096] Because of the inclusion of a seed structure as part of the manufacturing process of module 600, in some cases, module 600 can be manufactured in a less expensive, less time-consuming, and / or simpler manner than equivalent modules manufactured in other ways. In some embodiments, the use of a seed structure can enable a structured coating made of a high-RI material, enhancing module operation, increasing module security, and / or increasing the compactness of module 600.

[0097] While this disclosure sometimes relates to optical devices, the methods, apparatuses, and modules described are not limited to, nor are they required to include, optical functions. For example, structured coatings (in various embodiments, the coating is created at least in part based on a substrate structure, has a substrate structure, or has voids) can be applied and processed to manufacture non-optical devices, or devices having both optical and non-optical functions.

[0098] While specific implementations have been described in detail, various modifications can be made. As an example, the processes depicted in the figures do not necessarily require the specific order or sequence shown to achieve the desired results. In some implementations, multitasking and parallel processing may be advantageous. Therefore, other implementations are within the scope of the claims.

Claims

1. A method comprising: Multiple seed structures are arranged on the surface of a substrate using a replication process, wherein the height of at least some of the seed structures differs from the height of the other seed structures. A coating is formed on the surface of the substrate, wherein the coating completely fills the space between adjacent substrate structures of different heights. The corresponding height of the base structure defines the local thickness of the coating. The plurality of said base structures and the local thickness of said coating together define the diffractive optical element, which is a lens. The coating is configured by depositing the coating using a surface growth technique, and the coating is grown at least partially from the surfaces of the plurality of seed structures such that the coating extends a first thickness above the top surface of each seed structure, and the spacing between adjacent seed structures is less than twice the first thickness.

2. The method according to claim 1, wherein the plurality of seed structures are arranged on a stepped surface at the bottom of the substrate. The exposed surface of the coating has a profile corresponding to the profile defined by the distal surface of the base structure. The bottom surface of the coating follows the stepped surface of the bottom of the substrate.

3. The method of claim 1, wherein the coating is deposited using atomic layer deposition or chemical vapor deposition.

4. The method according to claim 1, wherein the plurality of base structures include at least one of columnar structures or walls.

5. The method of claim 1, wherein the plurality of seed structures are protrusions from the surface of the substrate.

6. The method according to claim 1, further comprising: After the coating is applied, a portion of the coating is removed such that at least the portion of the substrate on which the substrate structure is not disposed is not covered by the top coating. Wherein, the removal of a portion of the coating is configured such that, after the removal of a portion of the coating, the coating completely fills the space between the base structures that have different heights and are adjacent to each other.

7. The method of claim 1, wherein the substrate is a first substrate, and wherein the method further comprises: The second substrate is attached to the exposed surface of the coating, and Remove the first substrate and the seed structure.

8. The method according to claim 7, further comprising: After removing the first substrate and the seed structure, other coatings are applied such that the voids left by the removed seed structure are filled by the other coatings.

9. The method according to claim 1, The process involves arranging multiple seed structures on the surface of a substrate using a replication process, including imprinting receiving material to form the seed structures on the surface of the substrate.

10. An optical device, comprising: Substrate; The substrate has a plurality of seed structures on its surface, wherein at least some of the seed structures have a different height than the other seed structures, and a coating on the seed structures and the surface of the substrate. The coating is in contact with the top surface and sidewalls of each of the plurality of substrate structures, and the coating extends beyond the top surface of each substrate structure by a first thickness, with the spacing between adjacent substrate structures being less than twice the first thickness. The plurality of said base structures and the local thickness of said coating together define the diffractive optical element, which is a lens. The coating completely fills the space between adjacent substrate structures of different heights. The corresponding height of the base structure defines the local thickness of the coating.

11. The optical device of claim 10, wherein the plurality of base structures are protrusions from the surface of the substrate.

12. An optical device, comprising: Substrate; and The coating on the surface of the substrate Multiple voids are formed in the coating. The coating forms at least one optical element. The gaps therein protrude from the surface of the coating toward the surface of the substrate. The portion of the coating in which the voids are formed includes at least two different thicknesses. The coating has the same thickness from the substrate to each void, and the coating has different thicknesses in at least two different regions between adjacent voids.

13. A module comprising: At least one of a light-emitting device or a photosensitive device; and The optical device according to any one of claims 10-12, The optical device is configured to (i) interact with light generated by the light-emitting device or (ii) interact with light incident on the module such that light passing through the optical device is received by the photosensitive device.

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