Solid-state imaging device and method of making solid-state imaging device
The design of a solid-state imaging device with uniformly doped conductive structures between a photodiode, transfer gate, and floating diffusion improves charge transfer and reduces overlay errors, addressing low full well capacity and image lag issues.
Patent Information
- Application Number
- PCT/CN2024/089621
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-04-24
- Publication Date
- 2025-10-30
AI Technical Summary
The reduction of pixel size in solid-state imaging devices leads to low full well capacity and is exacerbated by overlay errors and critical dimension fluctuations during silicon processing, which affect charge transfer capability and image lag.
A solid-state imaging device design that connects a first photodiode, transfer gate, and floating diffusion through conductive structures with uniformly doped ions, allowing for improved charge transfer capacity and reduced impact from overlay errors and critical dimension fluctuations.
Enhances charge transfer capacity and reduces image lag by tolerating large preparation errors and maintaining pixel performance, such as full well capacity and blooming control.
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Figure CN2024089621_30102025_PF_FP_ABST
Abstract
Description
SOLID-STATE IMAGING DEVICE AND METHOD OF MAKING SOLID-STATE IMAGING DEVICETECHNICAL FIELD
[0001] Embodiments of the present application relate to the field of electronic devices, and more particularly, to a solid-state imaging device, a method of making a solid-state imaging device, and an electronic device.BACKGROUND
[0002] A solid-state imaging device is used to convert optical signals into electrical signals. The solid-state imaging device includes a pixel array, which includes multiple pixels. To reduce the size of the solid-state imaging device, it is necessary to reduce the size of each pixel in the pixel array. However, the reduction of the size of each pixel in the pixel array causes the low full well capacity (FWC) . A deep photodiode (PD) can be utilized to enhance FWC. The deep PD means the PD is set closer to the substrate. However, this deep PD needs a high charge transfer capability of a charge transfer path, which is a path through a transfer gate (TX) from the PD to a floating diffusion (FD) . Meanwhile, the PD and the TX have an overlay error and critical dimension (CD) fluctuation during silicon processing, which leads to a large image lag.
[0003] Therefore, how to improve the charge transfer capacity and reduce the impact of overlay error and CD fluctuation during silicon processing is a challenge.SUMMARY
[0004] Embodiments of the present application provide a solid-state imaging device, a method of making a solid-state imaging device, and an electronic device. The technical solution improves a charge transfer capacity and reduces an impact of overlay error and CD fluctuation during silicon processing.
[0005] According to a first aspect, an embodiment of this application provides a solid-state imaging device. The solid-state imaging device includes: a substrate, a first photodiode (PD) , a transfer gate (TX) , a floating diffusion (FD) , a first conductive structure and a second conductive structure; the first PD is disposed on an upper portion of the substrate; the TX, the FD, the first conductive structure, and the second conductive structure are disposed on the first PD, or, the TX, the FD, the first conductive structure, and the second conductive structure are disposed between the substrate and the first PD; the FD is disposed on one side of a first direction of the TX, where the first direction is parallel to an upper surface of the substrate; the first conductive structure is disposed on a side of the TX away from the FD, where the first conductive structure is connected to the first PD and the TX; and the second conductive structure is disposed between the TX and the FD, where the second conductive structure is connected to the TX and the FD, and types of ions doped in the first PD, the first conductive structure, and the second conductive structure are the same.
[0006] According to the method above, the first PD, the TX and the FD are connected through the first conductive structure and the second conductive structure, and types of ions doped in the first PD, the first conductive structure, and the second conductive structure are the same, thereby improving the charge transfer capacity from the first PD to the FD and reducing the impact of overlay error and CD fluctuation during silicon processing.
[0007] In a possible design, the first conductive structure is connected to the second conductive structure.
[0008] According to the method above, when the first conductive structure and the second conductive are connected, they can be considered as one conductive structure. In other words, the first PD, the TX and the FD are connected through a conductive structure, and types of ions doped in the first PD and the conductive structure are the same, thereby improving the charge transfer capacity from the first PD to the FD and reducing the impact of overlay error and CD fluctuation during silicon processing.
[0009] In a possible design, the first conductive structure is a second photodiode.
[0010] According to the method above, the first conductive structure includes the second material, and types of ions doped in the first PD and the second material are the same. Alternatively, the first conductive structure is a PD with the same type of ions doped in the first PD.
[0011] In a possible design, the first conductive structure includes a first part far from the TX and a second part near the TX, the first part and the second part of the first conductive structure have a same width in a second direction, or, the first part and the second part of the first conductive structure have different widths in a second direction, the second direction is parallel to the upper surface of the substrate, and the second direction is perpendicular to the first direction; and / or the second conductive structure includes a first part near the TX and a second part near the FD, the first part and the second part of the second conductive structure have a same width in a second direction, or, the first part and the second part of the second conductive structure have different widths in a second direction.
[0012] In a possible design, the first conductive structure includes a first part far from the TX and a second part near the TX, the first part and the second part of the first conductive structure have a same width in a third direction, or, the first part and the second part of the first conductive structure have different widths in a third direction, the third direction is perpendicular to the upper surface of the substrate; and / or the second conductive structure includes a first part near the TX and a second part near the FD, the first part and the second part of the second conductive structure have a same width in a third direction, or, the first part and the second part of the second conductive structure have different widths in a third direction.
[0013] In a possible design, the first conductive structure and the second conductive structure have different widths in a second direction and / or a third direction, the second direction is parallel to the upper surface of the substrate, the second direction is perpendicular to the first direction, and the third direction is perpendicular to the first direction and the second direction.
[0014] According to the method above, the shape of the first conductive structure and / or the second conductive structure is flexibly adjusted, so that the first conductive structure and / or the second conductive structure have a large error margin during silicon processing, which tolerates large preparation errors.
[0015] In a possible design, an orthographic projection area of the TX on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the first conductive structure on the upper surface of the substrate; and / or an orthographic projection area of the TX on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the second conductive structure on the upper surface of the substrate.
[0016] In a possible design, an orthographic projection area of the FD on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the second conductive structure on the upper surface of the substrate.
[0017] According to the method above, the positions of the TX, the first conductive structure, and the second conductive structure in the first direction and / or the second direction are flexibly adjusted, while the positions of the FD and the second conductive structure in the first direction and / or the second direction are flexibly adjusted. Therefore, the solid-state imaging device is robust against the overlay error and CD fluctuation during silicon processing, thereby reducing the image lag.
[0018] In a possible design, a first distance and a second distance are different, the first distance is a distance between a first surface of the first conductive structure and the upper surface of the substrate, the first surface of the first conductive structure is a surface of the first conductive structure near the first PD, the second distance is a distance between a first surface of the second conductive structure and the upper surface of the substrate, and the first surface of the second conductive structure is a surface of the second conductive structure near the first PD.
[0019] In a possible design, a third distance and a fourth distance are different, the third distance is a distance between a second surface of the first conductive structure and the upper surface of the substrate, the second surface of the first conductive structure is a surface of the first conductive structure away from the first PD, the fourth distance is a distance between a second surface of the second conductive structure and the upper surface of the substrate, and the second surface of the second conductive structure is a surface of the second conductive structure away from the first PD.
[0020] In a possible design, a second distance and a fifth distance are different, the second distance is a distance between a first surface of the second conductive structure and the upper surface of the substrate, the first surface of the second conductive structure is a surface of the second conductive structure near the first PD, the fifth distance is a distance between a first surface of the FD and the upper surface of the substrate, and the first surface of the FD is a surface of the FD near the first PD.
[0021] According to the method above, the distance between the first conductive structure and the substrate and the distance between the second conductive structure and the substrate are different, and the distance between the FD and the substrate and the distance between the second conductive structure and the substrate are the same. In other words, the first conductive structure and the second conductive structure have different depths in the solid-state imaging device, and the second conductive structure and the FD have the same depth in the solid-state imaging device, so that the photoelectron charges smoothly pass through the first conductive structure, the TX, and the second conductive structure from the PD to the FD, thereby improving the charge transfer capacity of the solid-state imaging device.
[0022] In a possible design, the solid-state imaging device also includes a first material layer, the first material layer is disposed on a side of the first conductive structure away from the first PD, the types of ions doped in the first PD and the first material layer are different, or, ions are not doped in the first material layer; and / or, the first material layer is disposed on a side of the first conductive structure and the second conductive structure away from the first PD.
[0023] According to the method above, the types of ions doped in the first PD and the FD are same, and the types of ions doped in the first material layer and the FD are different, thereby avoiding interference with the FD and avoiding affecting the performance of the solid-state imaging device.
[0024] In a possible design, the TX includes a protruded portion and at least one embedded portion, each embedded portion is disposed between the protruded portion and the first PD, and an angle is formed between each embedded portion and the protruded portion.
[0025] In a possible design, the TX includes embedded portions, at least two embedded portions of the TX have different sizes and / or shapes.
[0026] According to the method above, the shape of the TX is flexibly adjusted, thereby improving flexibility in the layout design of the solid-state imaging device, and keeping basic pixel performance, such as FWC, lag, and blooming.
[0027] In a possible design, an orthographic projection area of the protruded portion on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the first conductive structure on the upper surface of the substrate; and / or, the orthographic projection area of the protruded portion on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the second conductive structure on the upper surface of the substrate.
[0028] According to the method above, the positions of the protruded portion in the TX, the first conductive structure, and the second conductive structure in the first direction and / or the second direction are flexibly adjusted, and thus the solid-state imaging device is robust against the overlay error and CD fluctuation during silicon processing, thereby reducing the image lag.
[0029] In a possible design, the solid-state imaging device also includes a first material layer, the first material layer is disposed between the first conductive structure and the protruded portion, the types of ions doped in the first PD and the first material layer are different, or, ions are not doped in the first material layer; and / or, the first material layer is disposed between the first conductive structure and the protruded portion, as well as between the second conductive structure and the protruded portion.
[0030] In a possible design, an orthographic projection area of the protruded portion on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the first material layer on the upper surface of the substrate.
[0031] According to the method above, the existence of the first material layer avoids interference with the FD and avoids affecting the performance of the solid-state imaging device.
[0032] In a possible design, a blooming path is controlled by a bias of the TX, the blooming path is a charge transfer path starting from the first PD and sequentially passing through the first conductive structure, the TX, and the second conductive structure to the FD, the bias of the TX is a voltage greater than or equal to -2 volt (V) , and the bias of the TX is a voltage less than or equal to +1 V during an exposure.
[0033] According to the method above, the bias voltage of TX controls the blooming path in the solid-state imaging device, thereby flexibly adjusting the anti-blooming capability of the solid-state imaging device and reducing fluctuations of the anti-blooming capability.
[0034] According to a second aspect, an embodiment of this application provides a method of making a solid-state imaging device. This method includes: forming a substrate; and forming a first photodiode (PD) , a transfer gate (TX) , a floating diffusion (FD) , a first conductive structure and a second conductive structure on the substrate, to form a solid-state imaging device in any one of the first aspect or any possible design of the first aspect.
[0035] According to a third aspect, an embodiment of this application provides a solid-state imaging device, which includes: a solid-state imaging device in any one of the first aspect or any possible design of the first aspect, a control circuit and a signal processing circuit, where the control circuit is configured to control the pixel array in the solid-state imaging device, and the signal processing circuit is configured to process image data obtained from the solid-state imaging device.
[0036] According to a fourth aspect, an embodiment of this application provides an electronic device, which includes: a solid-state imaging device in the third aspect.DESCRIPTION OF DRAWINGS
[0037] FIG. 1 is an example block diagram of an imaging system.
[0038] FIG. 2 is an example circuit diagram of an imaging device.
[0039] FIG. 3 is an example block diagram of a backside illuminated solid-state imaging device.
[0040] FIG. 4 is an example block diagram of a frontside illuminated solid-state imaging device.
[0041] FIG. 5 is an example block diagram of a solid-state imaging device according to an embodiment of this application.
[0042] FIG. 6 is an example block diagram of a solid-state imaging device according to an embodiment of this application.
[0043] FIG. 7 is an example block diagram of a backside illuminated solid-state imaging device according to an embodiment of this application.
[0044] FIG. 8 is an example block diagram of a frontside illuminated solid-state imaging device according to an embodiment of this application.
[0045] FIG. 9 is an example block diagram of a solid-state imaging device according to an embodiment of this application.
[0046] FIG. 10 is an example block diagram of a solid-state imaging device according to an embodiment of this application.
[0047] FIG. 11 is an example block diagram of a solid-state imaging device according to an embodiment of this application.
[0048] FIG. 12 is an example block diagram of a solid-state imaging device according to an embodiment of this application.
[0049] FIG. 13 is an example block diagram of a solid-state imaging device according to an embodiment of this application.
[0050] FIG. 14 is an example block diagram of a solid-state imaging device according to an embodiment of this application.
[0051] FIG. 15 is an example block diagram of a solid-state imaging system according to an embodiment of this application.
[0052] FIG. 16 is a schematic diagram of a method of making a solid-state imaging device according to an embodiment of this application.
[0053] FIG. 17 shows the application fields of the solid-state imaging device according to an embodiment of this application.
[0054] FIG. 18 shows an example of the application of the solid-state imaging device in a car according to an embodiment of this application.DESCRIPTION OF EMBODIMENTS
[0055] The following describes the technical solutions in the present application with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without making creative labor shall fall within the scope of protection of the present application.
[0056] The present application will present aspects, embodiments, or features around systems that include multiple devices, components, modules, etc. It should be understood and appreciated that the individual systems may include additional devices, components, modules, etc., and / or may not include all of the devices, components, modules, etc. discussed in connection with the accompanying drawings. In addition, combinations of these options may be used.
[0057] In addition, in the embodiments of the present application, the word “exemplarily” and the phrase “as an example” are used to indicate for example, illustration or description. Any embodiment or design solution described as “exemplarily” in this application should not be construed as being superior to or more advantageous than other embodiments or design solutions. Rather, the use of the word “example” is intended to present the concept in a specific manner.
[0058] The phrases “in some possible embodiments” , “in some possible application scenarios” , etc., appearing in various places in this description, do not necessarily refer to the same embodiments, but rather mean “one or more, but not all, embodiments” unless otherwise specifically emphasized. Unless otherwise specifically emphasized, the terms “including” , “comprising” , “having” , and variations thereof all mean “including but not limited to” .
[0059] In the present application, “at least one” refers to one or more, and “multiple” refers to two or more. “and / or” , describing the association of the associated objects, indicates that three relationships can exist. For example, A and / or B can mean A alone, both A and B, and B alone, where A and B can be singular or plural. The character “ / ” generally indicates that the preceding and following associated objects are in an “or” relationship.
[0060] The application scenarios described in the present application embodiments are intended to illustrate the technical solutions of the present application embodiments more clearly and do not constitute a limitation to the technical solutions provided by the present application embodiments. It is known to those of ordinary skill in the art that the technical solutions provided by the present application embodiments are equally applicable to similar technical problems as the system architecture evolves and new application scenarios emerge.
[0061] The solid-state imaging device in the embodiments of the present application is applied to an imaging system, as well as various electronic devices including the imaging system, such as cameras, digital cameras, video cameras, mobile phones, smartphones, game consoles, pads, wearable cameras, medical devices (such as endoscopes) , cosmetic equipment, vehicles or transport equipment such as trucks, farmland cameras, home appliances such as televisions and refrigerators, etc. The solid-state imaging device in the embodiments of the present application converts incident electromagnetic waves into pixel charges. The solid-state imaging device in the embodiments of the present application is a frontside illuminated solid-state imaging device or a backside illuminated solid-state imaging device.
[0062] FIG. 1 is an example block diagram of an imaging system. An imaging system 100 in FIG. 1 includes: a pixel array 110, a control circuit 120, a readout circuit 130 and a signal processing circuit 140. The pixel array is a two-dimensional array of pixels. Each pixel may be an imaging device as shown in FIG. 3-FIG. 15. The pixels are arranged in rows (R1 to Ry) and columns (C1 to Cx) to obtain image data of a subject. The control circuit controls the pixel array, for example, generates a shutter signal. The image data is readout by the readout circuit 130 and sent to the signal processing circuit 140. The signal processing circuit 140 obtains and processes the image data.
[0063] FIG. 2 is an example circuit diagram of an imaging device. An imaging device in FIG. 2 includes pixels, and each pixel includes at least one PD and at least one TX.
[0064] A PD converts an electromagnetic wave into an electrical charge. The electrical charge is selectively transmitted to a FD via a TX. The FD is connected to a gate of an amplifier device (AMP) , and an output signal (Vout) is transmitted to a signal line via a row select device (SEL) . A current source (Icolumn) is connected between the SEL and the ground. Accordingly, if gates of the TX and the SEL are turned on, the output signal corresponding to the electrical signal from the PD is obtained on the signal line. A reset device (RST) selectively resets an electrical charge accumulated in the FD. A dual conversion gain device (DCG) may be connected between the RST and the FD, or may be connected between AVDD1 and the FD, in order to realize high dynamic range by combining two types of gains. AVDD1 and AVDD2 are positive power sources for analog power supply, and used for power supply. AVSS1 can be a ground or negative voltage in the range of -5.0 V to 0 V.
[0065] In some embodiments, a signal is obtained by carrying out a correlating double sampling (CDS) , which reduces fixed pattern noise and reset noise by using a difference between a reset level and a signal level.
[0066] In some embodiments, charge voltage conversion is done by the AMP using source follower (SF) operation with a gain of equal to unity or less than unity. In some embodiments, charge voltage conversion is done by the AMP with gain of greater than unity, where a differential amplification mode can be adopted, for instance.
[0067] In some embodiments, focus detecting pixels as well as imaging pixels are implemented in the pixel array. In order to perform an auto focus function, a unit pixel may include at least two photoelectric conversion units, such as PDs.
[0068] In some embodiments, the pixel device including RST, DCG, SEL, and AMP may be shared by at least two PDs.
[0069] In some embodiments, Vout may be more than two, and at least two rows are read simultaneously.
[0070] In some embodiments, PD is made of n-type doping and pixel to pixel isolation is made of p-type doping. Alternatively, PD is made of p-type doping and pixel to pixel isolation is made of n-type doping. The p-type doping is acheived of doping the trivalent elements (such as aluminum, boron, etc. ) to semiconductor materials. The n-type doping is acheived by doping the pentavalent elements (such as phosphorus, arsenic, etc. ) to semiconductor materials.
[0071] In some embodiments, AVDD1 and AVDD2 are the same.
[0072] In some embodiments, AVSS1 and AVSS2 are the same.
[0073] In some embodiments, some of RST, DCG, AMP, SEL, TX can be positive channel metal oxide semiconductor (PMOS) .
[0074] In some embodiments, pixel isolation may be acheived by a shallow trench isolation (STI) , or doping isolation.
[0075] In some embodiments, some of RST, DCG, AMP, or SEL can be made from different wafers and bonded together with a wafer that includes PD, TX, and FD.
[0076] The imaging device in FIG. 2 reads out data on a frame-by-frame basis composed of all of the pixels in the array by sequentially reading out the pixel charges stored in all of the pixels in the array by using the RST. However, alternatively, instead of reading out data on the frame-by-frame basis, an imaging device operating in a way referred to as an event driven type can be embodied by using the pixel of the embodiment of the present application. In the event driven imaging device, data can be output asynchronously and at any time in response to changes in the intensity of the electromagnetic wave incident on the pixel. Specifically, for example, when the pixel charges generated by the electromagnetic wave incident on the pixel and stored in the pixel exceeds a predetermined threshold, data can be output to indicate that the intensity of the electromagnetic wave exceeds a threshold value or the intensity of the electromagnetic wave, in combination with coordinates and time information of the pixel.
[0077] In some embodiments, the pixel has a so-called global shutter scheme, and the imaging device has an all pixel simultaneous electronic shutter function by voltage domain or charge domain.
[0078] In some embodiments, a large capacitor, for example, which is made of a positive-negative junction (PN) capacitor, a metal oxide semiconductor (MOS) capacitor, a metal-oxide-metal (MOM) capacitor, a metal-insulator-metal (MIM) capacitor, a polysilicon-insulator-polysilicon (PIP) capacitor, a dynamic random access memory (DRAM) , a magnetoresistive random access memory (MRAM) , other types of on-chip memory, or combinations thereof, electrically connects to the node between DCG drain and RST source. In the high-illuminance mode, the floating diffusion area is electrically connected to the above-mentioned capacitor. For example, in the high-illuminance mode, overflowed charges from the photodiode are not drained and are instead held by using an expanded FWC. The expanded FWC may make a potential change of the FD area relatively small compared to the amount of overflowed charges. For example, a conversion gain becomes small in the high-illuminance mode. This is accomplished by activating the DCG control signal to be provided to the solid-state imaging device such that the DCG transistor is turned on. In this case, the DCG transistor may always be maintained in a turn-on state while an operation is performed in the high-illuminance mode.
[0079] FIG. 3 is an example block diagram of a backside illuminated solid-state imaging device. The backside illuminated solid-state imaging device in FIG. 3 includes: a substrate 310, a first metal wiring layer 320, a pixel array 330, a color filter layer 340 and a microlens layer 350.
[0080] The substrate 310 is disposed on the bottom layer. The substrate 310 includes a semiconductor material such as silicon or germanium. In some embodiments, the substrate 310 includes at least one or more of other photosensitive materials, such as silicon germanium, silicon carbide, gallium arsenide, gallium phosphide, indium gallium arsenide, indium phosphide, indium arsenide, indium antimonide, semiconductor on insulator or combinations thereof.
[0081] The first metal wiring layer 320 is disposed on an upper portion of the substrate 310. The first metal wiring layer 320 includes at least one metal structure, such as metal wire or metal block. The first metal wiring layer 320 also includes medium material, and the specific type of this medium material is not limited in the embodiments of the present application. The first metal wiring layer 320 may include, for example, the readout circuit 130 and / or the signal processing circuit 140 as shown in FIG. 1.
[0082] The pixel array 330 is disposed on the first metal wiring layer 320. In other words, the first metal wiring layer 320 is disposed between the substrate 310 and the pixel array 330. The pixel array 330 includes a first medium layer and PDs. The first medium layer includes the first medium, at least one metal structure 311 and at least one TX. The first medium, for example, is an oxide, and the specific type of the first medium is not limited in the embodiments of the present application. The metal structure is metal wire or metal block, and the metal structure is connected with the lower surface of the TX. The lower surface of the TX is a surface of the TX near the substrate 310. The first medium layer is isolated from the PD by the second medium structure and the third medium structure. The types of ions doped in the PD and the second medium structure are different. The types of ions doped in the PD and the third medium structure are different. The types of ions doped in the second medium structure and the third medium structure are different or the same. For example, the PD is made of n-type doping, the second medium structure includes p+ type doping, and the third medium structure is made of p-type doping. The concentration of ions in p+ type doping is higher than the concentration of ions in p-type doping. The second medium structure is disposed on one side of a first direction of the third medium structure, the first direction is parallel to an upper surface of the substrate 310. The upper surface of the substrate 310 is a surface of substrate 410 near the PD. The FD is disposed in the third medium structure, and the FD includes n+ type doping. The concentration of ions in n+ type doping is higher than the concentration of ions in n-type doping.
[0083] Adjacent PDs in pixel array 330 are isolated by the third medium structure and a fourth medium structure. The types of ions doped in the PD and the fourth medium structure are different. Or, the concentration of ions doped in the fourth medium structure and the PD are different. Or, the fourth medium structure is non-doping. The third medium structure is disposed between the second medium structure and the fourth medium structure. And / or, the third medium structure is disposed between the first medium structure and the PD. The third medium structure includes the third medium, and the fourth medium structure includes the fourth medium. The third medium and the fourth medium are different or the same, which is not limited in the embodiments of the present application. The pixel array 330 also includes deep trench isolation (DTI) . The lower surface of the DTI also includes a raised structure along the fourth direction. The lower surface of the DTI is a surface of the DTI near the substrate 310. The fourth direction is from the microlens layer 350 to the substrate 310. The fourth direction is opposite to the third direction. The raised structure of the DTI is disposed in the fourth medium structure. The fourth medium structure is used to isolate the adjacent PDs. The raised structure of the DTI is isolated from the fourth medium structure by the fifth medium.
[0084] In some embodiments, the fifth medium is an oxide, and the specific type of the fifth medium is not limited in the embodiments of the present application. For example, the fifth medium is one of SiO2, SiN, SiON, HfO2, Al2O3, ZrO2, Ta2O5, TiO2, La2O3, Pr2O3, CeO2, Nd2O3, Pm2O3, Sm2O3, Eu2O3, Gd2O3, Tb2O3, Dy2O3, Ho2O3, Er2O3, Tm2O3, Yb2O3, Lu2O3, Y2O3 or its combination.
[0085] In some embodiments, the TX is a vertical transfer gate (VTG) to improve the charge transfer capability of the TX. The VTG includes a protruded portion and at least one embedded portion. The protruded portion of the VTG is disposed in the first medium layer, and each embedded portion of the VTG is perpendicular to the protruded portion of the VTG. The VTG structure has a variant, such as a tapered VTG, shallow a reverse tapered VTG, a slanted VTG, a bottom corner rounded VTG, a top corner rounded VTG. These have the advantage of further increasing pixel charge transfer capability.
[0086] In some embodiments, photosensitive substrate structure has a variant, such as proximate steep structures, small cone structures, multiple four-sided pyramid structures, and single four-sided pyramid structures. These have the advantage of improving sensitivity.
[0087] The color filter layer 340 is disposed on the pixel array 330. In other words, the pixel array 330 is disposed between the first metal wiring layer 320 and the color filter layer 340. The color filter layer 340 includes at least one color filter, and the specific type of this color filter is not limited in the embodiments of the present application. For example, the color filter is a red color filter, a blue color filter, a green color filter, a yellow color filter, a cyan color filter, a magenta color filter, a white color filter, or an infrared color filter. Adjacent color filters are isolated by an insulator structure 313. The insulator structure 313 includes the insulator material and a metal structure 312. The metal structure 312 is a metal grid.
[0088] The microlens layer 350 is disposed on the color filter layer 340. In other words, the color filter layer 340 is disposed between the pixel array 330 and the microlens layer 350. The microlens layer 350 includes at least one microlens, and the specific type of this microlens is not limited in the embodiments of the present application. Each microslens in the microlens layer 350 is corresponding to a color filter in the color filter layer 340, and each color filter in the color filter layer 340 is corresponding to a PD in the pixel array 330. In other words, the orthographic projection area of the microlens on the surface of the substrate 310 includes the orthographic projection area of the corresponding color filter on the surface of the substrate 310, and the orthographic projection area of the color filter on the surface of the substrate 310 includes the orthographic projection area of the corresponding PD on the surface of the substrate 310.
[0089] FIG. 4 is an example block diagram of a frontside illuminated solid-state imaging device. The frontside illuminated solid-state imaging device in FIG. 4 includes: a substrate 410, a pixel array 420, a second metal wiring layer 430, a color filter layer 440 and a microlens layer 450.
[0090] The substrate 410 is disposed on the bottom layer. The substrate 410 includes a semiconductor material such as silicon or germanium. In some embodiments, the substrate 410 includes at least one or more of other photosensitive materials, such as silicon germanium, silicon carbide, gallium arsenide, gallium phosphide, indium gallium arsenide, indium phosphide, indium arsenide, indium antimonide, semiconductor on insulator or combinations thereof.
[0091] The pixel array 420 is disposed on the substrate 410. The pixel array 420 includes a fourth medium structure and PDs. Adjacent PDs in pixel array 420 are isolated by the fourth medium structure. The types of ions doped in the PD and the fourth medium structure are different. Or, the concentration of ions doped in the fourth medium structure and the PD are different. Or, the fourth medium structure is non-doping. The pixel array 420 is similar to the pixel array 110 in FIG. 1, and the pixel in the pixel array 420 is similar to the pixel in FIG. 2, which will not be repeated here.
[0092] The second metal wiring layer 430 is disposed on the pixel array 420. In other words, the pixel array 420 is disposed between the substrate 410 and the second metal wiring layer 430. The second metal wiring layer 430 includes the first medium, at least one TX and at least one metal structure 411. The first medium, for example, is an oxide, and the specific type of the first medium is not limited in the embodiments of the present application. The metal structure 411 is metal wire or metal block, and the metal structure 411 is connected with the upper surface of the TX. The upper surface of the TX is a surface of the TX away from the substrate 410. The second metal wiring layer 430 is isolated from the PD by the second medium structure and the third medium structure. The types of ions doped in the PD and the second medium structure are different. The types of ions doped in the PD and the third medium structure are different. The types of ions doped in the second medium structure and the third medium structure are different or the same. For example, the PD is made of n-type doping, the second medium structure includes p+ type doping, and the third medium structure is made of p-type doping. The second medium structure is disposed on one side of a first direction of the third medium structure, the first direction is parallel to an upper surface of the substrate 410. The upper surface of the substrate 410 is a surface of substrate 410 near the PD. The FD is disposed in the third medium structure, and the FD includes n+ type doping. The third medium structure includes the third medium, and the fourth medium structure includes the fourth medium. The third medium and the fourth medium are different or the same, which is not limited in the embodiments of the present application. The second metal wiring layer 430 may include, for example, the readout circuit 130 and / or the signal processing circuit 140 as shown in FIG. 1.
[0093] In some embodiments, the TX is a VTG, as described in FIG. 3.
[0094] The color filter layer 440 is disposed on the second metal wiring layer 430. In other words, the second metal wiring layer 430 is disposed between the pixel array 420 and the color filter layer 440. The color filter layer 440 includes color filters. Adjacent color filters are isolated by an insulator structure 413. The insulator structure 413 includes the insulator material and a metal structure 412. The metal structure 412 is a metal grid. The color filter layer 440 is similar to the color filter layer 340 in FIG. 3.
[0095] The microlens layer 450 is disposed on the color filter layer 440. In other words, the color filter layer 440 is disposed between the second metal wiring layer 430 and the microlens layer 450. The microlens layer 450 includes at least one microlens. The microlens layer 450 is similar to the microlens layer 350 in FIG. 3.
[0096] FIG. 5 is an example block diagram of a solid-state imaging device according to an embodiment of this application. There are a frontside illuminated solid-state imaging device 510 and a backside illuminated solid-state imaging device 520 in FIG. 5. The frontside illuminated solid-state imaging device 510 includes: a substrate 511, a first PD 512, a TX 513, a FD 514, a first conductive structure 515 and a second conductive structure 516. The backside illuminated solid-state imaging device 520 includes: a substrate 521, a first metal wiring layer 522, a TX 523, a FD 524, a first conductive structure 525, tahe second conductive structure 526 and a first PD 527. In FIG. 5, a first direction is parallel to an upper surface of the substrate, and a third direction is perpendicular to the upper surface of the substrate. In other words, the first direction is perpendicular to the third direction.
[0097] In the frontside illuminated solid-state imaging device 510, the first PD 512 is disposed on the substrate 511. The TX 513, the FD 514, the first conductive structure 515, and the second conductive structure 516 are disposed on the first PD 512. The FD 514 is disposed on one side of a first direction of the TX 513. The first conductive structure 515 is disposed on a side of the TX 513 away from the FD 514, and the first conductive structure 515 is connected to the first PD 512 and the TX 513. The second conductive structure 516 is disposed between the TX 513 and the FD 514, and the second conductive structure 516 is connected to the TX 513 and the FD 514. The types of ions doped in the first PD 512, the first conductive structure 515, and the second conductive structure 516 are the same.
[0098] In the backside illuminated solid-state imaging device 520, the TX 523, the FD 524, the first conductive structure 525, and the second conductive structure 526 are disposed on the substrate 521. The first PD 527 is disposed on the TX 523, the FD 524, the first conductive structure 525, and the second conductive structure 526. In other words, the first PD 527 is disposed on an upper portion of the substrate 521, and the TX 523, the FD 524, the first conductive structure 525, and the second conductive structure 526 are disposed between the substrate 521 and the first PD 527. The FD 524 is disposed on one side of a first direction of the TX 523. The first conductive structure 525 is disposed on a side of the TX 523 away from the FD 524, and the first conductive structure 525 is connected to the first PD 527 and the TX 523. The second conductive structure 526 is disposed between the TX 523 and the FD 524, and the second conductive structure 526 is connected to the TX 523 and the FD 524. The types of ions doped in the first PD 527, the first conductive structure 525, and the second conductive structure 526 are the same.
[0099] In some embodiments, an isolation structure 517 is disposed on one side of a first direction of the first PD 512 in the frontside illuminated solid-state imaging device 510. The isolation structure 517 is used to isolate adjacent PDs. For example, the isolation structure 517 is the fourth medium structure in FIG. 4. An isolation structure 528 is disposed on one side of a first direction of the first PD 527 in the backside illuminated solid-state imaging device 520. The isolation structure 528 is used to isolate adjacent PDs. For example, the isolation structure 528 includes the fourth medium structure, the fifth medium, and the DTI in FIG. 3.
[0100] In some embodiments, the first conductive structure is connected to the second conductive structure. When the first conductive structure and the second conductive are connected, they can be considered as one conductive structure. For example, the frontside illuminated solid-state imaging device 510 includes a conductive structure, and this conductive structure includes a first part (e.g. first conductive structure 515) and a second part (e.g. second conductive structure 516) . The backside illuminated solid-state imaging device 520 includes a conductive structure, and this conductive structure includes a first part (e.g. first conductive structure 525) and a second part (e.g. second conductive structure 526) .
[0101] In some embodiments, the first PD (e.g. first PD 512 or first PD 527) is made of n-type doping, and the first conductive structure (e.g. first conductive structure 515 or first conductive structure 525) and the second conductive structure (e.g. second conductive structure 516 or second conductive structure 526) are made of n-type doping. Alternatively, the first PD is made of p-type doping, and the first conductive structure and the second conductive structure are made of p-type doping.
[0102] For example, the first conductive structure and the second conductive structure are made of the second material, and the types of ions doped in the first PD and the second material are the same. Alternatively, the first conductive structure is a second PD, and the second conductive structure is made of the second material. The types of ions doped in the first PD and the second PD are the same.
[0103] In some embodiments, a blooming path is controlled by a bias of the TX, the blooming path is a charge transfer path starting from the first PD and sequentially passing through the first conductive structure, the TX, and the second conductive structure to the FD. The bias of the TX is a voltage greater than or equal to -2 V, and the bias of the TX is a voltage less than or equal to +1 V during an exposure.
[0104] FIG. 6 is an example block diagram of a solid-state imaging device according to an embodiment of this application. (a) of FIG. 6 is a part of the pixel array. In (a) of FIG. 6, four pixels are combined into a group in a 2x2 architecture, and (a) of FIG. 6 includes groups of pixels. The devices shown in (a) of FIG. 6 are disposed on an upper portion of the substrate. (b) of FIG. 6 is an enlarged schematic diagram of a group of pixels. In other words, (a) of FIG. 6 includes multiple (b) of FIG. 6. (b) of FIG. 6 includes 4 first PDs, 4 TX, 1 FD, first conductive structures, second conductive structures, 1 RST, 1 DCG, 1 AMP, and 1 SEL. Among them, each of the 4 first PDs corresponds to a TX, and the 4 first PDs share 1 FD, 1 RST, 1 DCG, 1 AMP, and 1 SEL. In the (b) of FIG. 6, the first direction is from the TX in the bottom left to the FD, and the second direction is from the TX in the bottom right to the FD. The first direction and the second directions are parallel to the upper surface of the substrate, and the first direction and the second directions are perpendicular.
[0105] When the solid-state imaging device in FIG. 6 is a frontside illuminated solid-state imaging device, each first PD is disposed on an upper portion of the substrate, and each TX is disposed on the corresponding first PD. The FD is disposed on the first PD, and the FD is disposed on one side of a first direction of the TX. Each first PD corresponds to a first conductive structure and a second conductive structure. The first conductive structure is disposed on a side of the TX away from the FD, and the first conductive structure is connected to the first PD and the TX. The second conductive structure is disposed between the TX and the FD, and the second conductive structure is connected to the TX and the FD.
[0106] When the solid-state imaging device in FIG. 6 is a backside illuminated solid-state imaging device, each first PD is disposed on an upper portion of the substrate, and each TX is disposed between the substrate and the corresponding first PD. The FD is disposed between the substrate and the first PD, and the FD is disposed on one side of a first direction of the TX. Each first PD corresponds to a first conductive structure and a second conductive structure. The first conductive structure is disposed on a side of the TX away from the FD, and the first conductive structure is connected to the first PD and the TX. The second conductive structure is disposed between the TX and the FD, and the second conductive structure is connected to the TX and the FD.
[0107] As shown in FIG. 6, when four pixels belong to a group, the 4 first conductive structures corresponding to the 4 pixels are connected to form a conductive structure. The section of this conductive structure in FIG. 6, for example, is a cross, a square, an octagon or a polygon.
[0108] In (b) of FIG. 6, the RST and DCG are disposed on one side of a group of pixels. The RST and DCG are isolated from the group of pixels through device isolation and electrically connected to the group of pixels. The RST and DCG are also connected to the power supply 1. The AMP and SEL are disposed on one side of a group of pixels and are electrically connected to this group of pixels. The AMP and SEL are connected to the power supply 2 and output. The orthographic projection areas of the FD, the first conductive structure, the second conductive structure, the TX, and the first PD on the upper surface of the substrate partially or completely overlap with the orthographic projection area of the active area on the upper surface of the substrate.
[0109] In some embodiments, each TX in FIG. 6 includes TX part 1 and TX part 2. The angle is formed between TX part 1 and TX part 2, and this angle is greater than 0 degrees. The TX part 1 is parallel to the upper surface of the substrate, and the TX part 2 is perpendicular to the upper surface of the substrate. The TX part 2 is disposed between the TX part 1 and the first PD. The first conductive structure in FIG. 6 is connected to the first FD and TX part 2, and the second conductive structure is connected to the TX part 2 and FD.
[0110] When the solid-state imaging device in FIG. 6 is a backside illuminated solid-state imaging device, the schematic diagram of the section obtained along the tangent AA' in FIG. 6 and the direction perpendicular to the substrate is shown in FIG. 7. When the solid-state imaging device in FIG. 6 is a frontside illuminated solid-state imaging device, the schematic diagram of the section obtained along the tangent AA' in FIG. 6 and the direction perpendicular to the substrate is shown in FIG. 8.
[0111] FIG. 7 is an example block diagram of a backside illuminated solid-state imaging device according to an embodiment of this application. The backside illuminated solid-state imaging device 700 in FIG. 7 includes: a substrate 701, a first metal wiring layer 702, a first medium layer 703, a TX 704, a FD 705, a first conductive structure 706, a second conductive structure 707, a first material layer 708, a shallow trench isolation (STI) 709, a first well 710, a third material layer 711, a first PD 712, a fourth medium structure 713, a fifth medium 714, a DTI 715, a metal structure 716, an insulator structure 717, a color filter 718 and a microlens 719.
[0112] The substrate 701 is disposed on the bottom layer, and the first metal wiring layer 702 is disposed on the upper portion of the substrate 701. The substrate 701 is similar to the substrate 521 in FIG. 5, and the first metal wiring layer 702 is similar to the first metal wiring layer 522 in FIG. 5. The first medium layer 703 is disposed on the first metal wiring layer 702. In other words, the first metal wiring layer 702 is disposed between the substrate 701 and the first medium layer 703. The first medium layer 703 includes the first medium and a part of the TX 704. The first medium layer 703 is similar to the first medium layer in FIG. 3. The TX 704 includes a protruded portion and at least one embedded portion. The protruded portion of TX 704 is disposed in the first medium layer 703. Each embedded portion of the TX 704 is disposed between the protruded portion of the TX 704 and the first PD 712. For example, an angle is formed between each embedded portion and the protruded portion, and this angle is greater than 0 degrees. The TX 704 is similar to the TX 523 in FIG. 5.
[0113] The FD 705, the second conductive structure 707, the first material layer 708, and the STI 709 are disposed on the first medium layer 703. The FD 705 is disposed on one side of a first direction of the TX 704, and the FD 705 is similar to the FD 524 in FIG. 5.
[0114] The second conductive structure 707 is disposed between the FD 705 and the embedded portion of the TX 704, and the second conductive structure 707 is connected to the FD 705 and the embedded portion of TX 704. The second conductive structure 707 is similar to the second conductive structure 526 in FIG. 5.
[0115] In some embodiments, the surface of the second conductive structure 707 is connected to the surface of the TX 704. Alternatively, at least one embedded portion of the TX 704 is embedded in the second conductive structure 707. In some embodiments, the surface of the second conductive structure 707 is connected to the surface of the FD 705. Alternatively, the FD 705 is embedded in the second conductive structure 707.
[0116] The first material layer 708 is disposed on a side of the second conductive structure 707 away from the FD 705. The first material layer 708 is connected to the TX 704 and the STI 709, or, the first material layer 708 is connected to the second conductive structure 707 and the STI 709. The first material layer 708 is also connected to the first medium layer 703 and the first conductive structure 706. In other words, the first material layer 708 is disposed between the first medium layer 703 and the first conductive structure 706. The first material layer 708 includes the first material, and types of ions doped in the first PD 712 and the first material are different. For example, the first PD 712 is made of n-type doping, and the first material is made of p-type doping. Or, the first PD 712 is made of p-type doping, and the first material is made of n-type doping. Or, the first material is made of non-doping.
[0117] The STI 709 is disposed on a side of the first material layer 708 away from the TX 704, and the STI 709 is connected to the first material layer 708. The STI 709 is also disposed between the first medium layer 703 and the first well 710. The STI 709 includes the sixth medium. The sixth medium, for example, is an oxide, and the specific type of the sixth medium is not limited in the embodiments of the present application.
[0118] The fourth medium structure 713 is disposed on a side of the FD 705 away from the first medium layer 703. Adjacent first PDs 712 in the solid-state imaging device are isolated by the fourth medium structure 713. The fourth medium structure 713 is similar to the fourth medium structure in FIG. 3.
[0119] The first PD 712 is disposed on a side of the TX 704 away from the substrate 701. In other words, the FD 705, the first conductive structure 706, the second conductive structure 707, the first material layer 708, the STI 709, the first well 710 and the third material layer 711 are disposed between the first medium layer 703 and the first PD 712. The first PD 712 is similar to the first PD 527 in FIG. 5. The second conductive structure 707 is connected to the first PD 712 by the fourth medium structure 713 and / or the third material layer 711.
[0120] The third material layer 711 is disposed between the second conductive structure 707 and the first PD 712, and the third material layer 711 is disposed between the first conductive structure 706 and fourth medium structure 713. The third material layer 711 includes the third material. The types of ions doped in the first PD and the third material are different. Alternatively, the third material is non-doping.
[0121] The first conductive structure 706 is disposed on a side of the embedded portion of the TX 704 away from the FD 705, and the first conductive structure 706 is connected to the first PD 712 and the embedded portion of the TX 704. The first conductive structure 706 is similar to the first conductive structure 525 in FIG. 5.
[0122] In some embodiments, the surface of the first conductive structure 706 is connected to the surface of the first PD 712. In some embodiments, the surface of the first conductive structure 706 is connected to the surface of the TX 704. Alternatively, at least one embedded portion of the TX 704 is embedded in the first conductive structure 706.
[0123] The first well 710 is disposed on a side of the STI 709 away from the first medium layer 703, and the first well 710 is disposed on a side of the first conductive structure 706 away from the TX 704. The first well 710 is connected to the STI 709 and the fourth medium structure 713, and / or, the first well 710 is connected to the STI 709 and the first PD 712. The first well 710 is also connected to the first conductive structure 706. Adjacent first PDs 712 is isolated by the fourth medium structure 713, the fifth medium 714 and the DTI 715. The fifth medium 714 is similar to the fifth medium in FIG. 3, and the DTI 715 is similar to the DTI in FIG. 3. The metal structure 716, the insulator structure 717, the color filter 718 and the microlens 719 are disposed on a side of the DTI 715 away from the substrate 701. The metal structure 716 is similar to the metal structure 312 in FIG. 3, the insulator structure 717 is similar to the insulator structure 313 in FIG. 3, the color filter 718 is similar to the color filter in FIG. 3, and the microlens 719 is similar to the microlens in FIG. 3.
[0124] In some embodiments, the depth of DTI is shorter than the photo conversion material thickness (as shown in FIG. 7) . Alternatively, the depth of DTI is equal to or greater than the photo conversion material thickness.
[0125] FIG. 8 is an example block diagram of a frontside illuminated solid-state imaging device according to an embodiment of this application. The frontside illuminated solid-state imaging device in FIG. 8 includes: a substrate 801, a first PD 802, a fourth medium structure 803, a TX 804, a FD 805, a first conductive structure 806, a second conductive structure 807, a first material layer 808, a third material layer 809, a first medium layer 810, a metal structure 811, an insulator structure 812, a color filter 813 and a microlens 814.
[0126] The substrate 801 is disposed on the bottom layer, and the first PD 802 and the fourth medium structure 803 are disposed on the upper portion of the substrate 801. The first PD 802 is similar to the first PD 512 in FIG. 5. Adjacent first PDs 802 in the solid-state imaging device are isolated by the fourth medium structure 803. The fourth medium structure 803 is similar to the fourth medium structure in FIG. 4.
[0127] The TX 804, the FD 805, the first conductive structure 806, the second conductive structure 807 and the third material layer 809 are disposed on the first PD 802. The TX 804 includes a protruded portion and at least one embedded portion. The protruded portion of TX 804 is disposed in the first medium layer 810. Each embedded portion of the TX 804 is disposed between the protruded portion of the TX 804 and the first PD 802. For example, an angle is formed between each embedded portion and the protruded portion, and this angle is greater than 0 degrees. The TX 804 is similar to the TX 513 in FIG. 5.
[0128] The FD 805 is disposed on one side of a first direction of the TX 804, and the FD 805 is connected to the substrate 801 by the fourth medium structure 803. The FD 805 is similar to the FD 514 in FIG. 5.
[0129] The first conductive structure 806 is disposed on a side of the embedded portion of the TX 804 away from the FD 805, and the first conductive structure 806 is connected to the first PD 802 and the embedded portion of the TX 804. The first conductive structure 806 is also disposed between the fourth medium structure 803 and the embedded portion of the TX 804, and the first conductive structure 806 is connected to the fourth medium structure 803. The first conductive structure 806 is similar to the first conductive structure 515 in FIG. 5.
[0130] In some embodiments, the surface of the first conductive structure 806 is connected to the surface of the first PD 802. In some embodiments, the surface of the first conductive structure 806 is connected to the surface of the TX 804. Alternatively, at least one embedded portion of the TX 804 is embedded in the first conductive structure 806.
[0131] The second conductive structure 807 is disposed between the FD 805 and the embedded portion of the TX 804, and the second conductive structure 807 is connected to the FD 805 and the embedded portion of TX 804. The second conductive structure 807 is connected to the first PD 802 by the fourth medium structure 803 and / or the third material layer 809. The second conductive structure 807 is similar to the second conductive structure 516 in FIG. 5.
[0132] In some embodiments, the surface of the second conductive structure 807 is connected to the surface of the TX 804. Alternatively, at least one embedded portion of the TX 804 is embedded in the second conductive structure 807. In some embodiments, the surface of the second conductive structure 807 is connected to the surface of the FD 805. Alternatively, the FD 805 is embedded in the second conductive structure 807.
[0133] The third material layer 809 is disposed between the second conductive structure 807 and the first PD 802, and the third material layer 809 is disposed between the first conductive structure 806 and fourth medium structure 803. The third material layer 809 includes the third material. The types of ions doped in the first PD and the third material are different. Alternatively, the third material is non-doping.
[0134] The first material layer 808 is disposed on a side of the second conductive structure 807 away from the FD 805. The first material layer 808 is connected to the TX 804 or the second conductive structure 807. The first material layer 808 is also connected to the first medium layer 810 and the first conductive structure 806, and / or, the first material layer 808 is also connected to the first medium layer 810 and the fourth medium structure 803. In other words, the first material layer 808 is disposed between the first medium layer 810 and the first conductive structure 806. The first material layer 808 includes the first material. The types of ions doped in the first PD 802 and the first material are different. Alternatively, the first material is non-doping.
[0135] The first medium layer 810 is disposed on the FD 805, the second conductive structure 807 and the first material layer 808. The first medium layer 810 includes the first medium and the protruded portion of the TX 804. The first medium layer 810 is similar to the first medium layer in FIG. 4.
[0136] The metal structure 811, the insulator structure 812, the color filter 813 and the microlens 814 are disposed on a side of the first medium layer 810 away from the substrate 801. The metal structure 811 is similar to the metal structure 412 in FIG. 4, the insulator structure 812 is similar to the insulator structure 413 in FIG. 4, the color filter 813 is similar to the color filter in FIG. 4, and the microlens 814 is similar to the microlens in FIG. 4.
[0137] The embodiments of the present application do not limit the specific shape of the first conductive structure and / or the second conductive structure. For example, the first conductive structure and / or the second conductive structure are cylinders, prisms, cubes, rectangles, cones, prisms, or irregularly shaped cubes, etc. Alternatively, the shape of the first conductive structure and / or the second conductive structure on the first section is circular, elliptical, triangular, quadrilateral, or polygonal, etc. And the specific direction of the first section is not limited by the embodiments of the present application.
[0138] Optionally, the first conductive structure includes a first part far from the TX and a second part near the TX, the first part and the second part of the first conductive structure have the same width in a second direction, or, the first part and the second part of the first conductive structure have different widths in a second direction. The second direction is parallel to the upper surface of the substrate, and the second direction is perpendicular to the first direction. Similarly, the second conductive structure includes a first part near the TX and a second part near the FD, the first part and the second part of the second conductive structure have the same width in a second direction, or, the first part and the second part of the second conductive structure have different widths in a second direction.
[0139] FIG. 9 illustrates the second conductive structure as an example. It should be understood that the shape of the first conductive structure is similar to that of the second conductive structure, and will not be repeated here. It should also be understood that the shape of the first conductive structure and the second conductive structure can be the same or different, and the embodiments of the present application is not limited to this.
[0140] FIG. 9 illustrates a section of the solid-state imaging device, and this section is formed along the first direction and the second direction. The solid-state imaging device in FIG. 9 is a backside or frontside illuminated solid-state imaging device. The solid-state imaging device in FIG. 9 includes: a first PD 901, a FD 902, a TX 903, a second conductive structure 906 and a first conductive structure 907. The TX 903 includes a protruded portion 904 and two embedded portions 905. The second conductive structure 906 includes a first part near the TX 903 and a second part near the FD 902. The orthographic projection area of the second conductive structure 906 on the upper surface of the substrate partially overlaps with the orthographic projection area of the TX 903 on the upper surface of the substrate, and the orthographic projection area of the second conductive structure 906 on the upper surface of the substrate partially overlaps with the orthographic projection area of the FD 902 on the upper surface of the substrate. As shown in (a) and (d) of FIG. 9, the first part and the second part of the second conductive structure 906 have the same width in the second direction. As shown in (b) of FIG. 9, a width of the first part of the second conductive structure 906 in the second direction is greater than a width of the second part of the second conductive structure 906 in the second direction. As shown in (c) of FIG. 9, a width of the first part of the second conductive structure 906 in the second direction is shorter than a width of the second part of the second conductive structure 906 in the second direction.
[0141] As shown in (a) , (b) and (c) of FIG. 9, the orthographic projection of each embedded portion 905 of TX 903 on the upper surface of the substrate partially overlaps with the orthographic projection of the second conductive structure 906 on the upper surface of the substrate. As shown in (d) of FIG. 9, the orthographic projection area of the second conductive structure 906 on the upper surface of the substrate covers the orthographic projection area of each embedded portion 905 of TX 903 on the upper surface of the substrate. As shown in (a) , (b) , (c) and (d) of FIG. 9, the shape of the second conductive structure 906 in the section shown in FIG. 9 is quadrilateral. As shown in (e) of FIG. 9, the shape of the second conductive structure 906 in the section shown in FIG. 9 is irregular polygons. FIG. 9 shows high pixel charge transfer capability because of solid transfer paths from PD to FD.
[0142] Optionally, the first conductive structure and the second conductive structure have different widths in the second direction. Alternatively, the first conductive structure and the second conductive structure have the same width in the second direction. In some embodiments, the shape and size of the first conductive structure and the second conductive structure are the same, so each corresponding part of the first conductive structure and the second conductive structure have the same width in the second direction. Alternatively, the shape and / or size of the first conductive structure and the second conductive structure are different. A part of the first conductive structure and a part of the second conductive structure have different widths in the second direction, or a part of the first conductive structure and a part of the second conductive structure have the same width in the second direction.
[0143] FIG. 10 illustrates a section of the solid-state imaging device, and this section is formed along the first direction and the second direction. The solid-state imaging device in FIG. 10 is a backside or frontside illuminated solid-state imaging device. The solid-state imaging device in FIG. 10 includes: a first PD 901, a FD 902, a TX 903, a second conductive structure 906 and a first conductive structure 907. The TX 903 includes a protruded portion 904 and two embedded portions 905. The first conductive structure 907 includes a first part far from the TX 903 and a second part near the TX 903. The orthographic projection area of the first conductive structure 907 on the upper surface of the substrate partially overlaps with the orthographic projection area of the TX 903 on the upper surface of the substrate, and the orthographic projection area of the first conductive structure 907 on the upper surface of the substrate partially overlaps with the orthographic projection area of the first PD 901 on the upper surface of the substrate.
[0144] As shown in (a) of FIG. 10, the first part and the second part of the first conductive structure 907 have the same width in the second direction, the first part and the second part of the second conductive structure 906 have the same width in the second direction, and the first conductive structure 907 and the second conductive structure 906 have the same width in the second direction. As shown in (b) of FIG. 10, the first part and the second part of the first conductive structure 907 have the same width in the second direction, the first part and the second part of the second conductive structure 906 have different widths in the second direction, the first conductive structure 907 and the first part of the second conductive structure 906 have the same width in the second direction, and the width of the first conductive structure 907 in the second direction is shorter than the width of the second part of the second conductive structure 906 in the second direction. As shown in (c) of FIG. 10, the first conductive structure 907 is an irregular polygon in the section shown in FIG. 10, approximately L-shaped, the second conductive structure 906 is a rectangle in the section shown in FIG. 10, the second conductive structure 906 and one part of the first conductive structure 907 have the same width in the second direction, and the second conductive structure 906 and another part of the first conductive structure 907 have different widths in the second direction. As shown in (d) of FIG. 10, the first part and the second part of the first conductive structure 907 have the same width in the second direction, the first part and the second part of the second conductive structure 906 have the same width in the second direction, and the width of the first conductive structure 907 in the second direction is shorter than the width of the second conductive structure 906 in the second direction. As shown in (e) of FIG. 10, the first part and the second part of the first conductive structure 907 have the same width in the second direction, the first part and the second part of the second conductive structure 906 have the same width in the second direction, and the width of the first conductive structure 907 in the second direction is greater than the width of the second conductive structure 906 in the second direction.
[0145] As shown in (a) , (b) and (c) of FIG. 10, the orthographic projection of each embedded portion 905 of TX 903 on the upper surface of the substrate partially overlaps with the orthographic projection of the first conductive structure 907 on the upper surface of the substrate, and the orthographic projection of each embedded portion 905 of TX 903 on the upper surface of the substrate partially overlaps with the orthographic projection of the second conductive structure 906 on the upper surface of the substrate. As shown in (d) of FIG. 10, the orthographic projection of each embedded part 905 of TX 903 on the upper surface of the substrate does not overlap with the orthographic projection of the first conductive structure 907 on the upper surface of the substrate, and the orthographic projection area of the second conductive structure 906 on the upper surface of the substrate covers the orthographic projection area of each embedded portion 905 of TX 903 on the upper surface of the substrate. As shown in (e) of FIG. 10, the orthographic projection area of the first conductive structure 907 on the upper surface of the substrate covers the orthographic projection area of each embedded portion 905 of TX 903 on the upper surface of the substrate, and the orthographic projection of each embedded part 905 of TX 903 on the upper surface of the substrate does not overlap with the orthographic projection of the second conductive structure 906 on the upper surface of the substrate. FIG. 10 shows high pixel charge transfer capability because of solid transfer paths from PD to FD.
[0146] Optionally, the first part and the second part of the first conductive structure have the same width in the third direction (as shown in FIG. 7, FIG. 8, (a) , (b) , (c) of FIG. 12, (a) , (b) , (c) , (d) , (e) of FIG. 13) , or, the first part and the second part of the first conductive structure have different widths in a third direction. For example, the width of the first part of the first conductive structure in the third direction is shorter than the width of the second part of the first conductive structure in the third direction (as shown in (f) of FIG. 13) . Alternatively, the width of the first part of the first conductive structure in the third direction is greater than the width of the second part of the first conductive structure in the third direction. Similarly, the width of the first part of the second conductive structure in the third direction is shorter than or equal to the width of the second part of the second conductive structure in the third direction. Alternatively, the width of the first part of the second conductive structure in the third direction is greater than the width of the second part of the second conductive structure in the third direction.
[0147] Optionally, the first conductive structure and the second conductive structure have different widths in the third direction. Alternatively, the first conductive structure and the second conductive structure have the same width in the third direction. In some embodiments, the shape and size of the first conductive structure and the second conductive structure are the same, so each corresponding part of the first conductive structure and the second conductive structure have the same width in the third direction. Alternatively, the shape and / or size of the first conductive structure and the second conductive structure are different. A part of the first conductive structure and a part of the second conductive structure have different widths in the third direction, or a part of the first conductive structure and a part of the second conductive structure have the same width in the third direction.
[0148] Optionally, the TX includes a protruded portion and at least one embedded portion. Each embedded portion of the TX is disposed between the protruded portion and the first PD, an angle is formed between each embedded portion and the protruded portion, and this angle is greater than 0 degrees. The embodiments of the present application do not limit the specific shape of the protruded portion and each embedded portion of the TX, such as the protruded portion and / or embedded portion being a cylinder, prism, cube, cuboid, cone, pyramid or irregularly shaped cube, etc. Alternatively, the shape of the protruded portion and / or embedded portion on the first section is circular, elliptical, triangular, quadrilateral, or polygonal, and the specific direction of the first section is not limited by the embodiments of the present application.
[0149] Optionally, when the TX includes embedded portions, at least two embedded portions of the TX have different sizes and / or shapes, or, at least two embedded portions of the TX have the same size and / or shape. Alternatively, the shape and / or size of the orthographic projection area of at least two of the embedded portions on the upper surface of the substrate can be the same or different, as shown in FIG. 11.
[0150] FIG. 11 illustrates a section of the solid-state imaging device, and this section is formed along the first direction and the second direction. The solid-state imaging device in FIG. 11 is a backside or frontside illuminated solid-state imaging device. As shown in (a) of FIG. 11, the TX 903 includes a protruded portion 904 and two embedded portions 905, the shape and size of the orthographic projection area of the two embedded portions 905 on the upper surface of the substrate are the same. As shown in (b) of FIG. 11, the TX 903 includes a protruded portion 904 and an embedded portion 905. As shown in (c) of FIG. 11, the TX 903 includes a protruded portion 904 and three embedded portions 905, the shape and size of the orthographic projection area of the three embedded portions 905 on the upper surface of the substrate are the same. As shown in (d) of FIG. 11, the TX 903 includes a protruded portion 904 and two embedded portions 905, the shape of the orthographic projection area of the two embedded portions 905 on the upper surface of the substrate are the same, and the size of the orthographic projection area of the two embedded portions 905 on the upper surface of the substrate are different. As shown in (a) , (b) , (c) and (d) of FIG. 11, the orthographic projection of the protruded portion 904 and each embedded portion 905 of TX 903 on the upper surface of the substrate partially overlaps with the orthographic projection of the first conductive structure 907 on the upper surface of the substrate, and the orthographic projection of the protruded portion 904 and each embedded portion 905 of TX 903 on the upper surface of the substrate partially overlaps with the orthographic projection of the second conductive structure 906 on the upper surface of the substrate. FIG. 11 shows high layout design flexibility while keeping fundamental pixel performance, such as full well capacity, lag, and blooming.
[0151] Optionally, as shown in FIG. 9 and FIG. 10, the orthographic projection area of the TX on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the first conductive structure on the upper surface of the substrate. And / or, the orthographic projection area of the TX on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the second conductive structure on the upper surface of the substrate. The orthographic projection area of the TX on the upper surface of the substrate includes: the orthographic projection area of the protruded portion of the TX on the upper surface of the substrate and the orthographic projection area of the protruded portion of each embedded portion of the TX on the upper surface of the substrate. In some embodiments, the orthographic projection area of the first conductive structure (and / or the second conductive structure) on the upper surface of the substrate covers the orthographic projection area of the TX on the upper surface of the substrate. Or, the orthographic projection area of the TX on the upper surface of the substrate covers the orthographic projection area of the first conductive structure (and / or the second conductive structure) on the upper surface of the substrate.
[0152] In some embodiments, the first orthographic projection area covers the second orthographic projection means the first orthographic projection completely overlaps with the second orthographic projection. When the edges of two orthographic projection areas are connected, or when the same area is included in both orthographic projection areas, it can be considered that the two orthographic projection areas partially overlap.
[0153] Optionally, the orthographic projection area of the FD on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the second conductive structure on the upper surface of the substrate, as shown in FIG. 9 and FIG. 10. Alternatively, the orthographic projection area of the second conductive structure on the upper surface of the substrate covers the orthographic projection area of the FD on the upper surface of the substrate.
[0154] Optionally, a first distance and a second distance are different or the same. The first distance is a distance between a first surface of the first conductive structure and the upper surface of the substrate, and the first surface of the first conductive structure is a surface of the first conductive structure near the first PD. The second distance is a distance between a first surface of the second conductive structure and the upper surface of the substrate, and the first surface of the second conductive structure is a surface of the second conductive structure near the first PD.
[0155] In some embodiments, the distances between each part of the first surface of the first conductive structure and the upper surface of the substrate are the same. Alternatively, the distances between at least two parts of the first surface of the first conductive structure and the upper surface of the substrate are different. Similarly, the distances between each part of the first surface of the second conductive structure and the upper surface of the substrate are the same. Alternatively, the distances between at least two parts of the first surface of the second conductive structure and the upper surface of the substrate are different.
[0156] In some embodiments, the distance between a part of the first surface of the first conductive structure and the upper surface of the substrate is different from (or the same as) the distance between a part or all of the first surface of the second conductive structure and the upper surface of the substrate.
[0157] For example, the distances between each part of the first surface of the first conductive structure and the upper surface of the substrate are the same, and the distances between each part of the first surface of the second conductive structure and the upper surface of the substrate are the same. In the backside illuminated solid-state imaging device, the first distance is greater than the second distance (as shown in FIG. 7) , or the first distance is equal to the second distance (as shown in (a) of FIG. 12) , or the first distance is shorter than the second distance (as shown in (b) of FIG. 12) . Similarly, in the frontside illuminated solid-state imaging device, the first distance is shorter than the second distance (as shown in FIG. 8) , or the first distance is greater than or equal to the second distance.
[0158] FIG. 12 is an example block diagram of a solid-state imaging device according to an embodiment of this application. The solid-state imaging device in FIG. 12 is a backside illuminated solid-state imaging device. It should be understood that the frontside illuminated solid-state imaging device can have a structure similar to the first conductive structure and the second conductive structure shown in FIG. 12. For simplicity, it will not be repeated here.
[0159] As shown in FIG. 12, the first surface of the first conductive structure 706 is a surface of the first conductive structure 706 near the first PD 712, and the first surface of the second conductive structure 707 is a surface of the second conductive structure 707 near the first PD 712. As shown in (a) of FIG. 12, the distance between the first surface of the first conductive structure 706 and the upper surface of the substrate 701 is the same as the distance between the first surface of the second conductive structure 707 and the upper surface of the substrate 701, and the orthographic projection area of the FD 705 on the upper surface of the substrate 701 partially overlaps with the orthographic projection area of the second conductive structure 707 on the upper surface of the substrate 701. As shown in (b) of FIG. 12, the distance between the first surface of the first conductive structure 706 and the upper surface of the substrate 701 is shorter than the distance between the first surface of the second conductive structure 707 and the upper surface of the substrate 701, and the orthographic projection area of the FD 705 on the upper surface of the substrate 701 partially overlaps with the orthographic projection area of the second conductive structure 707 on the upper surface of the substrate 701. As shown in (c) of FIG. 12, the distance between the first surface of the first conductive structure 706 and the upper surface of the substrate 701 is the same as the distance between the first surface of the second conductive structure 707 and the upper surface of the substrate 701, and the orthographic projection area of the second conductive structure 707 on the upper surface of the substrate 701 covers the orthographic projection area of the FD 705 on the upper surface of the substrate 701. In other words, the FD 705 is fully embedded in the second conductive structure 707 in (c) of FIG. 12. FIG. 12 shows high pixel charge transfer capability because of solid transfer paths from PD to FD.
[0160] Optionally, a third distance and a fourth distance are different or the same. The third distance is a distance between a second surface of the first conductive structure and the upper surface of the substrate, and the second surface of the first conductive structure is a surface of the first conductive structure away from the first PD. The fourth distance is a distance between a second surface of the second conductive structure and the upper surface of the substrate, and the second surface of the second conductive structure is a surface of the second conductive structure away from the first PD.
[0161] In some embodiments, the distances between each part of the second surface of the first conductive structure and the upper surface of the substrate are the same. Alternatively, the distances between at least two parts of the second surface of the first conductive structure and the upper surface of the substrate are different. Similarly, the distances between each part of the second surface of the second conductive structure and the upper surface of the substrate are the same. Alternatively, the distances between at least two parts of the second surface of the second conductive structure and the upper surface of the substrate are different.
[0162] In some embodiments, the distance between a part of the second surface of the first conductive structure and the upper surface of the substrate is different from (or the same as) the distance between a part or all of the second surface of the second conductive structure and the upper surface of the substrate.
[0163] Optionally, in the solid-state imaging device which includes the STI (as shown in FIG. 7) , the first surface of the STI is a surface of the STI near the first PD. The distance between the first surface of the STI and the upper surface of the substrate is different from (or the same as) the first distance, and / or, the distance between the first surface of the STI and the upper surface of the substrate is different from (or the same as) the second distance. For example, the distance between the first surface of the STI and the upper surface of the substrate is shorter than the first distance, as shown in FIG. 7. Alternatively, the distance between the first surface of the STI and the upper surface of the substrate is greater than or equal to the first distance.
[0164] Optionally, in the solid-state imaging device which includes the STI (as shown in FIG. 7) , the second surface of the STI is a surface of the STI away from the first PD. The distance between the second surface of the STI and the upper surface of the substrate is different from (or the same as) the third distance, and / or, the distance between the second surface of the STI and the upper surface of the substrate is different from (or the same as) the fourth distance. For example, the distance between the second surface of the STI and the upper surface of the substrate is shorter than the third distance, as shown in FIG. 7. Alternatively, the distance between the second surface of the STI and the upper surface of the substrate is greater than or equal to the third distance.
[0165] Optionally, in the backside illuminated solid-state imaging device which includes the DTI (as shown in FIG. 7) , the first surface of the DTI is a surface of the DTI near the substrate. The distance between the first surface of the DTI and the upper surface of the substrate is different from (or the same as) the first distance, and / or, the distance between the first surface of the DTI and the upper surface of the substrate is different from (or the same as) the second distance. For example, the distance between the first surface of the DTI and the upper surface of the substrate is greater than the first distance, as shown in FIG. 7. Alternatively, the distance between the first surface of the DTI and the upper surface of the substrate is shorter than or equal to the first distance.
[0166] Optionally, in frontside illuminated the solid-state imaging device which includes the DTI, the second surface of the DTI is a surface of the DTI away from the substrate. The distance between the second surface of the DTI and the upper surface of the substrate is different from (or the same as) the third distance, and / or, the distance between the second surface of the DTI and the upper surface of the substrate is different from (or the same as) the fourth distance. For example, the distance between the second surface of the DTI and the upper surface of the substrate is shorter than the third distance. Alternatively, the distance between the second surface of the DTI and the upper surface of the substrate is greater than or equal to the third distance.
[0167] Optionally, the solid-state imaging device also includes a first material layer. The first material layer is disposed on a side of the first conductive structure (and / or the second conductive structure) away from the first PD. The types of ions doped in the first PD and the first material layer are different, or, the first material layer is made of non-doping.
[0168] In some embodiments, the first material layer is disposed between the first conductive structure (and / or the second conductive structure) and the protruded portion of the TX.
[0169] In some embodiments, an orthographic projection area of the protruded portion of the TX on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the first material layer on the upper surface of the substrate. Or, the orthographic projection area of the first material layer on the upper surface of the substrate covers the orthographic projection area of the protruded portion of the TX on the upper surface of the substrate. Or, the orthographic projection area of the protruded portion of the TX on the upper surface of the substrate covers the orthographic projection area of the first material layer on the upper surface of the substrate.
[0170] FIG. 13 is an example block diagram of a solid-state imaging device according to an embodiment of this application. The solid-state imaging device in FIG. 13 is a backside illuminated solid-state imaging device. It should be understood that the frontside illuminated solid-state imaging device can have a structure similar to the first conductive structure and the second conductive structure shown in FIG. 13. For simplicity, it will not be repeated here.
[0171] As shown in FIG. 13, the second surface of the first conductive structure 706 is a surface of the first conductive structure 706 away from the first PD 712, and the second surface of the second conductive structure 707 is a surface of the second conductive structure 707 away from the first PD 712.
[0172] As shown in (a) of FIG. 13, the distance between the second surface of the first conductive structure 706 and the upper surface of the substrate 701 is the same as the distance between the second surface of the second conductive structure 707 and the upper surface of the substrate 701. The first material layer 708 is disposed on a side of the first conductive structure 706 and the second conductive structure 707 away from the first PD 712, the first material layer 708 is connected to the first medium layer 703 and the first conductive structure 706, and the first material layer 708 is connected to the first medium layer 703 and the second conductive structure 707. The first material layer 708 includes the first material, and the first material is similar to the first material in the above embodiments of the present application.
[0173] As shown in (b) of FIG. 13, the distance between the second surface of the first conductive structure 706 and the upper surface of the substrate 701 is greater than the distance between the second surface of the second conductive structure 707 and the upper surface of the substrate 701. The fourth material layer 720 is disposed between the first conductive structure 706 and the first material layer 708. The types of ions doped in the first PD 712 and the fourth material layer 720 are different, or the fourth material layer 720 is made of non-doping. The fourth material layer 720 includes the fourth material, and the third material in FIG. 7 and the fourth material are different or the same. The second conductive structure 707 is connected to the first material layer 708.
[0174] As shown in (c) of FIG. 13, the distance between the second surface of the first conductive structure 706 and the upper surface of the substrate 701 is greater than the distance between the second surface of the second conductive structure 707 and the upper surface of the substrate 701. The first material layer 708 is disposed on a side of the first conductive structure 706 and the second conductive structure 707 away from the first PD 712.
[0175] As shown in (d) of FIG. 13, the distance between the second surface of the first conductive structure 706 and the upper surface of the substrate 701 is greater than the distance between the second surface of the second conductive structure 707 and the upper surface of the substrate 701. The fourth material layer 720 is disposed between the first conductive structure 706 and the first medium layer 703. The first material layer 708 is disposed between the second conductive structure 707 and the first medium layer 703.
[0176] As shown in (e) of FIG. 13, the distance between the second surface of the first conductive structure 706 and the upper surface of the substrate 701 is greater than the distance between the second surface of the second conductive structure 707 and the upper surface of the substrate 701. The first material layer 708 and the fourth material layer 720 are disposed on a side of the first conductive structure 706 away from the first PD 712. The first material layer 708 is connected to the first medium layer 703 and the first conductive structure 706, and the fourth material layer 720 is connected to the first material layer 708 and the first conductive structure 706. The first material layer 708 is also disposed on a side of the second conductive structure 707 away from the first PD 712, and the first material layer 708 is connected to the second conductive structure 707 and the first medium layer 703.
[0177] As shown in (a) , (b) , (c) , (d) and (e) of FIG. 13, the distances between each part of the second surface of the first conductive structure 706 and the upper surface of the substrate 701 are the same, and the distances between each part of the second surface of the second conductive structure 707 and the upper surface of the substrate 701 are the same. As shown in (f) of FIG. 13, the distance between the surface away from the TX in the second surface of the first conductive structure 706 and the upper surface of the substrate 701 is greater than the distance between the surface near the TX in the second surface of the first conductive structure 706 and the upper surface of the substrate 701. The distance between the surface near the TX in the second surface of the second conductive structure 707 and the upper surface of the substrate 701 is greater than the distance between the surface near the FD in the second surface of the second conductive structure 707 and the upper surface of the substrate 701. The first material layer 708 is disposed on a side of the first conductive structure 706 and the second conductive structure 707 away from the first PD 712. FIG. 13 shows a low dark current because of strong valence band pinning.
[0178] Optionally, the first surface of the first material layer is a surface of the first material layer near the first conductive structure (and / or the second conductive structure) . The distances between each part of the first surface of the first material layer and the upper surface of the substrate are the same, as shown in (a) , (b) and (d) of FIG. 13. Alternatively, the distances between at least two parts of the first surface of the first material layer and the upper surface of the substrate are different, as shown in (c) , (e) and (f) of FIG. 13.
[0179] Optionally, the second distance and a fifth distance are different or the same. The fifth distance is a distance between a first surface of the FD and the upper surface of the substrate, and the first surface of the FD is a surface of the FD near the first PD.
[0180] For example, as shown in FIG. 7 or FIG. 8, the fifth distance is the same as the second distance. Or, as shown in (a) , (b) and (c) of FIG. 12, the fifth distance is shorter than the second distance. Or, the fifth distance is greater than the second distance.
[0181] In some embodiments, the distances between each part of the first surface of the FD and the upper surface of the substrate are the same. Alternatively, the distances between at least two parts of the first surface of the FD and the upper surface of the substrate are different.
[0182] In some embodiments, the distance between a part of the first surface of the FD and the upper surface of the substrate is different from (or the same as) the distance between a part or all of the first surface of the second conductive structure and the upper surface of the substrate.
[0183] The solid-state imaging device according to the embodiments of this application achieves the pixel size scaling, increases the FWC and dynamic range accordingly, enlarges the image lag margin which can be used for lower VDD operation, increases blooming design margin, improves dark performance (such as lower dark current and / or more white pixels) , improves pixel layout flexibility, decreases pixel noise which leading to higher signal-to-noise ratio, and improves yield because of the robust process and many self-align processes.
[0184] FIG. 14 is an example block diagram of a solid-state imaging device according to an embodiment of this application. There are a solid-state imaging device A, a solid-state imaging device B, a solid-state imaging device C, a solid-state imaging device D and a solid-state imaging device E in FIG. 14.
[0185] The solid-state imaging device A includes: a pixel array 1411, a control circuit 1420 and a logic circuit 1430. The pixel array 1411, the control circuit 1420 and the logic circuit 1430 are disposed on the same substrate, and this substrate is a semiconductor substrate, such as bulk or semiconductor on insulator. This substrate is similar to the substrate in FIG. 5 to FIG. 13.
[0186] The pixel array 1411 includes: at least one PD, at least one TX, at least one FD, at least one first conductive structure, at least one second conductive structure, at least one DCG, at least one RST, at least one AMP and at least one SEL. The pixel array 1411 is a frontside illumination or backside illumination. The PD, TX, FD, first conductive structure and second conductive structure are similar to the corresponding structure in FIG. 5 to FIG. 13.
[0187] In some embodiments, the pixel array 1411 also includes any one or more of the first material layer, the third material layer, or the fourth material layer. The first material layer, the third material layer and the fourth material layer are similar to the corresponding structure in the above embodiments of the present application.
[0188] The control circuit 1420 controls the pixel array 1411, and the control circuit 1420 is similar to the control circuit 120 in FIG. 1. The signal processing circuit 1430 obtains and processes the image data which is generated by the pixel array 1411. The signal processing circuit 1430 includes the readout circuit 130 and / or the signal processing circuit 140.
[0189] The solid-state imaging device B includes: a pixel array 1411, a control circuit 1420 and a logic circuit 1430. The pixel array 1411 and the control circuit 1420 are disposed on a first substrate, and the logic circuit 1430 is disposed on a second substrate. The first substrate and the second substrate are electrically connected to each other to form the solid-state imaging device. The first substrate and / or the second substrate are a semiconductor substrate, such as a bulk or semiconductor on an insulator. The first substrate and / or the second substrate are similar to the substrate in FIG. 5 to FIG. 13.
[0190] The solid-state imaging device C includes: a pixel array 1411, a control circuit 1420 and a logic circuit 1430. The pixel array 1411 is disposed on the first substrate, and the control circuit 1420 and the logic circuit 1430 are disposed on the second substrate. The first substrate and the second substrate are electrically connected to each other to form the solid-state imaging device.
[0191] The solid-state imaging device D includes: a pixel array 1411, a memory circuit 1440, a control circuit 1420 and the logic circuit 1430. The pixel array 1411 is disposed on the first substrate, the memory circuit 1440 is disposed on the second substrate, and the control circuit 1420 and the logic circuit 1430 are disposed on a third substrate. The first substrate, the second substrate and the third substrate are electrically connected to each other to form the solid-state imaging device. The third substrate is a semiconductor substrate, such as a bulk or semiconductor on an insulator. The third substrate is similar to the substrate in FIG. 5 to FIG. 13. The memory circuit 1440 is used to store the image data which is generated by the pixel array 1411.
[0192] The solid-state imaging device E includes: a pixel array 1412, a pixel circuit 1450, a control circuit 1420 and the logic circuit 1430. The pixel array 1412 is disposed on the first substrate, the pixel circuit 1450 is disposed on the second substrate, and the control circuit 1420 and the logic circuit 1430 are disposed on the third substrate. The first substrate, the second substrate and the third substrate are electrically connected to each other to form the solid-state imaging device. The pixel array 1412 includes: at least one PD, at least one TX, at least one FD, at least one first conductive structure and at least one second conductive structure. The pixel circuit 1450 includes: at least one DCG, at least one RST, at least one AMP and at least one SEL.
[0193] In some embodiments, the pixel array 1412 also includes any one or more of the first material layer, the third material layer, or the fourth material layer. The first material layer, the third material layer and the fourth material layer are similar to the corresponding structure in the above embodiments of the present application.
[0194] FIG. 15 is an example block diagram of a solid-state imaging system according to an embodiment of this application. A solid-state imaging system 1500 in FIG. 15 includes: an optical system 1510, a shutter system 1520, a solid-state imaging device 1530, a control circuit 1540, a signal processing circuit 1550, a monitor 1560, and a memory 1570. The optical system 1510 includes at least one lens. The solid-state imaging device 1530 includes a readout circuit and the solid-state imaging device in FIG. 5 to FIG. 13, and the readout circuit is similar to the readout circuit 130 in FIG. 1. The control circuit 1540 is similar to the control circuit 120 in FIG. 1. Under the control of the control circuit 1540, image data of the object is obtained through the optical system 1510 and the shutter system 1520. The signal processing circuit 1550 outputs the image data to the monitor 1560 or stores the image data in the memory 1570. The signal processing circuit 1550 is similar to the signal processing circuit 140 in FIG. 1.
[0195] FIG. 16 is a schematic diagram of a method of making a solid-state imaging device according to an embodiment of this application. The method in FIG. 16 is used to form the solid-state imaging devices as shown in FIG. 5 to FIG. 13. This method includes the following steps.
[0196] Step 1610: forming a substrate.
[0197] The substrate includes a semiconductor material such as silicon or germanium. In some embodiments, the substrate includes at least one or more of other photosensitive materials, such as silicon germanium, silicon carbide, gallium arsenide, gallium phosphide, indium gallium arsenide, indium phosphide, indium arsenide, indium antimonide, semiconductor on insulator or combinations thereof. The substrate is similar to the substrate 511 or the substrate 521 in FIG. 5.
[0198] Step 1620: forming a first photodiode (PD) , a transfer gate (TX) , a floating diffusion (FD) , a first conductive structure and a second conductive structure on the substrate to form a solid-state imaging device.
[0199] The first PD is similar to the first PD in FIG. 5 to FIG. 13, the TX is similar to the TX in FIG. 5 to FIG. 13, the FD is similar to the FD in FIG. 5 to FIG. 13, the first conductive structure is similar to the first conductive structure in FIG. 5 to FIG. 13, and the second conductive structure is similar to the second conductive structure in FIG. 5 to FIG. 13.
[0200] When the formed solid-state imaging device is a backside illuminated solid-state imaging device, the step 1620 includes: (1) forming a first substrate; (2) forming the first PD on the first substrate; (3) forming the first conductive structure, the second conductive structure, the TX, and the FD on the first PD; (4) forming a first metal wiring layer, which is disposed on a side of the first conductive structure, the second conductive structure, the TX, and the FD away from the first substrate; (5) flipping the first structure, which includes the first substrate, the first PD, the first conductive structure, the second conductive structure, the TX, the FD and the first metal wiring layer; and (6) bonding the first structure to the substrate formed in step 1610 to form the second structure. Among them, the substrate formed in step 1610 is disposed on the bottom layer, and is connected to the first metal wiring layer.
[0201] When the formed solid-state imaging device is a backside illuminated solid-state imaging device, the step 1620 also includes: forming a first material layer on the first conductive structure and / or the second conductive structure; or, forming a fourth material layer on the first conductive structure, and forming the first material layer on the second conductive structure; or, forming a fourth material layer on the first conductive structure, and forming a first material layer on the fourth material layer and the second conductive structure. The first material layers and / or the fourth material layers are described in FIG. 5 to FIG. 13.
[0202] When the formed solid-state imaging device is a backside illuminated solid-state imaging device, this method also includes: removing the first substrate from the second structure; forming a color filter layer on the second structure after removing the first structure, and the color filter layer is disposed on one side of the first PD away from the substrate; forming a microlens layer which is disposed on one side of the color filter layer away from the first PD. The color filter layer is similar to the color filter layer 340 in FIG. 3. The microlens layer is similar to the microlens layer 350 in FIG. 3.
[0203] When the formed solid-state imaging device is a frontside illuminated solid-state imaging device, the step 1620 includes: forming the first PD on the substrate; forming the TX, the FD, the first conductive structure and the second conductive structure on the first PD.
[0204] When the formed solid-state imaging device is a frontside illuminated solid-state imaging device, the step 1620 also includes: forming a first material layer on the first conductive structure and / or the second conductive structure; or, forming a fourth material layer on the first conductive structure, and forming the first material layer on the second conductive structure; or, forming a fourth material layer on the first conductive structure, and forming a first material layer on the fourth material layer and the second conductive structure. The first material layers and / or the fourth material layers are described in FIG. 5 to FIG. 13.
[0205] When the formed solid-state imaging device is a frontside illuminated solid-state imaging device, this method also includes: forming a color filter layer on the TX, the FD, the first conductive structure and the second conductive structure; forming a microlens layer on the color filter layer. The color filter layer is similar to the color filter layer 440 in FIG. 4. The microlens layer is similar to the microlens layer 450 in FIG. 4.
[0206] The embodiments of the present application do not limit the order in which the first conductive structure, the second conductive structure, the TX and the FD are formed on the first PD. For example, sequentially generating the first conductive structure, the second conductive structure, the TX, and the FD. Or, after forming the first conductive structure and / or the second conductive structure, the TX and / or FD can be formed. Or, after forming the TX and / or FD, the first conductive structure and / or second conductive structure can be formed.
[0207] Optionally, the first material is formed by doping the first ions into the photosensitive material, and the second material is formed by doping the second ions into the photosensitive material. The photosensitive material is any or more of the following: silicon germanium, silicon carbide, gallium arsenide, gallium phosphide, indium gallium arsenide, indium phosphide, indium arsenide, indium antimonide, semiconductor on insulator, etc. The types of the first ion and the second ion are different. For example, the first ion is p-type, and the second ion is n-type. Alternatively, the first ion is n-type and the second ion is p-type.
[0208] Optionally, as shown in FIG. 17, the solid-state imaging device in the embodiments of the present application is applied in at least one field: sports, beauty care, security, home applicances, agriculture, entertainment, transportation, medical, treatment, health care, etc.
[0209] Optionally, as shown in FIG. 18, when the solid-state imaging device in the embodiments of the present application is applied in a car 12100, the solid-state imaging device is disposed on the front, side, and rear of the car 12100. For example, the solid-state imaging device is disposed on the front bumper 12101 (or the hood) of the car 12100, and the imaging range of the solid-state imaging device is range 12111. And / or, the solid-state imaging device is disposed on the left mirror 12102 of the car 12100, and the imaging range of the solid-state imaging device is range 12112. And / or, the solid-state imaging device is disposed on the right mirror 12103 of the car 12100, and the imaging range of the solid-state imaging device is range 12113. And / or, the solid-state imaging device is disposed on the rear bumper 12104 (or the rear cover) of the car 12100, and the imaging range of the solid-state imaging device is range 12114. And / or, the solid-state imaging device is disposed on the front windshield (12105) of the car near the roof of the car.
[0210] The embodiment of the present application also provides an electronic device, which includes a solid-state imaging device provided in the above embodiments of the present application. Or, the electronic device includes a solid-state imaging system provided in the above embodiments of the present application.
[0211] The foregoing descriptions are merely specific implementations of this application, but are not intended to limit the protection scope of this application. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.
Claims
1.A solid-state imaging device, comprising: a substrate, a first photodiode (PD) , a transfer gate (TX) , a floating diffusion (FD) , a first conductive structure and a second conductive structure;wherein the first PD is disposed on an upper portion of the substrate;the TX, the FD, the first conductive structure, and the second conductive structure are disposed on the first PD, or, the TX, the FD, the first conductive structure, and the second conductive structure are disposed between the substrate and the first PD;the FD is disposed on one side of a first direction of the TX, wherein the first direction is parallel to an upper surface of the substrate;the first conductive structure is disposed on a side of the TX away from the FD, wherein the first conductive structure is connected to the first PD and the TX; andthe second conductive structure is disposed between the TX and the FD, wherein the second conductive structure is connected to the TX and the FD, and types of ions doped in the first PD, the first conductive structure, and the second conductive structure are the same.2.The device according to claim 1, wherein the first conductive structure is connected to the second conductive structure.3.The device according to claim 1 or 2, wherein the first conductive structure is a second photodiode.4.The device according to any one of claims 1-3, wherein the first conductive structure comprises a first part far from the TX and a second part near the TX, the first part and the second part of the first conductive structure have a same width in a second direction, or, the first part and the second part of the first conductive structure have different widths in a second direction, the second direction is parallel to the upper surface of the substrate, and the second direction is perpendicular to the first direction; and / orthe second conductive structure comprises a first part near the TX and a second part near the FD, the first part and the second part of the second conductive structure have a same width in a second direction, or, the first part and the second part of the second conductive structure have different widths in a second direction.5.The device according to any one of claims 1-4, wherein the first conductive structure comprises a first part far from the TX and a second part near the TX, the first part and the second part of the first conductive structure have a same width in a third direction, or, the first part and the second part of the first conductive structure have different widths in a third direction, the third direction is perpendicular to the upper surface of the substrate; and / orthe second conductive structure comprises a first part near the TX and a second part near the FD, the first part and the second part of the second conductive structure have a same width in a third direction, or, the first part and the second part of the second conductive structure have different widths in a third direction.6.The device according to any one of claims 1-5, wherein the first conductive structure and the second conductive structure have different widths in a second direction and / or a third direction, the second direction is parallel to the upper surface of the substrate, the second direction is perpendicular to the first direction, and the third direction is perpendicular to the first direction and the second direction.7.The device according to any one of claims 1-6, wherein an orthographic projection area of the TX on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the first conductive structure on the upper surface of the substrate; and / oran orthographic projection area of the TX on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the second conductive structure on the upper surface of the substrate.8.The device according to any one of claims 1-7, wherein an orthographic projection area of the FD on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the second conductive structure on the upper surface of the substrate.9.The device according to any one of claims 1-8, wherein a first distance and a second distance are different, the first distance is a distance between a first surface of the first conductive structure and the upper surface of the substrate, the first surface of the first conductive structure is a surface of the first conductive structure near the first PD, the second distance is a distance between a first surface of the second conductive structure and the upper surface of the substrate, and the first surface of the second conductive structure is a surface of the second conductive structure near the first PD.10.The device according to any one of claims 1-9, wherein a third distance and a fourth distance are different, the third distance is a distance between a second surface of the first conductive structure and the upper surface of the substrate, the second surface of the first conductive structure is a surface of the first conductive structure away from the first PD, the fourth distance is a distance between a second surface of the second conductive structure and the upper surface of the substrate, and the second surface of the second conductive structure is a surface of the second conductive structure away from the first PD.11.The device according to any one of claims 1-10, wherein a second distance and a fifth distance are different, the second distance is a distance between a first surface of the second conductive structure and the upper surface of the substrate, the first surface of the second conductive structure is a surface of the second conductive structure near the first PD, the fifth distance is a distance between a first surface of the FD and the upper surface of the substrate, and the first surface of the FD is a surface of the FD near the first PD.12.The device according to any one of claims 1-11, wherein the solid-state imaging device further comprises a first material layer, the first material layer is disposed on a side of the first conductive structure away from the first PD, types of ions doped in the first PD and the first material layer are different, or, ions are not doped in the first material layer; and / or, the first material layer is disposed on a side of the first conductive structure and the second conductive structure away from the first PD.13.The device according to any one of claims 1-12, wherein the TX comprises a protruded portion and at least one embedded portion, each embedded portion is disposed between the protruded portion and the first PD, and an angle is formed between each embedded portion and the protruded portion.14.The device according to claim 13, wherein the TX comprises embedded portions, at least two embedded portions of the TX have different sizes and / or shapes.15.The device according to claim 13 or 14, wherein an orthographic projection area of the protruded portion on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the first conductive structure on the upper surface of the substrate; and / or,an orthographic projection area of the protruded portion on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the second conductive structure on the upper surface of the substrate.16.The device according to any one of claims 13-15, wherein the solid-state imaging device further comprises a first material layer, the first material layer is disposed between the first conductive structure and the protruded portion, types of ions doped in the first PD and the first material layer are different, or, ions are not doped in the first material layer; and / or,the first material layer is disposed between the first conductive structure and the protruded portion, as well as between the second conductive structure and the protruded portion.17.The device according to claim 16, wherein an orthographic projection area of the protruded portion on the upper surface of the substrate partially or completely overlaps with an orthographic projection area of the first material layer on the upper surface of the substrate.18.The device according to any one of claims 1-17, wherein a blooming path is controlled by a bias of the TX, the blooming path is a charge transfer path starting from the first PD and sequentially passing through the first conductive structure, the TX, and second conductive structure to the FD, the bias of the TX is a voltage greater than or equal to -2 volt (V) , and the bias of the TX is a voltage less than or equal to +1 V during an exposure.19.A method of making a solid-state imaging device, comprising:forming a substrate; andforming a first photodiode (PD) , a transfer gate (TX) , a floating diffusion (FD) , a first conductive structure and a second conductive structure on the substrate, to form a solid-state imaging device as claimed in any one of claims 1-18.20.A solid-state imaging device, comprising: a solid-state imaging device as claimed in any one of claims 1 to 18, a control circuit and a signal processing circuit, wherein the control circuit is configured to control the pixel array in the solid-state imaging device, and the signal processing circuit is configured to process image data obtained from the solid-state imaging device.21.An electronic device, comprising:a solid-state imaging device as claimed in claim 20.
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