Image sensing device

Abstract

The present application relates to an image sensing device. The image sensing device includes a plurality of image pixels, a phase detection pixel, a first grid structure, and a second grid structure. The image pixel performs a conversion of incident light received through at least one first color filter so as to generate an image signal representing a target object to be captured. The phase detection pixel performs a conversion of incident light received through a second color filter so as to generate a phase signal for calculating a phase difference between images formed by the image signal. The first grid structure is disposed between any two of the first color filters and between any one of the first color filters and any one of the second color filters. The second grid structure is located adjacent to the first grid structure and is disposed between any one of the first color filters and any one of the second color filters.

Description

Technical Field

[0001] Technologies and implementations disclosed in this patent document generally relate to image sensing devices. Background Art

[0002] Image sensing devices are devices for capturing optical images by converting light into electrical signals using photosensitive semiconductor materials that react to light. With the development of the automotive, medical, computer, and communication industries, the demand for high-performance image sensing devices is increasing in various fields such as smart phones, digital cameras, game consoles, IOT (Internet of Things), robots, security cameras, and medical micro cameras.

[0003] Image sensing devices can be roughly divided into CCD (charge coupled device) image sensing devices and CMOS (complementary metal oxide semiconductor) image sensing devices. CCD image sensing devices provide better image quality, but they tend to consume more power and are larger than CMOS image sensing devices. Compared to CCD image sensing devices, CMOS image sensing devices are smaller in size and consume less power. In addition, CMOS sensors are manufactured using CMOS manufacturing technology, so that photosensitive elements and other signal processing circuits can be integrated into a single chip, which enables miniaturized image sensing devices to be produced at a lower cost. For these reasons, CMOS image sensing devices are being developed for many applications including mobile devices. Summary of the invention

[0004] Various embodiments of the disclosed technology relate to an image sensing device including phase detection pixels to improve phase detection characteristics.

[0005] According to an embodiment of the disclosed technology, an image sensing device may include: a plurality of image pixels, which are arranged to correspond to a first color filter and are configured to perform conversion of incident light from a target object to generate an image signal indicating the target object; a first color filter, which is placed above the image pixels to provide color filtering for the image pixels to capture color information of an image of the target object; phase detection pixels, which are placed between the image pixels and are configured to perform conversion of the incident light to generate a phase signal including information about a phase difference between images formed by the image signal; a second color filter, which is placed above the phase detection pixels, respectively, to guide the incident light to the phase detection pixels; a first grid structure, which is arranged between any two of the first color filters and between any one of the first color filters and any one of the second color filters; and a second grid structure, which is located adjacent to the first grid structure and is arranged between any one of the first color filters and any one of the second color filters.

[0006] According to another embodiment of the disclosed technology, an image sensing device may include an image pixel array of image pixels, a plurality of color filters, and a grid structure. The image pixels generate pixel signals in response to light. The plurality of color filters may be placed above the image pixel array and arranged in a first direction and a second direction perpendicular to the first direction, and may filter incident light to be detected by the image pixel array, and the grid structure may be disposed between any two color filters in the plurality of color filters. The grid structure may include a first grid structure and a second grid structure. The first grid structure may include a first material layer. The second grid structure may be arranged adjacent to the first grid structure, and may include a second material layer having properties different from those of the first material layer.

[0007] It is to be understood that both the foregoing general description and the following detailed description of the disclosed technology are exemplary and explanatory and are intended to provide further explanation of the disclosure as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The above and other features and advantageous aspects of the disclosed technology will become apparent with reference to the following detailed description when considered in conjunction with the accompanying drawings.

[0009] Figure 1 is a block diagram illustrating an example of an image sensing device based on some implementations of the disclosed technology.

[0010] Figure 2 This is an example of an embodiment based on the disclosed technology. Figure 1 Example plan views of portions of a pixel array are shown.

[0011] Figure 3 is an example of some implementations based on the disclosed technology. Figure 2 A cross-sectional view of an example of a pixel array taken along line XX′ is shown.

[0012] 4A to 4D is an example of some implementations based on the disclosed technology for forming Figure 3 A cross-sectional view of an example of a method of showing a first grid and a second grid.

[0013] Figure 5 is an example of some implementations based on the disclosed technology. Figure 2 A cross-sectional view of another example of a pixel array taken along line XX′ is shown. DETAILED DESCRIPTION

[0014] This patent document provides implementations and examples of image sensing devices, and the disclosed features can be implemented to achieve one or more advantages in more applications. Some implementations of the disclosed technology propose designs of image sensing devices that include phase detection pixels to improve phase detection characteristics. The disclosed technology provides various implementations of image sensing devices that improve the structural characteristics of the grid structure, thereby obtaining low-exposure pixel signals using only one exposure.

[0015] Reference will now be made in detail to certain embodiments, examples of which are shown in the accompanying drawings. As much as possible, the same reference numerals are used throughout the drawings to refer to the same or similar components. In the following description, detailed descriptions of related known configurations or functions incorporated herein will be omitted to avoid obscuring the technical subject.

[0016] Figure 1 is a block diagram illustrating an image sensing device according to an embodiment of the disclosed technology.

[0017] Reference Figure 1 , the image sensing device may include a pixel array 100 , a row driver 200 , a correlated double sampler (CDS) 300 , an analog-to-digital converter (ADC) 400 , an output buffer 500 , a column driver 600 , and a timing controller 700 . Figure 1 The components of the image sensing device shown are discussed by way of example only, and this patent document encompasses numerous other alterations, substitutions, variations, modifications, and modifications.

[0018] The pixel array 100 may include a plurality of unit pixels arranged in rows and columns. In one example, the plurality of unit pixels may be arranged in a two-dimensional pixel array including rows and columns. In another example, the plurality of unit pixels may be arranged in a three-dimensional pixel array. The plurality of unit pixels may convert an optical signal into an electrical signal based on a unit pixel or based on a pixel group, wherein the unit pixels in the pixel group share at least one internal circuit. The plurality of unit pixels may include a plurality of imaging pixels and a plurality of phase detection pixels. Each image pixel may generate an image signal serving as an electrical signal corresponding to a target object to be captured. Each phase detection pixel may generate a phase signal serving as an electrical signal for calculating a phase difference between images captured by the image pixel.

[0019] The pixel array 100 may receive driving signals including row selection signals, reset signals, and transfer signals from the row driver 200. Upon receiving the driving signals, corresponding unit pixels in the pixel array 100 may be activated to perform operations corresponding to the row selection signals, reset signals, and transfer signals.

[0020] The row driver 200 may activate the pixel array 100 to perform certain operations on the unit pixels in the corresponding row based on the command and control signals provided by the controller circuit such as the timing controller 700. In some implementations, the row driver 200 may select one or more unit pixels arranged in one or more rows of the pixel array 100. The row driver 200 may generate a row selection signal to select one or more rows among a plurality of rows. The row driver 200 may sequentially enable a reset signal for resetting the imaging pixel corresponding to at least one selected row and a transmission signal for the pixel corresponding to at least one selected row. Thus, a reference signal and an image signal, which are analog signals generated by each of the imaging pixels of the selected row, may be sequentially transmitted to the CDS 300. The reference signal may be an electrical signal provided to the CDS 300 when a sensing node (e.g., a floating diffusion node) of the imaging pixel is reset, and the image signal may be an electrical signal provided to the CDS 300 when a photocharge generated by the imaging pixel is accumulated at the sensing node. The reference signal indicating unique reset noise of each pixel and the image signal indicating the intensity of incident light may be collectively referred to as a pixel signal as needed.

[0021] CMOS image sensors can use correlated double sampling (CDS) to remove undesired offset values ​​of pixels, known as fixed pattern noise, by sampling the pixel signal twice to remove the difference between the two samples. In one example, correlated double sampling (CDS) can remove undesired offset values ​​of pixels by comparing pixel output voltages obtained before and after photocharges generated by incident light are accumulated in a sensing node, so that a pixel output voltage based only on incident light can be measured.

[0022] In some embodiments of the disclosed technology, the CDS 300 may sequentially sample and hold the voltage level of the image signal and the reference signal provided to each of the plurality of column lines from the pixel array 100. That is, the CDS 300 may sample and hold the voltage level of the image signal and the reference signal corresponding to each column of the pixel array 100.

[0023] In some implementations, the CDS 300 may transmit the image signal and the reference signal of each column as a correlated double sampling signal to the ADC 400 based on a control signal from the timing controller 700 .

[0024] ADC 400 is used to convert the analog CDS signal into a digital signal. In some implementations, ADC 400 can be implemented as a ramp comparison ADC. The ramp comparison ADC may include: a comparator circuit for comparing the analog pixel signal with a reference signal such as a ramp signal that ramps up or ramps down; and a timer for performing counting until the voltage of the ramp signal matches the analog pixel signal. In some embodiments of the disclosed technology, ADC 400 may convert the correlated double sampling signal generated by CDS 300 for each column into a digital signal and output the digital signal.

[0025] The ADC 400 may include a plurality of column counters. Each column of the pixel array 100 is connected to a column counter, and image data may be generated by converting a correlated double sampling signal received from each column into a digital signal using the column counter. In another embodiment of the disclosed technology, the ADC 400 may include a global counter to convert a correlated double sampling signal corresponding to a column into a digital signal using a global code provided from the global counter.

[0026] The output buffer 500 may temporarily hold the column-based image data provided from the ADC 400 to output the image data. In one example, the image data provided from the ADC 400 to the output buffer 500 may be temporarily stored in the output buffer 500 based on a control signal of the timing controller 700. The output buffer 500 may provide an interface to compensate for an image processing rate difference or a transmission rate difference between the image sensing device and other devices.

[0027] The column driver 600 may select a column of the output buffer upon receiving a control signal from the timing controller 700, and sequentially output image data temporarily stored in the selected column of the output buffer 500. In some implementations, after receiving an address signal from the timing controller 700, the column driver 600 may generate a column selection signal based on the address signal and select a column of the output buffer 500, and output image data from the selected column of the output buffer 500 as an output signal.

[0028] The timing controller 700 may control operations of the row driver 200 , the ADC 400 , the output buffer 500 , and the column driver 600 .

[0029] The timing controller 700 may provide clock signals required for the operation of the corresponding components of the image sensing device, control signals for timing control, and address signals for selecting rows or columns to the row driver 200, the column driver 600, the ADC 400, and the output buffer 500. In an embodiment of the disclosed technology, the timing controller 700 may include a logic control circuit, a phase-locked loop (PLL) circuit, a timing control circuit, a communication interface circuit, etc.

[0030] Figure 2 This is an example of an embodiment based on the disclosed technology. Figure 1 An example plan view of some portions of pixel array 100 is shown.

[0031] Reference Figure 2 , the pixel array 100 may include a plurality of unit pixels arranged in row and column directions. The plurality of unit pixels may include a plurality of image pixels PX_R, PX_G, and PX_B and a plurality of phase detection pixels LPD and RPD. The plurality of image pixels PX_R, PX_G, and PX_B may generate image signals corresponding to a target object to be captured. The phase detection pixels LPD and RPD may generate a phase signal for calculating a phase difference between images obtained from the captured target object.

[0032] In order to enable the capture of color information in an image, a color filter layer with different color filters is provided to cover the photosensitive element below, and the spatial arrangement of the different color filters is designed to use different color filters in adjacent pixels to filter the incident light to capture the color information of the scene or object to be imaged. A suitable color filter arrangement is a Bayer color filter array of different color filters, which includes 50% of all color filters being green (G), 25% of all color filters being blue (B) and 25% of all color filters being red (R). One of the different implementations of the Bayer color filter array for placing adjacent color filters of the same color in rows or columns is a four-Bayer pixel structure, in which adjacent 2×2 pixels of a 4-pixel block are the same color as a basic building block while realizing the Bayer color arrangement by making 50% of all 4-pixel color filter blocks green (G), 25% of all 4-pixel color filter blocks blue (B) and 25% of all 4-pixel color filter blocks red (R).

[0033] Figure 2 The example in shows an example of a 4×4 4-pixel block pattern in which such a four-Bayer pixel structure includes a 4-pixel block of a blue filter, a 4-pixel block of a red filter, and two 4-pixel blocks of green filters. This design is a specific implementation of the Bayer pattern by including a structure in which unit pixels having filters of the same color are arranged adjacent to each other in an (N×N) array (where “N” is a natural number of 2 or greater) in each of the image pixels PX_R, PX_G, and PX_B. For example, as Figure 2As shown, each of the image pixels PX_R, PX_G, and PX_B has a quaternary structure in which four unit pixels having the same color are arranged in a (2×2) array. In some implementations, the image pixel PX_R may include a red sub-pixel block, each of which has a structure in which four red pixels (PX_R) having a red color filter are arranged in a (2×2) array, the image pixel PX_G may include a green sub-pixel block, each of which has a structure in which four green pixels (PX_G) having a green color filter are arranged in a (2×2) array, and the image pixel PX_B may include a blue sub-pixel block, each of which has a structure in which blue pixels (PX_B) having a green color filter are arranged in a (2×2) array. The red sub-pixel block (PX_R), the green sub-pixel block (PX_G), and the blue sub-pixel block (PX_B) may be arranged in a Bayer pattern.

[0034] Among the unit pixels, in addition to the image pixels, a plurality of phase detection pixels are arranged in the horizontal direction and the vertical direction for detecting both the horizontal phase difference and the vertical phase difference. The plurality of phase detection pixels LPD and RPD may include two phase detection pixels adjacent to each other in the horizontal or vertical direction, or may include four phase detection pixels adjacent to each other in the horizontal and vertical directions. Figure 2 An example is shown in which two phase detection pixels LPD and RPD are included, but other implementations are possible. Phase detection pixels LPD and RPD adjacent to each other may include filters of the same color. In one example, Figure 2 The phase detection pixels LPD and RPD are shown to include a green color filter. In other implementations, the phase detection pixels LPD and RPD may include color filters other than green color filters.

[0035] In the pixel array 100, the grid structure 120 may be disposed between color filters of the unit pixel so that crosstalk between adjacent color filters among the color filters may be prevented by the grid structure 120. The grid structure 120 may be formed in different shapes based on the position of the grid structure 120.

[0036] In one example, the grid structure 120 may include a first grid 120M and a second grid 120A.

[0037] The first grid 120M may include a metal layer 120M. The first grid 120M may be disposed between any two adjacent color filters of the image pixels PX_R, PX_G, and PX_B and between any color filter of the image pixel PX_R, PX_G, or PX_B and a color filter of the phase detection pixel LPD or RPD.

[0038] The second grid 120A may include a low refractive index layer 120A such as an air layer. The second grid 120A may be disposed between any color filter of the image pixel PX_R, PX_G, or PX_B and any color filter of the phase detection pixel LPD or RPD. Thus, in a certain area between any color filter of the phase detection pixel LPD or RPD and any color filter of the image pixel PX_R, PX_G, or PX_B, the grid structure 120 may be formed as a double structure in which a metal layer 120M and an air layer 120A are stacked. In other areas except a certain area, the grid structure 120 may be formed as a single structure including a metal layer 120M. The first grid 120M and the second grid 120A may be located around the phase detection pixels LPD and RPD. In this case, the first grid 120M and the second grid 120A may be adjacent to each other so that the first grid 120M is located outside the second grid 120A. The second grid 120A may be formed in a ring shape surrounding the phase detection pixels LPD and RPD.

[0039] As described above, since the air layer 120A may be formed to overlap the metal layer 120M in a certain area between any color filter of the image pixel PX_R, PX_G, or PX_B and any color filter of the phase detection pixel LPD or RPD, the air layer 120A may more effectively block light that causes crosstalk in the phase detection pixels LPD and RPD by the chief ray angle (CRA). Thus, the phase detection characteristics may be increased.

[0040] Figure 3 is an example of some implementations based on the disclosed technology. Figure 2 A cross-sectional view of an example of the pixel array 100 is shown taken along line XX′.

[0041] Reference Figure 2 and Figure 3 , the pixel array 100 may include a substrate layer 110 , a grid structure 120 , a color filter layer 130 , and a lens layer 140 .

[0042] The substrate layer 110 may include a substrate 112, a plurality of photoelectric conversion elements 114, and a plurality of device isolation structures 116. The substrate layer 110 may include a first surface and a second surface facing the first surface or opposite to the first surface. In this case, the first surface may refer to a light incident surface on which external light is incident.

[0043] The substrate 112 may include a semiconductor substrate including a single crystal silicon material. The substrate 112 may include P-type impurities.

[0044] The photoelectric conversion elements 114 may be formed in the semiconductor substrate 112 so as to correspond to the unit pixels, respectively. The photoelectric conversion elements 114 may perform photoelectric conversion of incident light (eg, visible light) filtered by the color filter layer 130, and thus may generate photocharges. Each of the photoelectric conversion elements 114 may include N-type impurities.

[0045] Each device isolation structure 116 may be formed between the photoelectric conversion elements 114 of adjacent unit pixels within the substrate 112, thereby isolating the photoelectric conversion elements 114 from each other. The device isolation structure 116 may include a trench structure such as a back deep trench isolation (BDTI) structure or a front deep trench isolation (FDTI) structure. Alternatively, the device isolation structure 116 may include a junction isolation structure formed by injecting high-density impurities (e.g., P-type impurities) into the substrate 112.

[0046] The grid structure 120 may be disposed between any two color filters to prevent crosstalk between adjacent color filters. The grid structure 120 may be formed over the first surface of the substrate layer 110. The grid structure 120 may include a first grid 120M and a second grid 120A.

[0047] The first grid 120M may include a metal layer 122, a first cover layer 124, and a second cover layer 128. The second grid 120A may include an air layer 126 and a second cover layer 128.

[0048] The metal layer 122 may include tungsten (W). The metal layer 122 may be formed as a stacked structure of tungsten and a barrier metal layer (not shown).

[0049] The first capping layer 124 may include a nitride film and may be formed to extend under the air layer 126 and the color filter layer 130 while covering the metal layer 122. The first capping layer 124 may prevent expansion of the metal layer 122 during the thermal annealing process. In the first capping layer 124, a region formed under the color filter layer 130 may function as a portion of an anti-reflection layer.

[0050] In a certain area between any color filter of the phase detection pixel LPD or RPD and any color filter of the image pixel PX_R, PX_G, or PX_B, an air layer 126 may be formed on the inner side of the first grid 120M. The air layer 126 may be formed above the first cover layer 124. Figure 3 The air layer 126 is illustrated as having a top surface that is set higher than the top surface of the metal layer 122, but other implementations are possible. For example, the top surfaces of the air layer 126 and the metal layer 122 may be at the same height. In some implementations, the air layer 126 may have a top surface that is set lower than the top surface of the metal layer 122.

[0051] The second capping layer 128 may cover the air layer 126. The second capping layer 128 may include an oxide film. The oxide film may include, for example, a silicon oxide film (SiO 2 ) or an ultra low temperature oxide (ULTO) film such as an . The second covering layer 128 may be formed to overlap with the first covering layer 124 in a region where the first grid 120M and the color filter layer 130 are formed. In the second covering layer 128, a region formed below the color filter layer 130 may be used as a part of an anti-reflection layer. Thus, in the first covering layer 124 and the second covering layer 128, some regions disposed below the color filter layer 130 may be used as an anti-reflection layer that compensates for the difference in refractive index between the color filter layer 130 and the substrate 112, thereby enabling light that has penetrated the color filter layer 130 to be effectively incident on the substrate 112. Therefore, there is no need to provide a separate anti-reflection layer between the color filter layer 130 and the substrate 112.

[0052] The color filter layer 130 may include a color filter that filters visible light from the incident light received through the lens layer 140 and transmits the filtered light to the corresponding photoelectric conversion element 114. The color filter layer 130 may include a plurality of red filters (R), a plurality of green filters (G) and a plurality of blue filters (B). Each red filter (R) can transmit red visible light having a first wavelength band. Each green filter (G) can transmit green visible light having a second wavelength band shorter than the first wavelength band. Each blue filter (B) can transmit blue visible light having a third wavelength band shorter than the second wavelength band. The color filter layer 130 may be formed above the substrate layer 110 in an area defined by the first grid 120M and the second grid 120A.

[0053] The lens layer 140 may include an overcoat 142 and a plurality of microlenses 144. The overcoat 142 may be formed over the color filter layer 130. The overcoat 142 may be used as a planarization layer to compensate (or remove) the step difference caused by the color filter layer 130. The microlenses 144 may be formed over the overcoat 142. Each microlens 144 may be formed in a hemispherical shape and may be formed per unit pixel (PX). The microlenses 144 may converge incident light and may transmit the converged light to the corresponding color filters R, G, and B. The overcoat 142 and the microlenses 144 may be formed of the same material.

[0054] 4A to 4D is a cross-sectional view illustrating an example of a method for forming a grid structure based on some implementations of the disclosed technology. Figure 3 As discussed, the grid structure includes a first grid and a second grid.

[0055] Reference Figure 4A, a metal material may be formed over the substrate layer 110 including the photoelectric conversion element and the device isolation structure.

[0056] For example, after forming a metal material over the substrate layer 110, the metal material may be etched using a mask pattern (not shown) defining a grid structure region as an etching mask, resulting in forming the metal layer 122. In this case, the metal layer 122 may include tungsten (W).

[0057] Subsequently, the first capping layer 124 may be formed over the substrate layer 110 and the metal layer 122. In this case, the first capping layer 124 may include a nitride film.

[0058] Reference Figure 4B , a sacrificial film pattern 125 may be formed over the first capping layer 124 in a region serving as a formation region of the second grid 120A.

[0059] For example, after forming a sacrificial film (not shown) over the entire first capping layer 124, a mask pattern (not shown) defining a region of the second grid 120A may be formed over the sacrificial film. In this case, the sacrificial film may include a spin-on carbon (SOC) film containing carbon. Subsequently, the sacrificial film may be etched using the mask pattern as an etching mask, resulting in the formation of a sacrificial film pattern 125.

[0060] Reference Figure 4C , a second capping layer 128 may be formed over the first capping layer 124 and the sacrificial film pattern 125 .

[0061] In this case, the second capping layer 128 may include an ultra low temperature oxide (ULTO) film. In some implementations, the second capping layer 128 may be formed to a predetermined thickness through which molecules formed by combining the gas with the carbon of the sacrificial film pattern 125 can pass and be easily discharged to the outside.

[0062] Reference Figure 4D , can be Figure 4C The resulting structure is subjected to a plasma process so that the sacrificial film pattern 125 can be removed and an air layer 126 can be formed at a location where the sacrificial film pattern 125 is removed. In some implementations, a gas including at least one of oxygen, nitrogen, or hydrogen (e.g., O 2 、N 2 , H 2 ,CO,CO 2 or CH 4 ) to perform plasma processing.

[0063] Reference Figure 4C , if in Figure 4C The resulting structure is subjected to O 2In the plasma process, oxygen radicals (O*) may flow into the sacrificial film pattern 125 through the second capping layer 128, and the oxygen radicals (O*) included in the sacrificial film pattern 125 may be combined with carbon of the sacrificial film pattern 125, resulting in the formation of CO or CO 2 The CO or CO formed 2 The liquid may pass through the second cover layer 128 and be discharged to the outside.

[0064] As a result, the sacrificial film pattern 125 may be removed, and an air layer 126 may be formed at a position where the sacrificial film pattern 125 is removed.

[0065] The color filter layer 130 may be formed over the second cover layer 128 to fill the region defined by the first grid 120M and the second grid 120A, and the lens layer 140 may be formed over the color filter layer 130 .

[0066] Figure 5 is an example of some implementations based on the disclosed technology. Figure 2 The cross-sectional view of another example of the pixel array 100 is taken along line XX′.

[0067] Reference Figure 2 and Figure 5 , the second grid 120A may be formed as a hybrid structure indicating a stacked structure of a metal layer and an air layer. For example, the first grid 120M may include a metal layer 122a, a first cover layer 124, and a second cover layer 128. The second grid 120A may include a metal layer 122b, a first cover layer 124, an air layer 126', and a second cover layer 128.

[0068] In some implementations, metal layer 122 ′ disposed between color filters of image pixels PX_R, PX_G, and PX_B and color filters of phase detection pixels LPD and RPD may be formed to have a greater width so that metal layer 122 ′ may extend under air layer 126 ′, unlike metal layer 122 described above.

[0069] Although for ease of description Figure 5 The metal layer 122 ′ is shown to be divided into two metal layers 122 a and 122 b , but the scope or spirit of the disclosed technology is not limited thereto, and the two metal layers 122 a and 122 b may also be integrated into one structure as desired.

[0070] As is apparent from the above description, an image sensing device based on some implementations of the disclosed technology can improve the structural characteristics of a grid structure and thus can acquire a low-exposure pixel signal using only one exposure.

[0071] Although a number of exemplary embodiments have been described, it should be understood that modifications and other embodiments of the disclosed embodiments may be designed based on what is described and / or illustrated in this patent document.

[0072] CROSS-REFERENCE TO RELATED APPLICATIONS

[0073] This patent document claims priority to and the benefits of Korean Patent Application No. 10-2020-0180008, filed on December 21, 2020, the entire contents of which are incorporated herein by reference as part of the disclosure of this patent document.

Claims

1. An image sensing device, comprising: a plurality of image pixels corresponding to the first color filter and performing conversion of incident light from a target object to generate an image signal indicative of the target object; a first color filter disposed in the image pixel to provide color filtering for the image pixel to capture color information of the image of the target object; a phase detection pixel which is placed between the image pixels and performs conversion of incident light to generate a phase signal including information on a phase difference between images formed by the image signals; second color filters, the second color filters being respectively placed in the phase detection pixels to guide the incident light to the phase detection pixels; as well as A grid structure, the grid structure comprising: a first grid structure disposed in a first region between any two of the first color filters and in a second region between any one of the first color filters and any one of the second color filters; and a second grid structure positioned adjacent to the first grid structure in the second region between any one of the first color filters and any one of the second color filters, wherein the second grid structure surrounds the second color filter, wherein the first grid structure surrounds the second grid structure, and The grid structure is formed as a double structure in the second region, and is formed as a single structure including the first grid structure in the first region.

2. The image sensing device according to claim 1, wherein: The first grid structure and the second grid structure include different material layers from each other.

3. The image sensing device according to claim 1, wherein: The first grid structure includes a metal layer.

4. The image sensing device according to claim 3, wherein: The first grid structure further comprises: A covering layer is formed to cover the metal layer.

5. The image sensing device according to claim 4, wherein: The cover layer includes a stacked structure in which insulating layers having different characteristics are stacked.

6. The image sensing device according to claim 2, wherein: The second grid structure includes an air layer.

7. The image sensing device according to claim 6, wherein: The second grid structure further comprises: A cover layer is provided to cover the air layer.

8. The image sensing device according to claim 6, wherein: The second grid structure comprises: A hybrid structure in which a metal layer and the air layer are vertically stacked.

9. The image sensing device according to claim 8, wherein: The second grid structure further comprises: a first covering layer disposed between the metal layer and the air layer; and A second covering layer is provided to cover the air layer.

10. The image sensing device according to claim 9, wherein: The first cover layer and the second cover layer include insulating layers having different characteristics.

11. The image sensing device according to claim 1, wherein: The second grid structure has a ring shape surrounding the second color filter.

12. The image sensing device according to claim 1, wherein: The first color filters include two adjacent color filters having a common color.

13. An image sensing device, comprising: an image pixel array of image pixels, each image pixel responsive to light to produce a pixel signal; a plurality of color filters disposed in the image pixel array and arranged along a first direction and a second direction perpendicular to the first direction and filtering incident light to be detected by the image pixel array; as well as a grid structure disposed between any two color filters among the plurality of color filters, Wherein, the grid structure comprises: a first grid structure comprising a first material layer; and a second grid structure, the second grid structure being arranged adjacent to the first grid structure and comprising a second material layer, the second material layer having different properties than the first material layer, wherein the first grid structure surrounds the second grid structure, and The grid structure is formed as a double structure in which the first material layer and the second material layer are stacked in the first region, and is formed as a single structure including the first material layer in the second region except the first region.

14. The image sensing device according to claim 13, wherein: The first material layer includes a metal layer.

15. The image sensing device according to claim 13, wherein: The second material layer includes an air layer.

16. The image sensing device according to claim 13, wherein: The second grid structure comprises: A hybrid structure in which the first material layer and the second material layer are stacked.

17. The image sensing device according to claim 13, further comprising phase detection pixels between the image pixels to generate phase signals indicating phase differences between images formed by pixel signals from the image pixels, and in, The plurality of color filters include: a first color filter disposed above the image pixel to filter incident light to be detected by the image pixel to capture color information in the incident light; and A second color filter is disposed above the phase detection pixel and filters light to be detected by the phase detection pixel.

18. The image sensing device according to claim 17, wherein: The second grid structure has a ring shape surrounding the second color filter.

19. The image sensing device according to claim 17, wherein: The first color filters include two adjacent first color filters of the same color.

20. The image sensing device according to claim 17, wherein: The first color filter includes 2×2 blocks of first color filters, wherein each 2×2 block of first color filters includes first color filters having a common color.

Images