Optical device

Abstract

To provide an optical device having a plurality of meta units, which can provide better optical aberration and improve image quality.SOLUTION: An optical device 100 includes a photovoltaic conversion layer 110, an underlayer 130, an anti-reflective layer 140, and a plurality of meta units 150, and the underlayer is disposed on the photovoltaic conversion layer, the anti-reflective layer is disposed on the underlayer, the meta units are disposed above the photovoltaic conversion layer, in the photovoltaic conversion layer, each of the meta units includes a top TP and a bottom BP, and the projection onto the bottom photovoltaic conversion layer is within the projection onto the top photovoltaic conversion layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to optical devices. More specifically, the present disclosure relates to a T-shaped meta unit. [Background technology]

[0002] In the field of complementary metal oxide semiconductor (CMOS) image sensors (also called CIS), the focal length and optical aberration of the optical device can affect the image quality. The focal length of the light can affect the size of the optical device. If the light consisting of various wavelengths is not properly synchronized, the image quality will be poor. Therefore, it is necessary to improve the image quality of the optical device. Summary of the Invention

[0003] The present disclosure provides various optical devices having multiple meta units. The multiple meta units are embedded in each of the optical devices. Each of the meta units has a top and a bottom, and the surface area of ​​the top is larger than the surface area of ​​the bottom. The meta units of the present disclosure provide better optical aberration correction, which can improve the image quality of the optical devices.

[0004] One aspect of the present disclosure is to provide an optical device, the optical device including a photovoltaic conversion layer, an underlayer, an anti-reflection layer, and a plurality of meta units, the underlayer disposed on the photovoltaic conversion layer, the anti-reflection layer disposed on the underlayer, and the meta units disposed above the photovoltaic conversion layer, where each of the plurality of meta units includes a top and a bottom, and where a projection of the bottom onto the photovoltaic conversion layer is inside a projection of the top onto the photovoltaic conversion layer.

[0005] In some embodiments of the present disclosure, the top of each of the plurality of metaunits is embedded in the anti-reflective layer and the bottom of each of the plurality of metaunits is embedded in the underlayer.

[0006] In some embodiments of the present disclosure, the shape of the top of each of the plurality of metaunits comprises a rectangle when viewed from the side, the shape of the bottom of each of the plurality of metaunits comprises a rectangle when viewed from the side, and the top width of the top is greater than the bottom width of the bottom.

[0007] In some embodiments of the present disclosure, the projections of each of the plurality of meta units onto the photovoltaic layer are spaced apart from one another.

[0008] In some embodiments of the present disclosure, the tops of the meta units are joined to form a continuous top.

[0009] In some embodiments of the present disclosure, a top height of the top of each of the plurality of metaunits is less than a bottom height of the bottom of each of the plurality of metaunits.

[0010] In some embodiments of the present disclosure, the shape of each of the multiple metaunits is circular, square, or rectangular when viewed from above, and the shape of the upper portion of each of the multiple metaunits is rectangular or trapezoidal when viewed from the side.

[0011] In some embodiments of the present disclosure, each of the meta units has a T-shape or a cross shape when viewed from above, and a trapezoid shape when viewed from the side.

[0012] In some embodiments of the present disclosure, the shape of the upper portion of each of the plurality of meta units comprises a trapezoid when viewed from the side, a first upper width of the trapezoid is smaller than a second upper width of the trapezoid, and a base angle of the trapezoid is in the range of 30 to 90 degrees.

[0013] In some embodiments of the present disclosure, the shape of the upper portion of each of the plurality of meta units comprises a trapezoid when viewed from the side, a first upper width of the trapezoid is greater than a second upper width of the trapezoid, and one base angle of the trapezoid is in the range of 90 to 135 degrees.

[0014] In some embodiments of the present disclosure, the photoelectric conversion layer includes a first photodiode, a second photodiode, and a deep trench insulation disposed between the first photodiode and the second photodiode, and the meta units include a first meta unit disposed above the first photodiode, a second meta unit disposed above the second photodiode, and a third meta unit disposed above the deep trench isolation, and the first meta unit, the second meta unit, and the third meta unit are different in size from one another.

[0015] In some embodiments of the present disclosure, the meta unit is a two-dimensional transition metal dichalcogenide, such as ZrO2, TiO2, Si x N y , ITO, Si, a-Si, p-Si, III-V semiconductor compounds, or combinations thereof, where x and y are positive integers, x ranging from 1 to 3, and y ranging from 1 to 4.

[0016] In some embodiments of the present disclosure, the metaunits are arranged in two or three layers, with the bottom layer of metaunits being completely embedded in an underlayer.

[0017] In some embodiments of the present disclosure, the arrangement of the multiple metaunits is a matrix arrangement, a polygonal arrangement, a concentric circle, or random.

[0018] In some embodiments of the present disclosure, the optical device further includes a color filter layer disposed between the photoelectric conversion layer and the underlayer, and an upper portion of each of the plurality of meta units is embedded in an anti-reflection layer and a bottom portion of each of the plurality of meta units is embedded in the underlayer.

[0019] In some embodiments of the present disclosure, the optical device has a bottom surface of each of the plurality of meta units contacting an upper surface of the color filter layer.

[0020] In some embodiments of the present disclosure, the optical device further includes a color filter layer disposed between the photoelectric conversion layer and a front underlayer, the color filter layer including a plurality of gratings and a plurality of color filters, and the projection of the plurality of meta units onto the photoelectric conversion layer partially overlaps the projection of the plurality of gratings onto the photoelectric conversion layer.

[0021] In some embodiments of the present disclosure, the optical device further includes a color filter layer disposed between the photoelectric conversion layer and the underlayer, and the plurality of meta units are embedded in the color filter layer.

[0022] In some embodiments of the present disclosure, the optical device further includes a color filter layer disposed between the photoelectric conversion layer and the underlayer, the color filter layer including a plurality of gratings and a plurality of color filters, and the projection of the plurality of meta units onto the photoelectric conversion layer is spaced apart from the projection of the plurality of gratings onto the photoelectric conversion layer.

[0023] In some embodiments of the present disclosure, the refractive index of the multiple metaunits is greater than the refractive index of the underlayer, which is greater than the refractive index of the antireflective layer, and the refractive index of the multiple metaunits is in the range of 1.4 to 6.5. [Brief description of the drawings]

[0024] Aspects of the present disclosure are best understood from the following detailed description when considered in conjunction with the accompanying drawings, in which: Figure 1 is a schematic diagram of a semiconductor device according to an embodiment of the present invention; [Figure 1] 1 is a cross-sectional view of an optical device according to some embodiments of the present disclosure. [Figure 2A] FIG. 2 is a three-dimensional view of a meta unit of the optical device of FIG. 1. [Figure 2B] This is a side view of the metaunit in FIG. 2A. [Figure 3A] FIG. 13 is a three-dimensional view of a meta unit according to an alternative embodiment of the present disclosure. [Figure 3B] FIG. 3B is a side view of the meta unit of FIG. 3A. [Figure 4A] FIG. 13 is a three-dimensional view of a meta unit according to an alternative embodiment of the present disclosure. [Figure 4B] FIG. 4B is a side view of the meta unit of FIG. 4A. [Diagram 5] FIG. 13 is a three-dimensional view of a meta unit according to an alternative embodiment of the present disclosure. [Figure 6] FIG. 13 is a three-dimensional view of a meta unit according to an alternative embodiment of the present disclosure. [Figure 7] FIG. 13 is a three-dimensional view of a meta unit according to an alternative embodiment of the present disclosure. [Figure 8] FIG. 13 is a three-dimensional view of a meta unit according to an alternative embodiment of the present disclosure. [Figure 9] FIG. 13 is a three-dimensional view of a meta unit according to an alternative embodiment of the present disclosure. [Figure 10] FIG. 13 is a three-dimensional view of a meta unit according to an alternative embodiment of the present disclosure. [Figure 11] FIG. 13 is a three-dimensional view of a meta unit according to an alternative embodiment of the present disclosure. [Figure 12] FIG. 13 is a three-dimensional view of a meta unit according to an alternative embodiment of the present disclosure. [Figure 13] FIG. 13 is a cross-sectional view of an array of meta units according to an alternative embodiment of the present disclosure. [Figure 14] FIG. 13 is a cross-sectional view of an array of meta units according to an alternative embodiment of the present disclosure. [Figure 15] FIG. 13 is a cross-sectional view of an array of meta units according to an alternative embodiment of the present disclosure. [Figure 16] FIG. 13 is a cross-sectional view of an array of meta units according to an alternative embodiment of the present disclosure. [Figure 17] FIG. 13 is a cross-sectional view of an array of meta units according to an alternative embodiment of the present disclosure. [Figure 18] FIG. 2 is a top view of an array of metaunits according to an embodiment of the present disclosure. [Figure 19] FIG. 2 is a top view of an array of metaunits according to an embodiment of the present disclosure. [Figure 20] FIG. 2 is a top view of an array of metaunits according to an embodiment of the present disclosure. [Figure 21] FIG. 2 is a top view of an array of metaunits according to an embodiment of the present disclosure. [Figure 22] FIG. 2 is a cross-sectional view of an optical device according to an embodiment of the present disclosure. [Figure 23A] FIG. 2 is a top view of a color filter layer according to an embodiment of the present disclosure. [Figure 23B] FIG. 23B is a top view of the arrangement of meta units above the color filter layer in FIG. 23A. [Figure 24] 1 is a cross-sectional view of an optical device according to some embodiments of the present disclosure. [Diagram 25] 1 is a cross-sectional view of an optical device according to some embodiments of the present disclosure. [Figure 26] 1 is a cross-sectional view of an optical device according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The following disclosure provides many different embodiments or examples for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first configuration above or on a second configuration in the following description may include embodiments in which the first and second configurations are formed in direct contact, and may include embodiments in which an additional configuration may be formed between the first and second configurations such that the first and second configurations are not in direct contact. Furthermore, the disclosure may repeat reference numbers and / or letters in various examples. This repetition is for the purpose of simplicity and clarity, and does not in itself indicate a relationship between the various embodiments and / or configurations described. It should be understood that the number of any elements and configurations is merely for illustration purposes and is not intended to limit the disclosure.

[0026] In this specification, the terms first, second, etc. are used to describe various elements, but it should be understood that these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element can be referred to as a second element, and similarly, a second element can be referred to as a first element, without departing from the scope of the embodiment. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0027] Additionally, spatially relative terms such as "lower," "below," "bottom," "upper," "top," and the like, are intended to describe the relationship of one element or feature to another element or feature as depicted in the figures and may be used herein for ease of description. The spatially relative terms are intended to encompass different orientations of the device during 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 similarly interpreted.

[0028] FIG. 1 is a cross-sectional view of an optical device 100 according to some embodiments of the present disclosure. The optical device 100 includes a photoelectric conversion layer 110, a buffer layer 120, an underlayer 130, an anti-reflection (ARC) layer 140, and a plurality of meta units 150. The photoelectric conversion layer 110 includes a plurality of photodiodes 112 (including photodiodes 112a, 112b, 112c) and a plurality of deep trench isolations (DTIs) 114 separating each of the photodiodes 112. The photodiodes 112 are configured to detect external light (e.g., light L). The buffer layer 120 is disposed on the photoelectric conversion layer 110. In some embodiments, the buffer layer 120 may include an organic material or an inorganic material. The buffer layer 120 is configured to reduce the reflection of silicon. The underlayer 130 is disposed on the buffer layer 120. In some embodiments, the underlayer 130 may include a material such as a resin, a polyimide, an acrylate, a polyvinyl alcohol, or a photoresist. Antireflective layer 140 is disposed over underlayer 130 and is configured to prevent reflections. In some embodiments, antireflective layer 140 may include organic or inorganic multi-film materials, such as SiO2, SiH, TiO2, Ti3O5, Ta2O5, MgF2, Al2O3, ZrO2, or other suitable materials. In some embodiments, antireflective layer 140 may include a plurality of microstructures, such as moth-eye microstructures.

[0029] As shown in FIG. 1, the metaunits 150 are disposed above the photoelectric conversion layer 110. Specifically, the metaunits 150 are embedded in the underlayer 130 and the anti-reflection layer 140. The metaunits 150 are disposed with a space between each other. The metaunits 150 extend in a first direction D1 and are disposed along a second direction D2 substantially perpendicular to the first direction. A plurality of metaunits 150 form a "metalayer." The metaunits 150 can provide optical functions such as light collection, light branching, scattering, filtering, refraction, and reflection depending on the shape and arrangement of the metaunits 150. The metaunits 150 are used for imaging functions such as focusing, defocusing, or correcting optical aberrations of light L. In some embodiments, the metaunits 150 are 2D transition metal dichalcogenides (2D TMDs) such as ZrO2, TiO2, Si x N y (x and y are positive integers, x ranging from 1 to 3 and y ranging from 1 to 4), ITO, Si, a-Si, p-Si, III-V semiconductor compounds, or combinations thereof.

[0030] See FIG. 1 . The thickness T of the underlayer 130 is defined as the bottom surface 150S of each of the metaunits 150 to the top surface 120S of the buffer layer 120. The thickness T of the underlayer 130 may be determined by the focal length of the light L after the light L passes through the anti-reflection layer 140 and the metaunits 150. The focal length of the light L is related to the design and arrangement of the different metaunits 150. In some embodiments, the thickness of the underlayer 130 may range from 0 nm to 4000 nm, such as 500, 1000, 1300, 1800, 2500, 3000, or 3500 nm. If the thickness T of the underlayer 130 is greater than 4000 nm, the image quality of the optical device 100 may not be affected.

[0031] FIG. 2A is a three-dimensional view of the meta unit 150 in the optical device 100 of FIG. 1. The meta unit 150 includes a top TP and a bottom BP connected to the top TP. Both the top TP and the bottom BP extend in a first direction D1. In some embodiments, the top TP extends continuously along the first direction D1 and directly contacts the bottom BP. The surface area At of the top TP is larger than that of the bottom BP. The material of the top TP is the same as that of the bottom BP. As shown in FIG. 2A, the shape of the meta unit 150 is circular when viewed from the top or bottom direction (in the D2-D3 plane, the direction D3 is substantially perpendicular to the directions D1 and D2). The surface area At of the top TP is larger than that of the bottom BP. The material of the top TP is the same as that of the bottom BP. As shown in FIG. 2A, the shape of metaunit 150 is circular when viewed from the top or bottom direction (in the D2-D3 plane, direction D3 is substantially perpendicular to directions D1 and D2). As shown in FIG. 1, the top TP of each metaunit 150 is embedded in anti-reflective layer 140, and the bottom of each metaunit 150 is embedded in underlayer 130.

[0032] FIG. 2B is a side view of the metaunit 150 of FIG. 2A. The metaunit 150 has a T-shaped structure. In some embodiments, the total height H of the metaunit 150 ranges from 0.05 μm to 5 μm, such as 1, 2.5, 3.5, or 4.5 μm. In some embodiments, the top height ht of the top TP is different from the bottom height hb of the bottom BP. In some embodiments, the top height ht of the top TP is smaller than the bottom height of the bottom BP. In some embodiments, the ratio of the top height ht to the bottom height hb is 1 / 15, 1 / 10, 1 / 5, 1 / 4, or 1 / 2, ranging from 1 / 20 to 1. In some embodiments, when the ratio is smaller than 1 / 5 or 1 / 4, it may not have a positive effect on the image quality of the optical device 100. As shown in FIG. 2B, the shape of each top TP of the metaunit 150 includes a rectangle when viewed from the side, and the shape of each bottom BP of the metaunit 150 includes a rectangle when viewed from the side. In some embodiments, the top width Wt of the top portion TP is greater than the bottom width Wb of the bottom portion BP. In some embodiments, the top width ranges from 40 nm to 850 nm. In some embodiments, the bottom width Wb ranges from 20 nm to 800 nm. It is understood that the size of the metaunit 150 can be adjusted according to the design and requirements of the optical device 100.

[0033] Please refer to FIG. 1 and FIG. 2B. The top TP of the meta unit 150 is embedded in the bottom of the anti-reflection layer 140, and the bottom BP of the meta unit 150 is embedded in the top of the underlayer 130. The surface area At of the top TP is larger than the surface area of ​​the bottom BP, and the projection Pb of the bottom BP onto the photoelectric conversion layer 110 is present in the projection Pt of the top TP onto the photoelectric conversion layer 110, so please refer to FIG. 1 and FIG. 2A. In other words, the projection Pb is smaller than the projection Pt. Each of the meta units 150 shown in FIG. 1 has a projection Pb of the bottom BP onto the photoelectric conversion layer 110 and a projection Pt of the top TP onto the photoelectric conversion layer 110, where it is understood that the projections Pb of different meta units are spaced apart from each other, and the projections Pt of different meta units 150 are spaced apart from each other.

[0034] In some embodiments, the refractive index of the metaunit 150 is greater than that of the underlayer 130, which is greater than that of the anti-reflection layer 140. When light L of different wavelengths is transmitted to the optical device 100, energy resonance occurs in the metaunit 150. Specifically, since the metaunit 150 has a higher refractive index than the anti-reflection layer 140 and the underlayer 130, the light L is tuned by energy resonance in the metaunit 150. More specifically, since the energy resonance occurs in the metaunit 150, the refraction angle of the light L having a long wavelength (e.g., red light) is greater than the refraction angle of the light L having a short wavelength (e.g., blue light). Therefore, the light L is split through the metaunit 150 toward the photoelectric conversion layer 110. In addition, since the metaunit 150 has a T-shaped structure (the size of the top TP of the metaunit 150 is greater than the bottom BP of the metaunit 150), the split result is better than that of a cylindrical metaunit. As a result, the meta unit 150 of the present disclosure can provide better spectral results for the light L, and the image quality of the optical device 100 can be improved.

[0035] In some embodiments, the refractive index of metaunits 150 ranges from 1.4 to 6.5, such as 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, or 6. If the refractive index of metaunits 150 is less than 1.4 or greater than 6.5, the desired optical phenomena described above may not be achieved. If the refractive index of metaunits 150 is less than the refractive index of underlayer 130, the desired optical phenomena described above may not be achieved. When the refractive index of metaunits 150 is less than the refractive index of antireflective layer 140, antireflective layer 140 increases the reflection of light L.

[0036] Please refer to FIG. 1 again. The sizes of the meta units 150 may be different from each other. For example, the size of the meta unit 150 above the photodiode 112b is larger (wider) than the meta unit 150 above the photodiode 112c. The size of the meta unit 150 above the photodiode 112a is larger (wider) than the meta unit 150 above the photodiode 112c. The size of the meta unit 150 above the photodiode 112a, the size of the meta unit 150 above the photodiode 112b, and the size of the meta unit 150 above the DTI 114 are different from each other.

[0037] The space S between the two centerlines of any two adjacent metaunits 150 is the same as shown in FIG. 1. In some embodiments, the space S is smaller than the wavelength of light L. In other embodiments, the space S between the two centerlines of any two metaunits 150 is different. In some embodiments, there may be no metaunit 150 above any one of the photodiodes 112a, 112b, 112c. Different sizes of different metaunits 150 and arrangements of metaunits 150 may cause different optical aberrations, which can be adjusted according to the design and requirements of the optical device 100.

[0038] 3A, 4A, and 5-12 are three-dimensional views of metaunits 150a-150j according to alternative embodiments of the present disclosure. Each of metaunits 150a-150j can be an alternative embodiment of metaunit 150 shown in FIG. 1. In other words, metaunit 150 shown in FIG. 1 can be replaced with any one of metaunits 150a-150j. In some embodiments, the shape of each of the metaunits shown in FIG. 1 (including metaunits 150, 150a-150j) is circular, square, rectangular, or a combination thereof, as viewed from the top direction (D2-D3 plane). Note that the size of each of the top portions TP of any one of metaunits 150a-150j is larger than the size of each of the bottom portions BP of any one of metaunits 150a-150j.

[0039] Please refer to Figures 3A and 3B. Figure 3B is a side view of metaunit 150a of Figure 3A. As shown in Figure 3B, the shape of the top TP of metaunit 150a includes a trapezoid, and a first top width Wt1 of the trapezoid is smaller than a second top width Wt2 of the trapezoid. Specifically, the top TP gradually increases in width from top to bottom. In some embodiments, the base angle θ1 of the trapezoid is 45, 60, or 75 degrees, and ranges from 30 degrees to 90 degrees.

[0040] Please refer to Figures 4A and 4B. Figure 4B is a side view of metaunit 150b of Figure 4A. As shown in Figure 4B, the shape of the top TP of metaunit 150b includes a trapezoid, and the first top width Wt1 of the trapezoid is greater than the second top width Wt2 of the trapezoid. Specifically, the width of the top TP gradually decreases from top to bottom. In some embodiments, the base angle θ2 of the trapezoid is 100, 110, 120, or 130 degrees, and ranges from 90 degrees to 135 degrees. As shown in Figures 3A and 4A, the shape of metaunits 150a, 150b is circular (D2-D3 plane) when viewed from the top or bottom.

[0041] As shown in Figure 5, the top TP and bottom BP of metaunit 150c are both square when viewed from the top or bottom. As shown in Figure 6, the top TP and bottom BP of metaunit 150d are both square when viewed from the top or bottom. Metaunit 150d has a trapezoidal shape when viewed from the side (D1-D2 plane or D1-D3 plane).

[0042] As shown in FIG. 7, the shape of both the top TP and bottom BP of meta unit 150e is rectangular when viewed from the top or bottom. As shown in FIG. 8, the shape of both the top TP and bottom BP of meta unit 150f is rectangular when viewed from the top or bottom. Meta unit 150f has a trapezoidal shape when viewed from the side (D1-D2 plane or D1-D3 plane). In other words, meta unit 150f has a trapezoidal shape when viewed from the side.

[0043] As shown in Figure 9, both the top TP and bottom BP of meta unit 150g have a T-shape when viewed from the top or bottom, and the T-shape of the top TP is larger than the T-shape of the bottom BP. As shown in Figure 10, both the top TP and bottom BP of meta unit 150h have a T-shape when viewed from the top or bottom, and the T-shape of the top TP is larger than the T-shape of the bottom BP. Meta unit 150h has a trapezoidal shape when viewed from the side (D1-D2 plane or D1-D3 plane).

[0044] As shown in Fig. 11, both the top TP and bottom BP of metaunit 150i have a cross shape when viewed from the top or bottom, and the cross shape of the top TP is larger than the cross shape of the bottom BP. As shown in Fig. 12, both the top TP and bottom BP of metaunit 150j have a cross shape when viewed from the top or bottom. Metaunit 150j has a trapezoid shape when viewed from the side (D1-D2 plane or D1-D3 plane).

[0045] 13 is a cross-sectional view of an array of metaunits 150 according to an alternative embodiment of the present disclosure. The sizes of the metaunits 150 are the same as each other, and the metaunits 150 are spaced apart from each other. Similarly, the tops TP of the metaunits 150 are embedded in the bottom of the anti-reflective layer 140, and the bottoms BP of the metaunits 150 are embedded in the top of the underlayer 130.

[0046] 14 and 15 are cross-sectional views of an array of metaunits 150 according to an alternative embodiment of the present disclosure. The tops TP (see FIG. 1) of various metaunits are bonded together to form one continuous top 151, and the bottoms BP of various metaunits protrude from the continuous top 151, so that the metaunits 150 have a comb shape. Specifically, the continuous top 151 is disposed between the underlayer 130 and the anti-reflective layer 140. The sizes of the bottoms of the metaunits 150 are the same as each other, as shown in FIG. 14. The sizes of the bottoms BP of the metaunits 150 are different from each other, as shown in FIG. 15.

[0047] 16 and 17 are cross-sectional views of an array of metaunits 150 according to an alternative embodiment of the present disclosure. As shown in FIG. 16, the metaunits are arranged in two layers (a first layer L1 and a second layer L2), with the second layer being completely embedded in the underlayer 130. As shown in FIG. 17, the metaunits are arranged in three layers (a first layer L1, a second layer L2, and a third layer L3), with the third layer being completely embedded in the underlayer 130.

[0048] 18-21 are top views of an array of metaunits 150 according to alternative embodiments of the present disclosure. The metaunits 150 may be arranged to form a matrix array, as shown in FIG. 18. The metaunits 150 may be arranged to form a polygonal array, such as a hexagonal array, as shown in FIG. 19. The metaunits 150 may be arranged to form concentric circles, as shown in FIG. 20. The metaunits 150 may be arranged randomly, as shown in FIG. 18. The arrangement of the metaunits 150 can be adjusted according to the design and requirements of the optical device.

[0049] FIG. 22 is a cross-sectional view of an optical device 100A according to some embodiments of the present disclosure. The difference between the optical device 100A of FIG. 22 and the optical device 100 of FIG. 1 is the color filter layer 160. Here, the same features are labeled with the same numerical references, and the description of the same features is not repeated. The meta unit 150 includes meta units 150-1, 150-2, 150-3, 150-4, 150-5, 150-6, and 150-7. The color filter layer 160 is disposed between the photoelectric conversion layer 110 and the underlayer 130. The color filter layer 160 is disposed on the buffer layer 120. The color filter layer 160 includes a plurality of gratings 161 and a plurality of color filters 162a, 162b, and 162c. The grating 161 separates the color filters 162a, 162b, and 162c.

[0050] Further, please refer to FIG. 22. Meta unit 150-2 corresponds to color filter 162a and photodiode 112a, meta unit 150-4 corresponds to color filter 162b and photodiode 112b, and meta unit 150-6 corresponds to color filter 162c and photodiode 112c. Meta units 150-1, 150-3, 150-5, and 150-7 correspond to grid 161 and DTIs 114. Therefore, the projection of meta unit 150 (including meta units 150-1 to 150-7) onto photoelectric conversion layer 110 partially overlaps with the projection of grid 161 onto photoelectric conversion layer 110. Specifically, the projection of meta units 150-1, 150-3, 150-5, and 150-7 onto photoelectric conversion layer 110 overlaps with the projection of grid 161 onto photoelectric conversion layer 110. Color filter layer 160 may be arranged in an array and may include RGB filters, RGBW filters, RGBC filters, RYYB filters, CMY filters, or other combination filters. For example, color filter 162a may be a red filter, color filter 162b may be a green filter, and color filter 162c may be a blue filter.

[0051] FIG. 23A is a top view of a color filter layer 160a according to some embodiments of the present disclosure. The color filter layer 160a is an array of RGBW filters. FIG. 23B is a top view of a meta unit 150 above the color filter layer 160a of FIG. 23A, with some elements not shown for clarity. As shown in FIG. 23A and FIG. 23B, the meta units 150 are only disposed above the RGB filters, and there is no meta unit 150 disposed above the W filter. In each of the R, G, and B filters, the meta units 150 are randomly disposed.

[0052] 24 is a cross-sectional view of an optical device 100B according to some embodiments of the present disclosure. The difference between the optical device 100B in FIG. 24 and the optical device 100A in FIG. 22 is the thickness of the underlayer 130. Specifically, the bottom surface 150S of each of the meta units 150 contacts the top surface 160S of the color filter layer 160.

[0053] FIG 25 is a cross-sectional view of an optical device 100C according to some embodiments of the present disclosure. The difference between the optical device 100C of FIG 25 and the optical device 100A of FIG 22 is the position of the meta units 150 and the number of meta units 150. Specifically, meta units 150-2, 150-4, and 150-6 are embedded in the color filter layer 160. More specifically, meta unit 150-2 is embedded in color filter 162a, meta unit 150-4 is embedded in color filter 162b, and meta unit 150-6 is embedded in color filter 162c. Meta units 150 (meta units 150-2, 150-4, 150-6) are spaced apart from lattice 161, and the projection of meta units 150 (meta units 150-2, 150-4, 150-6) onto photoelectric conversion layer 110 is spaced apart from the projection of lattice 161 onto photoelectric conversion layer 110.

[0054] FIG. 26 is a cross-sectional view of an optical device 100D according to some embodiments of the present disclosure. The difference between the optical device 100D of FIG. 26 and the optical device 100C of FIG. 25 is the number of gratings 161 and meta units 150. Specifically, the gratings 161 of the color filter layer 160 in the optical device 100C are replaced by meta units 150-1, 150-3, 150-5, and 150-7. Meta unit 150-2 remains in color filter 162a, meta unit 150-4 remains in color filter 162b, and meta unit 150-6 remains in color filter 162c. Meta unit 150-3 is disposed at the boundary between color filters 162a and 162b, and meta unit 150-5 is disposed at the boundary between color filters 162b and 162c.

[0055] The disclosed optical device has a plurality of meta units embedded therein, each of the meta units having a top and a bottom, the top having a larger surface area than the bottom, and the disclosed meta units can provide better optical aberration correction, improving the image quality of the optical device.

[0056] The present disclosure is as above, but the present disclosure is not used to limit the present disclosure. Those skilled in the art can make various changes, substitutions and modifications in this specification without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure is subject to the claims attached hereto and their equivalent configurations.

Claims

1. Photoelectric conversion layer, an underlayer disposed on the photoelectric conversion layer; an antireflective layer disposed on the underlayer; and a plurality of meta units arranged above the photoelectric conversion layer, each of the plurality of meta units including a top and a bottom, the projection of the bottom onto the photoelectric conversion layer being within a range of the projection of the top onto the photoelectric conversion layer; Including, an optical device comprising: a refractive index of the plurality of metaunits greater than a refractive index of the underlayer; and the refractive index of the underlayer greater than a refractive index of the anti-reflective layer.

2. 2. The optical device of claim 1, wherein the top of each of the plurality of meta-units is embedded in the anti-reflection layer and the bottom of each of the plurality of meta-units is embedded in the underlayer.

3. 2. The optical device of claim 1, wherein the shape of the top of each of the plurality of metaunits comprises a rectangle when viewed from the side, the shape of the bottom of each of the plurality of metaunits comprises a rectangle when viewed from the side, and a top width of the top is greater than a bottom width of the bottom.

4. 2. The optical device of claim 1, wherein the projections of the respective meta-units onto the photoelectric conversion layer are spaced apart from one another.

5. 2. The optical device of claim 1, wherein the tops of the plurality of meta-units are joined to form a continuous top.

6. 2. The optical device of claim 1, wherein a top height of the top of each of the plurality of metaunits is less than a bottom height of the bottom of each of the plurality of metaunits.

7. The optical device of claim 1, characterized in that the shape of each of the multiple meta units is circular, square, or rectangular when viewed from above, and the shape of the upper part of each of the multiple meta units is rectangular or trapezoidal when viewed from the side.

8. The optical device of claim 1 , wherein the shape of each of the plurality of meta units is T-shaped or cross-shaped when viewed from above, and the upper portion of each of the plurality of meta units is trapezoidal when viewed from the side.

9. The optical device of claim 1, characterized in that the shape of the upper part of each of the multiple meta units includes a trapezoid when viewed from the side, the top width of the trapezoid is smaller than the bottom width of the trapezoid, and the base angle of the trapezoid is in the range of 30 to 90 degrees.

10. The optical device of claim 1, characterized in that the shape of the upper part of each of the multiple meta units, when viewed from the side, includes a trapezoid, the top width of the trapezoid is greater than the bottom width of the trapezoid, and the base angle of the trapezoid is in the range of 90 to 135 degrees.

11. the photoelectric conversion layer includes a first photodiode, a second photodiode, and a deep trench isolation disposed between the first photodiode and the second photodiode; the meta units include a first meta unit disposed above the first photodiode, a second meta unit disposed above the second photodiode, and a third meta unit disposed above the deep trench isolation; the size of the first metaunit, the size of the second metaunit, and the size of the third metaunit are different from one another; 2. The optical device of claim 1, wherein the refractive index of the metaunits is in the range of 1.4 to 6.

5.

12. The meta unit is a two-dimensional transition metal dichalcogenide, ZrO ２ , TiO ２ , Si ｘ N ｙ , ITO, Si, a-Si, p-Si, III-V semiconductor compounds, or combinations thereof, wherein x and y are positive integers, x in the range of 1 to 3, and y in the range of 1 to 4.

13. 2. The optical device of claim 1, wherein the metaunits are arranged in two or three layers, with the lowest layer of metaunits being completely embedded in the underlayer.

14. Further, the color filter layer is disposed between the photoelectric conversion layer and the underlayer, The optical device of claim 1 , wherein a bottom surface of each of the plurality of meta units contacts an upper surface of the color filter layer.

15. Further, a color filter layer is disposed between the photoelectric conversion layer and the underlayer, 2. The optical device of claim 1 , wherein the color filter layer includes a plurality of gratings and a plurality of color filters, and the projection of the plurality of meta units onto the photoelectric conversion layer partially overlaps with the projection of the plurality of gratings onto the photoelectric conversion layer.

16. Further, a color filter layer is disposed between the photoelectric conversion layer and the underlayer, 2. The optical device of claim 1, wherein the plurality of meta units are embedded in the color filter layer.

17. Further, a color filter layer is disposed between the photoelectric conversion layer and the underlayer, the color filter layer includes a plurality of gratings and a plurality of color filters; 2. The optical device of claim 1, wherein the projections of the plurality of metaunits onto the photovoltaic layer are spaced apart from the projections of the plurality of gratings onto the photovoltaic layer.

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