Image sensor including beam splitter

Abstract

An image sensor includes a plurality of photodiodes arranged at a semiconductor substrate and a beam splitter arranged on the photodiodes. The beam splitter splits incident light according to wavelengths so that split lights of different colors enter different photodiodes respectively. The beam splitter includes a first pattern structure having a cross-sectional structure in which a plurality of refractive layer patterns are arranged in a lateral direction.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2017-0154312 filed on November 17, 2017 in the Korean Intellectual Property Office (KIPO), the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] Example embodiments relate to image sensors. More particularly, example embodiments relate to image sensors including a beam splitter. Background Art

[0004] Recently, image sensors having small pixel sizes and excellent characteristics have been developed.

[0005] These image sensors are expected to have high sensitivity by reducing the amount of absorbed light that does not reach the photodiode. Summary of the invention

[0006] Example embodiments provide an image sensor having high sensitivity.

[0007] According to an example embodiment, an image sensor is provided. The image sensor includes a plurality of photodiodes arranged on a semiconductor substrate and a beam splitter arranged on the photodiodes. The beam splitter splits incident light according to wavelengths so that split lights of different colors enter different photodiodes respectively. The beam splitter includes a first pattern structure having a cross-sectional structure in which a plurality of refractive layer patterns are arranged adjacent to each other in a lateral direction.

[0008] According to an example embodiment, an image sensor is provided. The image sensor includes: a plurality of photodiodes, which are respectively arranged in unit pixel regions of a semiconductor substrate; and a beam splitter, which is arranged on a first surface of the semiconductor substrate and is spaced apart from the photodiodes. The beam splitter splits incident light according to wavelengths so that split lights of different colors enter different photodiodes, respectively. The beam splitter includes a first pattern structure that forms a boundary extending in a vertical direction between two of the plurality of refractive layer patterns.

[0009] According to an example embodiment, an image sensor is provided. The image sensor includes: a plurality of photodiodes, which are respectively arranged in unit pixel regions of a semiconductor substrate; and a beam splitter, which is arranged on a first surface of the semiconductor substrate and is spaced apart from the photodiodes. The beam splitter splits incident light according to wavelengths so that split lights of different colors enter different photodiodes, respectively. The beam splitter includes a first refraction pattern structure having a cross-sectional structure in which a plurality of refraction layer patterns are stacked in a lateral direction relative to each other.

[0010] According to example embodiments, the image sensor includes a beam splitter. Therefore, the amount of light entering the photodiode may be increased, so that the image sensor may have high sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic cross-sectional view illustrating an image sensor according to example embodiments;

[0012] Figure 2 is a plan view showing an arrangement of a beam splitter according to an example embodiment;

[0013] Figure 3 is a schematic cross-sectional view illustrating an image sensor according to example embodiments;

[0014] Figures 4 to 15 are cross-sectional views and plan views for explaining a method of forming a beam splitter included in an image sensor according to example embodiments;

[0015] Fig.16 is a cross-sectional view illustrating a beam splitter included in an image sensor according to example embodiments;

[0016] Fig.17 is a cross-sectional view illustrating a beam splitter included in an image sensor according to example embodiments;

[0017] Fig.18 and Fig.19 is a cross-sectional view illustrating a method for forming a beam splitter included in an image sensor according to example embodiments;

[0018] Fig. 20 is a cross-sectional view illustrating a beam splitter included in an image sensor according to example embodiments;

[0019] Fig.21 is a cross-sectional view illustrating an image sensor according to example embodiments;

[0020] Fig. 22 is a cross-sectional view illustrating an image sensor according to example embodiments;

[0021] Fig.23 is a cross-sectional view illustrating an image sensor according to example embodiments;

[0022] Fig.24 is a cross-sectional view illustrating an image sensor according to example embodiments. DETAILED DESCRIPTION

[0023] Hereinafter, example embodiments will be described more fully with reference to the accompanying drawings.

[0024] Figure 1 is a schematic cross-sectional view illustrating an image sensor according to example embodiments. Figure 2 is a plan view illustrating an arrangement of a beam splitter according to example embodiments.

[0025] Reference Figure 1 , the image sensor may include a plurality of unit pixels arranged in a matrix configuration. Each of the unit pixels may include photodiodes 10a, 10b, and 10c and color filters 14a, 14b, and 14c. A beam splitter 18 may be arranged on the color filters 14a, 14b, and 14c.

[0026] The photodiodes 10a, 10b and 10c may be arranged in a semiconductor substrate. The semiconductor substrate may be selected from a bulk substrate, an epitaxial substrate or a SOI (silicon on insulator) substrate. For example, the semiconductor substrate may include silicon (Si). In addition, the semiconductor substrate may include a semiconductor element such as germanium (Ge) or a compound semiconductor such as silicon carbide (SiC), gallium arsenide (GaAs), indium arsenide (InAs) or indium phosphide (InP). The photodiodes 10a, 10b and 10c may include an impurity region doped with impurities.

[0027] The first interlayer insulating layer 12 may be arranged to cover the photodiodes 10a, 10b, and 10c on the semiconductor substrate. For example, the first interlayer insulating layer 12 may include an electrically insulating material such as silicon oxide.

[0028] Color filters 14a, 14b, and 14c may be disposed on the first interlayer insulating layer 12. The color filters 14a, 14b, and 14c may selectively transmit colored light having a specific wavelength.

[0029] The color filter may include a red filter 14a, a green filter 14b, and a blue filter 14c. Other color filters may be used, and the color filters may be generally referred to as a first color filter, a second color filter, a third color filter, etc., wherein each color filter filters a different color. The color filters 14a, 14b, and 14c may be arranged to face the photodiodes 10a, 10b, and 10c, respectively, and to be spaced apart from the photodiodes 10a, 10b, and 10c, respectively. For example, the red filter 14a may be vertically aligned and facing the first photodiode 10a, the green filter 14b may be vertically aligned and facing the second photodiode 10b, and the blue filter 14c may be vertically aligned and facing the third photodiode 10c.

[0030] The planarization layer 16 may be disposed on the color filters 14a, 14b, and 14c. For example, the planarization layer 16 may include silicon oxide. For example, the planarization layer 16 may include a SOG (Silicon On Glass) layer.

[0031] The beam splitter splits the incident light from the outside according to the wavelength of the light before it reaches the color filters 14a, 14b and 14c, so that the split lights of different colors can enter different color filters 14a, 14b and 14c. Therefore, the beam splitter 18 can be arranged on the color filters 14a, 14b and 14c, and can be spaced apart from the color filters 14a, 14b and 14c. Through the beam splitter 18, red light can enter the red filter 14a, green light can enter the green filter 14b, and blue light can enter the blue filter 14c. The split lights with different colors can generally be referred to as the first colored light, the second colored light and the third colored light emitted from the beam splitter 18 after being split. Figure 1 As can be seen in the example of , the beam splitter includes a first refraction pattern structure (eg, 18) having a cross-sectional structure in which a plurality of refraction layer patterns (eg, 18b, 18a, 18b, 18a, and 18b) are stacked in a lateral direction relative to each other.

[0032] The filling layer pattern 20 may be arranged on both sides of the beam splitter 18. For example, the filling layer pattern 20 may include silicon oxide. The upper surface of the beam splitter 18 and the upper surface of the filling layer pattern 20 may be arranged on the same plane to be continuously connected to each other. It should be noted that terms such as "same", "equal", "planar" or "coplanar" used herein when referring to orientation, layout, position, shape, size, amount or other measurement do not necessarily mean exactly the same orientation, layout, position, shape, size, amount or other measurement, but are intended to cover almost the same orientation, layout, position, shape, size, amount or other measurement within an allowable range of variation that may be caused, for example, by a manufacturing process. Unless the context or other expressions clearly indicate otherwise, the terms "substantially" or "substantially" may be used herein to emphasize this meaning. For example, items described as "substantially the same", "substantially equal" or "substantially planar" may be exactly the same, equal or planar, or may be the same, equal or planar within an allowable range of variation that may be caused, for example, by a manufacturing process.

[0033] The cross section of the pattern structure provided as the beam splitter 18 may have a shape in which a plurality of refractive layer patterns 18a and 18b are repeatedly arranged (e.g., stacked) in the lateral direction. For example, the vertical height (e.g., vertical relative to the surface of the substrate) of some or all of these patterns 18a and 18b may be greater than the horizontal width (e.g., horizontal relative to the surface of the substrate). Therefore, the refractive layer patterns 18a and 18b may be divided by a boundary extending in the vertical direction. In an example embodiment, the pattern structure 18 may have a vertical height in the vertical direction relative to the surface of the substrate. to In example embodiments, the pattern structure 18 may have a height of to The width of the pattern structure 18 is 1.5mm. Therefore, in some embodiments, the height of the pattern structure 18 may be about the same as the width of the pattern structure 18. In other embodiments, the height of the pattern structure 18 may be between about 1 times and about 4 times the width of the pattern structure 18. In more specific examples, the height of the pattern structure 18 may be between about 2 times and about 3 times the width of the pattern structure 18. Therefore, in these different examples, the width of the combined multiple refractive layer patterns forming the pattern structure 18 in the horizontal direction is less than the height of the combined multiple refractive layer patterns in the vertical direction. As described below, the features of the pattern structure 18 in each figure are not necessarily drawn to scale. The width and number of the refractive layer patterns 18a and 18b may be adjusted so that the pattern structure 18 may have a predetermined width. In the pattern structure 18, the refractive layer patterns may be arranged symmetrically relative to the centrally arranged refractive layer pattern 18b. Terms such as "about" or "approximately" may reflect the amount, size, orientation or layout that is changed only in a small relative manner and / or in a manner that does not significantly change the operation, function or structure of a particular element. For example, a range of "about 0.1 to about 1" may include ranges of deviations around 0.1, such as 0%-5%, and deviations around 1, such as 0%-5%, especially if such deviations maintain the same effect as the listed range.

[0034] As shown in the figure, in some embodiments, the first refraction layer pattern 18b arranged in the center may have a larger width than each of the second refraction layer patterns 18a arranged laterally oppositely, and may have a larger width than each of the third refraction layer patterns 18b arranged laterally oppositely on the outside. In some embodiments, each third refraction layer pattern 18b arranged laterally on the outside has a larger width than each second refraction layer pattern 18a arranged laterally, but in other embodiments, these widths may be the same. It should be understood that although the terms first, second, third, etc. can be used herein to describe each element, component, area, layer and / or part, these elements, components, areas, layers and / or parts should not be limited by these terms. Unless otherwise indicated by the context, for example as a naming convention, these terms are only used to distinguish one element, component, area, layer or part from another element, component, area, layer or part. Therefore, the first element, component, area, layer or part discussed below in a part of the specification may be referred to as a second element, component, area, layer or part in another part of the specification or in the claims without departing from the teachings of the present invention. In addition, in certain cases, even if “first”, “second”, etc. are not used to describe a certain term in the specification, it can be referred to as “first…” or “second…” in the claims to distinguish different claimed elements from each other.

[0035] The refraction layer patterns 18a and 18b may include a transparent material having a refractive index in the range of, for example, 2.0 to 3.0. Examples of the transparent material may include metal oxides such as titanium oxide, niobium oxide, and the like.

[0036] Since the refraction layer patterns 18 a and 18 b are arranged in the lateral direction, a grain boundary extending in the vertical direction may be formed at an interface between the refraction layer patterns 18 a and 18 b.

[0037] In example embodiments, the refractive layer patterns 18a and 18b adjacent to each other may include the same transparent material. In some embodiments, the refractive layer patterns 18a and 18b adjacent to each other may include different transparent materials. For example, two refractive layer patterns 18a and 18b that are different from each other (and formed of the same or different materials) may be alternately arranged in the transverse direction. Therefore, the refractive layer patterns 18a and 18b may be divided by a boundary extending in the vertical direction. The boundary may include a grain boundary extending in the vertical direction.

[0038] In example embodiments, the refraction layer patterns 18a and 18b adjacent to each other may have different widths. For example, some of the refraction layer patterns 18a and 18b may have the same width (e.g., each of the third refraction layer patterns 18b arranged laterally on the outside may have the same width, and each of the second refraction layer patterns 18a arranged laterally may have the same width, and in some cases, all of the refraction layer patterns arranged laterally have the same width as each other) and some of the refraction layer patterns 18a and 18b may have different widths from each other (e.g., the middle refraction layer pattern 18b may be wider than any other refraction layer pattern). In other embodiments, each of the refraction layer patterns 18a and 18b adjacent to each other may have the same width.

[0039] like Figure 2 As shown, the beam splitter 18 may face at least a portion of each color filter 14a, 14b, and 14c in a vertical direction. In a plan view, the beam splitter 18 may have a grid shape. In an example embodiment, the beam splitter 18 may have a shape extending to cross the green filter 14b.

[0040] A capping layer 22 may be disposed on the beam splitter 18 and the filling layer pattern 20. For example, the capping layer 22 may include silicon oxide.

[0041] A microlens 24 may be disposed on the capping layer 22. The microlens 24 may have a curved upper surface. In example embodiments, the microlens 24 may be omitted.

[0042] As explained above, the beam splitter 18 splits the light according to the wavelength of the incident light from the outside to allow the split lights of different colors to enter the different color filters 14a, 14b and 14c. Therefore, the light having a wavelength capable of passing through the color filters 14a, 14b and 14c can be incident on the corresponding color filters 14a, 14b and 14c. Therefore, the amount of light absorbed by the color filters 14a, 14b and 14c can be reduced, thereby increasing the amount of light incident on the photodiodes 10a, 10b and 10c. In addition, the materials or widths of the respective refractive layer patterns 18a and 18b arranged in the lateral direction can be adjusted or combined according to a known rule for splitting light, so that the beam splitter 18 can have a desired splitting feature.

[0043] Figure 3 is a schematic cross-sectional view illustrating an image sensor according to example embodiments.

[0044] Figure 3 The image sensor shown is Figure 1 The image sensors shown are substantially the same except that color filters and planarization layers are not included in the unit pixels.

[0045] Reference Figure 3 , the photodiodes 10a, 10b, and 10c may be arranged in the semiconductor substrate. The first interlayer insulating layer 12 may be arranged to cover the photodiodes 10a, 10b, and 10c on the semiconductor substrate.

[0046] A beam splitter 18 may be disposed on the first interlayer insulating layer 12 .

[0047] The beam splitter 18 splits the light according to the wavelength of the incident light from the outside to allow the split lights of different colors to enter different photodiodes 10a, 10b and 10c, respectively. In an exemplary embodiment, the beam splitter 18 may be used as a color filter. For example, through the beam splitter 18, red light may enter the first photodiode 10a, green light may enter the second photodiode 10b, and blue light may enter the third photodiode 10c.

[0048] The beam splitter 18 may have a Figure 1 The construction explained is basically the same construction.

[0049] A filling layer pattern 20 may be disposed on both sides of the beam splitter 18. A capping layer 22 may be disposed on the beam splitter 18 and the filling layer pattern 20. A microlens 24 may be disposed on the capping layer 22. In some embodiments, the microlens 24 may be omitted.

[0050] As described above, the beam splitter 18 splits the light according to the wavelength of the incident light from the outside so that the split lights of different colors can enter different photodiodes 10a, 10b and 10c without passing through separate color filters, thereby simplifying the arrangement structure of the image sensor.

[0051] Hereinafter, an example method of forming a beam splitter included in an image sensor will be described.

[0052] Figures 4 to 15 are cross-sectional views and plan views for explaining a method of forming a beam splitter included in an image sensor according to example embodiments.

[0053] Even though not shown, a photodiode may be formed in the semiconductor substrate. A color filter may be formed on the photodiode. A lower layer 15 may be formed to cover the color filter. In some embodiments, the color filter may be omitted.

[0054] Reference Figure 4 and Figure 5 , a mask pattern 30 is formed on the lower layer 15. The lower layer 15 may be a planarization layer or an interlayer insulating layer. The mask pattern 30 may include a photoresist pattern formed by a photolithography process.

[0055] The mask pattern 30 may be formed on a region where a beam splitter is to be formed. In example embodiments, the mask pattern 30 may have a grid shape in a plan view. For example, the mask pattern 30 may have a shape extending to cross a first color filter (such as a green filter) disposed below the mask pattern 30 in a diagonal direction.

[0056] The mask pattern 30 may have a first line width d1 that is smaller than a target line width of a beam splitter to be formed. In example embodiments, the first line width d1 may be equal to or smaller than half the target line width of the beam splitter. For example, the first line width d1 may be about 1 / 3 of the target line width of the beam splitter. The mask pattern 30 may be formed to have a height greater than a target height of the beam splitter to be formed.

[0057] Reference Figure 6 The first refraction layer 32 is conformally formed on the surface of the mask pattern 30 and the surface of the lower layer 15. For example, the first refraction layer 32 may be formed by atomic layer deposition (ALD). The first refraction layer 32 may be formed to have a first thickness d2.

[0058] The first refractive layer 32 may include a transparent material having a refractive index in the range of, for example, 2.0 to 3.0. Examples of the transparent material may include metal oxides such as titanium oxide, niobium oxide, and the like.

[0059] Reference Figure 7 and Figure 8, the first refraction layer 32 is anisotropically etched to form a first refraction layer pattern 18a on a sidewall of the mask pattern 30. The first refraction layer pattern 18a may have a second line width d2 that is substantially the same as the first thickness.

[0060] In a plan view, the first refraction layer pattern 18a and the mask pattern 30 may have a mesh shape.

[0061] Reference Fig. 9 and Fig.10 , the mask pattern 30 is removed to form a groove 34. The groove 34 may have a mesh shape. The process for removing the mask pattern 30 may include an ashing stripping process. In addition, the first refraction layer pattern 18a may be arranged on both sides of the groove 34.

[0062] Reference Fig.11 The second refractive layer 36 is formed to fill the grooves 34 between the first refractive layer patterns 18a and conformally on the sidewalls of the first refractive layer patterns 18a and the surface of the lower layer 15. For example, the second refractive layer 36 may be formed by atomic layer deposition (ALD). For example, the second refractive layer 36 may be formed on the outer sidewalls of each first refractive layer in the horizontal direction to have a second thickness d3.

[0063] The second refractive layer 36 may include a transparent material having a refractive index in the range of, for example, 2.0 to 3.0. Examples of the transparent material may include metal oxides such as titanium oxide, niobium oxide, etc. The second refractive layer 36 may include a material that is the same as or different from that of the first refractive layer pattern 18a. In certain embodiments, the second thickness d3 may be the same as or greater than the first thickness d2.

[0064] Reference Fig.12 , the second refraction layer 36 is anisotropically etched to form a second refraction layer pattern 18b in the groove 34 and on the sidewall of the first refraction layer pattern 18a. As a result, an initial pattern structure 38 in which the second refraction layer pattern 18b and the first refraction layer pattern 18a are alternately arranged in a lateral direction may be formed. A boundary between the second refraction layer pattern 18b and the first refraction layer pattern 18a may extend in a vertical direction.

[0065] The second refraction layer pattern 18b in the groove 34 may have a first line width d1. The second refraction layer pattern 18b disposed at the outermost side in the preliminary pattern structure 38 may have a third line width d3 substantially the same as the second thickness.

[0066] The initial pattern structure 38 may be set as an initial beam splitter. The height of the initial pattern structure 38 may be determined by the height of the mask pattern 30 previously formed. The height of the initial pattern structure 38 may be substantially the same as or less than the height of the mask pattern 30. In an example embodiment, the line width of the initial pattern structure 38 is the sum of the first line width d1, twice the second line width d2, and twice the third line width d3. The line width of the initial pattern structure 38 may be substantially the same as the target line width of the beam splitter. The first line width to the third line width d1, d2, and d3 may be adjusted according to the target line width of the beam splitter.

[0067] In a specific embodiment, the first line width d1 is greater than each of the second line width d2 and the third line width d3 and may be about 1 / 3 of the line width of the initial pattern structure. In an embodiment, each of the second line width d2 and the third line width d3 may be about 1 / 6 of the line width of the initial pattern structure.

[0068] In some embodiments, an arrangement of an additional refractive layer and an anisotropic etching process may be further performed on the preliminary pattern structure 38 to further form a refractive layer pattern on the sidewall of the preliminary pattern structure 38 .

[0069] In example embodiments, the height of the initial pattern structure 38 may be and In an exemplary embodiment, the width of the initial pattern structure 38 may be between and between.

[0070] When the initial pattern structure 38 is formed by the above process, the arrangement thickness (in the horizontal direction) of each refractive layer may be less than to and may be smaller than the target height of the initial pattern structure 38 (the target height is the final height of the initial pattern structure 38 after planarization, as shown in FIG. Fig.14For example, to form the initial pattern structure 38, the sum of the arrangement thicknesses of the combined first refractive layer 32 and the second refractive layer 36 (e.g., in the horizontal direction) may be about 1 / 2 to about 1 / 3 of the target height of the initial pattern structure 38. For example, each refractive pattern 18b or 18a at a mid-height position of the initial pattern structure 38 may have a thickness less than 1 / 6 of the target height of the initial pattern structure 38. In some embodiments, the thickness of each of the conformally formed refractive layers 32 and 36 measured vertically relative to the surface on which they are formed is between about 1 / 12 to about 1 / 18 of the target height of the initial pattern structure 38. Therefore, since the thicknesses of the first refractive layer 32 and the second refractive layer 36 used to form the initial pattern structure 38 are reduced, the time used to form the initial pattern structure 38 can be reduced. In addition, defects that may be generated in the process of forming the initial pattern structure 38 for a long time can be reduced.

[0071] Reference Fig.13 A filling layer 40 may be formed to cover the initial pattern structure 38. For example, the filling layer 40 may include silicon oxide. For example, the filling layer 40 may include an SOG layer.

[0072] Reference Fig.14 and Fig.15 , the upper surfaces of the initial pattern structure 38 and the filling layer 40 are planarized, so that the upper surface of the initial pattern structure 38 can be made flat. Therefore, the pattern structure 18 and the filling layer pattern 40a are formed. The pattern structure 18 can be set as a beam splitter. For example, the planarization process may include a chemical mechanical polishing process or an etch-back process. When the planarization process is performed, the upper portion of the initial pattern structure 38 can be partially removed. Therefore, the height of the pattern structure 18 can be reduced compared to the height of the initial pattern structure 38, resulting in the horizontal width of the pattern structure 18 (also referred to as the refraction pattern structure) being between about 1 / 2 and about 1 / 3 of the height of the pattern structure 18. The pattern structure 18 can be set as a beam splitter included in a pixel of an image sensor.

[0073] The pattern structure 18 may include a plurality of refractive layer patterns arranged in a transverse direction, which are symmetrically arranged on both sides of the centrally arranged refractive layer pattern 18b. Each independent refractive layer pattern arranged on one side of the centrally arranged refractive layer pattern 18b may have an aspect ratio of, for example, between 18:1 and 12:1. It should be noted that Figures 1 to 15 The aspect ratios of the pattern structure 18 and the refractive patterns 18a and 18b are not drawn to scale, but rather certain dimensions of the features are exaggerated for the sake of clarity.

[0074] The beam splitter 18 formed through the above process may have a desired splitting characteristic by adjusting the material or width of the refractive layer patterns arranged in the lateral direction.

[0075] Hereinafter, example embodiments of a beam splitter having a different structure from the previously explained pattern structure and a method of forming the beam splitter will be described.

[0076] Fig.16 is a cross-sectional view illustrating a beam splitter included in an image sensor according to example embodiments.

[0077] Reference Fig.16 , the beam splitter 58 may have a structure in which the first pattern structure 50 and the second pattern structure 54 are arranged.

[0078] In an exemplary embodiment, it is possible to arrange to The pattern structures 50 and 54 are formed to have a height of to The beam splitter 58 is provided.

[0079] The first pattern structure 50 may have a shape in which a plurality of refraction layer patterns 50a and 50b are arranged in a transverse direction. Therefore, the refraction layer patterns 50a and 50b may form a boundary extending in a vertical direction.

[0080] For example, the first pattern structure 50 may have a structure in which the first refraction layer patterns 50a and the second refraction layer patterns 50b are alternately arranged in the transverse direction. The first pattern structure 50 may have the same structure as previously described with reference to FIG. Figure 1 The pattern structure explained is basically the same structure.

[0081] The first filling layer pattern 52 may be arranged on both sides of the first pattern structure 50. For example, the first filling layer pattern 52 may include silicon oxide. The upper surface of the first pattern structure 50 and the upper surface of the first filling layer pattern 52 may be arranged on the same plane to be continuously connected to each other.

[0082] The second pattern structure 54 may be arranged on the first pattern structure 50. In example embodiments, the second pattern structure 54 may have substantially the same structure as the first pattern structure 50. For example, the width and material of each of the refractive layer patterns 54a and 54b included in the second pattern structure 54 may be substantially the same as the width and material of each of the refractive layer patterns 50a and 50b included in the first pattern structure 50.

[0083] In some embodiments, the width and / or material of each of the refraction layer patterns 54 a and 54 b included in the second pattern structure 54 may be different from the width and / or material of each of the refraction layer patterns 50 a and 50 b included in the first pattern structure 50 .

[0084] In example embodiments, a height of the second pattern structure 54 may be substantially the same as or different from a height of the first pattern structure 50 .

[0085] The incident angle and amount of light entering each pixel may be different depending on the position of the pixel in the image sensor mounted on the chip. Therefore, the position of the second pattern structure 54 arranged on the first pattern structure 50 may be adjusted according to the position of the pixel so that the light entering the pixel can be divided to reach the correct position. Therefore, according to the position of the pixel, the second pattern structure 54 may be correctly aligned with the upper surface of the first pattern structure 50, so that the side boundary of the second pattern structure 54 may be consistent with the side boundary of the first pattern structure 50, or may be shifted relative to the upper surface of the first pattern structure 50.

[0086] In example embodiments, the first pattern structure 50 and the second pattern structure 54 may be correctly aligned with each other on a pixel arranged in a middle portion of the image sensor such that a lower surface of the second pattern structure 54 may coincide with an upper surface of the first pattern structure 50. In addition, the first pattern structure 50 and the second pattern structure 54 may be arranged to be shifted relative to each other such that a portion of a lower surface of the second pattern structure 54 may overlap with an upper surface of the first pattern structure 50, and a portion of a lower surface of the second pattern structure 54 may be suspended on an upper surface of the first pattern structure 50.

[0087] The second filling layer pattern 56 may be arranged on both sides of the second pattern structure 54. The second filling layer pattern 56 may include silicon oxide. The upper surface of the second pattern structure 54 and the upper surface of the second filling layer pattern 56 may be arranged on the same plane to be continuously connected to each other.

[0088] To form beam splitter 58, the same method as previously described with reference to Figures 4 to 15 The first pattern structure 50 and the first filling layer pattern 52 are formed by the same processes as those explained in the previous reference. Figures 4 to 15 The second pattern structure 54 and the second filling layer pattern 56 may be formed on the first pattern structure 50 and the first filling layer pattern 52 by processes substantially the same as those explained above. The thickness of the first pattern structure 50 and the thickness of the second pattern structure 54 may be adjusted so that the sum of the thickness of the first pattern structure 50 and the thickness of the second pattern structure 54 may be substantially the same as the desired thickness of the beam splitter 58.

[0089] Fig.17 is a cross-sectional view illustrating a beam splitter included in an image sensor according to example embodiments.

[0090] Reference Fig.17 , the beam splitter 62 may have a structure in which the first pattern structure 50 and the second pattern structure 60a are arranged.

[0091] The first filling layer pattern 52 may be arranged on both sides of the first pattern structure 50. The first pattern structure 50 and the first filling layer pattern 52 may be similar to those previously described with reference to Fig.16The explained first pattern structure 50 and the first filling layer pattern 52 have substantially the same structure.

[0092] The second pattern structure 60a may be disposed on the first pattern structure 50. In example embodiments, the second pattern structure 60a may include a single refraction layer pattern. Therefore, the refraction layer pattern may not have a grain boundary extending in a vertical direction.

[0093] The refractive layer pattern may include a transparent material having a refractive index in the range of 2.0 to 3.0. Examples of the transparent material may include metal oxides such as titanium oxide, niobium oxide, etc. The refractive layer pattern may include a material that is the same as or different from at least a portion of the material included in the first pattern structure 50.

[0094] In example embodiments, the height of the second pattern structure 60 a may be the same as or different from the height of the first pattern structure 50 .

[0095] The second filling layer pattern 56 may be arranged on both sides of the second pattern structure 60a. For example, the second filling layer pattern 56 may include silicon oxide. The upper surface of the second pattern structure 60a and the upper surface of the second filling layer pattern 56 may be arranged on the same plane to be continuously connected to each other.

[0096] The second pattern structure 60 a may be properly aligned with the upper surface of the first pattern structure 50 , or may be shifted relative to the upper surface of the first pattern structure 50 , depending on the position of the pixel in the image sensor.

[0097] Fig.18 and Fig.19 is a cross-sectional view illustrating a method for forming a beam splitter included in an image sensor according to example embodiments.

[0098] A first pattern structure 50 and a first filling layer pattern 52 are formed on the lower layer 15. Figures 4 to 15 Substantially the same processes as those explained above form the first pattern structure 50 and the first filling layer pattern 52. The first pattern structure 50 may have a predetermined thickness less than a target thickness of the beam splitter.

[0099] Reference Fig.18 A refraction layer 60 is formed on the first pattern structure 50 and the first filling layer pattern 52. For example, the refraction layer 60 may be formed by atomic layer deposition (ALD).

[0100] Reference Fig.19 A mask pattern (not shown) is formed on the refraction layer 60. The mask pattern may include a photoresist pattern formed by a photolithography process. The refraction layer 60 may be etched using the mask pattern as an etching mask to form a second pattern structure 60a.

[0101] Reference Fig.17 A second filling layer may be formed to cover the second pattern structure 60a. For example, the second filling layer may include silicon oxide. For example, the second filling layer may include an SOG layer.

[0102] The upper surface of the second pattern structure 60a and the upper surface of the second filling layer are planarized so that the upper surface of the second pattern structure 60a can be flat. Therefore, the second filling layer pattern 56 can be formed on both sides of the second pattern structure 60a. The planarization process may include a chemical mechanical polishing process or an etch-back process. When the planarization process is performed, the upper portion of the second pattern structure 60a may be partially removed. Therefore, the height of the second pattern structure 60a can be reduced.

[0103] Fig. 20 is a cross-sectional view illustrating a beam splitter included in an image sensor according to example embodiments.

[0104] Reference Fig. 20 The beam splitter 72 may have a structure in which the first pattern structure 70a and the second pattern structure 54 are arranged. The first filling layer pattern 52 may be arranged on both sides of the first pattern structure 70a, and the second filling layer pattern 56 may be arranged on both sides of the second pattern structure 54.

[0105] The first pattern structure 70a and the first filling layer pattern 52 may be similar to those previously described with reference to Fig.17 The explained second pattern structure 60a and the second filling layer pattern 56 have substantially the same structure. Therefore, the first pattern structure 70a may be formed of a single refractive layer pattern. Therefore, the refractive layer pattern may not have a grain boundary extending in a vertical direction.

[0106] The second pattern structure 54 may be arranged on the first pattern structure 70a. The second pattern structure 54 and the second filling layer pattern 56 may be arranged on the first pattern structure 70a. Fig.17 The first pattern structure 50 and the first filling layer pattern 52 explained have substantially the same structure. Therefore, the second pattern structure 54 may have a shape in which a plurality of refractive layer patterns 54a and 54b are arranged in a lateral direction. Therefore, the refractive layer patterns 54a and 54b may form a boundary extending in a vertical direction. Therefore, a grain boundary extending in a vertical direction may be formed at an interface between the refractive layer patterns 54a and 54b.

[0107] Depending on the position of a pixel in the image sensor, a lower surface of the second pattern structure 54 may coincide with an upper surface of the first pattern structure 70 a or may be displaced relative to the upper surface of the first pattern structure 70 a .

[0108] To form the beam splitter 72, the same method as previously described with reference to Fig.18 and Fig.19The first pattern structure 70a and the first filling layer pattern 52 are formed by substantially the same processes as those explained in the previous reference. Figures 4 to 15 The second pattern structure 54 and the second filling layer pattern 56 may be formed on the first pattern structure 70 a and the first filling layer pattern 52 by substantially the same processes as those explained above.

[0109] The beam splitter according to the example embodiment explained above may be arranged in an image sensor having various structures. Therefore, the structure of the image sensor is not particularly limited. Hereinafter, some embodiments of an image sensor including a beam splitter according to the example embodiment will be described.

[0110] Fig.21 is a cross-sectional view illustrating an image sensor according to example embodiments.

[0111] Fig.21 The image sensor shown may be a back-illuminated CMOS image sensor.

[0112] Reference Fig.21 , the image sensor may include a plurality of unit pixels arranged in a matrix configuration. Each unit pixel may include a photodiode 104 arranged in a semiconductor substrate 100, a color filter 116 on a first surface 1 of the semiconductor substrate 100, and a beam splitter 120 arranged on the color filter 116. A transistor (not shown) and a wiring structure 108 may be arranged on a second surface 2 of the semiconductor substrate 100.

[0113] A deep trench isolation pattern 102 may be arranged in the semiconductor substrate 100 to separate individual unit pixel regions. The deep trench isolation pattern 102 may be arranged in a first trench that passes through the semiconductor substrate 100 from the second surface 2 to the first surface 1. In example embodiments, the deep trench isolation pattern 102 may include an insulating spacer (not shown) and a conductive pattern, for example, including polysilicon arranged on the insulating spacer to fill the first trench. The deep trench isolation pattern 102 may have a shape whose inner width decreases from the second surface 2 toward the first surface 1 in the semiconductor substrate 100.

[0114] The photodiode 104 may be arranged in each unit pixel region. The photodiode 104 may include an impurity region. The floating diffusion region 106 may be arranged in a portion adjacent to the second surface 2 in the semiconductor substrate 100. For example, the floating diffusion region 106 may be doped with n-type impurities.

[0115] Even though not shown, a transfer transistor, a reset transistor, a selection transistor, etc. may be arranged on the second surface 2 of the semiconductor substrate 100 .

[0116] A first interlayer insulating layer 110 may be disposed on the second surface 2 of the semiconductor substrate 100 to cover the transistor. A wiring structure 108 may be disposed on and in the first interlayer insulating layer 110. The wiring structure 108 may be electrically connected to the transistor and the floating diffusion region 106.

[0117] A second interlayer insulating layer 112 may be disposed on the first surface 1 of the semiconductor substrate 100. A color filter 116 may be disposed on the second interlayer insulating layer 112 to face the photodiode 104. For example, the color filter 116 may include a red filter R, a blue filter B, and a green filter G. The color filters may be arranged in a matrix configuration.

[0118] The red filter R, the green filter G, and the blue filter B may be respectively arranged in the holes formed by the insulating fence 114. For example, the insulating fence 114 in a mesh shape may be arranged between the red filter R, the green filter G, and the blue filter B. For example, the insulating fence 114 may include silicon oxide. Due to the provision of the insulating fence 114, crosstalk defects may be reduced and / or prevented.

[0119] A planarization layer 118 may be disposed on the color filter 116 and the insulating barrier 114 .

[0120] The beam splitter 120 may be disposed on the planarization layer 118. The beam splitter 120 may split the incident light so that red light may enter the red filter R, blue light may enter the blue filter B, and green light may enter the green filter G.

[0121] In an example embodiment, the beam splitter 120 may be formed on the color filter 116 at a position similar to that previously described with reference to FIG. Figure 2 The location of the explanation is the same.

[0122] In an example embodiment, the beam splitter 120 may have the same Figure 1 , Fig.16 and Fig.17 The filling layer pattern 122 may be arranged on both sides of the beam splitter 120 .

[0123] A capping layer 124 may be disposed on the beam splitter 120 and the filling layer pattern 122. The capping layer 124 may include silicon oxide.

[0124] A microlens 126 may be disposed on the capping layer 124. In some embodiments, the microlens 126 may be omitted.

[0125] Fig. 22 is a cross-sectional view illustrating an image sensor according to example embodiments.

[0126] Fig. 22 The image sensor shown may have Fig.21The image sensor shown is of substantially the same construction except that it does not include a color filter.

[0127] Reference Fig. 22 , the beam splitter 120 may be disposed on the second interlayer insulating layer 112 formed on the first surface of the semiconductor substrate 100 .

[0128] The beam splitter 120 can split the incident light so that red light, blue light and green light can enter different photodiodes, respectively. For example, the beam splitter 120 can split the incident light so that red light can enter the first photodiode 104a, green light can enter the second photodiode 104b, and blue light can enter the third photodiode 104c.

[0129] In an example embodiment, the beam splitter 120 may have the same Figure 1 , Fig.16 and Fig.17 The filling layer pattern 122 may be arranged on both sides of the beam splitter 120 .

[0130] Fig.23 is a cross-sectional view illustrating an image sensor according to example embodiments.

[0131] Fig.23 The image sensor shown may include an organic photodiode.

[0132] Reference Fig.23 The image sensor may include a plurality of unit pixels arranged in a matrix configuration. The unit pixel may include an organic photodiode 232, a color filter 216, a beam splitter 220, and a lower photodiode 204. A transistor and a wiring structure 208 may be arranged on the second surface 2 of the semiconductor substrate 200.

[0133] A deep trench isolation pattern 202 may be disposed in the semiconductor substrate 200 to separate the respective unit pixel regions. The deep trench isolation pattern 202 may be disposed in a first trench passing through the semiconductor substrate 200 from the second surface 2 to the first surface 1 .

[0134] The lower photodiode 204 may be arranged in each unit pixel region. The lower photodiode 204 may be arranged in the semiconductor substrate 200. The lower photodiode 204 may include an impurity region. The floating diffusion region 206 may be arranged in a portion adjacent to the second surface 2 in the semiconductor substrate 200. For example, the floating diffusion region 206 may be doped with n-type impurities.

[0135] A transfer transistor, a reset transistor, a selection transistor, etc. may be arranged on the second surface 2 of the semiconductor substrate 200 .

[0136] A first interlayer insulating layer 210 may be disposed on the second surface 2 of the semiconductor substrate 200 to cover the transistor. A wiring structure 208 may be disposed on and in the first interlayer insulating layer 210. The wiring structure 208 may be electrically connected to the transistor and the floating diffusion region 206.

[0137] A second interlayer insulating layer 212 may be disposed on the first surface 1 of the semiconductor substrate 200. A color filter 216 may be disposed on the second interlayer insulating layer 212. For example, the color filter 216 may include a red filter R and a blue filter B. The color filter 216 may be arranged in a matrix configuration. The red filter R and the blue filter B may be disposed in holes formed by the insulating fence 214, respectively.

[0138] The planarization layer 218 may be arranged to cover the color filter 216. The beam splitter 220 may be arranged on the planarization layer 218. The beam splitter 220 may split the incident light so that the red light may enter the red filter R and the blue light may enter the blue filter B.

[0139] In an example embodiment, the beam splitter 220 may have the same Figure 1 , Fig.16 , Fig.17 and Fig. 20 The filling layer patterns 222 may be arranged on both sides of the beam splitter 220 .

[0140] A third interlayer insulating layer 224 may be disposed on the beam splitter 220 and the filling layer pattern 222. For example, the third interlayer insulating layer 224 may include silicon oxide.

[0141] The organic photodiode 232 may be disposed on the third interlayer insulating layer 224 .

[0142] The organic photodiode 232 may have a structure including a lower transparent electrode 226, an organic layer 228, and an upper transparent electrode layer 230. The lower transparent electrode 226 may be arranged to be spaced apart from and face the corresponding color filter 216. In example embodiments, one color filter 216 and one lower transparent electrode 226 may be arranged to face each other in each unit pixel region.

[0143] The organic photodiodes 232 may be spaced apart from each other by the lower transparent electrode 226. Although not shown, the lower transparent electrode 226 may be electrically connected to the second surface of the semiconductor substrate 200 through a through silicon via contact and a plurality of via contacts. Thus, the lower transparent electrode 226 may be electrically connected to the wiring structure 208.

[0144] The lower transparent electrode 226 may be disposed in the opening formed in the third interlayer insulating layer 224. In addition, an upper surface of the lower transparent electrode 226 and an upper surface of the third interlayer insulating layer 224 may be coplanar.

[0145] Adjacent organic photodiodes 232 may share the organic layer 228 and the upper transparent electrode layer 230 .

[0146] For example, the lower transparent electrode 226 and the upper transparent electrode layer 230 may include ITO, IZO, ZnO, SnO 2 , ATO (antimony-doped tin oxide), AZO (aluminum-doped zinc oxide), GZO (gallium-doped zinc oxide), TiO 2 , FTO (fluorine-doped tin oxide), etc.

[0147] The organic layer 228 may be disposed on the lower transparent electrode 226 and the third interlayer insulating layer 224. The organic layer 228 may include an organic material that causes photoelectric conversion in response to light having a specific wavelength. For example, the organic layer 228 may cause photoelectric conversion in response to green light. Therefore, the organic layer 228 may function as a green filter as well as a photodiode.

[0148] The organic layer 228 may be implemented by a combination of an organic material that donates electrons and an organic material that accepts electrons. For example, the organic layer 228 may have a single layer structure or a multilayer structure in which a p-type semiconductor material and an n-type semiconductor material form a pn flat junction or a bulk heterojunction.

[0149] A capping layer 234 may be disposed on the upper transparent electrode layer 230. The capping layer 234 may include silicon oxide.

[0150] A microlens 236 may be disposed on the capping layer 234. In some embodiments, the microlens 236 may be omitted.

[0151] In an image sensor including an organic photodiode, green light entering the organic layer 228 may cause photoelectric conversion to generate photoelectrons. In addition, red light and blue light may be split by the beam splitter 220 disposed under the organic layer 228 to enter the red filter and the blue filter, respectively. Therefore, the amount of light absorbed by the red filter and the blue filter may be reduced. Therefore, the image sensor may have high sensitivity.

[0152] Fig.24 is a cross-sectional view illustrating an image sensor according to example embodiments.

[0153] Fig.24 The image sensor shown may have Fig.23 The image sensors shown are of substantially the same construction except that they do not include a color filter.

[0154] Reference Fig.24 , the beam splitter 220 may be disposed on the second interlayer insulating layer 212 .

[0155] The beam splitter 220 can split the incident light so that red light and blue light can enter the first lower photodiode 204a and the second lower photodiode 204b, respectively. For example, the beam splitter 220 can split the incident light so that red light can enter the first lower photodiode 204a and blue light can enter the second lower photodiode 204b. Green light can be photoelectrically converted by the organic photodiode 232.

[0156] In an example embodiment, the beam splitter 220 may have the same Figure 1 , Fig.16 and Fig.17 The filling layer pattern 222 may be arranged on both sides of the beam splitter 220 .

[0157] It should be understood that when an element is referred to as being "connected to" or "coupled to" another element or "located on" another element, it may be directly connected to or coupled to or located on the other element, or there may be intervening elements. In contrast, when an element is referred to as being "directly connected to" or "directly coupled to" another element, or when an element is referred to as being "in contact with" another element, there are no intervening elements. Other words used to describe the relationship between elements (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.) should be interpreted in the same manner.

[0158] Example embodiments are shown above and should not be construed as limitations of the example embodiments. Although several example embodiments have been described, it should be readily appreciated by those skilled in the art that many modifications in the example embodiments are possible without materially departing from the novel teachings and advantages of the inventive concept. Therefore, all such modifications are intended to be included within the scope of the invention as defined in the claims. In the claims, means-plus-function clauses are intended to cover structures described herein that perform the functions described, and not only structural equivalents but also equivalent structures. Therefore, it should be understood that various example embodiments are shown above and should not be construed as limited to the specific example embodiments disclosed, and that modifications to the disclosed example embodiments and other example embodiments are intended to be included within the scope of the appended claims.

Claims

1. An image sensor, comprising: a plurality of photodiodes arranged on a semiconductor substrate; as well as a beam splitter arranged on the plurality of photodiodes and splitting the incident light according to wavelength so that split lights of different colors enter different photodiodes respectively, Wherein, the beam splitter comprises a first pattern structure having a cross-sectional structure in which a plurality of refractive layer patterns are arranged adjacent to each other in a lateral direction; as well as The multiple refraction layer patterns include a first refraction layer pattern arranged in the center, a second refraction layer pattern arranged on a laterally opposite side of the first refraction layer pattern, and a third refraction layer pattern arranged on a laterally opposite side of the first refraction layer pattern outside the second refraction layer pattern, so that a combination of the second refraction layer pattern and the third refraction layer pattern is symmetrically arranged on laterally opposite sides of the first refraction layer pattern.

2. The image sensor according to claim 1, wherein: A width of the combined multiple refraction layer patterns in a horizontal direction is smaller than a height of the combined multiple refraction layer patterns in a vertical direction.

3. The image sensor according to claim 2, wherein: The width of the combined plurality of refraction layer patterns is less than 1 / 2 of the height of the combined plurality of refraction layer patterns.

4. The image sensor according to claim 1, wherein: The refractive layer pattern of the first pattern structure includes a transparent material having a refractive index in the range of 2.0 to 3.

0.

5. The image sensor according to claim 4, wherein: The refractive layer pattern includes titanium oxide or niobium oxide.

6. The image sensor according to claim 1, wherein: The refractive layer patterns adjacent to each other in the first pattern structure include the same transparent material or include different transparent materials.

7. The image sensor according to claim 1, wherein: A grain boundary is formed at an interface between the refractive layer patterns adjacent to each other in the first pattern structure.

8. The image sensor according to claim 1, wherein: The beam splitter further includes a second pattern structure arranged on an upper surface or a lower surface of the first pattern structure; and The second pattern structure includes a plurality of refraction layer patterns that are the same as the first pattern structure or includes a single refraction layer pattern.

9. The image sensor according to claim 8, wherein: The second pattern structure is aligned with an upper surface or a lower surface of the first pattern structure, or is shifted relative to an upper surface or a lower surface of the first pattern structure.

10. The image sensor according to claim 1, wherein: The beam splitter has a grid shape in a plan view.

11. The image sensor according to claim 1, wherein: Color filters are arranged between the plurality of photodiodes and the beam splitter, and the color filters are arranged to be spaced apart from the corresponding photodiodes, respectively, and to face each other.

12. The image sensor according to claim 11, wherein: The color filter includes a red filter, a green filter, and a blue filter arranged to form an array, wherein the beam splitter divides incident light so that red light enters the red filter, green light enters the green filter, and blue light enters the blue filter.

13. The image sensor according to claim 12, wherein: The beam splitter is spaced apart from the color filter and is arranged to cross the green filter in a diagonal direction on the green filter; as well as The first refraction layer pattern has a grid shape, and the second refraction layer pattern and the third refraction layer pattern are sequentially formed in the grid of the first refraction layer pattern, so that the orthographic projection of the beam splitter on the semiconductor substrate covers the green filter.

14. The image sensor according to claim 1, further comprising: Filling layer patterns are arranged on both sides of the beam splitter, wherein an upper surface of the beam splitter and an upper surface of the filling layer patterns are arranged on the same plane.

15. The image sensor according to claim 1, further comprising: an organic photodiode disposed on the beam splitter; as well as The organic layer of the organic photodiode performs photoelectric conversion on green light to generate electrons, and the beam splitter splits the red light and the blue light so that the red light and the blue light enter different photodiodes respectively.

16. The image sensor according to claim 1, further comprising: A microlens is arranged on the beam splitter.

17. An image sensor comprising: A plurality of photodiodes are respectively arranged in unit pixel regions of a semiconductor substrate; as well as A beam splitter is arranged on the first surface of the semiconductor substrate and is spaced apart from the plurality of photodiodes, the beam splitter splitting the incident light according to wavelengths so that split lights of different colors enter different photodiodes respectively; and wherein the beam splitter comprises a first pattern structure in which a boundary extending in a vertical direction is formed between two of the plurality of refractive layer patterns; and The multiple refraction layer patterns include a first refraction layer pattern arranged in the center, a second refraction layer pattern arranged on a laterally opposite side of the first refraction layer pattern, and a third refraction layer pattern arranged on a laterally opposite side of the first refraction layer pattern outside the second refraction layer pattern, so that a combination of the second refraction layer pattern and the third refraction layer pattern is symmetrically arranged on laterally opposite sides of the first refraction layer pattern.

18. The image sensor according to claim 17, further comprising: an isolation pattern arranged in the semiconductor substrate to separate the unit pixel regions; as well as A wiring structure is arranged on the second surface of the semiconductor substrate.

19. The image sensor according to claim 18, further comprising: an organic photodiode disposed on the beam splitter; as well as The organic layer of the organic photodiode performs photoelectric conversion on green light to generate electrons, and the beam splitter splits the red light and the blue light so that the red light and the blue light enter different photodiodes respectively.

20. The image sensor according to claim 17, wherein: Color filters are arranged between the plurality of photodiodes and the beam splitter, and the color filters are arranged to be spaced apart from the corresponding photodiodes, respectively, and to face each other.

21. The image sensor according to claim 20, wherein: The color filter includes a red filter, a green filter, and a blue filter arranged to form an array, wherein the beam splitter divides incident light so that red light enters the red filter, green light enters the green filter, and blue light enters the blue filter.

22. An image sensor, comprising: A plurality of photodiodes are respectively arranged in unit pixel regions of a semiconductor substrate; as well as a beam splitter disposed on the first surface of the semiconductor substrate and spaced apart from the plurality of photodiodes, the beam splitter splitting the incident light according to wavelengths so that split lights of different colors enter different photodiodes respectively; wherein the beam splitter comprises a first refraction pattern structure having a cross-sectional structure in which a plurality of refraction layer patterns are stacked in a lateral direction relative to each other; as well as The multiple refraction layer patterns include a first refraction layer pattern arranged in the center, a second refraction layer pattern arranged on a laterally opposite side of the first refraction layer pattern, and a third refraction layer pattern arranged on a laterally opposite side of the first refraction layer pattern outside the second refraction layer pattern, so that a combination of the second refraction layer pattern and the third refraction layer pattern is symmetrically arranged on laterally opposite sides of the first refraction layer pattern.

23. The image sensor according to claim 22, wherein: Color filters are arranged between the plurality of photodiodes and the beam splitter, and the color filters are arranged to be spaced apart from the corresponding photodiodes, respectively, and to face each other.

24. The image sensor according to claim 23, wherein: The color filter includes a red filter and a blue filter arranged to form an array, wherein the beam splitter splits incident light so that red light enters the red filter and blue light enters the blue filter.

Images