Image-sensing device

Abstract

To provide an image-sensing device capable of miniaturizing an optical loss, and improving a Gr / Gb.SOLUTION: The present invention provides an image-sensing device which contains a pixel array 1100 into which a plurality of unit pixels is arranged. Each unit pixel contains a plurality of sub-pixels 300, 400, and 500. In a boundary region of the sub-pixel 300, a first separation region 310 is formed, and a second separation region 320 is formed to a center part direction of the sub-pixel 300 in the first separation region 310. The second separation region 320 contains: a first inner separation region 321 that is projected and formed to the center part direction of the sub-pixel 300 in one region of the first separation region 310; and a second inner separation region 322 that is formed on the same straight line with the first inner separation region 321, and is projected and formed to the center part direction of the sub-pixel 300 in the other region of the first separation region 310. To a direction orthogonal to between the first inner separation region 321 and the second inner separation region 322, a third separation region 330 is formed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an image sensing device, and more particularly to an image sensing device capable of improving an output signal difference (Gr / Gb) between Gr pixels and Gb pixels.

Background Art

[0002] An image sensing device is a device that captures an optical image using the property of a light-sensitive semiconductor material that reacts to light. With the development of industries such as automobiles, medicine, computers, and communications, there is an increasing demand for high-performance image sensing devices in various fields such as smartphones, digital cameras, gaming devices, Internet of Things, robots, security cameras, and medical micro cameras.

[0003] Image sensing devices are broadly classified into CCD (Charge Coupled Device) image sensing devices and CMOS (Complementary Metal Oxide Semiconductor) image sensing devices.

[0004] In the case of a 2PD (Dual Photodiode) type image sensing device, light incident on a microlens is scattered by a deep trench isolation (DTI) and penetrates the wall surface of adjacent pixels, acting as crosstalk.

[0005] In the case of the red wavelength, due to the long wavelength absorption rate, the penetration amount with respect to adjacent pixels is even larger than that of the blue wavelength and the green wavelength. Therefore, depending on the 2PD direction of the red pixel, the signal of the Gr pixel or the Gb pixel may increase.

[0006] Depending on the 2PD direction of the red pixel, Gr / Gb has a value smaller than 1 or larger than 1, resulting in degradation.

Summary of the Invention

Problems to be Solved by the Invention

[0007] The technical problem to be solved by the present invention is to provide an image sensing device that can minimize light loss and improve Gr / Gb by forming a light scattering region.

Means for Solving the Problems

[0008] According to an embodiment, an image sensing device is provided. The image sensing device includes a pixel array in which a plurality of unit pixels are arranged. The unit pixel includes a plurality of sub-pixels. A first separation region is formed in a boundary region of the sub-pixels. A second separation region is formed in the first separation region in a direction toward the center of the sub-pixels. The second separation region includes a first inner separation region that protrudes in a direction toward the center of the sub-pixels in one region of the first separation region, and a second inner separation region that is formed on the same straight line as the first inner separation region and protrudes in a direction toward the center of the sub-pixels in another region of the first separation region. A third separation region may be formed in a direction orthogonal to a direction between the first inner separation region and the second inner separation region.

[0009] The sub-pixel may include the first separation region, the second separation region including the first inner separation region and the second inner separation region, an insulating layer formed on an upper portion of the first separation region and the second separation region, the third separation region formed under the insulating layer, a color filter formed on an upper portion of the insulating layer, and a microlens formed on an upper portion of the color filter.

[0010] The second inner separation region may be formed at a position spaced apart from the first inner separation region by a certain distance.

[0011] The third separation region may be formed on one side of the first separation region at a position perpendicular to the first inner separation region or the second inner separation region, in a direction crossing between the first inner separation region and the second inner separation region.

[0012] The third separation region may contain at least one substance among oxides, nitrides, and oxynitrides.

[0013] The third separation region may contain a substance different from that of the second separation region.

[0014] The second separation region may contain a substance having a refractive index higher than that of silicon.

[0015] The second separation region may contain polysilicon.

[0016] The third separation region may contain a substance having a refractive index lower than that of silicon.

[0017] The depth of the third separation region may be lower than the depth of the second separation region.

[0018] The third separation region may be formed to be in contact with the second separation region.

[0019] The third separation region may be formed to be separated from the second separation region.

[0020] According to one embodiment, an image sensing device is provided. The image sensing device includes a pixel array in which a plurality of unit pixels are arranged. The unit pixel includes a first sub-pixel including a green filter, a second sub-pixel including a red filter, and a third sub-pixel including a blue filter. A first separation region is formed in a boundary region of the first sub-pixel, a fourth separation region is formed in a boundary region of the second sub-pixel, a second separation region is formed in the first separation region in a direction toward a central portion of the first sub-pixel, and a fifth separation region is formed to protrude in the fourth separation region in a direction perpendicular to the direction in which the second separation region is formed. The second separation region includes a first inner separation region that protrudes in a direction toward a central portion of the first sub-pixel in a region of the first separation region, and a second inner separation region that is formed on the same straight line as the first inner separation region and protrudes in a direction toward a central portion of the first sub-pixel in another region of the first separation region. The fifth separation region includes a third inner separation region that protrudes in a direction toward a central portion of the second sub-pixel in a region of the fourth separation region, and a fourth inner separation region that is formed on the same straight line as the third inner separation region and protrudes in a direction toward a central portion of the second sub-pixel in another region of the fourth separation region. A third separation region may be formed in a direction orthogonal to a direction between the first inner separation region and the second inner separation region, and a sixth separation region may be formed in a direction orthogonal to a direction between the third inner separation region and the fourth inner separation region.

[0021] The first sub-pixel may include the first separation region, the second separation region including the first inner separation region and the second inner separation region, an insulating layer formed above the first separation region and the second separation region, the third separation region formed below the insulating layer, the green filter formed above the insulating layer, and a microlens formed above the green filter.

[0022] The first inner separation region may be formed at a position spaced apart from the second inner separation region by a certain distance.

[0023] The third separation region may be formed on one side of the first separation region at a position perpendicular to the first inner separation region or the second inner separation region, in a direction crossing between the first inner separation region and the second inner separation region.

[0024] The third separation region may contain at least one substance among oxide, nitride, and oxynitride.

[0025] The second sub-pixel may include the fourth separation region, the fifth separation region including the third inner separation region and the fourth inner separation region, an insulating layer formed on the upper portions of the fourth separation region and the fifth separation region, the sixth separation region formed under the insulating layer, a red filter formed on the upper portion of the insulating layer, and a microlens formed on the upper portion of the red filter.

[0026] The third inner separation region may be formed at a position spaced apart from the fourth inner separation region by a certain distance.

[0027] The sixth separation region may be formed on one side of the fourth separation region at a position perpendicular to the third inner separation region or the fourth inner separation region, in a direction crossing between the third inner separation region and the fourth inner separation region.

[0028] The sixth separation region may contain at least one substance among oxide, nitride, and oxynitride.

[0029] A seventh separation region is formed in the boundary region of the third sub-pixel, and an eighth separation region is formed to protrude in the seventh separation region in a direction perpendicular to the direction in which the second separation region is formed. The eighth separation region includes a fifth inner separation region that protrudes in the direction of the center of the third sub-pixel in one region of the seventh separation region, and a sixth inner separation region that is formed on the same straight line as the fifth inner separation region and protrudes in the direction of the center of the third sub-pixel in another region of the seventh separation region. A ninth separation region may be formed in a direction orthogonal to the direction between the fifth inner separation region and the sixth inner separation region.

[0030] The third sub-pixel may include the seventh separation region, the eighth separation region including the fifth inner separation region and the sixth inner separation region, an insulating layer formed on the upper portions of the seventh separation region and the eighth separation region, the ninth separation region formed below the insulating layer, a blue filter formed on the upper portion of the insulating layer, and a microlens formed on the upper portion of the blue filter.

[0031] The fifth inner separation region may be formed at a position spaced apart from the sixth inner separation region by a certain distance.

[0032] The ninth separation region may be formed on one side of the seventh separation region at a position perpendicular to the fifth inner separation region or the sixth inner separation region, in a direction crossing between the fifth inner separation region and the sixth inner separation region.

[0033] The ninth separation region may include at least one substance among oxides, nitrides, and oxynitrides.

Advantages of the Invention

[0034] By forming a light scattering region in a direction crossing between inner separation regions, light loss can be minimized and the output signal difference (Gr / Gb) between Gr pixels and Gb pixels of a Bayer pattern can be improved. That is, by forming a light scattering region in a direction crossing between inner separation regions, the difference between Gr and Gb can be minimized and Gr / Gb can be made closer to 1.

Brief Description of the Drawings

[0035]

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Mode for Carrying Out the Invention

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement them. However, the present invention can be implemented in various different forms and is not limited to the embodiments described herein. Also, in order to clearly explain the present invention in the drawings, parts not related to the explanation are omitted, and similar reference numerals are given to similar parts throughout the specification.

[0037] Throughout the specification, when a part states that a certain component "includes" something, this means that, unless otherwise stated to the contrary, it does not exclude other components but may further include other components.

[0038] The terms used in the embodiments of the present invention are generally the most widely used terms possible considering the functions in the present invention. However, these may change due to the intentions or precedents of those skilled in the art, the emergence of new technologies, etc. Also, in certain cases, there are terms arbitrarily selected by the applicant, and in such cases, the meaning will be described in detail in the explanatory part of the corresponding embodiment. Therefore, the terms used in this embodiment should be defined based not only on the simple name of the terms but also on the meaning of the terms and the overall content of this embodiment.

[0039] In the embodiments of the present invention, terms including ordinal numbers such as first, second, etc. can be used to describe various components, but the above components are not limited by the above terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the rights of the present invention, the first component can be named the second component, and similarly, the second component can be named the first component. The term "and / or" includes a combination of a plurality of related listed items or any one of a plurality of related listed items.

[0040] Also, in the embodiments of the present invention, a singular expression includes a plural expression unless the context clearly indicates otherwise.

[0041] FIG. 1 is a block diagram of an image sensing device according to an embodiment.

[0042] Referring to FIG. 1, an image sensing device according to an embodiment may include a pixel array (1100), a row driver (1200), a Correlate Double Sampler (CDS, 1300), an Analog-Digital Converter (ADC, 1400), an output buffer (1500), a column driver (1600), a timing controller (1700), and a bias generator (1800). Here, each component of the image sensing device is merely exemplary, and at least some components may be added or omitted as necessary.

[0043] The pixel array 1100 may include a plurality of pixels arranged in a plurality of rows and a plurality of columns. In one embodiment, the plurality of pixels may be arranged in a two-dimensional pixel array including rows and columns. In other embodiments, the plurality of unit image pixels may be arranged in a three-dimensional pixel array. The plurality of pixels can convert an optical signal into an electrical signal in pixel units or pixel group units, and the pixels within a pixel group can share at least a specific internal circuit. The pixel array 1100 can receive drive signals including a row selection signal, a pixel reset signal, a transmission signal, etc. from the row driver 1200, and according to the drive signals, the corresponding pixels of the pixel array 1100 can be activated to perform operations corresponding to the row selection signal, the pixel reset signal, and the transmission signal.

[0044] The load driver 1200 can activate the pixel array 1100 to perform specific operations on the pixels included in the corresponding row based on the instructions and control signals supplied by the timing controller 1700. In one embodiment, the load driver 1200 can select at least one pixel arranged in at least one row of the pixel array 1100. The load driver 1200 can generate a row selection signal to select at least one row among a plurality of rows. The load driver 1200 can sequentially enable a pixel reset signal and a transmission signal for the pixels corresponding to the selected at least one row. Thereby, the analog-type reference signal and the video signal generated from each of the pixels of the selected row can be sequentially transmitted to the correlation double sampler 1300. Here, the reference signal is an electrical signal provided to the correlation double sampler 1300 when the sensing node (e.g., floating diffusion node) of the pixel is reset, and the video signal can be an electrical signal provided to the correlation double sampler 1300 when the photoelectric charge generated by the pixel is accumulated in the sensing node. The reference signal indicating the pixel-specific reset noise and the video signal indicating the intensity of the incident light can be collectively referred to as pixel signals.

[0045] A CMOS image sensor can use correlated double sampling to remove unwanted offset values of pixels such as fixed pattern noise by sampling the pixel signal twice to remove the difference between two samples. As an example, correlated double sampling can remove unwanted offset values and measure the pixel output voltage based only on the incident light by comparing the pixel output voltages obtained before and after the photoelectric charge generated by the incident light is accumulated in the sensing node. In one embodiment, the correlated double sampler 1300 can sequentially sample and hold the reference signal and the video signal provided to each of the plurality of column lines from the pixel array 1100. That is, the correlated double sampler 1300 can sample and hold the levels of the reference signal and the video signal corresponding to each column of the pixel array 1100.

[0046] Based on the control signal from the timing controller 1700, the correlated double sampler 1300 can transmit the reference signal and the video signal of each column to the ADC 1400 as a correlated double sampling signal.

[0047] The ADC 1400 can convert the correlated double sampling signal for each column output from the correlated double sampler 1300 into a digital signal and output it. In one embodiment, the ADC 1400 can be implemented by a ramp-compare type ADC. The ramp-compare type ADC may include a comparison circuit that compares a ramp signal that rises or falls with time and an analog pixel signal, and a counter that performs a counting operation until the ramp signal matches the analog pixel signal. In one embodiment, the ADC 1400 can convert the correlated double sampling signal generated by the correlated double sampler 1300 for each column into a digital signal and output it.

[0048] The ADC 1400 may include a plurality of column counters corresponding to each column of the pixel array 1100. Each column of the pixel array 1100 is connected to each column counter, and video data can be generated by converting a correlated double sampling signal corresponding to each column into a digital signal using the column counter. In other embodiments, the ADC 1400 includes one global counter, and using the global code provided from the global counter, the correlated double sampling signal corresponding to each column can be converted into a digital signal.

[0049] The output buffer 1500 can temporarily hold and output the video data for each column provided by the ADC 1400. The output buffer 1500 can temporarily store the video data output from the ADC 1400 based on the control signal of the timing controller 1700. The output buffer 1500 can operate as an interface to compensate for the difference in transmission (or processing) speed between the image sensing device and other connected devices.

[0050] The column driver 1600 can select the column of the output buffer 1500 based on the control signal of the timing controller 1700, and control so that the video data temporarily stored in the selected column of the output buffer 1500 is output in order. In one embodiment, the column driver 1600 can receive an address signal from the timing controller 1700, and the column driver 1600 can generate a column selection signal based on the address signal to select the column of the output buffer 1500, thereby controlling so that the video data is output to the outside from the selected column of the output buffer 1500.

[0051] The timing controller 1700 can control at least one of the load driver 1200, the correlated double sampler 1300, the ADC 1400, the output buffer 1500, the column driver 1600, and the bias generator 1800.

[0052] The timing controller 1700 can provide at least one of a clock signal required for the operation of each component of the image sensing device, a control signal for timing control, an address signal for selecting a row or column, a signal for controlling the level of a bias voltage applied to the pixel array 1100, etc. to the load driver 1200, the correlated double sampler 1300, the ADC 1400, the output buffer 1500, the column driver 1600, and the bias generator 1800. According to one embodiment, the timing controller 1700 may include a logic control circuit, a phase lock loop (PLL) circuit, a timing control circuit, a communication interface circuit, etc.

[0053] The bias generator 1800 can generate a bias voltage for suppressing the dark current generated in the pixels of the pixel array 1100 and supply it to the pixel array 1100.

[0054] The bias voltage can be determined during the wafer probe test process of the image sensing device and stored in an OTP (One-Time Programmable) memory. For example, the bias voltage can be experimentally determined to be a value that can maximize the dark current suppression effect while not inhibiting the performance of the image sensing device and minimizing unnecessary power consumption.

[0055] The bias generator 1800 can generate a voltage corresponding to the bias voltage stored in the OTP memory. According to one embodiment, the OTP memory may be included in the image sensing device, particularly in the bias generator 1800.

[0056] According to one embodiment, the bias voltage may include a plurality of values.

[0057] For example, the plurality of values can each correspond to a plurality of operation modes of the image sensing device. The dark currents generated at low illuminance and high illuminance may be different from each other, and in order to effectively suppress the dark current in each environment, the bias voltage provided by the bias generator 1800 can vary depending on the mode.

[0058] Alternatively, the plurality of values can each correspond to a plurality of regions of the pixel array 1100. The dark currents generated depending on the pixel positions on the pixel array 1100 may be different from each other, and in order to effectively suppress the dark current regardless of the pixel positions, the bias voltage provided by the bias generator 1800 can vary depending on the region.

[0059] The bias voltage may be a negative voltage having a negative sign, but the scope of the present invention is not limited thereto.

[0060] FIG. 2 is a diagram for explaining a pixel array according to an embodiment. FIG. 3 is a diagram for explaining a first sub-pixel of the pixel array according to an embodiment.

[0061] Referring to FIG. 2, an image sensing device according to an embodiment may be a 2PD (Dual Photodiode) type image sensing device.

[0062] The pixel array 1100 can include, as an embodiment, a plurality of unit pixels, and the unit pixel may include a first sub-pixel 300 including a green filter, a second sub-pixel 400 including a red filter, and a third sub-pixel 500 including a blue filter.

[0063] Each unit pixel can include four sub-pixels including the same type of color filter, and two photodiodes may be formed below each color filter.

[0064] Referring to FIGS. 2 and 3, a first isolation region 310 may be formed in a boundary region of the first sub-pixels 300 (the boundary region between the first sub-pixels 300). The first isolation region 310 may be formed in a vertically deep groove shape to prevent crosstalk between the first sub-pixels 300 adjacent to each other, and may be formed through a deep trench isolation (DTI) process.

[0065] The first isolation region 310 may include at least one of a silicon oxynitride film (SiON), a silicon oxide film (SiO), a silicon nitride film (SiN), and polysilicon (Poly Si).

[0066] A second isolation region 320 may be formed inside the first isolation region 310. The second isolation region 320 may be formed in the direction of the center of the first sub-pixel 300 in the first isolation region 310.

[0067] The second isolation region 320 may be formed in a vertically deep groove shape to prevent crosstalk between adjacent photodiodes, and may be formed through a deep trench isolation (DTI) process.

[0068] The second isolation region 320 may include the same material as the first isolation region 310.

[0069] The second isolation region 320 may include a material having a refractive index higher than that of silicon (Si).

[0070] The second isolation region 320 may include at least one of a silicon oxynitride film (SiON), a silicon oxide film (SiO), a silicon nitride film (SiN), and polysilicon (Poly Si).

[0071] In one embodiment, the second isolation region 320 may include a first inner isolation region 321 and a second inner isolation region 322.

[0072] The first inner separation region 321 may be formed to protrude in the direction of the center of the first sub-pixel 300 in a region of the first separation region 310.

[0073] The second inner separation region 322 may be formed on the same straight line as the first inner separation region 321 and protrude in the direction of the center of the first sub-pixel 300 in another region of the first separation region 310 (the region opposite to the direction in which the first inner separation region 321 is formed).

[0074] As an embodiment, the first inner separation region 321 may be formed at a position spaced apart by a certain distance (space) from the second inner separation region 322.

[0075] A third separation region 330 may be formed between the first inner separation region 321 and the second inner separation region 322.

[0076] The third separation region 330 may be formed in a direction orthogonal to the space between the first inner separation region 321 and the second inner separation region 322.

[0077] One side of the third separation region 330 may be formed to be in contact with one side of the first separation region 310, and the other side of the third separation region 330 may be formed to be in contact with the other side of the first separation region 310.

[0078] The third separation region 330 may contain a substance different from that of the second separation region 320.

[0079] The third separation region 330 may contain a substance having a refractive index lower than that of silicon (Si).

[0080] As an embodiment, the third separation region 330 may contain an oxide.

[0081] As an embodiment, the third separation region 330 may contain at least one of an oxide, a nitride, and a oxynitride.

[0082] The third separation region 330 may have a different depth from the second separation region 320.

[0083] The depth of the third separation region 330 may be lower than the depth of the second separation region 320.

[0084] In one embodiment, an oxide layer (not shown) may be formed on the sidewall of the second separation region 320, and the third separation region 330 may be formed to be in contact with or separated from the oxide layer (not shown) of the second separation region 320.

[0085] FIG. 4 is a cross-sectional view taken along line A-A' of the first sub-pixel in FIG. 3. FIG. 5 is a cross-sectional view taken along line B-B' of the first sub-pixel in FIG. 3.

[0086] Referring to FIGS. 4 and 5, the first sub-pixel 300 may include a first separation region 310, a first inner separation region 321, a second inner separation region 322, a third separation region 330, a green filter 340, a photodiode 350, a filter layer separation region 360, a microlens 370, a substrate 380, and an insulating layer 390.

[0087] The first separation region 310 may be formed between adjacent first sub-pixels 300.

[0088] The first inner separation region 321 and the second inner separation region 322 may be formed below the insulating layer 390.

[0089] In one embodiment, the third separation region 330 may be formed below the insulating layer 390 and may be a region where at least one of oxide, nitride, and oxynitride is deposited in a groove of a region of the etched substrate 380. In one embodiment, the third separation region 330 may be thinly formed on the surface of the substrate 380.

[0090] As an embodiment, the third separation region 330 may be formed in a direction crossing between the first inner separation region 321 and the second inner separation region 322 on one side of the first separation region 310 at a position perpendicular to the first inner separation region 321 or the second inner separation region 322. As an embodiment, the first inner separation region 321, the second inner separation region 322, and the third separation region 330 may form a cross structure.

[0091] By forming the thin third separation region 330 in a direction crossing between the first inner separation region 321 and the second inner separation region 322, the scattered light can be diffused in both directions (up and down and left and right) instead of in one direction (up and down or left and right), thereby improving the output signal difference (Gr / Gb) between the Gr pixel and the Gb pixel of the bayer pattern. In addition, the light loss with respect to the cross-structured separation region (DTI) can be minimized, and Gr / Gb can be improved. In the case of the cross-structured separation region (DTI), light loss occurs due to light absorption.

[0092] The green filter 340 is formed on the upper part of the insulating layer 390, filters visible light from the light incident through the microlens 370 and allows it to pass through, and only green light can pass through the visible light.

[0093] The photodiode 350 is formed in the internal region of the substrate 380 and below the third separation region 330, and the N-type impurity region and the P-type impurity region may be laminated in the vertical direction. The N-type impurity region and the P-type impurity region may be formed through an ion implantation process.

[0094] The filter layer separation region 360 may be formed on the upper part of the first separation region 310.

[0095] The microlens 370 is formed on the upper part of the green filter 340 and serves to collect the light incident from the outside.

[0096] The substrate 380 may include a single-crystalline silicon (Si) material in one embodiment.

[0097] The insulating layer 390 is formed on top of the first isolation region 310 and the second isolation region 320 and may include at least one of an oxide, a nitride, and a oxynitride.

[0098] FIG. 6 is a diagram for explaining a second sub-pixel of a pixel array according to one embodiment.

[0099] Referring to FIGS. 2 and 6, a fourth isolation region 410 may be formed in a boundary region of the second sub-pixel 400 (the boundary region between the second sub-pixels 400). The fourth isolation region 410 may be formed in a vertically deep groove shape to prevent crosstalk between adjacent sub-pixels and may be formed through a deep trench isolation (DTI) process.

[0100] The fourth isolation region 410 may include at least one of a silicon oxynitride film (SiON), a silicon oxide film (SiO), a silicon nitride film (SiN), and polysilicon (Poly Si).

[0101] A fifth isolation region 420 may be formed inside the fourth isolation region 410. In the fourth isolation region 410, the fifth isolation region 420 may be formed in the direction of the center of the second sub-pixel 400.

[0102] The fifth isolation region 420 may be formed in a vertically deep groove shape to prevent crosstalk between adjacent photodiodes and may be formed through a deep trench isolation (DTI) process.

[0103] The fifth isolation region 420 may include the same material as the fourth isolation region 410.

[0104] The fifth separation region 420 may contain a substance having a refractive index higher than that of silicon (Si).

[0105] The fifth separation region 420 may contain at least one of a silicon oxynitride film (SiON), a silicon oxide film (SiO), a silicon nitride film (SiN), and polysilicon (Poly Si).

[0106] In one embodiment, the fifth separation region 420 may include a third inner separation region 421 and a fourth inner separation region 422.

[0107] The third inner separation region 421 may be formed to protrude toward the center of the second sub-pixel 400 in a region of the fourth separation region 410.

[0108] The fourth inner separation region 422 may be formed on the same straight line as the third inner separation region 421 and protrude toward the center of the second sub-pixel 400 in another region of the fourth separation region 410 (a region opposite to the direction in which the third inner separation region 421 is formed).

[0109] In one embodiment, the third inner separation region 421 may be formed at a position spaced apart from the fourth inner separation region 422 by a certain distance (space).

[0110] A sixth separation region 430 may be formed between the third inner separation region 421 and the fourth inner separation region 422.

[0111] The sixth separation region 430 may be formed in a direction orthogonal to the direction between the third inner separation region 421 and the fourth inner separation region 422.

[0112] One side of the sixth separation region 430 may be formed to be in contact with one side of the fourth separation region 410, and the other side of the sixth separation region 430 may be formed to be in contact with the other side of the fourth separation region 410.

[0113] The sixth separation region 430 may contain a substance different from that of the fifth separation region 420.

[0114] The sixth separation region 430 may contain a substance with a refractive index lower than that of silicon (Si).

[0115] The sixth separation region 430 may, in one embodiment, contain an oxide.

[0116] The sixth separation region 430 may, in one embodiment, contain at least one of an oxide, a nitride, and a oxynitride.

[0117] The sixth separation region 430 may have a different depth from the fifth separation region 420.

[0118] The depth of the sixth separation region 430 may be lower than the depth of the fifth separation region 420.

[0119] The fifth separation region 420 may, in one embodiment, have an oxide (Oxide) layer (not shown) formed on its sidewalls, and the sixth separation region 430 may be formed to be in contact with or separated from the oxide layer (not shown) of the fifth separation region 420.

[0120] FIG. 7 is a cross-sectional view taken along the line C-C' of the second sub-pixel in FIG. 6.

[0121] Referring to FIGS. 6 and 7, the second sub-pixel 400 may include a fourth separation region 410, a third inner separation region 421, a fourth inner separation region 422, a sixth separation region 430, a red filter 440, a photodiode 450, a filter layer separation region 460, a microlens 470, a substrate 480, and an insulating layer 490.

[0122] The fourth separation region 410 may be formed between adjacent sub-pixels.

[0123] The third inner separation region 421 and the fourth inner separation region 422 may be formed below the insulating layer 490.

[0124] The sixth isolation region 430 may be, as one embodiment, a region formed under the insulating layer 490 and having at least one of oxide, nitride, and oxynitride deposited in the grooves of a region of the etched substrate 480. The sixth isolation region 430 may be, as one embodiment, thinly formed on the surface of the substrate 480.

[0125] The sixth isolation region 430 may be, as one embodiment, formed on one side of the fourth isolation region 410 at a position perpendicular to the third inner isolation region 421 or the fourth inner isolation region 422, in a direction crossing between the third inner isolation region 421 and the fourth inner isolation region 422. As one embodiment, the third inner isolation region 421, the fourth inner isolation region 422, and the sixth isolation region 430 may form a cross structure.

[0126] By forming the thin sixth isolation region 430 in a direction crossing between the third inner isolation region 421 and the fourth inner isolation region 422, the scattered light can be diffused in both directions (up and down, and left and right) instead of in one direction (up and down or left and right), thereby improving Gr / Gb. Also, the light loss with respect to the cross-structured isolation region (DTI) can be minimized, and Gr / Gb can be improved. In the case of the cross-structured isolation region (DTI), light loss occurs due to light absorption.

[0127] The sixth isolation region 430 of the second sub-pixel 400 including the red filter 440 may be formed in a direction perpendicular to the direction in which the third isolation region 330 of the first sub-pixel 300 including the green filter 340 is formed.

[0128] The red filter 440 is formed on the upper part of the insulating layer 490, and can filter and pass visible light from the light incident through the microlens 470, allowing only red light to pass through as visible light.

[0129] The photodiode 450 is formed in the internal region of the substrate 480 and below the sixth isolation region 430, and the N-type impurity region and the P-type impurity region may be stacked vertically. The N-type impurity region and the P-type impurity region may be formed through an ion implantation process.

[0130] The filter layer separation region 460 may be formed above the fourth separation region 410.

[0131] The microlens 470 is formed above the red filter 440 and serves to collect light incident from the outside.

[0132] The substrate 480 may include a single-crystalline silicon (Si) material as an embodiment.

[0133] The insulating layer 490 is formed above the fourth separation region 410 and the fifth separation region 420 and may include at least one of an oxide, a nitride, and a oxynitride.

[0134] FIG. 8 is a diagram for explaining the third sub-pixel of the pixel array according to an embodiment.

[0135] Referring to FIGS. 2 and 8, a seventh separation region 510 may be formed in the boundary region of the third sub-pixel 500 (the boundary region between the third sub-pixels 500). The seventh separation region 510 may be formed in a vertically deep groove shape to prevent crosstalk between adjacent sub-pixels and may be formed through a deep trench isolation (DTI) process.

[0136] The seventh separation region 510 may include at least one of a silicon oxynitride film (SiON), a silicon oxide film (SiO), a silicon nitride film (SiN), and polysilicon (Poly Si).

[0137] An eighth isolation region 520 may be formed inside the seventh isolation region 510. The eighth isolation region 520 may be formed in the direction of the center of the third sub-pixel 500 in the seventh isolation region 510.

[0138] The eighth isolation region 520 may be formed in a vertically deep groove shape to prevent crosstalk between adjacent photodiodes, and may be formed through a deep trench isolation (DTI) process.

[0139] The eighth isolation region 520 may contain the same material as the seventh isolation region 510.

[0140] The eighth isolation region 520 may contain a material with a refractive index higher than that of silicon (Si).

[0141] The eighth isolation region 520 may contain at least one of silicon oxynitride film (SiON), silicon oxide film (SiO), silicon nitride film (SiN), and polysilicon (Poly Si).

[0142] As an embodiment, the eighth isolation region 520 may include a fifth inner isolation region 521 and a sixth inner isolation region 522.

[0143] The fifth inner isolation region 521 may be formed to protrude in the direction of the center of the third sub-pixel 500 in a region of the seventh isolation region 510.

[0144] The sixth inner isolation region 522 may be formed on the same straight line as the fifth inner isolation region 521, and may be formed to protrude in the direction of the center of the third sub-pixel 500 in another region of the seventh isolation region 510 (the region opposite to the direction in which the fifth inner isolation region 521 is formed).

[0145] As an embodiment, the fifth inner isolation region 521 may be formed at a position spaced apart from the sixth inner isolation region 522 by a certain distance (space).

[0146] A ninth separation region 530 may be formed between the fifth inner separation region 521 and the sixth inner separation region 522.

[0147] The ninth separation region 530 may be formed in a direction orthogonal to the direction between the fifth inner separation region 521 and the sixth inner separation region 522.

[0148] One side of the ninth separation region 530 may be formed to be in contact with one side of the seventh separation region 510, and the other side of the ninth separation region 530 may be formed to be in contact with the other side of the seventh separation region 510.

[0149] The ninth separation region 530 may contain a substance different from that of the eighth separation region 520.

[0150] The ninth separation region 530 may contain a substance with a refractive index lower than that of silicon (Si).

[0151] In one embodiment, the ninth separation region 530 may contain an oxide.

[0152] In one embodiment, the ninth separation region 530 may contain at least one of an oxide, a nitride, and a oxynitride.

[0153] The depth of the ninth separation region 530 may be different from that of the eighth separation region 520.

[0154] The depth of the ninth separation region 530 may be lower than the depth of the eighth separation region 520.

[0155] In one embodiment, an oxide layer (not shown) may be formed on the sidewalls of the eighth separation region 520, and the ninth separation region 530 may be formed to be in contact with or separated from the oxide layer (not shown) of the eighth separation region 520.

[0156] FIG. 9 is a cross-sectional view taken along the line D-D' of the third sub-pixel of FIG. 8.

[0157] Referring to FIG. 9, the third sub-pixel 500 may include a seventh separation region 510, a fifth inner separation region 521, a sixth inner separation region 522, a ninth separation region 530, a blue filter 540, a photodiode 550, a filter layer separation region 560, a microlens 570, a substrate 580, and an insulating layer 590.

[0158] The seventh separation region 510 may be formed between adjacent sub-pixels.

[0159] The fifth inner separation region 521 and the sixth inner separation region 522 may be formed below the insulating layer 590.

[0160] As one embodiment, the ninth separation region 530 may be formed below the insulating layer 590 and may be a region where at least one of oxide, nitride, and oxynitride is deposited in a groove of a region of the etched substrate 580. As one embodiment, the ninth separation region 530 may be thinly formed on the surface of the substrate 580.

[0161] As one embodiment, the ninth separation region 530 may be formed on one side of the seventh separation region 510 perpendicular to the fifth inner separation region 521 or the sixth inner separation region 522 and in a direction crossing between the fifth inner separation region 521 and the sixth inner separation region 522. As one embodiment, the fifth inner separation region 521, the sixth inner separation region 522, and the ninth separation region 530 may form a cross structure.

[0162] By forming the thin ninth separation region 530 in a direction crossing between the fifth inner separation region 521 and the sixth inner separation region 522, the scattered light can be diffused in both directions (up and down and left and right) instead of in one direction (up and down or left and right), thereby improving Gr / Gb. Also, the light loss with respect to the cross-structured separation region (DTI) can be minimized, and Gr / Gb can be improved. In the case of the cross-structured separation region (DTI), light loss occurs due to light absorption.

[0163] The ninth separation region 530 of the third sub-pixel 500 including the cyan filter 540 may be formed in a direction perpendicular to the direction in which the third separation region 330 of the first sub-pixel 300 including the green filter 340 is formed.

[0164] The cyan filter 540 is formed on the upper part of the insulating layer 590, filters visible light from the light incident through the microlens 570, and allows only cyan light to pass through as visible light.

[0165] The photodiode 550 is formed in the internal region of the substrate 580 and below the ninth separation region 530, and the N-type impurity region and the P-type impurity region may be laminated in the vertical direction. The N-type impurity region and the P-type impurity region may be formed through an ion implantation process.

[0166] The filter layer separation region 560 may be formed on the upper part of the seventh separation region 510.

[0167] The microlens 570 is formed on the upper part of the cyan filter 540 and serves to collect the light incident from the outside.

[0168] The substrate 580 may include a single-crystalline silicon (Si) material as an embodiment.

[0169] The insulating layer 590 is formed on the upper parts of the seventh separation region 510 and the eighth separation region 520, and may include at least one of an oxide, a nitride, and a oxynitride.

[0170] Although the embodiments of the present invention have been described in detail above, the scope of the rights of the present invention is not limited thereto, and many variations and improvements by those skilled in the art using the basic concept of the present invention defined in the following claims also belong to the scope of the rights of the present invention.

Claims

1. A pixel array in which a plurality of unit pixels are arranged, The unit pixel includes a plurality of sub-pixels, a first isolation region is formed in a boundary region of the subpixel; a second isolation region is formed in the first isolation region toward a center of the subpixel; The second isolation region is a first inner isolation region formed in a region of the first isolation region and protruding toward a center of the subpixel; a second inner isolation region formed in the same straight line as the first inner isolation region and protruding toward a center of the sub-pixel from another region of the first isolation region, The image sensing device, wherein a third isolation region is formed between the first inner isolation region and the second inner isolation region in a direction perpendicular to the first inner isolation region.

2. The sub-pixel comprises: The first isolation region; the second isolation region including the first inner isolation region and the second inner isolation region; an insulating layer formed on the first isolation region and the second isolation region; the third isolation region formed below the insulating layer; a color filter formed on the insulating layer; The image sensing device of claim 1 , further comprising a microlens formed on the color filter.

3. The second inner isolation region is The image sensing device of claim 1 , wherein the first inner isolation region is formed at a predetermined distance from the first inner isolation region.

4. The third isolation region is The image sensing device of claim 3 , wherein the inner isolation region is formed in a direction crossing between the first inner isolation region and the second inner isolation region on one side of the first isolation region at a position perpendicular to the first inner isolation region or the second inner isolation region.

5. The third isolation region is The image sensing device of claim 1 , comprising at least one of the following materials: an oxide, a nitride, and an oxynitride.

6. The image sensing device of claim 1 , wherein the third isolation region comprises a different material than the second isolation region.

7. The second isolation region is The image sensing device of claim 1 , comprising a material having a higher refractive index than silicon.

8. The second isolation region is The image sensing device of claim 1 comprising polysilicon.

9. The third isolation region is The image sensing device of claim 1 , comprising a material having a refractive index lower than that of silicon.

10. The image sensing device of claim 1 , wherein a depth of the third isolation region is less than a depth of the second isolation region.

11. The image sensing device according to claim 1 , wherein the third isolation region is formed to be in contact with the second isolation region.

12. The image sensing device of claim 1 , wherein the third isolation region is spaced apart from the second isolation region.

13. A pixel array in which a plurality of unit pixels are arranged, The unit pixel includes a first sub-pixel including a green filter, a second sub-pixel including a red filter, and a third sub-pixel including a blue filter, a first isolation region is formed in a boundary region of the first sub-pixel; a fourth isolation region is formed in a boundary region of the second sub-pixel; a second isolation region is formed in the first isolation region toward a center of the first sub-pixel; a fifth isolation region is formed in a direction perpendicular to a direction in which the second isolation region is formed, the fifth isolation region being formed by protruding from the fourth isolation region; The second isolation region is a first inner isolation region formed in a region of the first isolation region and protruding toward a center portion of the first sub-pixel; a second inner isolation region formed in the same straight line as the first inner isolation region and protruding toward a center portion of the first sub-pixel from another region of the first isolation region, The fifth isolation region is a third inner isolation region formed in a region of the fourth isolation region and protruding toward a center portion of the second sub-pixel; a fourth inner isolation region formed in the same straight line as the third inner isolation region and protruding toward a center portion of the second sub-pixel from another region of the fourth isolation region, a third isolation region is formed in a direction perpendicular to the first inner isolation region and the second inner isolation region; An image sensing device, wherein a sixth isolation region is formed between the third inner isolation region and the fourth inner isolation region in a direction perpendicular to the third inner isolation region.

14. The first subpixel is The first isolation region; the second isolation region including the first inner isolation region and the second inner isolation region; an insulating layer formed on the first isolation region and the second isolation region; the third isolation region formed below the insulating layer; the green filter formed on the insulating layer; The image sensing device of claim 13 , further comprising a microlens formed on the green filter.

15. The first inner isolation region is The image sensing device of claim 13 , wherein the second inner isolation region is formed at a predetermined distance from the second inner isolation region.

16. The third isolation region is The image sensing device of claim 15 , wherein the inner isolation region is formed in a cross direction between the first inner isolation region and the second inner isolation region on one side of the first isolation region at a position perpendicular to the first inner isolation region or the second inner isolation region.

17. The third isolation region is 14. The image sensing device of claim 13, comprising at least one of the following materials: an oxide, a nitride, and an oxynitride.

18. The second subpixel is The fourth isolation region; the fifth isolation region including the third inner isolation region and the fourth inner isolation region; an insulating layer formed on the fourth isolation region and the fifth isolation region; the sixth isolation region formed below the insulating layer; the red filter formed on the insulating layer; The image sensing device of claim 13 , further comprising a microlens formed on the red filter.

19. The third inner isolation region is The image sensing device of claim 13 , wherein the fourth inner isolation region is formed at a position spaced a predetermined distance from the fourth inner isolation region.

20. The sixth isolation region is The image sensing device of claim 19 , wherein the second inner isolation region is formed in a direction crossing between the third inner isolation region and the fourth inner isolation region on one side of the fourth isolation region at a position perpendicular to the third inner isolation region or the fourth inner isolation region.

21. The sixth isolation region is 14. The image sensing device of claim 13, comprising at least one of the following materials: an oxide, a nitride, and an oxynitride.

22. a seventh isolation region is formed in a boundary region of the third sub-pixel; an eighth isolation region is formed by protruding from the seventh isolation region in a direction perpendicular to a direction in which the second isolation region is formed; The eighth isolation region is a fifth inner isolation region formed in a region of the seventh isolation region and protruding toward a center portion of the third sub-pixel; a sixth inner isolation region formed in the same straight line as the fifth inner isolation region and protruding toward a center portion of the third sub-pixel from another region of the seventh isolation region; The image sensing device of claim 13 , wherein a ninth isolation region is formed in a direction perpendicular to the fifth inner isolation region and the sixth inner isolation region.

23. The third sub-pixel is The seventh isolation region; the eighth isolation region including the fifth inner isolation region and the sixth inner isolation region; an insulating layer formed on the seventh isolation region and the eighth isolation region; the ninth isolation region formed below the insulating layer; the blue filter formed on the insulating layer; 23. The image sensing device of claim 22, further comprising a microlens formed on top of the blue filter.

24. The fifth inner isolation region is The image sensing device of claim 22 , wherein the sixth inner isolation region is formed at a position spaced a predetermined distance from the sixth inner isolation region.

25. The ninth isolation region is The image sensing device of claim 24 , wherein the seventh isolation region is formed in a cross direction between the fifth inner isolation region and the sixth inner isolation region on one side of the seventh isolation region at a position perpendicular to the fifth inner isolation region or the sixth inner isolation region.

26. The ninth isolation region is 23. The image sensing device of claim 22, comprising at least one of the following materials: an oxide, a nitride, and an oxynitride.

Images