Image sensor including planar nanophotonic microlens array and electronic device including the same

Abstract

An image sensor including a planar nanophotonic microlens array and an electronic device including the same are provided. The image sensor includes a planar nanophotonic microlens array including a plurality of planar nanophotonic microlenses, wherein each of the plurality of planar nanophotonic microlenses includes a high refractive index nanostructure including a first dielectric material having a first refractive index and a low refractive index nanostructure including a dielectric material having a second refractive index lower than the first refractive index, and wherein each of the plurality of planar nanophotonic microlenses is offset toward a central portion of the planar nanophotonic microlens array and disposed at an outer edge of the planar nanophotonic microlens array.

Description

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2020-0189862, filed with the Korean Intellectual Property Office on December 31, 2020, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Example embodiments of this disclosure relate to image sensors including planar nanophotonic microlens arrays and electronic devices including image sensors, wherein the image sensors are capable of determining the optical curvature distribution of lens surfaces by using planar nanostructures. Background Technology

[0004] As image sensors and image capture modules are increasingly miniaturized, the principal ray angle (CRA) tends to increase at the edges of the image sensor. When the CRA increases at the edges, the sensitivity of pixels located at those edges decreases. Consequently, image edges can appear darker. Furthermore, the additional complex color calculations used to compensate for edge darkness add extra load to the image processing processor and reduce image processing speed. Summary of the Invention

[0005] One or more example embodiments provide an image sensor including a planar nanophotonic microlens array and an electronic device including the image sensor, wherein the image sensor is configured to more easily determine the optical curvature distribution of the lens surface by using planar nanostructures.

[0006] One or more example embodiments also provide an image sensor including a planar nanophotonic microlens array, the image sensor being configured to change the angle of incidence of incident light incident at a large principal ray angle (CRA) close to 90 degrees at the edge of the image sensor.

[0007] Additional aspects will be set forth in part in the description which follows, and will also be apparent in part from the description, or may be learned by practice of exemplary embodiments of this disclosure.

[0008] According to an example embodiment, an image sensor is provided, a sensor substrate including a plurality of photosensitive units respectively configured to sense light; and a planar nanophotonic microlens array including a plurality of planar nanophotonic microlenses, the plurality of planar nanophotonic microlenses having nanopatterned structures respectively configured to converge light to corresponding photosensitive units among the plurality of photosensitive units, wherein each of the plurality of planar nanophotonic microlenses includes: a high-refractive-index nanostructure including a first dielectric material having a first refractive index, and a low-refractive-index nanostructure including a second dielectric material having a second refractive index lower than the first refractive index, wherein the effective refractive index of each of the plurality of planar nanophotonic microlenses is maximized in the refractive index peak region of each of the plurality of planar nanophotonic microlenses and gradually decreases towards the outer edge of the refractive index peak region, wherein the effective refractive index corresponds to the ratio of the high-refractive-index nanostructure to the low-refractive-index nanostructure, and wherein each of the plurality of planar nanophotonic microlenses at the outer edge of the planar nanophotonic microlens array is offset towards the central portion of the planar nanophotonic microlens array.

[0009] At the center of the planar nanophotonic microlens array, the boundaries between multiple planar nanophotonic microlenses can coincide with the boundaries between the corresponding photosensitive units.

[0010] The distance by which each planar nanophotonic microlens at the outer edge of the planar nanophotonic microlens array is offset toward the center of the planar nanophotonic microlens array can increase as the distance of each planar nanophotonic microlens from the center of the planar nanophotonic microlens array increases.

[0011] In a plurality of planar nanophotonic microlenses, the refractive index peak region of each planar nanophotonic microlens located at the central portion of the planar nanophotonic microlens array can be set at the central portion of each planar nanophotonic microlens.

[0012] In a multi-planar nanophotonic microlens array, the refractive index peak region of each planar nanophotonic microlens located at the outer edge of the array can be shifted toward the central portion of the array.

[0013] The distance by which the refractive index peak region of each planar nanophotonic microlens at the outer edge of the planar nanophotonic microlens array is offset toward the center of the planar nanophotonic microlens array can increase as the distance of each planar nanophotonic microlens from the center of the planar nanophotonic microlens array increases.

[0014] Each of the multiple planar nanophotonic microlenses may include: a first region having a first effective refractive index; a second region being configured to be adjacent to the first region and having a second effective refractive index lower than the first effective refractive index of the first region; and a third region being configured to be adjacent to the second region and having a third effective refractive index lower than the second effective refractive index of the second region, wherein the first region, the second region, and the third region are arranged in a concentric circle shape.

[0015] In a plurality of planar nanophotonic microlenses, each planar nanophotonic microlens located at the central portion of the planar nanophotonic microlens array can have an effective refractive index distribution that is symmetrical about the central portion, and each planar nanophotonic microlens located at the outer edge of the planar nanophotonic microlens array can have an effective refractive index distribution that is asymmetrical about the central portion.

[0016] The total area of ​​multiple planar nanophotonic microlenses can be smaller than the total area of ​​the sensor substrate.

[0017] Each of the multiple planar nanophotonic microlenses may include multiple high-refractive-index nanostructures and multiple low-refractive-index nanostructures arranged in a concentric circle shape, and the width of each of the multiple high-refractive-index nanostructures in the diameter direction may be maximized in the refractive index peak region.

[0018] Each of the multiple planar nanophotonic microlenses may include multiple high-refractive-index nanostructures with nanopillar shapes, and the proportion of multiple high-refractive-index nanostructures may be maximized in the refractive index peak region.

[0019] Each of the multiple planar nanophotonic microlenses may include: multiple high-refractive-index nanostructures separated along the circumferential direction.

[0020] Each of the multiple planar nanophotonic microlenses may include: a high-refractive-index nanostructure with a plate shape and multiple low-refractive-index nanostructures with aperture shapes.

[0021] Each of the multiple planar nanophotonic microlenses may include a first layer and a second layer disposed on the first layer, and the patterns of high-refractive-index nanostructures and low-refractive-index nanostructures in the first layer may be different from the patterns of high-refractive-index nanostructures and low-refractive-index nanostructures in the second layer.

[0022] In the refractive index peak region of each of the multiple planar nanophotonic microlenses, the width of the high refractive index nanostructure in the first layer and the width of the high refractive index nanostructure in the second layer can be the same, and in the region outside the refractive index peak region, the width of the high refractive index nanostructure in the second layer can be smaller than the width of the high refractive index nanostructure in the first layer.

[0023] The image sensor may also include a spherical microlens disposed on each of the multiple planar nanophotonic microlenses.

[0024] In a multi-planar nanophotonic microlens array, the refractive index peak region of each planar nanophotonic microlens located at the central portion can be aligned with the optical axis of the corresponding spherical microlens to be consistent with each other.

[0025] The spherical microlenses at the outer edge of the planar nanophotonic microlens array can be offset relative to the corresponding planar nanophotonic microlenses toward the center of the planar nanophotonic microlens array.

[0026] The refractive index peak region of the planar nanophotonic microlens at the outer edge of the planar nanophotonic microlens array can be set at the center of the planar nanophotonic microlens.

[0027] The image sensor may also include a transparent dielectric layer disposed between the sensor substrate and the planar nanophotonic microlens array, wherein the thickness of the transparent dielectric layer increases from the center of the planar nanophotonic microlens array toward the outer edge of the planar nanophotonic microlens array.

[0028] The transparent dielectric layer can have an inclined upper surface, so that the thickness of the transparent dielectric layer gradually increases from the center of the planar nanophotonic microlens array toward the outer edge of the planar nanophotonic microlens array, and multiple planar nanophotonic microlenses can be arranged at a certain angle on the inclined upper surface of the transparent dielectric layer.

[0029] The transparent dielectric layer can have a stepped shape, wherein the thickness of the transparent dielectric layer increases discontinuously from the central part of the planar nanophotonic microlens array toward the outer edge of the planar nanophotonic microlens array.

[0030] The image sensor may also include a transparent dielectric layer disposed on a planar nanophotonic microlens array, the thickness of which increases from the center of the planar nanophotonic microlens array toward the outer edge of the array.

[0031] The image sensor may also include: a spherical microlens array, comprising multiple spherical microlenses disposed in the central portion of the planar nanophotonic microlens array, wherein the multiple planar nanophotonic microlenses may not be disposed in the central portion of the planar nanophotonic microlens array.

[0032] Spherical microlens arrays and planar nanophotonic microlens arrays can be arranged on the same plane.

[0033] Low-refractive-index nanostructures can be set in the central part of a planar nanophotonic microlens array, and spherical microlens arrays can be set on the low-refractive-index nanostructures in the central part of the planar nanophotonic microlens array.

[0034] The image sensor may further include a color filter layer disposed on a sensor substrate, wherein the color filter layer may include a plurality of color filters configured to transmit light of a specific wavelength and absorb or reflect light of other wavelengths besides the specific wavelength, and a planar nanophotonic microlens array may be disposed on the color filter layer.

[0035] The image sensor may further include: a transparent spacer layer disposed on a planar nanophotonic microlens array; and a dichroic lens array disposed on the spacer layer, wherein the dichroic lens array is configured to: change the phase of a first wavelength of incident light and the phase of a second wavelength of incident light, the first and second wavelengths being different from each other, so that the first wavelength of light and the second wavelength of light propagate in different directions, thereby converging the first wavelength of light onto a first photosensitive unit among a plurality of photosensitive units, and converging the second wavelength of light onto a second photosensitive unit among a plurality of photosensitive units that is different from the first photosensitive unit.

[0036] According to another aspect of an example embodiment, an electronic device is provided, comprising: an image sensor configured to convert an optical image into an electrical signal; and a processor configured to control operation of the image sensor and to store and output signals generated by the image sensor, wherein the image sensor includes: a sensor substrate including a plurality of photosensitive units respectively configured to sense light; and a planar nanophotonic microlens array including a plurality of planar nanophotonic microlenses, the plurality of planar nanophotonic microlenses having nanopattern structures respectively configured to converge light to corresponding photosensitive units among the plurality of photosensitive units, wherein each of the plurality of planar nanophotonic microlenses includes: including a first fold The array comprises a high-refractive-index nanostructure of a first dielectric material and a low-refractive-index nanostructure of a second dielectric material having a second refractive index lower than the first refractive index. The effective refractive index of each of the plurality of planar nanophotonic microlenses is maximized in the refractive index peak region of each of the plurality of planar nanophotonic microlenses and gradually decreases toward the outer edge of the refractive index peak region. The effective refractive index corresponds to the ratio of the high-refractive-index nanostructure to the low-refractive-index nanostructure. Furthermore, each of the plurality of planar nanophotonic microlenses at the outer edge of the planar nanophotonic microlens array is offset toward the central portion of the planar nanophotonic microlens array.

[0037] According to another aspect of an example embodiment, an image sensor is provided, the image sensor comprising: a sensor substrate including a plurality of photosensitive units respectively configured to sense light; and a planar nanophotonic microlens array including a plurality of planar nanophotonic microlenses, the plurality of planar nanophotonic microlenses having nanopattern structures respectively configured to converge light to corresponding photosensitive units among the plurality of photosensitive units, wherein each of the plurality of planar nanophotonic microlenses includes: a high-refractive-index nanostructure including a first dielectric material having a first refractive index, and a low-refractive-index nanostructure including a second dielectric material having a second refractive index lower than the first refractive index, the plurality of planar nanophotonic microlenses being... The effective refractive index of each planar nanophotonic microlens is maximized in the refractive index peak region of each of the multiple planar nanophotonic microlenses, and gradually decreases towards the outer edge of the refractive index peak region. The effective refractive index corresponds to the ratio of high-refractive-index nanostructures to low-refractive-index nanostructures. Furthermore, each planar nanophotonic microlens at the outer edge of the planar nanophotonic microlens array is offset towards the central portion of the planar nanophotonic microlens array, and the refractive index peak region of each planar nanophotonic microlens at the outer edge of the planar nanophotonic microlens array is offset towards the central portion of the planar nanophotonic microlens array. Attached Figure Description

[0038] The above and / or other aspects, features, and advantages of certain exemplary embodiments of the present disclosure will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0039] Figure 1 This is a block diagram of an image sensor according to an example embodiment;

[0040] Figure 2 This is a conceptual diagram illustrating a camera module according to an example embodiment;

[0041] Figure 3 This is a plan view illustrating the pixel array of an image sensor according to an example embodiment;

[0042] Figure 4A It is along Figure 3 A schematic cross-sectional view of the pixel array of the image sensor shown, taken from line AA′ at the center.

[0043] Figure 4B Showing is equivalent to Figure 4A An example of a spherical microlens is shown for a planar nanophotonic microlens;

[0044] Figure 5 It is shown Figure 4AA planar view illustrating an example of the shape of a planar nanophotonic microlens;

[0045] Figure 6 Show Figure 4A An example of the effective refractive index distribution of a planar nanophotonic microlens is shown;

[0046] Figure 7A It is along Figure 3 The image sensor shown is a cross-sectional view taken from the edge of the pixel array by line BB′.

[0047] Figure 7B Showing is equivalent to Figure 7A An example of a spherical microlens is shown for a planar nanophotonic microlens;

[0048] Figure 8 Show Figure 7A An example of the effective refractive index distribution of a planar nanophotonic microlens is shown;

[0049] Figure 9 , Figure 10 and Figure 11 This is a planar view illustrating examples of various shapes of planar nanophotonic microlenses according to another exemplary embodiment;

[0050] Figure 12 and Figure 13 This is a cross-sectional view illustrating an example of the shape of a planar nanophotonic microlens according to another exemplary embodiment;

[0051] Figure 14 , Figure 15 and Figure 16 This is a cross-sectional view illustrating an example of the shape of a planar nanophotonic microlens, which also includes a spherical microlens, according to another exemplary embodiment;

[0052] Figure 17 , Figure 18 , Figure 19 and Figure 20 This is a cross-sectional view showing the pixel array of an image sensor according to another example embodiment;

[0053] Figure 21 This is a plan view illustrating the pixel array of an image sensor according to another example embodiment;

[0054] Figure 22 It shows along Figure 21 The image sensor shown is a cross-sectional view of an example of the pixel array cut by line CC′.

[0055] Figure 23 It shows along Figure 21 Another example cross-sectional view of the pixel array of the image sensor shown, taken by line CC′;

[0056] Figure 24A , Figure 24B and Figure 24C Examples of various pixel arrangements for pixel arrays are shown;

[0057] Figure 25A and Figure 25B This is a conceptual diagram illustrating the structure and function of a dichroic lens array according to an example embodiment;

[0058] Figure 26A and Figure 26B This is a schematic cross-sectional view of the pixel array of an image sensor according to an example embodiment;

[0059] Figure 27A This is a plan view showing the arrangement of the photosensitive units. Figure 27B This is a plan view illustrating an example arrangement of nanopillars in a dichroic lens array, and Figure 27C yes Figure 27B A detailed enlarged plan view of a portion;

[0060] Figure 28A Show along Figure 27B The phase distribution of the first and second wavelength light passing through the dichroic lens array, line II′ Figure 28B The phase of the first wavelength light passing through the dichroic lens array is shown at the center of the first to fourth regions, and Figure 28C The phase of the second wavelength light passing through the dichroic lens array is shown at the center of the first to fourth regions;

[0061] Figure 28D Showing the incident at Figure 28A and Figure 28B An example of the direction of travel of the first wavelength of light in and around the first region of the dichroic lens array, and Figure 28E An example of a microlens array that is equivalent to a dichroic lens array relative to the first wavelength of light is shown;

[0062] Figure 28F Showing the incident at Figure 28A and Figure 28B An example of the direction of travel of the second wavelength light in and around the second region of the dichroic lens array, and Figure 28G An example of a microlens array that is equivalent to a dichroic lens array relative to the second wavelength of light is shown;

[0063] Figure 29A Show along Figure 27B The phase distribution of the first and third wavelength light passing through the dichroic lens array is shown by line II-II′. Figure 29B The phase of the third wavelength light passing through the dichroic lens array is shown at the center of the first to fourth regions, and Figure 29CThe phase of the first wavelength of light passing through the dichroic lens array is shown at the center of the first to fourth regions;

[0064] Figure 29D Showing the incident at Figure 29A and Figure 29B An example of the direction of travel of the third wavelength light in and around the third region of the dichroic lens array, and Figure 29E An example of a microlens array that is equivalent to a dichroic lens array relative to a third wavelength of light is shown;

[0065] Figure 29F Showing the incident at Figure 29A and Figure 29B An example of the direction of travel of the first wavelength light in and around the fourth region of the dichroic lens array, and Figure 29G An example of a microlens array that is equivalent to a dichroic lens array relative to the first wavelength of light is shown;

[0066] Figure 30A , Figure 30B and Figure 30C It is a planar diagram showing how the arrangement of the nanopillars of the dichroic lens array changes according to their position on the pixel array;

[0067] Figure 31 This is a cross-sectional view illustrating the structure of the pixel array of an image sensor according to another example embodiment;

[0068] Figure 32 This is a cross-sectional view illustrating the structure of the pixel array of an image sensor according to another example embodiment;

[0069] Figure 33 This is a plan view illustrating an example of the offset morphology of nanopillars arranged in a two-dimensional array of dichroic lenses;

[0070] Figure 34A and Figure 34B This is a plan view illustrating an example of a unit pattern of a dichroic lens array that can be applied to an image sensor of the Bayer pattern type according to another example embodiment;

[0071] Figure 35 This is a block diagram illustrating an example of an electronic device including an image sensor according to an exemplary embodiment;

[0072] Figure 36 It is shown Figure 35 A block diagram of the camera module; and

[0073] Figure 37 , Figure 38 , Figure 39 , Figure 40 , Figure 41 , Figure 42 , Figure 43, Figure 44 , Figure 45 and Figure 46 Various examples of electronic devices using image sensors according to exemplary embodiments are shown. Detailed Implementation

[0074] Referring now to the exemplary embodiments shown in the accompanying drawings, wherein the same reference numerals refer to the same elements throughout the drawings. In this respect, exemplary embodiments may take different forms and should not be construed as limited to the description set forth herein. Therefore, exemplary embodiments are described below only with reference to the accompanying drawings to explain various aspects.

[0075] As used herein, the term "and / or" includes any and all combinations of one or more items in the related list. Expressions such as "at least one of..." modify the entire list of elements when following it, rather than individual elements within the list. For example, the expression "at least one of a, b, and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0076] In the following, an image sensor including a planar nanophotonic microlens array and an electronic device including the image sensor will be described in detail with reference to the accompanying drawings. Embodiments of this disclosure are subject to various modifications and can be embodied in many different forms. In the drawings, similar reference numerals denote similar components, and the dimensions of components in the drawings may be enlarged for ease of illustration.

[0077] When a layer, film, region, or plate is referred to as being "on" another element, it can be placed directly above / below / to the left / right of another layer or substrate, or an intermediate layer may also be present.

[0078] It should be understood that although the terms "first" and "second," etc., may be used herein to describe individual components, these components should not be limited by these terms. These terms are used only to distinguish the components from one another. These terms do not limit the materials or structures of the components to be different from one another.

[0079] Singular expressions encompass plural expressions unless there is a clear distinction in the context. It will also be understood that when a part is referenced as "including" another component, that part may not exclude the other component, but may also include it, unless the context otherwise indicates.

[0080] Furthermore, terms such as “unit” and “module” used herein refer to units that perform functions or operations and can be implemented by hardware, software, or a combination of hardware and software.

[0081] The use of the term "above" and similar indicative terms can correspond to both the singular and plural forms.

[0082] The steps of all the methods described herein may be performed in any suitable order, unless otherwise indicated herein or the context expressly indicates otherwise. The use of all exemplary terms (e.g., etc.) is solely for the purpose of describing the technical ideas in detail, and the scope of the claims is not limited by these terms unless the context is limited by the claims.

[0083] Figure 1 This is a block diagram of an image sensor 1000 according to an example embodiment. (Reference) Figure 1 The image sensor 1000 may include a pixel array 1100, a timing controller (T / C) 1010, a line decoder 1020, and an output circuit 1030. The image sensor 1000 may include a charge-coupled device (CCD) image sensor or a complementary metal-oxide-semiconductor (CMOS) image sensor.

[0084] Pixel array 1100 includes pixels arranged in two dimensions along multiple rows and columns. Row decoder 1020 selects one of the rows in pixel array 1100 in response to a row address signal output from timing controller 1010. Output circuit 1030 outputs a light-sensing signal from column cells of the multiple pixels arranged in the selected row. For this purpose, output circuit 1030 may include a column decoder and an analog-to-digital converter (ADC). For example, output circuit 1030 may include multiple ADCs arranged according to columns between column decoder and pixel array 1100, or a single ADC arranged at the output of column decoder. Timing controller 1010, row decoder 1020, and output circuit 1030 may be implemented as a single chip or separate chips. Processor for processing the image signal output from output circuit 1030 may be implemented as a single chip having timing controller 1010, row decoder 1020, and output circuit 1030.

[0085] The image sensor 1000 can be applied to various optical devices such as camera modules. For example, Figure 2 This is a schematic diagram illustrating a concept of a camera module 1880 according to an example embodiment.

[0086] refer to Figure 2The camera module 1880 may include: a lens assembly 1910 that forms an optical image by focusing light reflected from an object; an image sensor 1000 that converts the optical image formed by the lens assembly 1910 into an electrical image signal; and an image signal processor 1960 that processes the electrical image signal output from the image sensor 1000 into an image signal. The camera module 1880 may also include: an infrared blocking filter disposed between the image sensor 1000 and the lens assembly 1910; a display panel that displays the image formed by the image signal processor 1960; and a memory that stores the image data formed by the image signal processor 1960. Such a camera module 1880 can be installed in a mobile electronic device (e.g., a cellular phone, a laptop computer, a tablet PC, etc.).

[0087] Lens assembly 1910 is used to focus images of objects outside camera module 1880 onto image sensor 1000, and more precisely, onto pixel array 1100 of image sensor 1000. Figure 2 In this diagram, for convenience, a single lens is shown as lens assembly 1910, but lens assembly 1910 may include multiple lenses. When the pixel array 1100 is precisely positioned on the focal plane of lens assembly 1910, light emitted from any point on the object is refocused onto a point on the pixel array 1100 via lens assembly 1910. For example, light emitted from any point A on the optical axis OX passes through lens assembly 1910 and then focuses at the center of pixel array 1100 on optical axis OX. Light emitted from any point B, C, or D offset from optical axis OX passes through lens assembly 1910, crosses optical axis OX, and focuses at a point on the outer edge of pixel array 1100. For example, light emitted from point B above optical axis OX passes through optical axis OX and focuses at the lower edge of pixel array 1100, and light emitted from point C below optical axis OX passes through optical axis OX and focuses at the upper edge of pixel array 1100. Furthermore, light emitted from point D, located between optical axis OX and point B, focuses between the center and lower edge of pixel array 1100.

[0088] Therefore, light emitted from different points A, B, C, and D strikes the pixel array 110 at different angles depending on the distance between points A, B, C, and D and the optical axis OX. The angle of incidence of light incident on the pixel array 1100 is typically defined as the principal ray angle (CRA). The principal ray is the ray that strikes the pixel array 1100 from the point where the object intersects the center of the lens assembly 1910, and the CRA is the angle formed by the principal ray and the optical axis OX. Light emitted from point A on the optical axis OX has a CRA of 0 degrees and strikes the pixel array 1100 perpendicularly. The farther the light source is from the optical axis OX, the larger the CRA.

[0089] Based on the viewpoint of the image sensor 1000, the CRA of light incident on the central portion of the pixel array 1100 is 0 degrees, and the CRA of the incident light increases towards the edges of the pixel array 1100. For example, the CRA of light emanating from points B and C and incident on the outermost edge of the pixel array 1100 can be maximum, while the CRA of light emanating from point A and incident on the central portion of the pixel array 1100 is 0 degrees. Furthermore, the CRA of light emanating from point D and incident between the center and edge of the pixel array 1100 is less than the CRA of light emanating from points B and C, but greater than 0 degrees.

[0090] Therefore, the CRA of the incident light incident on the pixels in the pixel array 1100 varies depending on the pixel's position. Specifically, the CRA gradually increases from the center of the pixel array 1100 towards the edges. When the CRA of the incident light incident on the pixel increases, the pixel's sensitivity may decrease. According to an example embodiment, in order to prevent or reduce the sensitivity decrease of pixels located at the edges of the pixel array 1100, a planar nanophotonic microlens array may be disposed in the pixel array 1100 of the image sensor 1000.

[0091] Figure 3 This is a plan view showing the pixel array 1100 of the image sensor 1000 according to an example embodiment. Figure 4A It is along Figure 3 A schematic cross-sectional view taken from line AA′ of the central portion of the pixel array 1100 of the image sensor 1000 shown. (Reference) Figure 3 and Figure 4A The pixel array 1100 of the image sensor 1000 may include: a sensor substrate 110; a color filter layer 140 disposed on the sensor substrate 110; and a planar nanophotonic microlens array 150 disposed on the color filter layer 140.

[0092] refer to Figure 4A The sensor substrate 110 may include a plurality of photosensitive units 111, 112 and 113 for sensing light. For example, the sensor substrate 110 may include a first photosensitive unit 111, a second photosensitive unit 112 and a third photosensitive unit 113 for converting light into electrical signals. Figure 4A The first photosensitive unit 111, the second photosensitive unit 112, and the third photosensitive unit 113 are shown arranged sequentially in the horizontal direction as an example, but the embodiment is not limited thereto. The plurality of photosensitive units 111, 112, and 113 of the sensor substrate 110 can be arranged in two dimensions in various ways.

[0093] The color filter layer 140 may include a plurality of color filters 141, 142, and 143, which transmit only light of a specific wavelength and absorb or reflect light of other wavelengths. For example, the color filter layer 140 may include: a first color filter 141 disposed on the first photosensitive unit 111 and configured to transmit only light of the first wavelength; a second color filter 142 disposed on the second photosensitive unit 112 and configured to transmit only light of a second wavelength different from the first wavelength; and a third color filter 143 disposed on the photosensitive unit 113 and configured to transmit only light of a third wavelength different from the first and second wavelengths. Figure 4A The first color filter 141, the second color filter 142, and the third color filter 143 are shown arranged sequentially in the horizontal direction as an example, but the embodiment is not limited thereto. The plurality of color filters 141, 142, and 143 of the color filter layer 140 can be arranged in two dimensions in various ways.

[0094] The planar nanophotonic microlens array 150 disposed on the color filter layer 140 may include a plurality of planar nanophotonic microlenses 151 arranged in two dimensions. The plurality of planar nanophotonic microlenses 151 may correspond one-to-one with a plurality of color filters 141, 142, and 143, and may also correspond one-to-one with a plurality of photosensitive units 111, 112, and 113. Each of the plurality of planar nanophotonic microlenses 151 may be configured to focus light onto a corresponding photosensitive unit among the plurality of photosensitive units 111, 112, and 113. For this purpose, the plurality of planar nanophotonic microlenses 151 may have a nanopattern structure configured to converge light.

[0095] Figure 5 It is shown Figure 4A A planar view illustrating an example shape of the planar nanophotonic microlens 151. (Reference) Figure 5 The planar nanophotonic microlens 151 may include: a high-refractive-index nanostructure 151H; and a low-refractive-index nanostructure 151L filled between the high-refractive-index nanostructures 151H. The high-refractive-index nanostructures 151H may include dielectric materials with high refractive indices, such as titanium oxide (TiO2), gallium nitride (GaN), silicon nitride (SiN3), zinc sulfide (ZnS), zinc selenide (ZnSe), silicon nitride (Si3N4), etc., and have a low absorption coefficient in the visible light band. The low-refractive-index nanostructures 151L may include dielectric materials with low refractive indices, such as silicon oxide (SiO2), siloxane spin-coated glass (SOG), air, etc., and have a low absorption coefficient in the visible light band.

[0096] The effective refractive index of the planar nanophotonic microlens 151 can be maximized in any region of the planar nanophotonic microlens 151 and can gradually decrease towards the outer edge of the region, so that the planar nanophotonic microlens 151 can be configured as a convex lens for focusing light. For example, the ratio of high refractive index nanostructure 151H to low refractive index nanostructure 151L can be maximized in any region of the planar nanophotonic microlens 151 and can gradually decrease towards the outer edge of the region. In the following text, the region in the planar nanophotonic microlens 151 with the maximum effective refractive index is referred to as the refractive index peak region. To satisfy these conditions, the widths and spacings of the low refractive index nanostructure 151L and the high refractive index nanostructure 151H can be selected differently in the refractive index peak region and its outer edge of the planar nanophotonic microlens 151. For example, multiple high-refractive-index nanostructures 151H and multiple low-refractive-index nanostructures 151L can be arranged in a concentric circle shape relative to the refractive index peak region, and the width of the high-refractive-index nanostructure 151H in the diameter direction can be the largest in the refractive index peak region.

[0097] Furthermore, the planar nanophotonic microlens 151 can be configured to change the incident angle of the incident light so that the light is incident at an angle of almost 90 degrees at the center of the photosensitive unit corresponding to the planar nanophotonic microlens 151. As described above, the CRA of the incident light varies depending on its position on the pixel array 1100. Therefore, the position of the refractive index peak region in the planar nanophotonic microlens 151 can vary depending on the position of the planar nanophotonic microlens 151 in the pixel array 1100.

[0098] When light is located in the central portion of the pixel array 1100 (i.e., the portion where light is incident at approximately a 90-degree angle), the planar nanophotonic microlens 151 does not need to change the angle of light travel. Therefore, as Figure 4A As shown, the refractive index peak region of the planar nanophotonic microlens 151, which is set in the central part of the pixel array 1100, can be set at the center of the planar nanophotonic microlens 151. Figure 6 Show Figure 4A An example of the effective refractive index distribution of the planar nanophotonic microlens 151 is shown. (Reference) Figure 6 The planar nanophotonic microlens 151 disposed at the center of the pixel array 1100 may include: a first region 151a disposed at the center; a second region 151b surrounding the first region 151a; a third region 151c surrounding the second region 151b; a fourth region 151d surrounding the third region 151c; and a fifth region 151e surrounding the fourth region 151d. The first region 151a to the fifth region 151e may be arranged in a concentric circle shape with the center of the planar nanophotonic microlens 151 as the origin.

[0099] The first region 151a is positioned at the very center, where it can have the maximum effective refractive index. For example, the ratio of high-refractive-index nanostructure 151H to low-refractive-index nanostructure 151L can be maximized in the first region 151a. The planar nanophotonic microlens 151 can have an effective refractive index distribution that gradually decreases from the first region 151a to the fifth region 151e. The effective refractive index of the second region 151b is lower than that of the first region 151a, the effective refractive index of the third region 151c is lower than that of the second region 151b, and the effective refractive index of the fourth region 151d is lower than that of the third region 151c. Furthermore, the effective refractive index of the fifth region 151e is the lowest. For this purpose, at least one of the widths and spacings of each of the low-refractive-index nanostructure 151L and the high-refractive-index nanostructure 151H in the first to fifth regions 151e can be selected differently.

[0100] In this structure, the planar nanophotonic microlens 151 can have an effective refractive index distribution that is about centrosymmetric. Furthermore, the refractive index peak region of the planar nanophotonic microlens 151 is located at the center of the planar nanophotonic microlens 151 (specifically, the first region 151a). Figure 6 The planar nanophotonic microlens 151 shown has five concentric circles, but the embodiment is not limited to this. For example, the number of concentric circles can be selected differently depending on the size of the planar nanophotonic microlens 151, the effective refractive index profile required by the planar nanophotonic microlens 151, etc.

[0101] Figure 4B Showing is equivalent to Figure 4A The example shown is a spherical microlens of the planar nanophotonic microlens 151. When Figure 4A The planar nanophotonic microlens 151 shown has Figure 6 With the effective refractive index distribution shown, the same optical effect as when the optical axis is located at the center of an equivalent spherical microlens can be obtained, wherein the center of the equivalent spherical microlens coincides with the center of the corresponding photosensitive unit and color filter. Furthermore, the equivalent spherical microlens can have a lens surface symmetrical about the optical axis. In this case, light incident perpendicularly on the pixel array 1100 can pass through the planar nanophotonic microlens 151 and the color filter layer 140 to be incident perpendicularly on the sensor substrate 110. Therefore, at the central portion of the pixel array 1100, the refractive index peak region can be located at the center of the planar nanophotonic microlens 151, and the planar nanophotonic microlens 151 can be configured such that the refractive index peak region coincides with the center of the corresponding photosensitive unit and color filter.

[0102] refer to Figure 4AAt the center of the pixel array 1100, the boundaries between the planar nanophotonic microlenses 151 can coincide with the boundaries between the corresponding photosensitive units and the corresponding color filters. Therefore, the area where the planar nanophotonic microlenses 151 are set can coincide with the area where the corresponding photosensitive units and color filters are arranged.

[0103] Figure 7A This is a cross-sectional view taken along line BB′ of the edge of the pixel array 1100 of the image sensor. (Reference) Figure 3 and Figure 7A Within the edge of the pixel array 1100, the planar nanophotonic microlens 151 can be offset in the direction of light incidence, and the refractive index peak region of the planar nanophotonic microlens 151 can also be offset in the direction of light incidence. For example, within the edge of the pixel array 1100, the planar nanophotonic microlens 151 can be offset towards the center of the pixel array 1100, and the refractive index peak region of the planar nanophotonic microlens 151 can also be offset towards the center of the pixel array 1100. For example, the planar nanophotonic microlens 151 disposed at the right edge of the pixel array 1100, and its refractive index peak region, can be offset to the left, and the planar nanophotonic microlens 151 disposed at the left edge of the pixel array 1100, and its refractive index peak region, can be offset to the right. Therefore, the boundary between the planar nanophotonic microlenses 151 disposed at the edge of the pixel array 1100 may not coincide with the boundary between the corresponding photosensitive units and the boundary between the corresponding color filters. In this case, the total area of ​​the planar nanophotonic microlens array 150 can be smaller than the total area of ​​the pixel array 1100, the total area of ​​the sensor substrate 110, or the total area of ​​the color filter layer 140.

[0104] Figure 3 The planar nanophotonic microlens 151 arranged on the outermost edge is shown as an example, but planar nanophotonic microlenses 151 arranged between the center and the edge of the pixel array 1100 can also be offset towards the center of the pixel array 1100. The offset distance of the planar nanophotonic microlens 151 and its refractive index peak region can be determined based on the CRA of the incident light. As the CRA of the incident light increases, the offset distance of the planar nanophotonic microlens 151 and its refractive index peak region increases. Therefore, as the planar nanophotonic microlens 151 moves away from the center of the pixel array 1100, the offset distance of the planar nanophotonic microlens 151 and its refractive index peak region can gradually increase.

[0105] According to another example embodiment, the pixel array 1100 can be divided into multiple regions based on its distance from the center, and the offset distance between the planar nanophotonic microlens 151 and the refractive index peak region of the planar nanophotonic microlens 151 can be gradually changed according to the divided regions. In this case, the planar nanophotonic microlenses 151 arranged in the same region of the pixel array 1100 can be offset by the same distance. The refractive index peak regions of the planar nanophotonic microlenses 151 arranged in the same region of the pixel array 1100 can also be offset by the same distance.

[0106] Figure 8 Show Figure 7A An example of the effective refractive index distribution of the planar nanophotonic microlens 151 is shown. (Reference) Figure 8 The planar nanophotonic microlens 151 disposed at the edge of the pixel array 1100 may include: a first region 151a disposed outside the center; a second region 151b surrounding the first region 151a; a third region 151c surrounding the second region 151b; a fourth region 151d surrounding the third region 151c; and a fifth region 151e surrounding the fourth region 151d. The first regions 151a to the fifth regions 151e may be arranged in a concentric circle shape offset from the center of the planar nanophotonic microlens 151. As described above, the planar nanophotonic microlens 151 may have an effective refractive index distribution that gradually decreases from the first region 151a to the fifth region 151e. Therefore, the planar nanophotonic microlens 151 may have an effective refractive index distribution that is asymmetrical about the center, and the refractive index peak region of the planar nanophotonic microlens 151 is set to be offset from the center of the planar nanophotonic microlens 151.

[0107] The position of the first region 151a can vary depending on the relative position of the planar nanophotonic microlens 151 and the pixel array 1100. The farther the planar nanophotonic microlens 151 is from the center of the pixel array 1100, the farther the position of the first region 151a can be from the center of the planar nanophotonic microlens 151. The first region 151a can also be offset towards the center of the pixel array 1100. For example, the first region 151a can be offset to the left from the center of the planar nanophotonic microlens 151 located at the right edge of the pixel array 1100.

[0108] Figure 7B Showing is equivalent to Figure 7A The example shown is a spherical microlens of the planar nanophotonic microlens 151. When Figure 7A The planar nanophotonic microlens 151 shown has Figure 8When the effective refractive index distribution shown is obtained, the same optical effect can be achieved as when the optical axis of an equivalent spherical microlens is offset from the center of the photosensitive unit and color filter corresponding to the spherical microlens.

[0109] Furthermore, the equivalent spherical microlens can have a lens surface asymmetrical about the optical axis. The optical axis of the equivalent spherical microlens, as well as the equivalent spherical microlens itself, can also be offset relative to the corresponding photosensitive unit and color filter. In this case, light incident obliquely on the pixel array 1100 can pass through the planar nanophotonic microlens 151 and the color filter layer 140 to be incident approximately perpendicularly on the sensor substrate 110. Furthermore, the planar nanophotonic microlens 151 can converge the light towards approximately the center of the corresponding photosensitive unit.

[0110] The aforementioned planar nanophotonic microlens array 150 has a planar nanostructure, thus the optical curvature distribution of the lens surface can be determined more easily compared to that of a spherical microlens array. For example, by selecting different widths and spacings of the low-refractive-index nanostructures 151L and high-refractive-index nanostructures 151H according to the concentric regions within each planar nanophotonic microlens 151, it is easier to design planar nanophotonic microlenses 151 with a desired effective refractive index distribution. Therefore, it is easier to design and manufacture planar nanophotonic microlenses 151 with an optimal shape based on the CRA of the incident light incident on the pixel array 1100 of the image sensor. As described above, the planar nanophotonic microlens array 150 can also change the incident angle of the incident light incident at the edge of the pixel array 1100 of the image sensor with a maximum CRA close to 90 degrees. Specifically, the planar nanophotonic microlens array 150 may include various types of planar nanophotonic microlenses 151, which take into account changes in the CRA at each position on the pixel array 1100 of the image sensor. Therefore, similar to the sensitivity of pixels disposed at the center portion of the pixel array 1100, the sensitivity of pixels disposed at the edges of the pixel array 1100 of the image sensor can be improved.

[0111] Figure 5 The examples show a low-refractive-index nanostructure 151L and a high-refractive-index nanostructure 151H with toroidal structures, but the embodiments are not necessarily limited to this. For example, Figures 9 to 11 This is a planar view showing examples of various shapes of the planar nanophotonic microlens 151.

[0112] refer to Figure 9The planar nanophotonic microlens 151 may include a plurality of high-refractive-index nanostructures 151H having a nanopillar shape. In this case, the proportion of the plurality of high-refractive-index nanostructures 151H can be highest in the refractive index peak region of the planar nanophotonic microlens 151, and the proportion of the plurality of high-refractive-index nanostructures 151H can decrease as they move away from the refractive index peak region. Figure 9 The diagram shows multiple high-refractive-index nanostructures 151H arranged in a circular shape, but these high-refractive-index nanostructures 151H could also be, for example, elliptical or polygonal. Furthermore, Figure 9 The illustration shows that the dimensions (e.g., diameters) of the multiple high-refractive-index nanostructures 151H are large in the refractive index peak region, and the dimensions of the multiple high-refractive-index nanostructures 151H decrease towards the outer edge; however, the embodiments are not necessarily limited to this. For example, the dimensions of the multiple high-refractive-index nanostructures 151H may be the same, and the density of the multiple high-refractive-index nanostructures 151H may decrease from the refractive index peak region towards the outer edge.

[0113] refer to Figure 10 The planar nanophotonic microlens 151 may further include a plurality of high-refractive-index nanostructures 151H separated along a circumferential direction. Each high-refractive-index nanostructure 151H may be arc-shaped. Even in this case, the proportion of the plurality of high-refractive-index nanostructures 151H can be designed to be maximum in the refractive index peak region of the planar nanophotonic microlens 151, and the proportion of the plurality of high-refractive-index nanostructures 151H can be designed to decrease as the plurality of high-refractive-index nanostructures 151H moves away from the refractive index peak region.

[0114] refer to Figure 11 The planar nanophotonic microlens 151 may further include: a high-refractive-index nanostructure 151H in the form of a plate; and a plurality of low-refractive-index nanostructures 151L in the form of holes. For this purpose, the plurality of holes can be formed by etching the high-refractive-index nanostructure 151H, and the low-refractive-index material can fill the holes. According to another example embodiment, the holes may not be filled and may be empty. In this case, the low-refractive-index nanostructures 151L may include air. Although the diameter of all holes in the planar nanophotonic microlens 151 may be the same, the diameter of the holes may increase as the holes move away from the refractive index peak region. In the refractive index peak region, the number of holes and / or the diameter of the holes may be small to make the proportion of high-refractive-index nanostructures 151H high, and as the holes move away from the refractive index peak region, the number of holes and / or the diameter of the holes may increase to make the proportion of high-refractive-index nanostructures 151H decrease.

[0115] Figure 12 and Figure 13This is a cross-sectional view illustrating an example of the shape of a planar nanophotonic microlens 151 according to another exemplary embodiment. Figure 12 and Figure 13 As shown, the planar nanophotonic microlens 151 can have a multilayer structure. For example, the planar nanophotonic microlens 151 may include a first layer L1 and a second layer L2 stacked on the first layer L1. Each of the first layer L1 and the second layer L2 may include a high-refractive-index nanostructure 151H and a low-refractive-index nanostructure 151L, and the pattern of the high-refractive-index nanostructure 151H and the low-refractive-index nanostructure 151L in the first layer L1 may be different from the pattern of the high-refractive-index nanostructure 151H and the low-refractive-index nanostructure 151L in the second layer L2. The effective refractive index of the planar nanophotonic microlens 151 with a multilayer structure in each region can be determined by placing the high-refractive-index nanostructure 151H in the first layer L1 and the low-refractive-index nanostructure 151L in the first layer L1 and the second layer L2 together.

[0116] refer to Figure 12 Both the first layer L1 and the second layer L2 can have a centrally symmetrical shape about the central portion where the incident light Li is perpendicularly incident on the pixel array 1100. The high-refractive-index nanostructures 151H in the first layer L1 and the second layer L2 can have the same width at the center of the planar nanophotonic microlens 151, but at the outer edge, the width of the high-refractive-index nanostructure 151H in the upper second layer L2, where light is first incident, can be smaller than the width of the high-refractive-index nanostructure 151H in the lower first layer L1. Furthermore, the effective refractive index of the planar nanophotonic microlens 151, considering the first layer L1 and the second layer L2 together, can be highest near the center of the planar nanophotonic microlens 151 and can gradually decrease towards the outer edge of the refractive index peak region.

[0117] refer to Figure 13Both the first layer L1 and the second layer L2 can have an asymmetrical shape with respect to the center of the planar nanophotonic microlens 151 located at the outer edge where the incident light Li is obliquely incident on the pixel array 1100. For example, the refractive index peak region of the planar nanophotonic microlens 151 can be shifted toward the direction of light incidence. The effective refractive index of the planar nanophotonic microlens 151, which is considered by taking the first layer L1 and the second layer L2 together, can be highest in the shifted refractive index peak region and can gradually decrease toward the outer edge of the refractive index peak region. Furthermore, in the refractive index peak region of the planar nanophotonic microlens 151, the high refractive index nanostructures 151H in the first layer L1 and the second layer L2 can have the same width, but in the region away from the refractive index peak region, the width of the high refractive index nanostructures 151H in the second layer L2 can be smaller than the width of the high refractive index nanostructures 151H in the first layer L1 below it.

[0118] Figures 14 to 16 This is a cross-sectional view illustrating an example of the shape of a planar nanophotonic microlens 151, which also includes a spherical microlens 161, according to another exemplary embodiment. Reference Figure 14 The pixel array 1100 of the image sensor may further include a spherical microlens 161 disposed on a planar nanophotonic microlens 151. Figure 14 A spherical microlens 161 is shown as an example disposed on a planar nanophotonic microlens 151, but multiple spherical microlenses 161 can be arranged two-dimensionally on multiple planar nanophotonic microlenses 151. The planar nanophotonic microlenses 151 and the spherical microlenses 161 can correspond one-to-one with each other. When spherical microlenses 161 are also used, crosstalk occurring at the interfaces between the planar nanophotonic microlenses 151 can be prevented or reduced.

[0119] refer to Figure 14 The refractive index peak regions of the planar nanophotonic microlenses 151 and the optical axes of the spherical microlenses 161, which are located at the center of the pixel array 1100 and correspond to each other, can be aligned to be consistent with each other. The boundaries of the planar nanophotonic microlenses 151 and the boundaries of the spherical microlenses 161, which correspond to each other, can also be consistent with each other.

[0120] refer to Figure 15The refractive index peak region of the planar nanophotonic microlens 151 disposed on the outer edge of the pixel array 1100 may not be aligned with the optical axis of the spherical microlens 161. Furthermore, the spherical microlens 161 disposed on the planar nanophotonic microlens 151 may be offset relative to the planar nanophotonic microlens 151 in the direction of light incidence. For example, at the right edge of the pixel array 1100, the spherical microlens 161 is offset to the left relative to its corresponding planar nanophotonic microlens 151. Therefore, at the outer edge of the pixel array 1100, the spherical microlens 161 may be offset relative to its corresponding planar nanophotonic microlens 151 towards the center of the pixel array 1100.

[0121] Figure 15 The diagram shows that the refractive index peak region of the planar nanophotonic microlens 151 disposed at the outer edge of the pixel array 1100 is offset towards the center of the pixel array 1100. However, when a spherical microlens 161 is also used, the refractive index peak region of the planar nanophotonic microlens 151 disposed at the outer edge of the pixel array 1100 may not be offset. (Reference) Figure 16 The spherical microlens 161 is offset relative to the planar nanophotonic microlens 151 towards the center of the pixel array 1100. The planar nanophotonic microlens 151 below the spherical microlens 161 has a non-offset refractive index peak region. For example, the refractive index peak region of the planar nanophotonic microlens 151 is located at the center of the planar nanophotonic microlens 151. Even if the refractive index peak region of the planar nanophotonic microlens 151 is not offset, incident light can still be incident at the center of the photosensitive unit at a smaller angle due to the offset spherical microlens 161.

[0122] Figures 17 to 20 This is a cross-sectional view showing a pixel array 1100 of an image sensor according to another example embodiment. (Reference) Figures 17 to 20 The pixel array 1100 of the image sensor may further include a transparent dielectric layer 170, the thickness of which increases from the center of the pixel array 1100 to the outer edge.

[0123] refer to Figure 17 The transparent dielectric layer 170 can be disposed between the sensor substrate 110 and the planar nanophotonic microlens array 150, particularly between the color filter layer 140 and the planar nanophotonic microlens array 150. The transparent dielectric layer 170 can have a sloping upper surface so that the thickness of the transparent dielectric layer 170 gradually increases from the center of the pixel array 1100 to the outer edge. Figure 17The upper surface of the transparent dielectric layer 170 is shown to have a flat plate shape with a constant tilt angle; however, the upper surface of the transparent dielectric layer 170 can also have a curved shape with the tilt angle increasing as the CRA increases. The transparent dielectric layer 170 can be disposed over the entire area of ​​the pixel array 1100, but it can also be disposed only over a portion of the outer edge region of the pixel array 1100. For example, the transparent dielectric layer 170 may not be disposed in the central portion of the pixel array 1100 where the sensitivity of the pixels does not decrease significantly due to the CRA.

[0124] Multiple planar nanophotonic microlenses 151 can be arranged at a certain angle on the inclined upper surface of the transparent dielectric layer 170. Because the planar nanophotonic microlenses 151 are arranged at a certain angle, the incident angle of the incident light incident on the planar nanophotonic microlenses 151 can be less than CRA. Specifically, when the transparent dielectric layer 170 has a curved upper surface with an angle that increases with increasing CRA, the incident light can be incident on the entire planar nanophotonic microlens 151 at an almost constant angle.

[0125] refer to Figure 18 A transparent dielectric layer 170 with a tilted upper surface can be disposed on the planar nanophotonic microlens array 150. At the outer edge of the pixel array 1100, due to the tilted upper surface of the transparent dielectric layer 170, the incident angle of incident light incident on the upper surface of the transparent dielectric layer 170 can be less than CRA. Furthermore, because the light is refracted by the transparent dielectric layer 170, the incident angle of incident light incident on the planar nanophotonic microlens 151 located below the transparent dielectric layer 170 can be further reduced.

[0126] refer to Figure 19 and Figure 20 The transparent dielectric layer 170 may have a stepped shape, wherein the thickness of the transparent dielectric layer 170 increases discontinuously from the center of the pixel array 1100 to the outer edge. For example... Figure 19 As shown, a stepped transparent dielectric layer 170 can be disposed between the color filter layer 140 and the planar nanophotonic microlens array 150. Furthermore, as... Figure 20 As shown, a stepped transparent dielectric layer 170 can be disposed on the planar nanophotonic microlens array 150 opposite to the color filter layer 140. Because light is refracted by the transparent dielectric layer 170, the incident angle of the incident light incident on the planar nanophotonic microlens array 150 or the color filter layer 140 can be reduced. Furthermore, Figure 19 and Figure 20 The upper surface of the transparent dielectric layer 170 is shown to be parallel to the horizontal plane, but each stage of the transparent dielectric layer 170 may have a sloping upper surface so that the thickness of the transparent dielectric layer 170 gradually increases from the center portion of the pixel array 1100 to the outer edge.

[0127] Figure 21 This is a plan view illustrating a pixel array 1100 of an image sensor according to another example embodiment. (Reference) Figure 21 The pixel array 1100 may include a spherical microlens array 160 disposed in the central portion and a planar nanophotonic microlens array 150 disposed in the outer edge. In the pixel array 1100, the central portion with a small CRA does not contain the planar nanophotonic microlens 151; instead, only the general spherical microlens array 160 may be provided. For example, only the general spherical microlens array 160 may be disposed in the region where the CRA is less than 30 degrees, and the planar nanophotonic microlens array 150 may be disposed in the region where the CRA is equal to or greater than 30 degrees.

[0128] Figure 22 It shows along Figure 21 The image sensor shown is illustrated with an example cross-sectional view taken from line CC′ of the pixel array 1100. (Reference) Figure 22 The spherical microlens array 160 and the planar nanophotonic microlens array 150 can be arranged on the same plane. For example, the spherical microlens array 160, which includes multiple spherical microlenses 161, and the planar nanophotonic microlens array 150, which includes multiple planar nanophotonic microlenses 151, can both be arranged on the color filter layer 140.

[0129] Figure 23 It shows along Figure 21 Another example cross-sectional view of the pixel array 1100 of the image sensor shown, taken from line CC′. (Reference) Figure 23 The spherical microlens array 160 and the planar nanophotonic microlens array 150 can be arranged on different planes. For example, the planar nanophotonic microlens array 150 can be disposed on the color filter layer 140. In the region of the planar nanophotonic microlens array 150 corresponding to the central portion of the pixel array 1100, the high-refractive-index nanostructure 151H may not exist, but only the low-refractive-index nanostructure 151L may exist. In the central portion of the pixel array 1100, the spherical microlens array 160 can be disposed on the low-refractive-index nanostructure 151L.

[0130] exist Figure 4A In the cross-sectional view of the pixel array 1100 shown, the first color filter 141, the second color filter 142, and the third color filter 143 are arranged sequentially in the horizontal direction as an example, but the embodiment is not limited to this. The arrangement of multiple pixels sensing light of different wavelengths can be implemented in the pixel array 1100 in various ways. Figures 24A to 24C Examples of various pixel arrangements of pixel array 1100 are shown.

[0131] first, Figure 24AThe Bayer pattern commonly used in image sensor 1000 is shown. (Reference) Figure 24A A unit pattern comprises four quadrant regions, and the first to fourth quadrants can be blue pixel B, green pixel G, red pixel R, and green pixel G, respectively. The unit pattern is arranged in a two-dimensional repeating pattern along a first direction (X-direction) and a second direction (Y-direction). For example, in a 2×2 array unit pattern, two green pixels G are arranged diagonally, while a blue pixel B and a red pixel R are arranged diagonally on the other side. Throughout the pixel arrangement, a first row in which multiple green pixels G and multiple blue pixels B are alternately arranged along the second direction, and a second row in which multiple red pixels R and multiple green pixels G are alternately arranged along the first direction, can be repeatedly arranged along the second direction.

[0132] Besides the Bayer pattern, the arrangement of the pixel array 1100 can be varied. For example, refer to... Figure 24B A CYGM layout can be used, where magenta pixels (M), cyan pixels (C), yellow pixels (Y), and green pixels (G) form a unit pattern. (Reference) Figure 24C An RGBW arrangement can be used, where green pixels (G), red pixels (R), blue pixels (B), and white pixels (W) constitute a unit pattern. The unit pattern can have a 3×2 array. Besides the example above, the pixels of the pixel array 1100 can be arranged in various ways according to the color characteristics of the image sensor 1000. In the following description, the pixel array 1100 of the image sensor 1000 will have a Bayer pattern, but the operating principle also applies to other types of pixel arrangements besides the Bayer pattern.

[0133] In the above example embodiments, the use of color filter layer 140 for color separation of incident light has been described. However, a dichroic lens array that uses nanopatterns to converge the color light corresponding to each pixel can be used in conjunction with color filter layer 140, or can be used alone without color filter layer 140. Figure 25A and Figure 25B This is a conceptual diagram illustrating the structure and function of a dichroic lens array 130 according to an example embodiment.

[0134] refer to Figure 25AThe dichroic lens array 130 may include nanopillars NP that differentially change the phase of the incident light Li according to the incident position, and may be divided into a first region 131 and a second region 132. The first region 131 corresponds to a first target region R1 that converges the first wavelength light Lλ1 included in the incident light Li, and the second region 132 corresponds to a second target region R2 that converges the second wavelength light Lλ2 included in the incident light Li. Each of the first region 131 and the second region 132 may include one or more nanopillars NP. The first region 131 and the second region 132 may respectively face the first target region R1 and the second target region R2.

[0135] The dichroic lens array 130 can form different phase distributions of the first wavelength light Lλ1 and the second wavelength light Lλ2 included in the incident light Li, so that the first wavelength light Lλ1 can be focused on the first target region R1 and the second wavelength light Lλ2 can be focused on the second target region R2.

[0136] For example, refer to Figure 25B At a position immediately after the first and second wavelengths of light pass through the dichroic lens array 130 (i.e., at the lower surface of the dichroic lens array 130), the dichroic lens array 130 can give the first wavelength light Lλ1 a first phase distribution PP1 and the second wavelength light Lλ2 a second phase distribution PP2, so that the first wavelength light Lλ1 and the second wavelength light Lλ2 can converge onto their respective first target regions R1 and R2. Specifically, the first wavelength light Lλ1 passing through the dichroic lens array 130 can have a phase distribution PP1, which is maximum at the center of the first region 131 and decreases in the direction away from the center of the first region 131 (i.e., in the direction of the second region 132). This phase distribution can be similar to the phase distribution of light converging to a point through a convex lens (e.g., a microlens with a convex center), and the first wavelength light Lλ1 can converge onto the first target region R1. Furthermore, the second wavelength light Lλ2 passing through the dichroic lens array 130 can have a phase distribution PP2, which is maximum at the center of the second region 132 and decreases in the direction away from the center of the second region 132 (i.e., in the direction of the first region 131), and can converge on the second target region R2.

[0137] Because the refractive index of a material depends on the wavelength of the light that is being transmitted, therefore, Figure 25BAs shown, the dichroic lens array 130 can provide different phase distributions with respect to the first wavelength Lλ1 and the second wavelength Lλ2. For example, because the same material has different refractive indices depending on the wavelength of the light interacting with it, and the phase delay experienced by light passing through the material is also different for each wavelength, different phase distributions can be formed for each wavelength. For example, the refractive index of the first region 131 for the first wavelength Lλ1 can be different from the refractive index of the first region 131 for the second wavelength Lλ2, and the phase delay experienced by the first wavelength Lλ1 passing through the first region 131 and the phase delay experienced by the second wavelength Lλ2 passing through the first region 131 can be different from each other. Therefore, the dichroic lens array 130, designed considering the characteristics of light, can provide different phase distributions with respect to the first wavelength Lλ1 and the second wavelength Lλ2.

[0138] The dichroic lens array 130 may include nanopillars NP arranged according to specific rules, such that the first wavelength light Lλ1 and the second wavelength light Lλ2 have a first phase distribution PP1 and a second phase distribution PP2, respectively. Here, the rules may be applied to parameters such as the shape, size (width and height) of the nanopillars NP, the distance between the nanopillars NP, and their arrangement, and these parameters can be determined according to the phase distribution to be implemented by the dichroic lens array 130.

[0139] The rules for arranging nanopillars NP in the first region 131 and the rules for arranging nanopillars NP in the second region 132 may differ from each other. For example, the shape, size, space and / or arrangement of the nanopillars NP included in the first region 131 may differ from the shape, size, space and / or arrangement of the nanopillars NP included in the second region 132.

[0140] The cross-sectional diameter of the nanopillar NP can have a subwavelength dimension. Here, subwavelength refers to a wavelength smaller than the band of light to be separated. The nanopillar NP can have a dimension smaller than the shorter of the first and second wavelengths. When the incident light Li is visible light, the cross-sectional diameter of the nanopillar NP can have a dimension smaller than 400 nm, 300 nm, or 200 nm. The height of the nanopillar NP can be from 500 nm to 1500 nm and can be greater than its cross-sectional diameter. The nanopillar NP can be a combination of two or more pillars stacked in the height direction (Z direction).

[0141] Nanopillars (NPs) can include materials with a refractive index higher than that of the surrounding material. For example, nanopillars (NPs) can include c-Si, p-Si, a-Si, III-V compound semiconductors (gallium phosphide (GaP), gallium nitride (GaN), gallium arsenide (GaAs), etc.), silicon carbide (SiC), titanium dioxide (TiO2), silicon nitride (SiN), and / or combinations thereof. A nanopillar (NP) with a refractive index different from that of the surrounding material can alter the phase of light passing through it. This is due to a phase retardation caused by the subwavelength shape and size of the nanopillar (NP), and the degree of this phase retardation can be determined by the specific shape and size of the nanopillar (NP), its arrangement, etc. The material surrounding the nanopillar (NP) can include a dielectric material with a refractive index lower than that of the nanopillar (NP), such as SiO2 or air.

[0142] The first and second wavelengths can be in the visible light band, but are not limited to it. The first and second wavelengths can adopt various wavelengths consistent with the arrangement rules of the nanopillars NP. Although two wavelengths are separated and converged, the incident light can be split into three or more directions and converged according to the wavelength.

[0143] In the following text, an example of applying the above-described dichroic lens array 130 to the pixel array 1100 of the image sensor 1000 will be described.

[0144] Figure 26A and Figure 26B This is a schematic cross-sectional view of the pixel array 1100 of an image sensor according to an example embodiment. Figure 27A This is a schematic plan view showing the arrangement of photosensitive units 111, 112, 113, and 114. Figure 27B This is a plan view showing an example arrangement of the nanopillars NP of the dichroic lens array 130, and Figure 27C yes Figure 27B A detailed, enlarged floor plan of a portion.

[0145] refer to Figure 26A and Figure 26B The pixel array 1100 may include: a sensor substrate 110 including a plurality of photosensitive units 111, 112, 113 and 114 for sensing light; a color filter layer 140 disposed on the sensor substrate 110; a planar nanophotonic microlens array 150 disposed on the color filter layer 140; a transparent spacer layer 120 disposed on the planar nanophotonic microlens array 150; and a dichroic lens array 130 disposed on the spacer layer 120.

[0146] like Figure 26A As shown, the first photosensitive unit 111 and the second photosensitive unit 112 can be arranged alternately in the first direction (X direction), and in the Y direction, their positions are... Figure 26A In different cross sections, such as Figure 26B As shown, the third photosensitive unit 113 and the fourth photosensitive unit 114 can be arranged alternately. Figure 26A As shown, the first color filter 141 and the second color filter 142 can also be arranged alternately in the X direction, and in the Y direction, their positions are... Figure 26A In different cross sections, such as Figure 26B As shown, the third color filter 143 and the fourth color filter 141 can be arranged alternately. Figure 27A This shows that when pixel array 1100 has, as Figure 24A The arrangement of photosensitive units 111, 112, 113, and 114 in the illustrated Bayer pattern is used to sense incident light using unit patterns such as the Bayer pattern. For example, the first photosensitive unit 111 and the fourth photosensitive unit 114, arranged facing the first color filter 141, can sense a first wavelength of light; the second photosensitive unit 112, arranged facing the second color filter 142, can sense a second wavelength of light; and the third photosensitive unit 113, arranged facing the third color filter 143, can sense a third wavelength of light. In the following examples, the first wavelength of light is shown as green light, the second wavelength of light as blue light, and the third wavelength of light as red light; the first photosensitive unit 111 and the fourth photosensitive unit 114 can correspond to a green pixel G, the second photosensitive unit 112 can correspond to a blue pixel B, and the third photosensitive unit 113 can correspond to a red pixel R. Separators for separating the units can also be formed at the boundaries between the units.

[0147] A spacer layer 120 can be disposed between the sensor substrate 110 and the dichroic lens array 130 to maintain a constant gap between them. The spacer layer 120 may comprise a material transparent to visible light, such as a dielectric material with a lower refractive index and lower absorption coefficient than the nanopillar NP in the visible light band, such as SiO2, alkyl siloxane spin-coated glass (SOG), etc. The planar nanophotonic microlens array 150 can be considered as a structure buried within the spacer layer 120. The thickness h of the spacer layer 120 can be selected to be within h... t -p≤h≤h t Within the range of +p. In this regard, when the refractive index of the spacer layer 120 with respect to wavelength λ0 is n and the spacing between the photosensitive units is p, the theoretical thickness h of the spacer layer 120 is... t It can be represented by the following equation 1.

[0148] Equation 1

[0149]

[0150] Here, the theoretical thickness h of the spacer layer 120 is... tThis can refer to the focal length at which the dichroic lens array 130 focuses light with a wavelength of λ0 onto the upper surfaces of the photosensitive units 111, 112, 113, and 114. λ0 can be a reference wavelength used to determine the thickness h of the spacer layer 120, and the thickness of the spacer layer 120 can be designed based on 540 nm (i.e., the center wavelength of green light).

[0151] The dichroic lens array 130 may be supported by a spacer layer 120 and may include nanopillars NP that change the phase of the incident light, and a dielectric (e.g., air or SiO2) disposed between the nanopillars NP and having a refractive index lower than that of the nanopillars NP.

[0152] refer to Figure 27B The dichroic lens array 130 can be divided into... Figure 27A The first to fourth photosensitive units 111, 112, 113, and 114 correspond to the first to fourth regions 131, 132, 133, and 134, respectively. The first to fourth regions 131, 132, 133, and 134 can be configured to face the first to fourth photosensitive units 111, 112, 113, and 114, respectively. For example, the first region 131 of the dichroic lens array 130 can be configured to correspond to the first photosensitive unit 111, the second region 132 can be configured to correspond to the second photosensitive unit 112, the third region 133 can be configured to correspond to the third photosensitive unit 113, and the fourth region 134 can be configured to correspond to the fourth photosensitive unit 114. The first to fourth regions 131, 132, 133, and 134 can be arranged two-dimensionally in a first direction (X direction) and a second direction (Y direction), such that a first row in which the first region 131 and the second region 132 are arranged alternately, and a second row in which the third region 133 and the fourth region 134 are arranged alternately, repeating each other. The dichroic lens array 130 may also include a plurality of two-dimensionally arranged unit patterns similar to the photosensitive unit array of the sensor substrate 110, and each unit pattern may include the first to fourth regions 131, 132, 133, and 134 arranged in a 2×2 configuration.

[0153] Figure 26A and Figure 26B The structure shown as an example is a first to fourth region 131, 132, 133 and 134 with the first to fourth photosensitive units 111, 112, 113 and 114 and facing each other in the vertical direction. However, the dichroic lens array 130 can be divided into multiple regions defined in other ways, such as a region for converging light of the first wavelength, a region for converging light of the second wavelength, etc.

[0154] The dichroic lens array 130 may include nanopillars NP with defined size, shape, space, and / or arrangement to separate and focus a first wavelength of light onto a first photosensitive unit 111 and a fourth photosensitive unit 114, a second wavelength of light onto a second photosensitive unit 112, and a third wavelength of light onto a third photosensitive unit 113. The thickness (Z-direction) of the dichroic lens array 130 may be similar to the height of the nanopillars NP and may be from about 500 nm to about 1500 nm.

[0155] refer to Figure 27B The first to fourth regions 131, 132, 133, and 134 may include cylindrical nanopillars NP, each having a circular cross-section. Nanopillars NP with different cross-sectional areas are arranged on the central portion of each of the first to fourth regions 131, 132, 133, and 134. Nanopillars NP may also be arranged at the center of the boundary between pixels and at the intersection of the pixel boundaries. The cross-sectional area of ​​the nanopillars NP arranged at the boundary between pixels may be smaller than the cross-sectional area of ​​the nanopillars NP arranged at the center of the pixel.

[0156] Figure 27C yes Figure 27B A detailed view of the arrangement of nanopillars NPs in a portion of the region (i.e., the first to fourth regions 131, 132, 133, and 134 constituting the unit pattern). Figure 27C In this context, nanopillars NP are designated p1 through p9 based on their specific positions within the unit pattern. (Reference) Figure 27C In the nanopillar NP, the cross-sectional areas of nanopillar p1 at the center of the first region 131 and nanopillar p4 at the center of the fourth region 134 are larger than the cross-sectional areas of nanopillar p2 at the center of the second region 132 and nanopillar p3 at the center of the third region 133, and the cross-sectional area of ​​nanopillar p2 at the center of the second region 132 is larger than the cross-sectional area of ​​nanopillar p3 at the center of the third region 133. However, this is only an example, and nanopillar NPs with various shapes, size spacings, and / or arrangements can be applied as needed.

[0157] The nanopillars NPs included in the first region 131 and the fourth region 134 corresponding to the green pixel G can have different distribution rules in the first direction (X direction) and the second direction (Y direction). For example, the nanopillars NPs arranged in the first region 311 and the fourth region 314 can have different dimensional arrangements in the first direction (X direction) and the second direction (Y direction). Figure 27CAs shown, in the nanopillar NP, the cross-sectional area of ​​nanopillar p5, located at the boundary between the first region 131 and the second region 132 adjacent to the first region 131 in the first direction (X direction), is different from the cross-sectional area of ​​nanopillar p6, located at the boundary between the first region 131 and the third region 133 adjacent to the first region 131 in the second direction (Y direction). Similarly, the cross-sectional area of ​​nanopillar p7, located at the boundary between the fourth region 134 and the third region 133 adjacent to the fourth region 134 in the first direction (X direction), is different from the cross-sectional area of ​​nanopillar p8, located at the boundary between the fourth region 134 and the second region 132 adjacent to the fourth region 134 in the second direction (Y direction).

[0158] The nanopillars NPs arranged in the second region 132 corresponding to the blue pixel B and the third region 133 corresponding to the red pixel R can have a symmetrical distribution pattern in the first direction (X direction) and the second direction (Y direction). For example... Figure 27C As shown, in the nanopillars NP, for the second region 132, the cross-sectional area of ​​nanopillar p5 at its boundary with adjacent pixels in the first direction (X direction) and the cross-sectional area of ​​nanopillar p8 at its boundary with adjacent pixels in the second direction (Y direction) are the same as each other. Similarly, for the third region 133, the cross-sectional area of ​​nanopillar p7 at its boundary with adjacent pixels in the first direction (X direction) and the cross-sectional area of ​​nanopillar p6 at its boundary with adjacent pixels in the second direction (Y direction) are the same as each other.

[0159] Furthermore, the nanopillars p9 at the four corners (i.e., the points where the four regions intersect each other) of each of the first to fourth regions 131, 132, 133 and 134 have the same cross-sectional area.

[0160] The above distribution is caused by the pixel arrangement in the Bayer pattern. The adjacent pixels of blue pixel B and red pixel R in the first direction (X direction) and the second direction (Y direction) are green pixels G. However, the adjacent pixel of green pixel G corresponding to the first region 131 in the first direction (X direction) is blue pixel B, and the adjacent pixel of green pixel G in the second direction (Y direction) is red pixel R. Furthermore, the adjacent pixel of green pixel G corresponding to the fourth region 134 in the first direction (X direction) is red pixel R, and the adjacent pixel of green pixel G in the second direction (Y direction) is blue pixel B. Additionally, the green pixel G corresponding to the first region 131 and the fourth region 134 is adjacent to the same pixel (e.g., green pixel G) in each of the four diagonal directions; the blue pixel B corresponding to the second region 132 is adjacent to the same pixel (e.g., red pixel R) in each of the four diagonal directions; and the red pixel R corresponding to the third region 133 is adjacent to the same pixel (e.g., blue pixel B) in each of the four diagonal directions. Therefore, in the second region 132 and the third region 133 corresponding to the blue pixel B and the red pixel R respectively, the nanopillars NP can be arranged in a four-fold symmetric form, and in the first region 131 and the fourth region 134 corresponding to the green pixel G, the nanopillars NP can be arranged in a two-fold symmetric form. Specifically, the first region 131 and the fourth region 134 are rotated 90° relative to each other.

[0161] Figure 27B and Figure 27C The nanopillars NP have a symmetrical circular cross-sectional shape. However, some nanopillars with asymmetrical cross-sectional shapes may be included. For example, the first region 131 and the fourth region 134 corresponding to the green pixel G can use nanopillars with asymmetrical cross-sectional shapes having different widths in the first direction (X direction) and the second direction (Y direction), and the second region 132 and the third region 133 corresponding to the blue pixel B and the red pixel R can use nanopillars with symmetrical cross-sectional shapes having the same width in the first direction (X direction) and the second direction (Y direction).

[0162] The arrangement rule of the dichroic lens array 130 is an example of achieving the following phase distribution, wherein light with a first wavelength is separated and converged onto the first photosensitive unit 111 and the fourth photosensitive unit 114, light with a second wavelength is separated and converged onto the second photosensitive unit 112, and light with a third wavelength is separated and converged onto the third photosensitive unit 113, but the arrangement rule is not limited to the pattern shown.

[0163] Figure 28A Show along Figure 27B Line II′ passes through the dichroic lens array 130, where the phase distributions of the first and second wavelength light are PP1 and PP2. Figure 28B The phase of the first wavelength light passing through the dichroic lens array 130 is shown at the center of the first to fourth regions 131, 132, 133 and 134, and... Figure 28C The phase of the second wavelength light passing through the dichroic lens array 130 is shown at the center of the first to fourth regions 131, 132, 133 and 134. Figure 28A The phase distributions PP1 and PP2 of the first and second wavelength light shown are compared with the reference. Figure 25B The phase distributions of the first and second wavelengths of light described are the same for PP1 and PP2.

[0164] refer to Figure 28A and Figure 28B The first wavelength light passing through the dichroic lens array 130 may have a first phase distribution PP1, which is maximum at the center of the first region 131 and decreases in the direction away from the center of the first region 131. For example, at a position immediately after passing through the dichroic lens array 130 (at the lower surface of the dichroic lens array 130 or the upper surface of the spacer layer 120), the phase of the first wavelength may be maximum at the center of the first region 131, gradually decrease in a concentric circle form away from the center of the first region 131, be minimum at the center of the second region 132 and the third region 133 in the X and Y directions, and be minimum at the contact point between the first region 131 and the fourth region 134 in the diagonal direction. When the phase of light of the first wavelength emitted from the center of the first region 131 is determined to be 2π, light with a phase of 0.9π to 1.1π at the centers of the second region 132 and the third region 133, light with a phase of 2π at the center of the fourth region 134, and light with a phase of 1.1π to 1.5π at the contact point between the first region 131 and the fourth region 134 can be emitted. The first phase distribution PP1 does not necessarily indicate that the phase delay of light passing through the center of the first region 131 is the largest. When the phase of light passing through the first region 131 is determined to be 2π, the phase value of light passing through another location (when the phase delay is greater than 2π) can be the value remaining after removing 2nπ, i.e., the distribution of the winding phase. For example, when the phase of light passing through the first region 131 is 2π and the phase of light passing through the center of the second region 132 is 3π, the phase in the second region 132 can be the π remaining after removing 2π (when n=1) from 3π.

[0165] refer to Figure 28A and Figure 28CThe second wavelength light passing through the dichroic lens array 130 can have a phase distribution PP2, which is maximized at the center of the second region 132 and decreases in the direction away from the center of the second region 132. Specifically, immediately after passing through the dichroic lens array 130, the phase of the second wavelength can be maximized at the center of the second region 132, gradually decreases in a concentric circle form away from the center of the second region 132, is minimized at the center of the first region 131 and the fourth region 134 in the X and Y directions, and is minimized at the center of the third region 133 in the diagonal direction. When the phase of the second wavelength light at the center of the second region 132 is 2π, the phase of the second wavelength light at the centers of the first region 131 and the fourth region 134 can be 0.9π to 1.1π, and at the center of the third region 133 can be a value less than π (e.g., 0.2π to 0.9π).

[0166] Figure 28D Showing the incident at Figure 28A and Figure 28B An example of the direction of travel of the first wavelength light in and around the first region 131 of the dichroic lens array 130, and Figure 28E An example of a microlens array equivalent to the dichroic lens array 130 relative to the first wavelength of light is shown.

[0167] like Figure 28D As shown, the first wavelength light incident around the first region 131 is focused onto the first photosensitive unit 111 by the dichroic lens array 130, and the first wavelength light from the first region to the third regions 131, 132, and 133 is incident onto the first photosensitive unit 111. For Figure 28A and Figure 28B The phase distribution of the described first wavelength light is similar to the phase distribution of light passing through a virtual first microlens ML1, which is obtained by connecting the centers of two second regions 132 and two third regions 133 that are adjacent to the first region 131 and face each other along one side. Therefore, as... Figure 28E As shown, the dichroic lens array 130 can be equivalent to an array of multiple first microlenses ML1 arranged around the first region 131 for first wavelength light incident on the first region 131. Because each equivalent first microlens ML1 has a larger area than the corresponding first photosensitive unit 111, not only the first wavelength light incident on the first region 131, but also the first wavelength light incident on the second region 132 and the third region 133 can be focused onto the first photosensitive unit 111. The area of ​​the first microlens ML1 can be 1.2 to 2 times the area of ​​the corresponding first photosensitive unit 111.

[0168] Figure 28F Showing the incident at Figure 28A and Figure 28BAn example of the direction of travel of the second wavelength light in and around the second region 132 of the dichroic lens array 130, and Figure 28G An example of a microlens array equivalent to the dichroic lens array 130 relative to the second wavelength of light is shown.

[0169] The second wavelength of light is emitted by the dichroic lens array 130, as shown below. Figure 28F As shown, light converges onto the second photosensitive unit 112, and second wavelength light from the first to the fourth regions 131, 132, 133, and 134 is incident on the second photosensitive unit 112. (See above reference) Figure 28A and Figure 28C The phase distribution of the described second wavelength light is similar to the phase distribution of light passing through a virtual second microlens ML2, which is obtained by connecting the centers of four third regions 133 adjacent to the second region 132 and whose vertices face each other. Therefore, as... Figure 28G As shown, the dichroic lens array 130 can be equivalent to an array of multiple second microlenses ML2 arranged based on the second region 132 for the second wavelength of light. Because each second microlens ML2 is larger than the corresponding second photosensitive unit 112, not only the second wavelength light incident along the direction of the second photosensitive unit 112, but also the second wavelength light incident along the directions of the first photosensitive unit 111, the third photosensitive unit 113, and the fourth photosensitive unit 114 can be focused onto the second photosensitive unit 112. The area of ​​the second microlens ML2 can be 1.5 to 4 times the area of ​​the corresponding second photosensitive unit 112.

[0170] Figure 29A Show along Figure 27B The phase distributions of the first and third wavelength light, PP4 and PP3, of line II-II′ passing through the dichroic lens array 130. Figure 29B The phase of the third wavelength light passing through the dichroic lens array 130 is shown at the center of the first to fourth regions 131, 132, 133, and 134, and... Figure 29C The phase of the first wavelength light passing through the dichroic lens array 130 is shown at the center of the first to fourth regions 131, 132, 133 and 134.

[0171] refer to Figure 29A and Figure 29BThe third wavelength light passing through the dichroic lens array 130 can have a third phase distribution PP3 similar to the phase distribution of the second wavelength light in the second region 132 described above. The phase distribution PP3 can be maximum at the center of the third region 133 and decrease in the direction away from the center of the third region 133. Specifically, immediately after passing through the dichroic lens array 130, the phase of the third wavelength can be maximum at the center of the third region 133, gradually decrease in a concentric circle manner away from the center of the third region 133, be minimum at the center of the first region 131 and the fourth region 134 in the X and Y directions, and be minimum at the center of the second region 132 in the diagonal direction. When the phase of the third wavelength light at the center of the third region 133 is 2π, the phase of the third wavelength light at the centers of the first region 131 and the fourth region 134 can be 0.9π to 1.1π, and at the center of the second region 132 can be a value less than π (approximately 0.2π to 0.9π).

[0172] Figure 29D Showing the incident at Figure 29A and Figure 29B An example of the direction of travel of the third wavelength light in and around the third region 133 of the dichroic lens array 130, and Figure 29E An example of a microlens array equivalent to the dichroic lens array 130 relative to the third wavelength of light is shown.

[0173] like Figure 29D As shown, the third wavelength light is focused onto the third photosensitive unit 113 by the dichroic lens array 130, and the third wavelength light from the first to the fourth regions 131, 132, 133 and 134 is incident on the third photosensitive unit 113. (See above reference...) Figure 29A and Figure 29B The phase distribution of the described third wavelength light is similar to the phase distribution of light passing through a virtual third microlens ML3, which is obtained by connecting the centers of four second regions 132 adjacent to the third region 133 and whose vertices face each other. Therefore, as... Figure 29E As shown, the dichroic lens array 130 can be equivalent to an array of multiple third microlenses ML3 arranged around the third photosensitive unit 113 for the third wavelength of light. Because the area of ​​each third microlens ML3 is larger than the area of ​​the corresponding third photosensitive unit 113, not only the third wavelength light incident along the direction of the third photosensitive unit 113, but also the third wavelength light incident along the directions of the first photosensitive unit 111, the second photosensitive unit 112, and the fourth photosensitive unit 114 can be converged onto the third photosensitive unit 113. The area of ​​the third microlens ML3 can be 1.5 to 4 times the area of ​​the corresponding third photosensitive unit 113.

[0174] refer to Figure 29A and Figure 29C The first wavelength light incident around the fourth region 134 can have a fourth phase distribution PP4 similar to the phase distribution of the first wavelength light with respect to the first region 131 described above. This phase distribution can be maximum at the center of the fourth region 134 and decrease in the direction away from the center of the fourth region 134. At the position immediately after passing through the dichroic lens array 130, the phase of the first wavelength light with respect to the fourth region 134 can be maximum at the center of the fourth region 134, gradually decrease in a concentric circle manner away from the center of the fourth region 134, be minimum at the center of the second region 132 and the third region 133 in the X and Y directions, and be minimum at the point of contact between the first region 131 and the fourth region 134 in the diagonal direction. When the phase of the first wavelength light is 2π at the center of the fourth region 134, the phase of the first wavelength light can be 0.9π to 1.1π at the centers of the second region 132 and the third region 133, 2π at the center of the first region 131, and 1.1π to 1.5π at the point of contact between the first region 131 and the fourth region 134.

[0175] Figure 29F Showing the incident at Figure 29A and Figure 29B An example of the direction of travel of the first wavelength light in and around the fourth region 134 of the dichroic lens array 130, and Figure 29G An example of a microlens array equivalent to the dichroic lens array 130 relative to the first wavelength light is shown. The first wavelength light is focused onto two photosensitive units (i.e., the first photosensitive unit 111 and the fourth photosensitive unit 114), and the phase distribution and direction of travel of the first wavelength light incident on the fourth region 134 are similar to those of the first wavelength light incident on the first region 131, so redundant descriptions are omitted.

[0176] refer to Figure 29F The first wavelength light incident around the fourth region 134 is converged to the fourth photosensitive unit 114 by the dichroic lens array 130, and the first wavelength light from the second region to the fourth regions 132, 133 and 134 is incident on the fourth photosensitive unit 114. Figure 29G As shown, the dichroic lens array 130 can be equivalent to an array of multiple fourth microlenses ML4 arranged based on the fourth photosensitive unit 114 for the first wavelength light incident around the fourth region 134.

[0177] The dichroic lens array 130 works efficiently for light incident within a specific angular range, but its dichroic performance may deteriorate when the incident angle deviates from that range. Therefore, the arrangement shape of the nanopillars of the dichroic lens array 130 can be designed differently depending on the CRA of the incident light, which varies according to the position on the pixel array 1100. Figures 30A to 30CThis is a planar view showing how the arrangement of the nanopillars NPs of the dichroic lens array 130 changes according to their positions on the pixel array 1100. Specifically, Figure 30A The location of the nanopillars NP arranged in the central portion of the pixel array 1100 is shown. Figure 30B The locations of the nanopillars NP arranged between the center and the edge of the pixel array 1100 are shown, and Figure 30C The location of the nanopillars NP arranged at the edge of the pixel array 1100 is shown. Figures 30A to 30C It is not intended to restrict the specific arrangement of nanopillars NP, but is only used to conceptually illustrate how the relative positions of nanopillars NP change depending on their positions on the pixel array 1100.

[0178] like Figures 30A to 30C As shown, from the center of the pixel array 1100 to its edge, the first, second, third, and fourth regions of the dichroic lens array 130 can be offset and configured to move further and further away from their corresponding pixels or photosensitive units. For example, at the center of the pixel array 1100, the center of the dichroic lens array 130, or the center of the sensor substrate 110, the positions of the first, second, third, and fourth regions of the dichroic lens array 130 can coincide with the positions of their respective corresponding green, blue, red, and green pixels (or the positions of their respective corresponding photosensitive units). As the first, second, third, and fourth regions move further away from the center of the pixel array 1100, the center of the dichroic lens array 130, or the center of the sensor substrate 110, the first, second, third, and fourth regions of the dichroic lens array 130 can be offset and configured to move further and further away from their respective corresponding green, blue, red, and green pixels (or the positions of their respective corresponding photosensitive units). The degree of offset of the first, second, third, and fourth regions of the dichroic lens array 130 can be determined by the CRA of the light incident on the dichroic lens array 130. Specifically, at the outer edge of the pixel array 1100, the outer edge of the dichroic lens array 130, or the outer edge of the sensor substrate 110, the first, second, third, and fourth regions of the dichroic lens array 130 can be offset relative to their respective corresponding first, second, third, and fourth photosensitive units towards the center of the pixel array 1100.

[0179] According to the example embodiment, the central portion of the pixel array 1100 has been described as the actual central portion of the pixel array 1100. Since the pixel array 1100 includes a planar nanophotonic microlens array 150, a dichroic lens array 130, and a sensor substrate 110 arranged facing each other, the central portion of the pixel array 1100 can also be the central portion of the planar nanophotonic microlens array 150, the central portion of the dichroic lens array 130, or the central portion of the sensor substrate 110. Similarly, in the following, the outer edge / edge of the pixel array 1100 can refer to the outer edge / edge of the planar nanophotonic microlens array 150, the outer edge / edge of the dichroic lens array 130, or the outer edge / edge of the sensor substrate 110.

[0180] Figure 31 This is a cross-sectional view illustrating the structure of a pixel array 1100 of an image sensor according to another example embodiment. (Reference) Figure 31 The pixel array 1100 differs from the example embodiment described above in that it includes a dichroic lens array 130 having nanopillars NP stacked in two levels. The nanopillars NP may include a first nanopillar NP1 disposed on the spacer layer 120, and a second nanopillar NP2 disposed on the first nanopillar NP1. The second nanopillar NP2 may be offset relative to the first nanopillar NP1 along the direction of light tilt. For example, when light incident on the dichroic lens array 130 is tilted from right to left, the second nanopillar NP2 may be offset to the right relative to the first nanopillar NP1. When light incident on the dichroic lens array 130 is tilted from left to right, the second nanopillar NP2 may be offset to the left relative to the first nanopillar NP1.

[0181] Considering the CRA of the light incident on the pixel array 1100, the second nanopillar NP2 can also be offset relative to the first nanopillar NP1 towards the center of the pixel array 1100. For example, from the center of the pixel array 1100 to the left edge, the second nanopillar NP2 can be offset more to the right relative to the first nanopillar NP1, and from the center of the pixel array 1100 to the right edge, the second nanopillar NP2 can be offset more to the left relative to the first nanopillar NP1.

[0182] Similarly, the third region 133 and the fourth region 134 of the dichroic lens array 130 are offset toward the center of the pixel array 1100 relative to their respective corresponding red pixels (or third photosensitive units 113) and green pixels (or fourth photosensitive units 114). For example, from the center of the pixel array 1100 to the left edge, the third region 133 and the fourth region 134 of the dichroic lens array 130 may be offset further to the right relative to their respective corresponding red and green pixels. The first region and the second region arranged in another section of the dichroic lens array 130 may also be offset toward the center of the pixel array 1100 relative to their respective corresponding green pixels (or first photosensitive units) and blue pixels (or second photosensitive units).

[0183] Specifically, the third region 133 and the fourth region 134 of the dichroic lens array 130 can be offset so that red light and green light converge on the central portions of the third photosensitive unit 113 and the fourth photosensitive unit 114, respectively, corresponding to the third region 133 and the fourth region 134. The offset distance of the third region 133 and the fourth region 134 of the dichroic lens array 130 can be determined, for example, by the following equation 2.

[0184] Equation 2

[0185] s = d × tan(CRA′)

[0186] In Equation 2, d represents the shortest distance or interval between the lower surface of the dichroic lens array 130 and the upper surface of the sensor substrate 110, and CRA' represents the incident angle of the light incident on the sensor substrate 110. Furthermore, CRA' can be determined according to the following Equation 3.

[0187] Equation 3

[0188] CRA′=sin -1 (sin CRA×n)

[0189] In Formula 3, CRA is the incident angle of light incident on the dichroic lens array 130, and n represents the average refractive index of the material disposed between the dichroic lens array 130 and the sensor substrate 110. Therefore, the distances by which the third region 133 and the fourth region 134 of the dichroic lens array 130 and the pixels corresponding to the third region 133 and the fourth region 134 are offset can be determined based on the incident angle of light incident on the dichroic lens array 130 and the average refractive index of the material disposed between the dichroic lens array 130 and the sensor substrate 110.

[0190] Figure 32This is a cross-sectional view illustrating a schematic structure of the pixel array 1100 of an image sensor 1000 according to another example embodiment. When the dichroic lens array 130 is used, the light utilization efficiency of the image sensor 1000 is improved due to the reduced loss caused by the color filter layer 140. Furthermore, high color purity can be achieved when the dichroic lens array 130 and the color filter layer 140 are used together. If sufficient color separation is generated by the dichroic lens array 130 to achieve high color purity, then... Figure 32 As shown, color filter layer 140 can be omitted. Figure 32 The configuration shown is the same as Figure 31 The configuration shown is the same, but the color filter layer 140 is omitted.

[0191] Figure 33 This is a planar view illustrating an example of the offset morphology of nanopillars NP1 and NP2 arranged in a two-dimensional array of dichroic lenses 130. (Reference) Figure 33 At the center of the pixel array 1100, the second nanopillar NP2 of the dichroic lens array 130 is not offset relative to the first nanopillar NP1. At the outer edge of the pixel array 1100, the second nanopillar NP2 of the dichroic lens array 130 is offset relative to the first nanopillar NP1 towards the center of the pixel array 1100. Therefore, the total area of ​​the dichroic lens array 130 can be smaller than the total area of ​​the pixel array 1100 or the total area of ​​the sensor substrate 110. The total area of ​​the dichroic lens array 130 can also be substantially equal to the total area of ​​the planar nanophotonic microlens array 150.

[0192] Figure 27B The dichroic lens array 130 shown is merely an example, and various types of dichroic lens arrays 130 can be designed according to the color characteristics of the image sensor, pixel pitch, incident angle of incident light, etc. The dichroic lens array 130 has been described as comprising a plurality of cylindrical nanopillars NP spaced apart from each other, but the embodiments are not limited thereto.

[0193] Figure 34A and Figure 34B This is a plan view illustrating examples of unit patterns of dichroic lens arrays 130′ and 130″, respectively, applicable to an image sensor of the Bayer pattern type according to another example embodiment. (Reference) Figure 34A The dichroic lens array 130' may include first to fourth regions 131', 132', 133', and 134' arranged in a 16×16 rectangular pattern in digital binary form. The unit pattern of the dichroic lens array 130' has a 32×32 rectangular shape. (Reference) Figure 34B Each of the first to fourth regions 131″, 132″, 133″, and 134″ of the dichroic lens array 130″ is presented as a continuous, undigitized curve. Applied to... Figure 34A and Figure 34B The rules for the first to fourth regions 131′, 132′, 133′, 134′, 131″, 132″, 133″ and 134″ of the dichroic lens arrays 130′ and 130″ shown are the same as those applied to the first to fourth regions 131, 132, 133 and 134 of the dichroic lens array 130.

[0194] The dichroic lens arrays 130′ and 130″ that satisfy the phase distribution and performance of the dichroic lens array 130 described above can be automatically designed through various types of computer simulations. For example, the structures of the first to fourth regions 131′, 132′, 133′, 134′, 131″, 132″, 133″, and 134″ can be optimized through natural heuristic algorithms such as genetic algorithms, particle swarm optimization algorithms, ant colony optimization algorithms, or reverse design based on adjoint optimization algorithms.

[0195] When designing dichroic lens arrays 130′ and 130″, while evaluating the performance of candidate dichroic lens arrays based on evaluation factors (such as dichroic spectrum, optical efficiency, signal-to-noise ratio, etc.), the first to fourth patterns of the first to fourth regions 131′, 132′, 133′, 134′, 131″, 132″, 133″, and 134″ can be optimized. For example, the patterns of the first to fourth regions 131′, 132′, 133′, 134′, 131″, 132″, 133″, and 134″ can be optimized by minimizing the sum of the differences from the target value of each evaluation factor when the target value of each evaluation factor is predetermined. According to another example embodiment, the performance can be indexed for each evaluation factor, and the first to fourth regions 131′, 132′, 133′, 134′, 131″, 132″, 133″, and 134″ can be optimized so that the value representing the performance can be maximized.

[0196] In the image sensor 1000 described above, which includes dichroic lens arrays 130, 130′, and 130″, light loss caused by color filters (e.g., organic color filters) is minimal, thus providing sufficient light intensity to the pixels even when the pixel size is reduced. Therefore, it is possible to manufacture ultra-high resolution, ultra-small size, and high sensitivity image sensors with hundreds of millions or more pixels. Such ultra-high resolution, ultra-small size, and high sensitivity image sensors can be used in various high-performance optical devices or high-performance electronic devices. For example, electronic devices may include, but are not limited to, smartphones, personal digital assistants (PDAs), laptops, personal computers (PCs), various portable devices, surveillance cameras, medical cameras, automobiles, the Internet of Things (IoT), and other mobile or non-mobile computing devices.

[0197] In addition to the image sensor 1000, the electronic device may also include a processor, such as an application processor (AP), to control the image sensor, drive an operating system or application, control multiple hardware or software components, and perform various data processing and operations. The processor may also include a graphics processing unit (GPU) and / or an image signal processor. When the processor includes an image signal processor, images (or videos) acquired by the image sensor can be stored and / or output using the processor.

[0198] Figure 35 This is a block diagram illustrating an example of an electronic device 1801 including an image sensor 1000 according to an exemplary embodiment. (See reference...) Figure 35 In network environment 1800, electronic device 1801 can communicate with another electronic device 1802 via a first network 1898 (such as a short-range wireless communication network), or with another electronic device 1804 and / or server 1808 via a second network 1899 (such as a long-range wireless communication network). Electronic device 1801 can communicate with electronic device 1804 via server 1808. Electronic device 1801 may include a processor 1820, a memory 1830, an input device 1850, a sound output device 1855, a display device 1860, an audio module 1870, a sensor module 1876, an interface 1877, a haptic module 1879, a camera module 1880, a power management module 1888, a battery 1889, a communication module 1890, a user identification module 1896, and / or an antenna module 1897. Electronic device 1801 may omit some components (such as the display device 1860), or may include other components. One or more components of the assembly can be implemented as integrated circuits. For example, sensor module 1876 (fingerprint sensor, iris sensor, illuminance sensor, etc.) can be embedded in display device 1860 (display, etc.).

[0199] Processor 1820 can be configured to execute software (program 1840, etc.) to control one or more components (hardware or software components) of electronic device 1801, components connected to processor 1820, and perform various data processing or calculations. As part of data processing or calculations, processor 1820 can be configured to load commands and / or data received from other components (sensor module 1876, communication module 1890, etc.) into volatile memory 1832, process the commands and / or data stored in volatile memory 1832, and store the result data in non-volatile memory 1834. Processor 1820 may include a main processor 1821 (central processing unit (CPU), application processor (AP), etc.) and a secondary processor 1823 (graphics processing unit (GPU), image signal processor, sensor hub processor, communication processor, etc.) that can operate independently of or with the main processor 1821. The secondary processor 1823 can use less power than the main processor 1821 and can perform specified functions.

[0200] When the main processor 1821 is in an inactive state (sleep state), the auxiliary processor 1823 can be responsible for controlling the operation of functions and / or states related to one or more components of the electronic device 1801 (display device 1860, sensor module 1876, communication module 1890, etc.). Alternatively, when the main processor 1821 is in an active state (application execution state), the auxiliary processor 1823 can perform the same operation together with the main processor 1821. The auxiliary processor 1823 (image signal processor, communication processor, etc.) can be implemented as part of other functionally related components (camera module 1880, communication module 1890, etc.).

[0201] The memory 1830 may store various data required by the components of the electronic device 1801 (processor 1820, sensor module 1876, etc.). This data may include, for example, input and / or output data of software (program 1840, etc.) and software-related commands. The memory 1830 may include volatile memory 1832 and / or non-volatile memory 1834.

[0202] Program 1840 may be stored as software in memory 1830 and may include operating system 1842, middleware 1844 and / or application 1846.

[0203] Input device 1850 can receive commands and / or data from outside electronic device 1801 for use by components of electronic device 1801 (processor 1820, etc.). Input device 1850 may include a microphone, mouse, keyboard, and / or digital pen (stylus, etc.).

[0204] The sound output device 1855 can output sound signals to the outside of the electronic device 1801. The sound output device 1855 may include a speaker and / or a handset. The speaker can be used for general purposes such as multimedia playback or recording playback, and the handset can be used to receive incoming calls. The handset can be coupled to the speaker as part of the speaker or can be implemented as a separate device.

[0205] Display device 1860 can visually provide information to the outside of electronic device 1801. Display device 1860 may include a display, a holographic device, or control circuitry for controlling a projector and related devices. Display device 1860 may include touch circuitry configured to sense touch operations and / or sensor circuitry (pressure sensor, etc.) configured to measure the intensity of the force generated by the touch operation.

[0206] Audio module 1870 can convert sound into electrical signals, or electrical signals into sound. Audio module 1870 can acquire sound via input device 1850, or output sound via sound output device 1855 and / or speakers and / or headphones of electronic devices (electronic devices 1802, etc.) directly or wirelessly connected to electronic device 1801.

[0207] Sensor module 1876 can sense the operating state (power, temperature, etc.) of electronic device 1801 or the external environmental state (user state, etc.), and can generate electrical signals and / or data values ​​corresponding to the sensed state. Sensor module 1876 may include gesture sensors, gyroscope sensors, atmospheric sensors, magnetic sensors, accelerometers, grip sensors, proximity sensors, color sensors, infrared (IR) sensors, biometric sensors, temperature sensors, humidity sensors, and / or illuminance sensors.

[0208] Interface 1877 may support one or more specified protocols for electronic device 1801 to connect directly or wirelessly to another electronic device (electronic device 1802, etc.). Interface 1877 may include a High Definition Multimedia Interface (HDMI) interface, a Universal Serial Bus (USB) interface, an SD card interface, and / or an audio interface.

[0209] Connection terminal 1878 may include a connector through which electronic device 1801 can be physically connected to another electronic device (electronic device 1802, etc.). Connection terminal 1878 may include an HDMI connector, a USB connector, an SD card connector, and / or an audio connector (headphone connector, etc.).

[0210] The haptic module 1879 can convert electrical signals into mechanical stimuli (vibration, motion, etc.) or electrical stimuli that can be recognized by a user through touch or motion sensation. The haptic module 1879 may include a motor, a piezoelectric device, and / or an electrical stimulation device.

[0211] Camera module 1880 can capture still images and video. Camera module 1880 may include: a lens assembly comprising one or more lenses; Figure 1 The image sensor 1000, image signal processor, and / or flash are included. The lens assembly included in the camera module 1880 can collect light emitted from the object whose image is to be captured.

[0212] The power management module 1888 can manage the power supplied to the electronic device 1801. The power management module 1888 can be implemented as part of a power management integrated circuit (PMIC).

[0213] Battery 1889 can power components of electronic device 1801. Battery 1889 may include a non-rechargeable main battery, a rechargeable secondary battery, and / or a fuel cell.

[0214] Communication module 1890 can support the establishment of (wired) and / or wireless communication channels between electronic device 1801 and other electronic devices (electronic device 1802, electronic device 1804, server 1808, etc.), and perform communication through the established communication channels. Communication module 1890 may include one or more communication processors that operate independently of processor 1820 (application processor, etc.) and support direct and / or wireless communication. Communication module 1890 may include wireless communication module 1892 (cellular communication module, short-range wireless communication module, Global Navigation Satellite System (GNSS) communication module, etc.) and / or wired communication module 1894 (local area network (LAN) communication module, power line communication module, etc.). Corresponding communication modules among these communication modules can communicate with other electronic devices through a first network 1898 (a short-range wireless communication network such as Bluetooth, WiFi Direct, or Infrared Data Association (IrDA)) or a second network 1899 (a long-range communication network such as a cellular network, the Internet, or computer network (LAN, WAN, etc.). The various types of communication modules described above can be integrated into a single component (a single chip, etc.) or implemented as multiple components (multiple chips). The wireless communication module 1892 can identify and authenticate the electronic device 1801 in the first network 1898 and / or the second network 1899 by using user information (International Mobile Subscriber Identity (IMSI), etc.) stored in the user identification module 1896.

[0215] Antenna module 1897 can transmit signals and / or power to or from external sources (other electronic devices, etc.). The antenna may include a transmitter comprising conductive patterns formed on a substrate (printed circuit board (PCB), etc.). Antenna module 1897 may include one or more antennas. When antenna module 1897 includes multiple antennas, appropriate antennas suitable for communication methods used in communication networks such as first network 1898 and / or second network 1899 can be selected. Through the selected antennas, signals and / or power can be transmitted or received between communication module 1890 and other electronic devices. In addition to the antennas, other components (radio frequency integrated circuits (RFICs), etc.) may be included in antenna module 1897.

[0216] One or more components of the electronic device 1801 can be connected to each other and exchange signals (commands, data, etc.) through communication methods (bus, general purpose input and output (GPIO), serial peripheral bus (SPI), mobile industrial processor interface (MIPI), etc.) executed in peripheral devices.

[0217] Commands or data can be sent or received between electronic device 1801 and another external electronic device 1804 via server 1808 connected to the second network 1899. Other electronic devices 1802 and 1804 may be of the same or different type as electronic device 1801. All or some operations performed in electronic device 1801 can be performed by one or more of the other electronic devices 1802, 1804, and 1808. For example, when electronic device 1801 must perform a function or service, instead of directly performing that function or service, it can request one or more other electronic devices to perform part or all of that function or service. The one or more electronic devices receiving the request can perform additional functions or services related to the request and can send the results of the execution back to electronic device 1801. For this purpose, cloud computing, distributed computing, and / or client-server computing technologies can be used.

[0218] Figure 36 It is shown Figure 35 Block diagram of the 1880 camera module. (Reference) Figure 36 The camera module 1880 may include a lens assembly 1910, a flash 1920, and an image sensor 1000 (see [link]). Figure 1The system includes an image stabilizer 1940, a memory 1950 (buffer memory, etc.), and / or an image signal processor 1960. The lens assembly 1910 can collect light emitted from the object being captured as the target of image capture. The camera module 1880 may include multiple lens assemblies 1910, and in this case, the camera module 1880 may include a dual-camera system, a 360-degree camera, or a spherical camera. Some of the multiple lens assemblies 1910 may have the same lens properties (angle of view, focal length, AF, F-number, optical zoom, etc.) or may have different lens properties. The lens assembly 1910 may include a wide-angle lens or a telephoto lens.

[0219] The flash unit 1920 can emit light to enhance light emitted or reflected from an object. The flash unit 1920 may include one or more light-emitting diodes (RGB LEDs, white LEDs, infrared LEDs, ultraviolet LEDs, etc.) and / or a xenon lamp. The image sensor 1000 may be... Figure 1 The image sensor 1000 described herein can acquire an image corresponding to an object by converting light emitted or reflected from an object and transmitted through the lens assembly 1910 into an electrical signal. The image sensor 1000 may include one or more sensors selected from image sensors with different properties (e.g., RGB sensors, black-and-white (BW) sensors, IR sensors, or UV sensors). Each sensor included in the image sensor 1000 may be implemented as a charge-coupled device (CCD) sensor and / or a complementary metal-oxide-semiconductor (CMOS) sensor.

[0220] Image stabilizer 1940 can move one or more lenses or image sensors 1000 included in lens assembly 1910 in a specific direction in response to movement of camera module 1880 or electronic device 1801 including camera module 1880, or control the operating characteristics of image sensor 1000 (adjust readout timing, etc.) to compensate for negative effects caused by movement. Image stabilizer 1940 can use a gyroscope sensor or accelerometer sensor disposed inside or outside camera module 1880 to detect movement of camera module 1880 or electronic device 1801. Image stabilizer 1940 can be implemented in an optical form.

[0221] The memory 1950 can store part or all of the image data acquired by the image sensor 1000 for subsequent image processing operations. For example, when multiple images are acquired at high speed, the acquired raw data (Bayer pattern data, high-resolution data, etc.) can be stored in the memory 1950, only the low-resolution image can be displayed, and then the raw data of the selected (user-selected, etc.) image can be sent to the image signal processor 1960. The memory 1950 can be integrated into the memory 1830 of the electronic device 1801 or can be configured as a separate memory that operates independently.

[0222] Image signal processor 1960 can perform image processing operations on images acquired by image sensor 1000 or image data stored in memory 1950. Image processing may include depth map generation, 3D modeling, panorama generation, feature point extraction, image compositing, and / or image compensation (noise reduction, resolution adjustment, brightness adjustment, blurring, sharpening, softening, etc.). Image signal processor 1960 can perform control (exposure time control, readout timing control, etc.) on components (image sensor 1000, etc.) included in camera module 1880. Images processed by image signal processor 1960 may be stored again in memory 1950 for further processing, or may be provided to external components of camera module 1880 (memory 1830, display device 1860, electronic device 1802, electronic device 1804, server 1808, etc.). Image signal processor 1960 may be integrated into processor 1820 or configured as a separate processor operating independently of processor 1820. When the image signal processor 1960 is configured as a processor separate from the processor 1820, the image processed by the image signal processor 1960 can undergo additional image processing by the processor 1820 and then be displayed by the display device 1860.

[0223] The electronic device 1801 may include a plurality of camera modules 1880 with different attributes or functions. In this case, one of the camera modules 1880 may be a wide-angle camera, and the other camera modules may be telephoto cameras. Similarly, one of the camera modules 1880 may be a front-facing camera, and the other camera modules may be rear-facing cameras.

[0224] The image sensor 1000 according to the example embodiment can be applied to Figure 37 The mobile phone or smartphone shown is 2000. Figure 38 The tablet computer or smart tablet computer 2100 shown is shown. Figure 39 The digital camera or video recorder 2200 shown Figure 40 The laptop computer shown is 2300 or Figure 41The television or smart TV 2400 shown is an example. For instance, a smartphone 2000 or a smart tablet computer 2100 may include multiple high-resolution cameras, each including a high-resolution image sensor. By using high-resolution cameras, depth information of objects in an image can be extracted, image defocus can be adjusted, or objects in an image can be automatically identified.

[0225] The image sensor 1000 can also be applied to Figure 42 The smart refrigerator 2500 shown Figure 43 The surveillance camera 2600 shown Figure 44 The robot 2700 shown Figure 45 Examples include medical cameras such as 2800. For instance, a smart refrigerator 2500 can automatically identify food items in the refrigerator using image sensors and can notify the user via a smartphone about the presence of specific types of food, the types of food placed or removed, etc. A surveillance camera 2600 can also provide ultra-high-resolution images using high sensitivity and allow users to identify objects or people even in dark environments. A robot 2700 can enter disaster or industrial locations inaccessible to humans and provide high-resolution images to users. A medical camera 2800 can provide high-resolution images for diagnosis or surgery and can dynamically adjust its field of view.

[0226] Image sensors can also be applied to Figure 46 The vehicle 2900 is shown. The vehicle 2900 may include a plurality of vehicle cameras 2910, 2920, 2930, and 2940 arranged in various locations. Each of the vehicle cameras 2910, 2920, 2930, and 2940 may include an image sensor according to an embodiment. The vehicle 2900 can provide the driver with various information about the interior of the vehicle 2900 or the surroundings of the vehicle 2900 by using the plurality of vehicle cameras 2910, 2920, 2930, and 2940, and can provide the driver with information necessary for autonomous driving by automatically recognizing objects or people in the images.

[0227] It should be understood that the exemplary embodiments described herein should be considered only in a descriptive sense and not for limiting purposes. The description of features or aspects in each exemplary embodiment should typically be considered as other similar features or aspects that may be used in other embodiments. Although exemplary embodiments have been described with reference to the accompanying drawings, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope defined by the appended claims and their equivalents.

Claims

1. An image sensor, comprising: A sensor substrate, comprising a plurality of photosensitive units configured to sense light; as well as A planar nanophotonic microlens array includes multiple planar nanophotonic microlenses, each having a nanopattern structure configured to converge light onto a corresponding photosensitive unit within the multiple photosensitive units. Each of the plurality of planar nanophotonic microlenses comprises: a high-refractive-index nanostructure comprising a first dielectric material having a first refractive index, and a low-refractive-index nanostructure comprising a second dielectric material having a second refractive index lower than the first refractive index. Among the plurality of planar nanophotonic microlenses, the effective refractive index of each planar nanophotonic microlens is the largest in the refractive index peak region of each planar nanophotonic microlens, and gradually decreases towards the outer edge away from the refractive index peak region. The effective refractive index corresponds to the ratio of the high-refractive-index nanostructure to the low-refractive-index nanostructure. In this configuration, each of the plurality of planar nanophotonic microlenses located at the outer edge of the planar nanophotonic microlens array is offset toward the central portion of the planar nanophotonic microlens array. Each of the plurality of planar nanophotonic microlenses comprises a first layer and a second layer disposed on the first layer, wherein the patterns of high-refractive-index nanostructures and low-refractive-index nanostructures in the first layer are different from the patterns of high-refractive-index nanostructures and low-refractive-index nanostructures in the second layer. Specifically, in the region outside the refractive index peak region of each of the plurality of planar nanophotonic microlenses, the width of the high refractive index nanostructure in the second layer is smaller than the width of the high refractive index nanostructure in the first layer, and In this process, the width of the high-refractive-index nanostructure in the second layer gradually decreases from the peak refractive index region toward the outer edge that deviates from the peak refractive index region.

2. The image sensor of claim 1, wherein, At the central portion of the planar nanophotonic microlens array, the boundaries between the plurality of planar nanophotonic microlenses coincide with the boundaries between the corresponding photosensitive units.

3. The image sensor of claim 1, wherein, The distance by which each of the plurality of planar nanophotonic microlenses located at the outer edge of the planar nanophotonic microlens array is offset toward the center portion of the planar nanophotonic microlens array increases as the distance of each of the plurality of planar nanophotonic microlenses from the center portion of the planar nanophotonic microlens array increases.

4. The image sensor of claim 1, wherein, The refractive index peak region of each planar nanophotonic microlens in the plurality of planar nanophotonic microlenses is located at the central portion of the planar nanophotonic microlens array.

5. The image sensor according to claim 4, wherein, The refractive index peak region of each planar nanophotonic microlens located at the outer edge of the planar nanophotonic microlens array is offset toward the center portion of the planar nanophotonic microlens array.

6. The image sensor according to claim 5, wherein, The refractive index peak region of each of the plurality of planar nanophotonic microlenses at the outer edge of the planar nanophotonic microlens array is offset toward the center portion of the planar nanophotonic microlens array by a distance that increases as the distance of each of the plurality of planar nanophotonic microlenses from the center portion of the planar nanophotonic microlens array increases.

7. The image sensor according to claim 1, wherein, Each of the plurality of planar nanophotonic microlenses comprises: A first region having a first effective refractive index; The second region is configured to be adjacent to the first region and have a second effective refractive index lower than the first effective refractive index of the first region; and The third region is configured to be adjacent to the second region and have a third effective refractive index that is lower than the second effective refractive index of the second region. The first region, the second region, and the third region are arranged in a concentric circle shape.

8. The image sensor according to claim 1, wherein, Each of the plurality of planar nanophotonic microlenses located at the central portion of the planar nanophotonic microlens array has an effective refractive index distribution that is symmetrical about the central portion, and each of the plurality of planar nanophotonic microlenses located at the outer edge of the planar nanophotonic microlens array has an effective refractive index distribution that is asymmetrical about the central portion.

9. The image sensor according to claim 1, wherein, The total area of ​​the plurality of planar nanophotonic microlenses is smaller than the total area of ​​the sensor substrate.

10. The image sensor according to claim 1, wherein, Each of the plurality of planar nanophotonic microlenses comprises a plurality of high-refractive-index nanostructures and a plurality of low-refractive-index nanostructures arranged in a concentric circle shape, and the width of each of the plurality of high-refractive-index nanostructures in the diametrical direction is the largest in the refractive index peak region.

11. The image sensor according to claim 1, wherein, Each of the plurality of planar nanophotonic microlenses comprises: a plurality of high-refractive-index nanostructures having a nanopillar shape, and the proportion of the plurality of high-refractive-index nanostructures is the largest in the refractive index peak region.

12. The image sensor according to claim 1, wherein, Each of the plurality of planar nanophotonic microlenses comprises: a plurality of arc-shaped, high-refractive-index nanostructures separated along the circumferential direction.

13. The image sensor according to claim 1, wherein, Each of the plurality of planar nanophotonic microlenses comprises: a high-refractive-index nanostructure with a plate shape and a plurality of low-refractive-index nanostructures with aperture shapes.

14. The image sensor according to claim 1, wherein, In the refractive index peak region of each of the plurality of planar nanophotonic microlenses, the width of the high refractive index nanostructure in the first layer is the same as the width of the high refractive index nanostructure in the second layer.

15. The image sensor according to claim 1, further comprising: A spherical microlens is disposed on each of the plurality of planar nanophotonic microlenses.

16. The image sensor according to claim 15, wherein, The refractive index peak region of each planar nanophotonic microlens located at the central portion of the planar nanophotonic microlens array is aligned with the optical axis of the corresponding spherical microlens to be consistent with each other.

17. The image sensor according to claim 15, wherein, The spherical microlens at the outer edge of the planar nanophotonic microlens array is offset relative to the corresponding planar nanophotonic microlens towards the center of the planar nanophotonic microlens array.

18. The image sensor according to claim 17, wherein, The refractive index peak region of the planar nanophotonic microlens at the outer edge of the planar nanophotonic microlens array is set at the center of the planar nanophotonic microlens.

19. The image sensor according to claim 1, further comprising: A transparent dielectric layer is disposed between the sensor substrate and the planar nanophotonic microlens array, and the thickness of the transparent dielectric layer increases from the center of the planar nanophotonic microlens array toward the outer edge of the planar nanophotonic microlens array.

20. The image sensor according to claim 19, wherein, The transparent dielectric layer has an inclined upper surface such that the thickness of the transparent dielectric layer gradually increases from the center portion of the planar nanophotonic microlens array toward the outer edge of the planar nanophotonic microlens array, and the plurality of planar nanophotonic microlenses are disposed at a certain angle on the inclined upper surface of the transparent dielectric layer.

21. The image sensor according to claim 19, wherein, The transparent dielectric layer has a stepped shape, wherein the thickness of the transparent dielectric layer increases discontinuously from the central portion of the planar nanophotonic microlens array toward the outer edge of the planar nanophotonic microlens array.

22. The image sensor according to claim 1, further comprising: A transparent dielectric layer is disposed on the planar nanophotonic microlens array, and the thickness of the transparent dielectric layer increases from the center of the planar nanophotonic microlens array toward the outer edge of the planar nanophotonic microlens array.

23. The image sensor according to claim 1, further comprising: A spherical microlens array, comprising multiple spherical microlenses disposed in the central portion of the planar nanophotonic microlens array. The plurality of planar nanophotonic microlenses are not located in the central part of the planar nanophotonic microlens array.

24. The image sensor according to claim 23, wherein, The spherical microlens array and the planar nanophotonic microlens array are arranged on the same plane.

25. The image sensor according to claim 23, wherein, A low-refractive-index nanostructure is disposed in the central portion of the planar nanophotonic microlens array, and the spherical microlens array is disposed on the low-refractive-index nanostructure in the central portion of the planar nanophotonic microlens array.

26. The image sensor according to claim 1, further comprising: A color filter layer disposed on the sensor substrate The color filter layer includes multiple color filters configured to transmit light of a specific wavelength and absorb or reflect light of other wavelengths. The planar nanophotonic microlens array is disposed on the color filter layer.

27. The image sensor according to claim 1, further comprising: A transparent spacer layer is disposed on the planar nanophotonic microlens array; as well as A dichroic lens array is disposed on the transparent spacer layer. The dichroic lens array is configured to change the phase of a first wavelength of light and the phase of a second wavelength of light in the incident light, wherein the first light and the second light are different from each other, so that the first light of the first wavelength and the second light of the second wavelength propagate in different directions, thereby converging the first light of the first wavelength onto a first photosensitive unit among the plurality of photosensitive units, and converging the second light of the second wavelength onto a second photosensitive unit among the plurality of photosensitive units that is different from the first photosensitive unit.

28. An electronic device comprising: An image sensor is configured to convert optical images into electrical signals; as well as The processor is configured to control the operation of the image sensor and to store and output signals generated by the image sensor. The image sensor includes: A sensor substrate, comprising a plurality of photosensitive units configured to sense light; and A planar nanophotonic microlens array includes multiple planar nanophotonic microlenses, each having a nanopattern structure configured to converge light onto a corresponding photosensitive unit within the multiple photosensitive units. Each of the plurality of planar nanophotonic microlenses comprises: a high-refractive-index nanostructure comprising a first dielectric material having a first refractive index, and a low-refractive-index nanostructure comprising a second dielectric material having a second refractive index lower than the first refractive index. Among the plurality of planar nanophotonic microlenses, the effective refractive index of each planar nanophotonic microlens is the largest in the refractive index peak region of each planar nanophotonic microlens, and gradually decreases towards the outer edge away from the refractive index peak region. The effective refractive index corresponds to the ratio of the high-refractive-index nanostructure to the low-refractive-index nanostructure. In this configuration, each of the plurality of planar nanophotonic microlenses located at the outer edge of the planar nanophotonic microlens array is offset toward the central portion of the planar nanophotonic microlens array. Each of the plurality of planar nanophotonic microlenses comprises a first layer and a second layer disposed on the first layer, wherein the patterns of high-refractive-index nanostructures and low-refractive-index nanostructures in the first layer are different from the patterns of high-refractive-index nanostructures and low-refractive-index nanostructures in the second layer. Specifically, in the region outside the refractive index peak region of each of the plurality of planar nanophotonic microlenses, the width of the high refractive index nanostructure in the second layer is smaller than the width of the high refractive index nanostructure in the first layer, and In this process, the width of the high-refractive-index nanostructure in the second layer gradually decreases from the peak refractive index region toward the outer edge that deviates from the peak refractive index region.

29. An image sensor, comprising: A sensor substrate, comprising a plurality of photosensitive units configured to sense light; as well as A planar nanophotonic microlens array includes multiple planar nanophotonic microlenses, each having a nanopattern structure configured to converge light onto a corresponding photosensitive unit within the multiple photosensitive units. Each of the plurality of planar nanophotonic microlenses comprises: a high-refractive-index nanostructure comprising a first dielectric material having a first refractive index, and a low-refractive-index nanostructure comprising a second dielectric material having a second refractive index lower than the first refractive index. Among the plurality of planar nanophotonic microlenses, the effective refractive index of each planar nanophotonic microlens is the largest in the refractive index peak region of each planar nanophotonic microlens, and gradually decreases towards the outer edge away from the refractive index peak region. The effective refractive index corresponds to the ratio of the high-refractive-index nanostructure to the low-refractive-index nanostructure. Among the plurality of planar nanophotonic microlenses, each planar nanophotonic microlens located at the outer edge of the planar nanophotonic microlens array is offset toward the center portion of the planar nanophotonic microlens array, and In this configuration, the refractive index peak region of each planar nanophotonic microlens located at the outer edge of the planar nanophotonic microlens array is offset towards the center of the planar nanophotonic microlens array. Each of the plurality of planar nanophotonic microlenses comprises a first layer and a second layer disposed on the first layer, wherein the patterns of high-refractive-index nanostructures and low-refractive-index nanostructures in the first layer are different from the patterns of high-refractive-index nanostructures and low-refractive-index nanostructures in the second layer. Specifically, in the region outside the refractive index peak region of each of the plurality of planar nanophotonic microlenses, the width of the high refractive index nanostructure in the second layer is smaller than the width of the high refractive index nanostructure in the first layer, and In this process, the width of the high-refractive-index nanostructure in the second layer gradually decreases from the peak refractive index region toward the outer edge that deviates from the peak refractive index region.

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