Image Sensor

Abstract

To provide an image sensor capable of preventing saturation of electric charges generated from a photodiode and accumulated while securing an autofocus function for four directions.SOLUTION: An image sensor 100 comprises a pixel array that includes a plurality of first pixel groups PG1 and a plurality of second pixel groups PG2 alternately arranged in a direction parallel to an upper surface of a substrate, each pixel group including a plurality of unit pixels PX arranged in 4×4 in the direction. Each of the plurality of first and second pixel groups includes an element isolation film DTI arranged between the plurality of unit pixels, a photodiode arranged inside the substrate in each of the plurality of unit pixels, and a color filter. Each of the plurality of unit pixels included in the plurality of first pixel groups includes a first micro-lens ML1 arranged above the color filter. The plurality of unit pixels included in the plurality of second pixel groups include a second micro-lens ML2 shared for each 2×2 arrangement.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an image sensor. [Background technology]

[0002] An image sensor is a semiconductor-based sensor that receives light and generates an electrical signal, and includes a pixel array having a plurality of unit pixels and a circuit for driving the pixel array to generate an image. The plurality of unit pixels includes a photodiode that generates an electric charge in response to external light, and a pixel circuit that converts the electric charge generated by the photodiode into an electric signal. Image sensors are widely used in cameras for taking photos and videos, as well as smartphones, tablet PCs, laptop computers, TVs, automobiles, etc. Recently, research into improving autofocus performance and generating images with high image quality has been ongoing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-22728 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made in view of the above-mentioned conventional technology, and an object of the present invention is to provide an improved image sensor that prevents saturation of the charge generated and accumulated in the photodiode while ensuring autofocus function in four directions, and further generates images with high image quality. [Means for solving the problem]

[0005] In order to achieve the above object, according to one aspect of the present invention, an image sensor includes a substrate having a first surface and a second surface facing each other in a first direction, and is arranged in a 4×4 pattern in a second direction parallel to an upper surface of the substrate and a third direction perpendicular to the second direction. , sharing one floating diffusion region per 2x2 array. the pixel array includes a plurality of unit pixels, each of which includes a plurality of first pixel groups and a plurality of second pixel groups alternately arranged in the second direction and the third direction; and a logic circuit configured to acquire pixel signals from the plurality of unit pixels, wherein the plurality of first pixel groups and the plurality of second pixel groups include an isolation film disposed between the plurality of unit pixels, a photodiode disposed inside the substrate in each of the plurality of unit pixels, and a color filter disposed on the first surface, each of the plurality of unit pixels included in the plurality of first pixel groups includes a first microlens disposed on top of the color filter, and the plurality of unit pixels included in the plurality of second pixel groups include a second microlens shared by each of the unit pixels in a 2x2 arrangement, and each of the plurality of second pixel groups includes an overflow region for transferring charge generated from the photodiode to an adjacent photodiode.

[0006] According to another aspect of the present invention, there is provided an image sensor including: a pixel array including a plurality of sub-pixel groups arranged in a 2×2 pattern in a second direction parallel to an upper surface of a substrate having a first surface and a second surface facing each other in a first direction, and in a third direction perpendicular to the second direction, the sub-pixel groups each including a plurality of unit pixels sharing one floating diffusion region for each of the 2×2 arrays; and a logic circuit configured to acquire pixel signals from the plurality of unit pixels, wherein each of the plurality of sub-pixel groups is adjacent to one of the first sub-pixel groups and one of the second sub-pixel groups in the second direction and the third direction, and the floating diffusion region is disposed between the plurality of unit pixels. the plurality of unit pixels include isolation films separated from each other in the second direction and the third direction in a region adjacent to a pixel diffusion region, a photodiode disposed inside the substrate in each of the plurality of unit pixels, and a color filter disposed on the first surface, each of the plurality of unit pixels included in the plurality of first sub-pixel groups includes a first microlens disposed on an upper portion of the color filter, and each of the plurality of second sub-pixel groups includes a second microlens shared by the plurality of unit pixels included in the plurality of second sub-pixel groups, and a separation length of the isolation films included in the plurality of first sub-pixel groups in the second direction and the third direction is shorter than a separation length of the isolation films included in the plurality of second sub-pixel groups.

[0007] According to another aspect of the present invention, there is provided an image sensor including: an isolation layer extending in a first direction perpendicular to an upper surface of a substrate; and photodiodes arranged in a 4×4 pattern along a second direction parallel to an upper surface of the substrate and a third direction perpendicular to the second direction, the photodiodes being disposed within the substrate. Each 2x2 array shares one floating diffusion region.The pixel array includes a plurality of unit pixels, each including a plurality of first pixel groups and a plurality of second pixel groups alternately arranged in the second direction and the third direction; and a logic circuit that acquires pixel signals from the plurality of unit pixels, wherein a plurality of first microlenses having a first diameter and corresponding to each of the plurality of unit pixels are arranged on an upper surface of the plurality of first pixel groups, and a plurality of second microlenses having a second diameter larger than the first diameter are arranged on an upper surface of the plurality of second pixel groups, and the pixel signals acquired from unit pixels sharing each of the plurality of second microlenses include autofocus pixel signals for the second direction and the third direction. [Effects of the Invention]

[0008] The image sensor of the present invention can generate images with higher image quality than conventional image sensors by using a first microlens corresponding to each of the plurality of photodiodes and a second microlens shared by the plurality of photodiodes to ensure four-way autofocusing functionality. The image sensor also includes an overflow region for transferring excessively generated charges, preventing the photodiodes from becoming saturated due to the charges generated in the photodiodes.

[0009] The various yet significant advantages and effects of the present invention are not limited to the above, but can be more easily understood in the course of describing specific embodiments of the present invention. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a simplified block diagram of an image sensor according to an embodiment of the present invention; [Figure 2] 1 is a circuit diagram illustrating a pixel circuit of an image sensor according to an embodiment of the present invention. [Figure 3] FIG. 1 is a plan view showing a simplified pixel array included in a general image sensor. [Figure 4]FIG. 1 is a plan view showing a simplified pixel array included in a general image sensor. [Figure 5] 1 is a plan view illustrating a pixel group included in an image sensor according to an embodiment of the present invention; [Figure 6] 2 is a plan view illustrating a first pixel group included in an image sensor according to an embodiment of the present invention. FIG. [Figure 7] 3 is a cross-sectional view illustrating a first pixel group included in an image sensor according to an embodiment of the present invention. [Figure 8] 3 is a cross-sectional view illustrating a first pixel group included in an image sensor according to an embodiment of the present invention. [Figure 9] 3 is a cross-sectional view illustrating a first pixel group included in an image sensor according to an embodiment of the present invention. [Figure 10] 4 is a plan view illustrating a second pixel group included in an image sensor according to an embodiment of the present invention. FIG. [Figure 11] 4 is a cross-sectional view illustrating a second pixel group included in an image sensor according to an embodiment of the present invention. [Figure 12] 4 is a cross-sectional view illustrating a second pixel group included in an image sensor according to an embodiment of the present invention. [Figure 13] 4 is a cross-sectional view illustrating a second pixel group included in an image sensor according to an embodiment of the present invention. [Figure 14a] 2A to 2C are diagrams illustrating a manufacturing process of an image sensor according to an embodiment of the present invention; [Figure 14b] 2A to 2C are diagrams illustrating a manufacturing process of an image sensor according to an embodiment of the present invention; [Figure 15a] 2A to 2C are diagrams illustrating a manufacturing process of an image sensor according to an embodiment of the present invention; [Figure 15b] 2A to 2C are diagrams illustrating a manufacturing process of an image sensor according to an embodiment of the present invention; [Figure 16a] 2A to 2C are diagrams illustrating a manufacturing process of an image sensor according to an embodiment of the present invention; [Figure 16b] 1 is a diagram illustrating a manufacturing process of an image sensor according to an embodiment of the present invention; [Figure 17] 2A to 2C are diagrams illustrating a manufacturing process of an image sensor according to an embodiment of the present invention; [Figure 18] 10 is a plan view illustrating a pixel group included in an image sensor according to another embodiment of the present invention; FIG. [Figure 19] 10 is a plan view illustrating a pixel group included in an image sensor according to another embodiment of the present invention; FIG. [Figure 20] 10 is a plan view illustrating a pixel group included in an image sensor according to another embodiment of the present invention; FIG. [Figure 21] 1 is a plan view showing a simplified pixel array included in an image sensor according to various embodiments of the present invention; [Figure 22] 1 is a plan view showing a simplified pixel array included in an image sensor according to various embodiments of the present invention; [Figure 23] 1 is a plan view showing a simplified pixel array included in an image sensor according to various embodiments of the present invention; [Figure 24] 1 is a plan view showing a simplified pixel array included in an image sensor according to various embodiments of the present invention; [Figure 25] 1 is a simplified diagram of an electronic device including an image sensor according to an embodiment of the present invention; [Figure 26] 1 is a simplified diagram of an electronic device including an image sensor according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, specific examples of embodiments of the present invention will be described in detail with reference to the drawings.

[0012] FIG. 1 is a simplified block diagram of an image sensor according to one embodiment of the present invention.

[0013] Referring to FIG. 1, an image sensor 1 according to the present embodiment includes a pixel array 10 and a logic circuit 20.

[0014] The pixel array 10 includes a plurality of unit pixels PX arranged in an array along a plurality of rows and a plurality of columns. Each unit pixel PX includes at least one photoelectric conversion element that generates charges in response to light, a pixel circuit that generates a pixel signal corresponding to the charges generated by the photoelectric conversion element, and the like.

[0015] The photoelectric conversion element may be a photodiode made of a semiconductor material, an organic photodiode made of an organic material, etc. In one embodiment, each unit pixel PX includes two or more photoelectric conversion elements, and the two or more photoelectric conversion elements included in one unit pixel PX receive light of different colors and generate charges. In this embodiment, each of the plurality of unit pixels PX includes a photodiode that receives light and generates charges. However, this is merely an example and is not limiting.

[0016] According to an embodiment, the pixel circuit includes a transfer transistor, a drive transistor, a selection transistor, a reset transistor, etc. When each unit pixel PX has one photoelectric conversion element, each unit pixel PX includes a pixel circuit for processing charges generated from the photoelectric conversion element. As an example, each of the unit pixels PX included in the image sensor 1 according to this embodiment includes a photodiode. Thus, the pixel circuit corresponding to each unit pixel PX includes a transfer transistor, a drive transistor, a selection transistor, and a reset transistor.

[0017] However, this is merely one embodiment and is not limiting. As an example, a plurality of unit pixels PX included in the image sensor 1 according to this embodiment share a floating diffusion region in units of subpixel groups, so that at least some of the photoelectric conversion elements share parts of the drive transistor, the select transistor, and the reset transistor.

[0018] The logic circuit 20 includes circuits for controlling the pixel array 10. As an example, the logic circuit 20 includes a row driver 21, a readout circuit 22, a column driver 23, and control logic 24.

[0019] The row driver 21 drives the pixel array 10 row by row. For example, the row driver 21 generates a transfer control signal that controls a transfer transistor of a pixel circuit, a reset control signal that controls a reset transistor, a selection control signal that controls a selection transistor, and the like, and inputs these signals to the pixel array 10 row by row.

[0020] The readout circuit 22 includes a correlated double sampler (CDS), an analog-to-digital converter (ADC), etc. The correlated double sampler is connected to the unit pixel PX via a column line. The correlated double sampler performs correlated double sampling by receiving a pixel signal from the unit pixel PX connected to a row line selected by a row line selection signal of the row driver 21. The pixel signal is received via the column line. The analog-to-digital converter converts the pixel signal detected by the correlated double sampler into a digital pixel signal and transmits it to the column driver 23.

[0021] The column driver 23 includes a latch or buffer circuit that temporarily stores the digital pixel signal and an amplifier circuit, and processes the digital pixel signal received from the readout circuit 22. The row driver 21, the readout circuit 22, and the column driver 23 are controlled by a control logic 24. The control logic 24 includes a timing controller for controlling the operation timing of the row driver 21, the readout circuit 22, and the column driver 23.

[0022] Among the unit pixels PX, unit pixels PX arranged at the same horizontal position share the same column line. For example, unit pixels PX arranged at the same vertical position are simultaneously selected by the row driver 21 and output pixel signals via the column lines. In one embodiment, the readout circuit 22 simultaneously acquires pixel signals from the unit pixels PX selected by the row driver 21 via the column lines. The pixel signals include a reset voltage and a pixel voltage, and the pixel voltage is a voltage obtained by reflecting charges generated in each unit pixel PX in response to light on the reset voltage. However, the content described above with reference to FIG. 1 is not limited thereto, and the image sensor may further include other configurations and be driven in various ways.

[0023] FIG. 2 is a circuit diagram showing a pixel circuit of an image sensor according to an embodiment of the present invention.

[0024] A plurality of unit pixels PX included in the image sensor 1 according to this embodiment are grouped into sub-pixel groups. As an example, one sub-pixel group includes four unit pixels PX.

[0025] Referring to FIG. 2, in the image sensor 1 according to this embodiment, the pixel circuits PXC corresponding to each of the plurality of sub-pixel groups include photodiodes (PD1, PD2, PD3, PD4) corresponding to the plurality of unit pixels PX, as well as a plurality of semiconductor elements for processing the charges generated from the photodiodes (PD1, PD2, PD3, PD4).

[0026] For example, the pixel circuit PXC includes first to fourth photodiodes (PD1 to PD4), first to fourth transfer transistors (TX1 to TX4), a reset transistor RX, a selection transistor SX, and a drive transistor DX. The first to fourth photodiodes (PD1 to PD4) included in the pixel circuit PXC share a floating diffusion region FD, a reset transistor RX, a selection transistor SX, and a drive transistor DX. The gate electrodes of the first to fourth transfer transistors (TX1 to TX4), the reset transistor RX, and the selection transistor SX are connected to drive signal lines (TG1 to TG4, RG, SG), respectively. However, this is merely an example and is not limited to the example shown in FIG. 2 , and the pixel circuit PXC may be designed in various ways.

[0027] In this embodiment, one of the pixel circuits PXC generates a first electrical signal from charges generated in the photodiodes (PD1 to PD4) included in the pixel circuit PXC and outputs it to a first column line, and another pixel circuit generates a second electrical signal from charges generated in the photodiodes (PD1 to PD4) included in the pixel circuit PXC and outputs it to a second column line. According to one embodiment, two or more pixel circuits arranged adjacent to each other share one first column line. Similarly, two or more other pixel circuits arranged adjacent to each other share one second column line. The pixel circuits arranged adjacent to each other share some semiconductor elements.

[0028] The first to fourth transfer transistors (TX1 to TX4) are respectively connected to the first to fourth transfer gates (TG1 to TG4) and the first to fourth photodiodes (PD1 to PD4). Meanwhile, the first to fourth transfer transistors (TX1 to TX4) share a floating diffusion region FD. The first to fourth photodiodes (PD1 to PD4) generate charges in proportion to the amount of light incident from the outside and accumulate the charges in each photodiode.

[0029] The first to fourth transfer transistors (TX1 to TX4) sequentially transfer the charges accumulated in the first to fourth photodiodes (PD1 to PD4) to the floating diffusion region FD. Different signals are applied to the first to fourth transfer gates (TG1 to TG4) to transfer the charges generated from any of the first to fourth photodiodes (PD1 to PD4) to the floating diffusion region FD. As a result, the floating diffusion region FD accumulates the charges generated from any of the first to fourth photodiodes (PD1 to PD4).

[0030] The reset transistor RX periodically resets the charge stored in the floating diffusion region FD. As an example, the electrode of the reset transistor RX is connected to the floating diffusion region FD and the power supply voltage V DD When the reset transistor RX is turned on, the power supply voltage V DD The charge stored in the floating diffusion region FD is discharged due to the potential difference between the power supply voltage V and the floating diffusion region FD is reset. DD becomes identical to

[0031] The operation of the drive transistor DX is controlled according to the amount of charge accumulated in the floating diffusion region FD. The drive transistor DX acts as a source follower buffer amplifier in combination with a current source located outside the unit pixel PX. For example, it amplifies the potential change caused by the charge accumulation in the floating diffusion region FD and outputs it to the output line (Vout).

[0032] The selection transistor SX selects a unit pixel PX to be read in a row unit. When the selection transistor SX is turned on, an electrical signal output from the driving transistor DX is transferred to the selection transistor SX.

[0033] The image sensor 1 according to this embodiment can provide an autofocus function in at least one of a plurality of subpixel groups including a plurality of unit pixels sharing a floating diffusion region FD based on the pixel circuit PXC shown in Fig. 2. As an example, the image sensor 1 provides the autofocus function in four directions (e.g., up / down and left / right) using the first to fourth photodiodes PD1 to PD4.

[0034] For example, the logic circuit provides an autofocus function in the horizontal direction using a first pixel signal obtained after the first transfer transistor TX1 is turned on and a second pixel signal obtained after the second transfer transistor TX2 is turned on. Meanwhile, the logic circuit provides an autofocus function in the vertical direction using a first pixel signal obtained after the first transfer transistor TX1 is turned on and a third pixel signal obtained after the third transfer transistor TX3 is turned on. However, the pixel circuit of the unit pixel providing the autofocus function is not necessarily limited to that shown in FIG. 2, and some elements may be added or omitted as necessary.

[0035] 3 and 4 are plan views showing a simplified pixel array included in a general image sensor.

[0036] 3 and 4, a pixel array included in a typical image sensor includes a plurality of unit pixels PX. For example, the plurality of unit pixels PX are arranged in a 2×2 array to form sub-pixel groups SPG. Meanwhile, the plurality of sub-pixel groups SPG are arranged in a 2×2 array to form pixel groups PG. For example, a color filter of the same color is disposed for each pixel group PG. That is, the pixel array includes a plurality of pixel groups PG corresponding to the color filters, and each of the plurality of pixel groups PG includes a plurality of unit pixels PX arranged in a 4×4 format.

[0037] The color filters disposed on the plurality of pixel groups PG have any one of red (R), green (G), and blue (B). For example, the pixel array of the image sensor includes a color filter having a color filter array CFA in which green, red, blue, and green are repeatedly arranged in this order to correspond to the plurality of pixel groups PG arranged in a 2x2 format. However, this is merely one embodiment, and the repeated color filter array CFA may be different. For example, the color filter array CFA may also include a white color filter.

[0038] In a typical image sensor, each of a plurality of unit pixels PX included in a pixel array includes a photodiode, and a microlens on top of the unit pixel PX through which light is incident to generate an electrical signal from the photodiode.

[0039] 3, in the pixel array of the image sensor, a microlens is arranged to correspond to each of a plurality of sub-pixel groups SPG. For example, a plurality of unit pixels PX arranged in a 2x2 configuration share one microlens.

[0040] A plurality of unit pixels PX sharing one microlens may function as an autofocus pixel. For example, a plurality of photodiodes included in each of the plurality of unit pixels PX are arranged along a second direction (e.g., X direction) perpendicular to a first direction (e.g., Z direction) in which the microlenses are arranged, and a third direction (e.g., Y direction) perpendicular to the first and second directions. The image sensor performs an autofocus function in the second direction using pixel signals acquired from two unit pixels PX arranged side by side in the second direction, and performs an autofocus function in the third direction using pixel signals acquired from two unit pixels PX arranged side by side in the third direction. As a result, the image sensor including the pixel array shown in FIG. 3 can perform an autofocus function in four directions.

[0041] However, since a plurality of unit pixels PX included in one sub-pixel group SPG share a single microlens, light incident on one microlens is divided and incident on four unit pixels PX. For example, light incident through one microlens is affected by reflection and refraction. Therefore, compared to an image sensor in which each of a plurality of unit pixels PX includes a microlens, an image sensor having the pixel array shown in FIG. 3 may perform remosaic, which involves complex correction and high power consumption, and may generate an image with relatively low resolution.

[0042] 4, in the pixel array of the image sensor, microlenses are arranged to correspond to each of a plurality of unit pixels PX. For example, one subpixel group SPG includes microlenses arranged in a 2x2 pattern.

[0043] The image sensor including the pixel array shown in Figure 4 can generate images with relatively high resolution because it does not require re-mosaic during the image generation process. However, light incident between the microlenses may be reflected, resulting in optical loss during image generation by the image sensor. In addition, the image sensor has a problem in that it cannot perform an autofocus function because the photodiodes and microlenses are configured to correspond to each other.

[0044] FIG. 5 is a plan view illustrating a pixel group included in an image sensor according to an embodiment of the present invention.

[0045] 5 is a diagram showing pixel groups (PG1, PG2) and their configurations corresponding to one color filter array included in the image sensor 100 according to this embodiment. As an example, one color filter array corresponds to four pixel groups (PG1, PG2), and each pixel group (PG1, PG2) in a first direction (e.g., Z direction) includes a color filter having a predetermined color.

[0046] 5, in the image sensor 100 according to this embodiment, each pixel group (PG1, PG2) includes a plurality of unit pixels PX arranged in a 4x4 pattern. Meanwhile, the pixel group (PG1, PG2) includes a first pixel group PG1 and a second pixel group PG2. The first pixel group PG1 and the second pixel group PG2 are alternately arranged in a second direction (e.g., X direction) perpendicular to the first direction and a third direction (e.g., Y direction) perpendicular to the first and second directions.

[0047] Meanwhile, according to the embodiment shown in FIG. 5, the plurality of first pixel groups PG1 include green color filters, and the plurality of second pixel groups PG2 include red or blue color filters.

[0048] A plurality of unit pixels PX included in each pixel group (PG1, PG2) are defined by device isolation films DTI disposed therebetween, and each of the plurality of unit pixels PX separated by the device isolation films DTI includes a photodiode PD. Each pixel group (PG1, PG2) includes a microlens ML disposed on top of a color filter. The microlens ML includes a first microlens ML1 and a second microlens ML2. The first microlens ML1 and the second microlens ML2 are disposed at the top of the plurality of unit pixels PX in a first direction and allow external light to enter.

[0049] For example, the first pixel group PG1 includes a first microlens ML1 corresponding to each of the plurality of unit pixels PX, and the second pixel group PG2 includes a second microlens ML2 shared by the plurality of unit pixels PX arranged in a 2x2 pattern. For example, the first microlens ML1 has a first diameter, and the second microlens ML2 has a second diameter larger than the first diameter. For example, the second diameter is twice the first diameter. However, this is merely an example and is not limiting. For example, as long as the first microlens ML1 corresponds to the plurality of unit pixels PX and the second microlens ML2 corresponds to the subpixel group, the diameters and shapes of the first microlens ML1 and the second microlens ML2 may vary depending on the embodiment.

[0050] Since the first microlens ML1 corresponds to one unit pixel PX, the unit pixels PX included in the first pixel group PG1 cannot operate as autofocus pixels. However, an image generated using pixel signals acquired from the unit pixels PX included in the first pixel group PG1 does not require a separate re-mosaic process and therefore has a relatively high resolution.

[0051] Meanwhile, since the second microlenses ML2 correspond to the unit pixels PX arranged in a 2x2 pattern, the unit pixels PX included in the second pixel group PG2 can operate as autofocus pixels. For example, pixel signals acquired from the unit pixels PX sharing the second microlenses ML2 include autofocus pixel signals. The unit pixels PX included in the second pixel group PG2 can perform autofocus functions in four directions, i.e., up, down, left, and right. In addition, the image sensor 100 can reduce optical loss by using structural features of the second microlenses ML2 included in the second pixel group PG2.

[0052] The image sensor 100 according to this embodiment uses both the first microlens ML1 and the second microlens ML2 having different diameters, thereby reducing the correction and power consumption required when generating an image, and generating an image with a relatively high resolution and an autofocus function.

[0053] FIG. 6 is a plan view illustrating a first pixel group included in an image sensor according to an embodiment of the present invention.

[0054] 6, in the image sensor 100 according to this embodiment, the first pixel group PG1 includes a plurality of unit pixels PX that share a floating diffusion region FD and a plurality of first sub-pixel groups SPG1 that are arranged in a 2×2 configuration. For example, each of the plurality of first sub-pixel groups SPG1 includes a plurality of unit pixels PX that are arranged in a 2×2 configuration.

[0055] The first pixel group PG1 includes a color filter having a predetermined color. For example, the color filter included in the first pixel group PG1 is green. However, this is merely an example and is not limiting. The color of the color filter may vary depending on the embodiment.

[0056] Each of the unit pixels PX includes a photodiode PD that receives external light and generates an electrical signal. Each of the unit pixels PX includes a first microlens ML1 corresponding to each of the unit pixels PX. For example, the center of the first microlens ML1 overlaps the photodiode PD in a first direction (e.g., the Z direction).

[0057] The plurality of unit pixels PX are defined by isolation layers DTI extending in a first direction. Meanwhile, the isolation layers DTI are separated from each other in a second direction (e.g., X direction) perpendicular to the first direction and a third direction (e.g., Y direction) perpendicular to the first and second directions in a region adjacent to the floating diffusion region FD. For example, one region where the isolation layers DTI are separated from each other is formed for each first sub-pixel group SPG1.

[0058] The device isolation layer DTI accumulates charges generated from the photodiode PD included in each of the plurality of unit pixels PX in the corresponding photodiode PD. In the image sensor 100 according to the present embodiment, the device isolation layer DTI defining the plurality of unit pixels PX included in the first pixel group PG1 is formed so that charges generated from the photodiode PD included in each of the plurality of unit pixels PX do not overflow to the photodiode PD included in another pixel.

[0059] That is, in the first pixel group PG1 of the image sensor 100 according to this embodiment, the floating diffusion region FD included in the first sub-pixel group SPG1 is shared among the plurality of unit pixels PX included in the first sub-pixel group SPG1, while the device isolation layer DTI is separated to such an extent that overflow does not occur among the plurality of unit pixels PX sharing the floating diffusion region FD.

[0060] 7 to 9 are cross-sectional views illustrating a first pixel group included in an image sensor according to an embodiment of the present invention.

[0061] Figures 7 to 9 are cross-sectional views of image sensor 100 shown in Figure 6 taken along lines II-II' to IV-IV', respectively. As an example, Figure 7 is a cross-sectional view showing a cross section taken along line II-II' in Figure 6, Figure 8 is a cross-sectional view showing a cross section taken along line III-III' in Figure 6, and Figure 9 is a cross-sectional view showing a cross section taken along line IV-IV' in Figure 6.

[0062] 7 to 9, the image sensor 100 according to the present embodiment includes a substrate 110 having a first surface 111 and a second surface 112 facing each other, and an isolation layer DTI disposed between a plurality of unit pixels PX within the substrate 110. For example, the plurality of unit pixels PX are arranged in a direction parallel to the first surface 111. Meanwhile, each of the plurality of unit pixels PX includes a photodiode PD disposed within the substrate 110.

[0063] In the first pixel group PG1 included in the image sensor 100 according to this embodiment, a color filter 120, a light-transmitting layer 130, and a first microlens ML1 are sequentially disposed on the first surface 111 of the substrate 110. As an example, in the first pixel group PG1, the color filter 120 is green, and the first microlens ML1 corresponds to each of the plurality of unit pixels PX. However, this is merely an example and is not limiting.

[0064] The light incident through the first microlens ML1 is incident on the photodiode included in each of the plurality of unit pixels PX. As described above, the first pixel group PG1 of the image sensor 100 according to this embodiment can improve the resolution of the generated image by using the plurality of unit pixels PX that share the floating diffusion region FD and the first microlens ML1 corresponding to each of the plurality of unit pixels PX.

[0065] In the image sensor 100 according to this embodiment, a pixel circuit is disposed below the photodiode PD. For example, the pixel circuit includes a plurality of elements 160, a wiring pattern 170 connected to the plurality of elements 160, and an insulating layer 180 covering the plurality of elements 160 and the wiring pattern 170, and is disposed on the second surface 112 of the substrate 110. The pixel circuit operates to acquire pixel signals from a plurality of unit pixels PX.

[0066] The pixel circuit includes a floating diffusion region FD. For example, a plurality of unit pixels PX included in the first sub-pixel group share a floating diffusion region FD disposed between the plurality of unit pixels PX. However, the floating diffusion region FD is not limited to that shown in FIGS. 8 and 9. For example, the position and area of ​​the floating diffusion region FD may be variously modified depending on the embodiment.

[0067] The elements 160 adjacent to the floating diffusion region FD are first to fourth transfer transistors. The gates of the first to fourth transfer transistors each have a vertical structure in which at least a portion of the gate is buried in the substrate 110.

[0068] A plurality of unit pixels PX included in a first pixel group PG1 of the image sensor 100 according to this embodiment are isolated from one another by device isolation films DTI as shown in Fig. 7. Meanwhile, the device isolation films DTI are isolated from one another in a second direction and a third direction as shown in Figs. 8 and 9, and floating diffusion regions FD are disposed in the regions isolated by the device isolation films DTI. Meanwhile, the device isolation films DTI are isolated to such an extent that charge overflow does not occur between adjacent photodiodes.

[0069] FIG. 10 is a plan view illustrating a second pixel group included in an image sensor according to an embodiment of the present invention.

[0070] 10, in the image sensor 100 according to this embodiment, the second pixel group PG2 includes a plurality of unit pixels PX that share a floating diffusion region FD and a plurality of second sub-pixel groups SPG2 that are arranged in a 2 x 2 configuration. For example, each of the plurality of second sub-pixel groups SPG2 includes a plurality of unit pixels PX that are arranged in a 2 x 2 configuration.

[0071] The second pixel group PG2 includes a color filter having a predetermined color. For example, the color filter included in the second pixel group PG2 may be red or blue. However, this is merely an example and is not limiting. The color of the color filter may vary depending on the embodiment.

[0072] Each of the plurality of unit pixels PX includes a photodiode PD that receives external light and generates an electrical signal. The second subpixel group SPG2 includes a second microlens ML2 shared by the plurality of unit pixels PX included in the second subpixel group SPG2. For example, the center of the second microlens ML2 overlaps with the floating diffusion region FD in the first direction (e.g., the Z direction).

[0073] Since the second microlens ML2 is shared by a plurality of unit pixels PX arranged in a 2×2 pattern included in one second sub-pixel group SPG2, the plurality of unit pixels PX included in the second pixel group PG2 may include an autofocus pixel. The plurality of unit pixels PX can perform an autofocus function in a second direction (e.g., X direction) perpendicular to the first direction and a third direction (e.g., Y direction) perpendicular to the first and second directions. For example, the unit pixels PX arranged in the second direction perform the autofocus function using a phase difference between the left and right of incident light, and the unit pixels PX arranged in the third direction perform the autofocus function using a phase difference between the up and down of incident light.

[0074] Similar to the first pixel group PG1 shown in FIG. 6, the plurality of unit pixels PX are defined by isolation layers DTI extending in a first direction. Meanwhile, the isolation layers DTI are separated from each other in a region adjacent to the floating diffusion region FD. For example, one region where the isolation layers DTI are separated from each other is formed for each second sub-pixel group SPG2. However, the length in the second and / or third direction of the region where the isolation layers DTI are separated in the second pixel group PG2 is greater than the length in the second and / or third direction of the region where the isolation layers DTI are separated in the first pixel group PG1.

[0075] The device isolation film DTI accumulates charges generated from the photodiode PD included in each of the plurality of unit pixels PX in the corresponding photodiode PD. In the image sensor 100 according to the present embodiment, the device isolation film DTI defining the plurality of unit pixels PX included in the second pixel group PG2 includes an overflow region OF that allows generated charges to overflow to the photodiode PD included in another adjacent pixel when the photodiode PD included in each of the plurality of unit pixels PX is saturated.

[0076] That is, in the second pixel group PG2 of the image sensor 100 according to this embodiment, the floating diffusion region FD included in the second sub-pixel group SPG2 is shared among a plurality of unit pixels PX included in the second sub-pixel group SPG2, and the device isolation layer DTI is separated among the plurality of unit pixels PX sharing the floating diffusion region FD to form an overflow region OF.

[0077] In the image sensor 100 according to this embodiment, the overflow region OF included in the second pixel group PG2 can prevent saturation of the photodiode PD due to charges generated in excess of the capacitance of each of the unit pixels PX. Therefore, the maximum amount of charges generated and accumulated in each of the unit pixels PX included in the second pixel group PG2 is greater than the maximum amount of charges generated and accumulated in each of the unit pixels PX included in the first pixel group PG1.

[0078] 11 to 13 are cross-sectional views illustrating a second pixel group included in an image sensor according to an embodiment of the present invention.

[0079] Figures 11 to 13 are cross-sectional views of image sensor 100 shown in Figure 10 taken along lines V-V' to VII-VII', respectively. As an example, Figure 11 is a cross-sectional view showing a cross section taken along line V-V' in Figure 10, Figure 12 is a cross-sectional view showing a cross section taken along line VI-VI' in Figure 10, and Figure 13 is a cross-sectional view showing a cross section taken along line VII-VII' in Figure 10.

[0080] Figures 11 to 13 correspond to Figures 7 to 9, respectively. As an example, the configuration of the image sensor 100 shown in Figures 11 to 13 corresponds to the configuration of the image sensor 100 shown in Figures 7 to 9. However, the second pixel group PG2 shown in Figures 11 to 13 differs from the first pixel group PG1 shown in Figures 7 to 9 in relation to the second microlens ML2, the color of the color filter 120, the shape of the element isolation film DTI, and the overflow region OF.

[0081] In the second pixel group PG2 included in the image sensor 100 according to this embodiment, a color filter 120, a light-transmitting layer 130, and a second microlens ML2 are sequentially disposed on the first surface 111 of the substrate 110. As an example, in the second pixel group PG2, the color filter 120 is red or blue, and the second microlens ML2 is shared by a plurality of unit pixels PX included in the second sub-pixel group SPG2. However, this is merely an example and is not limiting.

[0082] The light incident through the second microlens ML2 is incident on the photodiodes of the unit pixels PX included in the second sub-pixel group SPG2 corresponding to the second microlens ML2. As described above, the second pixel group PG2 of the image sensor 100 according to this embodiment reduces optical loss during image generation by using the unit pixels PX that share the floating diffusion region FD and the second microlens ML2 shared by the unit pixels PX, and can perform an autofocus function in four directions.

[0083] A plurality of unit pixels PX included in the second pixel group PG2 of the image sensor 100 according to this embodiment are isolated from one another by a device isolation film DTI as shown in FIG. 10. Meanwhile, the device isolation film DTI is isolated from one another in a second direction and a third direction as shown in FIGS. 12 and 13, and a floating diffusion region FD is disposed in the region where the device isolation film DTI is isolated. An overflow region OF is formed in the region where the device isolation film DTI is isolated, i.e., between the floating diffusion region FD and the device isolation film DTI. Before any photodiode PD is saturated, charges generated from the corresponding photodiode PD are transferred to an adjacent photodiode via the overflow region OF.

[0084] A manufacturing process of an image sensor according to an embodiment of the present invention will now be described.

[0085] Figures 14a to 17 are views showing a process for manufacturing the image sensor 100 according to an embodiment of the present invention shown in Figures 5 to 13. Meanwhile, Figures 14a, 15a, 16a, and 17 are cross-sectional views showing a cross section along line II' in Figure 6, and Figures 14b, 15b, and 16b are top views of the image sensor 100 during the process.

[0086] Referring to Figures 14a and 14b, the process for manufacturing the image sensor 100 according to this embodiment includes, before forming an isolation layer, forming a trench H in the substrate 110 to extend in a first direction and separate pixel regions in which a plurality of unit pixels PX are formed.

[0087] In the image sensor 100 according to this embodiment, a mask layer 115 is formed on one upper surface of the substrate 110 before forming the trench H. For example, the mask layer 115 is a layer for protecting the substrate 110 so that areas other than the area where the trench H is to be formed are not etched during an etching process for forming the trench H.

[0088] The trench H is formed by an etching process following the formation of the mask layer 115. However, the shape of the trench H is not limited to that shown in FIGS. 14a and 14b, and may be variously modified depending on the embodiment.

[0089] The isolation layer included in the image sensor 100 according to this embodiment is formed by a front deep trench isolation (FDTI) process. Thus, a trench H for forming the isolation layer is formed from the second surface of the substrate 110, where the pixel circuit is disposed, to the first surface of the substrate 110, where the microlens is disposed. However, this is merely an example and is not limiting.

[0090] In the image sensor 100 according to this embodiment, the isolation layers formed in the first pixel group and the second pixel group are different from each other. For example, the isolation layers are separated from each other in the region where the floating diffusion regions are formed. Therefore, the trenches H formed by an etching process to form the isolation layers do not completely penetrate the substrate 110, and the depths of the trenches H in the region where the first pixel group is formed and the region where the second pixel group is formed in the second direction (e.g., X direction) and the third direction (e.g., Y direction) are different.

[0091] 14b, trenches H for forming isolation layers in the region where the first pixel group is formed are separated by a length D1 in the second and third directions. Meanwhile, trenches H for forming isolation layers in the region where the second pixel group is formed are separated by a length D2 in the second and third directions. For example, D1 is smaller than D2. The cross section along the illustrated line I-I' passes through trenches H in the region where the first pixel group is formed, but does not pass through trenches H in the region where the second pixel group is formed.

[0092] 15a and 15b, a process for manufacturing the image sensor 100 according to this embodiment includes forming a device isolation layer DTI by implanting impurities into the substrate 110 through the trench H. As an example, the impurities implanted into the substrate 110 through the trench H are diffused to form a photodiode PD.

[0093] Meanwhile, since the depths of the trenches H formed in the region where the first pixel group is formed and the region where the second pixel group is formed differ in the second and third directions, the shape of the isolation film DTI formed inside the trenches H also differs. As an example, in the region where the second pixel group is formed, an overflow region OF through which charges move is formed between the photodiodes PD.

[0094] 16a and 16b, a process for manufacturing an image sensor 100 according to this embodiment includes forming a second surface 112 of a substrate 110 and disposing a pixel circuit on the second surface 112. As described above, the pixel circuit includes a plurality of elements, a wiring pattern connected to the plurality of elements, an insulating layer covering the plurality of elements and the wiring pattern, etc. As an example, the plurality of elements includes a floating diffusion region FD.

[0095] After forming the isolation film DTI, the mask layer 115, a portion of the substrate 110, and a portion of the isolation film DTI that were formed for the previous process are removed by a polishing process or the like. The upper surface of the substrate 110 that has been removed by the polishing process or the like is the second surface 112. For example, a pixel circuit is disposed on the second surface 112 of the substrate 110.

[0096] 17, a process for manufacturing an image sensor 100 according to this embodiment includes removing a portion of a substrate 110 from the opposite side of a pixel circuit by a polishing process. For example, the portion removed by the polishing process includes a portion of a device isolation layer DTI, and the remaining surface of the substrate 110 is a first surface 111.

[0097] Meanwhile, the image sensor 100 according to this embodiment includes a color filter 120, a light-transmitting layer 130, and first and second microlenses ML1 and ML2, which are sequentially arranged on a first surface 111. This allows the image sensor 100 shown in FIGS. 5 and 17 to be manufactured. However, this is merely one embodiment, and the structure of the manufactured image sensor 100 is not limited to that shown in FIG. 17.

[0098] 18 to 20 are plan views illustrating pixel groups included in an image sensor according to another embodiment of the present invention.

[0099] 18 is a diagram showing pixel groups (PG1, PG2) and their configuration corresponding to one color filter array included in the image sensor 200 according to this embodiment. As an example, similar to the image sensor 100 shown in FIG. 5, one color filter array corresponds to four pixel groups (PG1, PG2), and each pixel group (PG1, PG2) in a first direction (e.g., Z direction) includes a color filter having a predetermined color.

[0100] 18, one color filter array includes color filters arranged in the order of green, red, blue, and green as shown in Fig. 5. The pixel groups (PG1, PG2) include a plurality of first pixel groups PG1 including first microlenses ML1 corresponding to each of the plurality of unit pixels PX, and a plurality of second pixel groups PG2 including second microlenses ML2 shared by the plurality of unit pixels PX arranged in a 2x2 configuration.

[0101] However, unlike the image sensor 100 shown in Fig. 5, the image sensor 200 shown in Fig. 18 has a plurality of first pixel groups PG1 including red or blue color filters and a plurality of second pixel groups PG2 including green color filters. For example, the arrangement of other components included in the image sensor 200 is the same as that of the image sensor 100 shown in Fig. 5.

[0102] 19 and 20 are diagrams illustrating the second pixel group PG2 and the first pixel group PG1 of the image sensor 200 according to this embodiment. As an example, FIGS. 19 and 20 correspond to FIGS. 10 and 6, respectively. However, the image sensor 200 shown in FIGS. 19 and 20 differs from the image sensor 100 shown in FIGS. 10 and 6 in the colors of the color filters.

[0103] Humans can recognize the brightness, intensity, and color of light that enters their eyes. Generally, humans are most sensitive to the brightness, intensity, and color of green light that enters their eyes. Therefore, the image sensor 100 shown in FIG. 5, which generates an image with high resolution in the unit pixel PX corresponding to the green color filter and performs an autofocus function in the unit pixel PX corresponding to the red or blue color filter, corresponds to an embodiment that is closer to the human eye. However, this is merely one embodiment and is not limited thereto. Images can also be generated using the image sensor 200 shown in FIG. 18, if necessary.

[0104] 21 to 24 are plan views each showing a pixel array included in an image sensor according to various embodiments of the present invention.

[0105] 21 to 24 are diagrams showing pixel arrays included in image sensors according to other embodiments, along with the image sensors (100, 200) shown in FIGS. 5 and 18. In FIG.

[0106] In the pixel arrays (100A, 200A, 300A, 400A) included in the image sensor according to this embodiment, a plurality of unit pixels PX are arranged in a 2×2 pattern to form sub-pixel groups (SPG1, SPG2). Meanwhile, a plurality of sub-pixel groups (SPG1, SPG2) arranged in a 2×2 pattern form pixel groups (PG1, PG2).

[0107] The color filters included in the plurality of pixel groups (PG1, PG2) have any one of red R, green G, and blue B. As an example, the pixel arrays (100A, 200A, 300A, 400A) of the image sensor include color filters having a color filter array CFA in which green, red, blue, and green are arranged repeatedly in this order to correspond to the plurality of pixel groups (PG1, PG2) arranged in a 2×2 format.

[0108] That is, in the pixel arrays (100A, 200A, 300A, 400A), color filters of the same color are arranged for each pixel group (PG1, PG2), and each of the pixel groups (PG1, PG2) includes a plurality of unit pixels PX arranged in a 4x4 format.

[0109] The plurality of pixel groups (PG1, PG2) are classified as a first pixel group PG1 or a second pixel group PG2. The first pixel group PG1 includes a first sub-pixel group SPG1 and a first microlens ML1 disposed on the substrate. Meanwhile, the second pixel group PG2 includes a second sub-pixel group SPG2 and a second microlens ML2 disposed on the substrate. As an example, each of the plurality of pixel groups (PG1, PG2) includes only one of the first sub-pixel group SPG1 or the second sub-pixel group SPG2.

[0110] As an example, the pixel array 100A shown in FIG. 21 is the pixel array 100A included in the image sensor 100 shown in FIG. 5, and the pixel array 200A shown in FIG. 22 is the pixel array 200A shown in FIG.

[0111] Referring to the pixel array 300A according to an embodiment shown in FIG. 23, the first pixel group (PG1a, PG1b) includes a color filter having any one of green, red, and blue colors.

[0112] For example, the second pixel group PG2 includes a red or blue color filter, while at least one first pixel group PG1a includes a green color filter, but at least another first pixel group PG1b includes a red or blue color filter.

[0113] As described above, the first pixel group (PG1a, PG1b) includes the first sub-pixel group (SPG1a, SPG1b) and includes the first microlens ML1 disposed on the substrate. Meanwhile, the second pixel group PG2 includes the second sub-pixel group SPG2 and includes the second microlens ML2 disposed on the substrate. Therefore, the image sensor including the pixel array 300A according to this embodiment can generate images with higher resolution compared to the image sensor 100 shown in FIG. 5, but the autofocus performance is reduced.

[0114] Referring to the pixel array 400A according to one embodiment shown in FIG. 24, the second pixel group (PG2a, PG2b) includes a color filter having any one of green, red, and blue colors.

[0115] For example, the first pixel group PG1 includes a green color filter, while at least one second pixel group PG2a includes a red or blue color filter, but at least another second pixel group PG2b includes a green color filter.

[0116] As described above, the first pixel group (PG1a, PG1b) includes the first sub-pixel group (SPG1a, SPG1b) and includes the first microlens ML1 disposed on the substrate. Meanwhile, the second pixel group PG2 includes the second sub-pixel group SPG2 and includes the second microlens ML2 disposed on the substrate. Therefore, the image sensor including the pixel array 400A according to this embodiment has improved autofocus performance but reduced resolution of the generated image compared to the image sensor 100 shown in FIG.

[0117] However, the shape of the pixel array included in the image sensor according to this embodiment is not limited to those shown in Figures 21 to 24. As an example, the image sensor generates an image having a resolution appropriate for appropriate autofocus performance as needed.

[0118] 25 and 26 are simplified diagrams of an electronic device including an image sensor according to an embodiment of the present invention.

[0119] Referring to FIG. 25, an electronic device 1000 includes a camera module group 1100, an application processor 1200, a PMIC 1300, and an external memory 1400.

[0120] The camera module group 1100 includes multiple camera modules (1100a, 1100b, 1100c). Although the drawings show an embodiment in which three camera modules (1100a, 1100b, 1100c) are arranged, the embodiment is not limited thereto. In some embodiments, the camera module group 1100 is modified to include only two camera modules. In some embodiments, the camera module group 1100 is modified to include n camera modules (n is a natural number greater than or equal to 4). In one embodiment, at least one of the multiple camera modules (1100a, 1100b, 1100c) included in the camera module group 1100 includes an image sensor according to any of the embodiments previously described with reference to FIGS. 1 to 24.

[0121] The detailed configuration of camera module 1100b will be described in more detail below with reference to FIG. 26, but the following description can also be applied to camera modules (1100a, 1100b) that differ depending on the embodiment.

[0122] Referring to FIG. 26, the camera module 1100b includes a prism 1105, an optical path folding element (hereinafter referred to as “OPFE”) 1110, an actuator 1130, an image sensing device 1140, and a storage unit 1150.

[0123] Prism 1105 includes a reflecting surface 1107 made of a light-reflecting material, and changes the path of light L incident from the outside.

[0124] In some embodiments, the prism 1105 changes the path of light L incident in the second direction X to a third direction Y perpendicular to the second direction X. The prism 1105 also changes the path of light L incident in the second direction X to the perpendicular third direction Y by rotating the reflective surface 1107 of the light-reflecting material around the central axis 1106 in the direction A or by rotating the central axis 1106 in the direction B. At this time, the OPFE 1110 also moves in the first direction Z perpendicular to the second direction X and the third direction Y.

[0125] In some embodiments, as shown, the maximum rotation angle of prism 1105 in the A direction is less than or equal to 15 degrees in the positive (+) A direction and greater than 15 degrees in the negative (-) A direction, although embodiments are not limited thereto.

[0126] In some embodiments, the prism 1105 moves around 20 degrees in the plus (+) or minus (-) B direction, or between 10 degrees and 20 degrees, or between 15 degrees and 20 degrees, where the angle of movement is the same angle in the plus (+) or minus (-) B direction, or to a similar angle in the range of around 1 degree.

[0127] In some embodiments, the prism 1105 moves the reflective surface 1107 of the light-reflecting material in a first direction (eg, Z direction) parallel to the extension direction of the central axis 1106 .

[0128] The OPFE 1110 includes, for example, a group of m optical lenses (where m is a natural number). The m lenses move in a third direction Y to change the optical zoom ratio of the camera module 1100b. For example, if the basic optical zoom ratio of the camera module 1100b is Z, then when the m optical lenses included in the OPFE 1110 are moved, the optical zoom ratio of the camera module 1100b is changed to an optical zoom ratio of 3Z, 5Z, or more than 5Z.

[0129] The actuator 1130 moves the OPFE 1110 or the optical lens (hereinafter referred to as the optical lens) to a specific position. For example, the actuator 1130 adjusts the position of the optical lens so that the image sensor 1142 is located at the focal length of the optical lens for accurate sensing.

[0130] The image sensing device 1140 includes an image sensor 1142, control logic 1144, and memory 1146. The image sensor 1142 senses an image of a sensing target using light L provided through an optical lens. The control logic 1144 controls the overall operation of the camera module 1100b. For example, the control logic 1144 controls the operation of the camera module 1100b in response to a control signal provided via a control signal line CSLb.

[0131] The memory 1146 stores information necessary for the operation of the camera module 1100b, such as calibration data 1147. The calibration data 1147 includes information necessary for the camera module 1100b to generate image data using light L provided from an external source. The calibration data 1147 includes, for example, information about the degree of rotation, the focal length, and the optical axis. If the camera module 1100b is implemented in the form of a multi-state camera in which the focal length changes depending on the position of the optical lens, the calibration data 1147 includes a focal length value for each position (or state) of the optical lens and information about autofocusing.

[0132] The storage unit 1150 stores image data sensed via the image sensor 1142. The storage unit 1150 is disposed outside the image sensing device 1140 and is implemented in a stacked form with the sensor chip that constitutes the image sensing device 1140. In some embodiments, the storage unit 1150 is implemented in an EEPROM (Electrically Erasable Programmable Read-Only Memory), but the embodiment is not limited thereto.

[0133] 25 and 26 together, in some embodiments, each of the multiple camera modules (1100a, 1100b, 1100c) includes an actuator 1130. This causes each of the multiple camera modules (1100a, 1100b, 1100c) to include the same or different calibration data 1147 depending on the operation of the actuator 1130 included therein.

[0134] In some embodiments, one of the multiple camera modules (1100a, 1100b, 1100c) (e.g., 1100b) is a folded lens type camera module including the prism 1105 and OPFE 1110 described above, and the remaining camera modules (e.g., 1100a, 1100b) are vertical type camera modules that do not include the prism 1105 and OPFE 1110, but the embodiments are not limited to this.

[0135] In some embodiments, one of the camera modules (1100a, 1100b, 1100c) is a vertical depth camera that extracts depth information using, for example, infrared rays (IR). In this case, the application processor 1200 can merge image data provided by the vertical depth camera with image data provided by another camera module (1100a or 1100b) to generate a 3D depth image.

[0136] In some embodiments, at least two camera modules (e.g., 1100a, 1100b) of the plurality of camera modules (1100a, 1100b, 1100c) have different fields of view (fields of view), for example, but not limited to, at least two camera modules (e.g., 1100a, 1100b) of the plurality of camera modules (1100a, 1100b, 1100c) have different optical lenses.

[0137] In some embodiments, the camera modules (1100a, 1100b, 1100c) each have a different viewing angle, and in this case, the optical lenses included in the camera modules (1100a, 1100b, 1100c) are also different, but this is not limiting.

[0138] In some embodiments, the multiple camera modules (1100a, 1100b, 1100c) are arranged to be physically separated from one another. That is, the multiple camera modules (1100a, 1100b, 1100c) do not share the sensing area of ​​one image sensor 1142, but an independent image sensor 1142 is arranged inside each of the multiple camera modules (1100a, 1100b, 1100c).

[0139] 25 again, the application processor 1200 includes an image processing unit 1210, a memory controller 1220, and an internal memory 1230. The application processor 1200 is realized separately from the multiple camera modules (1100a, 1100b, 1100c). For example, the application processor 1200 and the multiple camera modules (1100a, 1100b, 1100c) are realized separately on different semiconductor chips.

[0140] The image processing device 1210 includes a number of sub-image processors (1212a, 1212b, 1212c), an image generator 1214, and a camera module controller 1216.

[0141] The image processing device 1210 includes a plurality of sub-image processors (1212a, 1212b, 1212c) whose number corresponds to the number of the camera modules (1100a, 1100b, 1100c).

[0142] Image data generated from each camera module (1100a, 1100b, 1100c) is provided to the corresponding sub-image processor (1212a, 1212b, 1212c) via separate image signal lines (ISLa, ISLb, ISLc). For example, image data generated from camera module 1100a is provided to sub-image processor 1212a via image signal line ISLa, image data generated from camera module 1100b is provided to sub-image processor 1212b via image signal line ISLb, and image data generated from camera module 1100c is provided to sub-image processor 1212c via image signal line ISLc. Such image data transfer is performed using, for example, a camera serial interface (CSI) based on MIPI (Mobile Industry Processor Interface), but the embodiment is not limited thereto.

[0143] On the other hand, in some embodiments, one sub-image processor is arranged to correspond to multiple camera modules. For example, sub-image processor 1212a and sub-image processor 1212c are not implemented separately from each other as shown in the figure, but are integrated into one sub-image processor, and image data provided from camera module 1100a and camera module 1100c is selected via a selection element (e.g., a multiplexer) and then provided to the integrated sub-image processor.

[0144] The image data provided to each sub-image processor (1212a, 1212b, 1212c) is provided to an image generator 1214. The image generator 1214 generates an output image using the image data provided from each sub-image processor (1212a, 1212b, 1212c) according to image generating information or a mode signal.

[0145] Specifically, the image generator 1214 generates an output image by merging at least a portion of the image data generated from the camera modules 1100a, 1100b, and 1100c having different viewing angles in response to the image generation information or mode signal. Also, the image generator 1214 selects one of the image data generated from the camera modules 1100a, 1100b, and 1100c having different viewing angles in response to the image generation information or mode signal to generate an output image.

[0146] In some embodiments, the image generation information includes a zoom signal or zoom factor, and in some embodiments, the mode signal is based on a mode selected by, for example, a user.

[0147] When the image generation information is a zoom signal (zoom factor) and each camera module (1100a, 1100b, 1100c) has a different field of view (viewing angle), the image generator 1214 performs different operations depending on the type of zoom signal. For example, when the zoom signal is a first signal, the image generator 1214 merges the image data output from camera module 1100a and the image data output from camera module 1100c, and then generates an output image using the merged image signal and the image data output from camera module 1100b, which was not used in the merging. When the zoom signal is a second signal different from the first signal, the image generator 1214 does not merge the image data, but instead selects one of the image data output from each camera module (1100a, 1100b, 1100c) to generate an output image. However, the embodiment is not limited thereto, and the method of processing image data may be modified as needed.

[0148] In some embodiments, the image generator 1214 receives multiple image data with different exposure times from at least one of multiple sub-image processors (1212a, 1212b, 1212c) and performs HDR (high dynamic range) processing on the multiple image data to generate merged image data with an increased dynamic range.

[0149] The camera module controller 1216 provides control signals to each of the camera modules (1100a, 1100b, 1100c). The control signals generated by the camera module controller 1216 are provided to the corresponding camera modules (1100a, 1100b, 1100c) via separate control signal lines (CSLa, CSLb, CSLc).

[0150] One of the multiple camera modules (1100a, 1100b, 1100c) is designated as a master camera (e.g., 1100b) according to image generation information including a zoom signal or a mode signal, and the remaining camera modules (e.g., 1100a, 1100c) are designated as slave cameras. Such information is included in a control signal and provided to the corresponding camera modules (1100a, 1100b, 1100c) via separate control signal lines (CSLa, CSLb, CSLc).

[0151] The camera module operating as the master and the slave changes depending on the zoom factor or the operation mode signal. For example, when the viewing angle of camera module 1100a is wider than that of camera module 1100b and the zoom factor indicates a low zoom magnification, camera module 1100b operates as the master and camera module 1100a operates as the slave. Conversely, when the zoom factor indicates a high zoom magnification, camera module 1100a operates as the master and camera module 1100b operates as the slave.

[0152] In some embodiments, the control signals provided from the camera module controller 1216 to each of the camera modules (1100a, 1100b, 1100c) include a sync enable signal. For example, if the camera module 1100b is the master camera and the camera modules (1100a, 1100c) are slave cameras, the camera module controller 1216 transfers the sync enable signal to the camera module 1100b. Upon receiving the sync enable signal, the camera module 1100b generates a sync signal based on the received sync enable signal and provides the generated sync signal to the camera modules (1100a, 1100c) via the sync signal line SSL. The camera module 1100b and the camera modules (1100a, 1100c) transfer image data to the application processor 1200 in synchronization with the sync signal.

[0153] In some embodiments, the control signals provided by the camera module controller 1216 to the camera modules (1100a, 1100b, 1100c) include mode information in response to the mode signal, and based on such mode information, the camera modules (1100a, 1100b, 1100c) operate in a first operational mode and a second operational mode associated with sensing speeds.

[0154] In a first operating mode, the camera modules (1100a, 1100b, 1100c) generate image signals at a first rate (e.g., generate image signals at a first frame rate), encode the image signals at a second rate higher than the first rate (e.g., encode image signals at a second frame rate higher than the first frame rate), and transfer the encoded image signals to the application processor 1200. In this case, the second rate may be 30 times or less than the first rate.

[0155] The application processor 1200 stores the received image signal, i.e., the encoded image signal, in the internal memory 1230 or the external storage 1400 of the application processor 1200, and then reads and decodes the encoded image signal from the memory 1230 or the storage 1400, and displays image data generated based on the decoded image signal. For example, a corresponding sub-processor among the multiple sub-processors (1212a, 1212b, 1212c) of the image processing device 1210 performs decoding and image processing on the decoded image signal.

[0156] In the second operating mode, the multiple camera modules (1100a, 1100b, 1100c) generate image signals at a third rate lower than the first rate (e.g., generate image signals at a third frame rate lower than the first frame rate) and transfer the image signals to the application processor 1200. The image signals provided to the application processor 1200 are not encoded signals. The application processor 1200 performs image processing on the received image signals or stores the image signals in the memory 1230 or the storage 1400.

[0157] The PMIC 1300 supplies power, such as a power supply voltage, to each of the multiple camera modules (1100a, 1100b, and 1100c). For example, under the control of the application processor 1200, the PMIC 1300 supplies a first power to the camera module 1100a via a power signal line PSLa, a second power to the camera module 1100b via a power signal line PSLb, and a third power to the camera module 1100c via a power signal line PSLc.

[0158] The PMIC 1300 generates power and adjusts the power level corresponding to each of the camera modules (1100a, 1100b, 1100c) in response to a power control signal PCON from the application processor 1200. The power control signal PCON includes a power adjustment signal for each operation mode of the camera modules (1100a, 1100b, 1100c). For example, the operation mode may include a low power mode, in which case the power control signal PCON includes information about the camera module operating in the low power mode and the power level to be set. The power levels provided to each of the camera modules (1100a, 1100b, 1100c) may be the same or different. Furthermore, the power levels may be dynamically changed.

[0159] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is not limited to the above-described embodiments and can be modified in various ways without departing from the technical concept of the present invention. [Explanation of symbols]

[0160] 1, 100, 200, 1142 image sensors 10. 100A~400A pixel array 20 Logic Circuits 21 Row Driver 22 Readout circuit 23 Column Driver 24 Control Logic 110 Substrate 111, 112 1st page, 2nd page 115 Mask Layer 120 color filters 130 Light transmission layer 160 Multiple Elements 170 Wiring Pattern 180 insulating layer 1000 electronic devices 1100 camera modules 1100a, 1100b, 1100c camera modules 1105 Prism 1106 Center axis 1107 Reflective surface 1110 OPFE (Optical Path Folding Element) 1130 Actuator 1140 Image sensing device 1142 Image Sensor 1144 Control Logic 1146 memory 1147 Calibration Data 1150 Preservation Department 1200 Application Processor 1210 Image Processing Device 1212a, 1212b, 1212c Sub-Image Processors 1214 Image Generator 1216 Camera Module Controller 1220 memory controller 1230 internal memory 1300 PMIC 1400 external memory CFA Color Filter Array CSLa, CSLb, CSLc control signal lines DTI isolation film DX drive transistor FD Floating diffusion region H Trench ISLa, ISLb, ISLc image signal lines ML1, ML2 1st and 2nd microlenses OF overflow area PCON Power Control Signal PD photodiode PD1~PD4 1st to 4th photodiodes PG Pixel Group PG1, PG1a, PG1b First pixel group PG2, PG2a, PG2b Second pixel group PSLa, PSLb, PSLc Power Signal Lines PX unit pixel PXC Pixel Circuit RG Reset gate (drive line) RX reset transistor SG Select gate (drive line) SPG Subpixel Group SPG1, SPG1a, SPG1b First subpixel group SPG2, SPG2a, SPG2b Second subpixel group SSL Sync Signal Line SX select transistor TG1~TG4 1st to 4th transfer gates TX1 to TX4 First to fourth transfer transistors V DD Power supply voltage Vout output line

Claims

1. a pixel array including a plurality of unit pixels arranged in a 4x4 pattern in a second direction parallel to an upper surface of a substrate having a first surface and a second surface facing each other in a first direction and in a third direction perpendicular to the second direction, the unit pixels sharing one floating diffusion region for each 2x2 array, and a plurality of first pixel groups and a plurality of second pixel groups alternately arranged in the second direction and the third direction; a logic circuit for acquiring pixel signals from the plurality of unit pixels; the plurality of first pixel groups and the plurality of second pixel groups include an isolation film disposed between the plurality of unit pixels, a photodiode disposed inside the substrate in each of the plurality of unit pixels, and a color filter disposed on the first surface; Each of the plurality of unit pixels included in the plurality of first pixel groups includes a first microlens disposed on the color filter, the plurality of unit pixels included in the plurality of second pixel groups include a second microlens shared by each of the unit pixels in a 2×2 array, Each of the plurality of second pixel groups includes an overflow region for transferring charge generated from the photodiode to an adjacent photodiode.

2. The image sensor of claim 1 , wherein a center of the second microlens overlaps the floating diffusion region in the first direction.

3. The image sensor of claim 1 , wherein the color filters corresponding to the plurality of unit pixels in each of the first pixel groups and the second pixel groups have the same color.

4. the color filters included in the plurality of first pixel groups are green; The image sensor according to claim 3 , wherein the color filters included in the plurality of second pixel groups are red or blue.

5. the color filters included in the plurality of first pixel groups are red or blue; The image sensor according to claim 3 , wherein the color filters included in the second pixel groups are green.

6. a pixel array including a plurality of sub-pixel groups arranged in a 2×2 pattern in a second direction parallel to an upper surface of the substrate, the second direction being perpendicular to the upper surface of the substrate, the first direction being a first surface and a second surface facing each other in a first direction, the sub-pixel groups being each composed of a plurality of first sub-pixel groups and a plurality of second sub-pixel groups each including a plurality of unit pixels sharing one floating diffusion region in each of the 2×2 arrays; a logic circuit for acquiring pixel signals from the plurality of unit pixels; each of the plurality of sub-pixel groups is adjacent to one first sub-pixel group and one second sub-pixel group in the second direction and the third direction, and includes: an isolation layer disposed between the plurality of unit pixels and isolated from each other in the second direction and the third direction in a region adjacent to the floating diffusion region; a photodiode disposed inside the substrate in each of the plurality of unit pixels; and a color filter disposed on the first surface; Each of the plurality of unit pixels included in the plurality of first sub-pixel groups includes a first microlens disposed on the color filter, each of the second sub-pixel groups includes a second microlens shared by the unit pixels included in the second sub-pixel groups; a separation length of the isolation film included in the plurality of first sub-pixel groups in the second direction and the third direction is shorter than a separation length of the isolation film included in the plurality of second sub-pixel groups.

7. 7. The image sensor of claim 6, wherein each of the plurality of second sub-pixel groups includes an overflow region for transferring charges generated from the photodiode to an adjacent photodiode.

8. The image sensor according to claim 6 , wherein the green color filter is disposed on an upper surface of the first sub-pixel group.

9. the red or blue color filter is disposed on an upper surface of the second subpixel group; The image sensor according to claim 8 , wherein the green color filter is disposed on an upper surface of at least one of the first sub-pixel group.

10. a pixel array including a plurality of unit pixels defined by isolation layers extending in a first direction perpendicular to an upper surface of the substrate, arranged in a 4x4 pattern along a second direction parallel to the upper surface of the substrate and a third direction perpendicular to the second direction, each unit pixel including a photodiode disposed within the substrate, and each unit pixel including a 2x2 array sharing one floating diffusion region, and including a plurality of first pixel groups and a plurality of second pixel groups alternately arranged in the second direction and the third direction; a logic circuit for acquiring pixel signals from the plurality of unit pixels; a plurality of first microlenses having a first diameter and corresponding to each of the plurality of unit pixels are disposed on an upper surface of the plurality of first pixel groups; a plurality of second microlenses having a second diameter larger than the first diameter are disposed on an upper surface of the plurality of second pixel groups; The image sensor, wherein the pixel signals acquired from unit pixels sharing each of the plurality of second microlenses include autofocus pixel signals for the second direction and the third direction.

Images