SPECIFICATION - AMBIENT LIGHT SENSOR

Abstract

AMBIENT LIGHT SENSOR The present invention relates to an ambient light sensor (10A) comprising a substrate (100), a metasurface (110) disposed on the substrate (100), and an aperture layer (116) disposed on the substrate (100). The metasurface (110) comprises a plurality of nanostructures (112) and a filler layer (114) laterally surrounding the plurality of nanostructures (112). The aperture layer (116) laterally separates the metasurface (110) into a plurality of sub-metagroups (110A, 110B, 110C, 110D, 110E). Figure to be published with the abbreviation: Figure 1A

Description

Title of the invention: AMBIENT LIGHT SENSOR technical field

[0001] The present invention relates to an ambient light sensor (ALS), and in particular to the metasurface of an ambient light sensor. Description of the associated prior art

[0002] Electronic devices such as laptops, cell phones, and other equipment are sometimes equipped with light sensors. For example, ambient light sensors may be incorporated into a device to provide the necessary information about surrounding lighting conditions. Optical readings from the ambient light sensors can be used to control device settings. For example, if bright daylight conditions are detected, the electronic device can increase the display brightness to compensate. In some configurations, ambient light sensors are implemented to collect information about the colors of the ambient light (such as the spectrum). The colors of a displayed image can be adjusted based on the ambient light colors.

[0003] To collect optical readings of different colors, ambient light sensors can include multispectral bandpass filters. Each multispectral bandpass filter can transmit a specific wavelength (or color) of ambient light, while other unwanted colors (including infrared from sunlight) are either absorbed or reflected in the opposite direction by the multispectral bandpass filters, thus increasing the color distinction capability. Since the multispectral bandpass filters are different from one another, they must be modeled separately. Depending on the number of multispectral bandpass filters designed, there may be many modeling processing cycles, resulting in longer cycle times and higher manufacturing costs.Therefore, these and other related problems must be addressed during the design and manufacture of the ambient light sensor.

[0004] The present invention relates to an ambient light sensor comprising a substrate, a metasurface disposed on the substrate, and an aperture layer disposed on the substrate. The metasurface comprises a plurality of nanostructures and a filling layer laterally surrounding the plurality of nanostructures. The aperture layer laterally separates the metasurface into a plurality of sub-metagroups.

[0005] According to one embodiment, the aperture layer comprises a black photoresin, a dielectric material or metals, the aperture layer being arranged horizontally between the plurality of sub-metagroups, or the opening layer being arranged above the metasurface.

[0006] According to one embodiment, the ambient light sensor further comprises a plurality of detection parts integrated into the substrate, the plurality of sub-metagroups being arranged in correspondence with the plurality of detection parts, respectively.

[0007] According to one embodiment, each of the plurality of nanostructures has a circular shape, a rectangular shape or a hexagonal shape in top view, a thickness of the filling layer being equal to a thickness of the plurality of nanostructures, or the thickness of the filling layer being greater than the thickness of the plurality of nanostructures.

[0008] According to one embodiment, a refractive index of the plurality of nanostructures is less than 1.4, a refractive index of the filling layer being less than the refractive index of the plurality of nanostructures, the filling layer is air.

[0009] According to one embodiment, a first transparent conductive film (TCF) is disposed between the substrate and the metasurface, the first transparent conductive film being a transparent conductive oxide (TCO), the transparent conductive oxide comprising indium tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide (ZnO) or aluminum-doped zinc oxide (AZO).

[0010] According to one embodiment, the ambient light sensor further comprises a diffusion structure disposed on the metasurface and the aperture layer; and a spacing layer disposed between the metasurface and the diffusion structure.

[0011] According to one embodiment, the diffusion structure comprises a layer of glue covering the metasurface and the aperture layer; and dispersed particles arranged in the glue layer.

[0012] According to one embodiment, the diffusion structure comprises a first layer of glue covering the metasurface and the aperture layer; a lens layer disposed on the first layer of glue, the lens layer having a curved surface; and a second layer of glue covering the lens layer.

[0013] According to one embodiment, the ambient light sensor further comprises a lower glass layer disposed between the first glue layer and the lens layer; a second transparent conductive film disposed between the first glue layer and the lower glass layer; and an upper glass layer disposed above the second glue layer.

[0014] The detailed description that follows will allow for a better understanding of the invention when read in conjunction with the accompanying figures. It should be noted that, in accordance with common industry practice, various features are not drawn to scale. In reality, the dimensions of the various characteristics can be arbitrarily increased or decreased for the sake of clarity in the discussion.

[0015] [Fig.1A] is a cross-sectional view of an ambient light sensor with a particular design, according to certain embodiments of the present invention.

[0016] [Fig.1B] is a cross-sectional view of an ambient light sensor with a particular design, according to certain embodiments of the present invention.

[0017] [Fig.lC] is a cross-sectional view of an ambient light sensor with a particular design, according to certain embodiments of the present invention.

[0018] [Fig.2A] is a cross-sectional view of an ambient light sensor with a particular design, according to other embodiments of the present invention.

[0019] [Fig.2B] is a cross-sectional view of an ambient light sensor with a particular design, according to other embodiments of the present invention.

[0020] [Fig.2C] is a cross-sectional view of an ambient light sensor with a particular design, according to other embodiments of the present invention.

[0021] [Fig.3A] is a cross-sectional view of an ambient light sensor with a particular design, according to certain embodiments of the present invention.

[0022] [Fig.3B] is a cross-sectional view of an ambient light sensor with a particular design, according to certain embodiments of the present invention.

[0023] [Fig.3C] is a cross-sectional view of an ambient light sensor with a particular design, according to certain embodiments of the present invention.

[0024] [Fig.4A] is a cross-sectional view of an ambient light sensor with a particular design, according to other embodiments of the present invention.

[0025] [Fig.4B] is a cross-sectional view of an ambient light sensor with a particular design, according to other embodiments of the present invention.

[0026] [Fig.4C] is a cross-sectional view of an ambient light sensor with a particular design, according to other embodiments of the present invention.

[0027] The following invention provides numerous different embodiments, or examples, for implementing the various features of the object presented. Specific examples of components and arrangements are described below to simplify the present invention. Of course, these are only examples and are not limiting. For example, a first feature formed on a second feature in the following description may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact.

[0028] It is understood that additional steps may be implemented before, during or after the illustrated processes, and that certain steps may be replaced or omitted in other embodiments of the illustrated processes.

[0029] Furthermore, spatially relative terms, such as "under", "below", "lower", "on", "above", "upper", and the like, may be used here to facilitate the description of the relationship of one element or feature to other elements or features as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation shown in the figures. The device may be oriented differently (rotated 90 degrees or in other orientations), and the spatially relative descriptors used here may also be interpreted accordingly.

[0030] In the present invention, the terms "approximately," "about," and "significantly" generally mean ±20% of the stated value, more generally ±10% of the stated value, more generally ±5% of the stated value, more generally ±3% of the stated value, more generally ±2% of the stated value, more generally ±1% of the stated value, and still more generally ±0.5% of the stated value. The stated value in the present invention is an approximate value. In other words, in the absence of a specific description of the terms "approximately," "about," and "significantly," the stated value includes the meaning of "about," "about," or "significantly."

[0031] Unless otherwise defined, all terms (including technical and scientific terms) used herein shall have the same meaning as that commonly understood by a person with ordinary competence in the art to which the present invention belongs. It is understood that terms such as those defined in commonly used dictionaries shall be interpreted as having a meaning consistent with their meaning in the context of the prior art and shall not be interpreted in an idealized or overly formal sense, unless expressly defined as such in embodiments of the present invention.

[0032] This description may repeat reference numbers and / or letters in the following embodiments. This repetition is for the sake of simplicity and clarity and does not in itself imply a relationship between the various embodiments and / or configurations discussed.

[0033] In nature, ambient light can be a combination of various colors across all wavelength ranges. In a multispectral ambient light sensor, multiple bandpass filters are implemented to detect the various colors of ambient light. In some embodiments, the multiple bandpass filters can be designed to have a specific full width at half maximum (FWHM), specific transmittance, specific center wavelength (CWL), and other specific parameters. For example, the FWHM is the width of a spectral curve measured between the two points on the transmittance axis that correspond to half the maximum amplitude. Transmittance is the fraction of ambient light at a particular wavelength that the bandpass filters transmit. The center wavelength is the weighted average of wavelengths across the spectrum. The aforementioned parameters can determine the overall optical performance of the ambient light sensor.

[0034] The present invention incorporates a metasurface in the ambient light sensor to replace the multiple conventional bandpass filters. The metasurface comprises nanostructures (such as nanopoles or pillars) that generate the phase modulation necessary for different wavelengths (or colors). When the nanostructures are arranged across the metasurface, different wavelengths (or colors) of ambient light can be separated, which can serve as a bandpass filter. By designing the dimensions and spacing of the nanostructures using an algorithm, the colors of ambient light can be transmitted through the designated areas, respectively.

[0035] Since multiple conventional bandpass filters must be modeled separately, the cycle time can be prolonged, while the manufacturing cost can increase. The modeling can be a processing cycle that includes deposition, photolithography, and etching. Each processing cycle can be used only to form a single bandpass filter. Since the previously formed structure can create a step height for subsequent processing cycles, it would be more difficult to withstand the following processing cycles. For example, poor coating, stripping, or other cosmetic defects can be easily induced. The inventor discovered that implementing a metasurface can simplify overall production and provide the same function as multiple bandpass filters.Furthermore, the metasurface can be modeled in a single processing cycle, thus reducing the occurrence of cosmetic defects. It should be noted that even if the multispectral configuration of the ambient light sensor were to be expanded to account for additional colors, the metasurface can be designed accordingly, while still being modeled in a single processing cycle. Consequently, the metasurface can be manufactured more quickly and at a lower cost.

[0036] Figures 1A-1C are cross-sectional views of ambient light sensors 10A, 10B and 10C of various designs, according to certain embodiments of the present invention. According to certain embodiments of the present invention, the ambient light sensors 10A, 10B and 10C may comprise a substrate 100, a plurality of sensing parts 104, a metasurface 110, an aperture layer 116, an adhesive layer 130 and dispersed particles 132. The metasurface 110 may comprise a plurality of nanostructures 112 and a filler layer 114. In addition, the aperture layer 116 may laterally separate the metasurface 110 into a sub-metagroup 110A, a sub-metagroup 110B, a sub-metagroup HOC, a sub-metagroup 110D and a sub-metagroup 110E.

[0037] With reference to [Fig. 1A], the substrate 100 may be, for example, a wafer or a chip, but the present invention is not limited to this. In some embodiments, the substrate 100 may be a semiconductor substrate, for example, a silicon substrate.Furthermore, in some embodiments, the semiconductor substrate may also be an elemental semiconductor (such as germanium), a compound semiconductor (such as gallium nitride (GaN), silicon carbide (SiC), gallium arsenide (GaAs), gallium phosphide (GaP), indium phosphide (InP), indium arsenide (InAs), or indium antimonide (InSb)), an alloy semiconductor (such as a silicon-germanium alloy (SiGe), a gallium-arsenide-phosphide alloy (GaAsP), an aluminum-indium-arsenide alloy (AlInAs), an aluminum-gallium-arsenide alloy (AlGaAs), a gallium-indium-arsenide alloy (GalnAs), or a gallium-indium-phosphide alloy). (GalnP) or a gallium-indium-arsenide-phosphide alloy (GalnAsP)), or a combination thereof.In some embodiments, the substrate 100 may be a photoelectric conversion substrate, such as a silicon substrate or an organic photoelectric conversion layer.

[0038] In other embodiments, the substrate 100 may also be a semiconductor-on-insulator (SOI) substrate. The semiconductor-on-insulator substrate may comprise a base plate, a buried oxide layer disposed on the base plate, and a semiconductor layer disposed on the buried oxide layer. Furthermore, the substrate 100 may be an n-type or p-type conductive type.

[0039] In some embodiments, the substrate 100 may comprise various p-type doped regions and / or n-type doped regions (not shown) formed, for example, by an ion implantation and / or diffusion process. In some embodiments, transistors, photodiodes, or analogs may be formed at the active regions, which are defined by an isolation structure.

[0040] In certain embodiments, the insulation structure can be integrated into the substrate 100 to define active regions and to electrically isolate elements of an active region within or above the substrate 100, but the present invention is not limited to this. The insulation structure may be a deep trench insulation structure (DTI), a shallow trench insulation structure (STI), and a local silicon oxidation structure (LOCOS). In some embodiments, the formation of the insulation structure may include, for example, the formation of an insulating layer on the substrate 100. Through a suitable photolithography process and a suitable etching process, trenches may be formed by extending into the substrate 100.

[0041] Next, a coating of nitrogen-rich materials (such as silicon oxynitride (SiON)) can grow conformally along the trenches. After this, insulating materials (such as silicon dioxide (SiO2), silicon nitride (SiN), or silicon oxynitride) can be introduced into the trenches by a suitable deposition process. An annealing process can then be performed on the insulating materials in the trenches, followed by a planarization process, such as chemical mechanical polishing (CMP), on the substrate 100 to remove excess insulating materials, so that the insulating materials in the trenches are level with the top surface of the substrate 100.

[0042] With further reference to [Fig. 1A], the plurality of detection parts 104 are integrated into the substrate 100. In some embodiments, the plurality of detection parts 104 are photodiodes. Each of the plurality of detection parts 104 is configured to detect ambient light and to generate an intensity signal as a function of the intensity of the ambient light it detects. The electrical signal is formed by the intensity signals and can be digital data or readings of the quantity of electrons.

[0043] With reference to [Fig. 1 A], the metasurface 110 can be arranged on the substrate 100. In some embodiments, the submetagroup 110A, submetagroup 110B, submetagroup HOC, submetagroup 110D and submetagroup 110E can correspond respectively to the sensing portions 104 inside the substrate 100 of the ambient light sensor 10A. According to some embodiments of the present invention, the metasurface 110 can function as a spectrum-selective layer, which can separate different wavelengths (or colors) of ambient light using diffraction or refraction characteristics.Therefore, each of submetagroup 110A, submetagroup 110B, submetagroup HOC, submetagroup 110D and submetagroup 110E can be designed to allow only the transmission of the desired color, while unwanted colors can be absorbed or reflected on the opposite side by submetagroup 110A, submetagroup 110B, submetagroup HOC, submetagroup 110D and submetagroup 110E.

[0044] In certain embodiments, each of the submetagroup 110A, submetagroup 110B, submetagroup HOC, submetagroup 110D, and submetagroup 110E transmits a predetermined range of ambient light wavelengths. For example, red light has wavelengths in the range of 620 to 750 nm to be transmitted to the corresponding sensing parts 104, green light has wavelengths in the range of 495 to 570 nm to be transmitted to the corresponding sensing parts 104, and blue light has wavelengths in the range of 450 to 495 nm to be transmitted to the corresponding sensing parts 104.In a specific embodiment of the present invention, submetagroup 110A, submetagroup 110B, submetagroup 110C, submetagroup 110D and submetagroup 110E can transmit the colours red, yellow, green, blue and magenta, respectively, or a more specific colour wavelength, including far-infrared (FIR) and short-wavelength infrared (SWIR).

[0045] As previously stated, the metasurface 110 may comprise the plurality of nanostructures 112 and the filler layer 114. In some embodiments, the filler layer 114 may laterally surround the plurality of nanostructures 112. The thickness of the metasurface 110 is between 10 nm and 10 µm. In some embodiments, the filler layer 114 and the plurality of nanostructures 112 may have the same thickness. In other embodiments, the thickness of the filler layer 114 and that of the plurality of nanostructures 112 may vary, depending on the application and design requirements. Each of the plurality of nanostructures 112 has a circular, rectangular, hexagonal, or any other symmetrical or asymmetrical shape when viewed from above. The dimension of each of the plurality of nanostructures 112 in top view can be between 2 nm and 2000 nm.According to certain embodiments of the present invention, the refractive index of the filler layer 114 is lower than the refractive index of the plurality of nanostructures 112. The refractive index of the filler layer 114 can be between 1.0 and 3.0. The refractive index of the plurality of nanostructures 112 can be greater than 1.4, for example between 1.4 and 4.0. In some embodiments, the filler layer 114 can be air, which has a refractive index of 1.

[0046] Materials of the plurality of nanostructures 112 may include conductive or dielectric materials, such as aluminum oxide (Al₂O₃), niobium(V) oxide (Nb₂O₅), gallium nitride, tantalum pentoxide (Ta₂O₅), titanium nitride (TiN), titanium dioxide (TiO₂), silicon nitride, silane (SiH₄), silicon dioxide (SiO₂), etc., or a combination thereof. of the filling layer 114 may include polymers or dielectric materials, such as silicon oxide, silicon dioxide (SiO2), polyethylene terephthalate (PET) resins, polycarbonate (PC) resins, polyimide (PI) resins, polymethyl methacrylates (PMMA), polystyrene resins, polyethersulfone (PES) resins, polythiophene (PT) resins, phenol novolac (PN), spin glass resin (SOG), spin dielectric (SOD), etc., or a combination thereof.

[0047] The metasurface 110 can be formed by modeling the plurality of nanostructures 112, followed by filling the space between the plurality of nanostructures 112 with the filler layer 114. Initially, a layer of material can be deposited onto the substrate 100 using a suitable deposition process, such as chemical vapor deposition (CVD), high-density plasma chemical vapor deposition (HDP-CVD), plasma-assisted chemical vapor deposition (PECVD), fluidizable chemical vapor deposition (FCVD), subatmospheric chemical vapor deposition (SACVD), physical vapor deposition (PVD), atomic layer deposition (ALD), etc., or a combination thereof. Subsequently, a hard mask layer (not shown) is coated onto the material layer. In some embodiments, the hard mask layer can be a photosensitive resin.A photolithography process is performed to model the hard mask layer, which may include resist coating, soft firing, exposure, post-exposure firing, development, etc., or a combination thereof. Following this, an etching process (such as dry etching, wet etching, etc., or a combination thereof) is performed on the material layer using the modeled hard mask. After the etching process, a portion of the material layer is removed from the substrate 100, creating multiple openings. As mentioned previously, these openings will then be filled with the filler layer 114.

[0048] With further reference to [Fig. 1A], the aperture layer 116 is arranged horizontally between neighboring submetagroups. For example, the aperture layer 116 can define the boundary of submetagroup 110A, submetagroup 110B, submetagroup HOC, submetagroup 110D, and submetagroup 110E. According to certain embodiments of the present invention, when ambient light is transmitted and separated through submetagroup 110A, submetagroup 110B, submetagroup HOC, submetagroup 110D, or submetagroup 110E, the aperture layer 116 can isolate the light ray within the specific submetagroup to serve as a light-blocking function.

[0049] In a conventional design, once the multiple bandpass filters have been arranged and placed side by side on the substrate, an aperture layer is deposited in a consistent manner based on the collective structure of the multiple bandpass filters. The aperture layer can then be modeled to expose each of the underlying multiple bandpass filters. As mentioned earlier, the multiple bandpass filters must be modeled separately, and the structure formed previously can create a step height that poses a greater challenge for subsequent processing cycles. Ideally, the junction interface between neighboring multiple bandpass filters should be vertical. However, due to the processing variation caused by the step height problem, adjacent multiple bandpass filters may not be precisely aligned, resulting in some junction interfaces being tilted. When ambient light enters in the normal direction, the tilted interface can generate scattered light rays of mixed colors, which are considered optical noise.The normal direction is perpendicular to the substrate surface. If these scattered light rays of mixed colors are received by the sensing parts, unwanted signals may be converted. For this reason, only the central parts of the multiple bandpass filters, in top view, are exposed. The area near the junction interfaces may remain covered by the aperture layer; it is therefore known as an ineffective region. The ineffective region at the junction interfaces can have dimensions in the range of 20 µm to 25 µm in top view. For the ineffective region at the edge of the collective structure of the multiple bandpass filters, its dimensions can be between 10 µm and 15 µm in top view.

[0050] According to certain embodiments of the present invention, the metasurface 110 can be used to replace multiple conventional bandpass filters. Since the metasurface 110 can be modeled during a single processing cycle, the placement design of each submetagroup has greater flexibility. The step height problem during modeling and the misalignment problem between multiple neighboring bandpass filters can both be eliminated. The size of the aperture layer 116 between neighboring submetagroups (or the ineffective region of the junction interfaces) can be reduced to approximately 10 µm in top view.It is important to understand that, even if the sub-metagroups are not placed next to each other, the presence of the aperture layer 116 is still necessary to ensure that neighboring sub-metagroups are spaced out in such a way as to avoid any undesirable interaction effects (e.g., diffraction behavior).

[0051] The thickness of the aperture layer 116 can be the same as that of the metasurface 110. Materials of the aperture layer 116 can include a black photosensitive resin, dielectric materials, opaque metals (such as tungsten (W), aluminum (Al)), opaque metal nitride (such as nitride titanium), opaque metal oxide (such as titanium oxide (TiO)), other suitable materials, or a combination thereof, but the present invention is not limited to these. The aperture layer 116 can be formed by any suitable deposition process, such as a spin coating process, chemical vapor deposition, physical vapor deposition (PVD), atomic layer deposition (ALD), other suitable processes, or a combination thereof.

[0052] With reference to [Fig. 1 A], the adhesive layer 130 can be disposed on the metasurface 110 and the aperture layer 116. In some embodiments, the adhesive layer 130 can cover the metasurface 110 and the aperture layer 116. According to some embodiments of the present invention, the adhesive layer 130 can provide the necessary support for ambient light (in particular, inclined light rays) to diffuse into a more normal distribution spectrum. Furthermore, the adhesive layer 130 can provide mechanical protection for the underlying structures, as well as adhesion to any underlying component. The refractive index of the adhesive layer 130 is between 1.0 and 3.0. The thickness of the adhesive layer 130 can be between 100 nm and 100 µm.

[0053] The adhesive layer 130 may be a dielectric material comprising, for example, silicon oxide, silicon nitride, silicon carbide, silicon carbonitride (SiCN), silicon oxynitride, silicon oxynitrocarbide (SiOxNyCi.xy, where x and y are in a range from 0 to 1), tetraethyl orthosilicate (TEOS), undoped silicate glass, or doped silicon oxide (such as boron-doped phosphosilicate glass (BPSG), fused silica glass (FSG), phosphosilicate glass (PSG), boron-doped silicon glass (BSG) or analogous), low k dielectric materials, transparent organic materials, etc., or a combination thereof, but the present invention is not limited to these. The formation of the 130 adhesive layer may include any appropriate deposition process mentioned above.After that, a planarization process, such as chemical mechanical polishing, can be carried out to form a planarized top surface.

[0054] With further reference to [Fig. 1A], the dispersed particles 132 can be randomly distributed within the adhesive layer 130. In some embodiments, the adhesive layer 130 and the dispersed particles 132 can be collectively referred to as the diffusion structure for downstream manufacturing. In some embodiments, the diffusion structure can be applied to collect ambient light from a variety of angles for reception by the plurality of sensing parts 104. According to some embodiments of the present invention, the dispersed particles 132 can be designed to interfere with Optical propagation allows the incoming direction of inclined light rays to be adjusted close to the normal direction. In other words, the dispersed particles 132 can improve off-axis ambient light reception, and from the perspective of the ambient light sensor 10A, the ambient light source can be detected more uniformly. Consequently, the optical readings of the ambient light sensor 10A can be less dependent on the relative orientations between the sensor and the ambient light source.

[0055] The dispersed particles 132 may have a round shape, an oval shape, or any other suitable geometric shape in cross-section. The size of each of the dispersed particles 132 may be between 1 nm and 10 sqm. The dispersed particle materials 132 may include transparent conductive materials, such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide (ZnO), tin oxide (SnO), indium zinc oxide (IZO), indium-gallium-zinc oxide (IGZO), indium-tin-zinc oxide (ITZO), antimony-tin oxide (ATO), aluminum-doped zinc oxide (AZO), titanium dioxide, tantalum pentoxide, niobium(V) oxide, silicon nitride, gallium nitride, aluminum nitride (AIN), etc., or a combination thereof. The dispersed particles 132 may be incorporated into the adhesive layer 130 by casting, extrusion, injection molding, lamination, etc., or a combination of these.

[0056] With reference to [Fig. 1B], the cross-sectional view of the ambient light sensor 10B is shown. Compared to [Fig. 1A], a spacer layer 120 can be arranged between the metasurface 110 and the scattering structure (e.g., the glue layer 130 and the scattered particles 132). The characteristics of the substrate 100, the plurality of sensing parts 104, the metasurface 110, the aperture layer 116, the glue layer 130, and the scattered particles 132 are similar to those illustrated in [Fig. 1A], and the details are not described again here to avoid repetition.

[0057] With further reference to [Fig. 1B], the spacer layer 120 can separate the metasurface 110 and the scattering structure (e.g., the glue layer 130 and the scattered particles 132), depending on the application or design requirements. In some embodiments, the spacer layer 120 can provide the necessary pathways for the scattered light rays to penetrate the metasurface 110. According to some embodiments of the present invention, the different wavelengths (or colors) of ambient light can be separated by the metasurface 110, such that each of the submetagroup 110A, submetagroup 110B, submetagroup HOC, submetagroup 110D, and submetagroup 110E can allow only the transmission of the color desired. Furthermore, the 110 metasurface can be modeled in a single processing cycle, thus reducing the occurrence of cosmetic defects. In other words, the 110 metasurface can be manufactured faster and at a lower cost.

[0058] The thickness of the spacer layer 120 can be between 100 nm and 50 µm. The materials of the spacer layer 120 can be similar to those of the filler layer 114, and the details are not described again here to avoid repetition. The spacer layer 120 can be formed by any suitable deposition process mentioned above. In other embodiments, the filler layer 114 can be deposited so as to extend beyond the plurality of nanostructures 112. For example, the filler layer 114 can completely cover the plurality of nanostructures 112, such that the upper surface of the filler layer 114 is higher than the upper surface of the plurality of nanostructures 112. Under these conditions, the part of the filler layer 114 located above the upper surface of the plurality of nanostructures 112 can be called a spacing layer 120.Therefore, the materials of the filling layer 114 and the materials of the spacing layer 120 can be substantially identical.

[0059] With reference to [Fig. IC], the cross-sectional view of the ambient light sensor 10C is shown. Compared to [Fig. 1 A], the aperture layer 116 can be arranged above the metasurface 110, and not within it. The characteristics of the substrate 100, the plurality of sensing parts 104, the metasurface 110, the aperture layer 116, the adhesive layer 130, and the dispersed particles 132 are similar to those illustrated in [Fig. 1 A], and the details are not described again here to avoid repetition.

[0060] Still with reference to [Fig.1C], the metasurface 110 and the opening layer 116 are placed at different levels, depending on the application or design requirements. More specifically, the aperture layer 116 can be disposed directly above the filling layer 114. In some embodiments, the aperture layer 116 can be disposed inside the adhesive layer 130 to channel the scattered light rays before they are transmitted through the metasurface 110. According to some embodiments of the present invention, the different wavelengths (or colors) of ambient light can be separated by the metasurface 110, such that each of the sub-metagroup 110A, sub-metagroup 110B, sub-metagroup HOC, sub-metagroup 110D and sub-metagroup 110E can allow only the transmission of the desired color.Furthermore, the 110 metasurface can be modeled in a single processing cycle, thus reducing the occurrence of cosmetic defects. In other words, the 110 metasurface can be manufactured faster and at a lower cost.

[0061] Figures 2A-2C are cross-sectional views of ambient light sensors 20A, 20B, and 20C with various designs, according to other embodiments of the present invention. In some embodiments, additional film layers may be arranged between the substrate 100 and the metasurface 110, depending on the application or design requirements. The characteristics of the substrate 100, the plurality of sensing parts 104, the metasurface 110, the aperture layer 116, the spacer layer 120, the adhesive layer 130, and the dispersed particles 132 are similar to those illustrated in Figures 1A-1C, and the details are not described again here to avoid repetition.

[0062] With reference to [Fig. 2A], the cross-sectional view of the ambient light sensor 20A is shown. Compared to [Fig. 1A], a first transparent conductive film (TCF) 108 can be disposed between the substrate 100 and the metasurface 110. According to certain embodiments of the present invention, the first transparent conductive film 108 can input or output additional electrical signals to be converted for the plurality of sensing parts 104. According to certain embodiments of the present invention, the different wavelengths (or colors) of ambient light can be separated by the metasurface 110, such that each of the submetagroup 110A, submetagroup 110B, submetagroup HOC, submetagroup 110D, and submetagroup 110E can allow the transmission of only the desired color.Furthermore, the metasurface 110 can be modeled in a single processing cycle, thus reducing the occurrence of cosmetic defects. In other words, the metasurface 110 can be fabricated more quickly and at a lower cost. The thickness of the first transparent conductive film 108 can range from 10 nm to 200 nm. The first transparent conductive film 108 can be a transparent conductive oxide (TCO), which includes indium tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide (ZnO), or aluminum-doped zinc oxide (AZO). The first transparent conductive film 108 can be formed by any suitable deposition process mentioned above.

[0063] With reference to [Fig. 2B], the cross-sectional view of the ambient light sensor 20B is shown. Compared to [Fig. 1B], the first transparent conductive film 108 can be arranged between the substrate 100 and the metasurface 110. The characteristic of the first transparent conductive film 108 is similar to that shown in [Fig. 2A], and the details are not described again here to avoid repetition. According to some embodiments of the present invention, the different wavelengths (or colors) of ambient light can be separated by the metasurface 110, such that each of the submetagroups 110A, 110B, HOC, 110D, and 110E can allow the transmission of only the desired color. Furthermore, the Metasurface 110 can be modeled in a single processing cycle, thus reducing the occurrence of cosmetic defects. In other words, metasurface 110 can be manufactured faster and at a lower cost.

[0064] With reference to [Fig. 2C], the cross-sectional view of the ambient light sensor 20C is shown. Compared to [Fig. 1C], the first transparent conductive film 108 can be arranged between the substrate 100 and the metasurface 110. The characteristics of the first transparent conductive film 108 are similar to those shown in [Fig. 2A], and the details are not described again here to avoid repetition. According to some embodiments of the present invention, the different wavelengths (or colors) of ambient light can be separated by the metasurface 110, such that each of the submetagroups 110A, 110B, HOC, 110D, and 110E can allow the transmission of only the desired color. In addition, the 110 metasurface can be modeled during a single treatment cycle, thus reducing the appearance of cosmetic defects.In other words, the 110 metasurface can be manufactured more quickly and at a lower cost.

[0065] Figures 3A-3C are cross-sectional views of ambient light sensors 30A, 30B, and 30C with various designs, according to certain embodiments of the present invention. In some embodiments, a different diffusion structure may be implemented, depending on the application or design requirements. The characteristics of the substrate 100, the plurality of sensing parts 104, the metasurface 110, the aperture layer 116, and the spacing layer 120 are similar to those illustrated in Figures 1A-1C, and the details are not described again here to avoid repetition.

[0066] With reference to [Fig. 3A], the cross-sectional view of the ambient light sensor 30A is shown. Compared to [Fig. 1A], the diffusion structure having the adhesive layer 130 and the dispersed particles 132 is replaced by a new diffusion structure having an adhesive layer 130, a lower glass layer 140, an adhesive layer 150, a lens layer 152, and an upper glass layer 160. According to certain embodiments of the present invention, the different wavelengths (or colors) of ambient light can be separated by the metasurface 110, such that each of the submetagroup 110A, submetagroup 110B, submetagroup HOC, submetagroup 110D, and submetagroup 110E can allow the transmission of only the desired color. In addition, the 110 metasurface can be modeled during a single treatment cycle, thus reducing the appearance of cosmetic defects.In other words, the 110 metasurface can be manufactured more quickly and at a lower cost.

[0067] With further reference to [Fig. 3A], the adhesive layer 130 can be disposed on the metasurface 110 and the aperture layer 116. The characteristics of the adhesive layer 130 illustrated in [Fig. 3A] are similar to those illustrated in [Fig. 1A], and the details are not described again here to avoid repetition. Instead of incorporating the dispersed particles 132, the lower glass layer 140 can be disposed on the adhesive layer 130. The lower glass layer 140 can serve as a substrate for the production of a lens structure. The thickness of the lower glass layer 140 can be between 150 µm and 700 µm. Materials of the lower glass layer 140 can include polymers, resins, or any other suitable light-transmitting insulating material. The lower glass layer 140 can be formed by any appropriate deposition process mentioned above.

[0068] With reference to [Fig. 3A], the lens layer 152 can be arranged on the lower glass layer 140. In some embodiments, the lens layer 152 has a curved surface, for example, an array of concave lens profiles oriented inward toward the metasurface 110. The array of concave lens profiles can have various radii of curvature. According to some embodiments of the present invention, when ambient light reaches the lens layer 152, the incoming direction of the inclined light rays can be adjusted close to the normal direction. As with the scattered particles 132, the lens layer 152 can improve the reception of off-axis ambient light and, from the perspective of the ambient light sensor 30A, the ambient light source can be detected more uniformly.Therefore, the optical readings of the 30A ambient light sensor may be less dependent on the relative orientation between the 30A ambient light sensor and the ambient light source. The thickness of the 152 lens layer can range from 500 nm to 5 µm. Materials for the 152 lens layer can include tantalum pentoxide, titanium nitride, titanium dioxide, silicon nitride, silane, silicon oxide, resin, etc., or a combination thereof. The 152 lens layer can be composed of organic or inorganic materials, depending on the application or design requirements. The 152 lens layer can be formed by any suitable resin deposition or coating process mentioned above.The lens pattern can be defined directly by lithography or pressed against a mold, which contains a three-dimensional lens pattern with a shape opposite to the desired shape for the lens layer 152. Then, the lens pattern can be transferred onto the deposited film by any suitable etching process.

[0069] With further reference to [Fig. 3A], the adhesive layer 150 can be disposed on the lens layer 152. In some embodiments, the adhesive layer 150 fills the network of concave lens profiles of the lens layer 152. The The characteristics of adhesive layer 150 may be similar to those of adhesive layer 130, and the details are not described again here to avoid repetition. Next, the upper glass layer 160 can be placed on top of adhesive layer 150. The characteristics of the upper glass layer 160 may be similar to those of the lower glass layer 140, and the details are not described again here to avoid repetition. It should be noted that the lower glass layer 140 and the upper glass layer 160 can contain adhesive layer 150 and lens layer 152. Adhesive layers 130 and 150 can adhere to the lower glass layer 140 and the upper glass layer 160, respectively. It should be noted that the lower glass layer 140 and the upper glass layer 160 are optional.For example, the lower glass layer 140, the upper glass layer 160, or both the lower glass layer 140 and the upper glass layer 160 can be eliminated by directly processing the lens layer on the sensor structure. Since the lower glass layer 140 or the upper glass layer 160 is generally relatively thick, omitting the lower glass layer 140 and / or the upper glass layer 160 can significantly reduce the overall size of the 30A ambient light sensor.

[0070] With reference to [Fig. 3B], the cross-sectional view of the ambient light sensor 30B is shown. Compared to [Fig. 1B], the diffusion structure having the adhesive layer 130, the lower glass layer 140, the adhesive layer 150, the lens layer 152, and the upper glass layer 160 can be fabricated on the metasurface 110. The characteristics of the adhesive layer 130, the lower glass layer 140, the adhesive layer 150, the lens layer 152, and the upper glass layer 160 are similar to those illustrated in [Fig. 3A], and the details are not described again here to avoid repetition.According to certain embodiments of the present invention, the different wavelengths (or colors) of ambient light can be separated by the metasurface 110, such that each of the submetagroups 110A, 110B, HOC, 110D, and 110E allows only the transmission of the desired color. Furthermore, the metasurface 110 can be modeled in a single processing cycle, thus reducing the occurrence of cosmetic defects. In other words, the metasurface 110 can be manufactured more quickly and at a lower cost.

[0071] With reference to [Fig. 3C], the cross-sectional view of the ambient light sensor 30C is shown. Compared to [Fig. 1C], the diffusion structure having the adhesive layer 130, the lower glass layer 140, the adhesive layer 150, the lens layer 152, and the upper glass layer 160 can be fabricated on the metasurface 110. The characteristics of the adhesive layer 130, the lower glass layer 140, the adhesive layer 150, the lens layer 152, and the upper glass layer 160 are similar to those illustrated in [Fig. 3A], and the details are not described again here to avoid repetition. According to certain embodiments of the present invention, the different wavelengths (or colors) of ambient light can be separated by the metasurface 110, such that each of the submetagroups 110A, 110B, HOC, 110D, and 110E allows only the transmission of the desired color. Furthermore, the metasurface 110 can be modeled in a single processing cycle, thus reducing the occurrence of cosmetic defects. In other words, the 110 metasurface can be manufactured faster and at a lower cost.

[0072] Figures 4A-4C are cross-sectional views of ambient light sensors 40A, 40B, and 40C with various designs, according to other embodiments of the present invention. In some embodiments, additional film layers may be arranged below and above the metasurface 110, depending on the application or design requirements. The characteristics of the substrate 100, the plurality of sensing parts 104, the metasurface 110, the aperture layer 116, and the spacer layer 120 are similar to those illustrated in Figures 1A-1C, and the details are not described again here to avoid repetition.In addition, the characteristics of the glue layer 130, the lower glass layer 140, the glue layer 150, the lens layer 152 and the upper glass layer 160 are similar to those illustrated in Figures 3A-3C, and the details are not described again here to avoid repetition.

[0073] With reference to [Fig. 4A], the cross-sectional view of the ambient light sensor 40A is shown. Compared to [Fig. 3A], a first transparent conductive film 108 can be arranged between the substrate 100 and the metasurface 110, and a second transparent conductive film 138 can be arranged between the adhesive layer 130 and the lower glass layer 140. The characteristics of the first transparent conductive film 108 shown in [Fig. 4A] are similar to those shown in [Fig. 2A], and the details are not described again here to avoid repetition. The characteristics of the second transparent conductive film 138 are similar to those of the first transparent conductive film 108, and the details are not described again here to avoid repetition.According to certain embodiments of the present invention, the different wavelengths (or colors) of ambient light can be separated by the metasurface 110, such that each of the submetagroups 110A, 110B, HOC, 110D, and 110E allows the transmission of only the desired color. Furthermore, the... Metasurface 110 can be modeled in a single processing cycle, thus reducing the occurrence of cosmetic defects. In other words, metasurface 110 can be manufactured faster and at a lower cost.

[0074] With reference to [Fig. 4B], the cross-sectional view of the ambient light sensor 40B is shown. Compared to [Fig. 3B], the first transparent conductive film 108 can be arranged between the substrate 100 and the metasurface 110, and the second transparent conductive film 138 can be arranged between the adhesive layer 130 and the lower glass layer 140. The characteristics of the first transparent conductive film 108 and the second transparent conductive film 138 are similar to those illustrated in [Fig. 4A], and the details are not described again here to avoid repetition. According to certain embodiments of the present invention, the different wavelengths (or colors) of ambient light can be separated by the metasurface 110, such that each of the sub-metagroup 110A, sub-metagroup 110B, sub-metagroup HOC, sub-metagroup 110D and sub-metagroup 110E can allow only the transmission of the desired color.Furthermore, the 110 metasurface can be modeled in a single processing cycle, thus reducing the occurrence of cosmetic defects. In other words, the 110 metasurface can be manufactured faster and at a lower cost.

[0075] With reference to [Fig. 4C], the cross-sectional view of the ambient light sensor 40C is shown. Compared to [Fig. 3C], the first transparent conductive film 108 can be arranged between the substrate 100 and the metasurface 110, and the second transparent conductive film 138 can be arranged between the adhesive layer 130 and the lower glass layer 140. The characteristics of the first transparent conductive film 108 and the second transparent conductive film 138 are similar to those illustrated in [Fig. 4A], and the details are not described again here to avoid repetition. According to certain embodiments of the present invention, the different wavelengths (or colors) of ambient light can be separated by the metasurface 110, such that each of the sub-metagroup 110A, sub-metagroup 110B, sub-metagroup HOC, sub-metagroup 110D and sub-metagroup 110E can allow only the transmission of the desired color.Furthermore, the 110 metasurface can be modeled in a single processing cycle, thus reducing the occurrence of cosmetic defects. In other words, the 110 metasurface can be manufactured faster and at a lower cost.

[0076] The present invention replaces the multiple conventional bandpass filters in the ambient light sensor with the metasurface. The different wavelengths (or colors) of ambient light can be separated by the metasurface, such that each of the sub-metagroups can allow only the transmission of the desired color, while the unwanted colors can be absorbed or reflected oppositely by the submetagroup. In other words, the metasurface can demonstrate the same bandpass filter function. Unlike conventional multiple bandpass filters that must be modeled separately and often induce poor coating, stripping, or other cosmetic defects, the metasurface of the present invention can be modeled in a single processing cycle, thus eliminating any cosmetic defects and potential misalignment. Consequently, the metasurface can be manufactured more quickly and at a lower cost.

[0077] The foregoing describes the characteristics of several embodiments so that a person skilled in the art can better understand aspects of the present invention. A person skilled in the art should understand that they can readily use the present invention as a basis for designing or modifying other processes and structures to achieve the same objectives and / or obtain the same advantages as the embodiments presented herein. A person skilled in the art should also understand that such equivalent constructions do not depart from the scope of the present invention, and that they can make various changes, substitutions, and modifications without departing from the scope of the present invention. Furthermore, although some embodiments of the present invention are disclosed above, they are not intended to limit the scope of the present invention.

[0078] References to features, advantages, or similar terms throughout this specification do not imply that all features and advantages that can be realized with the present invention should be or are in a single embodiment of the invention. On the contrary, terms referring to features and advantages mean that a specific feature, advantage, or characteristic described in connection with one embodiment is included in at least one embodiment of the present invention. Thus, discussions of features and advantages, and similar terms, throughout this specification may refer to, but not necessarily to, the same embodiment.

[0079] Furthermore, the features, advantages, and special characteristics described in the present invention can be combined in any way in one or more embodiments. Those skilled in the art will recognize, in light of the description given here, that the invention can be carried out without one or more of the specific features or advantages of a particular embodiment. In other cases, additional features and advantages may be found in certain embodiments that may not be present in all embodiments of the invention.

Claims

Demands

1. Ambient light sensor (10A, 10B, 10C, 20A, 20B, 20C, 30A, 30B, 30C, 40A, 40B, 40C), characterized in that it comprises: - a substrate (100); - a metasurface (110) disposed on the substrate (100), comprising: a plurality of nanostructures (112); and a filling layer (114) laterally surrounding the plurality of nanostructures (112); - an aperture layer (116) disposed on the substrate (100), the aperture layer (116) laterally separating the metasurface (110) into a plurality of sub-metagroups (110A, 110B, HOC, 110D, 110E); and - a diffusion structure disposed on the metasurface (110) and the aperture layer (116), the diffusion structure comprising one of: an assembly comprising an adhesive layer (130) covering the metasurface (110) and the aperture layer (116), and dispersed particles (132) disposed in the adhesive layer (130);and an assembly comprising a first layer of glue (130) covering the metasurface (110) and the aperture layer (116), a lens layer (152) disposed on the first layer of glue (130), the lens layer (152) having a curved surface, and a second layer of glue (150) covering the lens layer (152).

2. Ambient light sensor (10A, 10B, 10C, 20A, 20B, 20C, 30A, 30B, 30C, 40A, 40B, 40C) according to claim 1, characterized in that the aperture layer (116) comprises a black photoresin, a dielectric material or metals, in which the aperture layer (116) is arranged horizontally between the plurality of sub-metagroups (110A, 110B, HOC, 110D, 110E), or in which the aperture layer (116) is arranged above the metasurface (110).

3. Ambient light sensor (10A, 10B, 10C, 20A, 20B, 20C, 30A, 30B, 30C, 40A, 40B, 40C) according to claim 1, characterized in that it further comprises a plurality of sensing parts (104) integrated into the substrate (100), in which the plurality of sub-metagroups (110A, 110B, HOC, 110D, 110E) are arranged corresponding to the plurality of detection parts (104), respectively.

4. Ambient light sensor (10A, 10B, 10C, 20A, 20B, 20C, 30A, 30B, 30C, 40A, 40B, 40C) according to claim 1, characterized in that each of the plurality of nanostructures (112) has a circular shape, a rectangular shape or a hexagonal shape in top view, in which a thickness of the filling layer (114) is equal to a thickness of the plurality of nanostructures (112), or the thickness of the filling layer (114) is greater than the thickness of the plurality of nanostructures (112).

5. Ambient light sensor (10A, 10B, 10C, 20A, 20B, 20C, 30A, 30B, 30C, 40A, 40B, 40C) according to claim 1, characterized in that a refractive index of the plurality of nanostructures (112) is less than 1.4, in which a refractive index of the filling layer (114) is less than the refractive index of the plurality of nanostructures (112), in which the filling layer (114) is air.

6. Ambient light sensor (20A, 20B, 20C, 40A, 40B, 40C) according to claim 1, characterized in that a first transparent conductive film (108) is disposed between the substrate (100) and the metasurface (110), in which the first transparent conductive film (108) is a transparent conductive oxide, the transparent conductive oxide comprising indium tin oxide, fluorine-doped tin oxide, zinc oxide, or aluminum-doped zinc oxide.

7. Ambient light sensor (10B, 20B, 30B, 40B) according to claim 1, characterized in that it further comprises: - a spacing layer (120) disposed between the metasurface (110) and the diffusion structure.

8. Ambient light sensor (40B) according to claim 1, characterized in that the diffusion structure comprises the first layer of glue (130), the lens layer (152) and the second layer of glue (150), and characterized in that it further comprises: - a lower glass layer (140) disposed between the first layer of glue (130) and the lens layer (152); - a second transparent conductive film (138) disposed between the first layer of adhesive (130) and the lower glass layer (140); and - a top layer of glass (160) placed above the second layer of glue (150).

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