Image sensor

Abstract

The image sensor 100 includes a photoelectric conversion layer, a color filter layer disposed on the photoelectric conversion layer, a buffer layer 130 disposed on the color filter layer, a meta layer 140, and an antireflection layer 150 non-conformally coated on the meta layer. The meta layer includes a lining layer 142 on the buffer layer and a plurality of upper nanostructures 144 protruding from the lining layer in a direction away from the photoelectric conversion layer. The antireflection layer includes a first portion 151 on the upper surface of the first nanostructure 146 of the upper nanostructure and a second portion 152 on the sidewall of the first nanostructure, and the height H1 of the first portion is greater than the width W1 of the second portion. 【Effect】The antireflection layer is non-conformally coated on the nanostructure of the meta layer, further reducing reflection and enhancing the optical effect.

Description

Technical Field

[0001] The present disclosure relates to an image sensor. More specifically, the present disclosure relates to an image sensor having an anti-reflection structure.

Background Art

[0002] With the development of semiconductor devices, there is an increasing demand for technologies of complementary metal-oxide-semiconductor (CMOS) image sensors (also referred to as CIS) with smaller dimensions. In a CIS, the arrangement and dimensions of elements of an optical device affect the focal length of light. The focal length of light further affects the thickness of the elements.

Summary of the Invention

[0003] One aspect of the present disclosure provides an image sensor. The image sensor includes a photoelectric conversion layer, a color filter layer disposed on the photoelectric conversion layer, a buffer layer disposed on the color filter layer, a meta layer, and an anti-reflection layer coated on the meta layer. The meta layer includes a lining layer in the buffer layer and a plurality of upper nanostructures protruding from the lining layer in a direction away from the photoelectric conversion layer. The anti-reflection layer includes a first portion on an upper surface of a first nanostructure of the upper nanostructures and a second portion on a sidewall of the first nanostructure, and a height of the first portion is greater than a width of the second portion.

[0004] In some embodiments, the height is measured at a center of the upper surface of the first nanostructure in a direction away from the photoelectric conversion layer, and the width is measured at a middle of the sidewall of the first nanostructure in a direction perpendicular to the direction away from the photoelectric conversion layer.

[0005] In some embodiments, the anti-reflection layer includes a third portion on an upper surface of the lining layer, and a height of the third portion is greater than the width of the second portion.

[0006] In some embodiments, the ratio of the height of the first portion to the width of the second portion is 1.2 or more, and the ratio of the height of the third portion to the width of the second portion is 1.3 or more.

[0007] In some embodiments, the ratio of the height of the first portion to the width of the second portion is 1.5 or more, and the ratio of the height of the third portion to the width of the second portion is 1.7 or more.

[0008] In some embodiments, the first portion has rounded corners, and the radius of curvature of the rounded corners is smaller than the height of the first portion.

[0009] In some embodiments, the first portion has a round head that protrudes laterally from the second portion.

[0010] In some embodiments, the antireflection layer is partially connected to the adjacent upper nanostructures, and the hollow portion surrounded by the antireflection layer is between the adjacent upper nanostructures.

[0011] In some embodiments, the image sensor further includes a protective layer on the antireflection layer, the refractive index of the antireflection layer is greater than the refractive index of the protective layer, and the refractive index of the protective layer is greater than 1.

[0012] In some embodiments, the image sensor further includes an upper refractive index matching layer between the antireflection layer and the upper surface of the first nanostructure, wherein the refractive index of the meta layer is greater than the refractive index of the upper refractive index matching layer, and the refractive index of the upper refractive index matching layer is equal to or greater than the refractive index of the antireflection layer.

[0013] In some embodiments, the image sensor further includes a lower refractive index matching layer between the buffer layer and the bottom surface of the lining layer, wherein the refractive index of the meta layer is greater than the refractive index of the lower refractive index matching layer, and the refractive index of the lower refractive index matching layer is equal to or greater than the refractive index of the buffer layer.

[0014] In some embodiments, the thickness of the lower refractive index matching layer is equal to or less than the thickness of the upper refractive index matching layer.

[0015] In some embodiments, the image sensor further includes an upper refractive index matching layer between the anti-reflection layer and the top surface of the first nanostructure, and the anti-reflection layer is in direct contact with the top surface of the second nanostructure of the upper nanostructure.

[0016] In some embodiments, the first nanostructure and the second nanostructure are located in a color filter region of the color filter layer.

[0017] In some embodiments, the first nanostructure and the second nanostructure are respectively located in different color filter regions of the color filter layer.

[0018] In some embodiments, the anti-reflection layer includes a fourth portion on the top surface of the second nanostructure, and the sum of the thickness of the upper refractive index matching and the height of the first portion is greater than the height of the fourth portion.

[0019] In some embodiments, the anti-reflection layer includes a fourth portion on the top surface of the second nanostructure of the upper nanostructure and a fifth portion on the sidewall of the second nanostructure, the height of the fourth portion is greater than the width of the fifth portion, and a first ratio of the height of the first portion to the width of the second portion is greater than a second ratio of the height of the fourth portion to the width of the fifth portion.

[0020] In some embodiments, the refractive index of the meta layer is greater than the refractive index of the antireflection layer, and the refractive index of the antireflection layer is greater than 1.

[0021] In some embodiments, the meta layer includes a plurality of lower nanostructures protruding from the lining layer in a direction toward the photoelectric conversion layer, and the lower nanostructures are not aligned with the upper nanostructures.

[0022] In some embodiments, the image sensor further includes an interlayer meta layer disposed within the buffer layer, an interlayer upper refractive index matching layer between the buffer layer and the upper surface of the upper nanostructures of the interlayer meta layer, and an interlayer lower refractive index matching layer between the buffer layer and the bottom surface of the lining layer of the interlayer meta layer.

[0023] An image sensor according to an embodiment of the present disclosure includes a meta layer having nanostructures in a photoelectric conversion layer and an antireflection layer coated on the nanostructures to reduce reflection of the nanostructures. The antireflection layer is coated non-conformally on the nanostructures of the meta layer to further reduce reflection and enhance an optical effect.

[0024] It should be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further description of the claimed present disclosure.

Brief Description of the Drawings

[0025] The accompanying drawings are provided to facilitate a further understanding of the present disclosure and are incorporated herein to form a part hereof. The drawings illustrate embodiments of the present disclosure and serve to explain the principles of the present disclosure together with the description.

[0026]

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DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present disclosure will be referred to in detail, and examples thereof are shown in the accompanying drawings. As much as possible, the same reference numbers are used in the drawings and the description to refer to the same or similar components.

[0028] Furthermore, spatially relative terms such as "lower", "below", "bottom", "upper", "above", etc. may be used herein to facilitate descriptions of the relationship between one element or feature and another element or feature, as shown in the figures. Spatially relative terms are intended to encompass different directions of the device in use or operation in addition to the direction depicted in the figures. The device may be oriented in other directions (rotated 90° or in other directions), and the spatially relative descriptors used herein may be interpreted accordingly.

[0029] The disclosed image sensor can shorten the focal length of light by adjusting the phase difference. In some embodiments of the image sensor of the present disclosure, the phase difference is adjusted by a meta-layer having a nanostructure with a high refractive index. The nanostructure of the image sensor of the present disclosure is further coated with an antireflection layer to reduce the reflection of the nanostructure. More specifically, the antireflection layer is coated non-conformally on the nanostructure of the meta-layer of the image sensor of the present disclosure to further reduce reflection and enhance the optical effect.

[0030] FIG. 1 is a schematic top view of an image sensor according to some embodiments of the present disclosure, and FIG. 2 is a cross-sectional view of an image sensor according to some embodiments of the present disclosure. As shown in FIGS. 1 and 2, the image sensor 100 includes a photoelectric conversion layer 110, a color filter layer 120 disposed on the photoelectric conversion layer 110, a buffer layer 130 disposed on the color filter layer 120, a meta-layer 140 disposed on the buffer layer 130, and an antireflection layer 150 coated on the meta-layer 140.

[0031] The photoelectric conversion layer 110 includes a plurality of photodiodes 112 and one deep trench isolation structure 114. The deep trench isolation structure 114 partitions the photodiodes 112. The color filter layer 120 has a plurality of color filter regions 122 surrounded by a lattice structure 124. Each of the color filter regions 122 is disposed corresponding to a photodiode 112. The buffer layer 130 is disposed between the color filter layer 120 and the meta layer 140.

[0032] The meta layer 140 includes a lining layer 142 in the buffer layer 130 and a plurality of upper nanostructures 144. The upper nanostructures 144 protrude from the lining layer 142 in a direction D1 away from the photoelectric conversion layer 110. The lining layer 142 and the upper nanostructures 144 are integrally formed of the same material. The lining layer 142 is continuously coated on the buffer layer 130 and has a uniform thickness.

[0033] In some embodiments, the dimensions of the upper nanostructures 144, the pitch between the upper nanostructures 144, and / or the density of the upper nanostructures 144 in the same color filter region 122 may be varied according to optical design requirements. The antireflection layer 150 is coated non-conformally on the upper nanostructures 144 of the meta layer 140. In some embodiments, the refractive index of the meta layer 140 is greater than the refractive index of the antireflection layer 150, and the refractive index of the antireflection layer 150 is greater than 1. In some embodiments, the material of the antireflection layer 150 includes an inorganic oxide, a resin, a polyimide, an acrylate, a polyvinyl alcohol, or a photoresist.

[0034] FIG. 3 is a partial view of region A of the image sensor 100 of FIG. 2, and region A shows the first nanostructure of the upper nanostructure of the image sensor according to some embodiments of the present disclosure. As shown in FIG. 3, for example, the antireflection layer 150 includes a first portion 151 on the upper surface 146t of the first nanostructure 146 and a second portion 152 on the sidewall 146s of the first nanostructure 146, and the height H1 of the first portion 151 is greater than the width W1 of the second portion 152. The height H1 is measured at the center of the upper surface 146t of the first nanostructure 146 in the direction D1 away from the photoelectric conversion layer 110 (shown in FIG. 2), and the width W1 is measured at the middle of the sidewall 146s of the first nanostructure 146 in the direction D2 perpendicular to the direction D1 away from the photoelectric conversion layer 110. In some embodiments, the ratio of the height H1 of the first portion 151 to the width W1 of the second portion 152 is greater than 1.2. In some embodiments, in order to improve performance, the ratio of the height H1 of the first portion 151 to the width W1 of the second portion 152 is greater than 1.5.

[0035] The antireflection layer 150 further includes a third portion 153 on the upper surface 142t of the lining layer 142, and the height H2 of the third portion 153 is also greater than the width W1 of the second portion 152. In some embodiments, the ratio of the height H2 of the third portion 153 to the width W1 of the second portion 152 is greater than 1.3. In some embodiments, in order to improve performance, the ratio of the height H2 of the third portion 153 to the width W1 of the second portion 152 is greater than 1.7. The height H1 of the first portion 151 may be equal to, greater than, or less than the height H2 of the third portion 153.

[0036] FIGS. 4A to 4C are schematic views of steps of forming an antireflection layer on the meta layer 140 according to some embodiments of the present disclosure. As shown in FIG. 4A, the meta layer 140 is formed on the buffer layer 130, and the meta layer 140 includes a lining layer 142 in the buffer layer 130 and an upper nanostructure 144 in the lining layer 142.

[0037] 4B, a low-index material 150' is deposited on the metalayer 140. The refractive index of the low-index material 150' is less than that of the metalayer 140, and the refractive index of the low-index material 150' is greater than 1. In some embodiments, the low-index material 150' fills the spaces between the upper nanostructures 144 and provides a flat upper surface. The material of the low-index material 150' can be, for example, an inorganic oxide, a resin, a polyimide, an acrylate, polyvinyl alcohol, or a photoresist.

[0038] Then, hard mask patterns 160 are formed on the low refractive index material 150′. The hard mask patterns 160 are formed on the corresponding upper nanostructures 144. The protrusions of the hard mask patterns 160 on the buffer layer 130 respectively cover the protrusions of the upper nanostructures 144 on the buffer layer 130. More specifically, the protrusions of the hard mask patterns 160 are larger than the protrusions of the corresponding upper nanostructures 144.

[0039] After forming the hard mask pattern 160 on the upper nanostructure 144, the low refractive index material 150′ is etched using the hard mask pattern 160 as a mask. Portions of the low refractive index material 150′ covered by the hard mask pattern 160 are protected during the etching process, and portions of the low refractive index material 150′ not covered by the hard mask pattern 160 are removed during the etching process. In some embodiments, the hard mask pattern 160 is removed after the etching process. In other embodiments, the hard mask pattern 160 is consumed during the etching process.

[0040] 4C, the remaining low refractive index material becomes an antireflective layer 150 that coats the metalayer 140. The antireflective layer 150 coats the lining layer 142 and the upper nanostructures 144 of the metalayer 140. The portions of the antireflective layer 150 that are on the top surface of the lining layer 142 and the top surface of the upper nanostructures 144 are thicker than the portions of the antireflective layer 150 that are on the sidewalls of the upper nanostructures 144.

[0041] Figs. 5 to 8 are partial cross-sectional views of different embodiments of the image sensor of the present disclosure. In some embodiments, the shape of the anti-reflection layer 150 in the upper nanostructure 144 can be changed according to a selected etching process. For example, as shown in Fig. 5, the anti-reflection layer 150 includes a first portion 151 on the upper surface 144t of the upper nanostructure 144 and a second portion 152 on the sidewall 144s of the upper nanostructure 144, and the height H1 of the first portion 151 is greater than the width W1 of the second portion 152. The first portion 151 has a rounded corner 151c, and the radius of curvature R of the rounded corner 151c is smaller than the height H1 of the first portion 151. The upper surface of the first portion 151 is dome-shaped.

[0042] Alternatively, as shown in Fig. 6, the anti-reflection layer 150 includes a first portion 151 on the upper surface 144t of the upper nanostructure 144 and a second portion 152 on the sidewall 144s of the upper nanostructure 144, and the height H1 of the first portion 151 is greater than the width W1 of the second portion 152. The first portion 151 has a round head 151h protruding laterally from the second portion 152. That is, the width W2 of the first portion 151 measured from the sidewall 144s of the upper nanostructure 144 is greater than the width W1 of the second portion 152 measured from the sidewall 144s of the upper nanostructure 144. The upper surface of the first portion 151 is dome-shaped.

[0043] Alternatively, as shown in Fig. 7, in some embodiments, the aspect ratios of the anti-reflection layers 150 in different upper nanostructures 144 may be the same or different. For example, the upper nanostructure 144 includes a first nanostructure 146 and a second nanostructure 148. The dimensions of the first nanostructure 146 and the second nanostructure 148 may be the same or different. The first nanostructure 146 and the second nanostructure 148 may be in the same color filter region or in different color filter regions. The first nanostructure 146 and the second nanostructure 148 may be adjacent to each other or may be arranged with other upper nanostructures 144 therebetween.

[0044] The antireflection layer 150 includes a first portion 151 on the upper surface 146t of the first nanostructure 146 and a second portion 152 on the sidewall 146s of the first nanostructure 146, and the height H1 of the first portion 151 is greater than the width W1 of the second portion 152. The antireflection layer 150 further includes a fourth portion 154 on the upper surface 148t of the second nanostructure 148 and a fifth portion 155 on the sidewall 148s of the second nanostructure 148. The height H3 of the fourth portion 154 is greater than the width W3 of the fifth portion 155.

[0045] In some embodiments, a first ratio of the height H1 of the first portion to the width W1 of the second portion 152 is equal to a second ratio of the height H3 of the fourth portion 154 to the width W3 of the fifth portion 155.

[0046] In other embodiments, a first ratio of the height H1 of the first portion to the width W1 of the second portion 152 is greater than a second ratio of the height H3 of the fourth portion 154 to the width W3 of the fifth portion 155. In some embodiments, the aspect ratio (height / width) of the antireflection layer 150 in different upper nanostructures 144 may be 2 or more.

[0047] Alternatively, as shown in FIG. 8, the antireflection layer 150 includes a first portion 151 on the upper surface 144t of each upper nanostructure 144 and a second portion 152 on the sidewall 144s of each upper nanostructure 144. The height H1 of each first portion 151 is greater than the width W1 of each second portion 152. The antireflection layer 150 is partially connected to adjacent upper nanostructures 144, and a hollow portion AG surrounded by the antireflection layer 150 is defined between adjacent upper nanostructures 144. More specifically, the first portion 151 of the antireflection layer 150 is connected above the hollow portion AG, and the second portion 152 of the antireflection layer 150 is disposed across the hollow portion AG.

[0048] 9-11 are partial cross-sectional views of image sensors according to different embodiments of the present disclosure. In some embodiments, as shown in FIG. 9, image sensor 100 further includes a protective layer 170 on anti-reflection layer 150. The refractive index of anti-reflection layer 150 is greater than the refractive index of protective layer 170, which is greater than 1. In some embodiments, protective layer 170 provides a flat upper surface for subsequent manufacturing steps.

[0049] 10 , the image sensor 100 further includes an upper index-matching layer 180 between the antireflection layer 150 and the upper surface 144t of the upper nanostructures 144. The refractive index of the metalayer 140 is greater than the refractive index of the upper index-matching layer 180, and the refractive index of the upper index-matching layer 180 is equal to or greater than the refractive index of the antireflection layer 150. In some embodiments, the upper index-matching layer 180 is disposed between the antireflection layer 150 and the upper surface 144t of the upper nanostructures 144, and the sidewalls 144s of the upper nanostructures 144 are in direct contact with the antireflection layer 150. The sum of the height H1 of the first portion 151 of the antireflection layer 150 and the thickness T1 of the upper index-matching layer 180 is greater than the height H2 of the third portion 153 of the antireflection layer 150.

[0050] 11, the shape of the first portion 151 of the antireflective layer 150 may be modified to have rounded corners or rounded tops. In some embodiments, the metalayer 140 further includes lower nanostructures 145 that protrude from the lining layer 142 in a direction opposite to the upper nanostructures 144. The lower nanostructures 145 may or may not be aligned with the upper nanostructures 144.

[0051] Preferably, the image sensor 100 further includes a lower index matching layer 190 between the buffer layer 130 and the bottom surface 142b of the lining layer 142 of the meta layer 140. The refractive index of the meta layer 140 is greater than the refractive index of the lower index matching layer 190, which is equal to or greater than the refractive index of the buffer layer 130. In some embodiments, the thickness T2 of the lower index matching layer 190 is less than or equal to the thickness T1 of the upper index matching layer 180. In some embodiments, the bottom surface 145b of the lower nanostructure 145 is in direct contact with the buffer layer 130.

[0052] 12 to 15 are cross-sectional views of image sensors according to different embodiments of the present disclosure. As shown in Fig. 12, the image sensor 100 includes a photoelectric conversion layer 110, a color filter layer 120 disposed on the photoelectric conversion layer 110, a buffer layer 130 disposed on the color filter layer 120, a meta layer 140 disposed on the buffer layer 130, and an anti-reflection layer 150 non-conformally coated on the meta layer 140.

[0053] The metalayer 140 includes a lining layer 142 on the buffer layer 130 and upper nanostructures 144. The upper nanostructures 144 protrude from the lining layer 142 in a direction D1 away from the photoelectric conversion layer 110. The metalayer 140 further includes lower nanostructures 145 protruding from the lining layer 142 in a direction D3 toward the photoelectric conversion layer 110. The lower nanostructures 145 may or may not be aligned with the upper nanostructures 144.

[0054] In some embodiments, the dimensions of the upper nanostructures 144 and the lower nanostructures 145, the pitch between the upper nanostructures 144 and the lower nanostructures 145, and / or the density of the upper nanostructures 144 and the lower nanostructures 145 in the same color filter region 122 may be varied according to optical design requirements. The anti-reflective layer 150 is non-conformally coated on the upper nanostructures 144 of the metalayer 140. In some embodiments, the aspect ratio (height / width) of the anti-reflective layer 150 on different upper nanostructures 144 may be varied according to optical design requirements.

[0055] The image sensor 100 further includes an upper refractive index matching layer 180 between the antireflection layer 150 and the upper surface 144t of the upper nanostructure 144, and a lower refractive index matching layer 190 between the buffer layer 130 and the bottom surface 142b of the lining layer 142 of the meta layer 140. In some embodiments, the refractive index of the meta layer 140 is greater than the refractive index of the upper refractive index matching layer 180, the refractive index of the upper refractive index matching layer 180 is equal to or greater than the refractive index of the antireflection layer 150, and the refractive index of the antireflection layer 150 is greater than 1. The refractive index of the meta layer 140 is greater than the refractive index of the lower refractive index matching layer 190, and the refractive index of the lower refractive index matching layer 190 is equal to or greater than the refractive index of the buffer layer 130.

[0056] As shown in FIG. 13, the image sensor 100 has two meta layers. The image sensor 100 further includes an interlayer meta layer 200 disposed within the buffer layer 130. The interlayer meta layer 200 is disposed below the meta layer 140. In some embodiments, the interlayer meta layer 200 includes a lining layer 202, a plurality of upper nanostructures 204 protruding from the lining layer 202 in a direction D1 away from the photoelectric conversion layer 110, and a plurality of lower nanostructures 206 protruding from the lining layer 202 in a direction D3 toward the photoelectric conversion layer 110. The arrangement of the upper nanostructures 204 and the lower nanostructures 206 of the interlayer meta layer 200 may be the same as the arrangement of the upper nanostructures 144 and the lower nanostructures 145 of the interlayer meta layer 140.

[0057] The image sensor 100 further includes an interlayer upper refractive index matching layer 210 between the buffer layer 130 and the upper surface 204t of the upper nanostructures 204 of the interlayer meta layer 200. The image sensor 100 further includes an interlayer lower refractive index matching layer 220 between the buffer layer 130 and the bottom surface 202b of the lining layer 202 of the interlayer meta layer 200.

[0058] 14, the designs of the anti-reflection layer 150 and the upper index matching layer 180 in the same color filter region can be varied. For example, the metalayer 140 includes a first nanostructure 146 and a second nanostructure 148 in the same color filter region 122a. The upper index matching layer 180 is disposed between the anti-reflection layer 150 and the upper surface 146t of the first nanostructure 146, and the anti-reflection layer 150 is in direct contact with the upper surface 148t of the second nanostructure 148.

[0059] In some embodiments, the anti-reflection layer 150 includes a fourth portion 154 on the upper surface 148t of the second nanostructure 148, and the sum of the upper refractive index matching thickness T1 and the height H1 of the first portion 151 is greater than the height H3 of the fourth portion 154.

[0060] 15, the designs of the anti-reflection layer 150 and the upper index matching layer 180 in different color filter regions can be varied. For example, the meta layer 140 includes a first nanostructure 146 in the first color filter region 122a and a second nanostructure 148 in the second color filter region 122b. The wavelength band of the first color filter region 122a is different from the wavelength band of the second color filter region 122b.

[0061] The upper index-matching layer 180 is disposed between the anti-reflective layer 150 and the top surfaces 146 t of the first nanostructures 146 , and the anti-reflective layer 150 is in direct contact with the top surfaces 148 t of the second nanostructures 148 .

[0062] In some embodiments, the anti-reflection layer 150 includes a fourth portion 154 on the upper surface 148t of the second nanostructure 148, and the sum of the upper refractive index matching thickness T1 and the height H1 of the first portion 151 is greater than the height H3 of the fourth portion 154.

[0063] An image sensor according to an embodiment of the present disclosure includes a metalayer having nanostructures in a photoelectric conversion layer, and an anti-reflection layer coated on the nanostructures to reduce reflection of the nanostructures, the anti-reflection layer being non-conformally coated on the nanostructures of the metalayer to further reduce reflection and enhance optical efficiency.

[0064] It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the present disclosure. In view of the foregoing, the present disclosure is intended to cover modifications and variations of the present invention that fall within the scope of the following claims and their equivalents.

Claims

1. A photoelectric conversion layer, a color filter layer disposed on the photoelectric conversion layer, a buffer layer disposed on the color filter layer, a meta layer including a lining layer in the buffer layer and a plurality of upper nanostructures protruding from the lining layer in a direction away from the photoelectric conversion layer, wherein the lining layer and the upper nanostructures are integrally formed of the same material, and the lining layer is continuously coated on the buffer layer and has a uniform thickness, the meta layer; an antireflection layer coated on the meta layer, including a first portion on an upper surface of a first nanostructure of the upper nanostructures and a second portion on a sidewall of the first nanostructure, wherein a height of the first portion is greater than a width of the second portion, the antireflection layer; An image sensor comprising the above.

2. The height is measured at a central portion of the upper surface of the first nanostructure in a direction away from the photoelectric conversion layer, the width is measured at an intermediate portion of the sidewall of the first nanostructure in a direction perpendicular to the direction away from the photoelectric conversion layer, a refractive index of the meta layer is greater than a refractive index of the antireflection layer, and the refractive index of the antireflection layer is greater than 1. The image sensor according to Claim 1.

3. The antireflection layer includes a third portion on an upper surface of the lining layer, a height of the third portion is greater than the width of the second portion, a ratio of the height of the first portion to the width of the second portion is 1.2 or more, and a ratio of the height of the third portion to the width of the second portion is 1.3 or more. The image sensor according to Claim 1.

4. The antireflection layer includes a third portion on an upper surface of the lining layer, a height of the third portion is greater than the width of the second portion, a ratio of the height of the first portion to the width of the second portion is 1.5 or more, and a ratio of the height of the third portion to the width of the second portion is 1.7 or more. The image sensor according to Claim 1.

5. The first portion has a rounded corner, and a radius of curvature of the rounded corner is smaller than the height of the first portion. The image sensor according to Claim 1.

6. The first portion has a rounded head protruding laterally from the second portion. The image sensor according to Claim 1.

7. The antireflection layer is partially connected to adjacent upper nanostructures, and a hollow portion surrounded by the antireflection layer is between adjacent upper nanostructures. The image sensor according to Claim 1.

8. The image sensor according to claim 1, further comprising a protective layer in the antireflection layer, wherein the refractive index of the antireflection layer is greater than the refractive index of the protective layer, and the refractive index of the protective layer is greater than 1.

9. An upper refractive index matching layer between the antireflection layer and the upper surface of the first nanostructure, wherein the refractive index of the meta layer is greater than the refractive index of the upper refractive index matching layer, and the refractive index of the upper refractive index matching layer is greater than or equal to the refractive index of the antireflection layer, and an upper refractive index matching layer; A lower refractive index matching layer between the buffer layer and the bottom surface of the lining layer, wherein the refractive index of the meta layer is greater than the refractive index of the lower refractive index matching layer, the refractive index of the lower refractive index matching layer is greater than or equal to the refractive index of the buffer layer, and the thickness of the lower refractive index matching layer is less than or equal to the thickness of the upper refractive index matching layer, and a lower refractive index matching layer; The image sensor according to claim 1, further comprising.

10. The image sensor according to claim 1, further comprising an upper refractive index matching layer between the antireflection layer and the upper surface of the first nanostructure, wherein the antireflection layer is in direct contact with the upper surface of the second nanostructure of the upper nanostructure.

11. The image sensor according to claim 10, wherein the first nanostructure and the second nanostructure are located in a color filter region of the color filter layer, and the first nanostructure and the second nanostructure are located in different color filter regions of the color filter layer, respectively.

12. The image sensor according to claim 10, wherein the antireflection layer includes a fourth portion on the upper surface of the second nanostructure, and the sum of the thickness of the upper refractive index matching layer and the height of the first portion is greater than the height of the fourth portion.

13. The image sensor according to claim 1, wherein the antireflection layer includes a fourth portion on the upper surface of the second nanostructure of the upper nanostructure and a fifth portion on the side wall of the second nanostructure, the height of the fourth portion is greater than the width of the fifth portion, and a first ratio of the height of the first portion to the width of the second portion is greater than a second ratio of the height of the fourth portion to the width of the fifth portion.

14. The image sensor according to claim 1, wherein the meta layer includes a plurality of lower nanostructures protruding from the lining layer in a direction toward the photoelectric conversion layer, and the lower nanostructures are not aligned with the upper nanostructures.

15. An interlayer meta layer disposed in the buffer layer; An upper interlayer refractive index matching layer between the buffer layer and the upper surface of the upper nanostructure of the interlayer metal layer, and A lower interlayer refractive index matching layer between the buffer layer and the bottom surface of the lining layer of the interlayer metal layer, and The image sensor according to claim 1, further comprising.

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