Image sensor

Abstract

SOLUTION: An 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 anti-reflective 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 nano-structures 144 protruding from the lining layer in a direction away from the photoelectric conversion layer. The anti-reflection layer includes a first part 151 on an upper surface of a first nano-structure 146 of the upper nano-structures and a second part 152 on a sidewall of the first nano-structure, and a height H1 of the first part is greater than a width W1 of the second part.EFFECT: An anti-reflection layer is non-conformally coated on nano-structures of a meta layer to further reduce reflections and enhance optical effects.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to image sensors, and more particularly, to image sensors having anti-reflection structures. [Background technology]

[0002] With the development of semiconductor devices, there is an increasing demand for smaller dimensioned complementary metal oxide semiconductor (CMOS) image sensor (also known as CIS) technology. In CIS, the layout and dimensions of the optical device elements affect the focal length of the light, which in turn 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 metalayer, and an anti-reflection layer coated on the metalayer. The metalayer includes a lining layer on 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 a top surface of a first nanostructure of the upper nanostructures and a second portion on a sidewall of the first nanostructure, wherein the height of the first portion is greater than the width of the second portion.

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

[0005] In some embodiments, the antireflective layer includes a third portion on an upper surface of the lining layer, the height of the third portion being greater than the width of the second portion.

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

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

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

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

[0010] In some embodiments, the antireflective layer is partially connected to adjacent upper nanostructures, and a cavity surrounded by the antireflective layer is between adjacent upper nanostructures.

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

[0012] In some embodiments, the image sensor further includes an upper refractive index matching layer between the anti-reflection 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 anti-reflection layer.

[0013] In some embodiments, the image sensor further includes a lower refractive index matching layer between the buffer layer and a 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 index-matching layer is less than or equal to the thickness of the upper 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 upper surface of the first nanostructure, and the anti-reflection layer is in direct contact with the upper surface of the second nanostructure of the upper nanostructure.

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

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

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

[0019] In some embodiments, the antireflective layer includes a fourth portion on the top surface of a second nanostructure of the upper nanostructure and a fifth portion on a sidewall of the second nanostructure, wherein 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 metalayer is greater than the refractive index of the antireflective layer, which is greater than one.

[0021] In some embodiments, the metalayer includes a plurality of lower nanostructures that protrude from the lining layer in a direction toward the photovoltaic layer, the lower nanostructures not aligned with the upper nanostructures.

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

[0023] In an embodiment of the present disclosure, an image sensor 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.

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

[0025] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the disclosure.

[0026] [Figure 1] FIG. 1 is a schematic top view of an image sensor according to some embodiments of the present disclosure. [Figure 2] 1 is a cross-sectional view of an image sensor according to some embodiments of the present disclosure. [Figure 3] 3 is a partial view of area A of the image sensor of FIG. 2. [Figure 4A] 1A-1C are schematic diagrams of different steps for forming an anti-reflective layer on a metalayer according to some embodiments of the present disclosure. [Figure 4B] 1A-1C are schematic diagrams of different steps for forming an anti-reflective layer on a metalayer according to some embodiments of the present disclosure. [Figure 4C] 1A-1C are schematic diagrams of different steps for forming an anti-reflective layer on a metalayer according to some embodiments of the present disclosure. [Figure 5] 1 is a partial cross-sectional view of an image sensor according to another embodiment of the present disclosure. [Figure 6] 1 is a partial cross-sectional view of an image sensor according to another embodiment of the present disclosure. [Figure 7] 1 is a partial cross-sectional view of an image sensor according to another embodiment of the present disclosure. [Figure 8] 1 is a partial cross-sectional view of an image sensor according to another embodiment of the present disclosure. [Figure 9] 1 is a partial cross-sectional view of an image sensor according to another embodiment of the present disclosure. [Figure 10] 1 is a partial cross-sectional view of an image sensor according to another embodiment of the present disclosure. [Figure 11] 1 is a partial cross-sectional view of an image sensor according to another embodiment of the present disclosure. [Figure 12] 1 is a cross-sectional view of an image sensor according to another embodiment of the present disclosure. [Figure 13] 1 is a cross-sectional view of an image sensor according to another embodiment of the present disclosure. [Figure 14] 1 is a cross-sectional view of an image sensor according to another embodiment of the present disclosure. [Figure 15] 1 is a cross-sectional view of an image sensor according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0027] Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

[0028] Additionally, spatially relative terms such as "bottom," "lower," "bottom," "upper," "top," and the like may be used herein for ease of description to describe the relationship of one element or feature to another, as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) 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 metalayer having nanostructures with a high refractive index. The nanostructures of the image sensor of the present disclosure are further coated with an anti-reflection layer to reduce reflection of the nanostructures. More specifically, the anti-reflection layer is non-conformally coated on the nanostructures of the metalayer of the image sensor of the present disclosure to further reduce reflection and enhance optical efficiency.

[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 the image sensor according to some embodiments of the present disclosure. As shown in Fig. 1 and Fig. 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 anti-reflection layer 150 coated on the meta layer 140.

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

[0032] The metalayer 140 includes a lining layer 142 on 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 depending on optical design requirements. The anti-reflection layer 150 is non-conformally coated on the upper nanostructures 144 of the metalayer 140. In some embodiments, the refractive index of the metalayer 140 is greater than the refractive index of the anti-reflection layer 150, which is greater than 1. In some embodiments, the material of the anti-reflection layer 150 includes an inorganic oxide, a resin, a polyimide, an acrylate, polyvinyl alcohol, or a photoresist.

[0034] 3 is a partial view of region A of the image sensor 100 of FIG. 2, where region A shows a 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 a top surface 146t of the first nanostructure 146 and a second portion 152 on a sidewall 146s of the first nanostructure 146, where 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 a center of the top surface 146t of the first nanostructure 146 in a direction D1 away from the photoelectric conversion layer 110 (shown in FIG. 2), and the width W1 is measured at a center of the sidewall 146s of the first nanostructure 146 in a 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, 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 anti-reflective 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, 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] 4A-4C are schematic diagrams illustrating steps for forming an anti-reflective layer on a metalayer 140 according to some embodiments of the present disclosure. As shown in FIG. 4A, the metalayer 140 is formed on a buffer layer 130, and the metalayer 140 includes a lining layer 142 on the buffer layer 130 and an upper nanostructure 144 on 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] 5-8 are partial cross-sectional views of different embodiments of the image sensor of the present disclosure. In some embodiments, the shape of the anti-reflective layer 150 on the upper nanostructure 144 can be varied depending on the selected etching process. For example, as shown in FIG. 5, the anti-reflective 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, where the height H1 of the first portion 151 is greater than the width W1 of the second portion 152. The first portion 151 has rounded corners 151c, and the radius of curvature R of the rounded corners 151c is smaller than the height H1 of the first portion 151. The top surface of the first portion 151 is dome-shaped.

[0042] 6, the anti-reflection layer 150 includes a first portion 151 on the top surface 144t of the upper nanostructure 144 and a second portion 152 on the sidewall 144s of the upper nanostructure 144, where 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 head 151h that protrudes 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 top surface of the first portion 151 is dome-shaped.

[0043] Alternatively, as shown in FIG. 7 , in some embodiments, the aspect ratios of the antireflective layer 150 on different upper nanostructures 144 may be the same or different. For example, the upper nanostructures 144 include 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 separated by other upper nanostructures 144.

[0044] The antireflective layer 150 includes a first portion 151 on the top surface 146t of the first nanostructure 146 and a second portion 152 on the sidewall 146s of the first nanostructure 146, where the height H1 of the first portion 151 is greater than the width W1 of the second portion 152. The antireflective layer 150 further includes a fourth portion 154 on the top 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 ratios (height / width) of the antireflective layer 150 on different upper nanostructures 144 may be 2 or greater.

[0047] 8 , each antireflection layer 150 includes a first portion 151 located on the top surface 144t of the upper nanostructure 144 and a second portion 152 located on the sidewall 144s of the 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 the 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 index-matching layer 180 between the anti-reflection layer 150 and the top surface 144t of the upper nanostructure 144, and 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. In some embodiments, the refractive index of the meta layer 140 is greater than the refractive index of the upper index-matching layer 180, which is greater than or equal to the refractive index of the anti-reflection layer 150, which is greater than 1. The refractive index of the meta layer 140 is greater than the refractive index of the lower index-matching layer 190, which is greater than or equal to the refractive index of the buffer layer 130.

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

[0057] The image sensor 100 further includes an interlayer upper index matching layer 210 between the buffer layer 130 and the top surface 204t of the upper nanostructure 204 of the interlayer metalayer 200. The image sensor 100 further includes an interlayer lower index matching layer 220 between the buffer layer 130 and the bottom surface 202b of the lining layer 202 of the interlayer metalayer 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 disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this invention provided they come 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 lining layer on the buffer layer and a metalayer including a plurality of upper nanostructures protruding from the lining layer in a direction away from the photovoltaic layer; an anti-reflective layer coated on the metalayer, the anti-reflective layer including a first portion on a top surface of a first nanostructure of the upper nanostructure and a second portion on a sidewall of the first nanostructure, the height of the first portion being greater than the width of the second portion; an image sensor including:

2. 2. The image sensor of claim 1, wherein the height is measured at the center of the top surface of the first nanostructure in a direction away from the photoelectric conversion layer, the width is measured at the middle of the sidewall of the first nanostructure in a direction perpendicular to the direction away from the photoelectric conversion layer, and the refractive index of the metalayer is greater than the refractive index of the antireflection layer, and the refractive index of the antireflection layer is greater than 1.

3. 2. The image sensor of claim 1, wherein the anti-reflective layer includes a third portion on an upper surface of the lining layer, the height of the third portion being greater than the width of the second portion, a ratio of the height of the first portion to the width of the second portion being 1.2 or greater, and a ratio of the height of the third portion to the width of the second portion being 1.3 or greater.

4. 2. The image sensor of claim 1, wherein the anti-reflective layer includes a third portion on an upper surface of the lining layer, the height of the third portion being greater than the width of the second portion, a ratio of the height of the first portion to the width of the second portion being 1.5 or greater, and a ratio of the height of the third portion to the width of the second portion being 1.7 or greater.

5. The image sensor of claim 1 , wherein the first portion has rounded corners, the radius of curvature of the rounded corners being less than the height of the first portion.

6. The image sensor of claim 1 , wherein the first portion has a rounded head projecting laterally from the second portion.

7. The image sensor of claim 1 , wherein the anti-reflection layer is partially connected to adjacent upper nanostructures, and a cavity surrounded by the anti-reflection layer is between adjacent upper nanostructures.

8. The image sensor of claim 1 , further comprising a protective layer on the anti-reflection layer, the refractive index of the anti-reflection layer being greater than the refractive index of the protective layer, the refractive index of the protective layer being greater than 1.

9. an upper index-matching layer between the anti-reflection layer and a top surface of the first nanostructure, wherein the refractive index of the meta-layer is greater than the refractive index of the upper index-matching layer, and the refractive index of the upper index-matching layer is equal to or greater than the refractive index of the anti-reflection layer; a lower index matching layer between the buffer layer and the bottom surface of the lining layer, the refractive index of the metalayer being greater than the refractive index of the lower index matching layer, the refractive index of the lower index matching layer being equal to or greater than the refractive index of the buffer layer, and the thickness of the lower index matching layer being equal to or less than the thickness of the upper index matching layer; The image sensor of claim 1 further comprising:

10. 10. The image sensor of claim 1, further comprising an upper refractive index matching layer between the anti-reflection layer and the top surface of the first nanostructure, the anti-reflection layer being in direct contact with the top surface of the second nanostructure of the upper nanostructure.

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

12. 11. The image sensor of claim 10, wherein 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 index matching layer and the height of the first portion is greater than the height of the fourth portion.

13. 2. The image sensor of claim 1, wherein the anti-reflection layer includes a fourth portion on a top surface of a second nanostructure of the upper nanostructure and a fifth portion on a sidewall of the second nanostructure, wherein a height of the fourth portion is greater than a 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 of claim 1 , wherein the metalayer includes a plurality of lower nanostructures protruding from the lining layer in a direction toward the photoelectric conversion layer, the lower nanostructures not aligned with the upper nanostructures.

15. an interlayer metalayer disposed within the buffer layer; an interlayer upper index matching layer between the buffer layer and a top surface of the upper nanostructure of the interlayer metalayer; an interlayer lower index matching layer between the buffer layer and a bottom surface of the interlayer metalayer lining layer; The image sensor of claim 1 further comprising:

Images