Image sensor and arrangement

Abstract

The utility model provides a kind of image sensor and arrangement structure, wherein, image sensor includes first type pixel unit, first type pixel unit further includes first photosensitive part, second photosensitive part and first floating diffusion area.The first photosensitive part includes first photosensitive element and first transmission tube, wherein, the control end of first transmission tube and first end are coupled power supply potential, the second end of first transmission tube is coupled reference potential via first photosensitive element;The second photosensitive part includes second photosensitive element and second transmission tube, wherein, the control end of second transmission tube receives first transmission control signal, the first end of second transmission tube is coupled first floating diffusion area, the second end of second transmission tube is coupled reference potential via second photosensitive element.The utility model solves the problem of error caused by the mutual influence between the covering object and adjacent pixels in the prior art.

Description

Technical Field

[0001] This utility model belongs to the field of image sensor technology, and in particular relates to an image sensor and its arrangement structure. Background Technology

[0002] Masked phase detection autofocus (PDAF) works by covering half of the pixels and using a pair of photosensitive elements to detect phase differences. However, the half of the pixels covered cannot be used for imaging, essentially introducing dead pixels into the image sensor. When adjacent pixels affect the covered pixels (such as through electronic blooming), it introduces errors into this PDAF method; conversely, the covered pixels also affect adjacent pixels due to the covering material, thus introducing errors into those adjacent pixels.

[0003] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this utility model and facilitating understanding by those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because they have been described in the background section of this utility model. Utility Model Content

[0004] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide an image sensor and its arrangement structure to solve the problem of error caused by the mutual influence between the covering object and adjacent pixels in the prior art.

[0005] To achieve the above and other related objectives, this utility model provides an image sensor, including a first type of pixel unit, wherein:

[0006] The first type of pixel unit includes a first photosensitive part, a second photosensitive part, and a first floating diffusion region;

[0007] The first photosensitive part includes a first photosensitive element and a first transmission tube, wherein the control terminal and the first terminal of the first transmission tube are coupled to a power supply potential, and the second terminal of the first transmission tube is coupled to a reference potential via the first photosensitive element.

[0008] The second photosensitive part includes a second photosensitive element and a second transmission tube, wherein the control terminal of the second transmission tube receives a first transmission control signal, the first end of the second transmission tube is coupled to the first floating diffusion region, and the second end of the second transmission tube is coupled to a reference potential via the second photosensitive element.

[0009] Optionally, the first type of pixel unit includes a first reset part and a first readout part, or the first type of pixel unit further includes a first gain part;

[0010] The first reset unit includes a first reset transistor, wherein the control terminal of the first reset transistor receives a first reset control signal, the first terminal of the first reset transistor is coupled to a power supply potential, and the second terminal of the first reset transistor is coupled to the first floating diffusion region.

[0011] The first readout unit includes a first source follower transistor (RST) and a first select transistor. The control terminal of the first RST is coupled to the first floating diffusion region, the first terminal of the first RST is coupled to a variable potential, the second terminal of the first RST is coupled to the first terminal of the first select transistor, the control terminal of the first select transistor receives a first select control signal, and the second terminal of the first select transistor is coupled to the corresponding column line.

[0012] When a first gain section is included, the first gain section includes a first gain transistor, wherein the control terminal of the first gain transistor receives a first gain control signal, and the first and second ends of the first gain transistor are coupled between the second end of the first reset transistor and the first floating diffusion region; or, the first end of the first gain transistor is coupled to the first floating diffusion region, and the second end of the first gain transistor is coupled to a reference potential via a first gain capacitor.

[0013] Optionally, the control end and the first end of the first transmission tube are also coupled to the first floating diffusion region.

[0014] Optionally, the first floating diffusion region includes a first floating diffusion node and a second floating diffusion node, which are separately arranged from each other; wherein, the control end and the first end of the first transmission tube are coupled to the first floating diffusion node, or the first floating diffusion node serves as the first end of the first transmission tube and the control end of the first transmission tube is coupled to the first floating diffusion node, and the first end of the second transmission tube is coupled to the second floating diffusion node.

[0015] Optionally, the first type of pixel unit further includes a first overflow portion;

[0016] The first overflow section includes a first overflow tube and a first overflow capacitor, wherein the control terminal of the first overflow tube receives a first overflow control signal, the first end of the first overflow tube is coupled to the first floating diffusion region, and the second end of the first overflow tube is coupled to a reference potential via the first overflow capacitor.

[0017] Alternatively, when the first type of pixel unit includes a first gain section and the first end and the second end of the first gain transistor are coupled between the second end of the first reset transistor and the first floating diffusion region, the first end of the first overflow transistor is coupled to the first floating diffusion region and the second end of the first gain transistor is coupled to the first floating diffusion region; or, the first end of the first overflow transistor is changed from being coupled to the first floating diffusion region to being coupled to the first end of the first gain transistor.

[0018] Alternatively, when the first type of pixel unit includes a first gain section and the second end of the first gain transistor is coupled to the first floating diffusion region and the first end of the first gain transistor is coupled to a reference potential through a first gain capacitor, the first end of the first overflow transistor is coupled to the first floating diffusion region.

[0019] Optionally, the first floating diffusion region includes a first floating diffusion node and a second floating diffusion node, which are separately disposed and electrically isolated from each other; wherein, the control end and the first end of the first transmission tube are coupled to the first floating diffusion node, or the first floating diffusion node serves as the first end of the first transmission tube and the control end of the first transmission tube is coupled to the first floating diffusion node, and the first end of the second transmission tube is coupled to the second floating diffusion node.

[0020] Optionally, the number of the first type of pixel units includes at least two, wherein the two first type of pixel units form a phase focusing pixel pair; in the two different first type of pixel units corresponding to the phase focusing pixel pair, the two second photosensitive parts are arranged opposite each other to detect the phase difference.

[0021] Optionally, it also includes a second type of pixel unit, wherein:

[0022] The second type of pixel unit includes a third photosensitive part, a fourth photosensitive part, and a second floating diffusion region; the interconnection method of the corresponding transmission tube and the corresponding photosensitive element in the third photosensitive part and the fourth photosensitive part is the same as that in the second photosensitive part; the second floating diffusion region includes a third floating diffusion node and a fourth floating diffusion node that are separately arranged, and the two floating diffusion nodes are electrically interconnected with each other.

[0023] Alternatively, the second type of pixel unit may further include a second reset section and a second readout section; the interconnection method of the second reset transistor in the second reset section is the same as that of the first reset section, and the interconnection method of the second source follower transistor and the second select transistor in the second readout section is the same as that of the first readout section.

[0024] Optionally, the second type of pixel unit further includes a second gain section and / or a second overflow section; the interconnection method of the second gain transistor in the second gain section is the same as that of the first gain section, and the interconnection method of the second overflow transistor and the second overflow capacitor in the second overflow section is the same as that of the first overflow section.

[0025] This utility model also provides an image sensor arrangement structure as described in any one of the above claims, comprising:

[0026] The first type of pixel area includes a first region and a second region, which are symmetrically arranged on both sides of the first direction path, wherein the first direction path and the second direction path are intersected and have an overlapping area.

[0027] A first photosensitive element is disposed in the first region, and a second photosensitive element is disposed in the second region, wherein a first transmission tube is disposed at least at the corner of the first photosensitive element near the overlapping region, and a second transmission tube is disposed at least at the corner of the second photosensitive element near the overlapping region;

[0028] The first floating diffusion zone is at least disposed in the second region, and is disposed in the second directional channel near the overlapping region.

[0029] Optionally, when the first reset section and the first readout section are included, the first source follower tube is disposed at the overlapping area, the first reset tube and the first selection tube are disposed in the first direction channel, and are symmetrically disposed on both sides of the first source follower tube.

[0030] When a first gain section is also included, the first gain tube is disposed in the second direction channel;

[0031] When a first overflow portion is also included, the first overflow pipe is disposed in the second direction channel;

[0032] When the first gain section and the first overflow section are also included, the first gain tube and the first overflow tube are disposed in the second direction channel and are symmetrically disposed on both sides of the first source follower tube.

[0033] Optionally, the first floating diffusion region includes a first floating diffusion node and a second floating diffusion node, wherein the first floating diffusion node is disposed in the second direction channel of the first region, the second floating diffusion node is disposed in the second direction channel of the second region, and the first floating diffusion node and the second floating diffusion node are symmetrically disposed on both sides of the overlapping region.

[0034] Optionally, when the first overflow portion is not included, the first floating diffusion node and the second floating diffusion node are electrically isolated from or electrically interconnected with each other; when the first overflow portion is included, the first floating diffusion node and the second floating diffusion node are electrically isolated from each other; and / or, when the first gain portion is also included, an isolation portion is formed between the first gain transistor in the first gain portion and the first floating diffusion node, and the second floating diffusion node is electrically interconnected with the first gain transistor; and / or, when the first gain portion and the first readout portion are also included, the first transmission transistor and the first floating diffusion node are electrically interconnected through the metal interconnects of the first metal wiring layer, the first source follower transistor in the first readout portion is electrically interconnected with the second floating diffusion node through the metal interconnects of the first metal wiring layer, and the second floating diffusion node is electrically interconnected with the corresponding first gain transistor through the metal interconnects of the second metal wiring layer.

[0035] Optionally, it also includes:

[0036] The second type of pixel region has the same device arrangement as the first type of pixel region; wherein, when the second floating diffusion region includes a third floating diffusion node and a fourth floating diffusion node, the two floating diffusion nodes are electrically interconnected with each other.

[0037] Optionally, when a second gain section is also included, the second gain section and the second floating diffusion region are electrically interconnected directly through doping sharing; and / or, the third floating diffusion node and the fourth floating diffusion node are electrically interconnected with the second source follower in the second readout section through the metal interconnects of the first metal wiring layer.

[0038] As described above, the image sensor and its arrangement structure of this invention separate a photosensitive part into an independent first photosensitive part and a second photosensitive part. The control terminal and the first terminal of the first transmission tube in the first photosensitive part are coupled to the power supply potential to clear the charge on the first photosensitive element. Without the aid of a light-blocking plate, the first photosensitive part forms a non-photosensitive structure, while the second photosensitive part forms a photosensitive structure as a normal pixel, thereby achieving phase focusing. Since no light-blocking plate is needed during the phase focusing process of this invention, the influence between adjacent pixels can be avoided, thereby reducing errors and improving accuracy. Attached Figure Description

[0039] Figure 1 The diagram shown is a structural schematic of an image sensor according to an embodiment of this utility model.

[0040] Figure 2 The diagram shown is a structural schematic of a first type of pixel unit in an embodiment of this utility model.

[0041] Figure 3 Displayed as Figure 2 A schematic diagram of a structure with an added first gain unit.

[0042] Figure 4 Displayed as Figure 2 Another structural diagram with an added first gain section.

[0043] Figure 5 Displayed as Figure 2 A schematic diagram of a structure with an added first overflow section.

[0044] Figure 6 Displayed as Figure 3 A schematic diagram of a structure with an added first overflow section.

[0045] Figure 7 Displayed as Figure 4 A schematic diagram of a structure with an added first overflow section.

[0046] Figure 8 Displayed as Figure 3 Another structural diagram showing the addition of a first overflow section.

[0047] Figure 9 The diagram shown is a structural schematic of a second type of pixel unit in an embodiment of this utility model.

[0048] Figure 10 The diagram shown is a schematic diagram of an arrangement structure corresponding to the first type of pixel unit in an embodiment of this utility model.

[0049] Figure 11 This is a schematic diagram of an arrangement structure corresponding to the second type of pixel unit in an embodiment of this utility model.

[0050] Figure 12 The diagram shown is a schematic diagram of an electrical interconnection structure corresponding to the first type of pixel unit in this embodiment of the present invention.

[0051] Figure 13 The diagram shown is a schematic diagram of an electrical interconnection structure corresponding to the second type of pixel unit in an embodiment of this utility model.

[0052] Component designation explanation

[0053] 100 Image Sensor

[0054] 110 First type pixel unit

[0055] 111 First Photosensitive Section

[0056] 112 Second Photosensitive Section

[0057] 113 First Reset Part

[0058] 114 First Reading Section

[0059] 115 First Gain Section

[0060] 116 First Overflow Section

[0061] 120 Type II pixel units

[0062] 121 Third Photosensitive Section

[0063] 122 Fourth Photosensitive Section

[0064] 123 Second Reset Section

[0065] 124 Second Reading Section

[0066] 125 Second Gain Section

[0067] 126 Second Overflow Section Detailed Implementation

[0068] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.

[0069] Please see Figures 1 to 13 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Therefore, the illustrations only show the components related to this utility model and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the shape, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0070] like Figure 1 As shown, this embodiment provides an image sensor 100, including a first type of pixel unit 110, and further including a second type of pixel unit 120; the first type of pixel unit 110 and the second type of pixel unit 120 constitute a pixel array, wherein the number of the first type of pixel unit 110 is less than the number of the second type of pixel unit 120.

[0071] In this embodiment, the number of first-type pixel units 110 includes at least two. In practical applications, the number of first-type pixel units 110 is an even number. Furthermore, two first-type pixel units 110 form a phase-detection pixel pair (usually set in the same column) to achieve phase detection autofocus (PDAF) by detecting the phase difference.

[0072] It should be noted that the second type of pixel unit 120 is provided with color filters, typically including a red filter (R), a green filter (G), and a blue filter (B). Of course, it is also feasible to provide other color filters, such as a white filter (W), which has no substantial impact on the implementation of the solution in this embodiment. In addition, the first type of pixel unit 110 may be provided with color filters, for example, a green filter (G). Of course, it is also possible not to provide color filters, which has no substantial impact on the implementation of the solution in this embodiment; and the first type of pixel unit 110 is not provided with a light-shielding plate.

[0073] like Figures 2 to 8 As shown, the first type of pixel unit 110 includes a first photosensitive part 111, a second photosensitive part 112 and a first floating diffusion region FD1. Furthermore, it also includes a first reset part 113 and a first readout part 114. Even further, it also includes at least one of a first gain part 115 and a first overflow part 116.

[0074] The first photosensitive unit 111 includes a first photosensitive element PD11 and a first transmission tube M11, such as Figure 2 As shown; wherein, the control terminal and the first terminal of the first transmission tube M11 are coupled to the power supply potential AVDD, and the second terminal of the first transmission tube M11 is coupled to the reference potential (e.g., ground potential or negative potential) via the first photosensitive element PD11.

[0075] In practical applications, the number of the first photosensitive element PD11 and the first transmission tube M11 can be one or more than one, and there is no restriction on this. When there are multiple first photosensitive elements PD11 and first transmission tubes M11, the first photosensitive elements PD11 and the first transmission tubes M11 are set in a one-to-one correspondence.

[0076] The second photosensitive unit 112 includes a second photosensitive element PD12 and a second transmission tube M12, such as Figure 2 As shown; wherein, the control terminal of the second transmission tube M12 receives the first transmission control signal TX1, the first end of the second transmission tube M12 is coupled to the first floating diffusion region FD1, and the second end of the second transmission tube M12 is coupled to the reference potential (e.g., ground potential or negative potential) via the second photosensitive element PD12.

[0077] In practical applications, the number of the second photosensitive element PD12 and the second transmission tube M12 can be one or more than one, and there is no restriction on this. When there are multiple second photosensitive elements PD12 and second transmission tubes M12, the second photosensitive elements PD12 and the second transmission tubes M12 are set in a one-to-one correspondence.

[0078] In this embodiment, the number of the first photosensitive element PD11 and the first transmission tube M11 is the same as the number of the second photosensitive element PD12 and the second transmission tube M12, for example, two in each case; in addition, the total number of photosensitive elements in the first type of pixel unit 110 is usually the same as the total number of photosensitive elements in the second type of pixel unit 120.

[0079] The first reset unit 113 includes a first reset transistor M21, such as Figure 2 As shown; wherein, the control terminal of the first reset transistor M21 receives the first reset control signal RST1, the first terminal of the first reset transistor M21 is coupled to the power supply potential AVDD, and the second terminal of the first reset transistor M21 is coupled to the first floating diffusion region FD1.

[0080] The first readout section 114 includes a first source follower tube M31 and a first selector tube M41, such as Figure 2As shown; wherein, the control terminal of the first source follower transistor M31 is coupled to the first floating diffusion region FD1, the first terminal of the first source follower transistor M31 is coupled to the variable potential VRSF, the second terminal of the first source follower transistor M31 is coupled to the first terminal of the first selection transistor M41, the control terminal of the first selection transistor M41 receives the first selection control signal SEL1, and the second terminal of the first selection transistor M41 is coupled to the corresponding column line. In practical applications, it is also feasible to couple the first terminal of the first source follower transistor M31 to the power supply potential AVDD, which has no substantial impact on the implementation of the scheme in this embodiment.

[0081] The first gain section 115 includes a first gain transistor M51, such as Figure 3 and Figure 4 As shown. In one example, such as Figure 3 As shown, the control terminal of the first gain transistor M51 receives the first gain control signal DCG1. The first and second terminals of the first gain transistor M51 are coupled between the second terminal of the first reset transistor M21 and the first floating diffusion region FD1. That is, the first terminal of the first gain transistor M51 is coupled to the second terminal of the first reset transistor M21, and the second terminal of the first gain transistor M51 is coupled to the first floating diffusion region FD1. In another example, such as... Figure 4 As shown, the control terminal of the first gain transistor M51 receives the first gain control signal DCG1. The first terminal of the first gain transistor M51 is coupled to the first floating diffusion region FD1, and the second terminal of the first gain transistor M51 is coupled to the reference potential (e.g., ground potential or negative potential) via the first gain capacitor C_DCG1. The first gain capacitor C_DCG1 can be a parasitic capacitance, such as the silicon substrate parasitic capacitance, or it can be a device capacitance, such as a MIM capacitor.

[0082] The first overflow section 116 includes a first overflow transistor M61 and a first overflow capacitor C11, such as Figures 5 to 7 As shown; wherein, the control terminal of the first overflow transistor M61 receives the first overflow control signal OF1, the first terminal of the first overflow transistor M61 is coupled to the first floating diffusion region FD1, and the second terminal of the first overflow transistor M61 is coupled to a reference potential (e.g., ground potential or negative potential) via the first overflow capacitor C11. When the first type pixel unit 110 does not include the first gain section 115, the interconnection method of the first overflow transistor M61 and the first overflow capacitor C11 is as follows. Figure 5 As shown; when the first type pixel unit 110 includes a first gain section 115 and the first and second ends of the first gain transistor M51 are coupled between the second end of the first reset transistor M21 and the first floating diffusion region FD1, the interconnection method of the first overflow transistor M61 and the first overflow capacitor C11 is as follows. Figure 6As shown; when the first type pixel unit 110 includes a first gain section 115 and the first gain transistor M51 and the first gain capacitor C_DCG1 are coupled between the first floating diffusion region FD1 and the reference potential, the interconnection method of the first overflow transistor M61 and the first overflow capacitor C11 is as follows. Figure 7 As shown.

[0083] As an alternative, when the first type of pixel unit 110 simultaneously includes a first gain section 115 and a first overflow section 116, and the first and second ends of the first gain transistor M51 are coupled between the second end of the first reset transistor M21 and the first floating diffusion region FD1, the first end of the first overflow transistor M61 can be changed from being coupled to the first floating diffusion region FD1 to being coupled to the first end of the first gain transistor M51, that is, the connection node coupled to the first reset transistor M21 and the first gain transistor M51, such as... Figure 8 As shown.

[0084] Regarding the first type of pixel unit 110 in this embodiment, in one implementation, particularly for the first type of pixel unit 110 that does not include the first overflow portion 116, its first floating diffusion region FD1 has a different design.

[0085] In one example, the first floating diffusion region FD1 is a complete node. In this case, the control terminal and the first terminal of the first transmission tube M11 in the first photosensitive unit 111 are only coupled to the power supply potential AVDD, and the first terminal of the second transmission tube M12 in the second photosensitive unit 112 is coupled to the first floating diffusion region FD1, as shown below. Figures 2 to 4 As shown. Of course, in addition to being coupled to the power supply potential AVDD, the control terminal and the first terminal of the first transmission tube M11 in the first photosensitive unit 111 can also be coupled to the first floating diffusion region FD1; in the no-overflow application, the second photosensitive unit 112 does not have charge overflow during the exposure process. Therefore, even if the control terminal and the first terminal of the first transmission tube M11 are also coupled to the first floating diffusion region FD1, it will not affect the exposure of the second photosensitive unit 112.

[0086] In another example, the first floating diffusion region FD1 is no longer a single node, but comprises two separate nodes: the first floating diffusion node FD11 and the second floating diffusion node FD12. The first floating diffusion node FD11 and the second floating diffusion node FD12 are electrically isolated from each other. In this example, the electrical isolation can be achieved through physical electrical isolation, i.e., by forming two isolated doped nodes during device fabrication. In this case, the control terminal and the first terminal of the first transmission tube M11 in the first photosensitive section 111 are also coupled to the first floating diffusion node FD11. Alternatively, the first floating diffusion node FD11 can be used as the first terminal of the first transmission tube M11, and the control terminal of the first transmission tube M11 can be coupled to the first floating diffusion node FD11. The first terminal of the second transmission tube M12 in the second photosensitive section 112 is then coupled to the second floating diffusion node FD12. Of course, in overflow-free applications, it is also feasible for the first floating diffusion node FD11 and the second floating diffusion node FD12 to be electrically interconnected, which will not affect the exposure of the second photosensitive section 112.

[0087] In addition, the first floating diffusion region FD1 of the first type of pixel unit 110, including the first overflow portion 116, also has a different design.

[0088] In one example, the first floating diffusion region FD1 is a complete node. In this case, the control terminal and the first terminal of the first transmission tube M11 in the first photosensitive unit 111 are only coupled to the power supply potential AVDD, and the first terminal of the second transmission tube M12 in the second photosensitive unit 112 is coupled to the first floating diffusion region FD1, as shown below. Figures 5 to 8 As shown; in the overflow application, the second photosensitive part 112 has charge overflow during the exposure process, but since the control terminal and the first terminal of the first transmission tube M11 are not coupled to the first floating diffusion region FD1, it will not affect the exposure of the second photosensitive part 112.

[0089] In another example, the first floating diffusion region FD1 is no longer a single node, but comprises two separate nodes: a first floating diffusion node FD11 and a second floating diffusion node FD12, wherein the first floating diffusion node FD11 and the second floating diffusion node FD12 are electrically isolated from each other. In this example, the electrical isolation can be achieved through physical electrical isolation, i.e., by forming two isolated doped nodes during device fabrication. In this case, the control terminal and the first terminal of the first transmission tube M11 in the first photosensitive section 111 are also coupled to the first floating diffusion node FD11, or the first floating diffusion node FD11 can be used as the first terminal of the first transmission tube M11 and the control terminal of the first transmission tube M11 can be coupled to the first floating diffusion node FD11, while the first terminal of the second transmission tube M12 in the second photosensitive section 112 is coupled to the second floating diffusion node FD12. In overflow applications, since the two diffusion nodes are electrically isolated from each other, they will not affect the overflow charge generated by the second photosensitive section 112 during exposure.

[0090] It should be noted that the separation of the two floating diffusion nodes in this embodiment means that the two floating diffusion nodes are designed independently in space, but it does not restrict whether the two floating diffusion nodes are electrically isolated or electrically interconnected. Electrical isolation and electrical interconnection are restrictions on the interconnection method between the two floating diffusion nodes, that is, whether they are electrically interconnected.

[0091] like Figure 9 As shown, the second type of pixel unit 120 includes a third photosensitive part 121, a fourth photosensitive part 122 and a second floating diffusion region FD2, and further includes a second reset part 123 and a second readout part 124, and even further includes at least one of a second gain part 125 and a second overflow part 126.

[0092] The third photosensitive unit 121 includes a third photosensitive element PD13 and a third transmission tube M13; wherein, the control terminal of the third transmission tube M13 receives a second transmission control signal TX2, the first terminal of the third transmission tube M13 is coupled to a second floating diffusion region FD2, and the second terminal of the third transmission tube M13 is coupled to a reference potential (e.g., ground potential or negative potential) via the third photosensitive element PD13.

[0093] The fourth photosensitive unit 122 includes a fourth photosensitive element PD14 and a fourth transmission tube M14; wherein, the control terminal of the fourth transmission tube M14 receives a second transmission control signal TX2, the first terminal of the fourth transmission tube M14 is coupled to a second floating diffusion region FD2, and the second terminal of the fourth transmission tube M14 is coupled to a reference potential (e.g., ground potential or negative potential) via the fourth photosensitive element PD14.

[0094] In this embodiment, the interconnection method of each device in the third photosensitive unit 121 and the fourth photosensitive unit 122 is the same. In practical applications, the number of devices in the third photosensitive unit 121 and the fourth photosensitive unit 122 is the same as that in the first photosensitive unit 111 and the second photosensitive unit 112, for example, two in each case, to form a four-shared pixel structure. Of course, it is also feasible to use other numbers to form other shared pixel structures, which has no substantial impact on the implementation of the scheme in this embodiment.

[0095] The second reset unit 123 includes a second reset transistor M22; wherein, the control terminal of the second reset transistor M22 receives a second reset control signal RST2, the first terminal of the second reset transistor M22 is coupled to the power supply potential AVDD, and the second terminal of the second reset transistor M22 is coupled to the second floating diffusion region FD2.

[0096] The second readout section 124 includes a second source follower transistor M32 and a second selector transistor M42. The control terminal of the second source follower transistor M32 is coupled to the second floating diffusion region FD2, the first terminal of the second source follower transistor M32 is coupled to the variable potential VRSF, the second terminal of the second source follower transistor M32 is coupled to the first terminal of the second selector transistor M42, the control terminal of the second selector transistor M42 receives the second selector control signal SEL2, and the second terminal of the second selector transistor M42 is coupled to the corresponding column line. In practical applications, it is also feasible to couple the first terminal of the second source follower transistor M32 to the power supply potential AVDD, which has no substantial impact on the implementation of the scheme in this embodiment.

[0097] The second gain section 125 includes a second gain transistor M52. In one example, such as... Figure 9 As shown, the control terminal of the second gain transistor M52 receives the second gain control signal DCG2. The first and second terminals of the second gain transistor M52 are coupled between the second terminal of the second reset transistor M22 and the second floating diffusion region FD2. That is, the first terminal of the second gain transistor M52 is coupled to the second terminal of the second reset transistor M22, and the second terminal of the second gain transistor M52 is coupled to the second floating diffusion region FD2. In another example, the control terminal of the second gain transistor M52 receives the second gain control signal DCG2. The first terminal of the second gain transistor M52 is coupled to the second floating diffusion region FD2, and the second terminal of the second gain transistor M52 is coupled to a reference potential (e.g., ground potential or negative potential) through the second gain capacitor C_DCG2. The second gain capacitor C_DCG2 can be a parasitic capacitance, such as the silicon substrate parasitic capacitance, or a device capacitance, such as a MIM capacitor.

[0098] The second overflow section 126 includes a second overflow transistor M62 and a second overflow capacitor C12. The control terminal of the second overflow transistor M62 receives a second overflow control signal OF2. The first terminal of the second overflow transistor M62 is coupled to the second floating diffusion region FD2, and the second terminal of the second overflow transistor M62 is coupled to a reference potential (e.g., ground potential or negative potential) via the second overflow capacitor C12. In practical applications, when the second type pixel unit 120 does not include the second gain section 125, or when the second type pixel unit 120 includes the second gain section 125 and the first and second terminals of the second gain transistor M52 are coupled between the second terminal of the second reset transistor M22 and the second floating diffusion region FD2, or when the second type pixel unit 120 includes the second gain section 125 and the second gain transistor M52 and the second gain capacitor C_DCG2 are coupled between the second floating diffusion region FD2 and the reference potential, the second overflow transistor M62 and the second overflow capacitor C12 can be interconnected as described above.

[0099] As an alternative, when the second type pixel unit 120 simultaneously includes a second gain section 125 and a second overflow section 126, and the first and second ends of the second gain transistor M52 are coupled between the second end of the second reset transistor M22 and the second floating diffusion region FD2, the first end of the second overflow transistor M62 can be changed from being coupled to the second floating diffusion region FD2 to being coupled to the first end of the second gain transistor M52, that is, the connection node coupled to the second reset transistor M22 and the second gain transistor M52. It should be noted that the relevant circuit diagram for the second overflow section 126 can be found in the diagram corresponding to the first overflow section 116 in the first type pixel unit 110, and will not be repeated here.

[0100] In the second type of pixel unit 120 of this embodiment, the second floating diffusion region FD2 has different designs. In one example, the second floating diffusion region FD2 is a complete node. In this case, the first end of the third transmission tube M13 in the third photosensitive unit 121 and the first end of the fourth transmission tube M14 in the fourth photosensitive unit 122 are both coupled to the second floating diffusion region FD2. In another example, the second floating diffusion region FD2 is no longer a complete node, but includes two separate nodes, namely, the third floating diffusion node FD21 and the fourth floating diffusion node FD22; wherein the third floating diffusion node FD21 and the fourth floating diffusion node FD22 are electrically interconnected. In this case, the first end of the third transmission tube M13 in the third photosensitive unit 121 is coupled to the third floating diffusion node FD21, and the first end of the fourth transmission tube M14 in the fourth photosensitive unit 122 is coupled to the fourth floating diffusion region FD22.

[0101] In practical applications, all transistors involved in the first type of pixel unit 110 and the second type of pixel unit 120 are NMOS transistors. Correspondingly, the control terminal refers to the gate terminal, the first terminal refers to the drain terminal, and the second terminal refers to the source terminal. Of course, it is also feasible for all transistors to be PMOS transistors, which has no substantial impact on the implementation of the scheme in this embodiment.

[0102] like Figure 10 and Figure 11 As shown, this embodiment also provides an arrangement structure for an image sensor 100, including the layout design of each device in the first type of pixel unit 110, and further including the layout design of each device in the second type of pixel unit 120; wherein, the image sensor 100 is implemented using the circuit structure described above in this embodiment.

[0103] In this embodiment, the layout area where the first type of pixel unit 110 is located is called the first type of pixel area, and the layout area where the second type of pixel unit 120 is located is called the second type of pixel area. The first type of pixel area and the second type of pixel area are arranged in an array. The number of first type of pixel areas is less than the number of second type of pixel areas. Usually, the second type of pixel areas are arranged around the first type of pixel area.

[0104] like Figure 10 As shown, the first type of pixel area includes a first region and a second region, as indicated by the dashed boxes on the left and right sides of the figure, respectively. The first region and the second region are symmetrically arranged on both sides of the first directional channel. Furthermore, the first region and the second region are also symmetrically arranged along the second directional channel. The first directional channel and the second directional channel intersect and have an overlapping area; for example, the first directional channel and the second directional channel are perpendicular to each other and have this overlapping area. In this embodiment, the first directional channel is a vertical channel, and the second directional channel is a horizontal channel.

[0105] A first photosensitive unit 111 is disposed in a first region; wherein, a first transmission tube M11 is disposed at least at the corner of the first photosensitive element PD11 near the overlapping region. In this embodiment, the first photosensitive unit 111 includes two first photosensitive elements PD11 and two first transmission tubes M11, wherein the two first photosensitive elements PD11 are respectively disposed in the first region on both sides of the second direction channel, and the two first transmission tubes M11 are correspondingly inclinedly disposed at the corner of the two first photosensitive elements PD11 near the overlapping region.

[0106] The second photosensitive unit 112 is disposed in the second region; wherein, the second transmission tube M12 is disposed at least at the corner of the second photosensitive element PD12 near the overlapping region. In this embodiment, the second photosensitive unit 112 includes two second photosensitive elements PD12 and two second transmission tubes M12, wherein the two second photosensitive elements PD12 are respectively disposed in the second region on both sides of the second direction channel, and the two second transmission tubes M12 are correspondingly inclinedly disposed at the corner of the two second photosensitive elements PD12 near the overlapping region.

[0107] Regarding phase-detection pixel pairs: In the two first-type pixel regions corresponding to the two different first-type pixel units 110, the two first regions are arranged opposite each other, and the two second regions are arranged opposite each other, so that the two first photosensitive units 111 are arranged opposite each other, and the two second photosensitive units 112 are also arranged opposite each other, so as to facilitate the detection of phase difference; for example, in the first first-type pixel region, the first region is located on the left side of the first direction path, and the second region is located on the right side of the first direction path; in the second first-type pixel region, the first region is located on the right side of the first direction path, and the second region is located on the left side of the first direction path. Of course, other symmetrical design schemes about the first direction path are also feasible, and no further restrictions are imposed on them.

[0108] The first reset tube M21 in the first reset section 113 is disposed in the first direction channel. In this embodiment, the first reset tube M21 is disposed in the first direction channel below the overlapping area.

[0109] The first source follower tube M31 in the first readout section 114 is disposed at the overlapping region, and the first selection tube M41 in the first readout section 114 is disposed in the first direction channel. In this embodiment, the first selection tube M41 is disposed in the first direction channel above the overlapping region. As an optional solution, the first reset tube M21 and the first selection tube M41 are symmetrically disposed in the first direction channels on both sides of the first source follower tube M31, and their positions can be adjusted according to actual needs.

[0110] The first gain transistor M51 in the first gain section 115 is disposed in the second direction channel. In this embodiment, the first gain transistor M51 is disposed in the second direction channel on the left side of the overlapping region.

[0111] The first overflow tube M61 in the first overflow section 116 is disposed in the second direction channel. In this embodiment, the first overflow tube M61 is disposed in the second direction channel on the right side of the overlapping region. When both the first gain section 115 and the first overflow section 116 are included, the first gain tube M51 and the first overflow tube M61 are symmetrically disposed in the second direction channels on both sides of the first source follower tube M31; in practical applications, the positions of the two can be adjusted according to actual needs, and the corresponding information can be found in [reference needed]. Figure 6 The pixel circuit shown.

[0112] The first floating diffusion region FD1 is at least disposed in the second region, and is disposed in the second directional channel near the overlapping region. When the first floating diffusion region FD1 is a complete node, the first floating diffusion region FD1 is disposed in the second directional channel of the second region near the overlapping region, for example, disposed in the second directional channel between the first source follower M31 and the first overflow tube M61. When the first floating diffusion region FD1 includes two nodes that are separate from each other, the first floating diffusion node FD11 is disposed in the second directional channel of the first region near the overlapping region, for example, disposed in the second directional channel between the first source follower M31 and the first gain tube M51, and the second floating diffusion node FD12 is disposed in the second directional channel of the second region near the overlapping region, for example, disposed in the second directional channel between the first source follower M31 and the first overflow tube M61; as an optional solution, the two floating diffusion nodes are symmetrically disposed in the second directional channels on both sides of the overlapping region. In one implementation, when the first floating diffusion region FD1 includes a first floating diffusion node FD11 and a second floating diffusion node FD12, the first floating diffusion node FD11 simultaneously serves as the first end of the corresponding first transmission tube M11, and similarly, the first floating diffusion node FD12 simultaneously serves as the first end of the corresponding second transmission tube M12. Figure 10 As shown.

[0113] Regarding the two floating diffusion nodes mentioned above: when the first overflow portion 116 is not included, the two floating diffusion nodes can be electrically isolated from each other or electrically interconnected, and in the corresponding application, they have no effect on the exposure of the second photosensitive portion 112; when the first overflow portion 116 is included, the two floating diffusion nodes are electrically isolated from each other to avoid affecting the overflow charge generated by the second photosensitive portion 112 during exposure. In practical applications, the devices in the first type of pixel area are electrically interconnected through metal interconnects. For example, the first floating diffusion node FD11 is coupled to the power supply potential AVDD through a metal interconnect, and the second floating diffusion node FD12 is coupled to at least the control terminal of the first source follower transistor M31 in the first readout portion 114 through a metal interconnect.

[0114] like Figure 11 As shown, the second type of pixel area includes a first region and a second region, as indicated by the dashed boxes on the left and right sides of the figure, respectively. The first region and the second region are symmetrically arranged on both sides of the first directional channel. Furthermore, the first region and the second region are also symmetrically arranged along the second directional channel. The first directional channel and the second directional channel intersect and have an overlapping area; for example, the first directional channel and the second directional channel are perpendicular to each other and have this overlapping area. In this embodiment, the first directional channel is a vertical channel, and the second directional channel is a horizontal channel.

[0115] The device arrangement of the third photosensitive element PD13 and the third transmission tube M13 in the third photosensitive unit 121 is the same as that of the first photosensitive element PD11 and the first transmission tube M11 in the first photosensitive unit 111; the device arrangement of the fourth photosensitive element PD14 and the fourth transmission tube M14 in the fourth photosensitive unit 122 is the same as that of the second photosensitive element PD12 and the second transmission tube M12 in the second photosensitive unit 112; the device arrangement of the second reset tube M22 in the second reset unit 123 is the same as that of the first reset tube M21 in the first reset unit 113. The device arrangement of the second source follower transistor M32 and the second selector transistor M42 in the second readout section 124 is the same as that of the first source follower transistor M31 and the first selector transistor M41 in the first readout section 114; the device arrangement of the second gain transistor M52 in the second gain section 125 is the same as that of the first gain transistor M51 in the first gain section 115; the device arrangement of the second overflow transistor M62 in the second overflow section 126 is the same as that of the first overflow transistor M61 in the first overflow section 116; the specific device arrangement can be found above, and will not be repeated here.

[0116] Regarding the second floating diffusion region FD2: When the second floating diffusion region FD2 is a complete node, it can be located in the second directional channel of the first region near the overlapping region, for example, in the second directional channel between the second source follower M32 and the second gain tube M52; or it can be located in the second directional channel of the second region near the overlapping region, for example, in the second directional channel between the second source follower M32 and the second overflow tube M62. When the second floating diffusion region FD2 includes two nodes that are separate from each other, the third floating diffusion node FD21 is located in the second directional channel of the first region near the overlapping region, for example, in the second directional channel between the second source follower M32 and the second gain tube M52; the fourth floating diffusion node FD22 is located in the second directional channel of the second region near the overlapping region, for example, in the second directional channel between the second source follower M32 and the second overflow tube M62; as an optional solution, the two floating diffusion nodes are symmetrically located in the second directional channels on both sides of the overlapping region. In one implementation, when the second floating diffusion region FD2 includes a third floating diffusion node FD21 and a fourth floating diffusion node FD22, the third floating diffusion node FD21 simultaneously serves as the first end of the corresponding third transmission tube M13. Similarly, the fourth floating diffusion node FD22 simultaneously serves as the first end of the corresponding fourth transmission tube M14. Figure 11As shown. Furthermore, the third floating diffusion node FD21 and the fourth floating diffusion node FD22 are electrically interconnected. In practical applications, the devices in the second type of pixel region are electrically interconnected via metal interconnects. For example, the third floating diffusion node FD21 and the fourth floating diffusion node FD22 are at least coupled to the control terminal of the second source follower transistor M32 in the second readout section 124 via metal interconnects.

[0117] It should be noted that this embodiment only shows the layout design of each photosensitive element and each transistor, and does not show the layout design of each overflow capacitor; in actual applications, each photosensitive element and each transistor is disposed in the same metal layer, and each overflow capacitor is disposed in another metal layer, and the layout design of each overflow capacitor has no substantial impact on this embodiment.

[0118] When the first type of pixel unit 110 includes a first gain unit 115, in one implementation, such as Figure 12 As shown, an isolation portion is formed between the first gain transistor M51 and the first floating diffusion node FD11, and the first gain transistor M51 and the second floating diffusion node FD12 are electrically interconnected. The isolation portion can be formed by doping in the substrate, for example, P-type doping to form an isolation structure, a shallow trench isolation structure (STI), or by spacing it at a distance or other methods, to facilitate the first gain transistor M51's signal acquisition by the second photosensitive unit 112. When the second type of pixel unit 120 includes a second gain portion 125, in one implementation, as shown... Figure 13 As shown, no isolation section is provided between the second gain transistor M52 and the second floating diffusion region FD2 (e.g., with the third floating diffusion node FD21 in the second floating diffusion region FD2). Instead, the electrical interconnection of the circuit is directly achieved through doping sharing, for example, N-doping. This method facilitates the execution of corresponding operations by different types of pixel units in the entire pixel array.

[0119] In one implementation, such as Figure 12 and Figure 13 As shown, a wiring method is also provided. In the first type of pixel unit 110, as... Figure 12 As shown, the first transmission transistor M11 and the first floating diffusion node FD11 are electrically interconnected through the metal interconnects of the first metal wiring layer L1. The first source follower transistor M31 and the second floating diffusion node FD12 are also electrically interconnected through the metal interconnects of the first metal wiring layer L1. Simultaneously, the second floating diffusion node FD12 and the corresponding first gain transistor M51 are electrically interconnected through the metal interconnects of the second metal wiring layer L2. Achieving these electrical connections through wiring in different layers is beneficial for optimizing electrical performance and improving wiring flexibility. In the second type of pixel unit 120, as... Figure 13As shown, the third floating diffusion node FD21 and the fourth floating diffusion node FD22 are electrically interconnected with the second source follower transistor M32 through the metal interconnects of the first metal wiring layer L1. In practical applications, the first metal wiring layer L1 and the second metal wiring layer L2 are different wiring layers in the image sensor. In one example, the first metal wiring layer L1 is located between the semiconductor substrate and the second metal wiring layer L2.

[0120] This embodiment also provides a phase focusing method for an image sensor 100, including the following steps; wherein the image sensor 100 is implemented using the circuit structure described above in this embodiment.

[0121] The specific method includes: coupling the control terminal and the first terminal of the first transmission tube M11 in the first photosensitive unit 111 to the power supply potential AVDD, and using the photosensitive structure formed by the second photosensitive unit 112 to perform phase difference detection, so as to realize phase detection autofocus (PDAF).

[0122] In the first photosensitive section 111, the control terminal and the first terminal of the first transmission tube M11 are simultaneously coupled to the power supply voltage AVDD, so as to use the power supply potential AVDD to clear the charge on the first photosensitive element PD11, thereby realizing the formation of a non-photosensitive signal structure in the first photosensitive section 111 without the aid of a light shield; since no light shield is used, the influence between adjacent pixels can be avoided.

[0123] In the second photosensitive unit 112, the control terminal of the second transmission tube M12 receives the first transmission control signal TX1, and the first terminal of the second transmission tube M12 is coupled to the first floating diffusion region FD1. At this time, the second photosensitive unit 112 forms a photosensitive structure as a normal pixel (also called a normal pixel) to obtain the first side pixel signal, and together with the second side pixel signal obtained by another second photosensitive unit 112 in the phase focusing pixel pair, it serves as the focusing information to realize phase difference detection.

[0124] In one implementation, at least the second photosensitive unit 112 in the first type of pixel unit 110 is used to convert the light signal into a first charge signal and a second charge signal. The second charge signal overflows from the second photosensitive unit 112 based on the first floating diffusion region FD1, and phase focusing is achieved at least based on the second charge signal. In practical applications, the first charge signal refers to the charge signal corresponding to the potential well portion, and the second charge signal refers to the charge signal corresponding to the overflow portion after the charge exceeds the potential well. When the amount of charge sensed by the corresponding photosensitive unit has not reached the overflow state, the converted charge signal only includes the first charge signal and is stored in the corresponding photosensitive unit; at this time, the second charge signal can be considered zero. When the amount of charge sensed by the corresponding photosensitive unit reaches the overflow state, the converted charge signal includes both the first and second charge signals. The first charge signal is stored in the corresponding photosensitive unit, and the second charge signal overflows from the corresponding photosensitive unit and is stored in the corresponding overflow portion. Of course, in some other applications, the first charge signal can also be defined as the potential well charge signal, and the second charge signal can be defined as the overflow or spillover charge signal.

[0125] In this embodiment, for the first type of pixel unit 110, the first photosensitive part 111 does not generate a photosensitive signal, while the second photosensitive part 112 normally senses light and transfers charge to the first floating diffusion region FD1 to form a first-side pixel signal, which is then quantized and read out by the first readout part 114. Furthermore, the first reset part 113, the first gain part 115, and the first overflow part 116 all operate normally. The first reset part 113 is used to reset at least the first floating diffusion region FD1, the first gain part 115 is used to switch between different conversion gains, and the first overflow part 116 is used to store the overflow charge from the second photosensitive part 112 to form an overflow signal. For the second type of pixel unit 120, all parts operate normally, and will not be described further here.

[0126] During phase focusing, with Figure 10 Taking the layout shown as an example, the right-side pixel signal (e.g., overflow signal) is acquired as partial focus information, i.e., Right-PDAF. The first floating diffusion area FD1 includes two independent and electrically isolated floating diffusion nodes: a first floating diffusion node FD11 on the left and a second floating diffusion node FD12 on the right. The right-side pixel signal undergoes subsequent readout quantization through the second floating diffusion node FD12 to acquire partial focus information. Through the design of these two floating diffusion nodes, separate control and signal isolation of the first photosensitive unit 111 and the second photosensitive unit 112 can be achieved. Electrical control of the first photosensitive unit 111 does not affect the signal acquisition of the second photosensitive unit 112. This not only improves the focusing accuracy of LOFIC pixels but also enhances the flexibility of the layout design.

[0127] In summary, the image sensor and its arrangement structure of this invention separates a photosensitive part into independent first and second photosensitive parts. The control terminal and first terminal of the first transmission tube in the first photosensitive part are coupled to a power supply potential to clear the charge on the first photosensitive element. Without the aid of a light-blocking plate, the first photosensitive part forms a non-photosensitive structure, while the second photosensitive part forms a photosensitive structure as a normal pixel, thereby achieving phase detection autofocus. Since this invention eliminates the need for a light-blocking plate during phase detection autofocus, it avoids interference between adjacent pixels, thus reducing errors and improving accuracy. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial applicability.

[0128] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. An image sensor, characterized in that, Including the first type of pixel unit, wherein: The first type of pixel unit includes a first photosensitive part, a second photosensitive part, and a first floating diffusion region; The first photosensitive part includes a first photosensitive element and a first transmission tube, wherein the control terminal and the first terminal of the first transmission tube are coupled to a power supply potential, and the second terminal of the first transmission tube is coupled to a reference potential via the first photosensitive element. The second photosensitive part includes a second photosensitive element and a second transmission tube, wherein the control terminal of the second transmission tube receives a first transmission control signal, the first end of the second transmission tube is coupled to the first floating diffusion region, and the second end of the second transmission tube is coupled to a reference potential via the second photosensitive element.

2. The image sensor according to claim 1, characterized in that, The first type of pixel unit includes a first reset part and a first readout part, or the first type of pixel unit further includes a first gain part; The first reset unit includes a first reset transistor, wherein the control terminal of the first reset transistor receives a first reset control signal, the first terminal of the first reset transistor is coupled to a power supply potential, and the second terminal of the first reset transistor is coupled to the first floating diffusion region. The first readout unit includes a first source follower transistor (RST) and a first select transistor. The control terminal of the first RST is coupled to the first floating diffusion region, the first terminal of the first RST is coupled to a variable potential, the second terminal of the first RST is coupled to the first terminal of the first select transistor, the control terminal of the first select transistor receives a first select control signal, and the second terminal of the first select transistor is coupled to the corresponding column line. When a first gain section is included, the first gain section includes a first gain transistor, wherein the control terminal of the first gain transistor receives a first gain control signal, and the first and second ends of the first gain transistor are coupled between the second end of the first reset transistor and the first floating diffusion region; or, the first end of the first gain transistor is coupled to the first floating diffusion region, and the second end of the first gain transistor is coupled to a reference potential via a first gain capacitor.

3. The image sensor according to claim 1 or 2, characterized in that, The control terminal and the first terminal of the first transmission tube are also coupled to the first floating diffusion region.

4. The image sensor according to claim 3, characterized in that, The first floating diffusion region includes a first floating diffusion node and a second floating diffusion node, which are set separately from each other; wherein, the control end and the first end of the first transmission tube are coupled to the first floating diffusion node, or the first floating diffusion node serves as the first end of the first transmission tube and the control end of the first transmission tube is coupled to the first floating diffusion node, and the first end of the second transmission tube is coupled to the second floating diffusion node.

5. The image sensor according to claim 2, characterized in that, The first type of pixel unit further includes a first overflow portion; The first overflow section includes a first overflow tube and a first overflow capacitor, wherein the control terminal of the first overflow tube receives a first overflow control signal, the first end of the first overflow tube is coupled to the first floating diffusion region, and the second end of the first overflow tube is coupled to a reference potential via the first overflow capacitor. Alternatively, when the first type of pixel unit includes a first gain section and the first end and the second end of the first gain transistor are coupled between the second end of the first reset transistor and the first floating diffusion region, the first end of the first overflow transistor is coupled to the first floating diffusion region and the second end of the first gain transistor is coupled to the first floating diffusion region; or, the first end of the first overflow transistor is changed from being coupled to the first floating diffusion region to being coupled to the first end of the first gain transistor. Alternatively, when the first type of pixel unit includes a first gain section and the second end of the first gain transistor is coupled to the first floating diffusion region and the first end of the first gain transistor is coupled to a reference potential through a first gain capacitor, the first end of the first overflow transistor is coupled to the first floating diffusion region.

6. The image sensor according to claim 5, characterized in that, The first floating diffusion region includes a first floating diffusion node and a second floating diffusion node, which are separately arranged and electrically isolated from each other; wherein, the control end and the first end of the first transmission tube are coupled to the first floating diffusion node, or the first floating diffusion node serves as the first end of the first transmission tube and the control end of the first transmission tube is coupled to the first floating diffusion node, and the first end of the second transmission tube is coupled to the second floating diffusion node.

7. The image sensor according to claim 1, characterized in that, The number of the first type of pixel units includes at least two, wherein the two first type of pixel units form a phase focusing pixel pair; in the two different first type of pixel units corresponding to the phase focusing pixel pair, the two second photosensitive parts are arranged opposite each other to detect the phase difference.

8. The image sensor according to claim 1, 2, or 5, characterized in that, It also includes a second type of pixel unit, wherein: The second type of pixel unit includes a third photosensitive part, a fourth photosensitive part, and a second floating diffusion region; the interconnection method of the corresponding transmission tube and the corresponding photosensitive element in the third photosensitive part and the fourth photosensitive part is the same as that in the second photosensitive part; the second floating diffusion region includes a third floating diffusion node and a fourth floating diffusion node that are separately arranged, and the two floating diffusion nodes are electrically interconnected with each other. Alternatively, the second type of pixel unit may further include a second reset section and a second readout section; the interconnection method of the second reset transistor in the second reset section is the same as that of the first reset section, and the interconnection method of the second source follower transistor and the second select transistor in the second readout section is the same as that of the first readout section.

9. The image sensor according to claim 8, characterized in that, The second type of pixel unit further includes a second gain section and / or a second overflow section; the interconnection method of the second gain transistor in the second gain section is the same as that of the first gain section, and the interconnection method of the second overflow transistor and the second overflow capacitor in the second overflow section is the same as that of the first overflow section.

10. An image sensor arrangement structure as described in any one of claims 1 to 9, characterized in that, include: The first type of pixel area includes a first region and a second region, which are symmetrically arranged on both sides of the first direction path, wherein the first direction path and the second direction path are intersected and have an overlapping area. A first photosensitive element is disposed in the first region, and a second photosensitive element is disposed in the second region, wherein a first transmission tube is disposed at least at the corner of the first photosensitive element near the overlapping region, and a second transmission tube is disposed at least at the corner of the second photosensitive element near the overlapping region; The first floating diffusion zone is at least disposed in the second region, and is disposed in the second direction channel near the overlapping region.

11. The image sensor arrangement structure according to claim 10, characterized in that, When the first reset section and the first readout section are included, the first source follower tube is disposed at the overlapping area, the first reset tube and the first selection tube are disposed in the first direction channel, and are symmetrically disposed on both sides of the first source follower tube. When a first gain section is also included, the first gain tube is disposed in the second direction channel; When a first overflow portion is also included, the first overflow pipe is disposed in the second direction channel; When the first gain section and the first overflow section are also included, the first gain tube and the first overflow tube are disposed in the second direction channel and are symmetrically disposed on both sides of the first source follower tube.

12. The image sensor arrangement structure according to claim 10 or 11, characterized in that, The first floating diffusion zone includes a first floating diffusion node and a second floating diffusion node. The first floating diffusion node is disposed in the second direction channel of the first region, and the second floating diffusion node is disposed in the second direction channel of the second region. Furthermore, the first floating diffusion node and the second floating diffusion node are symmetrically disposed on both sides of the overlapping region.

13. The image sensor arrangement structure according to claim 12, characterized in that, When the first overflow portion is not included, the first floating diffusion node and the second floating diffusion node are electrically isolated from each other or electrically interconnected. When the first overflow portion is included, the first floating diffusion node and the second floating diffusion node are electrically isolated from each other. And / or, when the first gain portion is also included, an isolation portion is formed between the first gain transistor in the first gain portion and the first floating diffusion node, and the second floating diffusion node is electrically interconnected with the first gain transistor. And / or, when the first gain portion and the first readout portion are also included, the first transmission transistor and the first floating diffusion node are electrically interconnected through the metal interconnects of the first metal wiring layer, the first source follower transistor in the first readout portion is electrically interconnected with the second floating diffusion node through the metal interconnects of the first metal wiring layer, and the second floating diffusion node is electrically interconnected with the corresponding first gain transistor through the metal interconnects of the second metal wiring layer.

14. The image sensor arrangement structure according to claim 10 or 11, characterized in that, Also includes: The second type of pixel region has the same device arrangement as the first type of pixel region; wherein, when the second floating diffusion region includes a third floating diffusion node and a fourth floating diffusion node, the two floating diffusion nodes are electrically interconnected with each other.

15. The image sensor arrangement structure according to claim 14, characterized in that, When a second gain section is also included, the second gain section and the second floating diffusion region are electrically interconnected directly through doping sharing; and / or, the third floating diffusion node and the fourth floating diffusion node are electrically interconnected with the second source follower in the second readout section through the metal interconnects of the first metal wiring layer.

Images