KR20240002072A - Image sensor including planar nano-photonic microlens array and electronic apparatus including the image sensor - Google Patents

Abstract

An image sensor having a planar nano-optical microlens array and an electronic device including the same are disclosed. The disclosed image sensor includes a planar nano-optical microlens array including a plurality of planar nano-optical microlenses, each of which includes a high-refractive-index nanostructure made of a dielectric material with a relatively high refractive index and a relatively high-refractive-index nanostructure. It includes a low refractive index structure made of a dielectric material with a low refractive index, and at the periphery of the planar nano-optical microlens array, the planar nano-optical microlenses have an asymmetric effective refractive index distribution where the effective refractive index distributions on both sides of the refractive index peak region are different from each other. You can have

Description

Image sensor including planar nano-photonic microlens array and electronic apparatus including the image sensor}

The disclosed embodiments relate to an image sensor having a planar nano-optical microlens array that can easily determine the optical curvature profile of the lens surface using a planar nanostructure, and an electronic device including the same.

As image sensors and imaging modules become increasingly smaller, the chief ray angle (CRA) at the edge of the image sensor tends to increase. As the chief ray angle increases at the edge of the image sensor, the sensitivity of pixels located at the edge of the image sensor decreases. This may cause the edges of the image to become dark. Additionally, additional complex color calculations to compensate for this place a burden on the processor that processes the image and slow down the image processing speed.

An image sensor having a planar nano-optical microlens array that can easily determine the optical curvature profile of the lens surface using a planar nanostructure and an electronic device including the same are provided.

In addition, an image sensor having a planar nano-optical microlens array capable of changing the angle of incidence of incident light incident at a large chief ray angle from the edge of the image sensor to become close to vertical, and an electronic device including the same are provided.

An image sensor according to an embodiment includes a sensor substrate including a plurality of light-sensing cells that sense light; And a planar nano-optical microlens array including a plurality of planar nano-optical microlenses having a nano-pattern structure that focuses light on a corresponding photosensing cell among the plurality of photosensing cells, each planar nano-optical microlens The lens includes a high refractive index nanostructure made of a dielectric material with a relatively high refractive index and a low refractive index structure made of a dielectric material with a relatively low refractive index, and is determined by the ratio of the high refractive index nanostructure to the low refractive index structure. The effective refractive index of the planar nano-optical microlens is highest at the refractive index peak area of the planar nano-optical microlens and gradually decreases around the refractive index peak area, and at the periphery of the planar nano-optical microlens array, the planar nano-optical microlens has an asymmetric effective refractive index distribution, wherein the effective refractive index distribution on the first side of the refractive index peak area is different from the effective refractive index distribution on the second side of the refractive index peak area, and the first side of the refractive index peak area is the second side of the refractive index peak area. It may be closer to the center of the planar nano-optical microlens array than the two sides.

At the periphery of the planar nano-optical microlens array, the refractive index peak area of the planar nano-optical microlens may be located away from the center of the planar nano-optical microlens toward the center of the planar nano-optical microlens array.

At the periphery of the planar nano-optical microlens array, the distance between the refractive index peak area of the planar nano-optic microlens and the center of the planar nano-optic microlens is between the planar nano-optic microlens and the center of the planar nano-optic microlens array. It can get bigger as the distance between .

The peripheral planar nano-optical microlens has a first edge and a second edge opposite the first edge, wherein the first edge is closer to the center of the planar nano-optical microlens array than the second edge, and the second edge is closer to the center of the planar nano-optical microlens array. The slope of the effective refractive index distribution between the first edge and the refractive index peak area may be greater than the slope of the effective refractive index distribution between the second edge and the refractive index peak area.

The planar nano-optical microlens array includes a first planar nano-optical microlens and a second planar nano-optical microlens disposed at the periphery of the planar nano-optical microlens array, and the second planar nano-optical microlens and the planar nano-optical microlens. The distance between the center of the nano-optical microlens array is greater than the distance between the first planar nano-optical microlens and the center of the planar nano-optical microlens array, and the first edge of the second planar nano-optic microlens and the second The slope of the effective refractive index distribution between the refractive index peak area of the planar nano-optical microlens is greater than the slope of the effective refractive index distribution between the first edge of the first planar nano-optical microlens and the refractive index peak area of the first planar nano-optical microlens. It can be big.

The slope of the effective refractive index distribution between the second edge of the second planar nano-optical microlens and the refractive index peak area of the second planar nano-optical microlens is the second edge of the first planar nano-optical microlens and the first plane. It may be smaller than the slope of the effective refractive index distribution between the refractive index peak areas of the nano-optical microlens.

Each planar nano-optical microlens has a first region having the highest effective refractive index, a second region surrounding the first region and having a lower effective refractive index than the first region, and a second region surrounding the second region and having an effective refractive index lower than the second region. It may include a third region with a low refractive index.

At the center of the planar nano-optical microlens array, the refractive index peak area of the planar nano-optical microlens is located at the center of the planar nano-optical microlens, and the planar nano-optical microlens has an effective refractive index distribution symmetrical about the center. You can have it.

At the periphery of the planar nano-optical microlens array, boundaries between the planar nano-optic microlenses may coincide with boundaries between corresponding photo-sensing cells.

At the periphery of the planar nano-optical microlens array, each planar nano-optic microlens may be positioned shifted toward the center of the planar nano-optic microlens array with respect to the corresponding photo-sensing cells.

At the periphery of the planar nano-optical microlens array, the distance by which each planar nano-optical microlens is shifted toward the center of the planar nano-optic microlens array may become larger as the distance from the center of the planar nano-optic microlens array increases. .

The total area of the planar nano-optical microlens array may be smaller than the total area of the sensor substrate.

Each planar nano optical microlens includes a plurality of high refractive index nanostructures having a nanopost shape, and the ratio of the area occupied by the plurality of high refractive index nanostructures to unit area may be highest in the refractive index peak area.

Among the plurality of high refractive index nanostructures, the high refractive index nanostructure with the largest width or diameter may be disposed in the refractive index peak region.

The plurality of high refractive index nanostructures include a first high refractive index nanostructure closer to the center of the planar nano-optical microlens array with respect to the high refractive index nanostructure with the largest width or diameter, and a high refractive index nanostructure with the largest width or diameter. and a second high refractive index nanostructure farther from the center of the planar nano-optical microlens array with respect to the structure, wherein the first high refractive index nanostructure and the second high refractive index nanostructure are the high refractive index nanostructures having the largest width or diameter. It is disposed adjacent to the structure, and the first width or diameter of the first high refractive index nanostructure may be different from the second width or diameter of the second high refractive index nanostructure.

The first width or diameter of the first high refractive index nanostructure may be smaller than the second width or diameter of the second high refractive index nanostructure.

The first pitch between the high refractive index nanostructure with the largest width or diameter and the first high refractive index nanostructure is the same as the second pitch between the high refractive index nanostructure with the largest width or diameter and the 21 high refractive index nanostructures. can do.

At the periphery of the planar nano-optical microlens array, the planar nano-optical microlens includes a plurality of high refractive index nanostructures, and the plurality of high refractive index nanostructures are aligned with the high refractive index nanostructure having the largest width or diameter. A first high refractive index nanostructure closer to the center of the planar nano-optical microlens array and a second high refractive index nanostructure further from the center of the planar nano-optical microlens array for the high refractive index nanostructure with the largest width or diameter. It includes, the first high refractive index nanostructure and the second high refractive index nanostructure are arranged adjacent to the high refractive index nanostructure with the largest width or diameter, and the first width or diameter of the first high refractive index nanostructure is The first pitch between the high refractive index nanostructure having the largest width or diameter and the first high refractive index nanostructure is the same as the second width or diameter of the second high refractive index nanostructure. It may be smaller than the second pitch between the refractive index nanostructure and the 21 high refractive index nanostructures.

Each planar nano optical microlens includes a plurality of high refractive index nanostructures and a plurality of low refractive index structures arranged alternately, and the radial width of the high refractive index nanostructure may be largest at the refractive index peak region.

Each planar nano optical microlens may include one low refractive index nanostructure in the form of a plate and a plurality of high refractive index structures in the shape of a hole.

Each planar nano optical microlens includes a first layer and a second layer stacked on the first layer, and the pattern of the high refractive index nanostructures and the low refractive index structures of the first layer is the high refractive index nanostructure of the second layer. The pattern of the structure and the low refractive index structure may be different.

In the refractive index peak area of each planar nano optical microlens, the high refractive index nanostructures in the first layer and the second layer have the same width, and in the area away from the refractive index peak area, the width of the high refractive index nanostructure in the second layer is This may be smaller than the width of the high refractive index nanostructure of the first layer.

It may further include a convex microlens disposed on each planar nano-optical microlens.

At the center of the planar nano-optical microlens array, the refractive index peak areas of the corresponding planar nano-optical microlenses and the optical axes of the convex microlenses may be aligned to coincide with each other.

At the periphery of the planar nano-optic microlens array, the convex microlenses may be shifted relative to the corresponding planar nano-optic microlenses toward the center of the planar nano-optic microlens array.

It may further include a transparent dielectric layer disposed between the sensor substrate and the planar nano-optical microlens array and having a thickness that increases from the center of the planar nano-optical microlens array toward the periphery.

It further includes a color filter layer disposed on the sensor substrate, wherein the color filter layer includes a plurality of color filters that transmit only light in a specific wavelength band and absorb or reflect light in other wavelength bands, and the planar nano-optical microlens array may be disposed on the color filter layer.

An electronic device according to an embodiment includes an image sensor that converts an optical image into an electrical signal; and a processor that controls the operation of the image sensor and stores and outputs signals generated by the image sensor, wherein the image sensor includes: a sensor substrate including a plurality of light-sensing cells that detect light; And a planar nano-optical microlens array including a plurality of planar nano-optical microlenses having a nano-pattern structure that focuses light on a corresponding photosensing cell among the plurality of photosensing cells, each planar nano-optical microlens The lens includes a high refractive index nanostructure made of a dielectric material with a relatively high refractive index and a low refractive index structure made of a dielectric material with a relatively low refractive index, and is determined by the ratio of the high refractive index nanostructure to the low refractive index structure. The effective refractive index of the planar nano-optical microlens is highest at the refractive index peak area of the planar nano-optical microlens and gradually decreases around the refractive index peak area, and at the periphery of the planar nano-optical microlens array, the planar nano-optical microlens has an asymmetric effective refractive index distribution, wherein the effective refractive index distribution on the first side of the refractive index peak area is different from the effective refractive index distribution on the second side of the refractive index peak area, and the first side of the refractive index peak area is the second side of the refractive index peak area. It may be closer to the center of the planar nano-optical microlens array than the two sides.

An image sensor according to an embodiment includes a pixel array, wherein the pixel array includes: a sensor substrate including a plurality of light-sensing cells that detect light; a color filter layer disposed on the sensor substrate and including a plurality of color filters that transmit light in a specific wavelength band and absorb or reflect light in wavelength bands other than the specific wavelength band; and a planar nano-optical microlens array disposed on the color filter layer and including a plurality of planar nano-optical microlenses having a nano-pattern structure that focuses light on a corresponding photo-sensing cell among the plurality of photo-sensing cells. Each planar nano-optical microlens includes a high refractive index nanostructure made of a dielectric material with a relatively high refractive index and a low refractive index structure made of a dielectric material with a relatively low refractive index, and the The effective refractive index of the planar nano-optical microlens, which is determined by the ratio of the high refractive index nanostructures, is highest at the refractive index peak area of the planar nano-optical microlens and gradually lowers around the refractive index peak area, and the planar nano-optical microlens array At the center, the planar nano-optical microlenses have a symmetrical effective refractive index distribution, and at the periphery of the planar nano-optical microlens array, the planar nano-optical microlenses have an effective refractive index distribution at the first side of the refractive index peak region. having an asymmetric effective refractive index distribution, different from the effective refractive index distribution at the second side of the refractive index peak region, wherein the first side of the index peak region is closer to the center of the planar nano-optic microlens array than the second side of the index peak region. You can.

A planar nano-optical microlens array with a planar nanostructure can easily determine the optical curvature profile of the lens surface using a planar nanostructure. Therefore, it is possible to easily design and manufacture a planar nano-optical microlens with an optimal shape according to the principal ray angle of the incident light incident on the image sensor.

Additionally, the planar nano-optical microlens array according to the disclosed embodiment can change the angle of incidence of incident light incident at a large chief ray angle at the edge of the image sensor to be closer to vertical. In particular, the planar nano-optical microlens array can be equipped with various types of microlenses by considering the change in the angle of the main ray according to various positions on the image sensor. Accordingly, the sensitivity of pixels located at the edges of the image sensor can be improved to be similar to the sensitivity of pixels located at the center of the image sensor.

1 is a block diagram of an image sensor according to an embodiment.
Figure 2 is a conceptual diagram schematically showing a camera module according to an embodiment.
Figure 3 is a cross-sectional view showing a pixel array of an image sensor according to an embodiment.
FIG. 4A is a schematic cross-sectional view of the center of the pixel array of the image sensor shown in FIG. 3.
FIG. 4B exemplarily shows a convex microlens equivalent to the planar nano-optical microlens shown in FIG. 4A.
FIG. 5 is a plan view illustrating the shape of the planar nano-optical microlens shown in FIG. 4A.
FIG. 6 is a plan view exemplarily showing the effective refractive index distribution of the planar nano-optical microlens shown in FIG. 4A.
FIG. 7A is a schematic cross-sectional view of the periphery of the pixel array of the image sensor shown in FIG. 3.
FIG. 7B is a plan view illustrating the shape of the planar nano-optical microlens shown in FIG. 7A.
FIG. 8A is a plan view exemplarily showing the effective refractive index distribution of the planar nano-optical microlens shown in FIG. 7A.
FIGS. 8B and 8C are plan views exemplarily showing the shape of the planar nano-optical microlens shown in FIG. 7A.
FIG. 9 is an exemplary cross-sectional view showing the effective refractive index distribution of the planar nano-optical microlens shown in FIG. 7A.
Figure 10 is a plan view schematically showing a plurality of regions of a nano-optical microlens array according to an embodiment.
11A to 11D are plan views illustrating various shapes of planar nano-optical microlenses according to other embodiments.
12A and 12B are cross-sectional views exemplarily showing the shape of a planar nano-optical microlens according to another embodiment.
Figure 13 is a plan view showing a pixel array of an image sensor according to another embodiment.
FIG. 14 is a schematic cross-sectional view along line AA' of the periphery of the pixel array of the image sensor shown in FIG. 13.
15 to 17 are cross-sectional views exemplarily showing the shape of a planar nano-optical microlens according to another embodiment further comprising a convex microlens.
18 to 21 are cross-sectional views schematically showing a pixel array of an image sensor according to another embodiment.
Figure 22 is a plan view showing a pixel array of an image sensor according to another embodiment.
FIG. 23 is a cross-sectional view taken along line BB' showing an example of the pixel array of the image sensor shown in FIG. 22.
FIG. 24 is a cross-sectional view taken along line BB' showing another example of the pixel array of the image sensor shown in FIG. 22.
Figure 25 is a schematic cross-sectional view of a pixel array of an image sensor according to another embodiment.
26A to 26C exemplarily show various pixel arrangements of a pixel array.
Figures 27a and 27b are conceptual diagrams showing the schematic structure and operation of a color separation lens array according to an embodiment.
FIGS. 28A and 28B are schematic cross-sectional views of a pixel array of an image sensor according to an embodiment, respectively.
Figure 29a is a plan view schematically showing the arrangement of the photo-sensing cells, Figure 29b is a plan view exemplarily showing the arrangement of the nanoposts of the color separation lens array, and Figure 29c is a detailed enlarged view of a portion of Figure 29b. It is a floor plan.
Figure 30a shows the phase distribution of the first and second wavelength light passing through the color separation lens array along the line I-I' of Figure 29b, and Figure 30b shows the phase distribution of the first and second wavelength light passing through the color separation lens array. It shows the phase at the center of the fourth region, and Figure 30c is a diagram showing the phase at the center of the first to fourth regions of the second wavelength light that passed through the color separation lens array.
Figure 30D exemplarily shows the direction of travel of the first wavelength light incident on and around the first region of the color separation lens array of Figures 30A and 30B, and Figure 30E is equivalent to the color separation lens array for the first wavelength light. This is an exemplary diagram showing a micro lens array that acts as an enemy.
Figure 30F exemplarily shows the direction of travel of the second wavelength light incident on and around the second region of the color separation lens array of Figures 30A and 30B, and Figure 30G is equivalent to the color separation lens array for the second wavelength light. This is an exemplary diagram showing a micro lens array that acts as an enemy.
Figure 31a shows the phase distribution of the first and third wavelength light passing through the color separation lens array along the line II-II' of Figure 29b, and Figure 31b shows the phase distribution of the first to third wavelength light passing through the color separation lens array. It shows the phase at the center of the fourth region, and Figure 31c is a diagram showing the phase at the center of the first to fourth regions of the first wavelength light passing through the color separation lens array.
Figure 31D exemplarily shows the direction of travel of the third wavelength light incident on and around the third region of the color separation lens array of Figures 31A and 31B, and Figure 31E is equivalent to the color separation lens array for the third wavelength light. This is an exemplary diagram showing a micro lens array that acts as an enemy.
FIG. 31F exemplarily shows the direction of travel of the first wavelength light incident on and around the fourth region of the color separation lens array of FIGS. 31A and 31B, and FIG. 31G is equivalent to the color separation lens array for the first wavelength light. This is an exemplary diagram showing a micro lens array that acts as an enemy.
Figures 32A to 32C are plan views showing changes in the arrangement shape of nanoposts of the color separation lens array according to position on the pixel array.
Figure 33 is a cross-sectional view showing a schematic structure of a pixel array of an image sensor according to another embodiment.
Figure 34 is a cross-sectional view showing a schematic structure of a pixel array of an image sensor according to another embodiment.
Figure 35 is a plan view exemplarily showing the shift form of nanoposts arranged two-dimensionally in a color separation lens array.
Figures 36a and 36b are plan views exemplarily showing the unit pattern form of a color separation lens array according to another embodiment that can be applied to a Bayer pattern image sensor.
Figure 37 is a cross-sectional view showing a schematic structure of a pixel array of an image sensor according to another embodiment.
Figure 38 is a block diagram schematically showing an electronic device including an image sensor according to embodiments.
FIG. 39 is a block diagram schematically showing the camera module shown in FIG. 38.
Figures 40 to 49 show various examples of electronic devices to which image sensors are applied according to embodiments.

Hereinafter, an image sensor having a color separation lens array and an electronic device including the same will be described in detail with reference to the attached drawings. The described embodiments are merely illustrative, and various modifications are possible from these embodiments. In the following drawings, the same reference numerals refer to the same components, and the size of each component in the drawings may be exaggerated for clarity and convenience of explanation.

Hereinafter, the expressions described as “above” or “above” may include not only those directly above/below/left/right in contact, but also those above/below/left/right without contact.

Terms such as first, second, etc. may be used to describe various components, but are used only for the purpose of distinguishing one component from another component. These terms do not limit the difference in material or structure of the constituent elements.

Singular expressions include plural expressions unless the context clearly dictates otherwise. Additionally, when a part "includes" a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

In addition, terms such as "... unit" and "module" used in the specification refer to a unit that processes functions or operations, which may be implemented as hardware or software, or as a combination of hardware and software.

The use of the term “above” and similar referential terms may refer to both the singular and the plural.

The steps comprising the method may be performed in any suitable order unless explicitly stated that they must be performed in the order described. In addition, the use of all exemplary terms (e.g., etc.) is simply for explaining the technical idea in detail, and unless limited by the claims, the scope of rights is not limited by these terms.

1 is a block diagram of an image sensor according to an embodiment. Referring to FIG. 1 , the image sensor 1000 may include a pixel array 1100, a timing controller 1010, a row decoder 1020, and an output circuit 1030. The image sensor may be a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor.

The pixel array 1100 includes pixels arranged two-dimensionally along a plurality of rows and columns. The row decoder 1020 selects one of the rows of the pixel array 1100 in response to the row address signal output from the timing controller 1010. The output circuit 1030 outputs a light detection signal in column units from a plurality of pixels arranged along the selected row. To this end, the output circuit 1030 may include a column decoder and an analog to digital converter (ADC). For example, the output circuit 1030 may include a plurality of ADCs arranged for each column between the column decoder and the pixel array 1100 or one ADC arranged at the output terminal of the column decoder. The timing controller 1010, row decoder 1020, and output circuit 1030 may be implemented as one chip or as separate chips. A processor for processing an image signal output through the output circuit 1030 may be implemented as a single chip along with the timing controller 1010, the row decoder 1020, and the output circuit 1030.

The image sensor 1000 may be applied to various optical devices such as camera modules. For example, Figure 2 is a conceptual diagram schematically showing a camera module according to one embodiment.

Referring to FIG. 2, the camera module 1880 according to one embodiment includes a lens assembly 1910 that forms an optical image by focusing light reflected from an object, and converts the optical image formed by the lens assembly 1910 into an electrical image. It may include an image sensor 1000 that converts the signal into a signal, and an image signal processor 1960 that processes the electrical signal output from the image sensor 1000 into an image signal. The camera module 1880 also includes an infrared cut-off filter disposed between the image sensor 1000 and the lens assembly 1910, a display panel for displaying an image formed by the image signal processor 1960, and an image signal processor 1960. It may further include a memory for storing the formed image data. This camera module 1880 can be mounted, for example, in a mobile electronic device such as a cell phone, laptop, tablet PC, etc.

The lens assembly 1910 serves to focus the image of a subject outside the camera module 1880 onto the image sensor 1000, more precisely, onto the pixel array 1100 of the image sensor 1000. In FIG. 2 , a single lens is briefly shown for convenience, but the actual lens assembly 1910 may include a plurality of lenses. When the pixel array 1100 is accurately positioned on the focal plane of the lens assembly 1910, light originating from a point on the subject is re-converged to a point on the pixel array 1100 through the lens assembly 1910. For example, light originating from a point A on the optical axis OX passes through the lens assembly 1910 and then is collected at the center of the pixel array 1100 on the optical axis OX. Light originating from a point (B, C, D) off the optical axis (OX) crosses the optical axis (OX) by the lens assembly (1910) and is concentrated at a point on the periphery of the pixel array (1100). For example, in FIG. 2, light originating from a point B above the optical axis OX is collected at the lower edge of the pixel array 1100 across the optical axis OX, and below the optical axis OX. Light originating from a point (C) crosses the optical axis (OX) and is collected at the upper edge of the pixel array (1100). Additionally, light originating from point D located between the optical axis OX and point B is collected between the center and lower edge of the pixel array 1100.

Therefore, the light departing from different points (A, B, C, D) is oriented at different angles according to the distance between the points (A, B, C, D) and the optical axis (OX). 1100) joined the company. The incident angle of light incident on the pixel array 1100 is typically defined as the chief ray angle (CRA). The chief ray refers to a ray that passes from one point of the subject through the center of the lens assembly 1910 and enters the pixel array 1100, and the chief ray angle refers to the angle that the chief ray makes with the optical axis OX. Light originating from point A on the optical axis OX has a principal ray angle of 0 degrees and is incident perpendicularly to the pixel array 1100. As the starting point moves away from the optical axis (OX), the chief ray angle increases.

From the perspective of the image sensor 1000, the principal ray angle of light incident on the center of the pixel array 1100 is 0 degrees, and the angle of the principal ray of incident light increases toward the edge of the pixel array 1100. For example, the principal ray angle of the light starting from point B and point C and incident on the edge of the pixel array 1100 is the largest, and the principal ray angle of the light starting from point A and incident on the center of the pixel array 1100 is the largest. The principal ray angle of light is 0 degrees. Additionally, the chief ray angle of light starting from point D and incident between the center and edge of the pixel array 1100 is smaller than the chief ray angle of light starting from point B and point C and is greater than 0 degrees.

Accordingly, the principal ray angle of the incident light incident on the pixels varies depending on the positions of the pixels within the pixel array 1100. In particular, the angle of the main ray gradually increases from the center to the edge of the pixel array 1100. If the main ray angle of the incident light incident on the pixels increases, the sensitivity of the pixels may decrease. According to an embodiment, in order to prevent or minimize a decrease in the sensitivity of pixels located at the edge of the pixel array 1100, a planar nano-optical microlens array may be disposed on the pixel array 1100 of the image sensor 1000. You can.

Figure 3 is a cross-sectional view showing a pixel array of an image sensor according to an embodiment. Referring to FIG. 3, the pixel array 1100 of the image sensor 1000 includes a sensor substrate 110, a color filter layer 140 disposed on the sensor substrate 110, and a planar nano-optic layer disposed on the color filter layer 140. It may include a microlens array 150. The planar nano-optical microlens array 150 may include a plurality of planar nano-optical microlenses 151. As exemplarily shown in FIG. 3, the chief ray CR0 incident on the center 1100C of the pixel array 1100 is incident on the pixel array 1100 at an angle perpendicular to or nearly perpendicular to the pixel array 1100. ) The chief rays CR1 and CR2 incident on the peripheral portion 1100P may be incident on the pixel array 1100 at an angle. Therefore, the plurality of planar nano-optical microlenses 151 disposed at the center (1100C) of the pixel array 1100 and the plurality of planar nano-optical microlenses 151 at the periphery (1100P) of the pixel array 1100 emit the main light ( They can be designed differently considering the angle of incidence of CR0, CR1, and CR2).

FIG. 4A is a schematic cross-sectional view of the center of the pixel array of the image sensor shown in FIG. 3. Referring to FIGS. 3 and 4A , the sensor substrate 110 may include a plurality of light sensing cells 111, 112, and 113 that sense light. For example, the sensor substrate 110 may include a first photo-sensing cell 111, a second photo-sensing cell 112, and a third photo-sensing cell 113 that convert light into an electrical signal. In FIG. 4A, for convenience, the first photo-sensing cell 111, the second photo-sensing cell 112, and the third photo-sensing cell 113 are shown sequentially arranged along the horizontal direction, but the present invention is not limited thereto. The plurality of photo-sensing cells 111, 112, and 113 of the sensor substrate 110 may be two-dimensionally arranged in various ways.

The color filter layer 140 may include a plurality of color filters 141, 142, and 143 that transmit only light in a specific wavelength band and absorb or reflect light in wavelength bands other than the specific wavelength band. For example, the color filter layer 140 is disposed on the first photo-sensing cell 111 and transmits only light in the first wavelength band, and is disposed on the second photo-sensing cell 112 to transmit only light in the first wavelength band. A second color filter 142 that transmits only light in a second wavelength band different from the first wavelength band, and is disposed on the third photo-sensing cell 113 to transmit only light in a third wavelength band different from the first and second wavelength bands. It may include a third color filter 143 that transmits light. In FIG. 4A , for convenience, the first color filter 141, the second color filter 142, and the third color filter 143 are shown as being sequentially arranged along the horizontal direction, but the display is not limited thereto. The plurality of color filters 141, 142, and 143 of the color filter layer 140 may be two-dimensionally arranged in various ways.

The planar nano-optical microlens array 150 disposed on the color filter layer 140 may include a plurality of planar nano-optical microlenses 151 arranged in two dimensions. The plurality of planar nano-optical microlenses 151 can correspond one-to-one with the plurality of color filters 141, 142, and 143, and can also correspond one-to-one with the plurality of photo-sensing cells 111, 112, and 113. Each of the plurality of planar nano-optical microlenses 151 may be configured to focus light on a corresponding light-sensing cell among the plurality of light-sensing cells 111, 112, and 113. To this end, the plurality of planar nano-optical microlenses 151 may have a nano-pattern structure capable of concentrating light.

FIG. 5 is a plan view exemplarily showing the shape of the planar nano-optical microlens 151 shown in FIG. 4A. Referring to FIG. 5, the planar nano-optical microlens 151 may include a high refractive index nanostructure 151H and a low refractive index structure 151L filled between the high refractive index nanostructures 151H. For example, the planar nano optical microlens 151 may include one low refractive index nanostructure 151L in the form of a plate and a plurality of high refractive index structures 151H in the shape of holes. The high refractive index nanostructure (151H) may be made of a dielectric material with a relatively high refractive index and low absorption in the visible light band, such as TiO ₂ , GaN, SiN ₃ , ZnS, ZnSe, Si ₃ N ₄ , etc., and may be a low refractive index structure ( 151L) may be made of a dielectric material that has a relatively low refractive index and low absorption rate in the visible light band, such as SiO ₂ , siloxane-based spin on glass (SOG), air, etc. For example, the refractive index of the high refractive index nanostructure (151H) may be about 2.0 or more for light with a wavelength of about 630 nm, and the refractive index of the low refractive index structure (151L) may be about 1.0 or more and less than 2.0 for light with a wavelength of about 630 nm. You can. Additionally, the difference between the refractive index of the high refractive index nanostructure 151H and the refractive index of the low refractive index structure 151L may be about 0.5 or more.

In order for the planar nano-optical microlens 151 to function as a convex lens that converges light, the effective refractive index of the planar nano-optical microlens 151 is highest in one region of the planar nano-optical microlens 151 and is It may gradually decrease towards the periphery of the area. Here, the effective refractive index may correspond to the ratio of the high refractive index nanostructure 151H to the low refractive index structure 151L within each planar nano-optical microlens 151. In other words, the ratio of the high refractive index nanostructure 151H to the low refractive index structure 151L may be highest in one region of the planar nano-optical microlens 151 and gradually decrease toward the periphery of that region. Hereinafter, the region with the highest effective refractive index within the planar nano-optical microlens 151 is referred to as the “refractive index peak region.” To satisfy these conditions, the width or pitch of the low refractive index structure 151L and the high refractive index nanostructure 151H may be selected to be different in and around the refractive index peak area of the planar nano-optical microlens 151. For example, within the planar nano-optical microlens 151, a plurality of high refractive index nanostructures 151H having a nanopost shape may be two-dimensionally arranged, and the width of the plurality of high refractive index nanostructures 151H may be Alternatively, the diameter may be largest at the peak area of the refractive index and gradually become smaller toward the periphery. In other words, the high refractive index nanostructure 151H with the largest width or diameter in the planar nano-optical microlens 151 disposed at the center (1100C) of the pixel array 1100 is the innermost of the planar nano-optical microlens 151. can be placed in As the distance from the center of the planar nano-optical microlens 151 increases, the width or diameter of the high refractive index nanostructure 151H may gradually decrease.

In addition, the planar nano-optical microlens 151 may serve to change the angle of incidence of incident light so that light is incident almost vertically at the center of the corresponding photo-sensing cell. As described above, the angle of the main ray of incident light varies depending on the position on the pixel array 1100. Accordingly, the position of the refractive index peak area within the planar nano-optical microlens 151 may vary depending on the position of the planar nano-optical microlens 151 within the pixel array 1100.

When the planar nano-optical microlens 151 is placed in the center (1100C) of the pixel array 1100 where the incident light (Li) is incident almost vertically, the planar nano-optical microlens 151 changes the angle at which the light travels. There is no need to change. Therefore, as shown in FIG. 4A, the refractive index peak area of the planar nano-optical microlens 151 disposed at the center 1100C of the pixel array 1100 may be located at the center of the planar nano-optical microlens 151. there is.

FIG. 6 is a plan view exemplarily showing the effective refractive index distribution of the planar nano-optical microlens 151 shown in FIG. 4A. Referring to FIG. 6, the planar nano-optical microlens 151 disposed at the center 1100C of the pixel array 1100 has a first region 151a disposed at the center and a first region 151a adjacent to the first region 151a. A second area 151b surrounding the area 151a, a third area 151c adjacent to the second area 151b and surrounding the second area 151b, and a third area 151c adjacent to the third area 151c. It may include a fourth area 151d surrounding the area 151c, and a fifth area 151e adjacent to the fourth area 151d and surrounding the fourth area 151d. The first to fifth regions 151a to 151e may be arranged in a concentric circle with the center of the planar nano-optical microlens 151 as the origin.

The first area 151a located in the very center is an area with the largest effective refractive index. In other words, the ratio of the high refractive index nanostructure 151H to the low refractive index structure 151L is the largest in the first region 151a. The planar nano-optical microlens 151 may have an effective refractive index distribution in which the effective refractive index gradually decreases from the first region 151a to the fifth region 151e. The effective refractive index of the second area 151b is lower than the effective refractive index of the first area 151a, the effective refractive index of the third area 151c is lower than the effective refractive index of the second area 151b, and the effective refractive index of the fourth area 151d is lower than that of the second area 151b. ) is lower than the effective refractive index of the third region 151c. And, the effective refractive index of the fifth region 151e is the lowest. To this end, at least one of the width and pitch of the low refractive index structure 151L and the high refractive index nanostructure 151H in the first region 151a to the fifth region 151e may be selected differently. In FIG. 6, the planar nano-optical microlens 151 is exemplarily shown as including regions having five different effective refractive indices, but is not necessarily limited thereto. The number of regions with different effective refractive indices within one planar nano-optical microlens 151 may be selected in various ways depending on design conditions.

In this structure, the planar nano-optical microlens 151 may have a symmetrical effective refractive index distribution with respect to the center of the planar nano-optical microlens 151. Additionally, the peak region of the refractive index of the planar nano-optical microlens 151 is located at the center of the planar nano-optical microlens 151, particularly the first region 151a. In FIG. 6, the planar nano-optical microlens 151 is illustrated as having five concentric circles, but it is not necessarily limited thereto. For example, the number of concentric circles may be selected differently depending on the size of the planar nano-optical microlens 151, the effective refractive index distribution profile required for the planar nano-optical microlens 151, etc.

FIG. 4B exemplarily shows a convex microlens equivalent to the planar nano-optical microlens 151 shown in FIG. 4A. When the planar nano-optical microlens 151 shown in FIG. 4A has the effective refractive index distribution shown in FIG. 6, the optical axis located at the center of the equivalent convex microlens is connected to the light sensing cell and color filter corresponding to the convex microlens. The same optical effect can be obtained as matching the center of . Additionally, the equivalent convex microlens may have a lens surface that is symmetrical around the optical axis. In this case, light incident perpendicularly to the pixel array 1100 may pass through the planar nano-optical microlens 151 and the color filter layer 140 and then incident perpendicularly to the sensor substrate 110. Therefore, at the center of the pixel array 1100, the refractive index peak area may be located at the center of the planar nano-optical microlens 151, and the planar nano-optical microlens 151 may be located at the center of the corresponding photo-sensing cell and color filter. The refractive index peak areas may be arranged to coincide.

Meanwhile, FIG. 7A is a schematic cross-sectional view of the periphery of the pixel array of the image sensor. Referring to FIGS. 3 and 7A , incident light Li may be incident at an angle on the peripheral portion 1100P of the pixel array 1100. For example, incident light Li may enter the peripheral portion 1100P on the right side of the pixel array 1100 at an angle from left to right. In particular, the incident light (Li) may be incident at an angle to the planar nano-optical microlens 151 disposed at the periphery of the planar nano-optical microlens array 150. Accordingly, the planar nano-optical microlens 151 disposed at the peripheral portion 1100P of the pixel array 1100 may be configured to change the direction of travel of obliquely incident light closer to the vertical direction. To this end, the nanostructures in the planar nano-optical microlens 151 disposed at the periphery 1100P of the pixel array 1100 may be arranged in an asymmetric distribution.

FIG. 7B is a plan view illustrating the shape of the planar nano-optical microlens shown in FIG. 7A. Referring to FIG. 7B, the width or diameter of the plurality of high refractive index nanostructures 151H within each planar nano-optical microlens 151 may be asymmetrically distributed considering the chief ray angle. For example, the high refractive index nanostructure 151H, which has the largest width or diameter within each planar nano-optical microlens 151, is located at the center 1100C of the pixel array 1100 from the center of the planar nano-optical microlens 151. ) can be located off toward. In other words, the high refractive index nanostructure 151H, which has the largest width or diameter within the planar nano-optical microlens 151, may be disposed biased toward the center 1100C of the pixel array 1100. Since the main ray angle increases as it moves away from the center (1100C) of the pixel array 1100, a plurality of high refractive index nanostructures in the planar nano-optical microlens 151 ( The width or diameter of 151H) may be distributed more asymmetrically. For example, the farther the planar nano-optical microlens 151 is disposed from the center 1100C of the pixel array 1100, the higher the refractive index nanostructure (with the largest width or diameter) within the planar nano-optical microlens 151. The distance between the position of 151H) and the center of the planar nano-optical microlens 151 may become larger.

FIG. 8A is a plan view exemplarily showing the effective refractive index distribution of the planar nano-optical microlens shown in FIG. 7A. Referring to FIG. 8A, the planar nano-optical microlens 151 disposed at the peripheral portion 1100P of the pixel array 1100 includes a first region 151a disposed away from the center of the planar nano-optical microlens 151, A second area 151b adjacent to the first area 151a and surrounding the first area 151a, a third area 151c adjacent to the second area 151b and surrounding the second area 151b, 3 A fourth area 151d adjacent to the third area 151c and surrounding the third area 151c, and a fifth area 151e adjacent to the fourth area 151d and surrounding the fourth area 151d. It can be included. The first area 151a is a refractive index peak area with the highest effective refractive index. In other words, the ratio of the high refractive index nanostructure 151H to the low refractive index structure 151L is the largest in the first region 151a. The effective refractive index may gradually decrease from the first area 151a to the fifth area 151e. Accordingly, the effective refractive index distribution within each planar nano-optical microlens 151 disposed in the peripheral portion 1100P of the pixel array 1100 may be asymmetric. A plurality of high refractive index nanostructures 151H within each planar nano-optical microlens 151 may be designed so that each planar nano-optical microlens 151 implements an effective refractive index distribution as shown in FIG. 8A. .

For example, the high refractive index nanostructure 151H having the largest width or diameter may be disposed in the first region 151a, which is the refractive index peak region within the planar nano-optical microlens 151. The widths or diameters of the plurality of high refractive index nanostructures 151H within each planar nano-optical microlens 151 are the first region 151a, the refractive index peak region, or the high refractive index nanostructure having the largest width or diameter ( 151H) may be asymmetrically distributed. For example, referring to Figure 8b, among the two high refractive index nanostructures directly adjacent to the high refractive index nanostructure 151H (hereinafter, "peak high refractive index nanostructure 151Hp") having the largest width or diameter, the pixel The high refractive index nanostructure 151H closer to the center 1100C of the array 1100 is called the first high refractive index nanostructure 151Ha, and the high refractive index nanostructure 151H farther from the center 1100C of the pixel array 1100 is called the first high refractive index nanostructure 151Ha. ) is the second high refractive index nanostructure (151Hb), the first pitch (Pa) between the peak high refractive index nanostructure (151Hp) and the first high refractive index nanostructure (151Ha) is the peak high refractive index nanostructure (151Hp) and the second pitch (Pb) between the high refractive index nanostructure (151Hb), and the width or diameter (Wa) of the first high refractive index nanostructure (151Ha) is the width or diameter of the second high refractive index nanostructure (151Hb) It may be different from the diameter (Wb). For example, the width or diameter (Wa) of the first high refractive index nanostructure (151Ha) may be smaller than the width or diameter (Wb) of the second high refractive index nanostructure (151Hb). .

According to another embodiment, as shown in Figure 8c, the width or diameter (Wa) of the first high refractive index nanostructure (151Ha) may be the same as the width or diameter (Wb) of the second high refractive index nanostructure (151Hb). May be, the first pitch (Pa) between the peak high refractive index nanostructure (151Hp) having the largest width or diameter and the first high refractive index nanostructure (151Ha) is the peak high refractive index nanostructure (151Hp) having the largest width or diameter. It may be different from the second pitch (Pb) between 151Hp) and the second high refractive index nanostructure (151Hb). For example, the first pitch (Pa) may be smaller than the second pitch (Pb). Here, the expression "the width or diameter (Wa) of the first high refractive index nanostructure (151Ha) is the same as the width or diameter (Wb) of the second high refractive index nanostructure (151Hb)" means that the first high refractive index nanostructure (151Ha) ) does not necessarily mean that the width or diameter (Wa) of the second high refractive index nanostructure (151Hb) perfectly matches the width or diameter (Wb) of the second high refractive index nanostructure (151Hb). For example, the first high refractive index nanostructure (151Ha) and the first high refractive index nanostructure (151Ha) so that the width or diameter (Wb) of the second high refractive index nanostructure (151Ha) is the same Although the second high refractive index nanostructure 151Hb can be designed, the width or diameter (Wb) of the first high refractive index nanostructure (151Ha) and the width or diameter (Wb) of the second high refractive index nanostructure (151Hb) are It may vary slightly within tolerances in the manufacturing process. Additionally, the phase profile of the planar nano-optical microlens 151 shown in FIG. 8C may be mainly determined by the width or diameter of the high refractive index nanostructures 151H, and the phase profile of the planar nano-optical microlens 151 shown in FIG. 8C may be determined primarily by the width or diameter of the high refractive index nanostructures 151H. ), the slope or change in the effective refractive index distribution may be mainly determined by the pitches between the high refractive index nanostructures 151H.

Additionally, referring again to FIG. 8A, the first region 151a, which is the peak region of the refractive index, within the planar nano-optical microlens 151 may be disposed to be biased toward the center 1100C of the pixel array 1100. As the planar nano-optical microlens 151 is placed further away from the center 1100C of the pixel array 1100, the peak area of the refractive index within the planar nano-optical microlens 151 moves toward the center 1100C of the pixel array 1100. It may be placed more biased. In other words, the farther the planar nano-optical microlens 151 is placed from the center (1100C) of the pixel array 1100, the location of the refractive index peak area within the planar nano-optical microlens 151 and the planar nano-optical microlens ( 151), the distance between the centers may become larger. In addition, the first area 151a is formed so that the center of the first area 151a is closest to the center of the pixel array 1100 and the distance from the center of the pixel array 1100 to the center of the fifth area 151e is the largest. The center of each of the to fifth regions 151e may be shifted.

FIG. 9 is an exemplary cross-sectional view showing the effective refractive index distribution of the planar nano-optical microlens shown in FIG. 7A. The curve displayed on the color filter layer 140 in FIG. 9 represents the effective refractive index distribution of each planar nano-optical microlens 151. Alternatively, the curve displayed on the color filter layer 140 may represent the phase profile of light immediately after passing through each planar nano-optical microlens 151. Therefore, the height of the curve displayed on the color filter layer 140 in FIG. 9 can be interpreted as a normalized value of the effective refractive index within each planar nano-optical microlens 151 or a normalized value of the phase of transmitted light.

Referring to FIG. 9, the refractive index peak (C1) (or phase peak) in the planar nano-optical microlens 151 disposed at the periphery (1100P) of the pixel array 1100 is the center of the planar nano-optical microlens 151. It may be located away from (C0) toward the center 1100C of the pixel array 1100. Therefore, the distance between the first edge (left) of the planar nano-optic microlens 151 on the side close to the center 1100C of the pixel array 1100 and the refractive index peak C1 is the plane nano-optics opposite the first edge. It may be smaller than the distance between the second edge (right) of the microlens 151 and the refractive index peak (C1).

Meanwhile, in FIG. 9, the effective refractive index distribution is shown as a continuous and smooth curve for convenience, but the effective refractive index distribution may have a step shape that increases/decreases discontinuously. In this case, the refractive index peak C1 may be expressed as one area rather than one point. In this respect, the refractive index peak C1 may have the same meaning as the previously mentioned refractive index peak area.

Also, referring to FIG. 9 , the effective refractive index distribution or the phase distribution of transmitted light in each planar nano-optical microlens 151 disposed in the peripheral portion 1100P of the pixel array 1100 may have an asymmetric form. In other words, the effective refractive index distribution on both sides may be different based on the refractive index peak (C1). For example, based on the refractive index peak (C1), the effective refractive index of the direction in which light is incident or closer to the center (1100C) of the pixel array 1100 (or the area between the first edge and the refractive index peak (C1)) The slope or change amount of the distribution may be greater than the slope or change amount of the effective refractive index distribution on the side away from the center 1100C of the pixel array 1100 (or the area between the second edge and the refractive index peak C1). In other words, based on the refractive index peak (C1), the effective refractive index distribution in the direction in which light is incident or close to the center (1100C) of the pixel array 1100 (or the area between the first edge and the refractive index peak (C1)) The slope or change amount is relatively sharp, and the slope or change amount of the effective refractive index distribution on the side away from the center (1100C) of the pixel array 1100 (or the area between the second edge and the refractive index peak (C1)) is relatively gentle. can do. For example, the inclination or inclination angle ( θ1) may be greater than the slope or tilt angle θ2 of the second line segment S2 extending between the effective refractive index value of the second edge and the refractive index peak C1.

As the distance from the center (1100C) of the pixel array 1100 increases, the distance between the center (C0) of the planar nano-optical microlens 151 and the refractive index peak (C1) increases, and the effective refractive index distribution or the phase distribution of transmitted light increases. Asymmetry may increase. For example, the second distance (d2) between the center (C0) of the planar nano-optics microlens 151 disposed in the middle in FIG. 9 and the refractive index peak (C1) is It is greater than the first distance (d1) between the center (C0) of the microlens 151 and the refractive index peak (C1), and the center (C0) and refractive index of the planar nano-optical microlens 151 disposed on the rightmost side in FIG. 9 The third distance d3 between the peaks C1 is greater than the second distance d2. In FIG. 9 , the planar nano-optical microlens 151 disposed in the middle is disposed farther from the center 1100C of the pixel array 1100 than the planar nano-optical microlens 151 disposed on the leftmost side, and in FIG. 9 The planar nano-optical microlens 151 disposed on the far right is located farther from the center 1100C of the pixel array 1100 than the planar nano-optical microlens 151 disposed in the middle.

And, in FIG. 9, the slope or tilt angle θ3 of the third line segment S3 extending between the effective refractive index value of the first edge of the planar nano-optical microlens 151 disposed in the middle and the refractive index peak C1 is It is greater than the inclination or inclination angle (θ1) of the first line segment (S1) and extends between the effective refractive index value of the first edge of the planar nano-optical microlens 151 disposed on the rightmost side in FIG. 9 and the refractive index peak (C1). The slope or slope angle θ5 of one fifth line segment S5 is greater than the slope or slope angle θ3 of the third line segment S3. Accordingly, the slope of the effective refractive index distribution in the area between the first edge and the refractive index peak C1 may increase as the distance from the center 1100C of the pixel array 1100 increases. In addition, in FIG. 9, the slope or tilt angle θ4 of the fourth line segment S4 extending between the effective refractive index value of the second edge of the planar nano-optical microlens 151 disposed in the middle and the refractive index peak C1 is It is smaller than the inclination or inclination angle (θ2) of the second line segment (S2) and extends between the effective refractive index value of the second edge of the planar nano-optical microlens 151 disposed on the rightmost side in FIG. 9 and the refractive index peak (C1). The slope or slope angle θ6 of one sixth line segment S6 is smaller than the slope or slope angle θ4 of the fourth line segment S4. Accordingly, as the distance from the center 1100C of the pixel array 1100 increases, the slope of the effective refractive index distribution in the area between the second edge and the refractive index peak C1 may decrease.

All of the planar nano-optical microlenses 151 in the planar nano-optical microlens array 150 may have different effective refractive index distributions depending on the distance from the center 1100C of the pixel array 1100. In this case, the effective refractive index distribution of the planar nano-optical microlenses 151 may change almost continuously as the distance from the center 1100C of the pixel array 1100 increases. Alternatively, the planar nano-optical microlens array 150 may be divided into a plurality of zones, and the planar nano-optical microlenses 151 disposed in the same zone may have the same effective refractive index distribution. In this case, the effective refractive index distribution of the planar nano-optical microlenses 151 may change discontinuously in two different regions.

For example, Figure 10 is a plan view schematically showing a plurality of regions of a nano-optical microlens array according to one embodiment. Referring to FIG. 10, the planar nano-optical microlens array 150 includes a first zone 150A at the center, a second zone 150B surrounding the first zone 150A, and a second zone 150B. It may include a surrounding third zone 150C. The first area 150A may correspond to the center 1100C of the pixel array 1100. For example, an area where the principal ray angle (CRA) of incident light is within about 10° may be defined as the center 1100C of the pixel array 1100. Accordingly, the center 1100C of the pixel array 1100 may include not only an area where the principal ray angle (CRA) is strictly 0°, but also an area where the principal ray angle (CRA) is slightly greater than 0° within a predetermined range. In this case, all of the planar nano-optical microlenses 151 disposed in the first area 150A may have a symmetrical effective refractive index distribution.

The principal ray angle (CRA) of the incident light in the second zone 150B may be, for example, greater than about 10° and within about 20°. All of the planar nano-optical microlenses 151 disposed in the second zone 150B may have the same asymmetric effective refractive index distribution. Additionally, the principal ray angle (CRA) of the incident light in the third zone 150C may be greater than, for example, about 20°. The planar nano-optical microlenses 151 disposed in the third zone 150C all have the same asymmetric effective refractive index distribution, and the effective refractive index distribution of the planar nano-optical microlens 151 disposed in the third zone 150C The degree of asymmetry may be greater than the degree of asymmetry of the planar nano-optical microlens 151 disposed in the second area 150B. In FIG. 10, the planar nano-optical microlens array 150 is shown divided into three zones, but this is only an example to aid understanding and the number of zones is not limited to three. In addition, the range of the principal ray angle (CRA) of incident light, which serves as a standard for dividing a plurality of zones, can also be selected in various ways in consideration of the size and sensitivity of the image sensor 1000, the optical characteristics of the lens assembly 1910, etc. .

Since the above-described planar nano-optical microlens array 150 has a planar nanostructure, the optical curvature profile of the lens surface can be more easily determined compared to a microlens array with a curved surface. For example, within each planar nano-optical microlens 151, the diameter, width, pitch, etc. of the low refractive index structure 151L and the high refractive index nanostructure 151H are measured in areas within the planar nano-optical microlens 151. By making different selections, a planar nano-optical microlens 151 having a desired effective refractive index distribution can be easily designed. Therefore, it is possible to easily design and manufacture a planar nano-optical microlens 151 having an optimal shape according to the main ray angle of the incident light incident on the pixel array 1100 of the image sensor. Additionally, as described above, the planar nano-optical microlens array 150 can change the angle of incidence of incident light incident at a large chief ray angle at the peripheral portion 1100P of the pixel array 1100 of the image sensor to be closer to vertical. In particular, the planar nano-optical microlens array 150 may be provided with various types of planar nano-optical microlenses 151 in consideration of changes in the angle of the chief ray according to various positions on the pixel array 1100 of the image sensor. Accordingly, the sensitivity of pixels located in the peripheral periphery 1100P of the pixel array 1100 of the image sensor can be improved to be similar to the sensitivity of pixels located in the center 1100C of the pixel array 1100.

In FIG. 5 , high refractive index nanostructures 151H in the form of nanoposts are illustrated as arranged at regular lattice points along rows and columns, but the present invention is not necessarily limited thereto. For example, FIGS. 11A to 11D are plan views illustrating various shapes of planar nano-optical microlenses 151.

Referring to FIG. 11A, the planar nano optical microlens 151 may include a plurality of high refractive index nanostructures 151H having a nanopost shape arranged radially. In this case, the proportion of the plurality of high refractive index nanostructures 151H is highest in the refractive index peak area of the planar nano optical microlens 151, and the proportion of the plurality of high refractive index nanostructures 151H increases as the distance from the refractive index peak area increases. It can be lowered. For example, the specific gravity of the plurality of high refractive index nanostructures 151H may be defined as the ratio of the area occupied by the plurality of high refractive index nanostructures 151H to unit area. In FIG. 11A, the plurality of high refractive index nanostructures 151H are illustrated as circular, but the plurality of high refractive index nanostructures 151H may have an oval or polygonal shape. In addition, in Figure 11a, the dimensions (i.e., width or diameter) of the plurality of high refractive index nanostructures 151H are large in the refractive index peak region, and the dimensions of the plurality of high refractive index nanostructures 151H become smaller as they move to the periphery. It is not necessarily limited to this. For example, the dimensions of the plurality of high refractive index nanostructures 151H may be the same, and the density of the plurality of high refractive index nanostructures 151H may decrease from the refractive index peak region to the periphery.

Referring to FIG. 11B, the planar nano optical microlens 151 may include a plurality of high refractive index nanostructures 151H having a ring shape and a plurality of low refractive index structures 151L having a ring shape. A plurality of high refractive index nanostructures 151H and a plurality of low refractive index structures 151L may be alternately arranged in a concentric circle shape centered on a refractive index peak region. A circular high-refractive-index nanostructure 151H may be placed at the innermost part of the planar nano-optical microlens 151. The diametric width of the high refractive index nanostructure 151H may be largest at the refractive index peak region, and as the distance from the center of the planar nano-optical microlens 151 increases, the diametric width of the high refractive index nanostructure 151H gradually becomes smaller. You can.

Additionally, referring to FIG. 11C, the planar nano-optical microlens 151 may include a plurality of high refractive index nanostructures 151H divided along the circumferential direction. Each high refractive index nanostructure 151H may have an arc shape. In this case as well, the proportion of the high refractive index nanostructure (151H) can be designed to be high in the refractive index peak area of the planar nano optical microlens 151, and the proportion of the high refractive index nanostructure (151H) can be designed to be low as the distance from the refractive index peak area increases. You can.

In addition, referring to FIG. 11D, the planar nano-optical microlens 151 may include one high refractive index nanostructure 151H in the form of a plate and a plurality of low refractive index structures 151L in the form of holes. . To this end, the high refractive index nanostructure 151H may be etched to form a plurality of holes, and the holes may be filled with a low refractive index material. Or, the hole may not be filled with anything. In this case, the low refractive index structure 151L may be made of air. The diameters of all holes in the planar nano-optical microlens 151 may be the same, but the diameter of the holes may increase as the distance from the peak region of the refractive index increases. In the refractive index peak area, the number of holes is small and/or the diameter of the hole is small so that the specific gravity of the high refractive index nanostructure 151H is high, and the holes are formed so that the specific gravity of the high refractive index nanostructure 151H decreases as the distance from the refractive index peak area increases. The number and/or diameter of holes may be increased.

12A and 12B are cross-sectional views exemplarily showing the shape of a planar nano-optical microlens according to another embodiment. As shown in FIGS. 12A and 12B, the planar nano-optical microlens 151 may have a multi-layer structure. For example, the planar nano-optical microlens 151 may include a first layer (L1) and a second layer (L2) stacked on the first layer (L1). The first layer (L1) and the second layer (L2) include a high refractive index nanostructure (151H) and a low refractive index structure (151L), respectively, and the high refractive index nanostructure (151H) and the low refractive index structure of the first layer (L1) The pattern of the structure 151L may be different from the pattern of the high refractive index nanostructure 151H and the low refractive index structure 151L of the second layer L2. The effective refractive index of each region of the planar nano-optical microlens 151 having a multi-layer structure is the high refractive index nanostructure 151H in the first layer (L1) and the second layer (L2), the first layer (L1), and the second layer (L2). It can be determined by combining the low refractive index structure 151L in the layer L2.

Referring to FIG. 12A, the planar nano-optical microlens 151 disposed at the center 1100C of the pixel array 1100 where the incident light Li is vertically incident is formed on the first layer L1 and the second layer L2. All of these may have a symmetrical shape with respect to the center of the planar nano-optical microlens 151. At the center of the planar nano-optical microlens 151, the high refractive index nanostructures 151H in the first layer L1 and the second layer L2 have the same width, but at the periphery, the second layer ( The width of the high refractive index nanostructure 151H of L2) may be smaller than the width of the high refractive index nanostructure 151H of the first layer L1 disposed below it. In addition, the effective refractive index of the planar nano-optical microlens 151 considered by combining the first layer (L1) and the second layer (L2) is highest near the center of the planar nano-optical microlens 151 and is highest around the refractive index peak area. It may gradually decrease as time goes by.

Also, referring to FIG. 12b, the planar nano-optical microlens 151 disposed on the periphery 1100P of the pixel array 1100 where the incident light Li is obliquely incident is formed on the first layer L1 and the second layer L2. All of these may have an asymmetric shape based on the center of the planar nano-optical microlens 151. For example, the refractive index peak area of the planar nano-optical microlens 151 is angled from the center of the planar nano-optical microlens 151 toward the direction in which light is incident or towards the center of the center 1100C of the pixel array 1100. It may be located biased. The effective refractive index of the planar nano-optical microlens 151 considering the first layer (L1) and the second layer (L2) comprehensively is highest in the refractive index peak area and may gradually decrease toward the periphery of the refractive index peak area. In addition, in the refractive index peak area of the planar nano optical microlens 151, the high refractive index nanostructures 151H in the first layer (L1) and the second layer (L2) have the same width, but in the area away from the refractive index peak area, The width of the high refractive index nanostructure 151H of the second layer (L2) may be smaller than the width of the high refractive index nanostructure 151H of the first layer (L1) disposed below.

In the above example, boundaries between the corresponding light sensing cells, color filters, and planar nano-optical microlenses 151 may coincide with each other in the entire area of the pixel array 1100. In other words, in the entire area of the pixel array 1100, the corresponding light sensing cells, color filters, and planar nano-optical microlenses 151 may be aligned to face each other in the vertical direction. However, it is not necessarily limited to this, and the color filter and the planar nano-optical microlens 151 at the peripheral portion 1100P of the pixel array 1100 may be shifted in the direction in which light is incident.

For example, FIG. 13 is a plan view showing a pixel array of an image sensor according to another embodiment, and FIG. 14 is a schematic cross-sectional view along line A-A' of the periphery of the pixel array of the image sensor shown in FIG. 13. Referring to FIGS. 13 and 14 , the planar nano-optical microlens 151 may be shifted and disposed at the periphery of the pixel array 1100 toward the direction in which light is incident. In other words, the planar nano-optical microlens 151 disposed at the periphery of the pixel array 1100 may be shifted toward the center of the pixel array 1100. For example, the planar nano-optical microlens 151 disposed on the right side of the pixel array 1100 may be shifted to the left, and the planar nano-optical microlens 151 disposed on the left side of the pixel array 1100 may be shifted to the right. can be shifted to . Accordingly, the boundary between the planar nano-optical microlenses 151 disposed at the periphery of the pixel array 1100 may not coincide with the boundary between the corresponding photo-sensing cells and the boundary between the color filters. In this case as well, the refractive index peak area within the planar nano-optical microlens 151 disposed at the periphery of the pixel array 1100 is, as described above, the pixel array 1100 from the center of the planar nano-optical microlens 151. It can be located away from the center of.

Additionally, like the planar nano-optical microlens 151, the color filters 141, 142, and 143 disposed at the periphery of the pixel array 1100 may be shifted toward the center of the pixel array 1100. For example, the color filters 141, 142, and 143 disposed on the right side of the pixel array 1100 may be shifted to the left, and the color filters 141, 142, and 143 disposed on the left side of the pixel array 1100. ) can be shifted to the right. The distance at which the color filters 141, 142, and 143 are shifted may be smaller than the distance at which the corresponding planar nano-optical microlens 151 is shifted. Accordingly, the color filters 141, 142, and 143 may protrude in a horizontal direction toward the center of the pixel array 1100 with respect to the corresponding light sensing cells 111, 112, and 113, and the planar nano-optical microlens 151 ) may protrude in the horizontal direction toward the center of the pixel array 1100 with respect to the corresponding color filters 141, 142, and 143. Then, light incident on the pixel array 1100 at an angle may pass through the planar nano-optical microlens 151 and the color filter layer 140 and enter the sensor substrate 110 approximately perpendicularly. Additionally, the planar nano-optical microlens 151 can focus light toward the approximate center of the corresponding photo-sensing cell.

In this case, the total area of the planar nano-optical microlens array 150 may be smaller than the total area of the pixel array 1100, the total area of the sensor substrate 110, or the total area of the color filter layer 140. Additionally, the total area of the color filter layer 140 may be smaller than the total area of the sensor substrate 110.

The distance at which the planar nano-optical microlens 151 and the color filters 141, 142, and 143 are shifted may be determined by the principal ray angle of the incident light. As the principal ray angle of the incident light increases, the distance at which the planar nano-optical microlens 151 and the color filters 141, 142, and 143 are shifted may increase. Accordingly, as the distance from the center of the pixel array 1100 increases, the distance at which the planar nano-optical microlens 151 and the color filters 141, 142, and 143 are shifted may gradually increase.

Alternatively, similar to what is described in FIG. 10, the pixel array 1100 is divided into a plurality of zones, and the planar nano-optical microlens 151 and color filters 141, 142, and 143 are shifted according to the divided zones. The distance can be changed step by step. In this case, the planar nano-optical microlenses 151 disposed in the same area of the pixel array 1100 may be shifted by the same distance from each other. Additionally, the color filters 141, 142, and 143 disposed in the same area of the pixel array 1100 may be shifted by the same distance from each other.

15 to 17 are cross-sectional views exemplarily showing the shape of a planar nano-optical microlens according to another embodiment further comprising a convex microlens. Referring to FIG. 15 , the pixel array 1100 of the image sensor may further include a convex microlens 161 disposed on the planar nano-optical microlens 151. In Figure 15, only one convex microlens 161 disposed on one planar nano-optical microlens 151 is shown, but a plurality of convex microlenses 161 on a plurality of planar nano-optical microlenses 151 are two-dimensional. can be arranged. The planar nano-optical microlens 151 and the convex microlens 161 may correspond one to one. When additional convex microlenses 161 are used, crosstalk occurring at the interface between the planar nano-optical microlenses 151 can be prevented or reduced.

Referring to FIG. 15 , the refractive index peak areas of the corresponding planar nano-optical microlenses 151 disposed at the center of the pixel array 1100 and the optical axes of the convex microlenses 161 may be aligned to coincide with each other. Additionally, the boundaries of the corresponding planar nano-optical microlenses 151 and the boundaries of the convex microlenses 161 may coincide with each other.

Referring to FIG. 16, the refractive index peak area of the planar nano-optical microlens 151 disposed at the periphery of the pixel array 1100 and the optical axis of the convex microlens 161 may not coincide with each other. Additionally, the convex microlens 161 disposed on the planar nano-optical microlens 151 may be shifted toward the direction in which light is incident on the planar nano-optical microlens 151. For example, at the right edge of the pixel array 1100, the convex microlens 161 is shifted to the left with respect to the corresponding planar nano-optic microlens 151. Accordingly, the convex microlens 161 at the periphery of the pixel array 1100 may be shifted toward the center of the pixel array 1100 with respect to the corresponding planar nano-optic microlens 151.

In FIG. 16 , the refractive index peak area of the planar nano-optical microlens 151 disposed at the periphery of the pixel array 1100 is shown shifted toward the center of the pixel array 1100. However, when an additional convex microlens 161 is used, the refractive index peak area of the planar nano-optical microlens 151 disposed at the periphery of the pixel array 1100 may not shift. Referring to FIG. 17, the convex microlens 161 is shifted toward the center of the pixel array 1100 with respect to the planar nano-optical microlens 151. The planar nano-optical microlens 151 below the convex microlens 161 has an unshifted refractive index peak region. In other words, the peak region of the refractive index of the planar nano-optical microlens 151 is located at the center of the planar nano-optical microlens 151. Even if the refractive index peak area of the planar nano-optical microlens 151 is not shifted, incident light can enter the center of the photo-sensing cell at a relaxed incident angle due to the shifted convex microlens 161.

18 to 21 are cross-sectional views schematically showing a pixel array of an image sensor according to another embodiment. Referring to FIGS. 18 to 21 , the pixel array 1100 of the image sensor may further include a transparent dielectric layer 170 whose thickness increases from the center of the pixel array 1100 toward the periphery.

Referring to FIG. 18, the transparent dielectric layer 170 may be disposed between the sensor substrate 110 and the planar nano-optical microlens array 150, particularly between the color filter layer 140 and the planar nano-optical microlens array 150. there is. The transparent dielectric layer 170 may have an inclined upper surface so that the thickness gradually increases from the center of the pixel array 1100 toward the periphery. In FIG. 18 , the upper surface of the transparent dielectric layer 170 is shown as a flat plate with a constant inclination angle. However, the upper surface of the transparent dielectric layer 170 may be in the form of a curved surface whose inclination angle increases as the angle of the main ray increases. The transparent dielectric layer 170 may be disposed over the entire area of the pixel array 1100, or may be disposed only in a portion of the peripheral area of the pixel array 1100. For example, the transparent dielectric layer 170 may not be disposed in central areas where pixel sensitivity is not significantly reduced due to the chief ray angle.

A plurality of planar nano-optical microlenses 151 may be disposed at an angle on the inclined upper surface of the transparent dielectric layer 170. Since the planar nano-optical microlens 151 is disposed at an angle, the incident angle of incident light incident on the planar nano-optical microlens 151 may be smaller than the chief ray angle. In particular, when the transparent dielectric layer 170 has a curved upper surface whose inclination angle increases as the chief ray angle increases, incident light may enter all the planar nano-optical microlenses 151 at an almost constant angle.

Referring to FIG. 19, a transparent dielectric layer 170 having an inclined upper surface may be disposed on the planar nano-optical microlens array 150. Due to the inclined upper surface of the transparent dielectric layer 170, the incident angle of incident light incident on the upper surface of the transparent dielectric layer 170 at the periphery of the pixel array 1100 may be smaller than the chief ray angle. Additionally, because light is refracted by the transparent dielectric layer 170, the angle of incidence of incident light incident on the planar nano-optical microlenses 151 disposed below the transparent dielectric layer 170 may become smaller.

Referring to FIGS. 20 and 21 , the transparent dielectric layer 170 may have a step shape in which the thickness increases discontinuously from the center of the pixel array 1100 toward the periphery. As shown in FIG. 20, a transparent dielectric layer 170 having a step shape may be disposed between the color filter layer 140 and the planar nano-optical microlens array 150. Additionally, as shown in FIG. 21, the transparent dielectric layer 170 having a step shape may be disposed on the planar nano-optical microlens array 150. Because light is refracted by the transparent dielectric layer 170, the angle of incidence of incident light incident on the planar nano-optical microlens array 150 or the color filter layer 140 may become small. 20 and 21 show that the upper surface of the transparent dielectric layer 170 is parallel to the horizontal plane, but each end of the transparent dielectric layer 170 gradually increases in thickness from the center of the pixel array 1100 toward the periphery. It may have a top surface that is inclined to increase.

Figure 22 is a plan view showing a pixel array of an image sensor according to another embodiment. Referring to FIG. 22, the pixel array 1100 may include a convex microlens array 160 disposed at the center and a planar nano-optical microlens array 150 disposed at the periphery. At the center of the pixel array 1100, where the chief ray angle is small, the planar nano-optical microlens 151 does not exist and only a general convex microlens array 160 can be disposed. For example, only a general convex microlens array 160 may be disposed in an area where the principal ray angle is less than 30 degrees, and a planar nano-optical microlens array 150 may be disposed in an area where the principal ray angle is 30 degrees or more.

FIG. 23 is a cross-sectional view taken along line B-B' showing an example of the pixel array of the image sensor shown in FIG. 22. Referring to FIG. 23, the convex microlens array 160 and the planar nano-optical microlens array 150 may be arranged on the same plane. For example, the convex microlens array 160 including a plurality of convex microlenses 161 and the planar nano-optical microlens array 150 including a plurality of planar nano-optical microlenses 151 are both color filter layers ( 140) can be placed together above.

FIG. 24 is a cross-sectional view taken along line B-B' showing another example of the pixel array of the image sensor shown in FIG. 22. Referring to FIG. 24, the convex microlens array 160 and the planar nano-optical microlens array 150 may be arranged on different planes. For example, a planar nano-optical microlens array 150 may be disposed on the color filter layer 140. In the area within the planar nano-optical microlens array 150 corresponding to the center of the pixel array 1100, the high refractive index nanostructure 151H may not exist and only the low refractive index structure 151L may exist. The convex microlens array 160 may be disposed on the low refractive index structure 151L at the center of the pixel array 1100.

Figure 25 is a schematic cross-sectional view of a pixel array of an image sensor according to another embodiment. Referring to FIG. 25 , the pixel array 1100 may further include a spacer layer 125 disposed between the color filter layer 140 and the planar nano-optical microlens array 150. The spacer layer 125 may include a dielectric material that is transparent to light in the visible light band. Additionally, the spacer layer 125 may include a dielectric material having a lower refractive index than the high refractive index nanostructure 151H. For example, the spacer layer 125 may include the same material as that of the low refractive index structure 151L.

The spacer layer 125 may serve to support the nano optical microlens array 150 disposed thereon, particularly the high refractive index nanostructure 151H. Additionally, the spacer layer 125 may serve as a planarization layer to make the thickness of the plurality of high refractive index nanostructures 151H uniform. Additionally, the spacer layer 125 may serve to provide a gap to focus the planar nano-optical microlens 151 on the photo-sensing cells 111, 112, and 113. However, if the focal length of the planar nano-optical microlens 151 is not long, the spacer layer 125 may be omitted.

Meanwhile, in the cross-sectional view of the pixel array 1100 shown in FIG. 4A, for convenience, the first color filter 141, the second color filter 142, and the third color filter 143 are shown sequentially arranged along the horizontal direction. However, it is not necessarily limited to this. In the pixel array 1100, an arrangement of a plurality of pixels that sense light of different wavelengths can be implemented in various ways. FIGS. 26A to 26C exemplarily show various pixel arrangements of the pixel array 1100.

First, Figure 26a shows a Bayer pattern that is generally adopted in the image sensor 1000. Referring to Figure 26a, one unit pattern includes four quadrant regions, and the first to fourth quadrants are blue pixel (B), green pixel (G), red pixel (R), and green pixel, respectively. It can be a pixel (G). These unit patterns are arranged two-dimensionally and repeatedly along the first direction (X direction) and the second direction (Y direction). In other words, within a unit pattern in the form of a 2×2 array, two green pixels (G) are arranged diagonally on one side, and one blue pixel (B) and one red pixel (R) are placed diagonally on the other side. is placed. Looking at the overall pixel arrangement, a first row in which a plurality of green pixels (G) and a plurality of blue pixels (B) are alternately arranged along the first direction, and a plurality of red pixels (R) and a plurality of green pixels (G) are arranged alternately in the first direction. Second rows alternately arranged along the first direction are repeatedly arranged along the second direction.

The pixel array 1100 can be arranged in various ways other than the Bayer pattern. For example, referring to FIG. 26b, a magenta pixel (M), a cyan pixel (C), a yellow pixel (Y), and a green pixel (G) form one unit pattern. A CYGM arrangement is also possible. Additionally, referring to FIG. 26C, an RGBW arrangement in which green pixels (G), red pixels (R), blue pixels (B), and white pixels (W) form one unit pattern is also possible. Additionally, although not shown, the unit pattern may have a 3×2 array form. In addition, the pixels of the pixel array 1100 may be arranged in various ways depending on the color characteristics of the image sensor 1000. Below, it will be explained that the pixel array 1100 of the image sensor 1000 has a Bayer pattern as an example, but the operating principle can be applied to other types of pixel arrays other than the Bayer pattern.

In the above-described embodiments, it has been described that the color filter layer 140 is used for color separation of incident light, but the color separation lens array that collects light of the color corresponding to each pixel using a nano-pattern is used as the color filter layer 140. ) or can be used alone without the color filter layer 140. Figures 27a and 27b are conceptual diagrams showing the schematic structure and operation of a color separation lens array according to an embodiment.

Referring to FIG. 27A, the color separation lens array 130 may include nanoposts (NPs) that change the phase of the incident light (Li) differently depending on the incident position, and the first wavelength light included in the incident light (Li). A first area 131 corresponding to the first target area (R1) where (Lλ1) is focused, and a second target area (R2) where the second wavelength light (Lλ2) included in the incident light (Li) is focused. It may be divided into a second area 132. The first and second regions 131 and 132 may each include one or more nanoposts (NP) and may be arranged to face the first and second target regions R1 and R2, respectively.

The color separation lens array 130 forms different phase distributions for the first and second wavelength lights (Lλ1 and Lλ2) included in the incident light (Li), and directs the first wavelength light (Lλ1) to the first target position (R1). ), the second wavelength light (Lλ2) can be condensed to the second target position (R2).

For example, referring to Figure 27b, the color separation lens array 130 is positioned immediately after passing through the color separation lens array 130, that is, at the lower surface position of the color separation lens array 130, the first wavelength The light Lλ1 has a first phase distribution PP1 and the second wavelength light Lλ2 has a second phase distribution PP2, so that the first and second wavelength lights Lλ1 and Lλ2 each have a corresponding target. Light can be concentrated at positions (R1, R2). Specifically, the first wavelength light (Lλ1) passing through the color separation lens array 130 is largest at the center of the first area 131 and moves in a direction away from the center of the first area 131, that is, the second area ( It may have a phase distribution (PP1) that decreases in the 132) direction. This phase distribution is similar to the phase distribution of light that passes through a convex lens, for example, a micro lens with a convex center, and converges to one point, and the first wavelength light (Lλ1) can be focused on the first target region (R1). there is. In addition, the second wavelength light Lλ2 passing through the color separation lens array 130 is largest at the center of the second area 132 and moves away from the center of the second area 132, that is, the first area 131 ) direction, the phase distribution PP2 decreases, and the light can be concentrated into the second target area R2.

Since the refractive index of a material varies depending on the wavelength of light to which it reacts, as shown in FIG. 27b, the color separation lens array 130 can provide different phase distributions for the first and second wavelength lights (Lλ1 and Lλ2). there is. In other words, even for the same material, the refractive index is different depending on the wavelength of light reacting with the material, and the phase delay experienced by light when passing through the material is also different for each wavelength, so a different phase distribution can be formed for each wavelength. For example, the refractive index of the first region 131 for the first wavelength light (Lλ1) may be different from the refractive index of the first region 131 for the second wavelength light (Lλ2), and the first region 131 Since the phase delay experienced by the first wavelength light (Lλ1) passing through ) and the phase delay experienced by the second wavelength light (Lλ2) passing through the first region 131 may be different, the color designed in consideration of the characteristics of such light The separation lens array 130 may provide different phase distributions for the first and second wavelength lights (Lλ1 and Lλ2).

The color separation lens array 130 may include nanoposts (NPs) arranged in a specific rule so that the first and second wavelength lights (Lλ1 and Lλ2) have first and second phase distributions (PP1 and PP2), respectively. You can. Here, the rule is applied to parameters such as the shape, size (width, height), spacing, and array form of the nanopost (NP), and these parameters are applied to the phase to be implemented through the color separation lens array 130. It can be determined according to the profile (phase profile).

The rules for arranging nanoposts (NPs) in the first area 131 and the rules for arranging them in the second area 132 may be different. In other words, the shape, size, spacing, and/or arrangement of the nanoposts (NPs) provided in the first region 131 are the shape, size, spacing, and/or arrangement of the nanoposts (NPs) provided in the second region 132. and/or may be different from the arrangement.

Nanoposts (NPs) may have a cross-sectional diameter of a sub-wavelength. Here, sub-wavelength refers to a wavelength smaller than the wavelength band of light that is the branching target. For example, the nanopost (NP) may have a smaller dimension than the shorter wavelength of the first wavelength or the second wavelength. When the incident light (Li) is visible light, the diameter of the nanopost (NP) cross-section may have dimensions smaller than 400 nm, 300 nm, or 200 nm, for example. The height of the nanopost (NP) may be 500 nm to 1500 nm, and the height may be greater than the diameter of the cross section. Although not shown, a nanopost (NP) may be a combination of two or more posts stacked in the height direction (Z direction).

Nanoposts (NPs) may be made of a material with a higher refractive index than surrounding materials. For example, nanoposts (NPs) may include c-Si, p-Si, a-Si, and III-V compound semiconductors (GaP, GaN, GaAs, etc.), SiC, TiO2, SiN, and/or combinations thereof. You can. Nanoposts (NPs) that have a difference in refractive index from the surrounding material can change the phase of light passing through the nanoposts (NPs). This is due to phase delay caused by the sub-wavelength shape size of the nanopost (NP), and the degree of phase delay is determined by the detailed shape size and arrangement type of the nanopost (NP). The material surrounding the nanopost (NP) may be made of a dielectric material having a lower refractive index than the nanopost (NP), for example, SiO ₂ or air.

The first and second wavelengths may be visible light wavelength bands, but are not limited thereto and may operate at various wavelengths depending on the arrangement rules of nanoposts (NPs). In addition, although two wavelengths are diverged and condensed as an example, the incident light may be diverged and condensed in three or more directions depending on the wavelength.

Below, an example in which the previously described color separation lens array 130 is applied to the pixel array 1100 of the image sensor 1000 will be described in more detail.

FIGS. 28A and 28B are schematic cross-sectional views of a pixel array of an image sensor according to an embodiment, respectively. Figure 29a is a plan view schematically showing the arrangement of the photo-sensing cells, Figure 29b is a plan view exemplarily showing the arrangement of the nanoposts of the color separation lens array, and Figure 29c is a detailed enlarged view of a portion of Figure 29b. It is a floor plan.

Referring to FIGS. 28A and 28B, the pixel array 1100 is disposed on a sensor substrate 110 including a plurality of photosensing cells 111, 112, 113, and 114 that sense light. a color filter layer 140, a planar nano-optical microlens array 150 disposed on the color filter layer 140, a transparent spacer layer 120 disposed on the planar nano-optical microlens array 150, and a spacer layer ( It may include a color separation lens array 130 disposed on 120).

As shown in FIG. 28A, the first and second photosensing cells 111 and 112 are alternately arranged along the first direction (X direction), and in a cross section with different positions in the Y direction, the third and second photosensing cells 111 and 112 are arranged alternately as shown in FIG. 28B. Four light sensing cells 113 and 114 may be arranged alternately. In addition, as shown in FIG. 28A, the first and second color filters 141 and 142 are arranged alternately along the 143, 141) can be arranged alternately. Figure 29a shows the arrangement of photo-sensing cells when the pixel array 1100 has a Bayer pattern as shown in Figure 26a. This arrangement is for sensing incident light by dividing it into unit patterns such as Bayer patterns. For example, the first and fourth photo-sensing cells 111 and 114 arranged opposite the first color filter 141 are The second photo-sensing cell 112, which senses light of one wavelength and is disposed opposite to the second color filter 142, senses light of the second wavelength, and the third cell 112 is disposed opposite to the third color filter 143. The light sensing cell 113 can sense third wavelength light. Below, the first wavelength light is illustrated as green light, the second wavelength light as blue light, and the third wavelength light as red light, and the first and fourth photosensing cells 111 and 114 correspond to the green pixel (G) and the third wavelength light is illustrated as red light. The second photo-sensing cell 112 may correspond to the blue pixel (B) and the third photo-sensing cell 113 may correspond to the red pixel (R). Although not shown, a separator for cell separation may be further formed at the boundary between cells.

The spacer layer 120 is disposed between the sensor substrate 110 and the color separation lens array 130 and serves to maintain a constant distance between the sensor substrate 110 and the color separation lens array 130. The spacer layer 120 is made of a material transparent to visible light, for example, SiO ₂ , siloxane-based spin on glass (SOG), etc., which has a lower refractive index than nanopost (NP) and has a low absorption rate in the visible light band. It may be made of dielectric material. The planar nano-optical microlens array 150 can be viewed as a structure embedded within the spacer layer 120. The thickness (h) of the spacer layer 120 may be selected within the range of ht - p ≤ h ≤ ht + p. Here, the theoretical thickness ht of the spacer layer 120 can be expressed by the following equation 1, assuming that the refractive index of the spacer layer 120 for the wavelength of λ0 is n and the pitch of the photo-sensing cell is p.

The theoretical thickness ht of the spacer layer 120 refers to the focal distance at which light with a wavelength of λ0 is focused on the upper surface of the photosensing cells 111, 112, 113, and 114 by the color separation lens array 130. You can. λ0 may be a standard wavelength for determining the thickness (h) of the spacer layer 120, and the thickness of the spacer layer 120 may be designed based on 540 nm, the central wavelength of green light.

The color separation lens array 130 is supported by the spacer layer 120 and is disposed between nanoposts (NPs) that change the phase of incident light and has a lower refractive index than the nanoposts (NPs). It may include a dielectric such as air or SiO ₂ .

Referring to FIG. 29B, the color separation lens array 130 includes first to fourth regions 131, 132, 133 corresponding to the first to fourth photo-sensing cells 111, 112, 113, and 114 of FIG. 29A. 134). The first to fourth regions 131, 132, 133, and 134 may be disposed to face the first to fourth photosensing cells 111, 112, 113, and 114, respectively. For example, the first area 131 of the color separation lens array 130 is arranged to correspond to the first photo-sensing cell 111, and the second area 132 is arranged to correspond to the second photo-sensing cell 112. The third area 133 may be arranged to correspond to the third photo-sensing cell 113, and the fourth area 134 may be arranged to correspond to the fourth photo-sensing cell 114. The first to fourth regions 131, 132, 133, and 134 have a first row in which the first and second regions 131 and 132 are arranged alternately, and a row in which the third and fourth regions 133 and 134 are alternately arranged. The rows may be two-dimensionally arranged along the first direction (X direction) and the second direction (Y direction) so that the second rows alternately repeat each other. The color separation lens array 130 also includes a plurality of unit patterns arranged two-dimensionally like the photo-sensing cell array of the sensor substrate 110, and each unit pattern is the first to fourth unit patterns arranged in a 2×2 shape. It includes regions 131, 132, 133, and 134.

28A and 28B show that the first to fourth regions 131, 132, 133, and 134 and the first to fourth photosensing cells 111, 112, 113, and 114 have the same size and face each other in the vertical direction. Although the structure is shown as an example, the color separation lens array 130 may be divided into a plurality of areas defined in different forms, such as an area for concentrating the first wavelength light and an area for concentrating the second wavelength light.

The color separation lens array 130 diverges and focuses the first wavelength light into the first photo-sensing cell 111 and the fourth photo-sensing cell 114, and diverges the second wavelength light into the second photo-sensing cell 112. It may include nanoposts (NPs) whose size, shape, spacing, and/or arrangement are determined so that the third wavelength light is branched and concentrated into the third photo-sensing cell 113. Meanwhile, the thickness (Z direction) of the color separation lens array 130 may be similar to the height of the nanopost (NP) and may be 500 nm to 1500 nm.

Referring to FIG. 29B, the first to fourth regions 131, 132, 133, and 134 may include cylindrical nanoposts (NPs) with a circular cross-section, and nano-posts (NPs) with different cross-sectional areas are located at the center of each region. Posts (NPs) may be placed, and nanoposts (NPs) may also be placed at the center of the border between pixels and at the intersection of the pixel border. The cross-sectional area of the nanopost (NP) placed at the boundary between pixels may be smaller than that of the nanopost (NP) placed at the center of the pixel.

FIG. 29C shows in detail the arrangement of nanoposts (NPs) included in some regions of FIG. 29B, that is, the first to fourth regions 131, 132, 133, and 134 constituting the unit pattern. In Figure 29c, nanoposts (NPs) are labeled p1 to p9 according to the detailed positions of the unit pattern. Referring to FIG. 29C, among the nanoposts (NP), the cross-sectional areas of the nanopost (p1) disposed at the center of the first region 131 and the nanopost (p4) disposed at the center of the fourth region 134 are The cross-sectional area of the nanopost (p2) placed at the center of the second area 132 or the nanopost (p3) placed at the center of the third area 133 is larger than that of the nanopost placed at the center of the second area 132. The cross-sectional area of the post p2 is larger than the cross-sectional area of the nanopost p3 disposed at the center of the third region 133. However, this is only one example, and nanoposts (NPs) of various shapes, sizes, and arrangements can be applied as needed.

Nanoposts (NPs) provided in the first and fourth regions 131 and 134 corresponding to the green pixel (G) follow different distribution rules along the first direction (X direction) and the second direction (Y direction). You can have it. For example, nanoposts NPs disposed in the first and fourth regions 131 and 134 may have different size arrangements along the first direction (X direction) and the second direction (Y direction). As shown in FIG. 29C, among the nanoposts (NP), the nanopost (p5) located at the border between the first region 131 and the second region 132 adjacent in the first direction (X direction) The cross-sectional areas of the nanoposts p6 located at the boundary with the third region 133 adjacent in the second direction (Y direction) are different from each other. Likewise, the cross-sectional area of the nanopost (p7) located at the boundary between the fourth area 134 and the third area 133 adjacent in the first direction (X direction) and the second area adjacent to the second direction (Y direction) The cross-sectional areas of the nanoposts (p8) located at the boundary with the region 132 are different from each other.

On the other hand, nanoposts (NPs) disposed in the second area 132 corresponding to the blue pixel (B) and the third area 133 corresponding to the red pixel (R) are located in the first direction (X direction) and the second direction. It can have a symmetrical distribution rule along the direction (Y direction). As shown in FIG. 29C, among the nanoposts (NPs), a nanopost (p5) located at the boundary between the second region 132 and adjacent pixels in the first direction (X direction) and the second direction (Y direction) The cross-sectional areas of the nanoposts (p8) placed on the boundary between adjacent pixels are the same, and similarly in the third region 133, the nanoposts (p7) placed on the boundary between adjacent pixels in the first direction (X direction) and the second direction The cross-sectional areas of the nanoposts (p6) placed at the boundary between adjacent pixels in the (Y direction) are the same.

Meanwhile, the nanoposts p9 disposed at the four corners of each of the first to fourth regions 131, 132, 133, and 134, that is, at the positions where the four regions intersect, have the same cross-sectional area.

This distribution results from the arrangement of pixels in a Bayer pattern. In both the blue pixel (B) and the red pixel (R), the pixels adjacent to each other in the first direction (X direction) and the second direction (Y direction) are the same as the green pixel (G), while the pixels corresponding to the first area 131 are the same as the green pixel (G). The green pixel (G) is different from each other in that the pixel adjacent to it in the first direction (X direction) is the blue pixel (B) and the pixel adjacent to the second direction (Y direction) is the red pixel (R), and is located in the fourth region 134. The corresponding green pixels (G) are different, with the pixel adjacent to them in the first direction (X direction) being the red pixel (R) and the pixel adjacent to the second direction (Y direction) being the blue pixel (B). In addition, the green pixels (G) corresponding to the first area 131 and the fourth area 134 have the same green pixels (G) as the pixels adjacent to each other in four diagonal directions, and the green pixels (G) corresponding to the second area 132 The blue pixel (B) has pixels adjacent to it in four diagonal directions as the red pixel (R), and the red pixel (R) corresponding to the third area 133 has pixels adjacent to it in four diagonal directions as the blue pixel (B). ) are the same as each other. Therefore, in the second and third regions 132 and 133 corresponding to the blue pixel (B) and the red pixel (R), nanoposts (NPs) are arranged in the form of 4-fold symmetry, and the green Nanoposts (NPs) may be arranged in the form of 2-fold symmetry in the first and fourth regions 131 and 134 corresponding to the pixel (G). In particular, the first and fourth regions 131 and 134 are rotated by 90 degrees with respect to each other.

The nanoposts (NPs) in FIGS. 29B and 29C are all shown as having a symmetrical circular cross-sectional shape, but some nanoposts with an asymmetrical cross-sectional shape may be included. For example, in the first and fourth regions 131 and 134 corresponding to the green pixel (G), nano nanometers have asymmetric cross-sectional shapes with different widths in the first direction (X direction) and the second direction (Y direction). A post is adopted, and the second and third areas 132 and 133 corresponding to the blue pixel (B) and the red pixel (R) have the same width in the first direction (X direction) and the second direction (Y direction). Nanoposts with a symmetrical cross-sectional shape can be employed.

The arrangement rule of the illustrated color separation lens array 130 diverges and condenses the first wavelength light into the first photo-sensing cell 111 and the fourth photo-sensing cell 114, and then condenses the light of the first wavelength into the first photo-sensing cell 111 and the fourth photo-sensing cell 114. This is an example for implementing a phase distribution that branches and condenses the second wavelength light and branches and condenses the third wavelength light in the third photo-sensing cell 113, and is not limited to the pattern shown.

FIG. 30A shows the phase distribution of the first and second wavelength light passing through the color separation lens array 130 along the line I-I' of FIG. 29B, and FIG. 30B shows the phase distribution of the first and second wavelength light passing through the color separation lens array 130. The phase of the light at the wavelength is shown at the center of the first to fourth regions 131, 132, 133, and 134, and Figure 30c shows that the second wavelength light passing through the color separation lens array 130 is in the first to fourth regions (131, 132, 133, and 134). 131, 132, 133, 134) This is a diagram showing the phase at the center. The phase distribution of the first and second wavelength light shown in FIG. 30A is the same as the phase distribution of the first and second wavelength light exemplarily illustrated in FIG. 27B.

Referring to FIGS. 30A and 30B, the first wavelength light passing through the color separation lens array 130 is largest at the center of the first region 131 and decreases in a direction away from the center of the first region 131. It can have a phase distribution. Specifically, the phase of the first wavelength light is located immediately after passing through the color separation lens array 130, that is, at the lower surface of the color separation lens array 130 or the upper surface of the spacer layer 120, in the first region 131. ) is largest at the center of the first area 131, and gradually becomes smaller in a concentric circle as it moves away from the center of the first area 131, and becomes smallest at the centers of the second and third areas 132 and 133 in the X and Y directions. , becomes minimum at the contact point between the first area 131 and the fourth area 134 in the diagonal direction. If 2π is set based on the phase of the first wavelength light emitted from the center of the first region 131, the phase is 0.9π to 1.1 π at the centers of the second and third regions 132 and 133, and the fourth region 134 Light with a phase of 2π may be emitted from the center, and light with a phase of 1.1π to 1.5π may be emitted from the contact point between the first region 131 and the fourth region 134. Meanwhile, the first phase distribution PP1 does not mean that the amount of phase delay of light passing through the center of the first area 131 is the largest. When the phase of the light passing through the first area 131 is set to 2π, the phase value of the light passing through another location (if the phase delay is larger than 2π) is removed by 2nπ, and the remaining value, that is, the wrapped value, is It may be a distribution of phases. For example, if the phase of light passing through the first area 131 is 2π and the phase of light passing through the center of the second area 132 is 3π, the phase in the second area 132 is 3π. Remove 2π (if n=1), and the remaining π may be.

Referring to FIGS. 30A and 30C, the second wavelength light passing through the color separation lens array 130 is largest at the center of the second region 132 and decreases in a direction away from the center of the second region 132. It can have a phase distribution. Specifically, at the position immediately after passing through the color separation lens array 130, the phase of the second wavelength light is greatest at the center of the second area 132, and the farther away from the center of the second area 132, the more concentric the shape. gradually becomes smaller, reaching a minimum at the centers of the first and fourth areas 131 and 134 in the X and Y directions, and at the center of the third area 133 in the diagonal direction. If the phase of the second wavelength light at the center of the second region 132 is 2π, the phase of the second wavelength light is 0.9π to 1.1π at the centers of the first and fourth regions 131 and 134, and the phase of the second wavelength light is 0.9π to 1.1π at the center of the first and fourth regions 131 and 134, and the phase of the second wavelength light is 0.9π to 1.1π at the center of the first and fourth regions 131 and 134, and 133) At the center, it may be a value smaller than π, for example, 0.2π to 0.9π.

FIG. 30D exemplarily shows the direction of travel of the first wavelength light incident on and around the first region 131 of the color separation lens array 130 of FIGS. 30A and 30B, and FIG. 30E shows the direction of travel of the first wavelength light. This is a diagram illustrating a micro lens array that functions equivalently to the color separation lens array 130.

The first wavelength light incident around the first area 131 is focused by the color separation lens array 130 into the first photo-sensing cell 111, as shown in FIG. 30D, and the first photo-sensing cell ( 111), the first wavelength light coming from the first to third areas 131, 132, and 133 is incident. The phase distribution of the first wavelength light described in FIGS. 30A and 30B is a virtual distribution created by connecting the centers of the first region 131 and the two adjacent second regions 132 and two third regions 133 on one side. It is similar to the phase distribution of light passing through the first micro lens ML1. Therefore, as shown in FIG. 30E, the color separation lens array 130 has a plurality of first micros arranged around the first area 131 for the first wavelength light incident on the periphery of the first area 131. It can play an equivalent role to the array of the lens ML1. Since each of the equivalent first micro lenses ML1 has a larger area than the corresponding first photo-sensing cell 111, not only the first wavelength light incident on the first region 131 but also the second and third regions 132 , 133), the light of the first wavelength incident can also be focused on the first photo-sensing cell 111. The area of the first micro lens ML1 may be 1.2 to 2 times larger than the area of the corresponding first photo-sensing cell 111.

FIG. 30F exemplarily shows the direction of travel of the second wavelength light incident on and around the second region 132 of the color separation lens array 130 of FIGS. 30A and 30B, and FIG. 30G shows the direction of the second wavelength light for the second wavelength light. This is a diagram illustrating a micro lens array that functions equivalently to the color separation lens array 130.

The second wavelength light is focused by the color separation lens array 130 into the second photo-sensing cell 112 as shown in FIG. 30F, and the second photo-sensing cell 112 includes first to fourth regions 131, 132, The second wavelength light coming from 133, 134) is incident. The phase distribution of the second wavelength light previously described in FIGS. 30A and 30C is a virtual second micro lens ML2 made by connecting the centers of four adjacent third regions 133 with the vertices of the second region 132 facing each other. It is similar to the phase distribution of light passing through. Therefore, as shown in FIG. 30g, the color separation lens array 130 plays an equivalent role to the array of the plurality of second micro lenses ML2 arranged around the second region 132 for the second wavelength light. can do. Since each second micro lens ML2 is larger than the corresponding second photo-sensing cell 112, not only the second wavelength light incident in the direction of the second photo-sensing cell 112 but also the first, third and fourth Light of the second wavelength incident in the direction of the photo-sensing cells 111, 113, and 114 can also be focused on the second photo-sensing cell 112. The area of the second micro lens ML2 may be 1.5 to 4 times larger than the area of the corresponding second photo-sensing cell 112.

FIG. 31A shows the phase distribution of the first and third wavelengths of light that passed through the color separation lens array 130 along the line II-II' of FIG. 29B, and FIG. 31B shows the phase distribution of the first and third wavelengths of light that passed through the color separation lens array 130. The phase of the wavelength light is shown at the center of the first to fourth regions 131, 132, 133, and 134, and Figure 31c shows that the first wavelength light passing through the color separation lens array 130 is divided into the first to fourth regions (131, 132, 133, and 134). 131, 132, 133, 134) This is a diagram showing the phase at the center.

Referring to FIGS. 31A and 31B, the third wavelength light passing through the color separation lens array 130 has a fourth phase distribution PP4 similar to the second wavelength light previously described centered on the second region 132. , may have a phase distribution that is largest at the center of the third area 133 and decreases in a direction away from the center of the third area 133. Specifically, the third wavelength light is largest at the center of the third area 133 at the position immediately after passing through the color separation lens array 130, and becomes more concentric as it moves away from the center of the third area 133. It gradually becomes smaller, reaching a minimum at the center of the first and fourth areas 131 and 134 in the X and Y directions, and at the center of the second area 132 in the diagonal direction. If the phase of the third wavelength light at the center of the third region 133 is 2π, the phase of the third wavelength light is 0.9π to 1.1π at the centers of the first and fourth regions 131 and 134, and the phase of the third wavelength light is 0.9π to 1.1π at the center of the first and fourth regions 131 and 134, and the phase of the third wavelength light is 0.9π to 1.1π at the center of the first and fourth regions 131 and 134, and 132), it may be a value smaller than π, approximately 0.2π to 0.9π.

FIG. 31D exemplarily shows the direction of travel of the third wavelength light incident on and around the third region 133 of the color separation lens array 130 of FIGS. 31A and 31B, and FIG. 31E shows the direction of travel of the third wavelength light. This is a diagram illustrating a micro lens array that functions equivalently to the color separation lens array 130.

The third wavelength light is focused by the color separation lens array 130 into the third photo-sensing cell 113, as shown in FIG. 31D, and the third photo-sensing cell 113 has first to fourth regions ( The third wavelength light coming from 131, 132, 133, 134) is incident. The phase distribution of the third wavelength light previously described in FIGS. 31A and 31B is a virtual third micro lens ML3 made by connecting the centers of four adjacent second regions 132 with the vertices facing the third region 133. It is similar to the phase distribution of light passing through. Therefore, as shown in Figure 31e, the color separation lens array 130 is equivalent to the plurality of third micro-lens (ML3) arrays arranged around the third photo-sensing cell 113 for the third wavelength light. can play a role. Since the area of each of the third micro lenses ML3 is larger than that of the corresponding third photo-sensing cell 113, not only the third wavelength light incident in the direction of the third photo-sensing cell 113 but also the first, second and 4 The third wavelength light incident in the direction of the photo-sensing cells 111, 112, and 114 can also be focused on the third photo-sensing cell 113. The area of the third micro lens ML3 may be 1.5 to 4 times larger than the area of the corresponding third photo-sensing cell 113.

Referring to FIGS. 31A and 31C, the first wavelength light incident around the fourth region 134 has a phase distribution similar to the first wavelength light described above centered on the first region 131, and is transmitted to the fourth region ( It may have a phase distribution that is largest at the center of the region 134 and decreases in a direction away from the center of the fourth region 134. The phase centered on the fourth area 134 of the first wavelength light is greatest at the center of the fourth area 134 at the position immediately after passing through the color separation lens array 130, and the phase of the first wavelength light is largest at the center of the fourth area 134. As the distance from It becomes minimum at the contact point of (134). If the phase of the first wavelength light is 2π at the center of the fourth region 134, the phase is 0.9π to 1.1π at the center of the second and third regions 132 and 133, and 2π at the center of the first region 131. At the contact point between the first area 131 and the fourth area 134, it may be 1.1 π to 1.5 π.

FIG. 31F exemplarily shows the direction of travel of the first wavelength light incident on and around the fourth region 134 of the color separation lens array 130 of FIGS. 31A and 31B, and FIG. 31G shows the direction of travel for the first wavelength light. This is a diagram illustrating a micro lens array that functions equivalently to the color separation lens array 130. The first wavelength light is focused into two photo-sensing cells 111 and 114, and the phase distribution and direction of light of the first wavelength light incident on the fourth area are determined by the phase of the first wavelength light incident on the first area 131. Since the distribution and direction of progress are similar, redundant explanations will be omitted.

Referring to FIG. 31f, the first wavelength light incident on the periphery of the fourth area 134 is focused on the fourth photo-sensing cell 114 by the color separation lens array 130, and the fourth photo-sensing cell 114 ), the first wavelength light coming from the second to fourth areas 132, 133, and 134 is incident. As shown in Figure 31g, the color separation lens array 130 has a plurality of fourth micros arranged around the fourth photo-sensing cell 114 for the first wavelength light incident on the periphery of the fourth area 134. It can play an equivalent role to the lens (ML4) array.

Meanwhile, the color separation lens array 130 also operates efficiently for light incident in a specific angle range, but if the incident angle moves away from the specific angle range, color separation performance may deteriorate. Accordingly, taking into account the main ray angle of the incident light that varies depending on the position on the pixel array 1100, the arrangement of the nanoposts of the color separation lens array 130 can be designed differently. Figures 32A to 32C are plan views showing changes in the arrangement shape of the nanoposts of the color separation lens array 130 depending on the position on the pixel array 1100. In particular, Figure 32a shows the position of the nanopost (NP) placed at the center of the pixel array 1100, and Figure 32b shows the position of the nanopost (NP) placed between the center and the edge of the pixel array 1100. , Figure 32c shows the position of the nanopost (NP) placed at the edge of the pixel array 1100. FIGS. 32A to 32C are not intended to limit the specific arrangement of the nanoposts (NPs), but are merely intended to conceptually explain changes in the relative positions of the nanoposts (NPs) depending on their positions on the pixel array 1100.

As shown in FIGS. 32A to 32C, the first, second, third, and fourth regions of the color separation lens array 130 have corresponding It can be positioned shifted further away from the pixel or photo-sensing cells. For example, in the center of the pixel array 1100, the center of the color separation lens array 130, or the center of the sensor substrate 110, the first, second, and third regions of the color separation lens array 130 The positions of the region and the fourth region may coincide with the positions of the green pixel, blue pixel, red pixel, and green pixel (or the positions of the photo-sensing cells corresponding thereto). As the distance from the center of the pixel array 1100, the center of the color separation lens array 130, or the center of the sensor substrate 110 increases, the first, second, and third regions of the color separation lens array 130 become larger. , and the fourth region may be shifted further away from the positions of the green pixel, blue pixel, red pixel, and green pixel, respectively (or the positions of the photo-sensing cells corresponding thereto). The extent to which the first, second, third, and fourth regions of the color separation lens array 130 are shifted may be determined by the principal ray angle of light incident on the color separation lens array 130. In particular, the first region, second region, and third region of the color separation lens array 130 at the periphery of the pixel array 1100, the peripheral portion of the color separation lens array 130, or the peripheral portion of the sensor substrate 110, and the fourth region may be shifted toward the center of the pixel array 1100 with respect to the first, second, third, and fourth photosensing cells corresponding thereto, respectively.

Although it has been described as the center of the pixel array 1100 for convenience so far, the pixel array 1100 includes a planar nano-optical microlens array 150, a color separation lens array 130, and a sensor substrate 110 arranged to face each other. Therefore, the center of the pixel array 1100 may also mean the center of the planar nano-optical microlens array 150, the center of the color separation lens array 130, or the center of the sensor substrate 110. Similarly, hereinafter, the periphery/edge of the pixel array 1100 is the periphery/edge of the planar nano-optical microlens array 150, the periphery/edge of the color separation lens array 130, or the periphery/edge of the sensor substrate 110. It can mean.

Figure 33 is a cross-sectional view showing a schematic structure of a pixel array of an image sensor according to another embodiment. Referring to FIG. 33, the pixel array 1100 differs from the above-described embodiments in that it includes a color separation lens array 130 including nanoposts (NPs) stacked in two stages. The nanopost (NP) may include a first nanopost (NP1) disposed on the spacer layer 120, and a second nanopost (NP2) disposed on the first nanopost (NP1). The second nanopost NP2 may be shifted along the tilt direction of light with respect to the first nanopost NP1. For example, when light incident on the color separation lens array 130 is inclined from right to left, the second nanopost NP2 may be shifted to the right with respect to the first nanopost NP1. Conversely, when the light incident on the color separation lens array 130 is inclined from left to right, the second nanopost NP2 may be shifted to the left with respect to the first nanopost NP1.

Additionally, considering the principal ray angle of light incident on the pixel array 1100, the second nanopost NP2 may be shifted toward the center of the pixel array 1100 with respect to the first nanopost NP1. For example, the second nanopost NP2 is shifted further to the right with respect to the first nanopost NP1 as it moves from the center to the left edge of the pixel array 1100, and moves from the center of the pixel array 1100 to the right edge. Increasingly, the second nanopost (NP2) may be shifted further to the left with respect to the first nanopost (NP1).

Likewise, the third area 133 and the fourth area 134 of the color separation lens array 130 have corresponding red pixels (or third photo-sensing cells 113) and green pixels (or fourth photo-sensing cells 113), respectively. is shifted toward the center of the pixel array 1100 with respect to the cell 114). For example, as you move from the center of the pixel array 1100 to the left edge, the third and fourth areas 133 and 134 of the color separation lens array 130 move to the right with respect to the corresponding green and red pixels, respectively. It can be further shifted to . Although not shown, the first and second regions disposed on different cross-sections of the color separation lens array 130 also have corresponding green pixels (or first photo-sensing cells) and blue pixels (or second photo-sensing cells). ) may be shifted toward the center of the pixel array 1100.

In particular, the third area 133 and the fourth area 134 of the color separation lens array 130 are located at the center of the corresponding third photo-sensing cell 113 and the center of the fourth photo-sensing cell 114, respectively. They can be shifted to focus red light and green light, respectively. The distance s at which the third area 133 and the fourth area 134 of the color separation lens array 130 are shifted may be determined, for example, by Equation 2 below.

In Equation 2, d is the shortest straight line distance or gap between the lower surface of the color separation lens array 130 and the upper surface of the sensor substrate 110, and CRA' is the angle of incidence of light incident on the sensor substrate 110. Additionally, CRA' can be determined by Equation 3 below.

In Equation 3, CRA is the angle of incidence of light incident on the color separation lens array 130, and n is the average refractive index of materials disposed between the color separation lens array 130 and the sensor substrate 110. Therefore, the distance s by which the third region 133 and the fourth region 134 of the color separation lens array 130 are shifted from the corresponding pixels is the angle of incidence of light incident on the color separation lens array 130, and the color It may be determined by the average refractive index of the materials disposed between the separation lens array 130 and the sensor substrate 110.

Figure 34 is a cross-sectional view showing a schematic structure of a pixel array of an image sensor according to another embodiment. By using the color separation lens array 130, the light use efficiency of the image sensor 1000 can be improved by reducing loss caused by the color filter layer 140. Additionally, high color purity can be achieved by using the color separation lens array 130 and the color filter layer 140 together. If sufficient color separation occurs by the color separation lens array 130 and high color purity can be achieved, the color filter layer 140 may be omitted, as shown in FIG. 34. The configuration shown in FIG. 34 is the same as that shown in FIG. 33 except that the color filter layer 140 is omitted.

Figure 35 is a plan view exemplarily showing the shift form of nanoposts arranged two-dimensionally in a color separation lens array. Referring to FIG. 35, the second nanopost NP2 of the color separation lens array 130 at the center of the pixel array 1100 is not shifted relative to the first nanopost NP1. On the other hand, at the periphery of the pixel array 1100, the second nanopost NP2 of the color separation lens array 130 is shifted toward the center of the pixel array 1100 with respect to the first nanopost NP1. Accordingly, the total area of the color separation lens array 130 may be smaller than the total area of the pixel array 1100 or the total area of the sensor substrate 110. Additionally, the total area of the color separation lens array 130 may be approximately equal to the total area of the planar nano-optical microlens array 150.

The color separation lens array 130 shown in FIG. 29B is just one example, and various types of color separation lens array 130 may be designed depending on the color characteristics of the image sensor, pixel pitch, angle of incidence of incident light, etc. In addition, so far, the color separation lens array 130 has been described as including a plurality of cylindrical nanoposts (NPs) spaced apart from each other, but it is not necessarily limited thereto.

For example, FIGS. 36A and 36B are plan views illustrating the unit pattern form of a color separation lens array according to another embodiment that can be applied to a Bayer pattern image sensor. Referring to FIG. 36A, the color separation lens array 130' may include first to fourth areas 131', 132', 133', and 134' in a binary form digitized into a 16×16 rectangle. The unit pattern of the color separation lens array 130' has a 32×32 rectangular shape. Referring to Figure 36b, each of the first to fourth regions 131", 132", 133", and 134" of the color separation lens array 130" may have a non-digitized continuous curved shape. Figure 36a and in the first to fourth regions (131', 132', 133', 134', 131", 132", 133", 134") of the color separation lens arrays (130', 130") shown in FIG. 36B. The rules applied are the same as those applied to the first to fourth regions 131, 132, 133, and 134 of the color separation lens array 130.

Color separation lens arrays 130' and 130" that satisfy the phase distribution and performance of the color separation lens array 130 described above can be designed automatically through various computer simulations. For example, genetic algorithm ( Reverse engineering method using nature-inspired algorithms such as genetic algorithm, particle swarm optimization algorithm, ant colony optimization, etc., or based on adjoint optimization algorithm Through this, the structure of the first to fourth regions 131', 132', 133', 134', 131", 132", 133", and 134" can be optimized.

The design of the color separation lens arrays (130', 130") evaluates the performance of the candidate color separation lens arrays using evaluation factors such as color separation spectrum, optical efficiency, and signal-to-noise ratio, while evaluating the first to fourth regions (131', 132). ', 133', 134', 131", 132", 133", 134") can be optimized. For example, if the target numerical value for each evaluation element is determined in advance, , the first to fourth areas (131', 132', 133', 134', 131", 132", 133", 134) in a manner that minimizes the sum of the difference between the target numerical value and the design value for the evaluation factors. ") patterns may be optimized. Alternatively, when performance is indexed for each evaluation element, the first to fourth regions 131', 132', 133', 134', 131", so that the value representing the performance is maximized. Patterns of 132", 133", and 134" can be optimized.

Figure 37 is a cross-sectional view showing a schematic structure of a pixel array of an image sensor according to another embodiment. So far, the planar nano-optical microlens array 150 has been described as being disposed between the color separation lens array 130 and the sensor substrate 110 or between the color separation lens array 130 and the color filter layer 140. For example, the planar nano-optical microlens array 150 was described as being disposed within the spacer layer 120. However, the location of the planar nano-optical microlens array 150 is not necessarily limited to this. For example, as shown in FIG. 37, the planar nano-optical microlens array 150 may be disposed on the color separation lens array 130.

By using the planar nano-optical microlens array 150 and the color separation lens array 130 together, the color separation efficiency of the color separation lens array 130 can be further improved. In particular, the color separation efficiency of the color separation lens array 130 at the periphery of the pixel array 1100 may be substantially the same as that of the color separation lens array 130 at the center of the pixel array 1100. Accordingly, relatively uniform color purity can be achieved in the entire area of the pixel array 1100.

The image sensor 1000 including the above-described color separation lens arrays 130, 130', 130" has almost no light loss due to a color filter, for example, an organic color filter, so even if the pixel size is small, the pixel A sufficient amount of light can be provided. Therefore, it is possible to produce an ultra-high-resolution, ultra-small, high-sensitivity image sensor with hundreds of millions of pixels or more. Such ultra-high-resolution, ultra-small, high-sensitivity image sensors can be employed in various high-performance optical devices or high-performance electronic devices. These electronic devices include, for example, various portable devices such as smart phones, personal digital assistants (PDAs), laptops, and PCs, home appliances, security cameras, medical cameras, automobiles, and the Internet of Things (IoT). It may be, but is not limited to, an Internet of Things (Internet of Things) device or other mobile or non-mobile computing device.

In addition to the image sensor 1000, the electronic device may further include a processor that controls the image sensor, for example, an application processor (AP), and runs an operating system or application program through the processor to run a plurality of hardware devices. Alternatively, software components can be controlled and various data processing and calculations can be performed. The processor may further include a Graphics Processing Unit (GPU) and/or an Image Signal Processor. If the processor includes an image signal processor, the image (or video) acquired by the image sensor can be stored and/or output using the processor.

FIG. 38 is a block diagram showing an example of an electronic device 1801 including an image sensor 1000. Referring to FIG. 38, in a network environment 1800, an electronic device 1801 communicates with another electronic device 1802 through a first network 1898 (short-range wireless communication network, etc.), or through a second network 1899. It is possible to communicate with another electronic device 1804 and/or the server 1808 through a long-distance wireless communication network, etc. The electronic device 1801 may communicate with the electronic device 1804 through the server 1808. The electronic device 1801 includes a processor 1820, a memory 1830, an input device 1850, an audio output device 1855, a display device 1860, an audio module 1870, a sensor module 1876, and an interface 1877. ), a haptic module (1879), a camera module (1880), a power management module (1888), a battery (1889), a communication module (1890), a subscriber identification module (1896), and/or an antenna module (1897). You can. In the electronic device 1801, some of these components (such as the display device 1860) may be omitted or other components may be added. Some of these components can be implemented as one integrated circuit. For example, the sensor module 1876 (fingerprint sensor, iris sensor, illumination sensor, etc.) may be implemented by being embedded in the display device 1860 (display, etc.).

The processor 1820 may execute software (program 1840, etc.) to control one or a plurality of other components (hardware, software components, etc.) of the electronic device 1801 connected to the processor 1820. , various data processing or calculations can be performed. As part of data processing or computation, processor 1820 loads instructions and/or data received from other components (sensor module 1876, communication module 1890, etc.) into volatile memory 1832, and volatile memory ( Commands and/or data stored in 1832) may be processed, and the resulting data may be stored in non-volatile memory 1834. The processor 1820 includes a main processor 1821 (central processing unit, application processor, etc.) and an auxiliary processor 1823 (graphics processing unit, image signal processor, sensor hub processor, communication processor, etc.) that can operate independently or together with the main processor 1821. It can be included. The auxiliary processor 1823 uses less power than the main processor 1821 and can perform specialized functions.

The auxiliary processor 1823 acts on behalf of the main processor 1821 while the main processor 1821 is in an inactive state (sleep state), or as the main processor 1821 while the main processor 1821 is in an active state (application execution state). Together with the processor 1821, it is possible to control functions and/or states related to some of the components of the electronic device 1801 (display device 1860, sensor module 1876, communication module 1890, etc.). You can. The auxiliary processor 1823 (image signal processor, communication processor, etc.) may also be implemented as part of other functionally related components (camera module 1880, communication module 1890, etc.).

The memory 1830 can store various data needed by components (processor 1820, sensor module 1876, etc.) of the electronic device 1801. Data may include, for example, input data and/or output data for software (such as program 1840) and instructions related thereto. Memory 1830 may include volatile memory 1832 and/or non-volatile memory 1834.

The program 1840 may be stored as software in the memory 1830 and may include an operating system 1842, middleware 1844, and/or applications 1846.

The input device 1850 may receive commands and/or data to be used in components (such as the processor 1820) of the electronic device 1801 from outside the electronic device 1801 (such as a user). The input device 1850 may include a microphone, mouse, keyboard, and/or digital pen (stylus pen, etc.).

The sound output device 1855 may output sound signals to the outside of the electronic device 1801. The sound output device 1855 may include a speaker and/or a receiver. The speaker can be used for general purposes such as multimedia playback or recording playback, and the receiver can be used to receive incoming calls. The receiver can be integrated as part of the speaker or implemented as a separate, independent device.

The display device 1860 can visually provide information to the outside of the electronic device 1801. The display device 1860 may include a display, a hologram device, or a projector, and a control circuit for controlling the device. The display device 1860 may include a touch circuitry configured to detect a touch, and/or a sensor circuit configured to measure the intensity of force generated by the touch (such as a pressure sensor).

The audio module 1870 can convert sound into an electrical signal or, conversely, convert an electrical signal into sound. The audio module 1870 acquires sound through the input device 1850, the sound output device 1855, and/or another electronic device (electronic device 1802, etc.) directly or wirelessly connected to the electronic device 1801. ) can output sound through speakers and/or headphones.

The sensor module 1876 detects the operating state (power, temperature, etc.) of the electronic device 1801 or the external environmental state (user state, etc.) and generates an electrical signal and/or data value corresponding to the detected state. can do. The sensor module 1876 includes a gesture sensor, a gyro sensor, a barometric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an IR (Infrared) sensor, a biometric sensor, a temperature sensor, a humidity sensor, and/or an illumination sensor. May include sensors.

The interface 1877 may support one or a plurality of designated protocols that can be used to directly or wirelessly connect the electronic device 1801 to another electronic device (such as the electronic device 1802). The interface 1877 may include a High Definition Multimedia Interface (HDMI), a Universal Serial Bus (USB) interface, an SD card interface, and/or an audio interface.

The connection terminal 1878 may include a connector through which the electronic device 1801 can be physically connected to another electronic device (such as the electronic device 1802). Connection terminal 1878 may include an HDMI connector, a USB connector, an SD card connector, and/or an audio connector (such as a headphone connector).

The haptic module 1879 can convert electrical signals into mechanical stimulation (vibration, movement, etc.) or electrical stimulation that the user can perceive through tactile or kinesthetic senses. Haptic module 1879 may include a motor, piezoelectric element, and/or electrical stimulation device.

The camera module 1880 can capture still images and moving images. The camera module 1880 may include a lens assembly including one or a plurality of lenses, the image sensor 1000 of FIG. 1, image signal processors, and/or flashes. The lens assembly included in the camera module 1880 may collect light emitted from a subject that is the target of image capture.

The power management module 1888 can manage power supplied to the electronic device 1801. The power management module 1888 may be implemented as part of a Power Management Integrated Circuit (PMIC).

Battery 1889 may supply power to components of electronic device 1801. The battery 1889 may include a non-rechargeable primary cell, a rechargeable secondary cell, and/or a fuel cell.

The communication module 1890 is configured to establish a direct (wired) communication channel and/or a wireless communication channel between the electronic device 1801 and other electronic devices (electronic device 1802, electronic device 1804, server 1808, etc.); and can support communication through established communication channels. The communication module 1890 operates independently of the processor 1820 (such as an application processor) and may include one or more communication processors that support direct communication and/or wireless communication. The communication module 1890 is a wireless communication module 1892 (cellular communication module, short-range wireless communication module, GNSS (Global Navigation Satellite System, etc.) communication module) and/or a wired communication module 1894 (LAN (Local Area Network) communication). module, power line communication module, etc.). Among these communication modules, the corresponding communication module may be a first network (1898) (a short-range communication network such as Bluetooth, WiFi Direct, or IrDA (Infrared Data Association)) or a second network (1899) (a cellular network, the Internet, or a computer network (LAN) , WAN, etc.) can communicate with other electronic devices. These various types of communication modules may be integrated into one component (such as a single chip) or may be implemented as a plurality of separate components (multiple chips). The wireless communication module 1892 uses subscriber information (international mobile subscriber identifier (IMSI), etc.) stored in the subscriber identification module 1896 to communicate within a communication network such as the first network 1898 and/or the second network 1899. The electronic device 1801 can be confirmed and authenticated.

The antenna module 1897 may transmit signals and/or power to or receive signals and/or power from the outside (such as other electronic devices). The antenna may include a radiator consisting of a conductive pattern formed on a substrate (PCB, etc.). The antenna module 1897 may include one or multiple antennas. When a plurality of antennas are included, an antenna suitable for a communication method used in a communication network such as the first network 1898 and/or the second network 1899 may be selected from among the plurality of antennas by the communication module 1890. You can. Signals and/or power may be transmitted or received between the communication module 1890 and other electronic devices through the selected antenna. In addition to the antenna, other components (RFIC, etc.) may be included as part of the antenna module 1897.

Some of the components are connected to each other through communication methods between peripheral devices (bus, General Purpose Input and Output (GPIO), Serial Peripheral Interface (SPI), Mobile Industry Processor Interface (MIPI), etc.) and send signals (commands, data, etc.) ) can be interchanged.

Commands or data may be transmitted or received between the electronic device 1801 and an external electronic device 1804 through the server 1808 connected to the second network 1899. Other electronic devices 1802 and 1804 may be the same or different types of devices from the electronic device 1801. All or part of the operations performed on the electronic device 1801 may be executed on one or more of the other electronic devices 1802, 1804, and 1808. For example, when the electronic device 1801 needs to perform a certain function or service, instead of executing the function or service itself, it performs part or all of the function or service to one or more other electronic devices. You can ask them to do it. One or more other electronic devices that have received the request may execute additional functions or services related to the request and transmit the results of the execution to the electronic device 1801. For this purpose, cloud computing, distributed computing, and/or client-server computing technologies may be used.

FIG. 39 is a block diagram illustrating the camera module 1880 of FIG. 38. Referring to FIG. 39, the camera module 1880 includes a lens assembly 1910, a flash 1920, an image sensor 1000 (see FIG. 1), an image stabilizer 1940, a memory 1950 (buffer memory, etc.), and/or an image signal processor 1960. The lens assembly 1910 may collect light emitted from a subject that is the target of image capture. The camera module 1880 may include a plurality of lens assemblies 1910, in which case the camera module 1880 may be a dual camera, a 360-degree camera, or a spherical camera. Some of the plurality of lens assemblies 1910 may have the same lens properties (angle of view, focal length, autofocus, F number, optical zoom, etc.) or may have different lens properties. The lens assembly 1910 may include a wide-angle lens or a telephoto lens.

The flash 1920 may emit light used to enhance light emitted or reflected from a subject. The flash 1920 may include one or a plurality of light emitting diodes (RGB (Red-Green-Blue) LED, White LED, Infrared LED, Ultraviolet LED, etc.), and/or a Xenon Lamp. The image sensor 1000 may be the image sensor described in FIG. 1 and can acquire an image corresponding to the subject by converting light emitted or reflected from the subject and transmitted through the lens assembly 1910 into an electrical signal. . The image sensor 1000 may include one or more sensors selected from among image sensors with different properties, such as an RGB sensor, a black and white (BW) sensor, an IR sensor, or a UV sensor. Each sensor included in the image sensor 1000 may be implemented as a charged coupled device (CCD) sensor and/or a complementary metal oxide semiconductor (CMOS) sensor.

The image stabilizer 1940 moves one or more lenses or image sensors 1000 included in the lens assembly 1910 in a specific direction in response to the movement of the camera module 1880 or the electronic device 1901 including the same. Alternatively, the operation characteristics of the image sensor 1000 can be controlled (adjustment of read-out timing, etc.) to compensate for the negative effects of movement. The image stabilizer 1940 detects the movement of the camera module 1880 or the electronic device 1801 using a gyro sensor (not shown) or an acceleration sensor (not shown) disposed inside or outside the camera module 1880. You can. The image stabilizer 1940 may be implemented optically.

The memory 1950 may store part or all data of the image acquired through the image sensor 1000 for the next image processing task. For example, when multiple images are acquired at high speed, the acquired original data (Bayer-Patterned data, high-resolution data, etc.) is stored in the memory 1950, only the low-resolution images are displayed, and then the selected (user selection, etc.) It can be used to ensure that the original data of the image is transmitted to the image signal processor 1960. The memory 1950 may be integrated into the memory 1830 of the electronic device 1801, or may be configured as a separate memory that operates independently.

The image signal processor 1960 may perform image processing on images acquired through the image sensor 1000 or image data stored in the memory 1950. Image processing includes depth map creation, 3D modeling, panorama creation, feature point extraction, image compositing, and/or image compensation (noise reduction, resolution adjustment, brightness adjustment, blurring, sharpening) , softening, etc.). The image signal processor 1960 may perform control (exposure time control, read-out timing control, etc.) on components (such as the image sensor 1000) included in the camera module 1880. Images processed by the image signal processor 1960 are stored back in the memory 1950 for further processing or stored in external components of the camera module 1880 (memory 1830, display unit 1860, electronics 1802). , electronic device 1804, server 1808, etc.). The image signal processor 1960 may be integrated into the processor 1820 or may be configured as a separate processor that operates independently from the processor 1820. If the image signal processor 1960 is configured as a separate processor from the processor 1820, the image processed by the image signal processor 1960 undergoes additional image processing by the processor 1820 and then is displayed on the display device 1860. It can be displayed through

The electronic device 1801 may include a plurality of camera modules 1880, each with different properties or functions. In this case, one of the plurality of camera modules 1880 may be a wide-angle camera and the other may be a telephoto camera. Similarly, one of the plurality of camera modules 1880 may be a front camera and the other may be a rear camera.

The image sensor 1000 according to embodiments includes a mobile phone or smartphone 2000 shown in FIG. 40, a tablet or smart tablet 2100 shown in FIG. 41, and a digital camera or camcorder 2200 shown in FIG. 42. , can be applied to the laptop computer 2300 shown in FIG. 43 or the television or smart television 2400 shown in FIG. 44. For example, the smartphone 2000 or smart tablet 2100 may include a plurality of high-resolution cameras each equipped with a high-resolution image sensor. Using high-resolution cameras, you can extract depth information of subjects in an image, adjust the outfocusing of an image, or automatically identify subjects in an image.

Additionally, the image sensor 1000 may be used in the smart refrigerator 2500 shown in FIG. 45, the security camera 2600 shown in FIG. 46, the robot 2700 shown in FIG. 47, and the medical camera 2800 shown in FIG. 48. It can be applied to etc. For example, the smart refrigerator 2500 can automatically recognize food in the refrigerator using an image sensor and inform the user of the presence or absence of specific food and the type of food received or shipped to the user through the smartphone. The security camera 2600 can provide ultra-high resolution images and, using high sensitivity, can recognize objects or people in the image even in a dark environment. The robot 2700 can provide high-resolution images when deployed at disaster or industrial sites that cannot be directly accessed by humans. The medical camera 2800 can provide high-resolution images for diagnosis or surgery and can dynamically adjust its field of view.

Additionally, the image sensor 1000 may be applied to the vehicle 2900 as shown in FIG. 49. The vehicle 2900 may include a plurality of vehicle cameras 2910, 2920, 2930, and 2940 arranged at various locations. Each vehicle camera 2910, 2920, 2930, and 2940 may include an image sensor according to an embodiment. The vehicle 2900 can provide the driver with various information about the inside or surroundings of the vehicle 2900 using a plurality of vehicle cameras 2910, 2920, 2930, and 2940, and automatically recognizes objects or people in the image. It can provide information necessary for autonomous driving.

The image sensor having the above-described color separation lens array and the electronic device including the same have been described with reference to the embodiment shown in the drawings, but this is merely an example, and various modifications can be made by those skilled in the art. and other equivalent embodiments are possible. Therefore, the disclosed embodiments should be considered from an illustrative rather than a restrictive perspective. The scope of rights is indicated in the patent claims, not the foregoing description, and all differences within the equivalent scope should be interpreted as being included in the scope of rights.

110.....Sensor board
111, 112, 113, 114....light sensing cell
120....Spacer layer
121.....Dielectric layer
130.....Color separation lens array
140.....Color filter layer
141, 142, 143.....Color filter
150....Planar nano-optical microlens array
151.....Plane nano-optical microlens
160.....Convex microlens array
161.....Convex microlens
170.....Transparent dielectric layer
1000.....Image sensor
1010.....Timing controller
1020.....Row Decoder
1030.....Output circuit
1100.....pixel array

Claims (29)

A sensor substrate including a plurality of light-sensing cells that detect light; and
It includes a planar nano-optical microlens array including a plurality of planar nano-optical microlenses having a nano-pattern structure that focuses light on a corresponding photo-sensing cell among the plurality of photo-sensing cells,
Each planar nano-optical microlens includes a high refractive index nanostructure made of a dielectric material with a relatively high refractive index and a low refractive index structure made of a dielectric material with a relatively low refractive index,
The effective refractive index of the planar nano-optical microlens, which is determined by the ratio of the high refractive index nanostructure to the low refractive index structure, is highest in the refractive index peak area of the planar nano-optical microlens and gradually lowers around the refractive index peak area,
At the periphery of the planar nano-optic microlens array, the planar nano-optic microlenses have an asymmetric effective refractive index distribution wherein the effective refractive index distribution on the first side of the refractive index peak region is different from the effective refractive index distribution on the second side of the index peak region. and wherein the first side of the refractive index peak area is closer to the center of the planar nano-optical microlens array than the second side of the refractive index peak area. According to claim 1,
At the periphery of the planar nano-optical microlens array, the refractive index peak area of the planar nano-optical microlens is located away from the center of the planar nano-optical microlens toward the center of the planar nano-optic microlens array. According to clause 2,
At the periphery of the planar nano-optical microlens array, the distance between the refractive index peak area of the planar nano-optic microlens and the center of the planar nano-optic microlens is between the planar nano-optic microlens and the center of the planar nano-optic microlens array. The image sensor gets bigger as the distance increases. According to claim 1,
The peripheral planar nano-optical microlens has a first edge and a second edge opposite the first edge, the first edge being closer to the center of the planar nano-optical microlens array than the second edge,
The image sensor, wherein the slope of the effective refractive index distribution between the first edge and the refractive index peak area is greater than the slope of the effective refractive index distribution between the second edge and the refractive index peak area. According to clause 4,
The planar nano-optical microlens array includes a first planar nano-optical microlens and a second planar nano-optical microlens disposed at the periphery of the planar nano-optical microlens array,
The distance between the second planar nano-optical microlens and the center of the planar nano-optical microlens array is greater than the distance between the first planar nano-optical microlens and the center of the planar nano-optical microlens array,
The slope of the effective refractive index distribution between the first edge of the second planar nano-optical microlens and the refractive index peak area of the second planar nano-optical microlens is the first edge of the first planar nano-optical microlens and the first plane An image sensor that is greater than the slope of the effective refractive index distribution between the refractive index peak regions of the nano-optical microlens. According to clause 5,
The slope of the effective refractive index distribution between the second edge of the second planar nano-optical microlens and the refractive index peak area of the second planar nano-optical microlens is the second edge of the first planar nano-optical microlens and the first plane. An image sensor that is smaller than the slope of the effective refractive index distribution between the refractive index peak regions of a nano-optical microlens. According to claim 1,
Each planar nano-optical microlens has a first region having the highest effective refractive index, a second region surrounding the first region and having a lower effective refractive index than the first region, and a second region surrounding the second region and having an effective refractive index lower than the second region. An image sensor comprising a third region having a low refractive index. According to claim 1,
At the center of the planar nano-optical microlens array, the refractive index peak area of the planar nano-optical microlens is located at the center of the planar nano-optical microlens, and the planar nano-optical microlens has an effective refractive index distribution symmetrical about the center. Having an image sensor. According to claim 1,
At the periphery of the planar nano-optical microlens array, boundaries between the planar nano-optic microlenses coincide with boundaries between corresponding photo-sensing cells. According to claim 1,
At the periphery of the planar nano-optical microlens array, each planar nano-optical microlens is positioned shifted toward the center of the planar nano-optic microlens array with respect to the corresponding photo-sensing cells. According to claim 10,
At the periphery of the planar nano-optical microlens array, the distance that each planar nano-optic microlens is shifted toward the center of the planar nano-optic microlens array becomes larger as the distance from the center of the planar nano-optic microlens array increases. sensor. According to claim 10,
An image sensor, wherein the total area of the planar nano-optical microlens array is smaller than the total area of the sensor substrate. According to claim 1,
Each planar nano-optical microlens includes a plurality of high refractive index nanostructures having a nanopost shape, and the ratio of the area occupied by the plurality of high refractive index nanostructures to unit area is the highest in the refractive index peak area, an image sensor . According to claim 13,
An image sensor, wherein a high refractive index nanostructure with the largest width or diameter among the plurality of high refractive index nanostructures is disposed at the refractive index peak area. According to claim 14,
The plurality of high refractive index nanostructures include a first high refractive index nanostructure closer to the center of the planar nano-optical microlens array with respect to the high refractive index nanostructure with the largest width or diameter, and a high refractive index nanostructure with the largest width or diameter. comprising a second high refractive index nanostructure that is farther from the center of the planar nano-optical microlens array with respect to the structure,
The first high refractive index nanostructure and the second high refractive index nanostructure are arranged adjacent to the high refractive index nanostructure with the largest width or diameter,
The image sensor wherein the first width or diameter of the first high refractive index nanostructure is different from the second width or diameter of the second high refractive index nanostructure. According to claim 15,
The image sensor wherein the first width or diameter of the first high refractive index nanostructure is smaller than the second width or diameter of the second high refractive index nanostructure. According to claim 16,
The first pitch between the high refractive index nanostructure with the largest width or diameter and the first high refractive index nanostructure is the same as the second pitch between the high refractive index nanostructure with the largest width or diameter and the 21 high refractive index nanostructures. , image sensor. According to claim 14,
At the periphery of the planar nano-optical microlens array, the planar nano-optical microlens includes a plurality of high refractive index nanostructures, and the plurality of high refractive index nanostructures are aligned with the high refractive index nanostructure having the largest width or diameter. A first high refractive index nanostructure closer to the center of the planar nano-optical microlens array and a second high refractive index nanostructure further from the center of the planar nano-optical microlens array for the high refractive index nanostructure with the largest width or diameter. Includes,
The first high refractive index nanostructure and the second high refractive index nanostructure are arranged adjacent to the high refractive index nanostructure with the largest width or diameter,
The first width or diameter of the first high refractive index nanostructure is the same as the second width or diameter of the second high refractive index nanostructure,
The first pitch between the high refractive index nanostructure with the largest width or diameter and the first high refractive index nanostructure is smaller than the second pitch between the high refractive index nanostructure with the largest width or diameter and the 21 high refractive index nanostructures. , image sensor. According to claim 1,
Each planar nano-optical microlens includes a plurality of high-refractive-index nanostructures and a plurality of low-refractive-index structures arranged alternately, and the radial width of the high-refractive-index nanostructure is largest at the refractive index peak area. According to claim 1,
An image sensor, wherein each planar nano-optical microlens includes one low-refractive-index nanostructure in the form of a plate and a plurality of high-refractive-index structures in the form of holes. According to claim 1,
Each planar nano optical microlens includes a first layer and a second layer stacked on the first layer, and the pattern of the high refractive index nanostructures and the low refractive index structures of the first layer is the high refractive index nanostructure of the second layer. An image sensor with a different pattern from the structure and the low refractive index structure. According to claim 21,
In the refractive index peak area of each planar nano optical microlens, the high refractive index nanostructures in the first layer and the second layer have the same width, and in the area away from the refractive index peak area, the width of the high refractive index nanostructure in the second layer is An image sensor that is smaller than the width of the high refractive index nanostructure of this first layer. According to claim 1,
An image sensor further comprising a convex microlens disposed above each planar nano-optical microlens. According to clause 23,
At the center of the planar nano-optical microlens array, the refractive index peak areas of the corresponding planar nano-optical microlenses and the optical axes of the convex microlenses are aligned to coincide with each other. According to clause 23,
At the periphery of the planar nano-optic microlens array, the convex microlenses are shifted relative to the corresponding planar nano-optic microlenses toward the center of the planar nano-optic microlens array. According to claim 1,
The image sensor further includes a transparent dielectric layer disposed between the sensor substrate and the planar nano-optical microlens array and having a thickness that increases from the center of the planar nano-optical microlens array toward the periphery. According to claim 1,
It further includes a color filter layer disposed on the sensor substrate, wherein the color filter layer includes a plurality of color filters that transmit only light in a specific wavelength band and absorb or reflect light in other wavelength bands,
An image sensor, wherein the planar nano-optical microlens array is disposed on the color filter layer. An image sensor that converts optical images into electrical signals; and
A processor that controls the operation of the image sensor and stores and outputs signals generated by the image sensor,
The image sensor is:
A sensor substrate including a plurality of light-sensing cells that detect light; and
It includes a planar nano-optical microlens array including a plurality of planar nano-optical microlenses having a nano-pattern structure that focuses light on a corresponding photo-sensing cell among the plurality of photo-sensing cells,
Each planar nano-optical microlens includes a high refractive index nanostructure made of a dielectric material with a relatively high refractive index and a low refractive index structure made of a dielectric material with a relatively low refractive index,
The effective refractive index of the planar nano-optical microlens, which is determined by the ratio of the high refractive index nanostructure to the low refractive index structure, is highest in the refractive index peak area of the planar nano-optical microlens and gradually lowers around the refractive index peak area,
At the periphery of the planar nano-optic microlens array, the planar nano-optic microlenses have an asymmetric effective refractive index distribution wherein the effective refractive index distribution on the first side of the refractive index peak region is different from the effective refractive index distribution on the second side of the index peak region. wherein the first side of the refractive index peak region is closer to the center of the planar nano-optical microlens array than the second side of the refractive index peak region. Includes a pixel array,
The pixel array is:
A sensor substrate including a plurality of light-sensing cells that detect light;
a color filter layer disposed on the sensor substrate and including a plurality of color filters that transmit light in a specific wavelength band and absorb or reflect light in wavelength bands other than the specific wavelength band; and
A planar nano-optical microlens array disposed on the color filter layer and including a plurality of planar nano-optical microlenses having a nano-pattern structure that focuses light on a corresponding photo-sensing cell among the plurality of photo-sensing cells. And
Each planar nano-optical microlens includes a high refractive index nanostructure made of a dielectric material with a relatively high refractive index and a low refractive index structure made of a dielectric material with a relatively low refractive index,
The effective refractive index of the planar nano-optical microlens, which is determined by the ratio of the high refractive index nanostructure to the low refractive index structure, is highest in the refractive index peak area of the planar nano-optical microlens and gradually lowers around the refractive index peak area,
At the center of the planar nano-optical microlens array, the planar nano-optical microlens has a symmetrical effective refractive index distribution,
At the periphery of the planar nano-optic microlens array, the planar nano-optic microlenses have an asymmetric effective refractive index distribution wherein the effective refractive index distribution on the first side of the refractive index peak region is different from the effective refractive index distribution on the second side of the index peak region. and wherein the first side of the refractive index peak area is closer to the center of the planar nano-optical microlens array than the second side of the refractive index peak area.

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