Image sensor and method for manufacturing color router for image sensor

Abstract

Provided is an image sensor, according to an embodiment, in which a plurality of pixels are arranged, each of the plurality of pixels comprising: a photo detection layer including a plurality of photo detectors; and a color router disposed on the photo detection layer and having arranged therein a first dielectric having a first permittivity and a second dielectric having a second permittivity, wherein the image sensor includes a plurality of interlayers disposed between the color routers of the plurality of pixels to prevent light incident on the color routers from passing to an adjacent color router.

Description

Method for manufacturing an image sensor and a color router for the image sensor

[0001] The present invention relates to an image sensor including a color router.

[0002] Typically, an image sensor is composed of an array of micro lenses and a color filter, but in this case, the incident light loss reaches 66%, meaning that more than half of the light incident on the image sensor is lost.

[0003] To this end, research on image sensors based on color routers has been actively conducted recently, and a method has been proposed to avoid 66% incident light loss by replacing existing color filters with color routers of sub-wavelength structure.

[0004] However, existing color router-based image sensors are designed with a periodic structure, which inevitably causes optical crosstalk problems between adjacent pixels.

[0005] An image sensor capable of reducing optical crosstalk by introducing an interlayer between adjacent pixels when implementing a color router, and a method for manufacturing a color router capable of preventing interference between pixels by utilizing a Gaussian beam without an interlayer are provided.

[0006] In an image sensor having a plurality of pixels arranged according to one embodiment, each of the plurality of pixels includes: a photodetector layer including a plurality of photodetectors; and a color router disposed on the photodetector layer, the color router having a first dielectric having a first dielectric constant and a second dielectric having a second dielectric constant arranged therein, wherein the image sensor includes a plurality of interlayers disposed between the color routers of each of the plurality of pixels to prevent light incident on the color router from passing to an adjacent color router.

[0007] The above photodetector layer may include a plurality of deep trench isolation (DTI) elements positioned between the plurality of photodetectors to prevent light incident on a photodetector from passing to an adjacent photodetector.

[0008] Each of the above plurality of interlayers may be positioned on a DTI positioned between two photodetectors that are adjacent to each other but included in different pixels.

[0009] Each of the above multiple interlayers can be provided with an air gap.

[0010] Each of the above multiple interlayers can be made of SiO2 or metal.

[0011] The above metal may be tungsten.

[0012] The color router is formed of the first dielectric and includes a plurality of vertically stacked medium layers, and each of the plurality of medium layers can form a scattering pattern including a plurality of scatterers formed of the second dielectric.

[0013] A method for manufacturing a router according to one embodiment, which is arranged on a light detection layer including a plurality of photodetectors and routes each signal of a different wavelength included in incident light to a corresponding photodetector, comprises: generating a design for a structure of the color router; forming the color router such that a first dielectric having a first permittivity and a second dielectric having a second permittivity are arranged therein in response to the design; wherein generating the design for the structure of the color router comprises: determining a candidate design in which a dielectric is arranged therein; and repeatedly performing a forward simulation in which light is irradiated to the plurality of photodetectors through the candidate design and a backward simulation in which light is irradiated from the plurality of photodetectors to the candidate design, thereby adjusting a dielectric distribution of the candidate design in a direction in which a corresponding signal intensity in each of the plurality of photodetectors is maximized; wherein performing the forward simulation comprises performing a simulation in which light irradiated from a Gaussian beam light source is irradiated to the plurality of photodetectors through the candidate design.

[0014] Performing the above forward simulation and the above backward simulation may include performing the simulation with a color router located at the center in a structure in which color routers corresponding to one pixel are repeatedly arranged as the candidate design.

[0015] Performing the above forward simulation and the above backward simulation may include performing the simulation by placing a perfectly matched layer (PML) at the end of a structure in which color routers corresponding to one pixel are repeatedly arranged.

[0016] A method for manufacturing a color router according to one embodiment, which is arranged on a light detection layer including a plurality of photodetectors and routes each signal of a different wavelength included in incident light to a corresponding photodetector, comprises: generating a design for a structure of the color router; forming the color router such that a first dielectric having a first permittivity and a second dielectric having a second permittivity are arranged therein in response to the design; wherein generating the design for the structure of the color router comprises: determining a candidate design in which a dielectric is arranged therein; and repeatedly performing a forward simulation in which light is irradiated to the plurality of photodetectors through the candidate design and a reverse simulation in which light is irradiated from the plurality of photodetectors to the candidate design, thereby adjusting a dielectric distribution of the candidate design in a direction in which a corresponding signal intensity in each of the plurality of photodetectors is maximized; wherein performing the forward simulation and the reverse simulation comprises performing a simulation by arranging an interlayer on a side of the candidate design so as to prevent light incident on the candidate design from escaping to the side of the candidate design.

[0017] Performing the above forward simulation and the above backward simulation may include performing the simulation with the interlayer as an air gap.

[0018] Performing the above forward simulation and the above reverse simulation may include performing the simulation using the interlayer as SIO2 or metal.

[0019] Performing the above forward simulation and the above backward simulation may include performing the simulation using the interlayer as tungsten.

[0020] Performing the above forward simulation may include performing a simulation in which light irradiated from a Gaussian beam light source is irradiated to the plurality of photodetectors through the candidate design.

[0021] According to an embodiment of the present invention, an image sensor is provided, and when implementing a color router, an interlayer between adjacent pixels can be introduced to reduce optical crosstalk, and according to an embodiment of the present invention, a method of manufacturing a color router is provided, and interference between pixels can be prevented by utilizing a Gaussian beam without an interlayer.

[0022] FIG. 1 is a cross-sectional view of an image sensor according to one embodiment.

[0023] FIG. 2 is a cross-sectional view of a color router according to one embodiment when it is provided with a plurality of medium layers.

[0024] FIG. 3 is a flowchart of a method for manufacturing a color router according to one embodiment.

[0025] Figure 4 is a flowchart of a method for designing a color router according to one embodiment.

[0026] FIG. 5 and FIG. 6 are drawings for explaining a case where a color router according to one embodiment is designed by a backpropagation method.

[0027] Figure 7 illustrates a case where a color router according to one embodiment is designed by simulation using an interlayer of an air gap.

[0028] Figure 8 illustrates the routing effect when a color router according to one embodiment is designed by simulation using an interlayer of an air gap.

[0029] Figure 9 illustrates a case where a color router according to an embodiment is designed by simulation using an interlayer of tungsten.

[0030] Figure 10 illustrates the routing effect when a color router according to one embodiment is designed by simulation using an interlayer of tungsten.

[0031] Figure 11 illustrates a case where a color router according to one embodiment is designed by simulation using a Gaussian beam light source.

[0032] Figure 12 illustrates the routing effect when a color router according to one embodiment is designed by simulation using a Gaussian beam light source.

[0033] Figure 13 illustrates a case where a color router according to one embodiment is designed by simulation using an interlayer and a Gaussian beam light source.

[0034] Figure 14 illustrates a case where a color router according to one embodiment is designed in 3D by simulation using interlayers.

[0035] Figure 15 illustrates the routing effect when a color router according to one embodiment is designed in 3D by simulation using interlayers.

[0036] Figure 16 illustrates a case where a color router according to one embodiment is designed in 3D by simulation using a Gaussian beam light source.

[0037] Figure 17 illustrates the routing effect when a color router according to one embodiment is designed in 3D by simulation using a Gaussian beam light source.

[0038] The embodiments described in this specification and the configurations illustrated in the drawings are merely preferred examples of the disclosed invention, and there may be various modified examples that can replace the embodiments and drawings of this specification at the time of filing of this application.

[0039] Throughout this specification, whenever an element is referred to as being positioned on another element, this includes both the meaning that the element is positioned directly on the other element or that additional elements may be interposed between the elements.

[0040] In addition, the terminology used in this specification is used to describe embodiments and is not intended to limit and / or restrict the disclosed invention. The singular expression includes plural expressions unless the context clearly indicates otherwise. In this specification, the terms "comprises" or "has" and the like are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0041] Additionally, terms including ordinal numbers, such as "first," "second," etc., used herein may be used to describe various components; however, the components are not limited by these terms, and these terms are used only to distinguish one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

[0042] Hereinafter, embodiments according to the present invention will be described in detail with reference to the attached drawings.

[0043] FIG. 1 is a cross-sectional view of an image sensor according to one embodiment, and FIG. 2 is a cross-sectional view of a color router according to one embodiment when the color router is provided with a plurality of medium layers.

[0044] Referring to FIG. 1, an image sensor (1) according to one embodiment may have a plurality of pixels arranged, and each pixel includes a red subpixel, a green subpixel, and a blue subpixel.

[0045] At this time, each of the plurality of pixels includes a light detection layer (10) including a plurality of light detectors (11R, 11G, 11B; 11), and a color router (20) arranged on the light detection layer (10) and routing each signal of a different wavelength range included in the incident light to the corresponding light detector (11).

[0046] A light detection layer (10) according to one embodiment may include a deep trench isolation (DTI) (13) disposed between a plurality of light detectors (11) to prevent light incident on a light detector from passing to an adjacent light detector.

[0047] At this time, the DTI (13) includes a first DTI (13a) arranged between a plurality of photodetectors (11) within one pixel, and a second DTI (13b) arranged between two photodetectors that are adjacent to each other but included in different pixels.

[0048] For example, a first DTI (13a) may be positioned between a red light detector (11R) and a green light detector (11G) within one pixel, and between a green light detector (11G) and a blue light detector (11B) within one pixel, and a second DTI (13b) may be positioned between a blue light detector (11B) within one pixel and a red light detector (11R) of an adjacent pixel.

[0049] In Fig. 1, the photodetector (11) is exemplified as being made of Si and the DTI (13) is made of SiO2, but any known type of material that can be used as the photodetector and DTI can be used without limitation in the present invention.

[0050] Among the light incident on the color router (20), red light can be routed to a red light detector (11R), green light can be routed to a green light detector (11G), and blue light can be routed to a blue light detector (11B) among the light incident on the color router (20).

[0051] The color router (20) may have a first dielectric (21a) of a first dielectric constant and a second dielectric of a second dielectric constant arranged therein, through which signals of different wavelength ranges may be routed to corresponding photodetectors (11).

[0052] For example, a color router (20), as shown in FIG. 2, is formed of a first dielectric (21a) and includes a plurality of vertically stacked medium layers (200), and each of the plurality of medium layers (200) can form a scattering pattern including a plurality of scatterers formed of a second dielectric (21b).

[0053] That is, one medium layer (200) may be a layer in which a first dielectric (21a) is used as a body and a second dielectric (21b) is used to fill an empty space within the body to form a scattering pattern.

[0054] In Fig. 2, it is exemplified that the plurality of medium layers (200) can be configured from 2 to 16, but there is no limit to the number of the plurality of medium layers (200).

[0055] The color router (20) can be designed with an internal dielectric array so that each signal in a different wavelength range can be routed to a corresponding photodetector (11), and this will be described in detail later.

[0056] In Fig. 1, the first dielectric (21a) is SiO2 and the second dielectric (21b) is Si3N4, but any two types of dielectrics having different dielectrics can be used without limitation in the present invention.

[0057] In addition, the image sensor (1) according to one embodiment may include a plurality of interlayers (30) arranged between the color routers (20) of each of the plurality of pixels to prevent light incident on the color router from passing to an adjacent color router.

[0058] Through this, the image sensor (1) can reduce optical crosstalk between adjacent pixels even when implementing a color router (20).

[0059] At this time, each of the plurality of interlayers (30) can be placed on a second DTI (13b) placed between two photodetectors that are adjacent to each other but included in different pixels.

[0060] Additionally, the plurality of interlayers (30) may be provided as air gaps, depending on the embodiment. That is, the plurality of interlayers (30) may be provided as air gaps having the lowest refractive index (n=1.0), thereby reducing optical crosstalk between adjacent pixels.

[0061] Additionally, the plurality of interlayers (30) may be formed of SiO2 or metal, depending on the embodiment. This allows the plurality of interlayers (30) to act as physical partitions instead of empty spaces, thereby reducing optical crosstalk between adjacent pixels.

[0062] For example, the metal forming the plurality of interlayers (30) may be tungsten, taking into consideration CMOS compatibility and bonding, etc. However, the metal forming the plurality of interlayers (30) is not limited to tungsten, and any metal with high CMOS compatibility may be used without limitation.

[0063] Below, the manufacturing of the color router (20) will be described in detail.

[0064] Figure 3 is a flowchart of a method for manufacturing a color router (20) according to one embodiment.

[0065] Referring to FIG. 3, a method for manufacturing a color router (20) according to one embodiment may include generating a design for the structure of the color router (20) (310), and forming the color router (20) so that a first dielectric (21a) having a first dielectric constant and a second dielectric (21b) having a second dielectric constant are arranged therein in response to the design (320).

[0066] For example, when a design for the structure of a color router (20) is created, the color router (20) can be formed by arranging the first dielectric (21a) and the second dielectric (21b) so as to correspond to the dielectric arrangement in the design. Specifically, as shown in FIG. 2, a plurality of medium layers (200) formed of the first dielectric (21a) are stacked, and each of the stacked medium layers (200) can form a scattering pattern of the second dielectric (21b) corresponding to the dielectric arrangement in the design.

[0067] Below, the design of the color router (20) will be described in detail.

[0068] FIG. 4 is a flowchart of a method for designing a color router (20) according to one embodiment, and FIGS. 5 and 6 are drawings for explaining a case where a color router (20) according to one embodiment is designed by a backpropagation method.

[0069] The design of the color router (20) is simulated by a known type of electronic device using electromagnetic simulation, for example, full-wave simulation using the finite difference time domain (FDTD) method. However, there is no limitation on the type of electromagnetic simulation, and finite difference frequency domain, finite elements, etc. can be used.

[0070] Referring to FIG. 4, a design method of a color router (20) according to one embodiment may determine a candidate design in which a dielectric is arranged inside (410), perform a forward simulation in which light is irradiated to a plurality of photodetectors (11) through the candidate design (420), perform a reverse simulation in which light is irradiated from a plurality of photodetectors (11) to the candidate design (430), and determine a performance index corresponding to a corresponding signal intensity in each of the plurality of photodetectors (11) (440).

[0071] That is, the design method of the color router (20) can be achieved by using the adjoint method, which can calculate the gradient for all structural degrees of freedom within a pair of forward and backward simulations, thereby performing optimization of the meta-optical structure.

[0072] At this time, in the forward simulation, as shown in (a) of Fig. 5, light is irradiated to multiple photodetectors (11) through the candidate design, and the center of the subpixel (center of the photodetector (11)) corresponding to each photosensitive area (x R , x G , x B ) in the electric field strength (E dir (x R ), E dir (x G ), E dir (x B )) can be decided.

[0073] In addition, in the reverse simulation, as shown in (b) of Fig. 5, light is irradiated from multiple photodetectors (11) to the candidate design, and the electric field intensity (E) at each point (x') inside the candidate design of the color router (20) is adj (x')) can be determined.

[0074] Specifically, in the reverse simulation, the backpropagation source (J) is based on <Mathematical Formula 1> adj ) can be determined, and conjugated The dipoles (P1, P2, P3, P4) with the field size are back-propagated to the candidate design of the color router (20), and the electric field intensity (E) at each point (x') inside the candidate design is adj (x')) can be determined.

[0075]

[0076] At this time, F is a figure of merit (FOM) of intensity maximization for the center of the subpixel corresponding to the photosensitive area of ​​each wavelength, and may be a value obtained by adding the corresponding signal intensities from each of the plurality of photodetectors (11), as in <Mathematical Formula 2>.

[0077]

[0078] α, β, and γ are normalization factors, which were used to optimize evenly for each wavelength band because the airy disk profile varies depending on the wavelength, and thus the intensity of light collected at the designated focal point varies.

[0079] Also, in the simulation, as shown in (c) of Fig. 5, the internal permittivity of the candidate design The slope of the performance index (FOM) for the change can be calculated by <Mathematical Formula 3>.

[0080] That is, in the simulation, the goal is to find a dielectric distribution within the candidate design that can maximize the figure of merit (FOM), and by measuring the figure of merit (FOM) value through forward simulation and performing backward simulation by positioning the backpropagation source in the area where the figure of merit (FOM) is measured by utilizing Lorentz reciprocity, the rate of change in the figure of merit (FOM) according to the change in the dielectric distribution within the candidate design can be calculated.

[0081] In the simulation, the dielectric distribution of the candidate design is adjusted in a direction that maximizes the figure of merit (FOM) (450), and steps 420 to 450 are repeated until the number of simulations reaches a set number (example of 460), thereby determining the candidate design as the design of the color router (20) (470). At this time, the set number is a value preset in the design stage and can be set to various values ​​by the user.

[0082] That is, as illustrated in Fig. 6, by repeatedly performing forward simulation (420) and backward simulation (430) until the FOM is maximized, the candidate design is transformed into a completely binary material composed of the first dielectric (21a) and the second dielectric (21b).

[0083] FIG. 7 illustrates a case where a color router (20) according to one embodiment is designed by simulation using an interlayer (30) of an air gap, FIG. 8 illustrates a routing effect when a color router (20) according to one embodiment is designed by simulation using an interlayer (30) of an air gap, FIG. 9 illustrates a case where a color router (20) according to one embodiment is designed by simulation using an interlayer (30) of tungsten, and FIG. 10 illustrates a routing effect when a color router (20) according to one embodiment is designed by simulation using an interlayer (30) of tungsten.

[0084] Referring to FIGS. 7 to 10, performing forward simulation and backward simulation among the design methods of a color router (20) according to one embodiment may include performing the simulation by placing an interlayer (30) on the side of the candidate design to prevent light incident on the candidate design of the color router (20) from escaping to the side of the candidate design.

[0085] That is, the design method of a color router (20) according to one embodiment can determine a dielectric distribution within a candidate design that suppresses optical crosstalk between repeated pixels by performing a simulation by placing an interlayer (30) on the side of a candidate design of the color router (20).

[0086] At this time, in the forward simulation using the interlayer (30), according to an embodiment, the light of a plane wave can be simulated to be incident on the photodetector (11) through the candidate design, and according to an embodiment, the light of a Gaussian beam light source can be incident on the photodetector (11) through the candidate design. An embodiment using both the interlayer (30) and the Gaussian beam light source will be described in detail later.

[0087] For example, as illustrated in FIG. 7, a design method of a color router (20) according to one embodiment can perform a simulation by placing an air gap as an interlayer (30) on the side of a candidate design of the color router (20). In other words, performing a forward simulation and a backward simulation can include performing a simulation with the interlayer (30) as an air gap.

[0088] In this way, when the color router (20) is designed by simulation using the interlayer (30) of the air gap, as shown in (a) of Fig. 8, by routing light to the corresponding photodetector (11) according to the wavelength, the light efficiency in each of the red subpixel, green subpixel, and blue subpixel was high even in the periodic structure. At this time, subpixel Eff means the ratio of light transmitted to the subpixel of the appropriate color according to the wavelength among the light transmitted to the entire photosensitive area, and abs Eff means the ratio of light transmitted to the subpixel of the appropriate color among the light incident on the entire color router (20).

[0089] In particular, as shown in (b) of Fig. 8, when the color router (20) is designed by simulation using the interlayer (30) of the air gap, the intensity profile can confirm that the light is well focused on the corresponding photosensitive area with almost no color crosstalk.

[0090] In addition, a design method of a color router (20) according to one embodiment can perform a simulation by placing SiO2 or metal as an interlayer (30) on the side of a candidate design of the color router (20). In other words, performing a forward simulation and a backward simulation can include performing a simulation using SiO2 or metal as the interlayer (30).

[0091] For example, performing forward simulation and backward simulation may include performing simulation with the interlayer (30) made of tungsten, as illustrated in FIG. 9. At this time, in the design of the optimized color router (20), the second dielectric (21b) is positioned vertically without touching the interlayer (30), which is optimized so that light is guided only downward without touching the interlayer (30) as much as possible due to the high absorption rate of tungsten.

[0092] In this way, when the color router (20) is designed by simulation using a tungsten interlayer (30), as shown in (a) of Fig. 10, light is routed to the corresponding photodetector (11) according to wavelength, and the light efficiency in each of the red subpixel, green subpixel, and blue subpixel is high even in a periodic structure.

[0093] In particular, as shown in (b) of Fig. 10, when the color router (20) is designed by simulation using an interlayer (30) of tungsten, the intensity profile can confirm that the light is well focused on the corresponding photosensitive area with almost no color crosstalk.

[0094] In the above, a method for designing a color router (20) using an interlayer (30) has been described. In the following, a method for designing a color router (20) using a Gaussian beam light source will be described.

[0095] FIG. 11 illustrates a case where a color router (20) according to one embodiment is designed by a simulation using a Gaussian beam light source, FIG. 12 illustrates a routing effect when a color router (20) according to one embodiment is designed by a simulation using a Gaussian beam light source, and FIG. 13 illustrates a case where a color router (20) according to one embodiment is designed by a simulation using an interlayer (30) and a Gaussian beam light source.

[0096] Referring to FIG. 11, a method of designing a color router (20) according to one embodiment may include performing a forward simulation in which light irradiated from a Gaussian beam light source is irradiated to a plurality of photodetectors (11) through a candidate design.

[0097] The optimization of the existing color router (20) was impossible to distinguish between pixels without using an interlayer (30) in a periodic environment using a plane wave as the incident wave, and physical constraints had to be imposed to control optical crosstalk between pixels.

[0098] In forward simulation and backward simulation according to one embodiment, a simulation is performed with a color router (20c) located at the center as the candidate design in a structure in which color routers (20) corresponding to one pixel are repeatedly arranged, and by irradiating a Gaussian beam light source with the candidate design corresponding to the color router (20c) located at the center, a plane wave incident only on one pixel located at the center can be imitated, and the degree of design freedom can be increased compared to when an interlayer (30) is used.

[0099] For example, as illustrated in FIG. 11, forward simulation and backward simulation can be performed by irradiating a Gaussian beam light source with a candidate design corresponding to a color router (20c) located in the center among five color routers (20a, 20b, 20c, 20d, 20e) that are repeatedly arranged.

[0100] At this time, in the backpropagation method, the figure of merit (FOM) is measured only at the central pixel that is the target of the Gaussian beam, and in each iteration, the design of the remaining color routers that are repeatedly arranged also changes in accordance with the change in the dielectric distribution of the candidate design corresponding to the central pixel.

[0101] According to one embodiment, performing the forward simulation and the backward simulation includes performing the simulation by placing a perfectly matched layer (PML) at the end of a structure in which color routers (20) corresponding to one pixel are repeatedly arranged. For example, the simulation can be implemented in a limited periodicity region by placing a PML at the end of a color router (20a, 20e) among five color routers (20a, 20b, 20c, 20d, 20e) that are repeatedly arranged, as illustrated in FIG. 11.

[0102] In this way, when a Gaussian beam light source is irradiated to a color router located at the center in a structure in which color routers (20) are repeatedly arranged, as shown in (a) of Fig. 12, light is routed to the corresponding photodetector (11) according to wavelength, and the light efficiency in each of the red subpixel, green subpixel, and blue subpixel is high even in a periodic structure.

[0103] In particular, when a Gaussian beam light source is irradiated to a color router located at the center in a structure in which color routers (20) are repeatedly arranged, as illustrated in (b) of FIG. 12, the intensity profiles for five cycles of the optimized image sensor (1) at three representative wavelengths show that the incident light is successfully routed to the corresponding subpixel without going to the adjacent pixel. In this way, the optimized structure using the Gaussian beam light source suppresses optical crosstalk between pixels without using an interlayer (30) and shows high intra-pixel efficiency.

[0104] In addition, the design method of the color router (20) according to one embodiment can also perform simulation using both the interlayer (30) and the Gaussian beam light source.

[0105] For example, as illustrated in FIG. 13, the simulation can be performed by positioning an interlayer (30) between five color routers (20a, 20b, 20c, 20d, 20e) that are repeatedly arranged, and irradiating a Gaussian beam light source with a candidate design corresponding to a color router (20c) located in the center among the five color routers (20a, 20b, 20c, 20d, 20e).

[0106] The design of a 2D color router (20) has been described above. Below, the design of a 3D color router (20) will be described. The design method of a 3D color router (20) uses the contents of FIGS. 1 to 13, which describe the design of a 2D color router (20), and below, differences that may arise when designing in 3D and the previous description will be described.

[0107] FIG. 14 illustrates a case where a color router (20) according to one embodiment is designed in 3D by simulation using an interlayer (30), FIG. 15 illustrates a routing effect when a color router (20) according to one embodiment is designed in 3D by simulation using an interlayer (30), FIG. 16 illustrates a case where a color router (20) according to one embodiment is designed in 3D by simulation using a Gaussian beam light source, and FIG. 17 illustrates a routing effect when a color router (20) according to one embodiment is designed in 3D by simulation using a Gaussian beam light source.

[0108] The design of the 3D color router (20) is different from the design of the previous 2D color router (20) in that the dielectric distribution can be different at each location within the candidate design and in all three dimensions.

[0109] At this time, the plurality of photodetectors (11) may be provided in a Bayer pattern including one red light detector (11R), two green light detectors (11G), and one blue light detector (11B), as illustrated in Fig. 14. However, any pattern in which the plurality of photodetectors (11) are provided may be used without limitation as long as it is known in advance.

[0110] In a design method of a color router (20) according to one embodiment, while maximizing the intensity for the center of each sub-pixel is used as a figure of merit (FOM), since there are twice as many green sub-pixels as other colors, the intensities corresponding to the two green sub-pixels are added and then divided in half to be equally optimized for each color.

[0111] That is, the performance index (FOM) used in the design of the 3D color router (20) can be as shown in <Mathematical Formula 3>.

[0112]

[0113] At this time, x G1 , x G2 refers to the center of two green subpixels each arranged diagonally. refers to the intensity of the electric field according to the wavelength of the incident wave.

[0114] In a design method of a 3D color router (20) according to one embodiment, as illustrated in FIG. 14, a color router (20) corresponding to one pixel is used as a candidate design, and forward simulation and reverse simulation are repeatedly performed with the candidate design, thereby optimizing the dielectric distribution within the 3D candidate design.

[0115] At this time, interlayers (30) can be placed on four sides of the candidate design corresponding to the 3D color router (20), and the interlayers (30) can be arranged in a form that surrounds the color router. This design enables simulations to be performed and optical crosstalk between pixels can be eliminated.

[0116] In this way, when a 3D color router (20) is designed by simulation using an interlayer (30), as shown in (a) of Fig. 15, light is routed to the corresponding photodetector (11) according to wavelength, and the light efficiency in each of the red subpixel, green subpixel, and blue subpixel is high even in a periodic structure.

[0117] In particular, as shown in (b) of Fig. 15, when a 3D color router (20) is designed by simulation using an interlayer (30), the intensity profile can confirm that the light is well focused on the corresponding photosensitive area with almost no color crosstalk.

[0118] Additionally, the design method of a 3D color router (20) according to one embodiment can be performed by simulation using a Gaussian beam light source.

[0119] For example, as illustrated in FIG. 16, a design method of a 3D color router (20) according to one embodiment performs a simulation by using a color router (20c) located at the center as a candidate design in a structure in which nine 3D color routers (20) are repeated in a 3X3 pattern, and by irradiating a Gaussian beam light source with a candidate design corresponding to the color router (20c) located at the center, a plane wave incident only on one pixel located at the center can be imitated, and the degree of design freedom can be increased compared to when an interlayer (30) is used.

[0120] At this time, in the backpropagation method, the figure of merit (FOM) is measured only at the central pixel that is the target of the Gaussian beam, and in each iteration, the design of the remaining color routers that are repeatedly arranged also changes in accordance with the change in the dielectric distribution of the candidate design corresponding to the central pixel.

[0121] According to one embodiment, performing the forward simulation and the backward simulation includes performing the simulation by placing a perfectly matched layer (PML) at the end of a structure in which color routers (20) corresponding to one pixel are repeatedly arranged.

[0122] In this way, when a Gaussian beam light source is irradiated to a color router located at the center in a structure in which 3D color routers (20) are repeatedly arranged, as shown in (a) of Fig. 17, the light intensity profile confirms that the light is well focused on the corresponding photosensitive area with almost no color crosstalk. In this way, the structure optimized using a Gaussian beam light source suppresses optical crosstalk between pixels without using an interlayer (30) and shows high intra-pixel efficiency.

[0123] In addition, the design method of the color router (20) according to one embodiment can also perform simulation using both the interlayer (30) and the Gaussian beam light source.

[0124] For example, the simulation can be performed by positioning an interlayer between repeatedly arranged 3D color routers (20) and irradiating a Gaussian beam light source with a candidate design corresponding to a color router (20c) positioned at the center of the repeatedly arranged 3D color routers.

[0125] In this case, as shown in (b) of Fig. 17, the intensity profile confirms that the light is well-focused to the corresponding photosensitive region with almost no color crosstalk. In this case, it can be confirmed that the optical crosstalk is further improved compared to (a) of Fig. 17, which is the result of simulation using only a Gaussian beam light source.

[0126] The disclosed embodiments have been described with reference to the attached drawings as described above. Those skilled in the art will understand that the present invention can be implemented in forms other than the disclosed embodiments without altering the technical spirit or essential features of the present invention. The disclosed embodiments are illustrative and should not be construed as limiting.

Claims

1. In an image sensor in which multiple pixels are arranged, Each of the above plurality of pixels, a photodetector layer comprising a plurality of photodetectors; and A color router is disposed on the above light detection layer and includes a first dielectric having a first dielectric constant and a second dielectric having a second dielectric constant arranged therein, The above image sensor, An image sensor comprising a plurality of interlayers arranged between each of the plurality of color routers of the pixels to prevent light incident on the color router from passing to an adjacent color router.

2. In paragraph 1, The above light detection layer, An image sensor comprising a plurality of deep trench isolation (DTI) elements positioned between a plurality of photodetectors to prevent light incident on a photodetector from passing to an adjacent photodetector.

3. In paragraph 2, Each of the above multiple interlayers, An image sensor positioned on a DTI between two photodetectors that are adjacent to each other but contained in different pixels.

4. In paragraph 1, Each of the above multiple interlayers, Image sensor with air gap.

5. In paragraph 1, Each of the above multiple interlayers, Image sensor made of SIO2 or metal.

6. In paragraph 5, The above metal is, Tungsten image sensor.

7. In paragraph 1, The above color router, It comprises a plurality of medium layers vertically stacked and provided with the first dielectric, Each of the above multiple medium layers, An image sensor having a scatterer pattern formed thereon, the scatterer pattern including a plurality of scatterers formed of the second dielectric.

8. A method for manufacturing a color router, which is arranged on a light detection layer including a plurality of light detectors and routes each signal of a different wavelength included in incident light to a corresponding light detector, Create a design for the structure of the above color router; Including forming the color router so that a first dielectric having a first dielectric constant and a second dielectric having a second dielectric constant are arranged inside in response to the above design; Creating a design for the structure of the above color router is: Determine a candidate design in which the genome is arranged internally; By repeatedly performing forward simulation in which light is irradiated to the plurality of photodetectors through the candidate design and reverse simulation in which light is irradiated from the plurality of photodetectors to the candidate design, the dielectric distribution of the candidate design is adjusted in a direction in which the corresponding signal intensity in each of the plurality of photodetectors is maximized; Performing the above forward simulation is as follows: A method for manufacturing a color router, comprising performing a simulation of irradiating light from a Gaussian beam light source to the plurality of photodetectors through the candidate design.

9. In paragraph 8, Performing the above forward simulation and the above backward simulation is as follows: A method for manufacturing a color router, comprising performing a simulation using a color router located at the center as the candidate design in a structure in which color routers corresponding to one pixel are repeatedly arranged.

10. In paragraph 9, Performing the above forward simulation and the above backward simulation is as follows: A method for manufacturing a color router, comprising performing a simulation by placing a PML (perfectly matched layer) at the end of a structure in which color routers corresponding to the above one pixel are repeatedly arranged.

11. A method for manufacturing a color router, which is arranged on a light detection layer including a plurality of light detectors and routes each signal of a different wavelength included in incident light to a corresponding light detector, Create a design for the structure of the above color router; Including forming the color router so that a first dielectric having a first dielectric constant and a second dielectric having a second dielectric constant are arranged inside in response to the above design; Creating a design for the structure of the above color router is: Determine a candidate design in which the genome is arranged internally; By repeatedly performing forward simulation in which light is irradiated to the plurality of photodetectors through the candidate design and reverse simulation in which light is irradiated from the plurality of photodetectors to the candidate design, the dielectric distribution of the candidate design is adjusted in a direction in which the corresponding signal intensity in each of the plurality of photodetectors is maximized; Performing the above forward simulation and the above backward simulation is as follows: A method for manufacturing a color router, comprising performing a simulation by placing an interlayer on the side of the candidate design to prevent light incident on the candidate design from escaping to the side of the candidate design.

12. In paragraph 11, Performing the above forward simulation and the above backward simulation is as follows: A method for manufacturing a color router, including performing a simulation with the above interlayer as an air gap.

13. In paragraph 11, Performing the above forward simulation and the above backward simulation is as follows: A method for manufacturing a color router, comprising performing a simulation using the above interlayer as SIO2 or metal.

14. In paragraph 13, Performing the above forward simulation and the above backward simulation is as follows: A method for manufacturing a color router, comprising performing a simulation using the above interlayer as tungsten.

15. In paragraph 11, Performing the above forward simulation is as follows: A method for manufacturing a color router, comprising performing a simulation of irradiating light from a Gaussian beam light source to the plurality of photodetectors through the candidate design.

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