Image Sensor

Abstract

An image sensor may include: a pixel isolation structure, disposed in a semiconductor substrate, for defining a first pixel region; a first photoelectric conversion region and a second photoelectric conversion region, disposed in the first pixel region; and a separation structure, disposed in the first pixel region, between the first photoelectric conversion region and the second photoelectric conversion region. The pixel isolation structure may include: a first pixel isolation portion, spaced apart from each other in the second direction and extending longitudinally in the first direction; and a second pixel isolation portion, spaced apart from each other in the first direction and extending longitudinally in the second direction to be connected to the first pixel isolation portion. The separation structure may be spaced apart from the pixel isolation structure in the first direction and the second direction, and at least partially at the same level as the first photoelectric conversion region and the second photoelectric conversion region in a third direction perpendicular to the first direction and the second direction.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the priority of Korean Patent Application No. 10-2019-0011793 filed in the Korean Intellectual Property Office on January 30, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to an image sensor, and more particularly to an image sensor with an auto focus (AF) function. Background Art

[0004] Image sensors are devices that convert optical images into electrical signals. With the continuous development of the computer and communication industries, the demand for high-performance image sensors in various applications such as smartphones, wearable devices, digital cameras, personal communication systems, game consoles, security cameras, micro cameras for medical applications and / or robots is increasing.

[0005] Generally, image sensors can be classified into charge coupled device (CCD) sensors and complementary metal oxide semiconductor (CMOS) image sensors. Since CMOS image sensors can be operated in a simple manner and can be provided as a single chip integrated with a signal processing circuit, the size of products having CMOS image sensors can be reduced. In addition, due to its relatively low power consumption characteristics, CMOS image sensors are easily applied to electronic devices with limited battery capacity. In addition, the resolution of CMOS image sensors has increased with technological development, so the use of CMOS image sensors is growing rapidly. Summary of the invention

[0006] Embodiments of the inventive concept provide an image sensor having improved optical and electrical characteristics.

[0007] According to an embodiment of the present invention, an image sensor may include: a pixel isolation structure disposed in a semiconductor substrate to define a first pixel region; a first photoelectric conversion region and a second photoelectric conversion region disposed in the first pixel region; and a separation structure disposed in the first pixel region between the first photoelectric conversion region and the second photoelectric conversion region. The pixel isolation structure may include: a first pixel isolation portion spaced apart from each other in the second direction and extending longitudinally in the first direction; and a second pixel isolation portion spaced apart from each other in the first direction and extending longitudinally in the second direction to be connected to the first pixel isolation portion. The separation structure may be spaced apart from the pixel isolation structure in the first direction and the second direction, and at least partially at the same level as the first photoelectric conversion region and the second photoelectric conversion region in a third direction perpendicular to the first direction and the second direction.

[0008] According to an embodiment of the present inventive concept, an image sensor may include: a semiconductor substrate of a first conductive type; a pixel isolation structure disposed in the semiconductor substrate to define a first pixel region and a second pixel region; a first photoelectric conversion region and a second photoelectric conversion region, the first photoelectric conversion region and the second photoelectric conversion region being of a second conductive type and disposed in the semiconductor substrate of each of the first pixel region and the second pixel region; a first separation structure disposed in the first pixel region and between the first photoelectric conversion region and the second photoelectric conversion region of the first pixel region; and a separation impurity region disposed in the second pixel region and between the first photoelectric conversion region and the second photoelectric conversion region of the second pixel region. The separation impurity region extends in a first direction to intersect with the second pixel region, and the separation structure extends in the first direction and is spaced apart from the pixel isolation structure, and is at least partially at the same vertical level as the first photoelectric conversion region and the second photoelectric conversion region of the first pixel.

[0009] According to an embodiment of the inventive concept, an image sensor may include: a pixel isolation structure disposed in a semiconductor substrate to define a plurality of pixel regions, the pixel isolation structure surrounding each pixel region when viewed in a plan view; a first photoelectric conversion region and a second photoelectric conversion region disposed in each pixel region; and a separation structure disposed between the first photoelectric conversion region and the second photoelectric conversion region in a first pixel region among the pixel regions and spaced apart from the pixel isolation structure. The pixel isolation structure may include a first protruding portion, the first protruding portion protruding toward a center of a second pixel region among the pixel regions and facing each other in a first direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Example embodiments will be more clearly understood from the following brief description taken in conjunction with the accompanying drawings, which illustrate non-limiting example embodiments described herein.

[0011] Figure 1 is a block diagram illustrating an image sensor according to an embodiment of the inventive concept.

[0012] Figure 2 is a schematic plan view illustrating an image sensor according to an embodiment of the inventive concept.

[0013] Figure 3 is a circuit diagram illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0014] Figure 4A and Figure 4B is a plan view illustrating a color filter array of an image sensor according to some embodiments of the inventive concept.

[0015] Figure 5A , Figure 5C , Figure 5D and Figure 5E are plan views each illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0016] Figure 5B is an enlarged plan view illustrating a portion of an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0017] Fig. 6A , Figure 6B , Figure 6C and Fig.6D are along Figure 5A 1 and 2, cross-sectional views taken along lines II′, II-II′, and III-III′ illustrate an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0018] Fig. 7A , Figure 7B and Figure 7C are along Figure 5A 1 is a cross-sectional view taken along line II′ of FIG. 1 , illustrating an image sensor according to an embodiment of the inventive concept.

[0019] Fig. 8A , Fig.9A , Fig. 10A and Fig. 10C are plan views each illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0020] Figure 8B , Fig. 9B and Fig. 10B are along Fig. 8A , Fig.9A and Fig. 10A A cross-sectional view taken along line II′ of FIG. 1 illustrates an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0021] Fig.11A and Fig. 11B are a plan view and a cross-sectional view illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept, and Fig. 11B is along Fig.11A A cross-sectional view taken along line II′.

[0022] Fig. 12A , Fig. 12B , Fig. 12C and Fig.12D are plan views each illustrating an image sensor according to an embodiment of the inventive concept.

[0023] Fig.13A and Fig. 13B are plan views each illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0024] Fig.14A and Fig. 14B is along Fig.13A 2 and 3 , and are cross-sectional views taken along lines II′ and II-II′ of FIG. 1 , illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0025] Fig.15A , Fig. 15B , Fig. 15C and Fig.15D are plan views each illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0026] Fig.16A , Fig. 16B , Fig. 16C and Fig.16D are plan views each illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0027] Fig.17A , Fig. 17B and Fig. 17C is along Fig.16A 1 and 2, cross-sectional views taken along lines II′, II-II′, and III-III′ illustrate an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0028] Fig.18A , Fig.18B , Fig.18C , Fig.18D , Fig.18E and Fig.18F is a plan view illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0029] Fig.19A and Fig.19B is along Fig.19A 2 and 3 , and are cross-sectional views taken along lines II′ and II-II′ of FIG. 1 , illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0030] It should be noted that these drawings are intended to illustrate the general characteristics of the methods, structures and / or materials used in certain example embodiments and to supplement the written description provided below. However, these drawings are not to scale and may not accurately reflect the precise structure or performance characteristics of any given embodiment, and should not be interpreted as limiting or restricting the range of values ​​or properties contained in the example embodiments. For example, for clarity, the relative thickness and positioning of molecules, layers, regions and / or structural elements may be reduced or exaggerated. The use of similar or identical reference numerals in various drawings is intended to indicate the presence of similar or identical elements or features. DETAILED DESCRIPTION

[0031] Example embodiments of the inventive concepts will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments are shown.

[0032] Figure 1 is a block diagram illustrating an image sensor according to an embodiment of the inventive concept.

[0033] refer to Figure 1 , the image sensor may include an active pixel sensor array 1, a row decoder 2, a row driver 3, a column decoder 4, a timing generator 5, a correlated double sampler (CDS) 6, an analog-to-digital converter (ADC) 7 and an input / output (I / O) buffer 8.

[0034] The active pixel sensor array 1 may include a plurality of unit pixels arranged two-dimensionally for converting optical signals into electrical signals. The active pixel sensor array 1 may be driven by a plurality of driving signals (e.g., pixel selection signals, reset signals, and charge transfer signals) sent from a row driver 3. The converted electrical signals may be provided to a CDS 6.

[0035] In some embodiments, the image sensor can detect the phase difference of light to be incident into the active pixel sensor array 1, and can use the phase difference detection to perform an automatic focusing operation. Each unit pixel of the active pixel sensor array 1 can generate and output a focus signal according to the phase difference of light to be incident into a pair of photoelectric conversion devices. The focus signal can be used to perform an automatic focusing operation or to adjust the position of the lens of the imaging device.

[0036] The row driver 3 may provide a driving signal for driving a plurality of unit pixels to the active pixel sensor array 1 based on a result decoded by the row decoder 2. In the case where the unit pixels are arranged in a matrix shape, the driving signal may be provided to each row of the unit pixels.

[0037] The timing generator 5 may provide timing and control signals to the row decoder 2 and the column decoder 4 .

[0038] The CDS 6 may receive the electrical signal generated in the active pixel sensor array 1 and perform operations of holding and sampling the received electrical signal. For example, the CDS 6 may perform a double sampling operation on a specific noise level and a signal level of the electrical signal to output a difference level corresponding to the difference between the noise level and the signal level.

[0039] The ADC 7 may convert an analog signal corresponding to the difference level output from the CDS 6 into a digital signal, and may then output the converted digital signal to the I / O buffer 8 .

[0040] The I / O buffer 8 may latch the digital signal, and may sequentially output the latched digital signal to an image signal processing unit (not shown) based on the result of decoding by the column decoder 4 .

[0041] Figure 2 is a schematic plan view illustrating an image sensor according to an embodiment of the inventive concept.

[0042] refer to Figure 2 , the image sensor may include a pixel array region R1 and a pad region R2.

[0043] A plurality of unit pixels P may be arranged in the pixel array region R1, and the plurality of unit pixels P may be two-dimensionally arranged in two different directions (eg, a first direction D1 and a second direction D2, which may be a horizontal direction). Each unit pixel P of the pixel array region R1 may be configured to output an electrical signal generated by incident light.

[0044] The pixel array region R1 may include a central region CR and an edge region ER surrounding the central region CR. When viewed in a plan view, the edge region ER may be disposed at the top, bottom, right, and left sides of the central region CR.

[0045] The angle of light incident into the edge region ER of the pixel array region R1 may be different from the angle of light incident into the center region CR of the pixel array region R1 .

[0046] A plurality of conductive pads CP for inputting or outputting control signals and photoelectric signals may be provided in the pad region R2. When viewed in a plan view, the pad region R2 may be provided to surround the pixel array region R1, and this may enable the image sensor to be easily connected to an external device. In some embodiments, the edge region ER includes the unit pixels P of the image sensor that are closest to the pad of the pad region R2 and are adjacent to the pad of the pad region R2.

[0047] Figure 3 is a circuit diagram illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0048] Reference Figure 3 , the active pixel sensor array 1 may include a plurality of unit pixels P arranged in a row direction and a column direction or in a matrix shape. The unit pixel P may include a first photoelectric conversion device PD1 and a second photoelectric conversion device PD2, a first transfer transistor TX1 and a second transfer transistor TX2, and logic transistors RX, SX, and AX. Here, the logic transistor may include a reset transistor RX, a selection transistor SX, and an amplification transistor AX. The gate electrodes of the first transfer transistor TX1 and the second transfer transistor TX2, the reset transistor RX, and the selection transistor SX may be connected to the drive signal lines TG1, TG2, RG, and SG, respectively.

[0049] The first transfer transistor TX1 may include a first transfer gate TG1 and a first photoelectric conversion device PD1, and the second transfer transistor TX2 may include a second transfer gate TG2 and a second photoelectric conversion device PD2. The first and second transfer transistors TX1 and TX2 may share a charge detection node FD (eg, a floating diffusion region).

[0050] The first photoelectric conversion device PD1 and the second photoelectric conversion device PD2 can generate photocharges proportional to the amount of external incident light and then store the generated photocharges therein. Each of the first photoelectric conversion device PD1 and the second photoelectric conversion device PD2 can be provided in the form of a photodiode, a phototransistor, a photogate, a pinned photodiode (PPD), or any combination thereof.

[0051] The first transmission gate TG1 and the second transmission gate TG2 can be used to control the operation of transferring the photocharges stored in the first photoelectric conversion device PD1 and the second photoelectric conversion device PD2 to the charge detection node FD (e.g., a floating diffusion region). The first transmission gate TG1 and the second transmission gate TG2 can be applied with signals complementary to each other. The first transmission gate TG1 and the second transmission gate TG2 can be used to selectively transfer the photocharges from one of the first photoelectric conversion device PD1 and the second photoelectric conversion device PD2 to the charge detection node FD.

[0052] The photo charges transferred from the first photoelectric conversion device PD1 and the second photoelectric conversion device PD2 may be cumulatively stored in the charge detection node FD. The amplification transistor AX may be controlled by the amount of the photo charges stored in the charge detection node FD.

[0053] The reset transistor RX may be configured to periodically discharge or reset the photocharge stored in the charge detection node FD. For example, the reset transistor RX may include a drain electrode and a source electrode, and the drain electrode and the source electrode are respectively connected to the charge detection node FD and a node to which the power supply voltage VDD is applied. If the reset transistor RX is turned on, the power supply voltage VDD may be applied to the charge detection node FD through the source electrode of the reset transistor RX. Therefore, the photocharge stored in the charge detection node FD may be discharged to the power supply voltage VDD through the reset transistor RX, so that the charge detection node FD may be reset.

[0054] The amplifier transistor AX can amplify the change in the potential of the charge detection node FD, and can output the signal or pixel signal amplified by the selection transistor SX to the output line VOUT. The amplifier transistor AX can be a source follower buffer amplifier configured to generate a source-drain current in proportion to the amount of photocharge provided to its gate electrode. The gate electrode of the amplifier transistor AX can be connected to the charge detection node FD, the drain of the amplifier transistor AX can be connected to the power supply voltage VDD, and the source of the amplifier transistor AX can be connected to the drain of the selection transistor SX.

[0055] The selection transistor SX may be used to select a corresponding row of the unit pixel P for a read operation. If the selection transistor SX is turned on, the power supply voltage VDD applied to the drain electrode of the amplification transistor AX may be applied to the drain electrode of the selection transistor SX.

[0056] Figure 4A and Figure 4B is a plan view illustrating a color filter array of an image sensor according to some embodiments of the inventive concept.

[0057] refer to Figure 4A, the active pixel sensor array 1 may include color filters corresponding to the unit pixels respectively. Each unit pixel may include one of a red filter R, a green filter G, or a blue filter B. For example, the unit pixel may be a red pixel including a red filter R, a blue pixel including a blue filter B, or a green pixel including a green filter G. The red filter R of the red pixel may be configured to allow red light to pass through, and in this case, photoelectrons corresponding to the red light may be generated in the photoelectric conversion device of the red pixel. The blue filter R of the blue pixel may be configured to allow blue light to pass through, and in this case, photoelectrons corresponding to the blue light may be generated in the photoelectric conversion device of the blue pixel. The green filter R of the green pixel may be configured to allow green light to pass through, and in this case, photoelectrons corresponding to the green light may be generated in the photoelectric conversion device of the green pixel. In some embodiments, the unit pixels of the active pixel sensor array 1 may include magenta (Mg), yellow (Y), and cyan (Cy) filters.

[0058] As an example, the color filters R, G, and B may be arranged to form a Bayer pattern in which the number of green filters G is twice the number of red filters R or blue filters B. For example, the Bayer pattern may include color filter groups each including four color filters arranged in a 2×2 configuration, or including two green filters G arranged in one diagonal direction and a blue filter B and a red filter R arranged in another diagonal direction. Each of the red filter R and the blue filter B may be disposed between a pair of green filters G. The color filter groups of the Bayer pattern may be repeatedly arranged in the first direction D1 and the second direction D2.

[0059] refer to Figure 4B , the active pixel sensor array 1 may include color pixels and depth pixels. Each color pixel may include one of a red filter R, a green filter G, or a blue filter B. Each depth pixel may include an infrared filter Z that allows infrared light to pass.

[0060] The red filter R, the green filter G, the blue filter B, and the infrared filter Z may constitute a plurality of filter groups, the plurality of filter groups are repeatedly arranged in the first direction D1 and the second direction D2, and each filter group may include four filters arranged in a 2x2 configuration. In one embodiment, the depth pixel may be disposed between an adjacent pair of color pixels.

[0061] Light of different wavelengths may be incident on a unit pixel (or on a unit pixel) respectively. As described above, the color pixel may be configured to generate photoelectrons from visible light. The infrared filter Z of the depth pixel may be configured to allow infrared light to pass through, and the photoelectric conversion device of the depth pixel may be configured to generate photoelectrons from infrared light. By using a depth pixel that senses infrared light, the distance from the imaging device to the object may be calculated and a three-dimensional image of the object may be obtained.

[0062] Figure 5A , Figure 5C , Figure 5D and Figure 5E are plan views each illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept. Figure 5B is an enlarged plan view illustrating a portion of an active pixel sensor array of an image sensor according to an embodiment of the inventive concept. Fig. 6A , Figure 6B , Figure 6C and Fig.6D are along Figure 5A 1 and 2, cross-sectional views taken along lines II′, II-II′, and III-III′ illustrate an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0063] refer to Figure 5A and Figure 5B as well as FIG. 6A to FIG. 6D , an image sensor according to an embodiment of the inventive concept may include a photoelectric conversion layer 10, a readout circuit layer 20, and an optically transparent layer 30. When viewed in a cross-sectional view, the photoelectric conversion layer 10 may be disposed between the readout circuit layer 20 and the optically transparent layer 30. The optically transparent layer 30 may also be referred to as an optical conversion layer or an optical processing layer.

[0064] The photoelectric conversion layer 10 may include a semiconductor substrate 100 and a first photoelectric conversion region 110a and a second photoelectric conversion region 110b disposed in the semiconductor substrate 100. The semiconductor substrate 100 may have a first or front surface 100a and a second or rear surface 100b opposite to each other. The semiconductor substrate 100 may be of a first conductivity type, and the first photoelectric conversion region 110a and the second photoelectric conversion region 110b may be impurity regions doped with impurities of a second conductivity type (e.g., n-type) different from the first conductivity type. The first photoelectric conversion region 110a and the second photoelectric conversion region 110b may be configured to convert external incident light into an electrical signal.

[0065] The readout circuit layer 20 may be disposed on the first surface 100a of the semiconductor substrate 100. The readout circuit layer 20 may include a readout circuit (e.g., a MOS transistor) connected to the photoelectric conversion layer 10. The readout circuit layer 20 may perform a signal processing operation on the electrical signal converted by the photoelectric conversion layer 10. In detail, the MOS transistor and the wire 210 connected to the MOS transistor may be disposed on the first surface 100a of the semiconductor substrate 100. The wire 210 and the interlayer insulating layer 220 inserted between the wires 210 may be stacked on each other, and the wires 210 located at different levels may be connected to each other by contact plugs (e.g., conductive plugs, not shown).

[0066] The optical transparent layer 30 may be disposed on the second surface 100b of the semiconductor substrate 100. The optical transparent layer 30 may include a color filter array and a microlens array. The optical transparent layer 30 may be configured to perform optical processing operations or optical conversions, such as operations of concentrating and filtering light incident from the outside, and provide the light to the photoelectric conversion layer 10.

[0067] The color filter array may include a red filter 320R, a green filter 320G, and a blue filter 320B, as shown in FIG. Figure 4A In some embodiments, the color filter array may include filters of different colors (e.g., cyan, magenta, or yellow). In some embodiments, the color filter array may include an infrared filter, such as reference Figure 4B described.

[0068] The microlens array may include a plurality of microlenses 330 for concentrating light incident from the outside. When viewed in a plan view, the microlenses 330 may be two-dimensionally arranged in two different directions (eg, a first direction D1 and a second direction D2).

[0069] In one embodiment, the semiconductor substrate 100 may be a bulk silicon wafer of a first conductivity type (e.g., p-type) on which an epitaxial layer of the first conductivity type is provided. In one embodiment, the bulk silicon substrate may be removed during the manufacture of the image sensor, and in this case, the p-type epitaxial layer may be used as the semiconductor substrate 100. In some embodiments, the semiconductor substrate 100 may be a bulk semiconductor wafer in which a well of the first conductivity type is formed.

[0070] The semiconductor substrate 100 may include a plurality of pixel regions PG1, PG2, PB, and PR, which are defined by a pixel isolation structure 101. The pixel regions PG1, PG2, PB, and PR may be arranged in a matrix shape or in two different directions (e.g., a first direction D1 and a second direction D2). As an example, the plurality of pixel regions may include first to third pixel regions PG1, PG2, PB, and PR, and the light incident on the first to third pixel regions PG1, PG2, PB, and PR may have different wavelength ranges. In some embodiments, each pixel region includes a separate unit pixel or sensor element of an image sensor (e.g., the smallest addressable photosensitive element of an image sensor). Therefore, each pixel region PG1, PG2, PB, or PR may represent and may be referred to as a unit pixel or pixel.

[0071] In one embodiment, the first pixel regions PG1 and PG2 may be disposed adjacent to the second pixel region PB and the third pixel region PR in the first direction D1 and the second direction D2, respectively. The first pixel regions PG1 and PG2 may be arranged in a diagonal direction relative to each other. The second pixel region PB may be adjacent to the first pixel regions PG1 and PG2 in the first direction D1 and the second direction D2, and the third pixel region PR may be adjacent to the first pixel regions PG1 and PG2 in the first direction D1 and the second direction D2. Light of a first wavelength may be incident into the first pixel regions PG1 and PG2, and light having a second wavelength shorter than the first wavelength may be incident into the second pixel region PB. Light having a third wavelength longer than the first wavelength may be incident into the third pixel region PR. For example, green light may be incident into the first pixel regions PG1 and PG2, red light may be incident into the second pixel region PB, and blue light may be incident into the third pixel region PR. The different wavelengths of light may be generated by the filter used in the optically transparent layer 30.

[0072] When viewed in a plan view, the pixel isolation structure 101 may surround each of the first to third pixel regions PG1, PG2, PB, and PR. Figure 5BAs shown, the pixel isolation structure 101 may include: a plurality of first pixel isolation portions 101a extending in a first direction D1 (e.g., longitudinal direction) and spaced apart from each other in a second direction D2; and second pixel isolation portions 101b extending in a second direction D2 (e.g., longitudinal direction) to cross (e.g., intersect and connect) the first pixel isolation portions 101a and spaced apart from each other in the first direction D1. An article, layer, or portion of an article or layer described as extending "longitudinally" in a particular direction has a length in the particular direction and a width perpendicular to the direction, wherein the length is greater than the width. Each of the first pixel isolation portion 101a and the second pixel isolation portion 101b may have a first width W1. The distance L1 between the first pixel isolation portions 101a for each unit pixel may be the same as the distance between the second pixel isolation portions 101b for each unit pixel, but the present invention is not limited thereto. The pixel isolation portion may be referred to as a pixel isolation wall or a pixel isolation barrier.

[0073] Each of the first to third pixel regions PG1, PG2, PB, and PR may be defined by a pair of first pixel isolation portions 101a and a pair of second pixel isolation portions 101b. In one embodiment, the width of each of the first to third pixel regions PG1, PG2, PB, and PR may correspond to the distance between adjacent first pixel isolation portions 101a or the distance L1 between adjacent second pixel isolation portions 101b. It should be noted that the four pixel regions PG1, PG2, PB, and PR may be referred to as the first to fourth pixel regions, respectively, wherein the first pixel region PG1 and the second pixel region PG2 are pixel regions of the first type (e.g., including a first color filter), the third pixel region PB is a pixel region of the second type (e.g., including a second color filter), and the fourth pixel region PR is a pixel region of the third type (e.g., including a third color filter).

[0074] The pixel isolation structure 101 may be formed of an insulating material having a refractive index lower than that of the semiconductor substrate 100 (e.g., silicon), and may include one or more insulating layers. For example, the pixel isolation structure 101 may be formed of a silicon oxide layer, a silicon nitride layer, an undoped polysilicon layer, a gaseous material, or any combination thereof. The formation of the pixel isolation structure 101 may include: patterning the first surface 100a and / or the second surface 100b of the semiconductor substrate 100 to form a deep trench, and filling the deep trench with an insulating material.

[0075] The pixel isolation structure 101 may penetrate the semiconductor substrate 100. The vertical thickness of the pixel isolation structure 101 may be substantially the same as the vertical thickness of the semiconductor substrate 100. As another example, the pixel isolation structure 101 may vertically extend from the first surface 100a of the semiconductor substrate 100 toward the second surface 100b, and may be spaced apart from the second surface 100b of the semiconductor substrate 100, and thus may not extend all the way to the second surface 100b of the semiconductor substrate 100.

[0076] The pixel isolation structure 101 may have a first width (e.g., perpendicular to the longitudinal extension direction) near the first surface 100a of the semiconductor substrate 100, and a second width near the second surface 100b of the semiconductor substrate 100, the second width being greater than the first width. In addition, the width of the pixel isolation structure 101 may gradually decrease in a direction from the second surface 100b of the semiconductor substrate 100 toward the first surface 100a.

[0077] The pixel isolation structure 101 can prevent the photocharge generated by the incident light in each pixel region of the first pixel region to the third pixel region PG1, PG2, PB and PR from entering other pixel regions of the first pixel region to the third pixel region PG1, PG2, PB and PR adjacent to each pixel region through a random drift process. For example, the pixel isolation structure 101 can prevent the crosstalk phenomenon from occurring between adjacent pixel regions of the first pixel region to the third pixel region PG1, PG2, PB and PR.

[0078] In some embodiments, the first photoelectric conversion region 110a and the second photoelectric conversion region 110b are disposed in each pixel region of the first pixel region to the third pixel region PG1, PG2, PB, and PR. The first photoelectric conversion region 110a and the second photoelectric conversion region 110b may be impurity regions doped with impurities and have a second conductivity type (e.g., n-type) different from the first conductivity type of the semiconductor substrate 100. The first photoelectric conversion region 110a and the second photoelectric conversion region 110b and the semiconductor substrate 100 of the first conductivity type may constitute a pair of photodiodes. For example, the semiconductor substrate 100 and the first photoelectric conversion region 110a or the second photoelectric conversion region 110b may constitute a pn junction used as a photodiode. When light is incident on the first photoelectric conversion region 110a and the second photoelectric conversion region 110b constituting the photodiode, photocharges may be generated in proportion to the intensity of the incident light.

[0079] In each of the first to third pixel regions PG1, PG2, PB, and PR, there may be a phase difference between the electrical signals output from the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. In the image sensor, the phase difference between the electrical signals output from a pair of the first photoelectric conversion region 110a and the second photoelectric conversion region 110b may be used to calculate the distance to the object, to determine whether the object is in focus or out of focus, to determine the degree of defocus, and to automatically adjust the focus of the image sensor.

[0080] In each of the first to third pixel regions PG1, PG2, PB, and PR, separation structures 103, 105, and 107 may be disposed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. For example, each separation structure 103, 105, and 107 may be at least partially disposed at the same vertical level as the first photoelectric conversion region 110a and the second photoelectric conversion region 110b (e.g., in a third direction perpendicular to the first horizontal direction and the second horizontal direction). Separation structures 103, 105, and 107 may prevent light incident into the first photoelectric conversion region 110a from entering the second photoelectric conversion region 110b, and vice versa. For example, each of separation structures 103, 105, and 107 may prevent a crosstalk phenomenon between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b in a corresponding one of the first to third pixel regions PG1, PG2, PB, and PR. In one embodiment, each of the separation structures 103, 105, and 107 may be located at the center of a corresponding one of the pixel regions PG1, PG2, PB, and PR. In the present specification, the center of each pixel region PG1, PG2, PB, and PR may refer to a point that is equidistant from the adjacent first pixel isolation portion 101a and also equidistant from the adjacent second pixel isolation portion 101b. Each separation structure 103, 105, and 107 may be bilaterally symmetrical or radially symmetrical about the center of its corresponding pixel region.

[0081] In some embodiments, a first separation structure 103 may be disposed in each of the first pixel regions PG1 and PG2 , a second separation structure 105 may be disposed in the second pixel region PB, and a third separation structure 107 may be disposed in the third pixel region PR.

[0082] In detail, in each of the first pixel regions PG1 and PG2, the first separation structure 103 may be disposed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. When viewed in a plan view, the first separation structure 103 may have a linear shape extending in the second direction D2, and when viewed in a perspective view, the first separation structure 103 may have a plate shape. The first separation structure 103 may be disposed to extend longitudinally between the first pixel isolation portions 101a of the pixel isolation structure 101, and may be spaced apart from the first pixel isolation portions 101a of the pixel isolation structure 101. The length of the first separation structure 103 in the second direction D2 may be less than the distance L1 between the first pixel isolation portions 101a of the pixel isolation structure 101. The first separation structure 103 may have a second width W2 that is less than the first width W1 of the pixel isolation structure 101.

[0083] The first separation structure 103 may vertically extend from the second surface 100b toward the first surface 100a of the semiconductor substrate 100, and a vertical depth of the first separation structure 103 may be less than a vertical depth of the pixel isolation structure 101. The first separation structure 103 may be described as a first partition wall or barrier.

[0084] When viewed in a plan view, the second separation structure 105 may include: a first separation portion 105a extending in the second direction D2; and a second separation portion 105b extending in the first direction D1 and crossing or intersecting the first separation portion 105a. The second separation structure 105 may be spaced apart from the pixel isolation structure 101. The lengths L2 and L3 of the second separation structure 105 in the first direction D1 and the second direction D2 may be less than the distance L1 between the first pixel isolation portions 101a of the pixel isolation structure 101. In one embodiment, the length L2 of the first separation portion 105a in the second direction D2 may be equal to the length L3 of the second separation portion 105b in the first direction D1. Each of the first separation portion 105a and the second separation portion 105b of the second separation structure 105 may have a second width W2 that is less than the first width W1 of the pixel isolation structure 101.

[0085] In the second pixel region PB, the first separation portion 105a of the second separation structure 105 may be disposed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b, and the second separation portion 105b may partially overlap the first photoelectric conversion region 110a and the second photoelectric conversion region 110b when viewed in a plan view.

[0086] Since the second separation structure 105 includes the first separation portion 105a and the second separation portion 105b that cross each other, the light incident into the second pixel region PB can be reflected by the second separation structure 105 in both the first direction D1 and the second direction D2. Even if the incident light is reflected by the second separation structure 105 in a diffused manner, the amount of light propagating from the second pixel region PB toward the first pixel region PG1 adjacent thereto in the first direction D1 can be substantially equal to the amount of light propagating from the second pixel region PB toward the first pixel region PG2 adjacent thereto in the second direction D2. Therefore, it is possible to prevent or suppress the noise level from changing depending on the positions of the first pixel regions PG1 and PG2. In addition, since the second separation structure 105 is spaced apart from the pixel isolation structure 101, the diffuse reflection of the incident light that may be caused by the second separation structure 105 can be reduced.

[0087] The third separation structure 107 may be formed of a material having a different refractive index from the first and second separation structures 103 and 105, or may have a different shape from the first separation structure 103. The third separation structure 107 may be a separation impurity region doped with impurities and have the same conductivity type as the semiconductor substrate 100.

[0088] When viewed in a plan view, the third separation structure 107 may have a linear shape extending in the second direction D2 and may contact the pixel isolation structure 101. The articles described herein as "contacting" or "in contact with" each other are directly adjacent to each other and in contact. When viewed in a cross-sectional view, the third separation structure 107 may extend vertically from the second surface 100b of the semiconductor substrate 100 toward the first surface 100a. In one embodiment, when measured from the second surface 100b of the semiconductor substrate 100, the depth of the third separation structure 107 may be greater than the depth of the first separation structure 103 and the second separation structure 105.

[0089] Since the third separation structure 107 is formed by the impurity region of the first conductivity type, the third separation structure 107 can be used as a barrier between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. Therefore, it is possible to prevent the photocharge generated in the first photoelectric conversion region 110a from diffusing into the second photoelectric conversion region 110b, or to prevent the photocharge generated in the second photoelectric conversion region 110b from diffusing into the first photoelectric conversion region 110a. In addition, since the third separation structure 107 is formed of a semiconductor material similar to the first photoelectric conversion region 110a and the second photoelectric conversion region 110b, the light incident into the third pixel region PR may not be refracted by the third separation structure and may be reflected by the third separation structure, so the crosstalk phenomenon between the first pixel regions PG1 and PG2 adjacent to each other can be reduced. The crosstalk phenomenon that may occur between the third pixel region PR and the first pixel regions PG1 and PG2 adjacent thereto can become substantially the same in the first direction D1 and the second direction D2. For example, differences associated with crosstalk phenomena occurring in the first and second pixel regions RG1 and RG2 adjacent to the third pixel region PR in the first and second directions D1 and D2, respectively, may be reduced.

[0090] In each of the first pixel regions PG1 and PG2 , the first separation structure 103 may prevent a crosstalk phenomenon from occurring between the first photoelectric conversion region 110 a and the second photoelectric conversion region 110 b , and may reduce diffuse reflection of incident light caused by the first separation structure 103 .

[0091] The second separation structure 105 may reduce a crosstalk phenomenon occurring in the first direction D1 and the second direction D2 , and may reduce diffuse reflection of incident light caused by the second separation structure 105 .

[0092] The first and second separation structures 103 and 105 and the pixel isolation structure 101 may be formed simultaneously. For example, the first and second separation structures 103 and 105 may be formed by patterning the second surface 100b of the semiconductor substrate 100 to form trenches in the semiconductor substrate 100 and filling the trenches with an insulating material.

[0093] Since the second widths W2 of the first and second separation structures 103 and 105 are smaller than the first width W1 of the pixel isolation structure 101 , the vertical depths of the first and second separation structures 103 and 105 may be smaller than the vertical depth of the pixel isolation structure 101 .

[0094] The first separation structure 103 and the second separation structure 105 may include the same insulating material as the pixel isolation structure 101. The first separation structure 103 and the second separation structure 105 may be formed of an insulating material having a refractive index lower than that of the semiconductor substrate 100. For example, the first separation structure 103 and the second separation structure 105 may be formed of a silicon oxide layer, a silicon nitride layer, an undoped polysilicon layer, a gaseous material, or any combination thereof.

[0095] In addition, in each of the first pixel regions PG1, PG2, and the second pixel region PB, a dummy separation impurity region 102 may be disposed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b and below the first separation structure 103 and the second separation structure 105. The dummy separation impurity region 102 may be formed by implanting impurities having the same conductivity type (e.g., p-type) as the semiconductor substrate 100 into the semiconductor substrate 100 using an ion implantation process. Since the dummy separation impurity region 102 may function as a potential barrier, incident light may be separately provided to the first photoelectric conversion region 110a and the second photoelectric conversion region 110b.

[0096] In addition, according to some embodiments of the present inventive concept, in each of the first to third pixel regions PG1, PG2, PB, and PR, a diffusion region FD may be disposed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. In each of the first to third pixel regions PG1, PG2, PB, and PR, a floating diffusion region FD may be formed by implanting impurities of the second conductivity type into the first surface 100a of the semiconductor substrate 100 using, for example, an ion implantation process.

[0097] On the first surface 100 a of the semiconductor substrate 100 , the first transfer gate electrode TG1 may be disposed between the first photoelectric conversion region 110 a and the floating diffusion region FD, and the second transfer gate electrode TG2 may be disposed between the second photoelectric conversion region 110 b and the floating diffusion region FD.

[0098] In one embodiment, a portion of each of the first and second transfer gate electrodes TG1 and TG2 may be disposed in the semiconductor substrate 100 , and a gate insulating layer may be interposed between the first and second transfer gate electrodes TG1 and TG2 and the semiconductor substrate 100 .

[0099] The floating diffusion region FD may be disposed in the semiconductor substrate 100 between the first transfer gate electrode TG1 and the second transfer gate electrode TG2. The floating diffusion region FD may be formed by performing an ion implantation process in the semiconductor substrate 100 and may have a different conductivity type from the semiconductor substrate 100. For example, the floating diffusion region FD may be an n-type impurity region.

[0100] The interlayer insulating layer 220 may be stacked on the first surface 100a of the semiconductor substrate 100, and the interlayer insulating layer 220 may cover the MOS transistor constituting the readout circuit and the first transfer gate electrode TG1 and the second transfer gate electrode TG. The interlayer insulating layer 220 may include, for example, silicon oxide, silicon nitride and / or silicon oxynitride. The conductive wires 210 may be respectively disposed on the interlayer insulating layer 220, and the conductive wires 210 may be electrically connected to the readout circuit through contact plugs.

[0101] The color filters 320G, 320B, and 320R and the microlens 330 may be disposed on the second surface 100b of the semiconductor substrate 100. In addition, the planarization insulating layer 301 may be disposed between the second surface 100b of the semiconductor substrate 100 and the color filters 320G, 320B, and 320R. The color filters 320G, 320B, and 320R and the microlens 330 may be disposed to correspond to the first to third pixel regions PG1, PG2, PB, and PR, respectively.

[0102] The color filters 320G, 320B, and 320R may include red, green, or blue color filters, as shown in FIG. FIG. 4A to FIG. 4B Unlike this, the color filter may have other colors, such as cyan, magenta, or yellow. In an embodiment, the green filter 320G may be disposed on the first pixel regions PG1 and PG2, the blue filter 320B may be disposed on the second pixel region PB, and the red filter 320R may be disposed on the third pixel region PR.

[0103] Microlens 330 may have a convex shape and may be used to concentrate light incident into the first to third pixel regions PG1, PG2, PB, and PR. In an embodiment, each microlens 330 may overlap a pair of first and second photoelectric conversion regions 110a and 110b when viewed in a plan view.

[0104] The mesh pattern 310 may be disposed between the color filters 320G, 320B, and 320R. Similar to the pixel isolation structure 101, the mesh pattern 310 may have a mesh or net shape when viewed in a plan view. The separation pattern 310 may be formed of a metal material (eg, tungsten or aluminum).

[0105] according to Figure 5CIn the illustrated embodiment, in each of the first pixel regions PG1 and PG2, similar to the second separation structure 105, the first separation structure 103 may include: a first separation portion 103a extending along the second direction D2; and a second separation portion 103b extending along the first direction D1 and intersecting the first separation portion 103a.

[0106] according to Figure 5D In the illustrated embodiment, in the first to third pixel regions PG1, PG2, PB and PR, each of the first to third separation structures 103, 105 and 107 may include: a first separation portion 103a, 105a or 107a extending in the second direction D2; and a second separation portion 103b, 105b or 107b extending in the first direction D1 and intersecting the first separation portion 103a, 105a or 107a.

[0107] according to Figure 5E In the embodiment shown, in each of the first pixel regions PG1 and PG2, the first separation structure 103 may be disposed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. When viewed in a plan view, the first separation structure 103 may have a linear shape extending in the second direction D2. Each of the second separation structure 105 and the third separation structure 107 may be a separation impurity region that is of the first conductivity type and is disposed in the semiconductor substrate 100 between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b.

[0108] In the following embodiments, for the sake of brevity, previously described elements may be identified by the same reference numerals without repeating their redundant descriptions.

[0109] Fig. 7A , Figure 7B and Figure 7C Each is along Figure 5A 1 is a cross-sectional view taken along line II′ of FIG. 1 , illustrating an image sensor according to an embodiment of the inventive concept.

[0110] Reference Fig. 7A , the pixel isolation structure 101 may include: a first insulating layer 111 covering the inner surface of the deep trench with a constant thickness (for example, it may be conformally formed along the surface of the semiconductor substrate 100 where the trench is formed); and a second insulating layer 113 filling the trench with the first insulating layer 111. The first insulating layer 111 and the second insulating layer 113 may be formed of different materials.

[0111] The pixel isolation structure 101 may extend vertically from the second surface 100b of the semiconductor substrate 100 toward the first surface 100a, and the bottom surface of the pixel isolation structure 101 may be spaced apart from the first surface 100a of the semiconductor substrate 100. Thus, the depth of the pixel isolation structure 101 may be less than the thickness of the semiconductor substrate 100.

[0112] The first separation structure 103 and the second separation structure 105 may be formed of the same material as the first insulating layer 111 of the pixel isolation structure 101 .

[0113] Reference Figure 7B , the pixel isolation structure 101 may include a first refractive layer 112 and a second refractive layer 114 having different refractive indices from each other. The first refractive layer 112 may be in contact with the semiconductor substrate 100, and the second refractive layer 114 may be disposed in the first refractive layer 112. Due to the difference in refractive index, light obliquely incident to the pixel isolation structure 101 may be refracted at an interface of the first refractive layer 112 and the second refractive layer 114. For example, the first refractive layer 112 may be formed of an insulating material (e.g., silicon oxide or silicon nitride), and the second refractive layer 114 may be formed of or include a polysilicon layer or a metal layer. The first separation structure 103 and the second separation structure 105 may be formed of the same material as the first reflective layer 112 of the pixel isolation structure 101.

[0114] Reference Figure 7C , the pixel isolation structure 101 may have a first width near the first surface 100a of the semiconductor substrate 100, and a second width near the second surface 100b of the semiconductor substrate 100, where the second width may be smaller than the first width. In addition, the width of the pixel isolation structure 101 may gradually decrease in a direction from the first surface 100a of the semiconductor substrate 100 toward the second surface 100b.

[0115] Fig. 8A , Fig.9A , Fig. 10A and Fig. 10C are plan views each illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept. Figure 8B , Fig. 9B and Fig. 10B are along Fig. 8A , Fig.9A and Fig. 10A 1 is a cross-sectional view taken along line II′ of FIG. 1 , illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0116] As described above, the first separation structure 103 may be disposed in each of the first pixel regions PG1 and PG2 , the second separation structure 105 may be disposed in the second pixel region PB, and the third separation structure 107 may be disposed in the third pixel region PR.

[0117] Reference Fig. 8A and Figure 8B , the first separation structure 103 may include: a first separation portion 103a extending along the second direction D2; and a second separation portion 103b intersecting the first separation portion 103a, extending in the first direction D1 and having a protruding shape. Here, one of the first separation portion 103a and the second separation portion 103b may be spaced apart from the pixel isolation structure 101, and the other of the first separation portion 103a and the second separation portion 103b may be connected to the pixel isolation structure 101. The longitudinal axis length L3 of the second separation portion 103b may be shorter than the longitudinal axis length L2 of the first separation portion 103a.

[0118] The first separation portion 103a may extend in the second direction D2, may be located between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b, and may be connected to the first pixel isolation portion 101a of the pixel isolation structure 101. The first separation portion 103a may have a length L2, which is equal to a distance L1 between the first pixel isolation portion 101a when measured in the second direction D2 (e.g., see Figure 5B ). The first separation portion 103a may be arranged to intersect each of the first pixel regions PG1 and PG2, and may be used to reduce the crosstalk problem between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. The second separation portion 103b of the first separation structure 103 may provide a cross structure extending between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b, which is similar to the cross structure of the first pixel isolation portion 101a and the second pixel isolation portion 101b of the pixel isolation structure 101. Incident light may be incident on the center of each of the first pixel regions PG1 and PG2, and the incident light may be reflected by the first separation structure 103 or may be separated by the first separation structure 103 in the first direction D1 and the second direction D2.

[0119] In addition, since the first separation structure 103 is spaced apart from the pixel isolation structure 101 in the first direction D1, the incident light may not be reflected in the portion between the pixel isolation structure 101 and the second separation portion 103b of the first separation structure 103, and the incident light may be absorbed by the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. Therefore, the amount of light incident into the first photoelectric conversion region 110a and the second photoelectric conversion region 110b may be increased, and this may increase the difference between the signals output from the first photoelectric conversion region 110a and the second photoelectric conversion region 110b of each pixel region PG1, PG2, PB, and PR. By comparing the signals output from the first photoelectric conversion region 110a and the second photoelectric conversion region 110b, the operating characteristics in the autofocus operation of controlling the lens position may be improved.

[0120] Since the pixel isolation structure 101 has a cross structure formed by the first pixel isolation portion 101a and the second pixel isolation portion 101b intersecting each other, the pixel isolation structure 101 may have a maximum depth at a region where the first pixel isolation portion 101a and the second pixel isolation portion 101b intersect each other. In addition, when the pixel isolation structure 101 and the first separation structure 103 and the second separation structure 105 are formed simultaneously, substantially the same process environment may be provided to the central portion of each pixel region PG1, PG2, PB, and PR.

[0121] The second separation structure 105 may include a first separation portion 105a and a second separation portion 105b, the first separation portion 105a intersecting the second pixel region PB in the second direction D2, and the second separation portion 105b intersecting the second pixel region PB in the first direction D1. The second separation portion 105b of the second separation structure 105 may intersect the first separation portion 105a and the first pixel region PG1 and the second pixel region PG2 and PB. The second separation structure 105 may reduce the difference between the crosstalk between the pixel regions adjacent to each other in the first direction D1 and the crosstalk between the pixel regions adjacent to each other in the second direction D2.

[0122] As described above, when viewed in a plan view, the third separation structure 107 may extend in the second direction D2, and may be a separation impurity region that is of the first conductivity type and is disposed in the semiconductor substrate 100 between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. Light incident into the third pixel region PR may be separately provided to the first photoelectric conversion region 110a and the second photoelectric conversion region 110b through a potential barrier without a diffuse reflection problem caused by the third separation structure 107. Therefore, a crosstalk phenomenon that may occur between the third pixel region PR and the first pixel regions PG1 and PG2 adjacent thereto may become substantially the same in the first direction D1 and the second direction D2.

[0123] refer to Fig.9A and Fig. 9B , the second separation structure 105 and the third separation structure 107 may be identical in terms of their structures and materials. In detail, when viewed in a plan view, the second separation structure 105 and the third separation structure 107 may extend in the second direction D2, and may be a separation impurity region that is of the first conductivity type and is disposed in the semiconductor substrate 100 between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. In each of the second pixel region PB and the third pixel region PR, a crosstalk phenomenon may occur in a symmetrical manner in the first direction D1 and the second direction D2.

[0124] Reference Fig. 10A and Fig. 10B , in each of the first pixel regions PG1 and PG2, the first separation structure 103 may be spaced apart from the pixel isolation structure 101 in both the first direction D1 and the second direction D2. Therefore, light may be provided to the first photoelectric conversion region 110a and the second photoelectric conversion region 110b without diffuse reflection at the edge portion of each of the first pixel regions PG1 and PG2. In addition, in the second pixel region PB, the second separation structure 105 may be spaced apart from the pixel isolation structure 101 in both the first direction D1 and the second direction D2.

[0125] Reference Fig. 10CIn each of the first pixel regions PG1 and PG2, the first separation structure 103 may be spaced apart from the pixel isolation structure 101, and the first separation structure 103 may include: a first separation portion 103a extending in the second direction D2; and a second separation portion 103b extending from the first separation portion 103a and having a shape extending and protruding in the first direction D1. When viewed in a plan view, the second separation structure 105 of the second pixel region PB and the third separation structure 107 of the third pixel region PR may extend in the second direction D2 and may be a separation impurity region that is of the first conductivity type and is disposed in the semiconductor substrate 100 between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b.

[0126] Fig.11A and Fig. 11B are a plan view and a cross-sectional view illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept. Fig. 11B is along Fig.11A A cross-sectional view taken along line II′. Fig. 12A , Fig. 12B , Fig. 12C and Fig.12D are plan views each illustrating an image sensor according to an embodiment of the inventive concept.

[0127] As described above, the first separation structure 103 may be disposed in each of the first pixel regions PG1 and PG2 , the second separation structure 105 may be disposed in the second pixel region PB, and the third separation structure 107 may be disposed in the third pixel region PR.

[0128] Reference Fig.11A and Fig. 11B as well as FIG. 12A to FIG. 12C , the pixel isolation structure 101 may include a first pixel isolation portion 101a extending along the first direction D1, a second pixel isolation portion 101b extending along the second direction D2, and a protruding portion 101P protruding from the first pixel isolation portion 101a. Here, the protruding portion 101P may protrude toward the center of the third pixel region PR or along the second direction D2. As another example, Fig.12D As shown, the protruding portion 101P of the pixel isolation structure 101 may be disposed in each of the second pixel region PB and the third pixel region PR. In each of the second pixel region PB and the third pixel region PR, the protruding portion 101P of the pixel isolation structure 101 may be disposed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b, and may have a shape that protrudes in the second direction D2.

[0129] When viewed in a plan view, the third separation structure 107 may be disposed between the protruding portions 101P of the pixel isolation structure 101 and may extend in the second direction D2. The third separation structure 107 may be a separation impurity region that is of the first conductivity type and is disposed in the semiconductor substrate 100 between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. The length of the third separation structure 107 in the second direction D2 may be less than the distance between the first pixel isolation portions 101a of the pixel isolation structure 101.

[0130] The protruding portion 101P of the pixel isolation structure 101 can prevent the degradation of each junction formed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b of the third pixel region PR and a portion adjacent to the pixel isolation structure 101. In addition, the protruding portion 101P of the pixel isolation structure 101 can physically reflect incident light at the edge of the third pixel region PR, so the crosstalk phenomenon between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b can be reduced in the third pixel region PR.

[0131] In addition, the first separation structure 103 and the second separation structure 105 may be spaced apart from the pixel isolation structure 101 in the first direction D1 and the second direction D2. Fig.11A and Fig. 11B Here, the first separation structure 103 may have a linear structure, and the second separation structure 105 may have a cross structure.

[0132] As another example, the first separation structure 103 and the second separation structure 105 may be connected to the pixel isolation structure 101, such as Fig. 12A In other words, the first separation structure 103 may be disposed to cross the first pixel regions PG1 and PG2 in the second direction D2. The second separation structure 105 may be disposed to cross the second pixel region PB in the first direction D1 and the second direction D2.

[0133] As another example, the first separation structure 103 may include a first separation portion 103a and a second separation portion 103b, wherein the first separation portion 103a extends in the second direction D2 and is connected to the pixel isolation structure 101, and the second separation portion 103b is disposed across the first separation portion 103a and is spaced apart from the pixel isolation structure 101. Fig. 12B and Fig. 12C Here, Fig. 12B As shown, the second separation structure 105 may cross the second pixel region PB in the first direction D1 and the second direction D2, and may be connected to the pixel isolation structure 101. Fig. 12CAs shown, the second separation structure 105 may include a first separation portion 105 a and a second separation portion 105 b that cross each other, but may be spaced apart from the pixel isolation structure 101 .

[0134] Fig.13A and Fig. 13B are plan views each showing an active pixel sensor array of an image sensor according to an embodiment of the inventive concept. Fig.14A and Fig. 14B is along Fig.13A 2 and 3 , and are cross-sectional views taken along lines II′ and II-II′ of FIG. 1 , illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0135] Reference Fig.13A , Fig.14A and Fig. 14B , the pixel isolation structure 101 may include a first pixel isolation portion 101a extending along the first direction D1, a second pixel isolation portion 101b extending along the second direction D2, and a protrusion portion 101P protruding from the first pixel isolation portion 101a. Here, each protrusion portion 101P may protrude toward the center of a corresponding one of the first to third pixel regions PG1, PG2, PB, and PR or along the second direction D2.

[0136] The protruding portion 101P of the pixel isolation structure 101 may be disposed in each of the first to third pixel regions PG1, PG2, PB, and PR. In each of the first to third pixel regions PG1, PG2, PB, and PR, the protruding portion 101P of the pixel isolation structure 101 may be disposed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b, and may have a shape that protrudes in the second direction D2.

[0137] In the first pixel regions PG1 and PG2, the first separation structure 103 may be disposed between the protruding portions 101P of the pixel isolation structure 101. Fig.13A and Fig. 13B Here, the first separation structure 103 may include a first separation portion 103a extending along the second direction D2, and a second separation portion 103b extending along the first direction D1 and crossing the first separation portion 103a, as shown in FIG. Fig.13A Alternatively, the first separation structure 103 may have a linear shape extending in the second direction D2, as shown in FIG. Fig. 13B shown.

[0138] In the second pixel region PB, as Fig.13A and Fig. 13BAs shown, the second separation structure 105 may be disposed between the protruding portions 101P of the pixel isolation structure 101 , and may include a first separation portion 105 a and a second separation portion 105 b crossing each other.

[0139] In the third pixel region PR, the third separation structure 107 may be a separation impurity region which is of the first conductivity type and is disposed in the semiconductor substrate 100 between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. Fig.13A and Fig. 13B Here, the separation impurity region may be disposed between the protruding portions 101P of the pixel isolation structure 101 .

[0140] Fig.15A , Fig. 15B , Fig. 15C and Fig.15D are plan views each illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0141] As described above, the first separation structure 103 may be disposed in each of the first pixel regions PG1 and PG2 , the second separation structure 105 may be disposed in the second pixel region PB, and the third separation structure 107 may be disposed in the third pixel region PR.

[0142] Reference FIG. 15A to FIG. 15D , the pixel isolation structure 101 may include a first pixel isolation portion 101a extending along the first direction D1, a second pixel isolation portion 101b extending along the second direction D2, a first protruding portion 101Pa protruding from the first pixel isolation portion 101a along the second direction D2, and a second protruding portion 101Pb protruding from the second pixel isolation portion 101b along the first direction D1. Here, the first protruding portion 101Pa and the second protruding portion 101Pb may have a shape that partially protrudes toward the center of each of the first to third pixel regions PG1, PG2, PB, and PR. In each of the first to third pixel regions PG1, PG2, PB, and PR, the protruding portion 101P of the pixel isolation structure 101 may be disposed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b.

[0143] Reference Fig.15A , Fig. 15B and Fig.15D, in each of the first pixel regions PG1 and PG2, the first separation structure 103 may include a first separation portion 103a and a second separation portion 103b that cross each other. The first separation portion 103a of the first separation structure 103 may be disposed between the first protruding portions 101Pa of the pixel isolation structure 101, and the second separation portion 103b of the first separation structure 103 may be disposed between the second protruding portions 101P of the pixel isolation structure 101. Alternatively, the first separation structure 103 may have a line shape extending along the second direction D2 between the first protruding portions 101Pa of the pixel isolation structure 101, as shown in FIG. Fig. 15C shown.

[0144] Reference Fig.15A , Fig. 15C and Fig.15D In the third pixel region PR, the third separation structure 107 may be a separation impurity region that is of the first conductivity type and is disposed in the semiconductor substrate 100 between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. Here, the separation impurity region may be disposed between the protruding portions 101P of the pixel isolation structure 101.

[0145] according to FIG. 15A to FIG. 15D In the embodiment shown, in each of the first to third pixel regions PG1, PG2, PB, and PR, light may be reflected by the first to third separation structures 103, 105, and 107, and may be separately provided to the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. In addition, since light may be incident into the region between the first to third separation structures 103, 105, and 107 and the pixel isolation structure 101, the amount of light absorbed into the first photoelectric conversion region 110a and the second photoelectric conversion region 110b may be increased.

[0146] Fig.16A , Fig. 16B , Fig. 16C and Fig.16D are plan views each illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept. Fig.17A , Fig. 17B and Fig. 17C is along Fig.16A 1 and 2, cross-sectional views taken along lines II′, II-II′, and III-III′ illustrate an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0147] Reference Fig.16A , Fig.17A , Fig. 17B and Fig. 17C, the first to fourth photoelectric conversion regions 110a, 110b, 110c, and 110d may be disposed in each of the first to third pixel regions PG1, PG2, PB, and PR. The first to fourth photoelectric conversion regions 110a, 110b, 110c, and 110d may be impurity regions doped with impurities and having a second conductivity type (e.g., n-type) different from the conductivity type of the semiconductor substrate 100. In each of the first to third pixel regions PG1, PG2, PB, and PR, the first to fourth photoelectric conversion regions 110a, 110b, 110c, and 110d may be spaced apart from each other in the first direction D1 and the second direction D2.

[0148] Reference Fig.16A and Fig. 16B In each of the first pixel regions PG1 and PG2, the first separation structure 1.03 can be set between the first photoelectric conversion region to the fourth photoelectric conversion region 110a, 110b, 110c and 110d, and in the second pixel region PB, the second separation structure 105 can be set between the first photoelectric conversion region to the fourth photoelectric conversion region 110a, 110b, 110c and 110d.

[0149] Reference Fig.16A , in the third pixel region PR, a first separated impurity region extending along the second direction D2 and a second separated impurity region extending along the first direction D1 may be provided in the semiconductor substrate 100. The first separated impurity region may be provided between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b and between the third photoelectric conversion region 110c and the fourth photoelectric conversion region 110d. The second separated impurity region may be provided between the first photoelectric conversion region 110a and the third photoelectric conversion region 110c and between the second photoelectric conversion region 110b and the fourth photoelectric conversion region 110d. The pixel isolation structure 101 may include a first protruding portion 101Pa protruding from the first pixel isolation portion 101a in the second direction D2, and a second protruding portion 101Pb protruding from the second pixel isolation portion 101b in the first direction D1, as shown in reference Fig.15A described.

[0150] In each of the first to third pixel regions PG1, PG2, PB, and PR, the first protruding portion 101Pa of the pixel isolation structure 101 may be disposed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b and between the third photoelectric conversion region 110c and the fourth photoelectric conversion region 110d. The first protruding portion 101Pb of the pixel isolation structure 101 may be configured between the first photoelectric conversion region 110a and the third photoelectric conversion region 110c and between the second photoelectric conversion region 110b and the fourth photoelectric conversion region 110d.

[0151] exist Fig. 16C In the embodiment of Fig.16A The pixel isolation structure 101 includes a first protruding portion 101Pa and a second protruding portion 101Pb.

[0152] Reference Fig. 16B , in the third pixel region PR, the third separation structure 107 may be disposed between the first to fourth photoelectric conversion regions 110a, 110b, 110c, and 110d, and the third separation structure 107 may have the same material and structure as the first separation structure 103 and the second separation structure 105. That is, the first to fourth photoelectric conversion regions 110a, 110b, 110c, and 110d may be disposed in each of the first to third pixel regions PG1, PG2, PB, and PR, and the first to third separation structures 103, 105, and 107 may include first separation portions 103a, 105a, and 107a and second separation portions 103b, 105b, and 107b disposed to cross each other. In addition, the pixel isolation structure 101 may include a first protruding portion 101Pa protruding from the first pixel isolation portion 101a in the second direction D2, and a second protruding portion 101Pb protruding from the second pixel isolation portion 101b in the first direction D1, as shown in FIG. Fig.15A described.

[0153] refer to Fig.16D , can be omitted Fig. 16B The pixel isolation structure 101 includes a first protruding portion 101Pa and a second protruding portion 101Pb.

[0154] Fig.18A , Fig.18B , Fig.18C , Fig.18D , Fig.18E and Fig.18F is a plan view illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept. Fig.19A and Fig.19B is along Fig.19A 2 and 3 , and are cross-sectional views taken along lines II′ and II-II′ of FIG. 1 , illustrating an active pixel sensor array of an image sensor according to an embodiment of the inventive concept.

[0155] Reference Fig.18A , Fig.19A and Fig.19B , the planar position of the first to third separation structures 103, 105 and 107 in each of the first to third pixel regions PG1, PG2, PB and PR can be changed according to the position of the first to third pixel regions PG1, PG2, PB and PR in the active pixel sensor array.

[0156] As previously referenced Figure 2 As described above, the pixel array region R1 may include a central region CR and an edge region ER. In the first to third pixel regions PG1, PG2, PB, and PR disposed in the edge region ER, the first to third separation structures 103, 105, and 107 may be shifted toward the central region CR, as shown in FIG. Fig.18A and Fig.18B shown.

[0157] For details, refer to Fig.18A and Fig.18B , when viewed in a plan view, the center C1 of the first separation structure 103 may be offset relative to the center PC1 of each of the first pixel regions PG1 and PG2, and the center C2 of the second separation structure 105 may be offset relative to the center PC2 of the second pixel region PB. Here, the center C1 of the first separation structure 103 may be an intersection point of the first separation portion 103a and the second separation portion 103b, and the center C2 of the second separation structure 105 may be an intersection point of the first separation portion 105a and the second separation portion 105b.

[0158] like Fig.18A and Fig.18B As shown, the first separation structures 103 may be positioned differently from each other in terms of distances from corresponding ones of the first pixel isolation portions 101a in the first direction D1. Fig.18A and Fig.18B As shown, the first separation structures 103 may be positioned differently from each other in terms of distances from corresponding ones of the first pixel isolation portions 101 a in the first direction D1.

[0159] In addition, if Fig.18A and Fig.18BAs shown, when viewed in a plan view, the microlenses 330 disposed to correspond to the pixel regions PG1, PG2, PB, and PR, respectively, may be shifted toward the central region CR of the pixel array region R1 (eg, see Figure 2 ). When viewed in a plan view, the center MC of the microlens 330 may be offset relative to a corresponding one of the centers PC1 and PC2 of the pixel area. Alternatively, when viewed in a plan view, the center MC of the microlens 330 may be offset relative to the center C1 of the first separation structure 103.

[0160] The horizontal distance between the center MC of the microlens 330 and the center PC1 or PC2 of each pixel region PG1, PG2, PB, and PR may be substantially equal to the horizontal distance between the center of the first separation structure 103 and the center PC1 or PC2 of each of the first pixel regions PG1 and PG2. Alternatively, the horizontal distance between the center MC of the microlens 330 and the center PCI or PC2 of each pixel region PG1, PG2, PB, and PR may be different from the horizontal distance between the center of the first separation structure 103 and the center C1 of the first separation structure 103 and the center PCI of each of the first pixel regions PG1 and PG2.

[0161] Reference Fig.18A , in the edge region ER of the pixel array region R1 (see, for example, Figure 2 ), the centers of the first separation structure 103 and the second separation structure 105 may be offset relative to the centers of the first pixel regions PG1, PG2 and the second pixel region PB, respectively, and the center of the third separation structure 107 composed of the separation impurity regions is not offset relative to the center of the third pixel region PR.

[0162] When viewed in a plan view, the center of the first separation structure 103 may be spaced apart from the center of each of the first pixel regions PG1 and PG2 by a first horizontal distance. When viewed in a plan view, the center of the second separation structure 105 may be spaced apart from the center of the second pixel region PB by a second horizontal distance that is substantially equal to the first horizontal distance.

[0163] A horizontal distance between a center of the second pixel region PB and a center of the second separation structure 105 in the second pixel region PB may be different from a horizontal distance between a center of each of the first pixel regions PG1 and PG2 and a center of the first separation structure 103 in the first pixel regions PG1 and PG2 .

[0164] Reference Fig.18B, centers of the first to third separation structures 103 , 105 , and 107 may be offset with respect to centers of the first to third pixel regions PG1 , PG2 , PB, and PR, respectively.

[0165] In addition, reference Fig.18A and Fig.18B , the pixel isolation structure 101 may include a first pixel isolation portion 101a and a second pixel isolation portion 101b and a first protruding portion 101Pa and a second protruding portion 101Pb. Fig.18A In the embodiment, the first protrusion portion 101Pa and the second protrusion portion 101Pb may locally protrude toward the center of each pixel region. Fig.18B , the first protrusion portion 101Pa and the second protrusion portion 101Pb may partially protrude toward the center of each of the separation structures 103 , 105 , and 107 .

[0166] refer to Fig.18C and Fig.18D , can be omitted Fig.18A and Fig.18B The first protruding portion 101Pa and the second protruding portion 101Pb of the pixel isolation structure 101 are formed. In each first pixel region PG1, the first separation structure 103 may be disposed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. In the second pixel region PB, the second separation structure 105 including the first separation portion 105a and the second separation portion 105b intersecting each other may be disposed between the first photoelectric conversion region 110a and the second photoelectric conversion region 110b. In the edge region ER of the pixel array region R1 (for example, see Figure 2 ), the centers of the first separation structure 103 and the second separation structure 105 may be offset relative to the centers of the first pixel region PG1, PG2 and the second pixel region PB, respectively. In addition, when viewed in a plan view, the microlenses 330 disposed to correspond to the pixel regions PG1, PG2, PB and PR, respectively, may be oriented toward (e.g., Figure 2 The central area CR of the pixel array area R1 is shifted.

[0167] Reference Fig.18E and Fig.18F , the first to fourth photoelectric conversion regions 110a, 110b, 110c, and 110d may be disposed in each of the first to third pixel regions PG1, PG2, PB, and PR.

[0168] Reference Fig.18EA first separation structure 103 or a second separation structure 105 including first and second separation portions 103a and 103b or 105a and 105b crossing each other may be provided in each of the first pixel regions PG1, PG2 and the second pixel region PB. Fig.18F A first separation structure 103 or a second separation structure 105 including first and second separation portions 103a and 103b or 105a and 105b crossing each other may be disposed in each of the first and third pixel regions PG1, PG2, PB, and PR.

[0169] As mentioned above, in (e.g., Figure 2 In the edge region ER of the pixel array region R1, Fig.18E and Fig.18D The centers of the first to third separation structures 103, 105, and 107 shown may be offset relative to the centers of the first pixel regions PG1, PG2, and the second pixel region PB, respectively. In addition, when viewed in a plan view, the microlenses 330 disposed corresponding to the pixel regions PG1, PG2, PB, and PR, respectively, may be oriented (e.g., Figure 2 The central area CR of the pixel array area R1 is shifted.

[0170] According to an embodiment of the present invention, the separation structure between the first photoelectric conversion region and the second photoelectric conversion region can reduce the difference between the crosstalk between the pixel regions adjacent to each other in the first direction and the crosstalk between the pixel regions adjacent to each other in the second direction. Therefore, it is possible to prevent or suppress the noise level from changing depending on the position of the pixel region. In addition, since the separation structure is spaced apart from the pixel isolation structure, light can be incident on the first photoelectric conversion region and the second photoelectric conversion region between the separation structure and the pixel isolation structure. Therefore, the amount of light incident on the first photoelectric conversion region and the second photoelectric conversion region can be increased, and this can increase the difference between the signals output from the first photoelectric conversion region and the second photoelectric conversion region of each pixel region. By comparing the signals output from the first photoelectric conversion region and the second photoelectric conversion region, the operating characteristics in the automatic focusing operation of controlling the lens position can be improved.

[0171] In short, according to embodiments of the inventive concept, crosstalk characteristics in each pixel region may be improved and auto-focus operation characteristics of an image sensor may be improved.

[0172] While exemplary embodiments of the present inventive concept have been particularly shown and described, it will be understood by those skilled in the art that changes in form and details may be made without departing from the spirit and scope of the appended claims.

[0173] For ease of description, spatially relative terms, such as "front," "rear," "below," "above," "on," etc., may be used herein to describe the relationship of one element or feature to another element or features as shown in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation shown in the drawings. For example, if the device in the drawings is turned over, elements described as "below" or "beneath" other elements or features would be oriented "above" the other elements or features. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may be interpreted accordingly.

[0174] In addition, ordinals such as "first", "second", "third", etc. may simply be used as labels for certain elements, steps, etc. to distinguish these elements, steps, etc. from each other. Terms that are not described using "first", "second", etc. in the specification may still be referred to as "first" or "second" in the claims. In addition, a term referenced with a specific ordinal number (e.g., "first" in a specific claim) may be described elsewhere with a different ordinal number (e.g., "second" in the specification or another claim).

[0175] Terms such as "same", "equal", "planar" or "coplanar" used herein when referring to orientation, layout, position, shape, size, amount or other measurement do not necessarily mean exactly the same orientation, layout, position, shape, size, amount or other measurement, but are intended to include nearly the same orientation, layout, position, shape, size, amount or other measurement, such as within acceptable variations that may occur due to manufacturing processes. Unless the context or other statements indicate otherwise, the term "substantially" may be used herein to emphasize this meaning. For example, items described as "substantially the same", "substantially equal" or "substantially planar" may be exactly the same, equal or planar, or may be the same, equal or planar within acceptable variations that may occur, such as due to manufacturing processes.

Claims

1. An image sensor, include: A pixel isolation structure, disposed in the semiconductor substrate, for defining a first pixel region; A first photoelectric conversion region and a second photoelectric conversion region are arranged in the first pixel region; as well as A separation structure is provided in the first pixel region between the first photoelectric conversion region and the second photoelectric conversion region, The pixel isolation structure includes: first pixel isolation parts that are spaced apart from each other in the second direction and extend longitudinally in the first direction; and second pixel isolation parts that are spaced apart from each other in the first direction and extend longitudinally in the second direction to be connected to the first pixel isolation parts, and wherein the separation structure is spaced apart from the pixel isolation structure in the first direction and the second direction, wherein the first photoelectric conversion region and the second photoelectric conversion region are spaced apart from each other in the second direction, wherein each of the first photoelectric conversion region and the second photoelectric conversion region has a first length in the first direction, The separation structure includes: a first separation portion, which is arranged between the first photoelectric conversion region and the second photoelectric conversion region and has a longitudinal axis parallel to the first direction; and a second separation portion, which intersects the first separation portion and has a longitudinal axis parallel to the second direction. The length of the longitudinal axis of the first separation portion is smaller than the first length, and the length of the longitudinal axis of the second separation portion is smaller than or equal to the length of the longitudinal axis of the first separation portion.

2. The image sensor according to claim 1, in, Each of the first pixel isolation portion and the second pixel isolation portion of the pixel isolation structure has a first width, and The separation structure has a second width that is smaller than the first width.

3. The image sensor according to claim 1, in, The pixel isolation structure has a first depth from a first surface of the semiconductor substrate, and The separation structure has a second depth that is less than the first depth.

4. The image sensor according to claim 1, in, The pixel isolation structure and the separation structure are formed of the same insulating material.

5. The image sensor according to claim 4, in, The separation structure is located at different distances from each of the second pixel isolation portions in the second direction, and is located at different distances from each of the first pixel isolation portions in the first direction.

6. The image sensor according to claim 1, in, When viewed in a plan view, a center of the separation structure is offset relative to a center of the first pixel region.

7. The image sensor according to claim 1, further comprising a microlens disposed on the first surface of the semiconductor substrate, in, When viewed in a plan view, a center of the microlens is offset from a center of the first pixel region.

8. The image sensor according to claim 1, further comprising a microlens disposed on the first surface of the semiconductor substrate, in, When viewed in a plan view, a center of the microlens and a center of the separation structure are offset relative to a center of the first pixel region.

9. An image sensor, include: a semiconductor substrate of a first conductivity type; A pixel isolation structure, disposed in the semiconductor substrate, for defining a first pixel region and a second pixel region; a first photoelectric conversion region and a second photoelectric conversion region, the first photoelectric conversion region and the second photoelectric conversion region being of a second conductivity type and being disposed in the semiconductor substrate in each of the first pixel region and the second pixel region; a first separation structure disposed in the first pixel region and between the first photoelectric conversion region and the second photoelectric conversion region in the first pixel region, the first separation structure being formed of an insulating material; as well as a second separation structure formed by a separation impurity region, disposed in the second pixel region and between the first photoelectric conversion region and the second photoelectric conversion region in the second pixel region, wherein the second separation structure does not include the insulating material, wherein the separated impurity region extends longitudinally in a first direction to intersect with the second pixel region, The first separation structure extends longitudinally in the first direction and is spaced apart from the pixel isolation structure. The first separation structure includes: a first separation portion, which is arranged between the first photoelectric conversion region and the second photoelectric conversion region of the first pixel region and has a longitudinal axis parallel to the first direction; and a second separation portion, which intersects the first separation portion and has a longitudinal axis parallel to a second direction intersecting the first direction, and Wherein, when measured in the first direction, the length of the longitudinal axis of the first separation portion is less than the length of the separation impurity region, and the length of the longitudinal axis of the second separation portion is less than or equal to the length of the longitudinal axis of the first separation portion.

10. The image sensor according to claim 9, in, The semiconductor substrate further includes a third pixel region defined by the pixel isolation structure, The image sensor further includes a third separation structure disposed between the first photoelectric conversion region and the second photoelectric conversion region disposed in the third pixel region, and The third separation structure is formed of the same material as one of the first separation structure and the separation impurity region.

11. The image sensor according to claim 10, in, The third separation structure is formed of the same material as the first separation structure, and The third separation structure includes a first separation portion and a second separation portion, which are spaced apart from the pixel isolation structure and disposed to cross each other.

12. The image sensor according to claim 10, in, The first pixel region is disposed adjacent to the second pixel region in the first direction, and is disposed adjacent to the third pixel region in the second direction.

13. The image sensor according to claim 10, in, When viewed in a plan view, a center of the first separation structure is spaced apart from a center of the first pixel region by a first horizontal distance, and When viewed in a plan view, a center of the third separation structure is spaced apart from a center of the third pixel region by a second horizontal distance, the second horizontal distance being different from the first horizontal distance.

14. The image sensor according to claim 10, in, When viewed in a plan view, a center of the first separation structure is spaced apart from a center of the first pixel region by a first horizontal distance, and When viewed in a plan view, a center of the third separation structure is spaced apart from a center of the third pixel region by the first horizontal distance.

15. The image sensor according to claim 9, further comprising: include: a third photoelectric conversion region and a fourth photoelectric conversion region, the third photoelectric conversion region and the fourth photoelectric conversion region being of the second conductivity type and being disposed in the semiconductor substrate of each of the first pixel region and the second pixel region, The first separation structure is arranged between the first photoelectric conversion region to the fourth photoelectric conversion region of the first pixel region, and The separation impurity region is disposed between the first photoelectric conversion region to the fourth photoelectric conversion region of the second pixel region.

16. An image sensor, include: a pixel isolation structure disposed in the semiconductor substrate and used to define a plurality of pixel regions, wherein the pixel isolation structure surrounds each pixel region when viewed in a plan view; A first photoelectric conversion region and a second photoelectric conversion region are provided in each pixel region; as well as a separation structure, disposed between the first photoelectric conversion region and the second photoelectric conversion region in a first pixel region among the pixel regions and spaced apart from the pixel isolation structure, The pixel isolation structure includes a first protruding portion, which protrudes toward a center of a second pixel region among the pixel regions and faces each other in a first direction.

17. The image sensor according to claim 16, in, The separation structure has a linear shape extending in the first direction, The pixel isolation structure has a first width, and The separation structure and the first protruding portion have a second width, and the second width is smaller than the first width.

Images