Characterization of manufacturing tolerances in nanostructured optics

Abstract

A test structure for a component having nanostructures is provided, wherein the test structure and the component share a substrate. The test structure includes a plurality of optical nano-elements on the substrate, wherein each of the optical nano-elements is arranged in an arrangement position. Any one of a structure of the optical nano-elements and an arrangement of the arrangement positions are configured such that the plurality of nano-elements comprise at least a predetermined first optical resonance frequency and a predetermined second optical resonance frequency.

Description

[0001] 2023P00492 - 1 – CHARACTERIZATION OF MANUFACTURING TOLERANCES IN NANOSTRUCTURED OPTICS Description This disclosure generally relates a characterization of nanostructures, e.g. of a nanostructures of an optical component. Characterization of nanostructures can include any one of a height, a wall angle, a diameter and a width of the nanostructures. Nanostructures are typically characterized using scanning electron microscopy (SEM) which can be a rather time-consuming and costly characterization method. Thus, an improved characterization method is needed that provides fast and non-destructive characterization of nanostructures. It is an objective of the invention to provide an alternative characterization method to an SEM for characterizing nanostructures. In one aspect, a test structure for a component having nanostructures is provided. The test structure and the component share a substrate. The test structure includes a plurality of optical nano-elements on the substrate. Each of the optical nano-elements is arranged in an arrangement position. Any one of a structure of the optical nano-elements and an arrangement of the arrangement positions are configured such that the plurality of nano-elements comprise at least a predetermined first optical resonance frequency and a predetermined second optical resonance frequency. The invention is set out in the appended set of claims. The provided characterization method is an optical method, scalable and suitable for characterization in a mass production. An optical characterization measurement can illuminate a significant surface in comparison to what a SEM can measure, and thus using an optical test structure provides a faster method to characterize a larger surface. The optical 2023P00492 - 2 – characterization measurement exploits optical resonant characteristics of nanostructures on a surface to be analyzed, and their shift in wavelength spectrum allows extracting information about the manufacturing tolerances. This way, the optical characterization measurement provides a fast and non- destructive characterization method that is well suited for the mass production of nanostructured components. Further, an optical device having the test structure is provided. The optical device includes the test structure having a resonant nanostructure adjacent or integrated in one or more optical components of the optical device. Optical components can be any one of a grating, a DOE, a metalens etc. Resonant properties in the optical spectrum in transmission or reflection of the test structure allow extracting manufacturing tolerances of the optical component using the same or similar nanostructures. Further, a method of testing manufacturing variations of a component having nanostructures is provided. The method includes forming the nanostructures of the component and a test structure on a shared substrate using at least one shared manufacturing tool. The test structure may be configured according to any one of the above-mentioned Examples. The method may further include determining an optical spectrum of the test structure. The optical spectrum includes at least a first optical resonance corresponding to the first subset of nano-elements of the test structure, and a second optical resonance corresponding to the second subset of nano-elements of the test structure. The method may further include determining a manufacturing tolerance of the at least one shared manufacturing tools based on the determined optical spectrum. In case the determined manufacturing tolerance exceeds a predetermined threshold value, the method may include adjusting at least one parameter of the at least one shared manufacturing tool. 2023P00492 - 3 – In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various aspects of the invention are described with reference to the following drawings, in which: FIG.1A to FIG.1L show diagrams illustrating the test structure for manufacturing a component having nanostructures; FIG.2A to FIG.2B illustrate a test structure according to an aspect of the invention; FIG.3A to FIG.3B illustrate a test structure according to an aspect of the invention; FIG.4A to FIG.4B illustrate a test structure according to an aspect of the invention; FIG.5 illustrates a test structure according to an aspect of the invention; FIG.6 illustrates a test structure according to an aspect of the invention; FIG.7 illustrates a test structure according to an aspect of the invention; FIG.8 illustrates a test structure according to an aspect of the invention; FIG.9A and FIG.9B illustrate a test structures according to an aspect of the invention; FIG.10A and FIG.10B illustrates a test structure according to an aspect of the invention; 2023P00492 - 4 – FIG.11 is a flow diagram of a method to manufacture a component according to an aspect of the invention. The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and aspects in which the disclosure may be practiced. One or more aspects are described in sufficient detail to enable those skilled in the art to practice the disclosure. Other aspects may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the disclosure. The various aspects described herein are not necessarily mutually exclusive, as some aspects can be combined with one or more other aspects to form new aspects. Various aspects are described in connection with methods and various aspects are described in connection with devices. However, it may be understood that aspects described in connection with methods may similarly apply to the devices, and vice versa. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures. Throughout the drawings, it should be noted that proportions are not necessary to scale and that the size of features may be emphasized for ease of illustration. The term "arranged on" does not necessarily mean directly adjacent to it, other layers can also be provided in between. The electrode(s) is / are preferably in one piece with the lens component, e.g. cannot be separated from it without destroying it (without destroying the electrode, lens component and / or a layer in between). Optical resonances are sensitive to substantially all manufacturing parameters of nanostructures. Thus, the test structure provides a diagnostic tool for components utilizing nanostructures, e.g. for optical components using nanostructures, e.g. an optical component having a metalens. The test structure can be easily characterized by sweeping a wavelength of incoming light emitted from an adjustable light source. A wavelength shift of the resonance wavelength of a 2023P00492 - 5 – single resonance in the determined spectrum of the test structure contains information about the substantial manufacturing tolerance parameters of the nanostructures of the test structure (also denoted as nano-elements) corresponding to nanostructures of the component, e.g. diameter, height, and wall angle of the nano-elements of the test structure. The manufacturing tolerance parameters of the test structure can correspond to the manufacturing tolerance parameters of the component having the nanostructure, e.g. in case the test structure and the component are formed using the same tools, e.g. in parallel or subsequently. Optical resonances of nano-elements are very narrow band in respect to any one of a diameter of the nano-element, a height of the nano-element, a wall angle of the nano-element, a pitch between adjacent nano-elements, and a wavelength of the light source used to determine the wavelength spectrum of the test structure. For example, a test structure having three different resonances which may have different sensitivity to the manufacturing parameters provides a system of coupled equations allowing to determine various manufacturing tolerances. Thus, resonant properties of the test structure in the optical spectrum in transmission or reflection can be used to extract manufacturing tolerances of the manufacturing method to the component. The test structure may be arranged adjacent or integrated in the footprint of the component. An optical component as an example of component having nanostructures can be any kind of optical component, e.g. a gratings, a lens, a prism, a grism, a microlens array, a metalens etc., e.g. a differential optical element (DOE). Thus, the test structure allows characterizing most important parameters of the optical device in the manufacturing process. Illustratively, an optical test structure for components having nanostructures is provided allowing to illuminate a significant surface in comparison to what a SEM can measure. The optical resonant characteristics of the test structure can be determined and their shift in wavelength spectrum can be used 2023P00492 - 6 – to extract information about the manufacturing tolerances of the component. This allows a fast and non-destructive characterization of manufacturing tolerances of the component that is well suited for a mass production of components. Throughout this specification, a test structure for a component having nanostructures is provided to determine manufacturing tolerances using a fast and cost-efficient optical measuring method. The test structure may be configured as a metalens having a plurality of optical nano-elements. The optical nano- elements can have a shape and pitch depending on the manufacturing tolerances of the component having the nanostructures. For ease of description, the optical nano- elements may also be denoted as pillars, e.g. having a circular or elliptical shape in top view on the substrate on which the nano-elements are formed. However, the optical nano-elements denoted as pillars can have a shape different from a pillar. The test structure has a plurality of optical nano-elements that are optically coupled with each other. The test structure may be used in conjunction with a coherent light source, e.g. a laser diode or vertical cavity side emitting laser diode (VCSEL), to determine the optical spectrum of test structure. The optical spectrum may indicate the wavelength dependent transmission or reflection of the test structure (e.g. see FIG.1E). The optical spectrum may allow determining the physical structure of the nano-elements, and to determine a deviation of the determined physical structure from an intended physical structure. This way, manufacturing tolerance of the tools used to form the nano-elements can be determined. Thus, nanostructures of a component formed using the tools used to form the nano-elements of the test structure may have corresponding manufacturing tolerances as the ones determined for the test structure. Thus, the manufacturing tolerances of the nanostructures of the component can be determined in an indirectly in a fast and cost-efficient manner. FIG.1A illustrates a schematic cross-sectional view and FIG.1B illustrates a schematic top view of a test structure 100. The 2023P00492 - 7 – test structure 100 includes a plurality of nano-elements (also denoted as pillars or nanostructures) 102-i arranged on an optically transparent substrate 104. In the following, nano- elements 102-i are denoted as pillars for ease of description only. The pillars 102-i may be are arranged in a regular, predetermined pattern on the substrate 104 – in FIG.1A and FIG.1B illustrated as an alignment of a center 122 of the pillars with a grid position 120 (see FIG.1B), respectively. Note that nanostructures of a component may be arranged on the substrate 104, as illustrated in FIG.8A to FIG.9A. The nanostructures of the component may be an optical component configured for any kind of usage for any one of a lens, a grating, a prism, a grism, a mirror, an optical tap, a metalens. The nanostructures of the component may be used in a projection system for example, e.g. in augmented reality (AR) glasses or virtual reality (VR) glasses. The component may be used in conjunction with a vertical cavity surface emitting laser (VCSEL) as light source or as part of the VCSEL. A coating layer 112 may be formed on or above the substrate 104 and the pillars 102-i. Light 180 (see FIG.1A) from a light source 190 passes through the substrate 104, the pillars 102-i and the coating layer 112. The substrate 104 may be an optically transparent substrate 104, e.g. regarding light 180 emitted towards the test structure 100 from a light source 190 used in conjunction with the test structure 100. Typically, an arrangement of optically coupled pillars 102-N (i being any one between 1…N with N being an integer) has a resonance in the pillar library frequency (or resonance wavelength) depending among others on the size (e.g. diameter 106) and pitch 108 of the pillars 102-i forming the arrangement - see FIG.1A and FIG.1C. FIG.1C illustrates a diagram showing the phase of light transmitted by an arrangement of optically coupled pillars 102-N depending on the diameter of pillars 102- N forming the arrangement of optically coupled pillars 102-N. 2023P00492 - 8 – As illustrated, the arrangement of optically coupled pillars 102-N may reflect light 180 of the light source 190 corresponding in its frequency to the resonance frequency of the arrangement of optically coupled pillars 102-N. Further, the resonance is not caused by the geometry of a single pillar, but it is a collective phenomenon of optically coupled pillars in the arrangement of optically coupled pillars 102-N. The resonance is caused by secondary waves propagating in the plane of pillars when a pillar receives light 180 from the light source 190, as illustrated in the top view of the schematic metalens in FIG.1D. The secondary wave has a propagation radius, and in case the frequency of the light 180 from the light source 190 corresponds to the resonance condition of the pillars within the propagation radius, causes the resonance illustrated in FIG.1C. That is, in a metalens there is light transmitted directly and higher orders of transmitted light may be coupled within the plane of the pillars and propagate in the lateral direction as secondary waves. The secondary waves may re-radiate in the direction of the directly transmitted beam with a phase shift of π. In other words, resonances propagate as evanescent diffraction orders, e.g. Bloch waves propagating along the polarization of the incident light. Notice that the phase shift corresponding to the diameter of the pillar at the resonance may be close to the value of π. In other words, in a metalens there may be two waves competing against each other near the resonance, i.e. the directly transmitted beam (primary wave) and laterally propagating secondary wave. At the resonance itself, the two waves become exactly the same in amplitude, but have a phase shift of π which leads to the complete cancellation of the waves in the transmission region and all the power is reflected back towards the light source. Further, the resonance frequency can be dependent on the angle of incidence of the light 180 from the light source 190, and thus an arrangement of optically coupled pillars 102-N with pillars corresponding to the frequency of the light source 190 2023P00492 - 9 – may have a resonance reflection for a certain range of incidence angles of the light 180 from the light source 190. In other words, for determining the optical spectrum of the test structure 100, the light source 190 may be configured to emit a coherent radiation 180 having a coherence length. The test structure 100 may be arranged within the coherence length of the light source 190 such that the light source emits coherent radiation towards the test structure 100. The optical nano-elements 102-i within a predetermined area adjacent to a nano-optical element 102-i of the plurality of optical nano-elements 102-i may be substantially laterally optically coupled. Optically coupled may be understood that the optical nano-elements 102-i may cause an optical resonance in the optical spectrum. The predetermined area may depend on a wavelength of a light source 190 used in conjunction with the test structure 100. Thus, the predetermined area can be application-specific. The test structure 100 can be configured for a certain light source 190. The predetermined area may be defined by a propagation radius (see also FIG.1D) of a light 180 emitted towards the test structure 100 from the light source 190 used in conjunction with the test structure 100 as a minimum. The propagation radius may correspond to a range between 0.25 to 11 times the wavelength of the light 180 emitted towards the test structure 100 from a light source 190 used in conjunction with the test structure 100. However, the predetermined area can be much larger than the propagation radius. This way, in order to extract two or more manufacturing tolerances, e.g. a nanostructure height, a diameter, a wall angle, or any combination thereof, an equal number of test structures may be designed. Designing of different test structures may be difficult. However, the test structures may be illuminated at different angles of incidence, e.g. shining light at the structure not at normal incidence, but for example at 45 degrees. This way, the 2023P00492 - 10 – test structures may show different resonances when illuminated at different angles of incidence. Thus, there may be no need to design different test structures. FIG.1E illustrates an optical spectrum, e.g. a relative transmission 152 of the test structure as a function of the wavelength 150 of the light 190 for test structures in the shape of pillars having a diameter of 234 nm, 236 nm, 238 nm, 240 nm, 242 nm. As illustrated, the resonance wavelength change for the arrangement of pillars increases of about 5 nm for every 2 nm increase in pillar diameter. Thus, by performing a wavelength scan on manufactured test structures, the position of the resonance wavelength in the optical spectrum and its deviation ∆ Wminfrom the nominal design 154 can be determined as a function of the deviation of the diameter ∆D of the pillars. In other words, the deviation of the resonance wavelength ∆ Wminis a function of the deviation of the diameter ∆ ^^ of the pillars - ∆ Wmin= ∆ Wmin(∆D) Thus, the manufacturing tolerance of pillar diameter ∆D(∆Wmin) can be determined, as illustrated in the diagram of FIG.1F the wavelength corresponding to resonance as a function of pillar diameter 150, and thus showing ∆ Wmin(∆D) 156. In other words, the test structure allows to determine a functional dependence ∆D = ∆D(∆Wmin) and to optically measure diameter tolerances of nanostructures. Optical resonances of nano-elements can be very narrow band in respect to any one of a diameter of the nano-element ∆ ^^, a height of the nano-element ∆H, a wall angle of the nano-element ∆A, a pitch between adjacent nano-elements ∆P, and a wavelength of the light source used to determine the wavelength spectrum of the test structure. Thus, ∆ Wminmay not be a single variable function, but a multivariable function: ∆Wmin= ∆Wmin(∆D, ∆H, ∆A, ∆P). 2023P00492 - 11 – Manufacturing tolerances may be within 5% of the nominal values, and thus allow considering a linear slope at the nominal design value. Further, application-specific and manufacturing-specific, one or more of the variables can be controlled better than others. For example, a pitch between adjacent pillars may be very well controllable for optical nano-elements, and hence the pitch variation ∆P may be set or assumed to be 0. Thus, it may follow that ∆Wmin= ∆Wmin(∆D, ∆H, ∆A, ∆P=0). This way, the first derivative of ∆Wminmay be estimated as: or stated differently: ∆ ^^ ^^ ^^ ^^= ^^1∆ ^^ + ^^2∆ ^^ + ^^3∆ ^^ (2) Thus, there may be more than one single valued inverse function ∆ ^^ = ∆ ^^ ∆ ^^ ^^ ^^ ^^, and the information measured in ∆ ^^ ^^ ^^ ^^ may be scrambled. However, determining ∆ ^^ ^^ ^^ ^^ for more than one resonance allows determining further manufacturing tolerance. As an example, one resonance per manufacturing tolerance to be determined may be used. A test structure having three different resonances which may have different sensitivity to the manufacturing parameters provides a system of coupled equations allowing to determine various manufacturing tolerances. As an example, the test structure may include a plurality of subsets of nano-elements 160, 162, 164 (see FIG.1G, FIG.1H, and FIG.1J) wherein the nano elements of each subset 160, 162, 164 corresponds to a different (relative) manufacturing tolerance. Corresponding to FIG.1F - FIG.1G, FIG.1H and FIG.1J illustrate the spectrum as resonance shift as a function of the diameter ∆ ^^ (FIG.1G - also denoted as lateral extension in case of non- circular nano-elements, e.g. grooves), height ∆ ^^ (FIG.1H) and wall angle ∆A (FIG.1J) of the nano-elements of the subsets of nano-elements for a first resonance. The measured spectrum results in the coefficients a11, a12, a13for the first resonance according to eq. 2. Similarly, the coefficients a21, a22, a23can 2023P00492 - 12 – be determined for a second resonance, and the coefficients a31, a32, a33can be determined for a third resonance as illustrated in FIG.1K. In other words, ∆W1,,∆W2, ∆W3can be determined using a measurement using the optical spectrum of the test structure having a plurality of subsets of nano-elements 160, 162, 164 and the coefficients a11, …, a33can be modelled based on manufacturing tolerances. For example, by measuring optical spectrum of a test structure have three subsets of nano-elements each having an optical resonance and monitoring the resonance shift in wavelength spectrum, information about the manufacturing tolerances of Diameter ∆D, Height ∆H and wall angle ∆A can be determined, as illustrated in FIG.1L. . Thus, resonant properties of the test structure in the optical spectrum in transmission or reflection can be used to extract manufacturing tolerances of the manufacturing method to the component. Subsequently, various aspects for implementing a test structure having at least a first resonance and a second resonance. The origin of the first resonance and the second resonance may be independent from each other. In other words, the second resonance may not be a higher order of the first resonance, or vice versa. Note that the aspects can be used alone or in any combination. The substrate 104 may be any one of amorphous silica, glass, etc., e.g. a plastic, e.g. a polycarbonate substrate or an epoxide substrate. The substrate 104 may have a planar shaped, e.g. may be a wafer. Alternatively, the substrate may have a bowed shaped, e.g. glass of AR- or VR-glasses. The coating layer 112 may be any kind or organic or inorganic material having a refractive index of about 1.50 for the light received from a light source. The coating layer 112 may at least partially fill over overfill the space between the optical nano-elements 2023P00492 - 13 – The optical nano-elements 102-i may have a height in a range from about 10 nm to about 10000 nm, e.g. in a range from about 200 nm to about 1600 nm, e.g. in a from about 450 nm to about 800 nm. The optical nano-elements 102-i may have a lateral extension in a range from about 10 nm to about 1000 nm, e.g. in a range from about 50 nm to about 700 nm, e.g. in a from about 100 nm to about 350 nm. The optical nano-elements 102-i may have a tapering angle in a range from about 80 ° to about 90 °, e.g. in a from about 82 ° to about 90°, e.g. in a from about 85 ° to about 88°. Further, optical components may be arranged on a surface of any one of a surface of the substrate opposite to the optical nano- elements 102-i, the optical nano-elements, and the coating layer 112. Any one of a structure of the optical nano-elements and an arrangement of the arrangement positions may be configured such that the plurality of nano-elements may include at least a predetermined first optical resonance frequency and a predetermined second optical resonance frequency. The plurality of the nano-elements may include a first subset of the nano- elements configured to include the predetermined first optical resonance frequency, and a second subset of the nano-elements configured to include the predetermined second optical resonance frequency. The plurality of nano-elements further may including at least a third subset of nano-elements, wherein the nano-elements of the third subset differ in at least one characteristic from the nano-elements of the first subset and the second subset such that the third subset of nano-elements may include a third optical resonance. The nano-elements of the third subset differ in at least one characteristic from the nano-elements of the first subset and the second subset according to any one of a distance between adjacent optical nano-elements of the subset, a lateral extension of the optical nano-elements of the subset, a height of the optical nano-elements of the subset, a shape of optical nano-elements of the subset, and a tapering angle of 2023P00492 - 14 – the optical nano-elements of the subset. For ease of explanation, nano-element of the first subset and the second subset are described. As an example, the nano-elements of the first subset may be arranged in a first distance respectively adjacent to each other. The nano-elements of the second subset may be arranged in second distances respectively adjacent to each other. The second distance may be different from the first distance. FIG.2A illustrates a cross-sectional view, and FIG.2B illustrates a top view of a test structure 100 illustrating nano-elements of a lateral extension 106, wherein nano-elements 102-i of a first subset are arranged in a first distance 108 and nano-elements 102-i of a second subset are arranged in a second distance 110 from each other. A spacing, e.g. distance 108, 110, may be formed between any of the subsets of nano-elements on a surface of the substrate 104. The spacing, e.g. center-to-center distance or the sidewall-to- sidewall distance, may be constant between the optical nano- elements. However, the different lateral extensions may be combined with any one of the different distances, and the different shapes and orientations of the optical nano-elements as described before. The optical nano-elements of the first subset and the optical nano-elements of the second subset may be arranged intertwined on a surface of the substrate 104. Any of the first subset and second subset of the plurality of nano-elements may include ellipsoidal pillar shaped nano- elements may including a first axis and a second axis orthogonal to the first axis, wherein the extension of the ellipsoidal pillar in the direction of the second axis may be shorter than the extension of the ellipsoidal pillar in the direction of the first axis. FIG.3A illustrates a cross- sectional view, and FIG.3B illustrates a top view of a test structure 100 illustrating elliptical nano-elements of a first 2023P00492 - 15 – subset and a second subset having different orientations, e.g. having different lateral extensions in a first orientation. An ellipsoidal pillar shape may include a first axis and a second axis orthogonal to the first axis, e.g. regarding a focal point of the ellipse as origin. The second axis may be shorter than the first axis. The first axis and the second axis of the second optical nano-elements 102-i may be arranged in different orientations on a surface of the substrate 104. This way, the optical nano-elements 102-i can have different distances 108, 110 between each other, as illustrated in FIG.3B. Note that a center axis of the ellipse of each of the optical nano-elements 102-i can be arranged in a regular grid, e.g. a regular pattern or array. Alternatively, or in addition, the nano-elements of the first subset have a first lateral extension and the nano-elements of the second subset have a second lateral extension, wherein the second lateral extension may be different from the first lateral extension. FIG.4A illustrates a cross-sectional view, and FIG.4B illustrates a top view of a test structure 100, illustrating nano-elements of a first subset having a first lateral extension 106 and nano-elements of a second subset having a second lateral extension 116. Different lateral extensions of the optical nano-elements 102-i may correspond to different adiabatic periodic boundary conditions of the subsets of nano-elements. Thus, a resonance in the phase spectrum of the test structure may be adjusted by the optical nano-elements of different lateral extensions. Alternatively, or in addition, the nano-elements of the first subset have a first tapering angle and the nano-elements of the second subset have second tapering angle, wherein the second tapering angle may be different from the first tapering angle. FIG.5 illustrates a cross-sectional view of a test structure 100, illustrating nano-elements of various tapering angle “a”. Different tapering angles “a” of the optical nano-elements 102- i may correspond to different adiabatic periodic boundary conditions of the optical metalens component. Thus, a resonance 2023P00492 - 16 – in the phase spectrum of the optical metalens component may be flattened by the optical nano-elements of different tapering angles “a”. Note that the term tapering angle may refer to any one of the angles larger than 90° (case I in FIG.5), equal to 90° (case II in FIG.5), or smaller than 90° (case III in FIG.5). Thus, the optical nano-elements 102-i of the second subset may be formed having different tapering angles regarding the nano-optical element of the first subset on the substrate 104. The nano-elements of the first subset may be spaced apart from the nano-elements of the second subset such that the first subset of nano-elements may be laterally optically decoupled from the second subset of nano-elements. FIG.6 illustrates a top view of a test structure 100 illustrating nano-elements of a plurality of subset 140-1, 140-2, 140-3, 140-4 arranged in distances 142, 144 from each other such that the subsets 140-1, 140-2, 140-3, 140-4 of nano-elements are optically decoupled from each other. In another aspect, illustrated in a top-view in FIG.6, the nano-elements within the predetermined area may correspond to at least a first subset 140-1 of nano-elements and a second subset of nano-elements 140-2, e.g. a plurality of subsets 140- M (with 1, 2, …, j…, N, i ≤ N, and j, M being integer). The nano-elements of the first subset may differ in at least one characteristic from the nano-elements in the second subset. For example, the nano-elements of the first subset may differ in at least one characteristic according to any one of distance between adjacent optical nano-elements 102-i of the subset, lateral extension of the optical nano-elements 102-i of the subset, shape of optical nano-elements 102-i of the subset, and tapering angle of the optical nano-elements 102-i of the subset as described above. The optical nano-elements 102-i of the first subset 140-1 and of the second subset 140-2 may be arranged intertwined on a surface of the substrate 104. Alternatively, the optical nano-elements 102-i of the second subset 140-2 may be spaced apart from the optical nano-elements 102-i of the first subsets 140-1 such that the first subset may 2023P00492 - 17 – be optically decoupled from the second subset, as illustrated in FIG.6. As an example, the distances 142, 144 between adjacent subset may be larger than the propagation radius of Bloch waves. Each of the subsets may further include any one of different tapering angles, different lateral extensions, different distances, and different non-circular shapes and orientations of the optical nano-elements as described before. Alternatively, or in addition, the nano-elements of the first subset may include a first shape and the nano-elements of the second subset may include a second shape, wherein the second shape may be different from the first shape. The nano-elements 102-i of the first subset 140-1 may be pillars on the substrate 104, and the nano-elements 102-i of the second subset 140-2 may be grooves on the substrate 104, as illustrated in the SEM images shown in FIG.7. Alternatively, or in addition, the nano-elements of the first subset have a first height and the nano-elements of the second subset have second height, wherein the second height may be different from the first height. The plurality of the nano-elements may be arranged in a regular pattern, as illustrated in the schematic top view in FIG.8. The arrangement of the arrangement position may correspond to a regular grid of positions, wherein each arrangement position corresponds to a grid position. The regular grid may be any one of a monoclinic grid, an orthorhombic grid, a tetragonal grid and a hexagonal grid. Alternatively, or in addition, the nano-elements of the first subset include a first material having a first refractive index and the nano-elements of the second subset include a second material having a second refractive index respectively. The refractive index of the optical nano-elements may be amended in a post-processing, e.g. using an ion implantation or doping. Different refractive indices of the optical nano-elements 102-i 2023P00492 - 18 – may correspond to different adiabatic periodic boundary conditions of the optical metalens component. Thus, a resonance in the phase spectrum of the optical metalens component may be adjusted by the optical nano-elements of different refractive indices. FIG.9A and FIG.9B illustrate top views of optical devices 900 having an optical component 902 and a test structure 100 as described above on a shared substrate 104. The optical component 902 may include a foot print. The test structure 100 may be arranged within the foot print of the optical component 902, as illustrated in FIG.9B. Alternatively, the test structure 100 may be arranged adjacent to the foot print of the optical component, as illustrated in FIG.9A. FIG.10A and FIG.10B illustrate top views of optical devices 900 having an optical component 902 and a test structure 100 as described above on a shared substrate 104. The optical device 900 may include at least a first optical component 902 and a second optical component 902 arranged on a shared substrate 104. The substrate 104 may include a separation region 1002 configured to separate the first optical component and the second optical component from each other. The test structure 100 may be arranged in the separation region 1002. FIG.10A illustrates the optical device 900 before separation, and FIG.10B illustrates the separated optical devices 900-1, 900-2 after separation along the separation region. FIG.11 shows a flow diagram of a method 1100 to for manufacturing a component having nanostructures. The method 1100 includes forming 1102 the nanostructures of the component and a test structure on a shared substrate using at least one shared manufacturing tool. The test structure may be configured according to any one of the above-mentioned Examples. The method 1100 may further include determining an optical spectrum of the test structure. The optical spectrum includes at least a first optical resonance corresponding to the first subset of nano-elements of the test structure, and a second optical resonance corresponding to the second subset of nano-elements 2023P00492 - 19 – of the test structure. The method 1100 may further include determining 1104 a manufacturing tolerance of the at least one shared manufacturing tools based on the determined optical spectrum. In case the determined manufacturing tolerance exceeds a predetermined threshold value, the method may include adjusting 11060at least one parameter of the at least one shared manufacturing tool. The nanostructures of the component and the test structure may be formed at least in part in parallel. The method may further include any feature as described for the device above. In the following some examples are described, which relate to what is described herein and shown in the figures. Example 1 is a test structure for a component having nanostructures. The test structure and the component share a substrate, the test structure including: a plurality of optical nano-elements on the substrate, wherein each of the optical nano-elements is arranged in an arrangement position, wherein any one of a structure of the optical nano-elements and an arrangement of the arrangement positions are configured such that the plurality of nano-elements include at least a predetermined first optical resonance frequency and a predetermined second optical resonance frequency. In Example 2, the subject matter of Example 1 can optionally include that the plurality of the nano-elements includes a first subset of the nano-elements configured to include the predetermined first optical resonance frequency, and a second subset of the nano-elements configured to include the predetermined second optical resonance frequency. In Example 3, the subject matter of Example 1 or 2 can optionally include that the nano-elements of the first subset are arranged in a first distance respectively adjacent to each other. The nano-elements of the second subset are arranged in 2023P00492 - 20 – second distances respectively adjacent to each other. The second distance is different from the first distance. In Example 4, the subject matter of any one of Examples 1 to 3 can optionally include that the nano-elements of the first subset include a first shape and the nano-elements of the second subset include a second shape. The second shape is different from the first shape. In Example 5, the subject matter of any one of Examples 1 to 4 can optionally include that the nano-elements of the first subset have a first lateral extension and the nano-elements of the second subset have a second lateral extension. The second lateral extension is different from the first lateral extension. In Example 6, the subject matter of any one of Examples 1 to 5 can optionally include that the nano-elements of the first subset have a first tapering angle and the nano-elements of the second subset have second tapering angle. The second tapering angle is different from the first tapering angle. In Example 7, the subject matter of any one of Examples 1 to 6 can optionally include that the nano-elements of the first subset have a first height and the nano-elements of the second subset have second height. The second height is different from the first height. In Example 8, the subject matter of any one of Examples 1 to 7 can optionally include that the plurality of the nano-elements are arranged in a regular pattern. In Example 9, the subject matter of any one of Examples 1 to 8 can optionally include that the arrangement of the arrangement position correspond to a regular grid of positions, wherein each arrangement position corresponds to a grid position. In Example 10, the subject matter of Example 9 can optionally include that the regular grid is any one of a monoclinic grid, an orthorhombic grid, a tetragonal grid and a hexagonal grid. 2023P00492 - 21 – In Example 11, the subject matter of any one of Examples 1 to 10 can optionally include that any of the first subset and second subset of the plurality of nano-elements include ellipsoidal pillar shaped nano-elements including a first axis and a second axis orthogonal to the first axis. The extension of the ellipsoidal pillar in the direction of the second axis is shorter than the extension of the ellipsoidal pillar in the direction of the first axis. In Example 12, the subject matter of any one of Examples 1 to 11 can optionally include that the optical nano-elements of the first subset and the optical nano-elements of the second subset are arranged intertwined on a surface of the substrate. In Example 13, the subject matter of any one of Examples 1 to 12 can optionally include that the plurality of nano-elements further including at least a third subset of nano-elements. The nano-elements of the third subset differ in at least one characteristic from the nano-elements of the first subset and the second subset such that the third subset of nano-elements includes a third optical resonance. In Example 14, the subject matter of Example 13 can optionally include that the nano-elements of the third subset differ in at least one characteristic according to any one of a distance between adjacent optical nano-elements of the subset, a lateral extension of the optical nano-elements of the subset, a height of the optical nano-elements of the subset, a shape of optical nano-elements of the subset, and a tapering angle of the optical nano-elements of the subset. In Example 15, the subject matter of any one of Examples 1 to 14 can optionally include that the nano-elements of the first subset are spaced apart from the nano-elements of the second subset such that the first subset of nano-elements is laterally optically decoupled from the second subset of nano-elements. 2023P00492 - 22 – In Example 16, the subject matter of any one of Examples 1 to 15 can optionally include that the substrate is an optically transparent substrate. In Example 17, the subject matter of any one of Examples 1 to 16 can optionally include that the nano-elements of the first subset are pillars on the substrate, and the nano-elements of the second subset are grooves on the substrate. Example 18 is an optical device, including an optical component having nanostructures and a test structure arranged on a shared substrate. The test structure is configured according to any one of Examples 1 to 17. In Example 19, the subject matter of Example 18 can optionally include that the optical device includes at least a first optical component and a second optical component arranged on a shared substrate, wherein the substrate includes a separation region configured to separate the first optical component and the second optical component from each other. The test structure is arranged in the separation region. In Example 20, the subject matter of Example 18 or 19 can optionally include that the optical component includes a foot print and wherein the test structure is arranged within the foot print of the optical component. In Example 21, the subject matter of any one of Examples 18 to 19 can optionally include that the optical component includes a foot print and wherein the test structure is arranged adjacent to the foot print of the optical component. In Example 22, the subject matter of any one of Examples 18 to 19 can optionally include that the substrate includes a bowed shape. In Example 24, the subject matter of any one of Examples 18 to 23 can optionally include that the optical component is any one of a virtual reality glass or augmented reality glass. 2023P00492 - 23 – Example 25 is a method for manufacturing a component having nanostructures. The method includes forming the nanostructures of the component and a test structure on a shared substrate using at least one shared manufacturing tool. The test structure may be configured according to any one of the above- mentioned Examples. The method may further include determining an optical spectrum of the test structure, wherein the optical spectrum includes at least a first optical resonance corresponding to the first subset of nano-elements of the test structure, and a second optical resonance corresponding to the second subset of nano-elements of the test structure. The method may further include determining a manufacturing tolerance of the at least one shared manufacturing tools based on the determined optical spectrum. In case the determined manufacturing tolerance exceeds a predetermined threshold value, the method may include adjusting at least one parameter of the at least one shared manufacturing tool. In Example 26, the subject matter of Example 25 can optionally include that the nanostructures of the component and the test structure are formed at least in part in parallel. The method may further include any feature as described for the device above. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any example or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other examples or designs. The words “plurality” and “multiple” in the description or the claims expressly refer to a quantity greater than one. The terms “group (of)”, “set [of]”, “collection (of)”, “series (of)”, “sequence (of)”, “grouping (of)”, etc., and the like in the description or in the claims refer to a quantity equal to or greater than one, i.e. one or more. Any term expressed in plural form that does not expressly state “plurality” or 2023P00492 - 24 – “multiple” likewise refers to a quantity equal to or greater than one. The term “connected” can be understood in the sense of a (e.g. mechanical, optical and / or electrical), e.g. direct or indirect, connection and / or interaction. For example, several elements can be connected together mechanically such that they are physically retained (e.g., a plug connected to a socket) and electrically such that they have an electrically conductive path (e.g., signal paths exist along a communicative chain). While the above descriptions and connected figures may depict optical device components as separate elements, skilled persons will appreciate the various possibilities to combine or integrate discrete optical functions into a single element. Such may include combining two or more components from a single component. Conversely, skilled persons will recognize the possibility to separate a single element into two or more discrete elements, such as splitting a single component into two or more separate component. It is appreciated that implementations of methods detailed herein are exemplary in nature, and are thus understood as capable of being implemented in a corresponding device. Likewise, it is appreciated that implementations of devices detailed herein are understood as capable of being implemented as a corresponding method. It is thus understood that a device corresponding to a method detailed herein may include one or more components configured to perform each aspect of the related method. All acronyms defined in the above description additionally hold in all claims included herein. While the disclosure has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims. 2023P00492 - 25 – The scope of the disclosure is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.

[0002] 2023P00492 - 26 – Reference Numeral List 100 test structure 102-i, 102-N optical nano-element (e.g. pillar) 104 substrate 106, 116 lateral extension of optical nano-element (e.g. diameter of pillar) 108, 110 distance, pitch 112 coating layer 120 grid position 122 center axis of optical nano-element 140-1, 140-2, 140-i, 140-N subsets of nano-elements 150 wavelength 152 relative transmission 154 designated resonance 156 functional relation 160, 162, 164 subsets of nano-elements 142, 144 distance between subset of optical nano-elements 180 light of light source 190 light source a wall angle 900, 900-1, 900-2 optical device 902 optical component 1002 separation region (e.g. dicing line) 1100, 1102, 1104, 1106 method and method steps

Claims

2023P00492 - 27 – CLAIMS 1. A test structure for a component having nanostructures, wherein the test structure and the component share a substrate, wherein the nanostructures of the component and the test structure are formed using at least one shared manufacturing tool, the test structure comprising: a plurality of optical nano-elements on the substrate, wherein each of the optical nano-elements is arranged in an arrangement position; wherein any one of a structure of the optical nano-elements and an arrangement of the arrangement positions are configured such that the plurality of nano-elements comprise at least a predetermined first optical resonance frequency and a predetermined second optical resonance frequency; wherein the plurality of the nano-elements comprises a first subset of the nano-elements configured to comprise the predetermined first optical resonance frequency, and a second subset of the nano-elements configured to comprise the predetermined second optical resonance frequency.

2. The test structure of claim 1, wherein the nano-elements of the first subset are arranged in a first distance respectively adjacent to each other; wherein the nano-elements of the second subset are arranged in second distances respectively adjacent to each other, wherein the second distance is different from the first distance.

3. The test structure of any one of claims 1 to 2, wherein the nano-elements of the first subset comprise a first shape and the nano-elements of the second subset comprise a second shape, wherein the second shape is different from the first shape.

4. The test structure of any one of claims 1 to 3, wherein the nano-elements of the first subset have a first lateral extension and the nano-elements of the second2023P00492 - 28 – subset have a second lateral extension, wherein the second lateral extension is different from the first lateral extension.

5. The test structure of any one of claims 1 to 4, wherein the nano-elements of the first subset have a first tapering angle and the nano-elements of the second subset have second tapering angle, wherein the second tapering angle is different from the first tapering angle.

6. The test structure of any one of claims 1 to 5, wherein the nano-elements of the first subset have a first height and the nano-elements of the second subset have second height, wherein the second height is different from the first height.

7. The test structure of any one of claims 1 to 6, wherein the plurality of the nano-elements are arranged in a regular pattern.

8. The test structure of any one of claims 1 to 7, wherein the optical nano-elements of the first subset and the optical nano-elements of the second subset are arranged intertwined on a surface of the substrate.

9. The test structure of any one of claims 1 to 8, the plurality of nano-elements further comprising at least a third subset of nano-elements, wherein the nano-elements of the third subset differ in at least one characteristic from the nano-elements of the first subset and the second subset such that the third subset of nano-elements comprises a third optical resonance.

10. The test structure of claim 9, wherein the nano-elements of the third subset differ in at least one characteristic according to any one of a distance between adjacent optical nano-elements of the subset, a lateral extension of the optical nano-elements of the subset, a height of the optical nano-elements of the subset, a shape of optical2023P00492 - 29 – nano-elements of the subset, and a tapering angle of the optical nano-elements of the subset.

11. The test structure of any one of claims 1 to 10, wherein the nano-elements of the first subset are spaced apart from the nano-elements of the second subset such that the first subset of nano-elements is laterally optically decoupled from the second subset of nano-elements.

12. The test structure of any one of claims 1 to 11, wherein the substrate is an optically transparent substrate.

13. An optical device, comprising: a test structure and an optical component having nanostructures arranged on a shared substrate, wherein the test structure is configured according to any one of claims 1 to 12.

14. The optical device of claim 13, wherein the optical device comprises at least a first optical component and a second optical component arranged on a shared substrate, wherein the substrate comprises a separation region configured to separate the first optical component and the second optical component from each other, wherein the test structure is arranged in the separation region.

15. The optical device of claim 13, wherein the optical component comprises a foot print and wherein the test structure is arranged within the foot print of the optical component.

16. The optical device of claim 13, wherein the optical component comprises a foot print and wherein the test structure is arranged adjacent to the foot print of the optical component.

17. The optical device of any one of claims 13 to 16, wherein the substrate comprises a bowed shape.2023P00492 - 30 – 18. The optical device of any one of claims 13 to 17, wherein the optical component is any one of a virtual reality glass or augmented reality glass.

19. A method for manufacturing a component having nanostructures, the method comprising: forming the nanostructures of the component and a test structure on a shared substrate using at least one shared manufacturing tool; wherein the test structure is configured according to any one of claims 1 to 12; determine an optical spectrum of the test structure, wherein the optical spectrum comprises at least a first optical resonance corresponding to the first subset of nano-elements of the test structure, and a second optical resonance corresponding to the second subset of nano- elements of the test structure; determine a manufacturing tolerance of the at least one shared manufacturing tool based on the determined optical spectrum; and in case the determined manufacturing tolerance exceeds a predetermined threshold value, adjust at least one parameter of the at least one shared manufacturing tool.

20. The method of claim 19, wherein the nanostructures of the component and the test structure are formed at least in part in parallel.

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