Image sensor and electronic device

Abstract

The utility model discloses an image sensor and an electronic device, the image sensor is provided with a pixel area, a peripheral logic area located at the periphery of the pixel area and a transition area located between the pixel area and the peripheral logic area, a first metal grating is arranged in the pixel area, a peripheral shading metal block is arranged in the peripheral logic area, and a second metal grating is arranged in the transition area. The transition area is provided with a stress blocking structure or / and a stress gradual change structure, the stress blocking structure is used for blocking stress between the first metal grating and the peripheral shading metal block, and the stress of the stress gradual change structure is gradually increased from the first metal grating to the peripheral shading metal block. According to the application, the transition region is arranged between the pixel region and the peripheral logic region, and the stress blocking structure or / and the stress gradual change structure is arranged in the transition region, so that the stress between the first metal grating and the peripheral shading metal block is blocked or gradually changed; the influence of the stress difference of the peripheral shading metal blocks in the peripheral logic region on the first metal grating in the pixel region is avoided or reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of image sensors, in particular to an image sensor and electronic equipment. Background Art

[0002] In the camera module, the image sensor is the core component, which determines the imaging quality of the camera and the structure and specifications of other components, and accounts for about 52% of the cost of the camera module. The image sensor is a semiconductor device that can convert optical images into electrical signals. Image sensors can be roughly divided into charge coupled devices (CCD) and complementary metal oxide semiconductor image sensors (CMOS Image Sensor, CIS). Among them, the CCD image sensor is integrated on the single crystal silicon material, and the pixel signal moves row by row and column by column and is amplified at the edge exit position. The advantages of the CCD image sensor are high image sensitivity and low noise, but the integration of the CCD image sensor with other devices is difficult, and the power consumption of the CCD image sensor is high. Among them, the CMOS image sensor is integrated on the metal oxide semiconductor material, and each pixel point is equipped with a signal amplifier, and the pixel signal can be directly scanned and exported. In contrast, the CMOS image sensor has the advantages of simple process, easy integration with other devices, small size, light weight, low power consumption, and low cost, and gradually replaces the position of CCD. At present, CMOS image sensors are widely used in digital cameras, camera phones, digital video cameras, medical imaging devices (such as gastroscopes), automotive imaging devices and other fields.

[0003] Image sensors can be divided into front-illuminated and back-illuminated (BSI) image sensors according to the different paths of incident light entering the photodiode. Front-illuminated refers to an image sensor in which the incident light enters the photodiode from the side close to the circuit connection layer, while back-illuminated refers to an image sensor in which the incident light enters the photodiode from the side away from the circuit connection layer. In order to increase the area of ​​the photodiode in the image sensor and reduce the loss of incident light in the dielectric layer, we can use the back-illuminated image sensor process, that is, the incident light enters the photodiode from the back of the silicon wafer, thereby reducing the loss of incident light in the dielectric layer and improving the sensitivity of the pixel unit.

[0004] like Figure 1As shown, in the prior art, whether it is a front-illuminated image sensor or a back-illuminated image sensor, both include a pixel area and a peripheral logic area located around the pixel area. For an image sensor, the characteristics of the pixel area used for photosensitivity directly determine the performance of the final image sensor. The pixel area needs to use a metal grid 12 to prevent crosstalk between pixels, and the peripheral logic area needs a light-shielding metal block 11 to shield the incident light. In the prior art, the light-shielding metal block 11 and the metal grid 12 are made of the same metal layer. The light-shielding metal block 11 and the metal grid 12 are tightly connected, that is, each grid line is connected to the light-shielding metal block 11. The disadvantage of this is that there is a stress difference between the light-shielding metal block 11 and the metal grid 12, so that the pixel array close to the light-shielding metal block 11 will be affected, resulting in the pixel array close to the light-shielding metal block 11. There is a difference in center and edge imaging (shading) in the image when there is no light, so as to affect the final imaging quality. Utility Model Content

[0005] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide an image sensor and an electronic device to solve the problem in the prior art that the pixel array close to the light-shielding metal block is affected by stress differences.

[0006] The purpose of the utility model is achieved through the following technical solutions:

[0007] The utility model provides an image sensor, the image sensor comprising a pixel area, a peripheral logic area located outside the pixel area, and a transition area located between the pixel area and the peripheral logic area, wherein:

[0008] A first metal grid is provided in the pixel area, a peripheral light-shielding metal block is provided in the peripheral logic area, and a stress blocking structure and / or a stress gradient structure is provided in the transition area. The stress blocking structure is used to block the stress between the first metal grid and the peripheral light-shielding metal block, and the stress of the stress gradient structure gradually increases from the first metal grid toward the peripheral light-shielding metal block.

[0009] Optionally, the stress blocking structure comprises a gap for spacing the first metal grid and the peripheral light-shielding metal block apart from each other.

[0010] Optionally, metal connecting wires are provided in the transition area, the number of the metal connecting wires is less than the number of grid lines in the first metal grid, one end of the metal connecting wire is connected to the first metal grid, and the other end is connected to the peripheral shading metal block.

[0011] Optionally, the metal connection line is arranged in a corner area of ​​the transition zone; and / or the metal connection line is arranged in a side area of ​​the transition zone.

[0012] Optionally, the first metal grid, the metal connecting wires and the peripheral light-shielding metal block are all formed based on the same metal layer.

[0013] Optionally, the stress gradient structure includes a second metal grid, in which the width of the grid lines in the second metal grid gradually increases from the first metal grid toward the peripheral shading metal block, or the metal filling factor of the corresponding grid unit in the second metal grid gradually increases from the first metal grid toward the peripheral shading metal block.

[0014] Optionally, the stress gradient structure includes a second metal grid, in which the density of grid lines gradually increases from the first metal grid toward the peripheral shading metal block, or the density and width of the grid lines gradually increase from the first metal grid toward the peripheral shading metal block.

[0015] Optionally, the transverse grid lines in the left / right side regions of the transition zone are distributed at equal intervals, and the longitudinal grid lines in the upper / lower side regions of the transition zone are distributed at equal intervals.

[0016] Optionally, the density of transverse grid lines in the left / right side area of ​​the transition zone is the same as the density of transverse grid lines in the first metal grid, and the density of longitudinal grid lines in the upper / lower side area of ​​the transition zone is the same as the density of longitudinal grid lines in the first metal grid.

[0017] Optionally, the density of the horizontal grid lines in the left / right side area of ​​the transition zone gradually increases from the middle of the left / right side area toward the corner area of ​​the transition zone, and the density of the vertical grid lines in the upper / lower side area of ​​the transition zone gradually increases from the middle of the upper / lower side area toward the corner area of ​​the transition zone.

[0018] Optionally, the first metal grid, the second metal grid and the peripheral light-shielding metal block are all formed by the same metal layer.

[0019] Optionally, a virtual pixel area is further provided between the transition area and the peripheral logic area; and / or a virtual pixel unit is provided in the semiconductor substrate corresponding to the transition area, and the virtual pixel unit corresponds to the pixel unit of the pixel area.

[0020] The present application also provides an electronic device, which includes the image sensor as described above.

[0021] The beneficial effects of the utility model are as follows: the present application sets a transition zone between the pixel area and the peripheral logic area, and a stress blocking structure and / or a stress gradient structure is provided in the transition zone, thereby blocking or gradiently changing the stress between the first metal grid and the peripheral shading metal block, so as to avoid or reduce the influence of the stress difference of the peripheral shading metal block in the peripheral logic area on the first metal grid in the pixel area, thereby reducing the stress difference between the center and the edge of the first metal grid, reducing the difference between the center and the edge of the pixel array caused by this, alleviating the problem that the image of the pixel array will produce center and edge imaging difference (shading) when there is no light, and can further improve the photosensitivity of the pixel array, improve the photosensitivity consistency of the pixel array, and enhance the image quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the planar structure of an image sensor in the prior art;

[0023] Figure 2 This is the basic circuit diagram of the image sensor;

[0024] Figure 3 This is a basic connection diagram of transistors in an image sensor;

[0025] Figure 4 This is one of the schematic diagrams of the planar structure of the image sensor in the first embodiment of the present utility model;

[0026] Figure 5 This is the second schematic diagram of the planar structure of the image sensor in the first embodiment of the utility model;

[0027] Figure 6 It is a schematic diagram of the planar structure of the image sensor in the second embodiment of the utility model;

[0028] Figure 7 This is one of the planar structural schematic diagrams of the image sensor in the third embodiment of the present utility model;

[0029] Figure 8 This is the second schematic diagram of the planar structure of the image sensor in the third embodiment of the present utility model;

[0030] Fig. 9 This is one of the planar structural schematic diagrams of the image sensor in the fourth embodiment of the present utility model;

[0031] Fig.10 This is the second schematic diagram of the planar structure of the image sensor in the fourth embodiment of the present utility model. DETAILED DESCRIPTION

[0032] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the present invention, the specific implementation methods, structures, features and effects of the image sensor and electronic device proposed by the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments:

[0033] Figure 2 This is the basic circuit diagram of the image sensor. Figure 2 As shown, the image sensor 100 includes a read circuit 104 and a control circuit 108 connected to a pixel array 102, a functional logic circuit 106 connected to the read circuit 104, and performs logic control on the reading of the pixel circuit; the read circuit 104 and the control circuit 108 are connected to a state register 112 to implement the reading control of the pixel array 102. The pixel array 101 includes a plurality of pixel units in rows (R1, R2, R3 ... Ry) and columns (C1, C2, C3 ... Cx), and the pixel signals output by the pixel array 102 are output to the read circuit 104 via column lines.

[0034] In one embodiment, after each pixel unit acquires image data, the image data is read out through the readout circuit 104 using the readout mode specified by the status register 112, and then transmitted to the functional logic circuit 106. In a specific application, the readout circuit 104 may include an analog-to-digital conversion (ADC) circuit, an amplification circuit, and others. In some application embodiments, the status register 112 may include a programmed selection system to determine whether the readout system is read out through a rolling exposure mode (rolling shutter) or a global exposure mode (global shutter). The functional logic circuit 106 may only store image data or image data applied or processed with image effects. In one application example, the readout circuit 104 may read out column lines (such as Figure 2 ) to read out image data one row at a time, or various other methods may be used to read out image data. The operation of the control circuit 108 may be determined by the current setting of the status register 112. For example, the control circuit 108 generates a shutter signal for controlling image acquisition. In some application examples, the shutter signal may be a global exposure signal so that all pixels of the pixel array 102 simultaneously acquire their image data through a single acquisition window. In some other application examples, the shutter signal may be a rolling exposure signal, and each pixel row is continuously read through the acquisition window.

[0035] Figure 3 This is a connection diagram of a transistor in an image sensor. Figure 3As shown, each sensor pixel circuit 200 includes a light sensing element 210 (e.g., a photodiode) and a pixel support circuit 211. The photodiode 210 may be a buried photodiode used in current image sensors. In one embodiment, the pixel support circuit 211 includes a reset transistor (RST) 220, a source follower (SF) transistor 225, and a row select transistor (RS) 230, connected to a transfer transistor (TX) 215 and the photodiode 210 as shown in the figure. In another embodiment, not shown, the pixel support circuit 211 includes a reset transistor 220, a source follower transistor 225, and a row select transistor 230 disposed on a circuit chip, and connected to the photodiode 210 in another chip based on the transfer transistor 215. During operation, the light sensing element 210 generates photocharges in response to incident light during exposure. The transfer transistor 215 is connected to a transfer signal, which controls the transfer transistor 215 to transfer the charge accumulated in the photodiode 210 to the floating diffusion region (FD) 217. In one embodiment, reset transistor 220 is connected between VDD and floating diffusion region 217, and responds to reset signal RST to reset sensor pixel circuit 200 (e.g., discharge or charge floating diffusion region 217 and photodiode 210 to a current voltage). Floating diffusion region 217 is connected to the gate of source follower transistor 225. Source follower transistor 225 is connected between VDD and row select transistor 230, and responds to the potential of floating diffusion FD region 217 and outputs it. Row select transistor 230 connects the pixel circuit output from source follower transistor 225 to a readout column, or bit line 235, in response to a row select control signal.

[0036] [Example 1]

[0037] Figure 4 This is one of the planar structural schematic diagrams of the image sensor in the first embodiment of the utility model. Figure 5 This is the second schematic diagram of the planar structure of the image sensor in the first embodiment of the present utility model. Figure 4 and Figure 5 As shown, an image sensor provided by the first embodiment of the present invention comprises a pixel region, a peripheral logic region located outside the pixel region, and a transition region located between the pixel region and the peripheral logic region.

[0038] in:

[0039] A first metal grid 32 is provided in the pixel area, a peripheral shading metal block 31 is provided in the peripheral logic area, and a stress blocking structure and / or a stress gradient structure is provided in the transition area. The stress blocking structure is used to block the stress between the first metal grid 32 and the peripheral shading metal block 31. The stress of the stress gradient structure gradually increases from the first metal grid 32 toward the peripheral shading metal block 31.

[0040] The present application sets a transition zone between the pixel area and the peripheral logic area, and a stress blocking structure and / or a stress gradient structure are provided in the transition zone, so as to block or gradient the stress between the first metal grid 32 and the peripheral shading metal block 31, so as to avoid or reduce the influence of the stress difference of the peripheral shading metal block 31 in the peripheral logic area on the first metal grid 32 in the pixel area, thereby reducing the stress difference between the center and edge of the first metal grid 32, reducing the difference between the center and edge of the pixel array caused by this, alleviating the problem of center and edge imaging difference (shading) of the pixel array in the absence of light, and further improving the photosensitivity.

[0041] In this embodiment, a stress blocking structure is provided in the transition region, and the stress blocking structure is used to block the stress between the first metal grid 32 and the peripheral light-shielding metal block 31 .

[0042] In one example, if Figure 5 As shown, the stress blocking structure includes a gap 33, which is used to separate the first metal grid 32 and the peripheral light-shielding metal block 31 from each other, so as to block the stress between the first metal grid 32 and the peripheral light-shielding metal block 31. Since the stress blocking structure (gap 33) is provided in the transition zone to block the stress between the first metal grid 32 and the peripheral light-shielding metal block 31, the number of dummy pixel units (dummy pixel) can be greatly reduced, and further, the width of the gap 33 can be made relatively small, so that the chip size can be reduced and the cost can be reduced. Among them, the width of the gap 33 can be set according to the actual situation or the manufacturing process accuracy. Since the gap 33 only needs to disconnect the first metal grid 32 and the peripheral light-shielding metal block 31 from each other, the stress interference between the first metal grid 32 and the peripheral light-shielding metal block 31 can be blocked. Therefore, the smaller the width of the gap 33, the better. In addition, it should be noted that the dummy pixel unit (dummy pixel) here can be a dummy pixel set in the image sensor in the prior art, which can be configured as a clamping circuit, sacrifice or used to relieve stress. Based on the design of the present application, the stress impact between the pixel area and the peripheral logic area is improved by means of a stress blocking structure and / or a stress gradient structure, and the size of the virtual pixel area can be reduced. For example, when the same stress relief and clamping circuit functions are achieved, the sum of the area corresponding to the virtual pixel unit and the area of ​​the transition zone of the present design is smaller than the area of ​​the existing design using only the virtual pixel unit.

[0043] In one example, the pixel area is a rectangular structure, and a pixel array is arranged in the pixel area. The peripheral logic area is a rectangular frame structure and surrounds the periphery of the pixel area, that is, the light shielding metal block is also a rectangular frame structure and surrounds the periphery of the first metal grid 32; the transition area is a rectangular frame structure and is arranged between the pixel area and the peripheral logic area, that is, the gap 33 is a rectangular frame structure and is arranged between the light shielding metal block and the first metal grid 32.

[0044] In one example, the first metal grid 32 and the peripheral light shielding metal block 31 are both formed based on the same metal layer, that is, the first metal grid 32 and the peripheral light shielding metal block 31 are etched from the same metal layer through the same mask process. The metal layer is, for example, tungsten, aluminum, copper, or other metals.

[0045] In one example, a virtual pixel area is further provided between the transition area and the peripheral logic area, and a virtual pixel unit (dummy pixel) is provided in the virtual pixel area. Furthermore, a peripheral light-shielding metal block 31 is also provided on the virtual pixel area to simultaneously realize light shielding of the virtual pixel area based on the peripheral light-shielding metal block 31. The pixel structure in the virtual pixel unit can be consistent with the pixel structure of the pixel unit in the pixel array, or it can be an additionally provided pixel structure to meet the needs of practical applications.

[0046] In another example, a virtual pixel area is also provided between the pixel area and the transition area, and a virtual pixel unit (dummy pixel) is provided in the virtual pixel area. Furthermore, a first metal grid 32 is also provided on the virtual pixel area, so as to configure a grid structure on the virtual pixel area based on the first metal grid 32. Among them, the pixel structure in the virtual pixel unit can be consistent with the pixel structure of the pixel unit in the pixel array, or it can be an additionally provided pixel structure to meet the needs of practical applications. Among them, in this example, the virtual pixel unit (dummy pixel) provided in the virtual pixel area can be consistent with the pixel unit arrangement of the pixel area, for example, the pixel circuit is consistent, the layout is consistent, the device structure is consistent, etc. This is conducive to the matching of the virtual pixel area with the pixel area and the realization of the existing virtual pixel application, and can also be conducive to the reduction of the entire area corresponding to the existing virtual pixel area design method.

[0047] In another example, a dummy pixel unit is provided in the semiconductor substrate corresponding to the transition region. Further, the dummy pixel unit is provided with neither a first metal grid 32 nor a peripheral light-shielding metal block 31, but a correspondingly configured gap 33. The pixel structure in the dummy pixel unit may be consistent with the pixel structure of the pixel unit in the pixel array, or may be an additionally provided pixel structure to meet the needs of practical applications.

[0048] [Example 2]

[0049] Figure 6 FIG. 1 is a schematic diagram of the planar structure of the image sensor in the second embodiment of the present utility model. Figure 6 As shown, the image sensor provided by the second embodiment of the present invention is the same as that provided by the first embodiment ( Figure 4 and Figure 5 ) are substantially the same, except that, in this embodiment:

[0050] Metal connecting wires 331 are provided in the transition region, and the number of metal connecting wires 331 is less than the number of grid lines in the first metal grid 32. Furthermore, the number of metal connecting wires 331 arranged on the same side of the corresponding pixel array may be less than the number of grid lines arranged. One end of the metal connecting wire 331 is connected to the first metal grid 32, and the other end is connected to the peripheral light-shielding metal block 31. Since the gap 33 disconnects the first metal grid 32 and the peripheral light-shielding metal block 31 from each other, the contact between the first metal grid 32 and the semiconductor substrate is limited, and the first metal grid 32 is suspended, which may cause the floating charge in some processes to be unable to be derived. The metal connecting wires 331 are provided to connect the first metal grid 32 with the peripheral light-shielding metal block 31, which can be conducive to the derivation of floating charges, and can also improve the stability of the first metal grid 32 based on the connection method. Among them, the number of metal connecting wires 331 cannot be set to be too large. If more metal connecting wires 331 are set, the stress interference between the first metal grid 32 and the peripheral light-shielding metal block 31 will increase.

[0051] In one example, if Figure 6 As shown, the number of metal connection lines 331 is 4, which are arranged in the corner area of ​​the transition zone, so as to connect the first metal grid 32 with the peripheral light-shielding metal block 31 in the corner area, and the two sides corresponding to the pixel array share one metal connection line. Of course, in other embodiments, the metal connection lines 331 can also be arranged in the side area of ​​the transition zone; or, arranged in the corner area and the side area of ​​the transition zone. Among them, the line width of the metal connection line 331 can be set according to actual conditions. Under the condition of ensuring the connection strength, the smaller the line width of the metal connection line 331, the better. The smaller the line width of the metal connection line 331, the smaller the stress interference between the first metal grid 32 and the peripheral light-shielding metal block 31.

[0052] In one example, the first metal grid 32, the metal connection line 331 and the peripheral light shielding metal block 31 are all formed based on the same metal layer, that is, the first metal grid 32, the metal connection line 331 and the peripheral light shielding metal block 31 are etched from the same metal layer through the same mask process. The metal layer is, for example, tungsten, aluminum, copper or other metals.

[0053] It should be understood by those skilled in the art that the rest of the structure and working principle of this embodiment are the same as those of the first embodiment and will not be described in detail here.

[0054] [Example 3]

[0055] Figure 7 This is one of the planar structural schematic diagrams of the image sensor in the third embodiment of the present utility model. Figure 8 This is the second schematic diagram of the planar structure of the image sensor in the third embodiment of the present utility model. Figure 7 and Figure 8 As shown, a third embodiment of the present invention provides an image sensor, which comprises a pixel region, a peripheral logic region located outside the pixel region, and a transition region located between the pixel region and the peripheral logic region.

[0056] in:

[0057] A first metal grid 32 is provided in the pixel area, a peripheral shading metal block 31 is provided in the peripheral logic area, and a stress blocking structure and / or a stress gradient structure is provided in the transition area. The stress blocking structure is used to block the stress between the first metal grid 32 and the peripheral shading metal block 31. The stress of the stress gradient structure gradually increases from the first metal grid 32 toward the peripheral shading metal block 31.

[0058] The present application sets a transition zone between the pixel area and the peripheral logic area, and a stress blocking structure or / and a stress gradient structure are provided in the transition zone, so as to block or gradient the stress between the first metal grid 32 and the peripheral light-shielding metal block 31, so as to avoid or reduce the influence of the stress difference of the peripheral light-shielding metal block 31 in the peripheral logic area on the first metal grid 32 in the pixel area, thereby reducing the stress difference between the center and the edge of the first metal grid 32, reducing the difference between the center and the edge of the pixel array caused by this, alleviating the problem of the center and edge imaging difference (shading) of the pixel array in the absence of light, and further improving the photosensitivity. In addition, since a stress gradient structure (second metal grid 34) is provided in the transition zone to gradiently change the stress between the first metal grid 32 and the peripheral light-shielding metal block 31, the number of dummy pixels can be greatly reduced, and further, the size of the second metal grid 34 can be made relatively small, thereby reducing the chip size and reducing the cost.

[0059] In this embodiment, the transition zone is provided with a stress gradient structure, and the stress of the stress gradient structure gradually increases from the first metal grid 32 toward the peripheral light-shielding metal block 31. Of course, in other embodiments, the transition zone may also be provided with a stress blocking structure and a stress gradient structure at the same time, thereby further reducing the stress interference between the first metal grid 32 and the peripheral light-shielding metal block 31.

[0060] In one example, if Figure 7 and Figure 8 As shown, the stress gradient structure includes a second metal grid 34, in which the density of grid lines gradually increases from the first metal grid 32 toward the peripheral light-shielding metal block 31, so that the stress magnitude in the transition zone gradually increases from the first metal grid 32 toward the peripheral light-shielding metal block 31, so as to reduce the stress interference between the first metal grid 32 and the peripheral light-shielding metal block 31. In one example, the second metal grid 34 in the transition zone is composed of horizontal grid lines and vertical grid lines intersecting each other, such as Figure 7 As shown, therefore, it can be considered that the density of grid lines in the corner area of ​​the transition area is greater than the density of grid lines in the upper / lower / left / right side areas of the transition area.

[0061] Among them, the inner edge of the second metal grid 34 is connected to the first metal grid 32, and the outer edge is connected to the peripheral shading metal block 31. The first metal grid 32 is connected to the peripheral shading metal block 31 through the second metal grid 34, which can further improve the stability of the first metal grid 32 on the semiconductor substrate.

[0062] In one example, if Figure 7 As shown, the horizontal grid lines in the left / right side regions of the transition region are distributed at equal intervals, and the vertical grid lines in the upper / lower side regions of the transition region are distributed at equal intervals. The density of the transverse grid lines in the left / right side areas of the transition zone is the same as the density of the transverse grid lines in the first metal grid 32, that is, the transverse grid lines in the left / right side areas of the transition zone are connected to the transverse grid lines in the first metal grid 32 as a straight line, thereby increasing the connection strength with the first metal grid 32 and simplifying the process implementation of the second metal grid 34, wherein the density of the longitudinal grid lines in the left / right side areas of the transition zone gradually increases from the first metal grid 32 toward the peripheral shading metal block 31; the density of the longitudinal grid lines in the upper / lower side areas of the transition zone is the same as the density of the longitudinal grid lines in the first metal grid 32, that is, the longitudinal grid lines in the upper / lower side areas of the transition zone are connected to the longitudinal grid lines in the first metal grid 32 as a straight line, thereby increasing the connection strength with the first metal grid 32 and simplifying the process implementation of the second metal grid 34, wherein the density of the transverse grid lines in the upper / lower side areas of the transition zone gradually increases from the first metal grid 32 toward the peripheral shading metal block 31.

[0063] In another example, if Figure 8As shown, the density of the horizontal grid lines in the left / right side area of ​​the transition area gradually increases from the middle of the left / right side area toward the corner area of ​​the transition area; the density of the vertical grid lines in the upper / lower side area of ​​the transition area gradually increases from the middle of the upper / lower side area toward the corner area of ​​the transition area, that is, the stress magnitude of the transition area gradually increases from the middle of the side area toward the corner area. Because the stress of the corner area in the transition area is greatly affected by the stress of the corner area in the peripheral shading metal block 31, the density of the grid lines in the corner area of ​​the transition area is set to be larger, which can reduce the stress difference between the middle and corner areas.

[0064] In one example, the first metal grid 32, the second metal grid 34 and the peripheral light shielding metal block 31 are all formed by the same metal layer. That is, the first metal grid 32, the second metal grid 34 and the peripheral light shielding metal block 31 are etched from the same metal layer through the same mask process. The metal layer is, for example, tungsten, aluminum, copper or other metals.

[0065] In one example, a dummy pixel area is further provided between the transition area and the peripheral logic area, and a dummy pixel unit (dummy pixel) is provided in the dummy pixel area. And / or, a dummy pixel area is further provided between the pixel area and the transition area, and a dummy pixel unit is provided in the dummy pixel area. And / or, a dummy pixel area is provided in the semiconductor substrate corresponding to the transition area, and a dummy pixel unit (dummy pixel) is provided in the dummy pixel area.

[0066] [Example 4]

[0067] Fig. 9 This is one of the planar structural schematic diagrams of the image sensor in the fourth embodiment of the present utility model. Fig.10 This is the second schematic diagram of the planar structure of the image sensor in the fourth embodiment of the present utility model. Fig. 9 and Fig.10 As shown, the image sensor provided by the fourth embodiment of the present invention is the same as that provided by the third embodiment ( Figure 7 and Figure 8 ) are substantially the same, except that, in this embodiment:

[0068] The width of the grid lines in the second metal grid 34 gradually increases from the first metal grid 32 toward the peripheral light-shielding metal block 31, or the metal filling factor of the corresponding grid unit in the second metal grid 34 gradually increases from the first metal grid 32 toward the peripheral light-shielding metal block 31, so that the stress magnitude of the transition zone gradually increases from the first metal grid 32 toward the peripheral light-shielding metal block 31, so as to reduce the stress interference between the first metal grid 32 and the peripheral light-shielding metal block 31. Of course, in other embodiments, the density and width of the grid lines in the second metal grid 34 may also gradually increase from the first metal grid 32 toward the peripheral light-shielding metal block 31.

[0069] In one example, if Fig. 9 As shown, the grid lines of the second metal grid 34 are connected to the grid lines of the first metal grid 32 in the same straight line, thereby increasing the connection strength with the first metal grid 32 , but there is a certain difference in the opening area of ​​the grid in the same circle of the second metal grid 34 .

[0070] In another example, if Fig.10 As shown, the opening areas of the grids in the same circle of the second metal grid 34 are the same, and the opening areas of the grids in the second metal grid 34 gradually decrease from the first metal grid 32 toward the peripheral light-shielding metal block 31 .

[0071] It should be understood by those skilled in the art that the rest of the structure and working principle of this embodiment are the same as those of the third embodiment, and will not be described in detail here.

[0072] The utility model also provides an electronic device, including an image sensor as described in any one of the above schemes. For the electronic device of the utility model, for example, it can be a vehicle-mounted device, which includes an image sensor. The specific structure of the image sensor refers to the above embodiment. Since the vehicle-mounted device includes the technical solution of the above embodiment, it at least has all the beneficial effects brought by the technical solution of the above embodiment, which will not be repeated here. Of course, the electronic device provided by the utility model can also be monitoring equipment, machine vision, drones, mobile phones, cameras, etc.

[0073] In this document, the directional words such as up, down, left, right, front, and back are defined by the positions of the structures in the drawings and the positions of the structures relative to each other, just for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of the directional words should not limit the scope of protection claimed in this application. It should also be understood that the terms "first" and "second" used in this document are only used to distinguish names and are not used to limit quantity and order.

[0074] The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the profession can make some changes or modifications to the technical contents disclosed above without departing from the scope of the technical solution of the present invention, which are equivalent embodiments of equivalent changes. However, any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. An image sensor, characterized in that: The image sensor comprises a pixel region, a peripheral logic region located at the periphery of the pixel region, and a transition region located between the pixel region and the peripheral logic region, wherein: A first metal grid is provided in the pixel area, a peripheral light-shielding metal block is provided in the peripheral logic area, and a stress blocking structure and / or a stress gradient structure is provided in the transition area. The stress blocking structure is used to block the stress between the first metal grid and the peripheral light-shielding metal block, and the stress of the stress gradient structure gradually increases from the first metal grid toward the peripheral light-shielding metal block.

2. The image sensor according to claim 1, characterized in that The stress blocking structure includes a gap for spacing the first metal grid and the peripheral light-shielding metal block apart from each other.

3. The image sensor according to claim 2, characterized in that Metal connecting wires are arranged in the transition area, the number of the metal connecting wires is less than the number of grid lines in the first metal grid, one end of the metal connecting wire is connected to the first metal grid, and the other end is connected to the peripheral shading metal block.

4. The image sensor according to claim 3, characterized in that: The metal connection line is arranged in a corner area of ​​the transition area; and / or the metal connection line is arranged in a side area of ​​the transition area.

5. The image sensor according to claim 3 or 4, characterized in that: The first metal grid, the metal connection line and the peripheral light-shielding metal block are all formed based on the same metal layer.

6. The image sensor according to claim 1, characterized in that: The stress gradient structure includes a second metal grid, in which the width of the grid lines in the second metal grid gradually increases from the first metal grid toward the peripheral shading metal block, or the metal filling factor of the corresponding grid unit in the second metal grid gradually increases from the first metal grid toward the peripheral shading metal block.

7. The image sensor according to claim 1, characterized in that: The stress gradient structure includes a second metal grid, in which the density of grid lines gradually increases from the first metal grid toward the peripheral shading metal block, or the density and width of the grid lines gradually increase from the first metal grid toward the peripheral shading metal block.

8. The image sensor according to claim 7, characterized in that: The horizontal grid lines in the left / right side area of ​​the transition zone are distributed at equal intervals, and the vertical grid lines in the upper / lower side area of ​​the transition zone are distributed at equal intervals; and / or, the density of the vertical grid lines in the left / right side area of ​​the transition zone gradually increases from the first metal grid toward the peripheral shading metal block, and the density of the horizontal grid lines in the upper / lower side area of ​​the transition zone gradually increases from the first metal grid toward the peripheral shading metal block.

9. The image sensor according to claim 8, characterized in that: The density of transverse grid lines in the left / right side regions of the transition zone is the same as that of the transverse grid lines in the first metal grid, and the density of longitudinal grid lines in the upper / lower side regions of the transition zone is the same as that of the longitudinal grid lines in the first metal grid.

10. The image sensor according to claim 7, characterized in that: The density of the horizontal grid lines in the left / right side area of ​​the transition zone gradually increases from the middle of the left / right side area toward the corner area of ​​the transition zone, and the density of the vertical grid lines in the upper / lower side area of ​​the transition zone gradually increases from the middle of the upper / lower side area toward the corner area of ​​the transition zone.

11. The image sensor according to any one of claims 6 to 10, characterized in that: The first metal grid, the second metal grid and the peripheral light-shielding metal block are all formed by the same metal layer.

12. The image sensor according to claim 1, characterized in that: A virtual pixel area is also arranged between the transition area and the peripheral logic area; and / or, a virtual pixel area is also arranged between the pixel area and the transition area; and / or, a virtual pixel unit is provided in the semiconductor substrate corresponding to the transition area, and the virtual pixel unit corresponds to the pixel unit of the pixel area.

13. An electronic device, characterized in that: The electronic device comprises the image sensor as claimed in any one of claims 1-12.

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