Image sensor with color separation lens array and electronic device including the same

Abstract

To provide an image sensor including a color separation lens array.SOLUTION: An image sensor includes a sensor substrate including a first pixel for sensing first wavelength light and a second pixel for sensing second wavelength light, and a color separation lens array for condensing, among the incident light, the first wavelength light to the first pixel and the second wavelength light to the second pixel. The color separation lens array includes a first pixel corresponding region disposed at a position corresponding to the first pixel and a second pixel corresponding region disposed at a position corresponding to the second pixel. The phase difference between the first wavelength light passing the center of the first pixel corresponding region and the first wavelength light passing the center of the second pixel corresponding region is also different from the phase difference between the second wavelength light passing the center of the first pixel corresponding region and the second wavelength light passing the center of the second pixel corresponding region.SELECTED DRAWING: Figure 7A

Description

[Technical Field]

[0001] The present invention relates to an image sensor having a color separation lens array capable of separating and focusing incident light according to wavelength, and an electronic device including the image sensor. [Background technology]

[0002] Typically, image sensors use color filters to detect the color of incident light. However, color filters absorb light of colors other than the color of the filter, resulting in reduced light utilization efficiency. For example, when using an RGB color filter, only one-third of the incident light is transmitted and the remaining two-thirds is absorbed, resulting in a light utilization efficiency of only about 33%. Therefore, in color display devices and color image sensors, most of the light loss occurs in the color filters. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention provides an image sensor and an electronic device including the image sensor, which have improved light utilization efficiency and autofocusing capability by using a color separation lens array that can separate and focus incident light according to wavelength. [Means for solving the problem]

[0004] An image sensor according to one embodiment includes a sensor substrate including first pixels for sensing light of a first wavelength and second pixels for sensing light of a second wavelength, and a color separation lens array for focusing light of the first wavelength onto the first pixels and light of the second wavelength onto the second pixels, the color separation lens array including first pixel corresponding regions arranged at positions corresponding to the first pixels and second pixel corresponding regions arranged at positions corresponding to the second pixels, and a phase difference between the first wavelength light passing through the center of the first pixel corresponding region and the first wavelength light passing through the center of the second pixel corresponding region is different from a phase difference between the second wavelength light passing through the center of the first pixel corresponding region and the second wavelength light passing through the center of the second pixel corresponding region.

[0005] According to another embodiment, the image sensor includes a sensor substrate including first pixels for sensing light of a first wavelength and second pixels for sensing light of a second wavelength; and a color separation lens array including a first wavelength light focusing region for focusing light of the first wavelength onto the first pixel and a second wavelength light focusing region for focusing light of the second wavelength onto the second pixel, wherein the area of ​​the first wavelength light focusing region is larger than the area of ​​the first pixel, the area of ​​the second wavelength light focusing region is larger than the area of ​​the second pixel, and a first focal length of the first wavelength light relative to the first wavelength light focusing region is the same as a second focal length of the second wavelength light relative to the second wavelength light focusing region.

[0006] According to yet another embodiment, the image sensor includes: a sensor substrate including first pixels for sensing first wavelength light and second pixels for sensing second wavelength light; and a color separation lens array including first wavelength light focusing regions for focusing first wavelength light onto the first pixels and second wavelength light focusing regions for focusing second wavelength light onto the second pixels; wherein the area of ​​the first wavelength light focusing regions is larger than the area of ​​the first pixels and the area of ​​the second wavelength light focusing regions is larger than the area of ​​the second pixels; the first wavelength light passing through the first wavelength light focusing regions has a phase distribution that is largest at the center of the first wavelength light focusing regions and decreases in a direction away from the center; and the second wavelength light passing through the second wavelength light focusing regions has a phase distribution that is largest at the center of the second wavelength light focusing regions and decreases in a direction away from the center, and the phase decrease rates of the first wavelength light and the second wavelength light are different from each other.

[0007] According to yet another embodiment, the image sensor includes a sensor substrate including first pixels for sensing first wavelength light and second pixels for sensing second wavelength light; and a color separation lens array including a first wavelength light focusing region for focusing first wavelength light of incident light onto the first pixel and a second wavelength light focusing region for focusing second wavelength light onto the second pixel; wherein a phase difference between the first wavelength light passing through the center of the first wavelength light focusing region and the first wavelength light passing through a position spaced apart from the center of the first wavelength light focusing region by about half the pixel pitch of the sensor substrate is different from a phase difference between the second wavelength light passing through the center of the second wavelength light focusing region and the second wavelength light passing through a position spaced apart from the center of the second wavelength light focusing region by about half the pixel pitch of the sensor substrate.

[0008] According to one embodiment, an electronic device 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 the signal generated by the image sensor. The image sensor includes: a sensor substrate including first pixels for sensing light of a first wavelength and second pixels for sensing light of a second wavelength; and a color separation lens array including a first wavelength light focusing region for focusing light of the first wavelength onto the first pixel and a second wavelength light focusing region for focusing light of the second wavelength onto the second pixel; wherein the area of ​​the first wavelength light focusing region is larger than the area of ​​the first pixel, the area of ​​the second wavelength light focusing region is larger than the area of ​​the second pixel, and a first focal length of the first wavelength light by the first wavelength light focusing region is equal to a second focal length of the second wavelength light by the second wavelength light focusing region. [Effects of the Invention]

[0009] According to the present invention, the color separation lens array can separate and focus incident light according to wavelength without absorbing or blocking the incident light, thereby improving the light utilization efficiency of the image sensor. Furthermore, the phase profile of the light-focusing regions included in the color separation lens array can be adjusted differently depending on the wavelength, thereby improving the autofocusing performance. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a block diagram illustrating an image sensor according to an embodiment. [Figure 2A] 1 is a diagram illustrating various pixel arrangements of a pixel array of an image sensor; [Figure 2B] 1 is a diagram illustrating various pixel arrangements of a pixel array of an image sensor; [Figure 2C] 1 is a diagram illustrating various pixel arrangements of a pixel array of an image sensor; [Figure 3A] 1 is a conceptual diagram showing the general structure and operation of a color separation lens array according to an embodiment. [Figure 3B] 1 is a conceptual diagram showing the general structure and operation of a color separation lens array according to an embodiment. [Figure 4A] 1 is a diagram for explaining the relationship between the wavelength and phase distribution of light and the focal length. [Figure 4B] 1 is a diagram for explaining the relationship between the wavelength and phase distribution of light and the focal length. [Figure 5A] 2A-2C are schematic cross-sectional views taken at different cross sections of a pixel array of an image sensor according to one embodiment; [Figure 5B] 2A-2C are schematic cross-sectional views taken at different cross sections of a pixel array of an image sensor according to one embodiment; [Figure 6A] FIG. 2 is a plan view schematically showing an arrangement of pixels in a pixel array. [Figure 6B] 10 is a plan view illustrating an example of a form in which a plurality of nanoposts are arranged in a plurality of regions of a color separation lens array. FIG. [Figure 6C] FIG. 6C is an enlarged plan view showing a portion of FIG. 6B in detail. [Figure 7A] 6C is a diagram showing the phase distribution of green light and blue light that have passed through the color separation lens array, taken along line II' of FIG. 6B. [Figure 7B] 10 is a diagram showing the phase of green light at the center of a pixel corresponding area that has passed through a color separation lens array. [Figure 7C] 10 is a diagram showing the phase of blue light at the center of a pixel-corresponding area that has passed through a color separation lens array. [Figure 7D]10 is a diagram illustrating an example of a traveling direction of green light incident on a first green light collecting region; [Figure 7E] 10 is a diagram illustrating an example of an array of first green light collecting regions. [Figure 7F] 10 is a diagram illustrating an example of a traveling direction of blue light incident on a blue light collecting region; [Figure 7G] 1 is a diagram illustrating an example of an array of blue light collecting regions. [Figure 8A] 6C is a diagram showing the phase distribution of red and green light that has passed through the color separation lens array, taken along line II-II' in FIG. 6B. [Figure 8B] 10 is a diagram showing the phase of red light at the center of a pixel corresponding area that has passed through a color separation lens array. [Figure 8C] 10 is a diagram showing the phase of green light at the center of a pixel corresponding area that has passed through a color separation lens array. [Figure 8D] 10 is a diagram illustrating an example of a traveling direction of red light incident on a red light collecting region; [Figure 8E] 10 is a diagram showing an example of an array of red light collecting regions. [Figure 8F] 10 is a diagram illustrating an example of a traveling direction of green light incident on a second green light collecting region; [Figure 8G] 10 is a diagram illustrating an example of an array of second green light collecting regions. [Figure 9A] 10 is a diagram for explaining the relationship between the focal length of a light-collecting region and an autofocus function. [Figure 9B] 10 is a diagram for explaining the relationship between the focal length of a light-collecting region and an autofocus function. [Figure 9C] 10 is a diagram for explaining the relationship between the focal length of a light-collecting region and an autofocus function. [Figure 10] 1 is a block diagram that schematically illustrates an electronic device including an image sensor according to an embodiment. [Figure 11] FIG. 11 is a block diagram illustrating the camera module of FIG. [Figure 12] 1 is a diagram illustrating various examples of electronic devices to which an image sensor according to an embodiment is applied; [Figure 13] 1 is a diagram illustrating various examples of electronic devices to which an image sensor according to an embodiment is applied; [Figure 14] 1 is a diagram illustrating various examples of electronic devices to which an image sensor according to an embodiment is applied; [Figure 15] 1 is a diagram illustrating various examples of electronic devices to which an image sensor according to an embodiment is applied; [Figure 16] 1 is a diagram illustrating various examples of electronic devices to which an image sensor according to an embodiment is applied; [Figure 17] 1 is a diagram illustrating various examples of electronic devices to which an image sensor according to an embodiment is applied; [Figure 18] 1 is a diagram illustrating various examples of electronic devices to which an image sensor according to an embodiment is applied; [Figure 19] 1 is a diagram illustrating various examples of electronic devices to which an image sensor according to an embodiment is applied; [Figure 20] 1 is a diagram illustrating various examples of electronic devices to which an image sensor according to an embodiment is applied; [Figure 21] 1 is a diagram illustrating various examples of electronic devices to which an image sensor according to an embodiment is applied; DETAILED DESCRIPTION OF THE INVENTION

[0011] 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 accompanying drawings. The described embodiments are merely exemplary, and various modifications are possible from such 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.

[0012] Hereinafter, the term "upper" or "above" includes not only what is in contact and directly above / below / left / right, but also what is not in contact and is above / below / left / right.

[0013] Terms such as first and second may be used to describe various components, but are used only to distinguish one component from another, and such terms do not limit the material or structural differences of the components.

[0014] The singular expressions include the plural expressions unless the context clearly dictates otherwise. Furthermore, when a part "comprises" a certain element, this does not mean excluding other elements, but means that other elements may also be included, unless otherwise specified to the contrary.

[0015] In addition, terms such as "unit" and "module" used in the specification refer to a unit that processes one or more functions or operations, and may be realized by hardware or software, or by a combination of hardware and software.

[0016] The use of "the" and similar directives also applies to both the singular and the plural.

[0017] The steps constituting the method may be performed in any suitable order unless expressly stated to be in the order of description. Furthermore, the use of all exemplary terms (such as, for example, etc.) is merely for the purpose of explaining the technical idea in detail, and does not limit the scope of the right, except as limited by the claims.

[0018] 1 is a schematic block diagram of an image sensor according to an embodiment. Referring to FIG. 1, an image sensor 1000 includes 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.

[0019] 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 a row address signal output from the timing controller 1010. The output circuit 1030 outputs a photo-sensing signal in units of columns from a plurality of pixels arranged along the selected row. To this end, the output circuit 1030 includes a column decoder and an analog-to-digital converter (ADC). For example, the output circuit 1030 includes a plurality of ADCs arranged for each column between the column decoder and the pixel array 1100, or a single ADC arranged at the output end of the column decoder. The timing controller 1010, the row decoder 1020, and the output circuit 1030 may be implemented on a single chip or on separate chips. A processor for processing the image signal output via the output circuit 1030 may also be implemented on a single chip together with the timing controller 1010, the row decoder 1020, and the output circuit 1030.

[0020] The pixel array 1100 includes a plurality of pixels that sense light of different wavelengths. The pixel arrangement may be implemented in various ways. For example, Figures 2A to 2C illustrate various pixel arrangements of the pixel array 1100 of the image sensor 1000.

[0021] First, FIG. 2A shows a Bayer pattern commonly used in image sensors 1000. Referring to FIG. 2A, one unit pattern includes four quadrant regions, and the first through fourth quadrants are blue, green, red, and green pixels B, G, R, and G, respectively. Such unit patterns are two-dimensionally repeated along a first direction (X direction) and a second direction (Y direction). That is, within a 2×2 array of unit patterns, two green pixels G are arranged diagonally on one side, and one blue pixel B and one red pixel R are arranged diagonally on the other side. The pixel arrangement as a whole is repeated along the second direction, with 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 second row in which a plurality of red pixels R and a plurality of green pixels G are alternately arranged along the first direction.

[0022] The pixel array 1100 may be arranged in various ways other than the Bayer pattern. For example, referring to FIG. 2B, a CYGM type arrangement is possible in which a magenta pixel M, a cyan pixel C, a yellow pixel Y, and a green pixel G form one unit pixel pattern. Referring to FIG. 2C, a RGBW type arrangement is also possible in which a green pixel G, a red pixel R, a blue pixel B, and a white pixel W form one unit pattern. Although not shown, the unit pattern may have a 3x2 array shape. The pixels of the pixel array 1100 may also be arranged in various ways depending on the color characteristics of the image sensor 1000. Hereinafter, the pixel array 1100 of the image sensor 1000 will be described as having a Bayer pattern, but the operating principle can also be applied to pixel arrays of other types than the Bayer pattern.

[0023] The pixel array 1100 of the image sensor 1000 may include a color separation lens array that focuses light of a color corresponding to a particular pixel. Figures 3A and 3B are conceptual diagrams showing the structure and operation of a color separation lens array.

[0024] Referring to FIG. 3A, a color separating lens array (CSLA) includes a plurality of nanoposts NP that change the phase of incident light Li differently depending on the incident position. The color separating lens array 1100 can be divided in various ways. For example, a first wavelength light L included in the incident light Li is divided into two wavelengths. λ1 a first pixel corresponding region R1 corresponding to the first pixel PX1 where the second wavelength light L included in the incident light Li is collected; λ2 The first and second pixel-corresponding regions R1 and R2 may each include one or more nanoposts NP and may be arranged to face the first and second pixels PX1 and PX2, respectively. As another example, the color separation lens array 1100 may be configured to separate the first wavelength light L λ1 The first wavelength light collecting region L1 collects the second wavelength light L λ2 The first wavelength light collecting region L1 and the second wavelength light collecting region L2 may be partitioned into a second wavelength light collecting region L2 that collects light at the second pixel PX2. The first wavelength light collecting region L1 and the second wavelength light collecting region L2 may be partially overlapped.

[0025] The color separation lens array CSLA separates the first and second wavelength lights L included in the incident light Li. λ1 , L λ2 The first wavelength light L λ1 is focused on the first pixel PX1, and the second wavelength light L λ2 can be focused on the second pixel PX2.

[0026] For example, referring to FIG. 3B, the color separation lens array CSLA separates the first wavelength light L from the first wavelength light L at a position immediately after passing through the color separation lens array CSLA, i.e., at the position of the lower surface of the color separation lens array CSLA. λ1 has a first phase distribution PP1, and the second wavelength light L λ2 has a second phase distribution PP2, and the first and second wavelength light L λ1 , L λ2 Specifically, the first wavelength light L passing through the color separation lens array CSLA is focused onto the first and second pixels PX1 and PX2. λ1may have a phase distribution PP1 that is greatest at the center of the first pixel corresponding region R1 and decreases in the direction away from the center of the first pixel corresponding region R1, i.e., in the direction of the second pixel corresponding region R2. Such a phase distribution is similar to the phase distribution of light that passes through a convex lens, for example, a microlens with a convex center located in the first-wavelength light collecting region L1, and converges to one point. λ1 The second wavelength light L that has passed through the color separation lens array CSLA can be collected at the first pixel PX1. λ2 has a phase distribution PP2 that is greatest at the center of the second pixel corresponding region R2 and decreases in the direction away from the center of the second pixel corresponding region R2, i.e., in the direction of the first pixel corresponding region R1, and the second wavelength light L λ2 can be focused on the second pixel PX2.

[0027] Since the refractive index of a material varies depending on the wavelength of light to which it responds, as shown in FIG. 3B, the color separation lens array CSLA separates the first and second wavelength lights L λ1 , L λ2 That is, even if the material is the same, the refractive index varies depending on the wavelength of light that reacts with the material, and the phase delay that the light experiences when passing through the material also varies depending on the wavelength, so different phase distributions can be formed for each wavelength. For example, λ1 and the refractive index for the second wavelength light L λ2 The refractive indexes of the first wavelength light L that has passed through the first pixel corresponding region R1 are different from each other. λ1 and the phase delay experienced by the second wavelength light L passing through the first pixel corresponding region R1. λ2 Therefore, if the color separation lens array CSLA is designed taking into consideration the characteristics of light, the first and second wavelength lights L λ1 , L λ2 can provide different phase distributions for

[0028] The color separation lens array CSLA separates the first and second wavelength light L λ1 , L λ2The nanopost NPs are arranged according to a specific rule so that they have first and second phase distributions PP1 and PP2, respectively. Here, the rule applies to parameters such as the shape, size (width, height), spacing, and arrangement of the nanopost NPs, and these parameters can be determined by the phase profile to be realized through the color separation lens array CSLA.

[0029] The arrangement of the nanoposts NPs in the first pixel-corresponding region R1 and the second pixel-corresponding region R2 are different from each other, i.e., the size, shape, spacing, and / or arrangement of the nanoposts NPs in the first pixel-corresponding region R1 are different from the size, shape, spacing, and / or arrangement of the nanoposts NPs in the second pixel-corresponding region R2.

[0030] The nanopost NP may have a cross-sectional diameter of subwavelength. Here, subwavelength refers to a wavelength smaller than the wavelength band of the light to be split. The nanopost NP may have a dimension smaller than the shorter of the first and second wavelengths, for example. When the incident light Li is visible light, the cross-sectional diameter of the nanopost NP may be, for example, smaller than 400 nm, 300 nm, or 200 nm. On the other hand, the height of the nanopost NP may be 500 nm to 1500 nm, and may be greater than the cross-sectional diameter. Although not shown, the nanopost NP may also be formed by combining two or more posts stacked in the height direction (Z direction).

[0031] Nanopost NPs can be made of materials with a higher refractive index than the surrounding material. For example, nanopost NPs include c-Si, p-Si, a-Si, III-V compound semiconductors (e.g., GaP, GaN, GaAs), SiC, TiO2, SiN, and / or combinations thereof. Nanopost NPs with a refractive index different from that of the surrounding material can change the phase of light passing through the nanopost NP. This is due to the phase delay (phase profile) caused by the subwavelength shape of the nanopost NPs, and the degree of phase delay is determined by the detailed shape, arrangement, etc. of the nanopost NPs. The material surrounding the nanopost NPs can be made of a dielectric material with a lower refractive index than the nanopost NPs. For example, the surrounding material can include SiO2 or air.

[0032] The first wavelength λ1 and the second wavelength λ2 may be, but are not limited to, infrared and visible wavelength bands, and operation at various wavelengths is possible depending on the arrangement of the array of the nanopost NPs. Also, although an example is shown in which two wavelengths are branched and focused, incident light can be branched and focused in three or more directions depending on the wavelength.

[0033] Although the color separation lens array CSLA has been described as having one layer, the color separation lens array CSLA may also have a structure in which multiple layers are stacked together. For example, one layer may be designed to focus visible light on a specific pixel, and a second layer may be designed to focus infrared light on another pixel.

[0034] 4A and 4B are diagrams for explaining the relationship between the wavelength and phase distribution of light and the focal length.

[0035] 4A illustrates the first through third focal lengths f1, f2, and f3 of three different wavelengths of light having the same phase distribution. Specifically, the focal lengths for 540 nm, 450 nm, and 630 nm wavelengths are illustrated when the three wavelengths have a phase distribution that is 2π at the center of each wavelength-focusing region L1, L2, and L3 immediately after passing through the first through third wavelength-focusing regions L1, L2, and L3 of the color separation lens array and decreases to π as they move away from the center. Specifically, the 540 nm light is focused at a first focal length f1 due to a first phase distribution PPa that decreases from 2π to π. The 450 nm light is focused at a second focal length f2 (longer than the first focal length f1) due to a second phase distribution PPb (identical to the first phase distribution PPa). The 630 nm light is focused at a third focal length f3 (shorter than the first focal length f1) due to a third phase distribution PPc (identical to the first phase distribution PPa). That is, when the phase distribution is the same, the focal length is inversely proportional to the wavelength. Therefore, in order for each of the light-collecting regions L1, L2, and L3 to have the same focal length for incident light of different wavelengths, the color separation lens array 130 must provide a phase distribution with different phase reduction rates in the X direction for each wavelength.

[0036] FIG. 4B is a diagram illustrating a phase distribution of a light-collecting region that causes incident light beams with different wavelengths to have the same focal length.

[0037] 4B, phase distributions PPa, PPb', and PPc' of three different wavelengths of light having the same focal length are shown. The first phase distribution PPa of the 540 nm wavelength light in FIG. 4B is the same as that described in FIG. 4A, and the 540 nm wavelength light has a first focal length f1.

[0038] The 450 nm light in FIG. 4B may have a second' focal length f2' that is shorter than the second focal length f2 in FIG. 4A. To reduce the focal length, the second' phase distribution PPb' also has a larger phase decrease rate in the X direction compared to the second phase distribution PPb in FIG. 4A. That is, the second phase distribution PPb in FIG. 4A is 2π at the center of the second light-collecting region L2 and decreases by π to π away from the center, while the second' phase distribution PPb' in FIG. 4B is 2π at the center of the second light-collecting region L2 and decreases by 1.2π to 0.8π away from the center. Because the decrease rate of the second' phase distribution PPb' is larger, the second' focal length f2' of the second' wavelength light-collecting region L2' in FIG. 4B is shorter, and the second' focal length f2' can be designed to be the same as the first focal length f1.

[0039] On the other hand, the 630 nm light in FIG. 4B can have a third' focal length f3' that is longer than the third focal length f3 in FIG. 4A. To increase the focal length, the phase falloff rate in the X direction at the center of the light-collecting region is reduced. For example, the third' phase distribution PPc' also has a smaller phase falloff rate than the third phase distribution PPc in FIG. 4A. That is, the third phase distribution PPc in FIG. 4A is 2π at the center of the third wavelength light-collecting region L3 and decreases by π to π away from the center. Meanwhile, the third' phase distribution PPc' in FIG. 4B is 2π at the center of the third wavelength light-collecting region L3 and decreases by 0.8π to 1.2π away from the center. Since the phase reduction rate of the third' phase distribution PPc' is smaller than that of the third phase distribution PPc, the third' focal length f3' of the third' wavelength focusing region L3' for the third wavelength light in Figure 4B becomes longer, and the third' focal length f3' can be designed to be the same as the first focal length f1.

[0040] An example in which the above-described color separation lens array 130 is applied to the pixel array 1100 of the image sensor 1000 will now be described in more detail.

[0041] Figures 5A and 5B are schematic cross-sectional views of different sections of a pixel array 1100 of an image sensor 1000 according to one embodiment, Figure 6A is a plan view schematically showing the arrangement of pixels in the pixel array 1100 of the image sensor 1000, Figure 6B is a plan view illustratively showing a form in which multiple nanoposts are arranged in multiple regions of a color separation lens array in the pixel array 1100 of the image sensor 1000, and Figure 6C is a plan view showing an enlarged and detailed portion of Figure 6B.

[0042] Referring to Figures 5A and 5B, the pixel array 1100 of the image sensor 1000 includes a sensor substrate 110 including a plurality of light-sensing pixels 111, 112, 113, and 114, a transparent spacer layer 120 disposed on the sensor substrate 110, and a color separation lens array 130 disposed on the spacer layer 120.

[0043] The sensor substrate 110 may include first green pixels 111, blue pixels 112, red pixels 113, and second green pixels 114 that convert light into electrical signals. The first green pixels 111 and blue pixels 112 are alternately arranged along a first direction (X direction). In a cross section at a different position in the Y direction, as shown in FIG. 5B, the red pixels 113 and second green pixels 114 are alternately arranged. FIG. 6A shows a pixel arrangement when the pixel array 1100 of the image sensor 1000 has a Bayer pattern arrangement as shown in FIG. 2A. Such an arrangement is for dividing incident light into unit patterns such as the Bayer pattern and sensing the light. For example, the first and second green pixels 111 and 114 may sense green light, the blue pixel 112 may sense blue light, and the red pixel 113 may sense red light. Although not shown, a separation layer for separating cells may be further formed at the boundaries between the cells.

[0044] 6A , some or all of the pixels 111, 112, 113, and 114 may include two or more photosensitive cells, and pixels including two or more photosensitive cells are also autofocus pixels. The autofocus pixels include, for example, 2 to 16 photosensitive cells. The logic circuit of the image sensor 1000 may implement an autofocus function of the image sensor 1000 and / or a camera device including the image sensor 1000 by using the difference between signals acquired from the photosensitive cells included in the autofocus pixel. The autofocus pixel includes an intra-pixel isolation layer for isolating the photosensitive cells so as to accurately calculate the difference between the output signals of two or more photosensitive cells included in one pixel. Since the photosensitive cells are isolated from each other by the intra-pixel isolation layer, they can output separate signals. In the embodiment of FIGS. 5A and 5B , the green, blue, and red pixels 111, 112, 113, and 114 each include two photosensitive cells. For example, the first green pixel 111 includes the 1-1st and 1-2nd green photosensitive cells 111a and 111b, the blue pixel 112 includes the 1st and 2nd blue photosensitive cells 112a and 112b, the red pixel 113 includes the 1st and 2nd red photosensitive cells 113a and 113b, and the second green pixel 114 includes the 2-1st and 2-2nd green photosensitive cells 114a and 114b.

[0045] 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 may be made of a material transparent to visible light, for example, a dielectric material having a refractive index lower than that of the nanopost NPs and low absorption in the visible light band, such as SiO2 or siloxane-based spin-on glass (SOG). The thickness h of the spacer layer 120 is h t -p≦h≦h t +p, where the theoretical thickness of the spacer layer 120 is h t can be expressed by the following Equation 1, where n is the refractive index of the spacer layer 120 for the wavelength λ0 and p is the pixel pitch.

[0046]

number

[0047] The theoretical thickness h of the spacer layer 120 t means the focal length at which light having a wavelength of λ0 is focused onto the upper surfaces of the pixels 111, 112, 113, and 114 by the color separation lens array 130. λ0 is also a wavelength that serves as a reference for determining the thickness h of the spacer layer 120, and the thickness of the spacer layer 120 can be designed based on 540 nm, which is the central wavelength of green light.

[0048] The color separation lens array 130 is supported by the spacer layer 120, is disposed between the nanopost NPs that change the phase of incident light, and includes a dielectric material with a lower refractive index than the nanopost NPs, such as air or SiO 2 .

[0049] 6B, the color separation lens array 130 may be divided into four regions 131, 132, 133, and 134 corresponding to the pixels 111, 112, 113, and 114 of FIG. 6A. The first green pixel-corresponding region 131 may correspond to the first green pixel 111 and be disposed above the first green pixel 111, the blue pixel-corresponding region 132 may correspond to the blue pixel 112 and be disposed above the blue pixel 112, the red pixel-corresponding region 133 may correspond to the red pixel 113 and be disposed above the red pixel 113, and the second green pixel-corresponding region 134 may correspond to the second green pixel 114 and be disposed above the second green pixel 114. That is, the pixel-corresponding regions 131, 132, 133, and 134 of the color separation lens array 130 may be disposed to face the pixels 111, 112, 113, and 114 of the sensor substrate 110. The pixel corresponding regions 131, 132, 133, and 134 may be two-dimensionally arranged along a first direction (X direction) and a second direction (Y direction) such that a first row in which the first green pixel corresponding regions and the blue pixel corresponding regions 131, 132 are alternately arranged and a second row in which the red pixel corresponding regions and the second green pixel corresponding regions 133, 134 are alternately arranged are alternately repeated. Like the sensor substrate 110, the color separation lens array 130 also includes a plurality of unit patterns arranged two-dimensionally, and each unit pattern includes pixel corresponding regions 131, 132, 133, and 134 arranged in a 2x2 configuration.

[0050] Meanwhile, the color separation lens array 130 can be divided into a green light focusing region that focuses green light, a blue light focusing region that focuses blue light, and a red light focusing region that focuses red light, as described in FIG. 3B.

[0051] The color separation lens array 130 includes nanopost NPs whose size, shape, spacing, and / or arrangement are determined so that green light is branched and focused at the first and second green pixels 111 and 114, blue light is branched and focused at the blue pixel 112, and red light is branched and focused at the red pixel 113. Meanwhile, the thickness (Z direction) of the color separation lens array 130 is similar to the height of the nanopost NPs and is also 500 nm to 1500 nm.

[0052] 6B, the pixel-corresponding regions 131, 132, 133, and 134 may include cylindrical nanopost NPs with circular cross sections, with nanopost NPs with different cross-sectional areas arranged in the center of each region, and nanopost NPs may also be arranged at the centers of inter-pixel boundaries and at intersections of pixel boundaries, with the cross-sectional areas of the nanopost NPs arranged at the inter-pixel boundaries being smaller than those arranged at the center of the pixels.

[0053] FIG. 6C shows in detail the arrangement of nanoposts NPs included in a portion of FIG. 6B, i.e., pixel-corresponding regions 131, 132, 133, and 134 that constitute the unit pattern. In FIG. 6C, the nanoposts NPs are labeled p1 through p9 according to their detailed positions. Referring to FIG. 6C, among the nanoposts NPs, nanopost p1 disposed at the center of the first green pixel-corresponding region 131 and nanopost p4 disposed at the center of the second green pixel-corresponding region 134 have larger cross-sectional areas than nanopost p2 disposed at the center of the blue pixel-corresponding region 132 and nanopost p3 disposed at the center of the red pixel-corresponding region 133, and the cross-sectional area of ​​nanopost p2 disposed at the center of the blue pixel-corresponding region 132 is larger than the cross-sectional area of ​​nanopost p3 disposed at the center of the red pixel-corresponding region 133. However, this is merely an example, and nanoposts NPs of various shapes, sizes, and arrangements may be used as needed.

[0054] The nanoposts NP provided in the first and second green pixel-corresponding regions 131 and 134 may have different distribution patterns in the first direction (X direction) and the second direction (Y direction). For example, the nanoposts NP arranged in the first and second green pixel-corresponding regions 131 and 134 may have different size arrangements in the first direction (X direction) and the second direction (Y direction). As shown in FIG. 6C , the cross-sectional area of ​​nanopost p5 located at the boundary between the first green pixel-corresponding region 131 and the adjacent blue pixel-corresponding region 132 in the first direction (X direction) is different from the cross-sectional area of ​​nanopost p6 located at the boundary between the first green pixel-corresponding region 131 and the adjacent red pixel-corresponding region 133 in the second direction (Y direction). Similarly, the cross-sectional area of ​​nanopost p7 located at the boundary between the second green pixel-corresponding region 134 and the adjacent red pixel-corresponding region 133 in the first direction (X direction) is different from the cross-sectional area of ​​nanopost p8 located at the boundary between the second green pixel-corresponding region 134 and the adjacent blue pixel-corresponding region 132 in the second direction (Y direction).

[0055] Meanwhile, the nanoposts NP arranged in the blue pixel corresponding region 132 and the red pixel corresponding region 133 may have a symmetrical distribution pattern along the first direction (X direction) and the second direction (Y direction). As shown in Figure 6C, among the nanoposts NP, nanopost p5 placed on the boundary between pixels adjacent to the blue pixel corresponding region 132 in the first direction (X direction) and nanopost p8 placed on the boundary between pixels adjacent to the blue pixel corresponding region 132 in the second direction (Y direction) have the same cross-sectional area. Also, in the red pixel corresponding region 133, nanopost p7 placed on the boundary between pixels adjacent to the first direction (X direction) and nanopost p6 placed on the boundary between pixels adjacent to the second direction (Y direction) have the same cross-sectional area.

[0056] On the other hand, the nanoposts p9 arranged at the four corners of each of the pixel corresponding regions 131, 132, 133, and 134, that is, at the positions where the four regions intersect, have the same cross-sectional area.

[0057] This distribution is due to the pixel arrangement of the Bayer pattern. The blue pixel 112 and the red pixel 113 are identical in that their adjacent pixels in the first direction (X direction) and the second direction (Y direction) are the green pixels 111 and 114, respectively. Meanwhile, the first green pixel 111 is different from the first green pixel 111 in that its adjacent pixel in the first direction (X direction) is the blue pixel 112 and its adjacent pixel in the second direction (Y direction) is the red pixel 113. The second green pixel 114 is different from the first green pixel 111 in that its adjacent pixel in the first direction (X direction) is the red pixel 113 and its adjacent pixel in the second direction (Y direction). The first and second green pixels 111 and 114 are identical to each other in that their four diagonally adjacent pixels are green pixels, and the blue pixel 112 is identical to each other in that its four diagonally adjacent pixels are red pixels 113. The red pixel 113 is identical to each other in that its four diagonally adjacent pixels are blue pixels 112. Therefore, the nanoposts NPs may be arranged in a 4-fold symmetry pattern in the blue and red pixel corresponding regions 132, 133 corresponding to the blue pixel 112 and the red pixel 113, and in a 2-fold symmetry pattern in the first and second green pixel corresponding regions 131, 134. In particular, the first and second green pixel corresponding regions 131, 134 are rotated 90° relative to each other.

[0058] 6B and 6C are depicted as having a symmetrical circular cross-sectional shape, some nanoposts have asymmetrical cross-sectional shapes. For example, the first and second green pixel corresponding regions 131 and 134 may employ nanoposts having asymmetrical cross-sectional shapes with different widths in the first direction (X direction) and the second direction (Y direction), while the blue and red pixel corresponding regions 132 and 133 may employ nanoposts having symmetrical cross-sectional shapes with the same widths in the first direction (X direction) and the second direction (Y direction).

[0059] The above-described arrangement rule of the nanoposts NPs is an example, and is not limited to the illustrated pattern.

[0060] 7A shows the phase distribution of green light and blue light that has passed through color separation lens array 130 along line I-I' in FIG. 6B, FIG. 7B shows the phase of green light that has passed through color separation lens array 130 at the centers of pixel-corresponding areas 131, 132, 133, and 134, and FIG. 7C shows the phase of blue light that has passed through color separation lens array 130 at the centers of pixel-corresponding areas 131, 132, 133, and 134. The phase distribution of the green light and blue light in FIG. 7A is similar to the phase distribution of the first and second wavelength light exemplarily described in FIG. 3B.

[0061] 7A and 7B, the green light passing through the color separation lens array 130 may have a phase distribution in which the phase is greatest at the center of the first green pixel corresponding region 131 and decreases in a direction away from the center of the first green pixel corresponding region 131. Specifically, immediately after passing through the color separation lens array 130, i.e., on the lower surface of the color separation lens array 130 or the upper surface of the spacer layer 120, the phase of the green light is greatest at the center of the first green pixel corresponding region 131 and gradually decreases concentrically with increasing distance from the center of the first green pixel corresponding region 131. The phase is minimum at the centers of the blue and red pixel corresponding regions 132 and 133 in the X and Y directions, and is minimum at the junction of the first green pixel corresponding region 131 and the second green pixel corresponding region 134 in the diagonal direction. If the phase of green light emitted from the center of first green pixel-corresponding region 131 is determined to be 2π, light with a phase of 0.9π to 1.1π can be emitted from the centers of blue and red pixel-corresponding regions 132 and 133, a phase of 2π can be emitted from the center of second green pixel-corresponding region 134, and a phase of 1.1π to 1.5π can be emitted from the junction of first green pixel-corresponding region 131 and second green pixel-corresponding region 134. Meanwhile, first green light phase distribution PPG1 does not mean that the phase delay of light passing through the center of first green pixel-corresponding region 131 is the largest, but rather, if the phase of light passing through other positions is determined to be 2π and the phase delay is even larger and has a phase value greater than 2π, it is also a distribution of the remaining value after removing about 2nπ, i.e., a wrapped phase. For example, if the phase of light passing through the first green pixel corresponding region 131 is 2π, and the phase of light passing through the center of the blue pixel corresponding region 132 is 3π, then the phase in the blue pixel corresponding region 132 is also the π remaining after removing 2π (when n = 1) from 3π.

[0062] 7A and 7C, the blue light passing through the color separation lens array 130 may have a phase distribution in which the phase is greatest at the center of the blue pixel corresponding region 132 and decreases in a direction away from the center of the blue pixel corresponding region 132. Specifically, the phase of the blue light immediately after passing through the color separation lens array 130 is greatest at the center of the blue pixel corresponding region 132 and gradually decreases concentrically with increasing distance from the center of the blue pixel corresponding region 132, reaching minimums at the centers of the first and second green pixel corresponding regions 131 and 134 in the X and Y directions, and minimums at the center of the red pixel corresponding region 133 in the diagonal direction. If the phase of blue light at the center of the blue pixel corresponding region 132 is 2π, then the phase at the centers of the first and second green pixel corresponding regions 131, 134 may be, for example, 0.5π to 0.9π, and the phase at the center of the red pixel corresponding region 133 may be a value smaller than the phase at the centers of the first and second green pixel corresponding regions 131, 134, for example, 0.2π to 0.8π.

[0063] The phase distribution PPb of blue light is different from the first phase distribution PPG1 of green light described above. This is because, as described with reference to FIGS. 3A and 3B, the color separation lens array 130 is designed so that the focal length of blue light obtained by the color separation lens array 130 is the same as the focal length of green light. If the thickness of the spacer layer 120 is determined based on the focal length of green light, adjusting the focal length of blue light to be the same as the focal length of green light will cause the green and blue lights to be focused at the same distance, which may improve the autofocus performance when the blue pixel 112 is an autofocus pixel including two or more photosensitive cells. The corrected focal length of blue light is 90% to 110% or 95% to 105% of the focal length of green light.

[0064] Comparing the first phase distribution PPG1 of green light with the phase distribution PPb of blue light, the difference between the phase of green light passing through the center of the first green pixel-corresponding region 131 and the phase of green light passing through the center of the blue pixel-corresponding region 132 is smaller than the difference between the phase of blue light passing through the center of the blue pixel-corresponding region 132 and the phase of blue light passing through the center of the first green pixel-corresponding region 131, for example, by approximately 0.1π to 0.6π.

[0065] In other words, the first phase distribution PPG1 of green light and the phase distribution PPb of blue light produced by the color separation lens array 130 are different from each other, and the phase decrease rate of blue light in the X direction is greater than the phase decrease rate of green light in the X direction.

[0066] Furthermore, the difference between the phase of green light that passes through the center of the first green pixel corresponding region 131 and the phase of green light that passes through the center of the blue pixel corresponding region 132 is 60% to 90% of the difference between the phase of blue light that passes through the center of the blue pixel corresponding region 132 and the phase of blue light that passes through the center of the first green pixel corresponding region 131.

[0067] FIG. 7D exemplarily shows the traveling direction of green light incident on a first green light collecting region, and FIG. 7E exemplarily shows an array of first green light collecting regions.

[0068] 7D, the green light incident on the periphery of the first green pixel-corresponding region 131 is collected by the color separation lens array 130 onto the first green pixel 111, and green light from the blue and red pixel-corresponding regions 132 and 133 as well as the first green pixel-corresponding region 131 is also incident on the first green pixel 111. That is, the phase distribution of the green light described in FIGS. 7A and 7B collects the green light that has passed through the first green light collecting region GL1 connecting the centers of the two blue pixel-corresponding regions 132 adjacent to the first green pixel-corresponding region 131 and the two red pixel-corresponding regions 133 onto the first green pixel 111. Therefore, as shown in FIG. 7E, the color separation lens array 130 can operate as a first green light collecting region GL1 array that collects green light onto the first green pixel 111. The first green light collecting region GL1 has an area larger than that of the corresponding first green pixel 111, for example, 1.2 to 2 times larger.

[0069] FIG. 7F exemplarily shows the traveling direction of blue light incident on a blue light collecting region, and FIG. 7G exemplarily shows an array of blue light collecting regions.

[0070] As shown in FIG. 7F, blue light is focused onto the blue pixel 112 by the color separation lens array 130, and blue light from pixel corresponding regions 131, 132, 133, and 134 is incident on the blue pixel 112. The phase distribution of blue light described in FIGS. 7A and 7C focuses the blue light passing through a blue light focusing region BL formed by connecting the centers of four red pixel corresponding regions 133 adjacent to the blue pixel corresponding region 132 with their vertices abutting. Therefore, as shown in FIG. 7G, the color separation lens array 130 can operate as a blue light focusing region BL array that focuses blue light onto the blue pixel 112. The blue light focusing region BL has an area larger than that of the corresponding blue pixel 112, for example, 1.5 to 4 times larger. The blue light focusing region BL may partially overlap with the first and second green light focusing regions GL1 and GL2 and the red light focusing region RL.

[0071] Comparing the phase distribution of green light that has passed through the first green light collection region GL1 with the phase distribution of blue light that has passed through the blue light collection region BL, the phase difference between green light that has passed through the center of the first green light collection region GL1 and green light that has passed through a position spaced from the center of the first green light collection region GL1 by the pixel pitch of the sensor substrate, for example, the center of the blue pixel corresponding region 132, is smaller than the phase difference between blue light that has passed through the center of the blue light collection region BL and blue light that has passed through a position spaced from the center of the blue light collection region BL by the pixel pitch of the sensor substrate, for example, the center of the first green light corresponding region 131. Similarly, the phase difference between green light passing through the center of the first green light collection region GL1 and green light passing through a position spaced from the center of the first green light collection region GL1 by about 1 / 2 the pixel pitch of the sensor substrate 110 (i.e., half the pixel pitch), for example, the center of the tangent between the first green pixel corresponding region 131 and the blue pixel corresponding region 132, is smaller than the phase difference between blue light passing through the center of the blue light collection region BL and blue light passing through a position spaced from the center of the blue light collection region BL by about 1 / 2 the pixel pitch of the sensor substrate 110, for example, the center of the tangent between the first green pixel corresponding region 131 and the blue pixel corresponding region 132.

[0072] Figure 8A shows the phase distribution of red light and green light that has passed through the color separation lens array 130 along line II-II' in Figure 6B, Figure 8B shows the phase of red light that has passed through the color separation lens array 130 at the center of pixel corresponding areas 131, 132, 133, and 134, and Figure 8C shows the phase of green light that has passed through the color separation lens array 130 at the center of pixel corresponding areas 131, 132, 133, and 134.

[0073] 8A and 8B, the red light passing through the color separation lens array 130 may have a phase distribution in which the phase is greatest at the center of the red pixel corresponding region 133 and decreases in a direction away from the center of the red pixel corresponding region 133. Specifically, the phase of the red light immediately after passing through the color separation lens array 130 is greatest at the center of the red pixel corresponding region 133 and gradually decreases concentrically with increasing distance from the center of the red pixel corresponding region 133, reaching minimums at the centers of the first and second green pixel corresponding regions 131 and 134 in the X and Y directions, and minimums at the center of the blue pixel corresponding region 132 in the diagonal direction. If the phase of red light at the center of the red pixel corresponding region 133 is 2π, then the phase at the centers of the first and second green pixel corresponding regions 131, 134 may be, for example, 1.1π to 1.5π, and the phase at the center of the blue pixel corresponding region 132 may be a value smaller than the phase at the centers of the first and second green pixel corresponding regions 131, 134, for example, 1.3π to 0.9π.

[0074] The phase distribution PPR of red light is different from the first phase distribution PPG1 of green light described above. This is because, as explained with reference to FIGS. 3A and 3B, the color separation lens array 130 is designed so that the focal length of red light through the color separation lens array 130 is the same as the focal length of green light. If the thickness of the spacer layer 120 is determined based on the focal length of green light, adjusting the focal length of red light to be the same as the focal length of green light will cause the green and red lights to be focused at the same distance, which can improve the autofocus performance when the red pixel is an autofocus pixel including two or more photosensitive cells. The corrected focal length of red light is 90% to 110% or 95% to 105% of the focal length of green light.

[0075] 8A and 8C, green light passing through the color separation lens array 130 may have a phase distribution that is greatest at the center of the second green pixel-corresponding region 134 and decreases in a direction away from the center of the second green pixel-corresponding region 134. Comparing the first phase distribution PPG1 of green light in FIG. 7A with the second phase distribution PPG2 of green light in FIG. 8A, the second phase distribution PPG2 of green light is identical to the first phase distribution PPG1 of green light translated by about one pixel pitch in the X and Y directions. That is, the first phase distribution PPG1 of green light has the greatest phase from the center of the first green pixel-corresponding region 131, while the second phase distribution PPG2 of green light has the greatest phase at the center of the second green pixel-corresponding region 131, which is about one pixel pitch away in the X and Y directions from the center of the first green pixel-corresponding region 131. The phase distributions in FIGS. 7B and 8C, which show the phases at the centers of the pixel-corresponding regions 131, 132, 133, and 134, are identical. Furthermore, if the phase distribution of green light is explained based on the second green pixel corresponding region 134, if the phase of the light emitted from the center of the second green pixel corresponding region 131 of green light is determined to be 2π as the reference, light with a phase of 0.9π to 1.1π can be emitted at the centers of the blue and red pixel corresponding regions 132 and 133, a phase of 2π can be emitted at the center of the first green pixel corresponding region 131, and a phase of 1.1π to 1.5π can be emitted at the intersection between the first green pixel corresponding region 131 and the second green pixel corresponding region 134.

[0076] Comparing the phase distribution PPR of red light with the second phase distribution PPG2 of green light, the difference between the phase of green light passing through the center of the second green pixel corresponding region 134 and the phase of green light passing through the center of the red pixel corresponding region 133 is larger than the difference between the phase of red light passing through the center of the red pixel corresponding region 133 and the phase of red light passing through the center of the second green pixel corresponding region 134, and can be, for example, larger by about 0.1π to 0.5π.

[0077] In other words, the second phase distribution PPG2 of green light and the phase distribution PPR of red light produced by the color separation lens array 130 are different from each other, and the phase decrease rate of green light in the X direction is greater than the phase decrease rate of red light in the X direction.

[0078] Furthermore, the difference between the phase of green light that has passed through the center of the second green pixel-corresponding region 134 and the phase of green light that has passed through the center of the red pixel-corresponding region 133 is 110% to 150% of the difference between the phase of red light that has passed through the center of the red pixel-corresponding region 133 and the phase of red light that has passed through the center of the second green pixel-corresponding region 134.

[0079] FIG. 8D exemplarily shows the traveling direction of red light incident on a red light collecting region, and FIG. 8E exemplarily shows an array of red light collecting regions.

[0080] As shown in FIG. 8D, the red light is focused onto the red pixel 113 by the color separation lens array 130, and the red light from the pixel corresponding regions 131, 132, 133, and 134 is incident on the red pixel 113. The phase distribution of the red light described in FIGS. 8A and 8B focuses the red light passing through a red light focusing region RL formed by connecting the centers of four blue pixel corresponding regions 132 adjacent to the red pixel corresponding region 133 with their vertices abutting. Therefore, as shown in FIG. 8E, the color separation lens array 130 can operate as a red light focusing region RL array that focuses red light onto the red pixel. The red light focusing region RL has an area larger than that of the corresponding red pixel 113, for example, 1.5 to 4 times larger. The red light focusing region RL may partially overlap with the first and second green light focusing regions GL1 and GL2 and the blue light focusing region BL.

[0081] FIG. 8F exemplarily shows the traveling direction of green light incident on the second green light collecting region, and FIG. 8G exemplarily shows an array of second green light collecting regions.

[0082] 8F and 8G, the green light incident on the periphery of the second green pixel-corresponding region 134 travels in the same manner as described for the green light incident on the periphery of the first green pixel-corresponding region 131, and is collected on the second green pixel 114 as shown in Fig. 8F. Therefore, as shown in Fig. 8G, the color separation lens array 130 can operate as an array of second green light collecting regions GL2 that collect green light on the second green pixel 114. The second green light collecting region GL2 has an area larger than that of the corresponding second green pixel 114, for example, 1.2 to 2 times larger.

[0083] Comparing the phase distribution of green light that has passed through the second green light collection region GL2 with the phase distribution of red light that has passed through the red light collection region RL, the phase difference between green light that has passed through the center of the second green light collection region GL2 and green light that has passed through a position spaced from the center of the second green light collection region GL2 by the pixel pitch of the sensor substrate 110, for example, the center of the red pixel corresponding region 133, is greater than the phase difference between red light that has passed through the center of the red light collection region RL and red light that has passed through a position spaced from the center of the red light collection region RL by the pixel pitch of the sensor substrate 110, for example, the second green light corresponding region 134. Similarly, the phase difference between green light passing through the center of the second green light collection region GL2 and green light passing through a position spaced from the center of the second green light collection region GL2 by about 1 / 2 the pixel pitch of the sensor substrate (i.e., half the pixel pitch), for example, the center of the tangent between the second green pixel corresponding region 131 and the red pixel corresponding region 133, is larger than the phase difference between red light passing through the center of the red light collection region RL and red light passing through a position spaced from the center of the red light collection region RL by about 1 / 2 the pixel pitch of the sensor substrate, for example, the center of the tangent between the second green pixel corresponding region 134 and the red pixel corresponding region 133.

[0084] 9A to 9C are diagrams for explaining the relationship between the focal length of the light-collecting area and the autofocus function.

[0085] As described above, a signal required for focus adjustment can be obtained using a pixel including two or more photosensitive cells sharing a light-collecting region. Specifically, of two photosensitive cells included in one pixel and sharing a light-collecting region, the image sensor 1000 can provide information for focusing by analyzing a difference between a signal sensed by a photosensitive cell located on one side (e.g., the first photosensitive cells 111a, 112a, 113a, and 114a) and a signal sensed by a photosensitive cell located on the other side (e.g., the second photosensitive cells 111b, 112b, 113b, and 114b). In this case, only when the focal lengths of the light-collecting regions GL1, GL2, BL, and RL are similar to the distance between the color separation lens array 130 and the sensor substrate 110, i.e., the thickness of the spacer layer 120, can the signals from the first photosensitive cells 111a, 112a, 113a, and 114a and the second photosensitive cells 111b, 112b, 113b, and 114b be clearly distinguished from each other, thereby improving the autofocus performance.

[0086] 9A shows an example in which the focal length f of the blue light collecting region BL is equal to the thickness 120h of the spacer layer 120. Referring to FIG. 9A, light with a wavelength of 450 nm incident in direction A toward the blue light collecting region BL may be incident on the first photosensitive cell 112a of the second pixel 112, and light incident in direction B may be incident on the second photosensitive cell 112b. That is, the signal sensed by the first photosensitive cell 112a of the second pixel 112 indicates the amount of light incident in direction A, and the signal sensed by the second photosensitive cell 112b of the second pixel 112 indicates the amount of light incident in direction B. In this case, the difference between the signals sensed by the first and second photosensitive cells 112a and 112b may be clearly distinguished depending on the traveling direction of the incident light.

[0087] 9B shows an example in which the focal length fa of the blue light collecting region BL is longer than the thickness 120h of the spacer layer 120. This phenomenon occurs because, as described with reference to FIGS. 3A and 3B, the thickness 120h of the spacer layer 120 is determined based on the focal length of green light, and the focal length of blue light is longer than that of green light when the phase distribution of the blue light collecting region BL is designed to be the same as that of the green light collecting regions GL1 and GL2. Referring to FIG. 9B, light with a wavelength of 450 nm incident in direction A toward the blue light collecting region BL is incident not only on the first photosensitive cell 112a of the second pixel 112 but also partially on the second photosensitive cell 112b surrounding the first photosensitive cell 112a, and light incident in direction B is incident not only on the second photosensitive cell 112b but also on the surrounding first photosensitive cell 112a. If the focal length of the blue light collecting region BL is greater than the thickness of the spacer layer 120, the difference in the signals from the photosensitive cells depending on the direction of the incident light becomes unclear, resulting in a decrease in focusing ability.

[0088] 9C shows an example in which the focal length fb of the blue light collecting region BL is shorter than the thickness 120h of the spacer layer 120. This phenomenon occurs because, as described with reference to FIGS. 3A and 3B, the thickness 120h of the spacer layer 120 is determined based on the focal length of green light, and the focal length of red light is shorter than that of green light when the phase distribution of the red light collecting region RL is designed to be the same as that of the green light collecting regions GL1 and GL2. Referring to FIG. 9C, light with a wavelength of 450 nm incident in direction A toward the blue light collecting region BL is incident not only on the first photosensitive cell 112a of the second pixel 112 but also partially on the second photosensitive cell 111b surrounding the first photosensitive cell 112a, and light incident in direction B is incident not only on the second photosensitive cell 112b but also on the surrounding first photosensitive cell 111a. As described above, not only when the focal length of the blue light collecting region BL is larger than the thickness of the spacer layer 120, but also when it is smaller than the thickness of the spacer layer 120, the difference in the signals from the individual photosensitive cells depending on the direction of incident light becomes unclear, resulting in a deterioration in focusing ability. That is, the sensing signals from the first photosensitive cells 111a, 112a, 113a, and 114a and the second photosensitive cells 111b, 112b, 113b, and 114b are not clearly distinguishable depending on the direction of incident light.

[0089] The image sensor 1000 including the pixel array 1100 described above has almost no light loss due to color filters, e.g., organic color filters, and can therefore provide a sufficient amount of light to pixels even when the pixel size is small. Therefore, it is possible to fabricate ultra-high-resolution, micro-high-sensitivity image sensors having hundreds of millions of pixels. Such ultra-high-resolution, micro-high-sensitivity image sensors can be used in a variety of high-performance optical or electronic devices. Examples of such electronic devices include, but are not limited to, smartphones, mobile phones, PDAs (personal digital assistants), laptops, PCs, various portable devices, home appliances, security cameras, medical cameras, automobiles, Internet of Things (IoT) devices, and other mobile or non-mobile computing devices.

[0090] In addition to the image sensor 1000, the electronic device may further include a processor, for example, an application processor (AP), that controls the image sensor. The processor may run an operating system or application program to control multiple hardware or software components and perform various data processing and calculations. The processor may further include a graphic processing unit (GPU) and / or an image signal processor. When the processor includes an image signal processor, the image (or video) acquired by the image sensor may be stored and / or output using the processor.

[0091] 10 is a block diagram illustrating an example of an electronic device ED01 including an image sensor 1000. Referring to FIG. 10, in the network environment ED00, the electronic device ED01 can communicate with another electronic device ED02 through a first network ED98 (e.g., a short-range wireless communication network) or with another electronic device ED04 and / or a server ED08 through a second network ED99 (e.g., a long-range wireless communication network). The electronic device ED01 can communicate with the electronic device ED04 through the server ED08. The electronic device ED01 includes a processor ED20, a memory ED30, an input device ED50, an audio output device ED55, a display device ED60, an audio module ED70, a sensor module ED76, an interface ED77, a haptic module ED79, a camera module ED80, a power management module ED88, a battery ED89, a communication module ED90, a subscriber identity module ED96, and / or an antenna module ED97. The electronic device ED01 may omit some of the components (such as the display device ED60) or add other components. Some of the components may be implemented as a single integrated circuit. For example, the sensor module ED76 (such as a fingerprint sensor, an iris sensor, or an illuminance sensor) may be embedded in the display device ED60 (such as a display).

[0092] The processor ED20 can execute software (e.g., program ED40) to control one or more different components (e.g., hardware and software components) of the electronic device ED01 coupled to the processor ED20 and perform various data processing or computations. As part of the data processing or computations, the processor ED20 can load instructions and / or data received from other components (e.g., sensor module ED76, communication module ED90) into volatile memory ED32, process the instructions and / or data stored in volatile memory ED32, and store the resulting data in non-volatile memory ED34. The processor ED20 includes a main processor ED21 (e.g., central processing unit, application processor) and an auxiliary processor ED23 (e.g., graphics processing unit, image signal processor, sensor hub processor, communication processor), which can operate independently or in conjunction with the main processor ED21. The auxiliary processor ED23 can use less power than the main processor ED21 and can perform specialized functions.

[0093] The auxiliary processor ED23 can control functions and / or states of some of the components of the electronic device ED01 (such as the display device ED60, the sensor module ED76, and the communication module ED90) in place of the main processor ED21 while the main processor ED21 is in an inactive state (sleep state), or together with the main processor ED21 while the main processor ED21 is in an active state (application execution state). The auxiliary processor ED23 (such as the image signal processor or the communication processor) may also be embodied as part of other functionally related components (such as the camera module ED80 and the communication module ED90).

[0094] The memory ED30 can store various data required by the components of the electronic device ED01 (such as the processor ED20 and the sensor module ED76). The data includes, for example, input and / or output data for software (such as the program ED40) and its associated instructions. The memory ED30 includes a volatile memory ED32 and / or a non-volatile memory ED34.

[0095] The program ED40 is stored as software in the memory ED30 and includes an operating system ED42, a middleware ED44 and / or an application ED46.

[0096] The input device ED50 can receive instructions and / or data from outside (such as a user) the electronic device ED01 for use by components (such as the processor ED20) of the electronic device ED01. The input device ED50 includes a microphone, a mouse, a keyboard, and / or a digital pen (such as a stylus pen).

[0097] The audio output device ED55 can output an audio signal to the outside of the electronic device ED01. The audio output device ED55 includes a speaker and / or a receiver. The speaker can be used for general purposes such as multimedia playback or recording and playback, and the receiver can be used to receive incoming calls. The receiver can be integrated into the speaker or implemented as a separate, independent device.

[0098] The display device ED60 can visually provide information outside the electronic device ED01. The display device ED60 includes a display, a holographic device, or a projector and control circuitry for controlling the device. The display device ED60 includes touch circuitry configured to sense a touch and / or sensor circuitry (such as a pressure sensor) configured to measure the strength of a force generated by the touch.

[0099] The audio module ED70 can convert sound into an electrical signal or vice versa, and can acquire sound through the input device ED50 or output sound through the audio output device ED55 and / or speakers and / or headphones of other electronic devices (such as the electronic device ED02) directly or wirelessly connected to the electronic device ED01.

[0100] The sensor module ED76 can sense the operating state (power, temperature, etc.) of the electronic device ED01 or the external environmental state (user state, etc.) and generate an electrical signal and / or a data value corresponding to the sensed state. The sensor module ED76 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 illuminance sensor.

[0101] The interface ED77 may support one or more specified protocols used for connecting the electronic device ED01 directly or wirelessly with other electronic devices (such as the electronic device ED02), including a High Definition Multimedia Interface (HDMI), a Universal Serial Bus (USB), an SD card interface, and / or an audio interface.

[0102] The connection terminal ED78 includes a connector that allows the electronic device ED01 to be physically connected to another electronic device (such as the electronic device ED02). The connection terminal ED78 includes an HDMI (registered trademark) connector, a USB connector, an SD card connector, and / or an audio connector (such as a headphone connector).

[0103] The haptic module ED79 can convert electrical signals into mechanical stimuli (such as vibrations or movements) or electrical stimuli that can be perceived by the user through touch or kinesthetic sensations. The haptic module ED79 includes motors, piezoelectric elements, and / or electrical stimulators.

[0104] Camera module ED80 can capture still and video images. Camera module ED80 includes a lens assembly including one or more lenses, image sensor 1000 of FIG. 1, an image signal processor, and / or a flash. The lens assembly included in camera module ED80 can collect light emitted from a subject from which an image is to be captured.

[0105] The power management module ED88 can manage the power supplied to the electronic device ED01. The power management module ED88 can be embodied as part of a PMIC (Power Management Integrated Circuit).

[0106] The battery ED89 can provide power to the components of the electronic device ED01. The battery ED89 includes a non-rechargeable primary battery, a rechargeable secondary battery, and / or a fuel cell.

[0107] The communication module ED90 can support the establishment of a direct (wired) communication channel and / or a wireless communication channel between the electronic device ED01 and other electronic devices (such as the electronic device ED02, the electronic device ED04, and the server ED08) and the execution of communication via the established communication channel. The communication module ED90 includes one or more communication processors that operate independently of the processor ED20 (such as an application processor) and support the direct communication and / or the wireless communication. The communication module ED90 includes a wireless communication module ED92 (such as a cellular communication module, a short-range wireless communication module, or a GNSS (Global Navigation Satellite System) communication module) and / or a wired communication module ED94 (such as a LAN (Local Area Network) communication module, or a power line communication module). Among these communication modules, the communication module can communicate with other electronic devices through a first network ED98 (a short-range communication network such as Bluetooth, WiFi Direct, or IrDA (Infrared Data Association)) or a second network ED99 (a long-range communication network such as a cellular network, the Internet, or a computer network (LAN, WAN, etc.)). These types of communication modules can be integrated into one component (such as a single chip) or embodied as multiple separate components (multiple chips). The wireless communication module ED92 can identify and authenticate the electronic device ED01 in a communication network such as the first network ED98 and / or the second network ED99 using subscriber information (such as an International Mobile Subscriber Identity (IMSI)) stored in the subscriber identity module ED96.

[0108] The antenna module ED97 can transmit signals and / or power to or receive signals from the outside (such as other electronic devices). The antenna includes a radiator made of a conductive pattern formed on a substrate (such as a PCB). The antenna module ED97 includes one or more antennas. When multiple antennas are included, the communication module ED90 can select an antenna from the multiple antennas that is suitable for a communication method used in a communication network such as the first network ED98 and / or the second network ED99. Signals and / or power are transmitted or received between the communication module ED90 and other electronic devices through the selected antenna. In addition to the antenna, other components (such as an RFIC) may be included as part of the antenna module ED97.

[0109] Some of the components are connected to each other through a communication method between peripheral devices (bus, GPIO (General Purpose Input and Output), SPI (Serial Peripheral Interface), MIPI (Mobile Industry Processor Interface), etc.) and can exchange signals (commands, data, etc.).

[0110] Commands or data may be transmitted or received between the electronic device ED01 and an external electronic device ED04 via a server ED08 connected to a second network ED99. The other electronic devices ED02 and ED04 may be the same or different types of devices as the electronic device ED01. All or part of the operations performed by the electronic device ED01 may be performed by one or more of the other electronic devices ED02, ED04, and ED08. For example, when the electronic device ED01 needs to perform a certain function or service, instead of performing the function or service itself, it may request one or more other electronic devices to perform the function or service in whole or in part. The one or more other electronic devices that receive the request may perform the additional function or service related to the request and transmit the results of the execution to the electronic device ED01. For this purpose, cloud computing, distributed computing, and / or client-server computing technologies may be used.

[0111] FIG. 11 is a block diagram illustrating the camera module ED80 of FIG. 10. Referring to FIG. 11, the camera module ED80 includes a lens assembly 1110, a flash 1120, an image sensor 1000 (e.g., image sensor 1000 of FIG. 1), an image stabilizer 1140, a memory 1150 (e.g., a buffer memory), and / or an image signal processor 1160. The lens assembly 1110 can collect light emitted from a subject to be imaged. The camera module ED80 may include multiple lens assemblies 1110. In such cases, the camera module ED80 can function as a dual camera, a 360° camera, or a spherical camera. Some of the multiple lens assemblies 1110 may have the same lens attributes (e.g., angle of view, focal length, autofocus, F-number, optical zoom, etc.) or different lens attributes. The lens assembly 1110 may include a wide-angle lens or a telephoto lens.

[0112] The flash 1120 can emit light used to enhance light emitted or reflected from an object. The flash 1120 can include one or more light-emitting diodes (e.g., RGB (Red-Green-Blue) LEDs), white LEDs, infrared LEDs, ultraviolet LEDs, etc.) and / or xenon lamps. The image sensor 1000 can also be the image sensor described in FIG. 1 and can capture an image corresponding to the object by converting light emitted or reflected from the object and transmitted through the lens assembly 1110 into an electrical signal. The image sensor 1000 can include one or more sensors selected from image sensors with different attributes, such as an RGB sensor, a BW (Black and White) sensor, an IR sensor, or a UV sensor. Each sensor included in the image sensor 1000 can be embodied as a CCD (Charged Coupled Device) sensor and / or a CMOS (Complementary Metal Oxide Semiconductor) sensor.

[0113] The image stabilizer 1140 may respond to movement of the camera module ED80 or the electronic device 1101 including it by moving one or more lenses included in the lens assembly 1110 or the image sensor 1000 in a specific direction or by controlling the operating characteristics of the image sensor 1000 (such as adjusting the read-out timing) to compensate for negative effects of the movement. The image stabilizer 1140 may sense the movement of the camera module ED80 or the electronic device ED01 using a gyro sensor (not shown) or an acceleration sensor (not shown) disposed inside or outside the camera module ED80. The image stabilizer 1140 may also be embodied optically.

[0114] The memory 1150 can store part or all of the data of an image acquired through the image sensor 1000 for subsequent image processing. 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 1150, and after displaying only the low-resolution image, the original data of the selected (e.g., user-selected) image is transmitted to the image signal processor 1160. The memory 1150 can be integrated into the memory ED30 of the electronic device ED01 or can be configured as a separate memory that operates independently.

[0115] The image signal processor 1160 may perform image processing on images acquired through the image sensor 1000 or image data stored in the memory 1150. Image processing may include depth map generation, 3D modeling, panorama generation, feature point extraction, image synthesis, and / or image compensation (noise reduction, resolution adjustment, brightness adjustment, blurring, sharpening, softening, etc.). The image signal processor 1160 may perform control (such as exposure time control or readout timing control) on components included in the camera module ED80 (such as the image sensor 1000). Images processed by the image signal processor 1160 may be stored back in the memory 1150 for further processing or provided to external components of the camera module ED80 (such as the memory ED30, display device ED60, electronic device ED02, electronic device ED04, or server ED08). The image signal processor 1160 may be integrated into the processor ED20 or may be configured as a separate processor that operates independently of the processor ED20. If the image signal processor 1160 is configured as a separate processor from the processor ED20, the image processed by the image signal processor 1160 may be displayed on the display device ED60 after undergoing additional image processing by the processor ED20.

[0116] The electronic device ED01 includes multiple camera modules ED80 with different attributes or functions. In such a case, one of the multiple camera modules ED80 is a wide-angle camera and another is a telephoto camera. Similarly, one of the multiple camera modules ED80 is a front camera and another is a rear camera.

[0117] The image sensor 1000 according to the embodiment may be applied to a mobile phone or smartphone 1200 shown in FIG. 12, a tablet or smart tablet 1300 shown in FIG. 13, a digital camera or camcorder 1400 shown in FIG. 14, a laptop computer 1500 shown in FIG. 15, or a television or smart TV 1600 shown in FIG. 16. For example, the smartphone 1200 or the smart tablet 1300 may include multiple high-resolution cameras, each equipped with a high-resolution image sensor. The high-resolution cameras may be used to extract depth information of an object in an image, adjust out-of-focus of the image, or automatically identify an object in the image.

[0118] The image sensor 1000 may also be applied to the smart refrigerator 1700 shown in FIG. 17, the security camera 1800 shown in FIG. 18, the robot 1900 shown in FIG. 19, the medical camera 2000 shown in FIG. 20, and the like. For example, the smart refrigerator 1700 automatically recognizes food in the refrigerator using an image sensor and notifies a user via a smartphone of the presence or absence of a specific food item, the type of food that has been stored or removed, and the like. The security camera 1800 provides ultra-high-resolution images and uses high sensitivity to enable recognition of objects or people in images even in dark environments. The robot 1900 can be deployed in disaster or industrial sites where people cannot directly approach and provide high-resolution images. The medical camera 2000 provides high-resolution images for diagnosis or surgery and can dynamically adjust the field of view.

[0119] 21, the image sensor 1000 may be applied to a vehicle 2100. The vehicle 2100 includes a plurality of vehicle cameras 2110, 2120, 2130, and 2140 arranged at various positions, and each of the vehicle cameras 2110, 2120, 2130, and 2140 includes an image sensor according to the embodiment. The vehicle 2100 can provide a driver with various information related to the inside or surroundings of the vehicle 2100 using the plurality of vehicle cameras 2110, 2120, 2130, and 2140, and can automatically recognize objects or people in the image to provide information necessary for autonomous driving.

[0120] Although the image sensor with the color separation lens array and the electronic device including the same have been described based on the embodiments shown in the drawings, these are merely examples, and a person skilled in the art would understand that various modifications and equivalent embodiments are possible. Therefore, the disclosed embodiments should be considered from an illustrative perspective, not a limiting perspective. The scope of the claims is set forth in the appended claims, not the foregoing description, and all differences within the scope of the claims should be construed as being within the scope of the claims. [Explanation of symbols]

[0121] 1000 image sensors 1010 Timing Controller 1020 Row Decoder 1030 Output circuit 1100 pixel array 110 Sensor board 111 1st green pixel 112 blue pixels 113 red pixels 114 Second green pixel 120 spacer layer 130 Color Separation Lens Array

Claims

1. a sensor substrate including first pixels for sensing light of a first wavelength and second pixels for sensing light of a second wavelength shorter than the first wavelength; a color separation lens array that focuses light of a first wavelength onto the first pixel and light of a second wavelength onto the second pixel, the color separation lens array including nanoposts having a cross-sectional diameter smaller than the first wavelength and the second wavelength, and a dielectric material that is provided around the nanoposts and has a refractive index lower than that of the nanoposts; The color separation lens array comprises: a first pixel corresponding region arranged at a position corresponding to the first pixel; a second pixel corresponding region arranged at a position corresponding to the second pixel, a phase difference between light of a first wavelength that has passed through a center of the first pixel corresponding region and light of the first wavelength that has passed through a center of the second pixel corresponding region is smaller than a phase difference between light of a second wavelength that has passed through a center of the first pixel corresponding region and light of the second wavelength that has passed through a center of the second pixel corresponding region; The nanoposts are light of a first wavelength that has passed through the first pixel corresponding region has a phase distribution that decreases in a direction away from the center of the first pixel corresponding region, The light of the second wavelength that has passed through the second pixel corresponding region has a phase distribution that decreases in a direction away from the center of the second pixel corresponding region. are arranged in the first pixel corresponding region and the second pixel corresponding region according to different rules, The focal length of the light of the second wavelength through the color separation lens array is 90% to 110% of the focal length of the light of the first wavelength through the color separation lens array.

2. An image sensor as described in claim 1, wherein the phase difference between light of a first wavelength that has passed through the center of the first pixel corresponding area and light of a first wavelength that has passed through the center of the first pixel corresponding area is 60% to 90% of the phase difference between light of a second wavelength that has passed through the center of the second pixel corresponding area and light of a second wavelength that has passed through the center of the second pixel corresponding area.

3. A phase difference between light of a first wavelength that has passed through a center of the first pixel corresponding region and light of a first wavelength that has passed through a center of the second pixel corresponding region is 0.9π to 1.1π; 3. The image sensor according to claim 1, wherein a phase difference between the light of the second wavelength that has passed through the center of the first pixel corresponding region and the light of the second wavelength that has passed through the center of the second pixel corresponding region is 1.1π to 1.5π.

4. 4. The image sensor according to claim 1, wherein the first pixel includes 2 to 16 photosensitive cells for sensing light of the first wavelength.

5. 5. The image sensor according to claim 1, wherein the second pixel includes 2 to 16 photosensitive cells for sensing light of the second wavelength.

6. 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 the signal generated by the image sensor; 6. An electronic device, wherein the image sensor is the image sensor according to claim 1.

Images