Imaging device and its manufacturing method

Abstract

Imaging device and manufacturing method thereof The imaging device comprises a plurality of photodiodes, a color filter layer, and a meta-surface layer. The color filter layer is located above the plurality of photodiodes, the color filter layer comprising a blue filter, a red filter, a first green filter, and a second green filter. The meta-surface layer is located above the color filter layer and comprises a first pixel unit, the first pixel unit comprising a blue region above the blue filter, a red region above the red filter, a first green region above the first green filter, and a second green region above the second green filter.The first green region has a first central nano-post offset from the center of the first green region by a first longitudinal offset in a Y-axis direction and a first horizontal offset in an X-axis direction of the first central nano-post in top view.

Description

Title of the invention: Imaging device and its manufacturing method Technical field

[0001] The present description relates to an imaging device and a method of manufacturing the imaging device. Prior art

[0002] In a complementary metal oxide semiconductor (CMOS) (also referred to as CIS) image sensor, a receiving component, such as a microlens layer or a metasurface layer, may function to receive and separate incident light comprising different wavelengths with different colors. A color filter layer may be disposed beneath the receiving component and acts as an absorber to absorb light with a particular wavelength band before the light propagates into photodiodes. The routing of the color of the light into the imaging device also affects the performance of the imaging device.

[0003] However, the pattern of the color filters in the color filter layer and the design of the meta-surface layer, e.g., the arrangement and shapes of the nanostructures in the meta-surface layer, may impact the color routing of the light. Therefore, there is a need to design the meta-surface layer to increase the performance of the imaging device. Summary of the Invention

[0004] One aspect of the present disclosure is to provide an imaging device. The imaging device includes a plurality of photodiodes, a color filter layer, and a meta-surface layer. The color filter layer is located above the plurality of photodiodes, the color filter layer including a blue filter, a red filter, a first green filter, and a second green filter. The meta-surface layer is located above the color filter layer and includes a first pixel unit, the first pixel unit including a blue region above the blue filter, a red region above the red filter, a first green region above the first green filter, and a second green region above the second green filter.The first green region has a first central nanopost offset from a center of the first green region by a first longitudinal offset in the direction of a Y axis and a first horizontal offset in the direction of an X axis of the first central nanopost in top view. The second green region has a second central nanopost offset from . at a center of the second green region of a second longitudinal offset in the Y-axis direction and a second horizontal offset in the X-axis direction of the second central nano-post in top view.

[0005] In some embodiments, the first longitudinal offset and the first horizontal offset are determined based on an angle of incidence and an azimuthal angle of the first green region. The angle of incidence of the first green region is between first light incident on a top surface of the first green region and a line normal to the top surface of the first green region. The azimuthal angle of the first green region is between a horizontal axis of the meta-surface layer that passes through a center of the meta-surface layer and a first connecting line between the center of the first green region and the center of the meta-surface layer.

[0006] In some embodiments, the meta-surface layer further comprises a second pixel unit, wherein the second pixel unit comprises a third green region, the third green region comprises a third central nano-post offset from a center of the third green region by a third longitudinal offset in the Y-axis direction and a third horizontal offset in the X-axis direction of the third central nano-post in top view, wherein the third longitudinal offset and the third horizontal offset are determined based on an incident angle and an azimuthal angle of the third green region. The incident angle of the third green region is between a second light incident on a top surface of the third green region and a line normal to the top surface of the third green region.The azimuthal angle of the third green region is between the horizontal axis of the meta-surface layer that passes through the center of the meta-surface layer and a second connecting line between the center of the third green region and the center of the meta-surface layer. The first longitudinal offset of the first central nano-post and the third longitudinal offset of the third central nano-post satisfy the following equation: . D gr (0, 0) = D GR (e ; , 0j) + A 0-^ + A 0-gf in which 0 is the incidence angle of the first green region and 0 is not equal to 0 degrees, 0 is the azimuthal angle of the first green region, DGR ( 0, 0 ) is the first longitudinal offset of the first central nano-pole, ©i is the incidence angle of the third green region and ©j is not equal to 0 degrees, 0, is the azimuthal angle of the third green region, DGR ( 0,, 0j ) is the third longitudinal offset of the third central nano-pole, A0 is a first difference between the incidence angle of the first green region and the angle of incidence of the third green region, A0 is a second difference between the azimuthal angle of the first green region and the azimuthal angle of the third green region.

[0007] In some embodiments, the first horizontal offset of the first central nanopost and the third horizontal offset of the third central nanopost satisfy the following equation: D ob(0, 0) = 0^(0, 0j) + 40¾ 5 + A 0¾ 5 where DGB(0, 0) is the first horizontal offset of the first central nano-post, and DGB(0j, 0j) is the third horizontal offset of the third central nano-post.

[0008] In some embodiments, an edge of the first green region is offset from a corresponding edge of the first green filter by a first green region offset distance, the color filter layer includes a third green filter adjacent to the first green filter, the third green region is above the third green filter, and an edge of the third green region is offset from a corresponding edge of the third green filter by a third green region offset distance. The first green region offset distance and the third green region offset distance satisfy the following equation: sM = S(e,) +A6f in which is the offset distance of the first green region, and S ( 0, ) is the offset distance of the third green region.

[0009] In some embodiments, the offset distance of the first green region is between 0 and 300 nm, 0 is greater than 0 degrees and < 35 degrees, and 0 is between 0 and 360 degrees.

[0010] In some embodiments, the meta-surface layer further comprises a plurality of peripheral nano-posts, and the peripheral nano-posts are located at the corners of the blue region, the red region, the first green region, and the second green region.

[0011] In some embodiments, the first longitudinal offset of the first central nano-post is in the range of 1 / 5 of a dimension of the first green filter, and the first horizontal offset of the first central nano-post is in the range of 1 / 5 of the dimension of the first green filter.

[0012] In some embodiments, the first longitudinal offset and the first horizontal offset comprise positive offsets. The second longitudinal offset and the second horizontal offset comprise positive offsets. The positive offset of the first longitudinal offset is defined by an offset of the first green region to the red region, and the positive shift of the first horizontal shift is defined by a shift from the first green region to the blue region. The positive shift of the second longitudinal shift is defined by a shift from the second green region to the blue region, and the positive shift of the second horizontal shift is defined by a shift from the second green region to the red region.

[0013] In some embodiments, the first longitudinal offset and the first horizontal offset comprise negative offsets. The second longitudinal offset and the second horizontal offset comprise negative offsets. The negative offset of the first longitudinal offset is defined by an offset of the first green region away from the red region, and the negative offset of the first horizontal offset is defined by an offset of the first green region away from the blue region. The negative offset of the second longitudinal offset is defined by an offset of the second green region away from the blue region, and the negative offset of the second horizontal offset is defined by an offset of the second green region away from the red region.

[0014] In some embodiments, the meta-surface layer further comprises a filler material, the filler material laterally surrounding the first central nano-post and the second central nano-post, wherein the refractive index of the filler material is between 1.0 and 1.6.

[0015] In some embodiments, the imaging device further comprises a dielectric layer, and the dielectric layer is disposed between the color filter layer and the blue filter, the red filter, the first green filter, and the second green filter.

[0016] In some embodiments, a dimension of each of the blue region, the red region, the first green region, and the second green region is between 400 nm and 700 nm. The refractive index of the first central nano-post is between 1.8 and 3.5.

[0017] One aspect of the present disclosure is to provide a method of manufacturing an imaging device. The method comprises the following steps. A plurality of photodiodes are provided. A color filter layer is formed above the plurality of photodiodes, the color filter layer comprising a blue filter, a red filter, a first green filter, and a second green filter. A meta-surface layer is formed above the color filter layer, the meta-surface layer comprising a first pixel unit, the first pixel unit comprising a blue region above the blue filter, a red region above the red filter, a first green region above the first green filter, and a second green region above the second green filter, the first green region comprising a first central nano-post, and the second green region comprising a second central nano-post.The formation of the meta-surface layer involves the following steps: the . forming the first central nano-post offset from a center of the first green region by a first longitudinal offset in the Y-axis direction and a first horizontal offset in the X-axis direction of the first central nano-post in top view; and forming the second central nano-post offset from a center of the second green region by a second longitudinal offset in the Y-axis direction and a second horizontal offset in the X-axis direction of the second central nano-post in top view.

[0018] In some embodiments, the first longitudinal offset and the first horizontal offset are determined based on an angle of incidence and an azimuthal angle of the first green region. The angle of incidence of the first green region is between first light incident on a top surface of the first green region and a line normal to the top surface of the first green region. The azimuthal angle of the first green region is between a horizontal axis of the meta-surface layer that passes through a center of the meta-surface layer and a first connecting line between the center of the first green region and the center of the meta-surface layer.

[0019] In some embodiments, forming the meta-surface layer further comprises forming a plurality of peripheral nano-posts at the corners of the blue region, the red region, the first green region, and the second green region.

[0020] In some embodiments, forming the meta-surface layer further comprises forming a filler material laterally surrounding the peripheral nanoposts, the first central nanopost, and the second central nanopost.

[0021] In some embodiments, the method of manufacturing the imaging device further comprises forming a dielectric layer disposed between the color filter layer and the blue filter, the red filter, the first green filter, and the second green filter.

[0022] In some embodiments, the first longitudinal offset and the first horizontal offset comprise positive offsets. The second longitudinal offset and the second horizontal offset comprise positive offsets. The positive offset of the first longitudinal offset is defined by an offset from the first green region to the red region, and the positive offset of the first horizontal offset is defined by an offset from the first green region to the blue region. The positive offset of the second longitudinal offset is defined by an offset from the second green region to the blue region, and the positive offset of the second horizontal offset is defined by an offset from the second green region to the red region.

[0023] In some embodiments, the first longitudinal offset and the first horizontal offset comprise negative offsets. The second longitudinal offset and the second horizontal offset comprise negative offsets. The negative offset of the first longitudinal offset is defined by an offset of the first green region away from the red region, and the negative offset of the first horizontal offset is defined by an offset of the first green region away from the blue region. The negative offset of the second longitudinal offset is defined by an offset of the second green region away from the blue region, and the negative offset of the second horizontal offset is defined by an offset of the second green region away from the red region. Brief description of the drawings

[0024] Aspects of the present description will be better understood from the following description read in conjunction with the accompanying figures. It will be noted that, in accordance with normal industry practice, the various elements are not drawn to scale. In practice, the dimensions of the various elements may be arbitrarily increased or decreased for the sake of clarity.

[0025] [Fig.l] is a perspective view of an imaging device when incident light is not occurring at normal incidence, according to certain embodiments of the present disclosure.

[0026] [Fig.2] is a side view of a portion of the imaging device of [Fig.l].

[0027] [Fig.3] is a top view of a meta-surface layer of [Fig.l].

[0028] [Fig.4A] is a top view of a structure of a meta-surface layer when incident light occurs at normal incidence according to certain embodiments of the present disclosure.

[0029] [Fig.4B] is a top view of a structure of the meta-surface layer of [Fig.1].

[0030] [Fig.5A] is a coordinate illustrating the definitions of the various parameters when incident light occurs at normal incidence.

[0031] [Fig.5B], [Fig.5C] and [Fig.5D] are coordinates illustrating the definitions of different parameters when incident light does not occur at normal incidence.

[0032] [Fig.5E] is an array of a meta-surface layer according to certain embodiments of the present disclosure.

[0033] [Fig.5F] is a schematic diagram of reference points.

[0034] Figure 6A is a side view of a portion of an imaging device at an angle of incidence (0j) of a third green region according to certain embodiments of the present disclosure.

[0035] [Fig.6B] is a side view of a portion of an imaging device at an angle of incidence (0) of a first green region according to certain embodiments of the present disclosure.

[0036] [Fig.7] is a top view of a meta-surface layer according to certain modes of carrying out this description. Description of the embodiments

[0037] The following description provides numerous embodiments, or examples, for implementing various elements of the proposed subject matter. Particular examples of components and arrangements are described below to simplify this description. Of course, these are examples only and are not intended to be limiting. For example, the formation of a first element on or above a second element in the following description may include embodiments in which the first and second elements are formed in direct contact, and may also include embodiments in which additional elements may be formed between the first and second elements, such that the first and second elements may not be in direct contact.

[0038] In addition, the present description may repeat reference numbers and / or letters in the various examples. This repetition is intended to simplify and clarify and does not in itself impose a relationship between the different embodiments and / or configurations discussed.

[0039] It should be noted that, although the terms "first", "second", etc. may be used herein to describe various elements, such elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a "first element" may be referred to as a "second element" and, similarly, a "second element" may be referred to as a "first element", without departing from the scope of the embodiments. As used herein, the term "and / or" includes all combinations of one or more of the listed elements together.

[0040] In addition, spatial terms such as "under," "below," "lower," "above," "upper," and the like may be used herein to facilitate describing the relationship of one element or feature to another element(s) or feature(s), as illustrated in the figures. The spatial terms are intended to encompass different orientations of the apparatus in use or operation, in addition to the orientation shown in the figures. The apparatus may be oriented differently (rotated 90 degrees or in other orientations), and the relative spatial descriptors used herein may also be interpreted accordingly.

[0041] In the present description, the terms "about", "approximately" and "substantially" preferably mean ± 20% of the indicated value, more preferably ± 10% of the indicated value, more preferably ± 5% of the indicated value, more preferably ± 3% of the indicated value, more preferably ± 2% of the indicated value, more preferably ± 1% of the indicated value and even more preferably ± 0.5% of the indicated value. The value indicated in the present description is an approximate value.

[0042] In response to the constant reduction in pixel size, the reception of light by each pixel (which can be defined by different color filters) and the uniformity of light reception between different pixels have become issues of critical importance. If the reception of light between different pixels is unbalanced, an imaging device will experience color variations and result in insufficient quantum efficiency (QE) between different pixels, which will decrease the performance of the imaging device. In addition, the angle of incidence of an incident light also has an impact on the quantum efficiency of the imaging device.

[0043] Hereinafter, several embodiments of the present invention are described with the aid of the accompanying figures. Numerous practical details are described in the remainder of the description for clarity. However, it should be noted that these practical details should not be used to limit the present invention. That is, in certain embodiments of the present invention, these practical details are not necessary. In addition, in order to simplify the figures, certain conventional structures and elements will be shown in the figures in a simplified schematic manner.

[0044] Since the incident light is a combination of different wavelengths with different colors and the photodiodes of the imaging device are used to detect the incident light, it is necessary to separate the incident light through a meta-surface layer and a color filter layer before transmitting the light to the photodiodes. The meta-surface consists of a plurality of nano structures (such as nano-posts or pillars) that form particular phase distributions, which provides the required phase distributions for different wavelengths. The meta-surface guides different incident wavelengths to their own target positions, which is also known as color routing. The target positions here represent the different color filters in the color filter layer.

[0045] For example, after adjusting the phase distributions of the incident wavelengths, a particular phase distribution is transmitted to a red color filter allowing red light to pass through, and then the red light transmitted to the photodiode(s) located under the red color filter, so that an electrical signal of red light can be detected. In this case, the particular phase distribution for the red color filter can be understood as being used for red light.

[0046] The imaging device of the present disclosure considers that different incidence angles of incident light in a CMOS array would affect the quantum efficiencies of different green pixels in a Bayer array. The positions of the nano-posts in the meta-surface layer of the present disclosure can be adjusted by the described equations, which are calculated based on the incidence angles of the incident light and the azimuthal angle of the nano-posts. The described meta-surface layer can provide similar amounts of quantum efficiencies between different green pixels in the Bayer array, thereby avoiding the occurrence of channel separation between different green pixels and increasing the performance of the imaging device. The channel separation indicates that the quantum efficiencies of the photodiodes in the different green pixels are unbalanced.

[0047] [Fig. 1] is a perspective view of an imaging device 100 when incident light L does not occur at normal incidence, according to some embodiments of the present disclosure. In other words, the incident light L of [Fig. 1] is oblique to the upper surface of a meta-surface layer 150. [Fig. 2] is a side view of a portion of the imaging device 100 of [Fig. 1]. More specifically, [Fig. 2] essentially illustrates a half portion (such as a blue region BR and a first green region GR1, as well as their underlying components) of the imaging device 100 of [Fig. 1]. [Fig. 3] is a top view of a meta-surface layer of [Fig. 1].

[0048] In Figures 1 and 2, the imaging device 100 includes a photoelectric conversion layer 110. The photoelectric conversion layer 110 includes a substrate 112, a plurality of deep trench isolations (DTIs) 114, and a plurality of photodiodes 116.

[0049] As illustrated in [Fig. 2], the DTIs 114 and the photodiodes 116 are integrated into the substrate 112, and each of the photodiodes 116 is disposed between two DTIs 114. In some embodiments, the substrate 112 may be a single structure shared by all the DTIs 114 and the photodiodes 116 of the imaging device 100. The DTIs 114 are configured to prevent light interference between adjacent photodiodes 116. The photodiodes 116 are configured to sense incident light L and generate intensity signals based on the intensity of the incident light L propagating thereon. The intensity signals form the image signals.

[0050] In some embodiments, substrate 112 may be a semiconductor substrate, an organic photoelectric conversion substrate, a substrate semiconductor on insulator (SOI) or other suitable substrate. In other embodiments, transistors, photodiodes, or the like may be formed in the active regions (defined by the DTIs 114) of the substrate 112. In some embodiments, additional isolation structures may be applied as an alternative, such as shallow trench isolations (STIs) and local oxidation structures of silicon (LOCOS). In some embodiments, the DTIs 114 may be formed by a photolithography process.

[0051] In Figures 1 and 2, the imaging device 100 includes an anti-reflective layer 120 disposed on the substrate 112. The anti-reflective layer 120 is configured to decrease reflection of light transmitted to the underlying photodiodes 116. In some embodiments, the anti-reflective layer 120 may be made of a material comprising silicon oxynitride (SiOxNy, where x and y are between 0 and 1).

[0052] In Figures 1 and 2, the imaging device 100 comprises a color filter layer 130 disposed on the antireflection layer 120. The color filter layer 130 comprises a plurality of color filters, for example a blue filter B, a first green filter G1, a second green filter G2 and a red filter R. The color filter layer 130 is arranged in a 2x2 matrix, visible in a top view. In some embodiments, the color filter layer 130 is arranged in a Bayer matrix. As illustrated in [Fig. 2], the color filter layer 130 further comprises a plurality of grid structures 132 and a plurality of light shielding structures 135. The grid structures 132 are arranged adjacent to the color filters. For example, as illustrated in [Fig.2], the grid structures 132 are arranged adjacent to the blue filter B and the first green filter GL. The grid structures 132 are configured to isolate the light within the particular unit to serve as a light trapping function. Each of the light shielding structures 135 is integrated into one of the grid structures 132. The light shielding structures 135 are configured to prevent the underlying photodiodes 116 from receiving additional light from different colored lights in the adjacent components.

[0053] In some embodiments, each filter (such as blue filter B, first green filter G1, second green filter G2, and red filter R) of color filter layer 130 allows a predetermined range of wavelengths of light to pass through it. For example, red filter R allows wavelengths of light between about 620 nm and about 750 nm (red light) to be transmitted to the corresponding photodiodes 116, first green filter G1 and second green filter G2 allow wavelengths of light between about 495 nm and about 570 nm (green light) to be transmitted to the corresponding photodiodes 116, and blue filter B allows wavelengths of light between about 450 nm and about 495 nm (blue light) to be transmitted to the corresponding photodiodes 116. The first green filter G1 may be the same as the second green filter G2.

[0054] In some embodiments, the height of the color filter layer 130 is between 0.3 pm and 2.0 pm, for example 0.5, 0.9, 1.2, 1.5, or 1.8 pm. In some embodiments, the height of the grid structure 132 may be greater than or equal to the height of the light shielding structure 135, depending on the design requirements of the imaging device 100. In some embodiments, the height of the light shielding structure 135 is between about 0.005 pm and about 2.000 pm. In some embodiments, the grid structures 132 may be made of a material comprising a transparent dielectric material.In some embodiments, the light shielding structures 135 may be made of a material comprising opaque metals such as tungsten (W), aluminum (Al), an opaque metal nitride, an opaque metal oxide, other suitable materials, or combinations thereof.

[0055] In the present description, a "pixel" is determined by a color filter, and each pixel may correspond to at least one photodiode. More specifically, in the cross-sectional view of [Fig. 2], a pixel PI is determined by the blue filter B of the color filter layer 130 and the pixel PI corresponds to two photodiodes 116. The photodiodes 116 under the blue filter B are arranged in a 2x2 matrix (such as quadruple photodiodes (DPD)). In the case where the photodiodes 116 are arranged in the 2x2 matrix, the blue filter B corresponds to four photodiodes 116. As illustrated in [Fig. 2], the pixel PI has a left pixel Pl_a and a right pixel Pl_b, in which each of the left pixel Pl_a and right pixel Pl_b corresponds to a single photodiode 116.

[0056] Similarly, in the cross-sectional view of [Fig. 2], a pixel P2 is determined by the first green filter G1 of the color filter layer 130 and the pixel P2 corresponds to two photodiodes 116. The photodiodes 116 under the first green filter G1 are arranged in a 2x2 matrix. As illustrated in [Fig. 2], the pixel P2 has a left pixel P2_a and a right pixel P2_b, wherein each of the left pixel P2_a and right pixel P2_b corresponds to a single photodiode 116. It will be understood that each of the DTIs 114 may serve as a boundary for the left pixel Pl_a, the right pixel Pl_b, the left pixel P2_a or the right pixel P2_b. Each of the grid structures 132 may serve as a boundary for a different pixel (such as the pixel P1 or the pixel P2). Each center line (not shown) of the grid structure 132 may define the boundaries of different pixels. In other words, the grid structure 132 in the middle of [Fig.2] spans the boundary of pixel PI and pixel P2. In some modes of . embodiment, a dimension of each of the pixels PI or P2 is between approximately 400 nm and approximately 700 nm, for example 500 or 600 nm.

[0057] It will be noted that, in each pixel (such as pixel P1 or pixel P2), the photodiodes 116 may be arranged in an mxn matrix, in which m and n are positive integers which may be the same or different, but the present description is not limited to this. For example, the photodiodes 116 under the blue filter B may be arranged in a 1x2 matrix (such as dual photodiodes (DPD)), and the photodiodes 116 under the first green filter G1 may be arranged in a 1x2 matrix. In the case where the photodiodes 116 are arranged in the 1x2 matrix, the blue filter B corresponds to two photodiodes 116 and the first green filter G1 also corresponds to two photodiodes 116.

[0058] In Figures 1 and 2, the imaging device 100 has a dielectric layer 140 (also called a spacer layer) disposed on the color filter layer 130. As illustrated in [Fig. 2], the dielectric layer 140 covers the upper portions 131 of the color filter layer 130 (e.g., the blue filter B and the first green filter Gl) and the grid structures 132. In the embodiment of the imaging device 100, the dielectric layer 140 may provide the necessary path for incident light L of different diffractions to reach their respective targets (different color filters in the color filter layer 130). In some embodiments, the upper portion 131 of each color filter in the color filter layer 130 has a trapezoidal shape, with its upper surface smaller than its lower surface.

[0059] In some embodiments, the thickness of the dielectric layer 140 is between about 0.1 μm and about 0.5 μm, for example, 0.2, 0.3, or 0.4 μm. The dimension of the dielectric layer 140 may be adjusted depending on the design requirements of the imaging device 100. In some embodiments, the dielectric layer 140 may be made of a material including silicon oxide, silicon nitride, silicon carbide, silicon carbonitride (SiCN), silicon oxynitride, silicon oxynitrocarbide, tetraethyl orthosilicate (TEOS), a low dielectric constant k material, or any other suitable material.

[0060] In Figures 1 and 2, the imaging device 100 has a meta-surface layer 150 disposed on the dielectric layer 140. In other words, the meta-surface layer 150 is disposed above the color filter layer 130. As shown in Figures 1 to 3, the meta-surface layer 150 has a blue region BR, a first green region GR1, a second green region GR2, and a red region RR, and these regions are arranged in a 2x2 matrix. More specifically, the blue region BR is above the underlying blue filter B, the first green region GR1 is above the first underlying green filter Gl, the second green region GR2 is above the second underlying green filter G2, and the red region RR is above the underlying red filter R. In some embodiments, a dimension of each of the blue region BR, the first green region GR1, the second green region GR2, and the red region RR is between about 400 nm and about 700 nm. In some embodiments, the height of the meta-surface layer is between about 0.7 pm and about 1.5 pm, for example, 1.2 pm.

[0061] In Figures 1 to 3, the meta-surface layer 150 comprises a filler material 152 and a plurality of nanostructures 154. The filler material 152 laterally surrounds the nanostructures 154. The nanostructures 154 comprise a plurality of peripheral nanoposts 154A and a plurality of central nanoposts 154B. More specifically, the peripheral nanoposts 154A are located at the corners of each of the blue region BR, the first green region GR1, the second green region GR2 and the red region RR. In each of the blue region BR, the first green region GR1, the second green region GR2 and the red region RR, one of the central nanoposts 154B is surrounded by the plurality of peripheral nanoposts 154A.

[0062] As illustrated in [Fig. 2], the peripheral nano-post 154A in the middle of [Fig. 2] spans the boundaries of the blue region BR and the first green region GR1, and the central nano-posts 154B do not share adjacent colored regions. Each of the peripheral nano-posts 154A aligns with each of the grid structures 132, for example, a center line of the peripheral nano-post 154A aligns with a center line of the grid structure 132. In order to more clearly illustrate the configuration of the nanostructures 154, the middle of the filler material 152 of [Fig. 1] is illustrated by dotted lines.

[0063] In embodiments of the imaging device 100, the nanostructures 154 are cylindrical columns. In some embodiments, the central nanopost 154B and the peripheral nanopost 154A have a round, rectangular, or triangular profile in top view. In some alternative embodiments, in each of the blue region BR, the first green region GR1, the second green region GR2, and the red region RR, a plurality of intermediate nanoposts (not shown) may be disposed between the central nanopost 154B and the peripheral nanoposts 154A. In some embodiments, the intermediate nanoposts are arranged in a circle, and the central nanopost 154B is arranged in a cylindrical configuration.

[0064] Refer to Figures 2 and 3. The central nano-post 154B in the blue region BR has an offset value OBxi and OByi relative to the central point BR_C of the blue region BR. The central nano-post 154B in the first green region GR1 has an offset value OGlxi and OGlyi relative to the central point GR1_C of the first green region GR1. The central nano-post 154B in the second green region GR2 has an offset value 0G2xi and OG2yi relative to the central point GR2_C of the second green region GR2. The central nano-post 154B in the red region RR has an offset value ORxi and ORyi relative to the central point RR_C of the red region RR. The offset values ​​OBxi, OGlxi, 0G2xi and ORxi represent the offset values ​​in the X direction when the incident light angle L is oblique to the upper surface of the meta-surface layer 150.The shift values ​​OByi, OGlyi, OG2yi and ORyi represent the shift values ​​in the Y direction when the incident light angle L is oblique to the upper surface of the meta-surface layer 150. In some embodiments, the shift values ​​OBxi, OGlxi, OG2xi and ORxi and the shift values ​​OByi, OGlyi, OG2yi and ORyi mentioned above may be in the range of 1 / 5 of the pixel dimension PI (see [Fig. 2]). The structure of the nanostructures 154 will be explained in detail with [Fig. 4B] below.

[0065] [Fig.4A] is a top view of a structure 151a of a meta-surface layer when incident light L occurs at normal incidence according to some embodiments of the present disclosure. [Fig.5A] is a coordinate illustrating the definitions of various parameters when the incident light L occurs at normal incidence. By "normal incidence" is meant herein that the angle of incidence of the incident light L is parallel to the Z direction.

[0066] In the three-dimensional coordinates of [Fig.5A], 0 is the angle of incidence of the incident light L. Note that the angle of incidence 0 is equal to 0 degrees when the angle of incidence of the incident light L is perpendicular to the XY plane, and that the structure 151a illustrated in [Fig.4A] corresponds to the condition of normal incidence of the incident light L. In other words, a normal vector of the XY plane is parallel to the angle of incidence of the incident light L when the angle of incidence 0 is equal to 0.

[0067] [Fig.4B] is a top view of a structure 151b of the meta-surface layer 150 of [Fig.1]. Figures 5B to 5D are coordinates illustrating the definitions of various parameters when incident light L does not occur at normal incidence. It will be understood that the differences in conditions between Figures 4A and 4B are the angles of incidence of the incident light L, so that the structures 151a and 151b are different. More specifically, the meta-surface layer of [Fig.4A] is subject to the condition that the incident light L is at normal incidence, and the meta-surface layer of [Fig.4B] is subject to the condition that the incident light L is not at normal incidence.

[0068] When the incident light L is not at normal incidence (i.e., the angle of incidence of the incident light L is oblique to the upper surface of the meta-surface layer 150), the offset values ​​of the central nanoposts 154B in the first green region GR1 and the second green region GR2 have additional offset values ​​compared to the structure 151a of [Fig. 4A]. Referring to Figures 4A and 4B, the structural differences between Figures 4A and 4B are the positions of the central nanopost 154B in the first green region GR1 and the central nanopost 154B in the second green region GR2.

[0069] Referring to [Fig.4A]. In the blue region BR, the central nano-post 154B shifts from the central point BR_C by an offset distance to be located at an offset position BR_P1, in which the offset distance is defined by a horizontal offset BR_dxl in the X-axis direction and a longitudinal offset BR_dyl in the Y-axis direction. In the first green region GR1, the central nano-post 154B shifts from the central point GR1_C by an offset distance to be located at an offset position GR1_P1, in which the offset distance is defined by a horizontal offset GRl_dxl in the X-axis direction and a longitudinal offset GRl_dyl in the Y-axis direction.In the second green region GR2, the central nano-post 154B shifts from the center point GR2_C by an offset distance to an offset position GR2_P1, wherein the offset distance is defined by a horizontal offset GR2_dxl in the X-axis direction and a longitudinal offset GR2_dyl in the Y-axis direction. In the red region RR, the central nano-post 154B shifts from the center point RR_C by an offset distance to an offset position RR_P1, wherein the offset distance is defined by a horizontal offset RR_dxl in the X-axis direction and a longitudinal offset RR_dyl in the Y-axis direction. Note that "horizontal offset" in this description represents an offset in a direction parallel to the X-axis, and "longitudinal offset" in this description represents an offset in a direction parallel to the Y-axis.In some embodiments, the above-mentioned horizontal and longitudinal offsets may be in the range of 1 / 5 of the dimension of the pixel PI (see [Fig.2]).

[0070] Referring to [Fig.4B]. In the first green region GR1, the central nano-post 154B shifts from the offset position GR1_P1 by an additional offset distance to be located at an offset position GR1_P2, in which the additional offset distance is defined by a horizontal offset GR1_dx2 in the X-axis direction and a longitudinal offset GR1_dy2 in the Y-axis direction. In the second green region GR2, the central nano-post 154B shifts from the offset position GR2_P1 by an additional offset distance to be located at an offset position GR2_P2, in which the additional offset distance is defined by a horizontal offset GR2_dx2 in the X-axis direction and a longitudinal offset GR2_dy2 in the Y-axis direction.

[0071] Note that the horizontal offset BR_dxl and the longitudinal offset BR_dyl illustrated in [Fig.4B] are respectively equal to the offset values ​​OBxi and OByi illustrated in [Fig.3]. The horizontal offset GRl_dxl and the horizontal offset GRl_dx2 illustrated in [Fig.4B] are equal to the offset value OGlxi illustrated in [Fig.3], and the longitudinal offset GRl_dyl plus the longitudinal offset GRl_dy2 are equal to the offset value OGlyi illustrated in [Fig.3]. The horizontal offset GR2_dxl plus the horizontal offset GR2_dx2 illustrated in [Fig.4B] are equal to the offset value OG2xi illustrated in [Fig.3], and the longitudinal offset GR2_dyl plus the longitudinal offset GR2_dy2 are equal to the offset value OG2yi illustrated in [Fig.3]. The horizontal offset RR_dxl and the longitudinal offset RR_dyl illustrated in [Fig.4B] are respectively equal to the offset values ​​ORxi and ORyi illustrated in [Fig.3].

[0072] In the embodiment of [Fig.4B], the horizontal offset GRl_dx2 in the first green region GR1 is the same as the horizontal offset GR2_dx2 in the second green region GR2, and the longitudinal offset GRl_dy2 in the first green region GR1 is the same as the longitudinal offset GR2_dy2 in the second green region GR2.

[0073] Referring to Figures 5B to 5D, 0 is the angle of incidence of the incident light L and 0 is the azimuthal angle. In the case where the incident light L is oblique to the upper surface of the meta-surface layer 150 (see [Fig. 3]), the angle of incidence 0 of the incident light L is no longer equal to 0. Therefore, the angle of incidence 0 can be defined as an included angle between the direction of incidence of the incident light L and the normal vector to the coordinate of the XY plane. The azimuthal angle corresponds to the angle included in the coordinate of the XY plane.

[0074] Referring to the equations mentioned below, DGR and DGB are both functions of the incidence angle 0 and the azimuthal angle 0. The incidence angle 0 and the azimuthal angle 0 can be referred to Figures 5B to 5D.

[0075] As illustrated in Figures 5B and 5C, the position (r, 0, 0) and the position (r, 0, 0') have the same incidence angles but different azimuthal angles, wherein 0 is not greater than 35 degrees and 0 is between 0 and 360 degrees, and 0 > 0'. As illustrated in Figures 5B and 5D, the position (r, 0, 0) and the position (r, 0', 0) have the same azimuthal angles but different incidence angles, wherein 0 is not greater than 35 degrees and 0 is between 0 and 360 degrees, and 0' > 0. All conditions under which the incident light L does not occur at normal incidence can be calculated using the equations mentioned above. below. DGR(0, 0) and DGB(0, 0) vary depending on the angle of incidence of the incident light L and the azimuthal angle.

[0076] [Fig.5E] shows an array of the meta-surface layer 150 according to some embodiments of the present disclosure. A "pixel unit" herein consists of a blue region BR, a first green region GR1, a second green region GR2, and a red region RR. The meta-surface layer 150 consists of a plurality of pixel units, as illustrated in [Fig.5E]. [Fig.5E] illustrates a first pixel unit and a second pixel unit adjacent to the first pixel unit. Note that there is a central nano-post 154B in each of the blue region BR, the first green region GR1, the second green region GR2, and the red region RR in each of the first pixel unit and the second pixel unit.

[0077] Referring to Figures 4B and 5E, the horizontal offset GRl_dxl plus the horizontal offset GRl_dx2 in the first green region GR1 is determined as a function of the incidence angle 0 and the azimuthal angle 0 of the first green region GR1, and the longitudinal offset GRl_dyl plus the longitudinal offset GRl_dy2 in the first green region GR1 is also determined as a function of the incidence angle 0 and the azimuthal angle 0 of the first green region GR1. The incidence angle 0 of the first green region GR1 is between a first incident light L (see [Fig.l] and [Fig.5B]) on an upper surface of the first green region GR1 and a line normal to the upper surface of the first green region GR1. Referring to [Fig.5E], the azimuthal angle 0 of the first green region GR1 is between a horizontal axis X of the meta-surface layer 150 which passes through a center C of the meta-surface layer 150 and a first connection line CL1 between the center of the first green region GR1 and the center C of the meta-surface layer 150.

[0078] As illustrated in [Fig.5E], the meta-surface layer 150 further comprises a second pixel unit, the second pixel unit comprising a third green region, the third green region comprising a third central nano-post offset from a center of the third green region by a third longitudinal offset and a third horizontal offset of the third central nano-post, the third longitudinal offset and the third horizontal offset being determined according to an angle of incidence 0, and an azimuthal angle 0j of the third green region. The angle of incidence 0j of the third green region is between a second light incident on an upper surface of the third green region and a line normal to the upper surface of the third green region. The azimuthal angle 0j of the third green region is between the horizontal axis X of the meta-surface layer that passes through the center C of the meta-surface layer 150 and a second connecting line CL2 between the center of the third green region and the center C of the meta-surface layer 150. The longitudinal offset GRl_dyl plus the longitudinal offset GRl_dy2 (see [Fig.4B]) of the central nano-post 154B in the first green region GR1 and the third longitudinal offset of the third central nano-post satisfy the following equation: D gr (0, 0) =D GR (0i, 0j) + A 0^“ + A 0¾ in which 0 is the incidence angle of the first green region and 0 is not equal to 0 degrees, 0 is the azimuthal angle of the first green region, DGR(0, 0) is the longitudinal offset GRl_dy 1 plus the longitudinal offset GRl_dy2 of the first central nanopost, 0; is the incidence angle of the third green region and 0j is not equal to 0 degrees, 0j is the azimuthal angle of the third green region, DGR(0i? 0j) is the third longitudinal offset of the third central nanopost, A0 is a first difference between the incidence angle of the first green region and the incidence angle of the third green region, A0 is a second difference between the azimuthal angle of the first green region and the azimuthal angle of the third green region.

[0079] Figure 5F is a schematic diagram of reference points. Reference point 1 and reference point 2 represent known elements DGR( 0;, 0j) above, and reference point 3 represents the unknown DGR(9, 0) above. Reference point 3 can be obtained by the nearest reference points (such as reference point 1 or reference point 2).

[0080] The horizontal offset GRl_dxl plus the horizontal offset GRl_dx2 (see [Fig.4B]) of the first central nano-post 154B in the first green region GR1 and the third horizontal offset of the third central nano-post satisfy the following equation: D GB (0, 0) = D gb (0], 0j) + A0¾ 1 + A 0^ where DGB( 0, 0 ) is the horizontal offset GRl_dxl plus the horizontal offset GRl_dx2 of the first central nano-post, and DGB( 0, 00 ) is the third horizontal offset of the third central nano-post.

[0081] In some embodiments, 0 is greater than 0 degrees and < 35 degrees, and 0 is between 0 and 360 degrees.

[0082] Once the structure 151b of [Fig.4B] is obtained, the nanostructures 154 (which comprise the peripheral nano-posts 154A and the central nano-posts 154B) are formed in accordance with the structure 151b, as illustrated in [Fig.3]. In In some embodiments, the nanostructures 154 may be formed by any suitable deposition and patterning process, and then the filler material 152 is formed to laterally surround the peripheral nanoposts 154A and the central nanoposts 154B. In another embodiment, the peripheral nanoposts 154A and the central nanoposts 154B are formed by deposition of the filler material 152, followed by etching multiple holes in the filler material 152. In other words, the nanostructures 154 may be holes filled with ambient air, and then the material of the nanostructures 154 is formed in the holes.

[0083] In Figures 1-3, in some embodiments, the dimensions (such as diameters) of the nanostructures 154 in top view are between about 120 nm and about 250 nm.The dimensions of the central nano-posts 154B may be equal to or greater than the dimensions of the peripheral nano-posts 154A. Although the nanostructures 154 are illustrated as having circular shapes in top view, the present description is not limited thereto. The nanostructures 154 may have any suitable geometric shape, as long as the necessary phase distribution of the different colored lights can be formed.

[0084] In some embodiments, the nanostructures 154 may be made of a material comprising transparent conductive materials, such as indium tin oxide (ITO), tin oxide (SnO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), antimony tin oxide (ATO), aluminum-doped zinc oxide (AZO), titanium dioxide (TiO2), other suitable materials, or combinations of these materials. In some embodiments, the filler material 152 may be comprised of transparent resins, such as polyethylene terephthalate (PET) resins, polycarbonate (PC) resins, polyimide (PI) resins, polymethyl methacrylates (PMMA), polystyrene resins, other suitable resins, or combinations thereof.

[0085] In the above equations, each of DGr and DGb has a positive shift and a negative shift. The positive shift of DGR is defined by a shift from the green region (such as the first green region GR1 or the second green region GR2) to the red region RR, and the positive shift of DGB is defined by a shift from the green region (such as the first green region GR1 or the second green region GR2) to the blue region BR. More specifically, in the first green region GR1 of [Fig.4B], the longitudinal shift GRl_dyl and the longitudinal shift GRl_dy2 can both be considered the "positive shifts" of DGR and the horizontal shift GRl_dxl and the horizontal shift GRl_dx2 can be considered the "positive shifts" of DGB. In the second region green GR2 of [Fig.4B], the horizontal shift GR2_dxl and the horizontal shift GR2_dx2 can be considered as "positive shifts" of DGR and the longitudinal shift GR2_dyl and the longitudinal shift GR2_dy2 can be considered as "positive shifts" of DGB.

[0086] In the embodiment of [Fig.3], all of the horizontal offset GRl_dxl, the horizontal offset GRl_dx2, the longitudinal offset GRl_dyl and the longitudinal offset GRl_dy2 in the first green region GR1 are positive offsets. Similarly, all of the horizontal offset GR2_dxl, the horizontal offset GR2_dx2, the longitudinal offset GR2_dyl and the longitudinal offset GR2_dy2 in the second green region GR2 are positive offsets.

[0087] Figure 6A is a side view of a portion of an imaging device 100a at an angle of incidence θj of the third green region GR3 according to some embodiments of the present description. [Fig.6B] is a side view of a portion of an imaging device 100b at an angle of incidence θ of the first green region GR1 according to some embodiments of the present description.

[0088] As illustrated in [Fig. 6B], an edge of the first green region GR1 is offset from a corresponding edge of the first green filter G1 by an offset distance of the first green region GR1. The color filter 130 has a third green filter G3 (see [Fig. 6A]) adjacent to the first green filter G1 (see [Fig. 6B]). The third green region GR3 is above the third green filter G3, and an edge of the third green region GR3 is offset from a corresponding edge of the third green filter G3 by an offset distance of the third green region GR3, as illustrated in [Fig. 6A]. The offset distance of the first green region GR1 and the offset distance of the third green region GR3 satisfy the following equation: 8(0) = 8(00 + ^61 wherein S(0) is the offset distance of the first green region GR1, and θ(0;) is the offset distance of the third green region GR3. In some embodiments, the offset distance of the first green region GR1 is between 0 and 300 nm.

[0089] In some embodiments, the offset distance S(0) is between about -P 1 / 2 and about P1 / 2. In some embodiments, the offset distance S(0) is 0 nm when 0 is 0 degrees. In some embodiments, the offset distance S(0) is 72 nm when 0 is 7.5 degrees. In some embodiments, the offset distance S(0) is 157 nm when 0 is 15 degrees. In some embodiments, the offset distance S(0) is 209 nm when 0 is 22.5 degrees. In some embodiments, the offset distance S(0) is 291 nm when 0 is 30 degrees.

[0090] A method for manufacturing the imaging device 100 comprises the following steps. The photoelectric conversion layer 110 is formed. The antireflection layer 120 is formed on the photoelectric conversion layer 110. The color filter layer 130 is formed on the antireflection layer 120. The dielectric layer 140 is formed on the color filter layer 130. The meta-surface layer 150 (which comprises the peripheral nano-posts 154A and the central nano-posts 154B) is formed on the dielectric layer 140, the meta-surface layer 150 being formed according to the structure 151b.

[0091] [Fig.7] is a top view of a meta-surface layer 750 according to some embodiments of the present disclosure. The differences between the meta-surface layer 750 of [Fig. 7] and the meta-surface layer 150 of [Fig. 3] are the positions of the central nano-posts 154B in the blue region BR, the first green region GR1, the second green region GR2, and the red region RR, respectively. The central nano-posts 154B of [Fig. 7] have negative offsets. In the present disclosure, the negative offset of DGR is defined by a shift of the green region (such as the first green region GR1 or the second green region GR2) away from the red region RR, and the negative offset of DGb is defined by a shift of the green region (such as the first green region GR1 or the second green region GR2) away from the blue region BR. More specifically, in the first green region GR1 of [Fig.7], the longitudinal shift GRl_dyl and the longitudinal shift GRl_dy2 can both be considered as the "negative shifts" of DGR and the horizontal shift GRl_dxl and the horizontal shift GRl_dx2 can both be considered as the "negative shifts" of DGB. In the second green region GR2 of [Fig.7], the horizontal shift GR2_dxl and the horizontal shift GR2_dx2 can both be considered as the "negative shifts" of DGR and the longitudinal shift GR2_dyl and the longitudinal shift GR2_dy2 can both be considered as the "negative shifts" of DGB.

[0092] In the embodiment of [Fig.7], all of the horizontal offset GRl_dxl, the horizontal offset GRl_dx2, the longitudinal offset GRl_dyl and the longitudinal offset GRl_dy2 in the first green region GR1 are negative offsets. Similarly, all of the horizontal offsets GR2_dxl, the horizontal offsets GR2_dx2, the longitudinal offsets GR2_dyl and GR2_dy2 in the second green region GR2 are negative offsets.

[0093] Reference will be made to the imaging device 100 of [Fig. 2]. In certain embodiments, the refractive index of the nanostructures 154 (which comprises the nano peripheral posts 154A and the central nano-posts 154B) is greater than the refractive index of the filler material 152. In some embodiments, the refractive index of the peripheral nano-posts 154A is the same as the refractive index of the central nano-posts 154B. In some embodiments, the refractive index of the peripheral nano-posts 154A is between about 1.8 and about 3.5, for example, 2.0, 2.5 or 3.0. In some embodiments, the refractive index of the central nano-post 154B is between about 1.8 and about 3.5, for example, 2.0, 2.5 or 3.0. In some embodiments, the refractive index of the filler material 152 is between about 1.0 and about 1.6, for example 1.2 or 1.4. In some embodiments, the filler material 152 may be air.It should be noted that when the nanostructures 154 are surrounded by ambient air (the refractive index of the filling material 152 is 1), the larger difference between the refractive indices can be realized to generate a much broader phase distribution, so that the incident light L can be more easily separated based on the different wavelengths. In some embodiments, the radii of the central nano-pole 154B in each of the blue region BR, the first green region GR1, the second green region GR2, and the red region RR are different from each other. The dimensions of each of the central nano-poles 154B can be adjusted according to the design requirements of the imaging device 100.

[0094] Reference will again be made to the imaging device 100 of [Fig. 2]. In some embodiments, the refractive index of the dielectric layer 140 is lower than the refractive index of the nanostructures 154. In some embodiments, the refractive index of the dielectric layer 140 is between about 1.0 and about 1.6, for example 1.2 or 1.4. In some embodiments, the refractive index of each filter (such as the blue filter B, the first green filter Gl, the second green filter G2 and the red filter R) of the color filter layer 130 is greater than the refractive index of the grid structures 132. In some embodiments, the refractive index of each filter of the color filter layer 130 is between about 1.4 and about 2.3, for example 1.6, 1.8, 2.0 or 2.2.In some embodiments, the refractive index of the grid structures 132 is between about 1.0 and about 1.3, for example 1.1 or 1.2.

[0095] The present disclosure takes into account the condition that the incident light L does not occur at normal incidence and provides a method for forming the meta-surface layer, wherein the central nano-post(s) of the green region(s) has (have) an additional offset distance(s) relative to the central nano-posts of the blue region and the red region. The additional offset distance(s) can be calculated using the equations mentioned above. The meta-surface layer of the present disclosure allows for a wide range of incident light angles and provides balanced amounts of quantum efficiency for different green pixels in the Bayer matrix. The described meta-surface layer can provide similar amounts of quantum efficiency between different green pixels, thereby avoiding the occurrence of channel separation between different green pixels and increasing the performance of the imaging device.

[0096] The present description has been made as indicated above, but it is not used to limit the present description. The person skilled in the art will be able to make various modifications, substitutions and alterations without departing from the spirit and scope of the present description. Therefore, the scope of protection of the present description is subject to the scope of the claim appended to the application and its equivalent structures.

Claims

Claims

1. An imaging device, comprising: - a plurality of photodiodes; - a color filter layer over the plurality of photodiodes, wherein the color filter layer comprises a blue filter, a red filter, a first green filter and a second green filter;and - a meta-surface layer above the color filter layer and comprising a first pixel unit, the first pixel unit comprising a blue region above the blue filter, a red region above the red filter, a first green region above the first green filter and a second green region above the second green filter, wherein the first green region comprises a first central nanopost offset from a center of the first green region by a first longitudinal offset in a Y-axis direction and a first horizontal offset in an X-axis direction of the first central nanopost in top view, and wherein the second green region comprises a second central nanopost offset from the center of the second green region by a second longitudinal offset in the Y-axis direction and a second horizontal offset in the X-axis direction of the second central nanopost in top view.;

2. The imaging device of claim 1, wherein the first longitudinal offset and the first horizontal offset are determined based on an incident angle and an azimuthal angle of the first green region, wherein the incident angle of the first green region is between first light incident on an upper surface of the first green region and a line normal to the upper surface of the first green region, and wherein the azimuthal angle of the first green region is between a horizontal axis of the meta-surface layer that passes through the center of the meta-surface layer and a first connecting line between the center of the first green region and the center of the meta-surface layer.

3. The imaging device of claim 2, wherein the meta-surface layer further comprises a second pixel unit,

4. wherein the second pixel unit comprises a third green region, the third green region comprising a third central nano-post offset from a center of the third green region by a third longitudinal offset in the Y-axis direction and a third horizontal offset in the X-axis direction of the third central nano-post in top view, the third longitudinal offset and the third horizontal offset being determined based on an angle of incidence and an azimuthal angle of the third green region, wherein the angle of incidence of the third green region is between a second light incident on an upper surface of the third green region and a line normal to the upper surface of the third green region,wherein the azimuthal angle of the third green region is between the horizontal axis of the meta-surface layer which passes through the center of the meta-surface layer and a second connecting line between the center of the third green region and the center of the meta-surface layer, and, wherein the first longitudinal offset of the first central nano-post and the third longitudinal offset of the third central nano-post satisfy the following equation: DGR(0, 0) = 0^(0, 0j) + A0^+ A 0> in which 0 is the incidence angle of the first green region and 0 is not equal to 0 degrees, 0 is the azimuthal angle of the first green region, DGR(0, 0) is the first longitudinal offset of the first central nano-pole, 0j is the incidence angle of the third green region and 0j is not equal to 0 degrees, 0j is the azimuthal angle of the third green region, DqR( 8$, 0j) is the third longitudinal offset of the third central nano-pole, A0 is a first difference between the incidence angle of the first green region and the incidence angle of the third green region, A0 is a second difference between the azimuthal angle of the first green region and the azimuthal angle of the third green region. The imaging device of claim 3, wherein the first horizontal offset of the first central nano-post and the third horizontal offset of the third central nano-post satisfy the following equation: DGB(e, 0) =0^(¾ 0j) + Ae^+ a 0^, in which DGB( 0,0) is the first horizontal offset of the first central nano-post, and DGB( 0i5 0j ) is the third horizontal offset of the third central nano-post.

5. The imaging device of claim 4, wherein an edge of the first green region is offset from a corresponding edge of the first green filter by a first green region offset distance, the color filter layer includes a third green filter adjacent to the first green filter, the third green region is above the third green filter, and an edge of the third green region is offset from a corresponding edge of the third green filter by a third green region offset distance, and wherein the first green region offset distance and the third green region offset distance satisfy the following equation: 8(6)=8(^) + A og, wherein g(0) is the first green region offset distance, and S( 0j ) is the third green region offset distance, and wherein the first green region offset distance is 0 to 300 nm,0 is greater than 0 degrees and < 35 degrees, and 0 is between 0 and 360 degrees.,

6. An imaging device according to any one of claims 1 to 5, wherein the meta-surface layer further comprises a plurality of peripheral nano-posts and a filler material, the peripheral nano-posts being located at the corners of the blue region, the red region, the first green region and the second green region, the filler material laterally surrounding the first central nano-post and the second central nano-post, the refractive index of the filler material being between 1.0 and 1.6, wherein the imaging device further comprises a dielectric layer, the dielectric layer is disposed between the dielectric layer and the second central nano-post. color filters and the blue filter, the red filter, the first green filter and the second green filter, and wherein a dimension of each of the blue region, the red region, the first green region and the second green region is between 400 nm and 700 nm, wherein a refractive index of the first central nano-pole is between 1.8 and

7. 3, J. An imaging device according to any one of claims 1 to 6, wherein the first longitudinal offset of the first central nanopost is in the range of 1 / 5 of a dimension of the first green filter, and the first horizontal offset of the first central nanopost is in the range of 1 / 5 of the dimension of the first green filter.

8. The imaging device of any one of claims 1 to 7, wherein the first longitudinal offset and the first horizontal offset comprise positive offsets, wherein the second longitudinal offset and the second horizontal offset comprise positive offsets, wherein the positive offset of the first longitudinal offset is defined by an offset from the first green region to the red region, and the positive offset of the first horizontal offset is defined by an offset from the first green region to the blue region, and wherein the positive offset of the second longitudinal offset is defined by an offset from the second green region to the blue region, and the positive offset of the second horizontal offset is defined by an offset from the second green region to the red region.

9. An imaging device according to any one of claims 1 to 7, wherein the first longitudinal offset and the first horizontal offset comprise negative offsets, wherein the second longitudinal offset and the second horizontal offset comprise negative offsets, wherein the negative offset of the first longitudinal offset is defined by an offset of the first green region away from the red region, and the negative offset of the first horizontal offset is defined by an offset of the first green region away from the blue region, and wherein the negative offset of the second longitudinal offset is defined by an offset of the second green region away from the blue region. of the blue region, and the negative offset of the second horizontal shift is defined by an offset of the second green region away from the red region.

10. A method of manufacturing an imaging device, comprising: - providing a plurality of photodiodes; - forming a color filter layer above the plurality of photodiodes, the color filter layer comprising a blue filter, a red filter, a first green filter and a second green filter;and - forming a meta-surface layer above the color filter layer, the meta-surface layer comprising a first pixel unit, the first pixel unit comprising a blue region above the blue filter, a red region above the red filter, a first green region above the first green filter, and a second green region above the second green filter, the first green region comprising a first central nano-post, the second green region comprising a second central nano-post, and forming the meta-surface layer comprising: forming the first central nano-post offset from the center of the first green region by a first longitudinal offset in a Y-axis direction and a first horizontal offset in a X-axis direction of the first central nano-post in top view;and forming the second central nano-post offset from the center of the second green region by a second longitudinal offset in the Y-axis direction and a second horizontal offset in the X-axis direction of the second central nano-post in top view.;

Images