Light detection device

Abstract

This light detection device comprises: a first pixel in which a first photoelectric conversion element that converts light into an electric charge is disposed on a first surface side of a substrate; a pixel separation region that is provided so as to extend along the periphery of a side surface of the first pixel and optically and electrically separates the first pixel from the surroundings; and a first transfer transistor that is disposed on a second surface side of the substrate on the side opposite to the first surface so as to overlap the first pixel. A first main electrode, which is one of main electrodes of the first transfer transistor, is electrically connected to the first photoelectric conversion element. In addition, in the light detection device, a part of the pixel separation region in the extension direction is divided on at least the second surface side of the substrate, and a second main electrode, which is the other main electrode of the first transfer transistor, is disposed at the division site.

Description

Photodetector

[0001] The present disclosure relates to a light detection device.

[0002] Patent Document 1 discloses a solid-state imaging device. The solid-state imaging device includes a photoelectric conversion unit formed for each pixel and a pixel separation unit that separates the photoelectric conversion units of each pixel. The photoelectric conversion unit and the pixel separation unit are each formed on a silicon (Si) substrate. The solid-state imaging device is constructed as a back-illuminated type, and pixel transistors are formed within each pixel on the surface of the Si substrate facing the light incident surface. The pixel transistors include, for example, transfer transistors.

[0003] WO2018 / 139279 publication

[0004] In solid-state imaging devices, the pixel area tends to decrease as the number of pixels increases, and therefore it is desirable to reduce the ratio of the area occupied by pixel transistors arranged in pixels to the pixel area.

[0005] A photodetector according to a first embodiment of the present disclosure includes a first pixel, the first pixel having a first photoelectric conversion element that converts light into an electric charge, disposed on a first surface side of a substrate, a pixel isolation region that extends along a periphery of a side surface of the first pixel and optically and electrically isolates the first pixel from the surrounding area, and a first transfer transistor, the first pixel having a pair of first main electrodes that are electrically connected to the first photoelectric conversion element, disposed on a second surface side of the substrate opposite the first surface. Additionally, in the photodetector, a portion of the pixel isolation region in the extension direction is divided at least on the second surface side of the substrate, and the other second main electrode of the pair of first transfer transistors is disposed at the divided location.

[0006] A photodetector according to a second embodiment of the present disclosure is the photodetector according to the first embodiment, further comprising: a first well region in which a first transfer transistor is disposed on the second surface side of the substrate; and a first well contact region of the same conductivity type as the first well region and electrically connected to the first well region, the first well contact region being disposed at the separated location, at least on the second surface side of the substrate, where another part of the extension direction of the pixel isolation region is separated.

[0007] A photodetector according to a third embodiment of the present disclosure is the photodetector according to the second embodiment, further comprising: a second pixel adjacent to the first pixel on the first surface side of a substrate, the second pixel including a second photoelectric conversion element configured to convert light into an electric charge; a pixel isolation region extending along a periphery of a side surface of the second pixel and optically and electrically isolating the second pixel from the surrounding area; and a second transfer transistor disposed on the second surface side of the substrate so as to overlap the second pixel, the second transfer transistor having a third main electrode electrically connected to the second photoelectric conversion element. In addition, in the photodetector, a portion of the pixel isolation region in the extension direction is divided at least on the second surface side of the substrate, and the other fourth main electrode of the pair of second transfer transistors is disposed at the divided location.

[0008] A photodetector according to a fourth embodiment of the present disclosure is the photodetector according to the third embodiment, further comprising: a second well region in which a second transfer transistor is disposed on the second surface side of the substrate; and a second well contact region of the same conductivity type as the second well region and electrically connected to the second well region, the second well contact region being disposed at the separated location, at least on the second surface side of the substrate, where another part of the extension direction of the pixel isolation region is separated.

[0009] In a photodetector according to a fifth embodiment of the present disclosure, the first pixel and the second pixel in the photodetector according to the fourth embodiment can constitute a phase difference detection pixel.

[0010] In a photodetector according to a sixth embodiment of the present disclosure, in the photodetector according to the fifth embodiment, another portion in the extension direction of the pixel isolation region arranged between the first pixel and the second pixel is divided, and an overflow path region that flows excess charge from one of the first photoelectric conversion element and the second photoelectric conversion element to the other is arranged at this division point.

[0011] FIG. 1 is a diagram illustrating the overall system configuration of a photodetector according to a first embodiment of the present disclosure. FIG. 2 is a circuit diagram of a pixel and a pixel circuit of the photodetector shown in FIG. 1. FIG. 3 is a specific plan view of the pixel shown in FIG. 2. FIG. 4 is a longitudinal cross-sectional view of the photodetector and pixel shown in FIG. 3 (a cross-sectional view taken along the A-A section line shown in FIG. 3). FIG. 5 is a longitudinal cross-sectional view of a main part of the photodetector and pixel shown in FIG. 3 (a cross-sectional view taken along the B-B section line shown in FIG. 3). FIG. 6 is a longitudinal cross-sectional view of a main part of the photodetector and pixel shown in FIG. 3 (a cross-sectional view taken along the C-C section line shown in FIG. 3). FIG. 7 is a circuit diagram corresponding to FIG. 2 of a pixel and a pixel circuit of a photodetector according to a second embodiment of the present disclosure. FIG. 8 is a circuit diagram corresponding to FIG. 2 of a pixel and a pixel circuit of a photodetector according to a third embodiment of the present disclosure. FIG. 9 is a circuit diagram corresponding to FIG. 2 of a pixel and a pixel circuit of a photodetector according to a fourth embodiment of the present disclosure. FIG. 10 is a plan view of a pixel of a photodetector according to a fifth embodiment of the present disclosure, corresponding to FIG. 3 . FIG. 11 is a plan view of a pixel of a photodetector according to a sixth embodiment of the present disclosure, corresponding to FIG. 3 . FIG. 12 is a longitudinal cross-sectional view of the pixel shown in FIG. 11 (a cross-sectional view taken along the D-D section line shown in FIG. 11 ). FIG. 13 is a plan view of a pixel of a photodetector according to a seventh embodiment of the present disclosure, corresponding to FIG. 3 . FIG. 14 is a longitudinal cross-sectional view of the pixel shown in FIG. 13 (a cross-sectional view taken along the E-E section line shown in FIG. 13 ). FIG. 15 is a plan view of a pixel of a photodetector according to an eighth embodiment of the present disclosure, corresponding to FIG. 3 . FIG. 16 is a longitudinal cross-sectional view of the pixel shown in FIG. 15 (a cross-sectional view taken along the F-F section line shown in FIG. 15 ). FIG. 17 is a plan view of a pixel of a photodetector according to a ninth embodiment of the present disclosure, corresponding to FIG. 3 . FIG. 18 is a plan view of a pixel of a photodetector according to a tenth embodiment of the present disclosure, corresponding to FIG. 3 . Fig. 19 is a longitudinal cross-sectional configuration diagram of the pixel shown in Fig. 18 (a cross-sectional view taken along the G-G cutting line shown in Fig. 18). Fig. 20 is a planar configuration diagram of a pixel of a photodetector according to an eleventh embodiment of the present disclosure, corresponding to Fig. 3. Fig. 21 is a longitudinal cross-sectional configuration diagram of the pixel shown in Fig. 20 (a cross-sectional view taken along the H-H cutting line shown in Fig. 20).FIG. 22 is a plan view of a pixel of a photodetector according to a twelfth embodiment of the present disclosure, corresponding to FIG. 3 . FIG. 23 is a longitudinal cross-sectional view of the pixel shown in FIG. 22 (a cross-sectional view taken along the II section line shown in FIG. 22 ). FIG. 24 is a plan view of a pixel of a photodetector according to a thirteenth embodiment of the present disclosure, corresponding to FIG. 3 . FIG. 25 is a longitudinal cross-sectional view of the pixel shown in FIG. 24 (a cross-sectional view taken along the J-J section line shown in FIG. 24 ). FIG. 26 is a plan view of a pixel of a photodetector according to a fourteenth embodiment of the present disclosure, corresponding to FIG. 3 . FIG. 27 is a plan view of a pixel of a photodetector according to a fifteenth embodiment of the present disclosure, corresponding to FIG. 3 . FIG. 28 is a plan view of a pixel of a photodetector according to a sixteenth embodiment of the present disclosure, corresponding to FIG. 3 . FIG. 29 is a plan view of a pixel of a photodetector according to a seventeenth embodiment of the present disclosure, corresponding to FIG. 3 . FIG. 30 is a plan view of a pixel of a photodetector according to an eighteenth embodiment of the present disclosure, corresponding to FIG. 3 . FIG. 30 is a longitudinal cross-sectional configuration diagram of the pixel shown in FIG. 30 (a cross-sectional view taken along the K-K section line shown in FIG. 30). FIG. 32 is a plan configuration diagram corresponding to FIG. 3 of a pixel of a photodetector according to a nineteenth embodiment of the present disclosure. FIG. 33 is a plan configuration diagram corresponding to FIG. 3 of a pixel of a photodetector according to a twentieth embodiment of the present disclosure. FIG. 34 is a longitudinal cross-sectional configuration diagram of the pixel shown in FIG. 33 (a cross-sectional view taken along the L-L section line shown in FIG. 33). FIG. 35 is a plan configuration diagram corresponding to FIG. 3 of a pixel of a photodetector according to a twenty-first embodiment of the present disclosure. FIG. 36 is a longitudinal cross-sectional configuration diagram of the pixel shown in FIG. 35 (a cross-sectional view taken along the M-M section line shown in FIG. 35). FIG. 37 is a plan configuration diagram corresponding to FIG. 3 of a pixel of a photodetector according to a twenty-second embodiment of the present disclosure. FIG. 38 is a plan configuration diagram corresponding to FIG. 3 of a pixel of a photodetector according to a twenty-third embodiment of the present disclosure. Fig. 39 is a plan view of a pixel of a photodetector according to a twenty-fourth embodiment of the present disclosure, corresponding to Fig. 3. Fig. 40 is a plan view of a pixel of a photodetector according to a twenty-fifth embodiment of the present disclosure, corresponding to Fig. 3.

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order. 1. First Embodiment The first embodiment will describe a first example in which the present technology is applied to a photodetector. The first embodiment will describe the overall system configuration of the photodetector, the circuit configuration of pixels and pixel circuits, the planar configuration of pixels, and the longitudinal cross-sectional configuration of pixels. 2. Second Embodiment The second embodiment will describe a second example in which the circuit configuration of pixels and pixel circuits is changed in the photodetector according to the first embodiment. 3. Third Embodiment The third embodiment will describe a third example in which the circuit configuration of pixels and pixel circuits is changed in the photodetector according to the first embodiment. 4. Fourth Embodiment The fourth embodiment will describe a fourth example in which the circuit configuration of pixels and pixel circuits is changed in the photodetector according to the first embodiment. 5. Fifth Embodiment The fifth embodiment will describe a fifth example in which the planar structure of pixels and the longitudinal cross-sectional configuration of pixels are changed in the photodetector according to the first embodiment. 6. Sixth Embodiment The sixth embodiment describes a sixth example in which the planar structure of pixels and the longitudinal cross-sectional configuration of pixels are changed in the photodetector according to the first embodiment. 7. Seventh Embodiment The seventh embodiment describes a seventh example in which the planar structure of pixels and the longitudinal cross-sectional configuration of pixels are changed in the photodetector according to the sixth embodiment. 8. Eighth Embodiment The eighth embodiment describes an eighth example in which the planar structure of pixels and the longitudinal cross-sectional configuration of pixels are changed in the photodetector according to the first embodiment. 9. Ninth Embodiment The ninth embodiment describes a ninth example in which the photodetector according to the fifth embodiment is combined with the photodetector according to the eighth embodiment. 10. Tenth Embodiment The tenth embodiment describes a tenth example in which the planar structure of pixels and the longitudinal cross-sectional configuration of pixels are changed in the photodetector according to the first embodiment. 11. Eleventh Embodiment The eleventh embodiment describes an eleventh example in which the photodetector according to the eighth embodiment is combined with the photodetector according to the tenth embodiment. 12. Twelfth Embodiment In the twelfth embodiment, a twelfth example will be described in which the planar structure of the pixel and the vertical cross-sectional configuration of the pixel are changed in the photodetector according to the tenth embodiment.13. Thirteenth Embodiment The thirteenth embodiment describes a thirteenth example in which the photodetector according to the eleventh embodiment is combined with the photodetector according to the twelfth embodiment. 14. Fourteenth Embodiment The fourteenth embodiment describes a fourteenth example in which the planar structure of pixels and the longitudinal cross-sectional configuration of pixels are changed in the photodetector according to the tenth embodiment. 15. Fifteenth Embodiment The fifteenth embodiment describes a fifteenth example in which the planar structure of pixels and the longitudinal cross-sectional configuration of pixels are changed in the photodetector according to the fourteenth embodiment. 16. Sixteenth Embodiment The sixteenth embodiment describes a sixteenth example in which the planar structure of pixels and the longitudinal cross-sectional configuration of pixels are changed in the photodetector according to the fifteenth embodiment. 17. Seventeenth Embodiment The seventeenth embodiment describes a seventeenth example in which the planar structure of pixels and the longitudinal cross-sectional configuration of pixels are changed in the photodetector according to the sixteenth embodiment. 18. 18th Embodiment The 18th embodiment describes an 18th example in which the planar structure of a pixel and the longitudinal cross-sectional configuration of a pixel are changed in the photodetector according to the 14th embodiment. 19. 19th Embodiment The 19th embodiment describes a 19th example in which the planar structure of a pixel and the longitudinal cross-sectional configuration of a pixel are changed in the photodetector according to the 18th embodiment. 20. 20th Embodiment The 20th embodiment describes a 20th example in which the planar structure of a pixel and the longitudinal cross-sectional configuration of a pixel are changed in the photodetector according to the 10th embodiment. 21. 21st Embodiment The 21st embodiment describes a 21st example in which the planar structure of a pixel and the longitudinal cross-sectional configuration of a pixel are changed in the photodetector according to the 20th embodiment. 22. 22nd Embodiment The 22nd embodiment describes a 22nd example in which the planar structure of a pixel and the longitudinal cross-sectional configuration of a pixel are changed in the photodetector according to the 21st embodiment. 23. 21st Embodiment The 23rd embodiment describes a 23rd example in which the planar structure of the pixels and the vertical cross-sectional configuration of the pixels are changed in the photodetector device according to the 22nd embodiment. 24. 24th Embodiment The 24th embodiment describes a 24th example in which the planar structure of the pixels and pixel circuits are changed in the photodetector device according to the first embodiment. 25. 25th Embodiment The 25th embodiment describes a 25th example in which the planar structure of the pixels and pixel circuits is changed in the photodetector device according to the 14th embodiment.26. Other embodiments.

[0013] 1. First Embodiment A photodetector 1 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 6. FIG.

[0014] Here, the arrow X direction shown as appropriate in the drawings indicates one planar direction of the photodetector 1 placed on a flat surface for convenience. The arrow Y direction indicates another planar direction perpendicular to the arrow X direction. The arrow Z direction indicates an upward direction perpendicular to the arrow X and arrow Y directions. In other words, the arrow X direction, arrow Y direction, and arrow Z direction exactly correspond to the X-axis direction, Y-axis direction, and Z-axis direction, respectively, of a three-dimensional coordinate system. Note that these directions are shown to facilitate understanding of the explanation and do not limit the directions of the present technology.

[0015] [Configuration of Photodetector 1] (1) Overall Configuration of Photodetector 1 Fig. 1 shows an example of the overall system configuration of a photodetector 1 according to a first embodiment. The photodetector 1 is constructed using a back-illuminated solid-state imaging device or includes a back-illuminated solid-state imaging device. Here, the photodetector 1 is constructed as a CMOS (Complementary Metal Oxide Semiconductor) solid-state imaging device. The photodetector 1 detects light L (see Fig. 4) incident from outside, converts the detected light L into electric charges, and generates an image such as a still image or a video based on the converted electric charges.

[0016] The photodetector 1 includes a pixel region (pixel array portion) 100 and peripheral circuits. The pixel region 100 includes a plurality of pixels 10 regularly arranged two-dimensionally within a plane in the directions of arrows X and Y.

[0017] As will be explained later, the pixel 10 includes a photoelectric conversion element PD (see, for example, FIG. 2) and a transfer transistor TR (see, for example, FIG. 2). The photoelectric conversion element PD is configured, for example, by a photodiode. The photoelectric conversion element PD converts light L (see FIG. 4) incident from the outside into electric charges. The transfer transistor TR transfers the electric charges converted by the photoelectric conversion element PD. In addition, a pixel circuit 20 (see FIG. 2) is electrically connected to the pixel 10. The pixel circuit 20 reads out the electric charges converted in the pixel 10.

[0018] The peripheral circuits are configured to include a vertical drive circuit VD, a column signal processing circuit CS, a horizontal drive circuit HD, an output circuit Out, a control circuit CC, and the like.

[0019] The control circuit CC receives an input clock and data instructing the operation mode, etc., and outputs data such as internal information of the photodetector 1. That is, the control circuit CC generates clock signals and control signals that serve as the basis for the operation of the vertical drive circuit VD, column signal processing circuit CS, horizontal drive circuit HD, etc., based on a vertical synchronization signal, a horizontal synchronization signal, and a master clock. These signals are then input to the vertical drive circuit VD, column signal processing circuit CS, horizontal drive circuit HD, etc.

[0020] The vertical drive circuit VD is configured, for example, by a shift register. The vertical drive circuit VD selects a pixel drive line Ld and supplies a pulse to the selected pixel drive line Ld to drive the pixels 10. The pixels 10 are driven row by row. That is, the vertical drive circuit VD sequentially selects and scans each pixel 10 in the pixel region 100 row by row in the vertical direction. Signal charges generated in accordance with the amount of light received by the photoelectric conversion element PD of each pixel 10 are supplied as pixel signals to a column signal processing circuit CS via a vertical signal line VSL.

[0021] The column signal processing circuit CS is arranged, for example, for each column of pixels 10. The column signal processing circuit CS performs signal processing such as noise removal on signals output from one row of pixels 10 for each pixel column. That is, the column signal processing circuit CS performs signal processing such as CDS (Correlated Double Sampling) to remove fixed pattern noise specific to the pixels 10, signal amplification, and AD (Analog-Digital) conversion. A horizontal selection switch (not shown) is connected between the output stage of the column signal processing circuit CS and the horizontal signal 0 line Lh.

[0022] The horizontal drive circuit HD is configured by, for example, a shift register, and sequentially outputs horizontal scanning pulses to select each of the column signal processing circuits CS in turn, and outputs pixel signals from each of the column signal processing circuits CS to the horizontal signal line Lh.

[0023] The output circuit Out processes and outputs signals sequentially supplied from each of the column signal processing circuits CS through the horizontal signal line Lh. For example, the output circuit Out may perform only buffering, or may perform black level adjustment, column variation correction, various digital signal processing, etc. The input / output terminal In exchanges signals between the photodetector 1 and the outside.

[0024] (2) Circuit Configuration of Pixel 10 and Pixel Circuit 20 Fig. 2 shows an example of the circuit configuration of the pixel 10 and pixel circuit 20 of the photodetector device 1. In the first embodiment, four pixels 10 are electrically connected to one pixel circuit 20, and the four pixels 10 share one pixel circuit 20. In other words, the electric charges converted from light L in each of the four pixels 10 are read out in the one pixel circuit 20. The four pixels 10 sharing this one pixel circuit 20 constitute a unit pixel.

[0025] To facilitate understanding of the description, one pixel 10 of the unit pixel is designated by the symbol "10,1." The pixel 10 adjacent to pixel 10,1 in the direction indicated by the arrow X is designated by the symbol "10,3." The pixel 10 adjacent to pixel 10,1 in the direction indicated by the arrow Y is designated by the symbol "10,2." The pixel 10 adjacent to pixel 10,2 in the direction indicated by the arrow X is designated by the symbol "10,4." Therefore, the unit pixel is configured as a "2x2" pixel array in which two pixels, 10,1 and 10,3, are arranged in the direction indicated by the arrow X, and two pixels, 10,2 and 10,4, are arranged in the direction indicated by the arrow Y. When it is not particularly necessary to distinguish between pixels 10,1 to 10,4, they will be simply referred to as "pixel 10."

[0026] Furthermore, in the first embodiment, the pixels 10 are configured as phase difference detection pixels. In the photodetection device 1 according to the first embodiment, all or some of the pixels 10 in the pixel region 100 are configured as phase difference detection pixels. That is, the pixels 10 are used as phase difference detection pixels when detecting the phase difference of light L, and are used as normal pixels in other cases.

[0027] The pixel 10,1 of the unit pixel includes a pixel 10L and a pixel 10R arranged adjacent to the pixel 10L in the direction of the arrow X. Similarly, each of the pixels 10,2 to 10,4 includes a pixel 10L and a pixel 10R arranged adjacent to the pixel 10L in the direction of the arrow X.

[0028] Each pixel 10L of pixels 10.1 to 10.4 includes a photoelectric conversion element PDL and a transfer transistor TRL, which are configured as a series circuit. Specifically, the photoelectric conversion element PDL is configured as a photodiode. The photodiode includes an anode region and a cathode region. Meanwhile, the transfer transistor TRL is formed of an insulated gate field effect transistor (IGFET). The IGFET includes a pair of main electrodes (a source region and a drain region) and a gate electrode. The anode region of the photoelectric conversion element PDL is electrically connected to a reference voltage GND. The cathode region is electrically connected to one main electrode of the transfer transistor TRL. The other main electrode of the transfer transistor TRL is electrically connected to one end of a floating diffusion FD. A control signal for controlling conduction or non-conduction is input to the gate electrode.

[0029] Similarly, each pixel 10R of pixels 10.1 to 10.4 includes a photoelectric conversion element PDR and a transfer transistor TRR, configured as a series circuit of the two. More specifically, the photoelectric conversion element PDR is configured as a photodiode. The photodiode includes an anode region and a cathode region. Meanwhile, the transfer transistor TRR is formed as an IGFET. The IGFET includes a pair of main electrodes (a source region and a drain region) and a gate electrode. The anode region of the photoelectric conversion element PDR is electrically connected to a reference voltage GND. The cathode region is electrically connected to one main electrode of the transfer transistor TRR. The other main electrode of the transfer transistor TRR is electrically connected to one end of a floating diffusion FD. A control signal for controlling conduction or non-conduction is input to the gate electrode.

[0030] When it is not particularly necessary to distinguish between the pixels 10L and 10R, they will be simply referred to as "pixels 10." Furthermore, when it is not particularly necessary to distinguish between the photoelectric conversion elements PDL and PDR, they will be simply referred to as "photoelectric conversion elements PD." Furthermore, when it is not particularly necessary to distinguish between the transfer transistors TRL and TRR, they will be simply referred to as "transfer transistors TR."

[0031] Here, the pixel 10L corresponds to a “first pixel” according to the present technology, the pixel 10R corresponds to a “second pixel” according to the present technology, the photoelectric conversion element PDL corresponds to a “first photoelectric conversion element” according to the present technology, and the photoelectric conversion element PDR corresponds to a “second photoelectric conversion element” according to the present technology.

[0032] Furthermore, the transfer transistor TRL corresponds to a "first transfer transistor" according to the present technology. One main electrode of the pair of transfer transistors TRL corresponds to a "first main electrode" according to the present technology, and the other main electrode corresponds to a "second main electrode" according to the present technology. Furthermore, the transfer transistor TRR corresponds to a "second transfer transistor" according to the present technology. One main electrode of the pair of transfer transistors TRR corresponds to a "third main electrode" according to the present technology, and the other main electrode corresponds to a "fourth main electrode" according to the present technology.

[0033] Although the detailed structure will be described later, in the first embodiment, the transfer transistor TR is configured as a vertical transistor, that is, a vertical IGFET.

[0034] The pixel circuit 20 is constructed of a plurality of pixel transistors. Here, the pixel transistors include a reset transistor 2, an amplifier transistor AMP, and a selection transistor SEL. Each of the pixel transistors is constructed of a lateral IGFET.

[0035] One main electrode (e.g., a source region) of the reset transistor RST is electrically connected to the other end of the floating diffusion FD. The other main electrode is electrically connected to a power supply voltage VDD. A reset signal is input to the gate electrode. When the reset transistor RST is turned on, it resets the floating diffusion FD to a potential equivalent to the power supply voltage VDD.

[0036] One main electrode of the amplification transistor AMP is electrically connected to one main electrode of the selection transistor SEL. The other main electrode is electrically connected to the power supply voltage VDD. One main electrode of the reset transistor RST and the other end of the floating diffusion FD are electrically connected to the gate electrode. The amplification transistor AMP constitutes a source follower amplifier. In other words, the amplification transistor AMP generates a pixel signal according to the charge transferred through the floating diffusion FD.

[0037] The other main electrode of the selection transistor SEL is electrically connected to a vertical signal line VSL. A selection signal is input to the gate electrode of the selection transistor SEL. The selection transistor SEL outputs a generated pixel signal to the vertical signal line VSL.

[0038] Note that a floating diffusion (FD) conversion gain switching transistor may be included in the pixel circuit 20. In this case, one main electrode of the FD conversion gain switching transistor is electrically connected to the floating diffusion FD, and the other main electrode is electrically connected to one main electrode (for example, a source region) of the reset transistor RST.

[0039] (3) Schematic Device Configuration of Photodetector 1 Although detailed illustration is omitted here, the photodetector 1 according to the first embodiment employs a three-layer laminated structure in which a first substrate 1A, a second substrate 1B, and a third substrate 1C are laminated in this order from the incident direction of light L (see FIG. 4). Note that the photodetector 1 may employ a two-layer laminated structure in which the first substrate 1A and the second substrate 1B are combined into a single substrate, and the third substrate 1C is laminated on this substrate (see the photodetector 1 according to the twenty-fourth or twenty-fifth embodiment).

[0040] A pixel region 100 is disposed over substantially the entire area of ​​the first substrate 1A (see FIG. 1). That is, the first substrate 1A is provided with a photoelectric conversion element PD and a transfer transistor TR that constitute a pixel 10. The first substrate 1A constitutes a photodetection surface that serves as an imaging surface for capturing an image.

[0041] The pixel circuit 20 is disposed on the second substrate 1B (see FIG. 2). That is, the amplifying transistor AMP, the reset transistor RST, and the selection transistor SEL that constitute the pixel circuit 20 are disposed on the second substrate 1B. In the case of a photodetector 1 having a two-layer stacked structure, the pixel circuit 20 is disposed on a substrate that combines the first substrate 1A and the second substrate 1B.

[0042] The third substrate 1C is provided with peripheral circuits (see FIG. 1). As described above, the peripheral circuits include the vertical drive circuit VD, the column signal processing circuit CS, the horizontal drive circuit HD, the output circuit Out, and the control circuit CC.

[0043] (4) Specific Device Configuration of the Photodetector 1 FIG. 3 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. FIG. 4 shows an example of a longitudinal cross-sectional configuration of the pixel 10 taken along the A-A section line shown in FIG. 3. FIG. 5 shows an example of a longitudinal cross-sectional configuration of a main part of the pixel 10 taken along the B-B section line shown in FIG. 3. FIG. 6 shows an example of a longitudinal cross-sectional configuration of a main part of the pixel 10 taken along the C-C section line shown in FIG. 3. Note that FIG. 3 shows the respective components of the second substrate 1B and the third substrate 1C in a simplified manner. Also, FIGS. 4 and 5 omit the optical lens 9 and the respective components of the second substrate 1B and the third substrate 1C.

[0044] 3 to 6, the pixel 10 and the pixel region 100 in which a plurality of pixels 10 are arranged are disposed on the first base 1A. The first base 1A includes a semiconductor substrate 30 and a wiring layer 31.

[0045] The semiconductor substrate 30 is, for example, a single-crystal silicon (Si) substrate. The semiconductor substrate 30 has a first surface 30A on the side indicated by the arrow Z and a second surface 30B opposite to the arrow Z, facing the first surface 30A. Here, n-type is defined as the "first conductivity type," and p-type, which is the opposite conductivity type to n-type, is defined as the "second conductivity type." A p-type well region 302 is disposed at least on the second surface 30B side of the semiconductor substrate 30. The p-type well region 302 of the semiconductor substrate 30 may be replaced with an intrinsic semiconductor (i-type semiconductor region).

[0046] The wiring layer 31 is laminated on the second surface 30B of the semiconductor substrate 30. The wiring layer 31 includes an insulator 7, and a signal wiring 71 and a power wiring 72 that are disposed so as to penetrate the insulator 7 in the thickness direction. The insulator 7 is made of, for example, silicon oxide (SiO ２ The signal wiring 71 and the power supply wiring 72 are each formed of a metal material such as tungsten (W).

[0047] (4-2) Configuration of Pixel 10 As shown in FIGS. 3 to 6, among the pixels 10 of the unit pixel, pixel 10,1 includes pixel 10L and pixel 10R that constitute a phase difference detection pixel. When viewed from the arrow Z direction or the opposite direction (hereinafter simply referred to as "in a plan view"), pixel 10R is formed in a shape that is line-symmetrical with respect to pixel 10L, with center line CL1 that extends in the arrow Y direction through the middle position between pixel 10L and pixel 10R as the center. Center line CL1 exactly coincides with the B-B cutting line. In other words, pixel 10R is formed in a shape that is optically symmetrical with respect to pixel 10L.

[0048] Each pixel 10L includes a photoelectric conversion element PDL and a transfer transistor TRL. In this example, the pixel 10L has a rectangular planar shape in which the length in the direction indicated by the arrow Y is longer than the length in the direction indicated by the arrow X. A pixel isolation region 4 extends along the periphery of the side surface of the pixel 10L. The specific configuration of the pixel isolation region 4 will be described later.

[0049] The photoelectric conversion element PDL is disposed on the first surface 30A side of the semiconductor substrate 30 in the first base body 1A. The photoelectric conversion element PDL is formed by a pn junction between a p-type well region 302 serving as an anode region and an n-type semiconductor region 301 serving as a cathode region.

[0050] The transfer transistor TRL is disposed in the first base 1A on the second surface 30B side of the semiconductor substrate 30. The transfer transistor TRL includes a gate electrode 52, a gate insulating film 53, and a pair of main electrodes.

[0051] The gate insulating film 53 is formed along at least the sidewall of the trench 51, which extends from the second surface 30B in the depth direction of the p-type well region 302 and reaches the n-type semiconductor region 301. The gate insulating film 53 is made of, for example, SiO ２ The insulating layer is made of one or more insulating materials selected from silicon nitride (SiN) and silicon oxynitride (SiON).

[0052] The gate electrode 52 is buried in the trench 51 with a gate insulating film 53 interposed therebetween, and a portion of the gate electrode 52 extends onto the second surface 30 B. The gate electrode 52 is made of, for example, polycrystalline Si.

[0053] One of the pair of main electrodes is formed of an n-type semiconductor region 301 as a cathode region of the photoelectric conversion element PDL. The other main electrode will be described later.

[0054] The pixel 10R includes a photoelectric conversion element PDR and a transfer transistor TRR. Similar to the pixel 10L, the pixel 10R has a rectangular planar shape in which the length in the direction of the arrow Y is longer than the length in the direction of the arrow X in a plan view. A pixel isolation region 4 extends along the periphery of the side surface of the pixel 10R. The pixel isolation region 4 extending between the pixel 10L and the pixel 10R is shared by both the pixel 10L and the pixel 10R. Similarly, the specific configuration of the pixel isolation region 4 will be described later.

[0055] Like the photoelectric conversion element PDL, the photoelectric conversion element PDR is disposed on the first surface 30A side of the p-type well region 302. The photoelectric conversion element PDR is formed by a pn junction between the p-type well region 302 as an anode region and the n-type semiconductor region 301 as a cathode region.

[0056] Like the transfer transistor TRL, the transfer transistor TRR is disposed on the second surface 30B side of the p-type well region 302. The transfer transistor TRR includes a gate electrode 52, a gate insulating film 53, and a pair of main electrodes.

[0057] The gate insulating film 53 extends from the second surface 30B in the depth direction of the p-type well region 302 and is formed along at least the sidewall of a trench 51 formed to reach the n-type semiconductor region 301. The gate electrode 52 is buried in the trench 51 with the gate insulating film 53 interposed therebetween, and a portion of the gate electrode 52 extends to the second surface 30B. Of the pair of main electrodes, one main electrode is formed by the n-type semiconductor region 301 as a cathode region of the photoelectric conversion element PDR. The other main electrode will be described later.

[0058] (4-3) Configuration of Pixel Isolation Region 4 The pixel isolation region 4 optically and electrically isolates each of the pixels 10L and 10R from the surroundings. In the first embodiment, the pixel isolation region 4 includes an isolation groove 401, an insulator 402, a buried body 403, and a further insulator 404.

[0059] The isolation trench 401 of the pixel isolation region 4 is formed as a trench penetrating from the first surface 30A to the second surface 30B of the semiconductor substrate 30. The insulator 402 is disposed along the inner wall of the isolation trench 401. The insulator 402 is made of, for example, SiO ２ The buried body 403 is buried inside the separation groove 401 with an insulator 402 interposed therebetween. Here, the buried body 403 is made of, for example, polycrystalline Si. The insulator 404 is buried on the second surface 30B side of the separation groove 401. The insulator 404 is made of, for example, SiO ２ It is formed by

[0060] Furthermore, in the semiconductor substrate 30, a p-type semiconductor region 303 is disposed along the isolation trench 401 of the pixel isolation region 4. The p-type semiconductor region 303 is used as a pinning region that effectively suppresses or prevents the generation of dark current.

[0061] The pixel isolation region 4 surrounding the side surface of the pixel 10L has a separation portion 41, where a portion of the pixel isolation region 4 in the extension direction (the upper right portion of the pixel 10L in FIG. 3 ) is separated. The separation portion 41 is a region on the second surface 30B side of the semiconductor substrate 30 where the pixel isolation region 4 or a portion of the pixel isolation region 4 (e.g., the insulator 404) is not provided, and is formed as a semiconductor region such as a p-type well region 302 or an intrinsic semiconductor. An n-type semiconductor region 54 is provided in the separation portion 41. The n-type semiconductor region 54 is used as the other main electrode of the transfer transistor TRL. The n-type semiconductor region 54 is formed by activating n-type impurities implanted by, for example, ion implantation. A signal wiring 71 disposed directly above the n-type semiconductor region 54 is electrically connected to the n-type semiconductor region 54.

[0062] Furthermore, the dividing point 41 is shared by the pixel isolation region 4 surrounding the pixel 10,1 and the pixel isolation region 4 surrounding the pixel 10,2 adjacent to it in the direction of the arrow Y. In other words, the other main electrode (n-type semiconductor region 54) of the transfer transistor TRL is shared by the pixel 10L of the pixel 10,1 and the pixel 10L of the pixel 10,2.

[0063] Furthermore, in the pixel isolation region 4 surrounding the side periphery of the pixel 10L, a separation portion 42 is provided, in which another portion of the pixel isolation region 4 in the extension direction (the lower left portion of the pixel 10L in FIG. 3 ) is separated. Similar to the separation portion 41, the separation portion 42 is formed as a semiconductor region on the second surface 30B side of the semiconductor substrate 30 where the pixel isolation region 4 or a portion of the pixel isolation region 4 is not provided. A p-type well contact region 6 is provided in the separation portion 42. The p-type well contact region 6 is electrically connected to the p-type well region 302. The p-type well contact region 6 is formed by activating p-type impurities implanted by, for example, ion implantation. The p-type well contact region 6 is electrically connected to a power supply wiring 72 provided directly above it.

[0064] Meanwhile, in the pixel isolation region 4 surrounding the side surface of the pixel 10R, a dividing portion 41 is provided, in which a portion of the pixel isolation region 4 in the extension direction (the upper left portion of the pixel 10R in FIG. 3 ) is divided. An n-type semiconductor region 54 is provided in the dividing portion 41. The n-type semiconductor region 54 is used as the other main electrode of the transfer transistor TRR. A signal wiring 71 provided directly above the n-type semiconductor region 54 is electrically connected to the n-type semiconductor region 54.

[0065] Furthermore, the dividing point 41 is shared by the pixel isolation region 4 surrounding the pixel 10,1 and the pixel isolation region 4 surrounding the pixel 10,2 adjacent thereto in the direction of the arrow Y. In other words, the other main electrode (n-type semiconductor region 54) of the transfer transistor TRR is shared by the pixel 10R of the pixel 10,1 and the pixel 10R of the pixel 10,2.

[0066] Furthermore, in the pixel isolation region 4 surrounding the side surface of the pixel 10R, a dividing portion 42 is provided, where another portion of the pixel isolation region 4 in the extension direction (the lower right portion of the pixel 10R in FIG. 3 ) is divided. A p-type well contact region 6 is provided in the dividing portion 42. The p-type well contact region 6 is electrically connected to the p-type well region 302. The p-type well contact region 6 is electrically connected to a power supply wiring 72 provided directly above it.

[0067] Here, the p-type well region 302 disposed in the pixel 10L corresponds to the "first well region" according to the present technology, and the p-type well contact region 6 electrically connected to this p-type well region 302 corresponds to the "first well contact region" according to the present technology. Also, the p-type well region 302 disposed in the pixel 10R corresponds to the "second well region" according to the present technology, and the p-type well contact region 6 electrically connected to this p-type well region 302 corresponds to the "second well contact region" according to the present technology.

[0068] Furthermore, in the pixel isolation region 4 disposed between the pixel 10L and the pixel 10R, a separation portion 43 is disposed in which another portion of the extension direction of the pixel isolation region 4 (in FIG. 3 , the intermediate portion between the pixel 10L and the pixel 10R in the direction indicated by the arrow Y) is separated. An overflow path region 55 is embedded in the separation portion 43 in the depth direction of the semiconductor substrate 30. The overflow path region 55 is formed of a p-type semiconductor region or an n-type semiconductor region having an impurity density lower than the impurity density of the p-type well region 302 covering the pixel isolation region 4. The overflow path region 55 may also be formed of an i-type semiconductor region. The overflow path region 55 allows excess charge to flow from one of the photoelectric conversion element PDL of the pixel 10L and the photoelectric conversion element PDR of the pixel 10R to the other.

[0069] 3 , in the pixel 10L, a dividing portion 41 and a dividing portion 42 are arranged diagonally in a plan view. An n-type semiconductor region 54 that will become the other main electrode of the transfer transistor TRL is arranged in the dividing portion 41 on the diagonal. A p-type well contact region 6 is arranged in the dividing portion 42 on the diagonal. Similarly, in the pixel 10R, a dividing portion 41 and a dividing portion 42 are arranged diagonally in a plan view. An n-type semiconductor region 54 that will become the other main electrode of the transfer transistor TRR is arranged in the dividing portion 41 on the diagonal. A p-type well contact region 6 is arranged in the dividing portion 42 on the diagonal.

[0070] Furthermore, the pixel isolation region 4 is configured to include a plurality of separation portions 41, 42, and 43. In other words, in the first embodiment, the pixel isolation region 4 has at least two types of planar shapes in a planar view. That is, one is a pixel isolation region (first pixel isolation region) 4 that is formed in an L-shape in a planar view, including a portion extending in the direction of the arrow X and a portion extending in the direction of the arrow Y. The other is a pixel isolation region (second pixel isolation region) 4 that is formed in an I-shape that extends in the direction of the arrow Y. Each of the pixels 10L and 10R is surrounded by a combination of pixel isolation regions 4 having two types of planar shapes.

[0071] In the first embodiment, an I-shaped pixel isolation region 4 is disposed between the dividing portion 41 of pixel 10L and the dividing portion 41 of pixel 10R. Furthermore, an L-shaped pixel isolation region 4 is disposed between the dividing portion 42 of pixel 10L and the dividing portion 42 of pixel 10R. The planar shape of this pixel isolation region 4 is formed integrally with the pixel isolation region 4 of another pixel 10 adjacent on the opposite side in the direction of arrow Y, and is formed into a cross shape when the periphery is included.

[0072] Furthermore, in the first embodiment, the lengths in the direction of the arrow X of the dividing point 41 of the pixel isolation region 4 surrounding the periphery of pixel 10L and the dividing point 41 of the pixel isolation region 4 surrounding the periphery of pixel 10R are the same. The lengths in the direction of the arrow X of the dividing point 42 of the pixel isolation region 4 surrounding the periphery of pixel 10L and the dividing point 42 of the pixel isolation region 4 surrounding the periphery of pixel 10R are the same. The length in the direction of the arrow X of the dividing point 42 is the same as the length in the direction of the arrow Y of the dividing point 43. In other words, the pixel isolation region 4, the dividing point 41, the dividing point 42, and the dividing point 43 are each formed to have an optically symmetrical shape.

[0073] In addition, at least one of the decoupling points 41 and 42 is disposed on the periphery of the optical lens 9, which will be described later, in a plan view. The periphery of the optical lens 9 has a low ability to focus light L, so crosstalk can be effectively suppressed or prevented.

[0074] Here, the pixel 10,1 of the unit pixels will be mainly described, but the other unit pixels 10,2, 10,3, and 10,4 are each formed in a shape that is line-symmetrical to the pixel 10,1.

[0075] (4-4) Configuration of Optical Filter 8 As shown in FIG. 4, an optical filter 8 is disposed on the first surface 30A of the semiconductor substrate 30. In the first embodiment, the optical filter 8 is configured to include a red filter, a green filter, and a blue filter, which are the three primary colors of light. The optical filter 8 may also include an infrared filter. Here, an optical filter 8 of a different color is disposed for each unit pixel.

[0076] (4-5) Configuration of Optical Lens 9 As shown in Figures 3 and 4, the optical lens 9 is disposed on the first surface 30A of the semiconductor substrate 30 with the optical filter 8 interposed therebetween. In the first embodiment, the optical lens 9 is disposed for each unit pixel, and is formed in a circular shape in a plan view, and is formed in a curved shape that protrudes in the direction of arrow Z when viewed in the direction of arrow Y. In other words, the optical lens 9 is formed in a shape that focuses light L on the photoelectric conversion element PD. The optical lens 9 is configured as a so-called on-chip lens.

[0077] [Operation and Effect] As shown in FIGS. 3 to 6 , the photodetector 1 according to the first embodiment includes a pixel (first pixel) 10L, a pixel isolation region 4, and a transfer transistor (first transfer transistor) TRL. In the pixel 10L, a photoelectric conversion element (first photoelectric conversion element) PDL that converts light L into electric charge is disposed on the first surface 30A side of a semiconductor substrate 30 (first base 1A). The pixel isolation region 4 extends along the periphery of the side surface of the pixel 10L and optically and electrically isolates the pixel 10L from the surrounding area. The transfer transistor TRL is disposed on the second surface 30B side of the semiconductor substrate 30 so as to overlap the pixel 10L, and one of the pair of main electrodes (first main electrode) is electrically connected to the photoelectric conversion element PDL. A separation portion 41 is disposed at least on the second surface 30B side of the semiconductor substrate 30, where a portion of the pixel isolation region 4 in the extension direction is separated. The other main electrode (second main electrode) of the pair of transfer transistors TRL is disposed at this dividing portion 41. Here, the other main electrode is an n-type semiconductor region 54. According to the photodetector 1 configured in this manner, the other main electrode of the transfer transistor TRL is disposed at the dividing portion 41 in the extension direction of the pixel isolation region 4, so that the other main electrode can be disposed so as to overlap with the other main electrode in the extension direction of the pixel isolation region 4. This makes it possible to reduce the ratio of the area occupied by the transfer transistor TRL disposed in the pixel 10L to the area occupied by the pixel 10L.

[0078] 3 and 4 , in the photodetector 1, a sufficient separation distance Lgd can be ensured between the gate electrode 52 of the transfer transistor TRL and the n-type semiconductor region 54, which is the other main electrode, in the pixel 10L. A signal wiring 71 that forms a floating diffusion FD is connected to the n-type semiconductor region 54. With the photodetector 1 configured in this manner, it is possible to effectively suppress or prevent the electric field strength that affects the n-type semiconductor region 54, which is the other main electrode, from the gate electrode 52 of the transfer transistor TRL. This makes it possible to reduce or prevent the occurrence of white spots in the photodetector 1.

[0079] As shown in FIGS. 3 to 6 , the photodetector 1 further includes a p-type well region (first well region) 302 and a p-type well contact region (first well contact region) 6. A transfer transistor TRL is disposed on the second surface 30B side of the p-type well region 302. The p-type well contact region 6 is disposed at a separation portion 42, at least on the second surface 30B side of the p-type well region 302, where another portion of the pixel isolation region 4 in the extension direction is separated. The p-type well contact region 6 has the same conductivity type as the p-type well region 302 and is electrically connected to the p-type well region 302. According to the photodetector 1 configured in this manner, the p-type well contact region 6 is disposed at the separation portion 41 in the extension direction of the pixel isolation region 4, so that the p-type well contact region 6 can be disposed so as to overlap with the pixel isolation region 4 in the extension direction. This makes it possible to reduce the ratio of the area occupied by the p-type well contact region 6 disposed in the pixel 10L to the area occupied by the pixel 10L. In addition, since the area occupied by the active region in the pixel 10L can be increased, the number of saturated electrons can be increased.

[0080] As shown in FIGS. 3 to 6 , the photodetector 1 according to the first embodiment includes a pixel (second pixel) 10R, a pixel isolation region 4, and a transfer transistor (second transfer transistor) TRR. In the pixel 10R, a photoelectric conversion element (second photoelectric conversion element) PDR that converts light L into electric charge is disposed on the first surface 30A side of a semiconductor substrate 30 (first base 1A). The pixel isolation region 4 extends along the periphery of the side surface of the pixel 10R, optically and electrically isolating the pixel 10R from the surroundings. The transfer transistor TRR is disposed on the second surface 30B side of the semiconductor substrate 30, overlapping the pixel 10R, and one of the pair of main electrodes (third main electrode) is electrically connected to the photoelectric conversion element PDR. A separation portion 41 is disposed at least on the second surface 30B side of the semiconductor substrate 30, where a portion of the pixel isolation region 4 in the extension direction is separated. The other main electrode (fourth main electrode) of the pair of transfer transistors TRR is disposed at the decoupling point 41. Here, the other main electrode is an n-type semiconductor region 54. According to the photodetector 1 configured in this manner, similar to the pixel 10L, it is possible to reduce the ratio of the area occupied by the transfer transistor TRR disposed in the pixel 10R to the area occupied by the pixel 10R.

[0081] 3 and 4 , in the photo-detecting device 1, a sufficient separation distance Lgd can be ensured between the gate electrode 52 of the transfer transistor TRR and the n-type semiconductor region 54, which is the other main electrode, in the pixel 10R. According to the photo-detecting device 1 configured in this manner, it is possible to effectively suppress or prevent the electric field strength that affects the n-type semiconductor region 54, which is the other main electrode, from the gate electrode 52 of the transfer transistor TRR. Therefore, it is possible to improve the occurrence of white spots in the photo-detecting device 1.

[0082] As shown in FIGS. 3 to 6 , the photodetector 1 further includes a p-type well region (second well region) 302 and a p-type well contact region (second well contact region) 6. A transfer transistor TRR is disposed on the second surface 30B side of the p-type well region 302. The p-type well contact region 6 is disposed at a separation portion 42, at least on the second surface 30B side of the p-type well region 302, where another portion of the pixel isolation region 4 in the extension direction is separated. The p-type well contact region 6 has the same conductivity type as the p-type well region 302 and is electrically connected to the p-type well region 302. According to the photodetector 1 configured in this manner, similar to the pixel 10L, the ratio of the area occupied by the p-type well contact region 6 disposed in the pixel 10R to the area occupied by the pixel 10R can be reduced. In addition, the area occupied by the active region in the pixel 10R can be increased, thereby increasing the number of saturated electrons.

[0083] Furthermore, as shown in FIGS. 3 and 5 , the photodetector 1 includes an overflow path region 55. The overflow path region 55 is disposed at a separation point 43 where another portion of the pixel isolation region 4 disposed between the pixel 10L and the pixel 10R is separated in the extension direction. The overflow path region 55 allows excess charge to flow from one of the photoelectric conversion element PDL of the pixel 10L and the photoelectric conversion element PDR of the pixel 10R to the other. Here, the ratio of the area occupied by the transfer transistor TRL in the pixel 10L is reduced, and in addition, the ratio of the area occupied by the transfer transistor TRR in the pixel 10R is reduced. In other words, the degree of freedom in the placement of the transfer transistors TRL and TRR can be improved. Therefore, the placement positions of the transfer transistors TRL and TRR can be closer to the overflow path region 55. According to the photodetector 1 configured in this manner, the influence of the diffusion region around the overflow path region 55 can be reduced, and a transfer potential can be easily generated.

[0084] 3 and 4 , in the photodetector 1, an optical lens 9 is disposed on the first surface 30A side of the semiconductor substrate 30, spanning the pixels 30L and 30R. In plan view, one or more selected from the other main electrodes (n-type semiconductor regions 54) of the transfer transistors TRL and TRR and the p-type well contact region 6 are disposed on the periphery of the optical lens 9. According to the photodetector 1 configured in this manner, the peripheral portion of the optical lens 9 has a low ability to collect light L, and therefore crosstalk can be effectively suppressed or prevented.

[0085] 3 , in the photodetector 1, the pixel 10R is formed to have a shape that is optically symmetrical with respect to the pixel 10L in a plan view. Here, not only the shapes of the pixel 10L and the pixel 10R, but also the shapes of the transfer transistors TRL and TRR, the shape of the pixel isolation region 4, and the like are formed to have a shape that is optically symmetrical. Therefore, anisotropic color mixing (crosstalk) caused by reflection of incident light can be effectively suppressed or prevented.

[0086] 2. Second Embodiment A photodetector 1 according to a second embodiment of the present disclosure will be described using Figure 7. The second embodiment describes an example in which the circuit configurations of the pixels 10 and pixel circuits 20 in the photodetector 1 according to the first embodiment are changed. Note that in the second embodiment and the subsequent embodiments, components that are the same as or substantially the same as components of the photodetector 1 according to the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

[0087] [Circuit Configuration of Pixels 10 and Pixel Circuits 20 of Photodetection Device 1] Fig. 7 shows an example of the circuit configuration of the pixels 10 and pixel circuits 20 of the photodetection device 1. As shown in Fig. 7, in the photodetection device 1 according to the second embodiment, one pixel 10 is electrically connected to one pixel circuit 20. One pixel 10 connected to one pixel circuit 20 constitutes a unit pixel. In other words, the unit pixel is configured in a "1 x 1" pixel array.

[0088] The pixel 10 is configured as a phase difference detection pixel, similar to the pixel 10 of the photodetector 1 according to the first embodiment. That is, the pixel 10 includes a pixel 10L and a pixel 10R.

[0089] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0090] [Operational Effects] According to the photodetector 1 of the second embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the first embodiment.

[0091] 3. Third Embodiment A photodetector 1 according to a third embodiment of the present disclosure will be described with reference to Fig. 8. The third embodiment describes an example in which the circuit configurations of the pixels 10 and the pixel circuits 20 in the photodetector 1 according to the first embodiment are changed.

[0092] [Circuit Configuration of Pixels 10 and Pixel Circuits 20 of Photodetection Device 1] Fig. 8 shows an example of the circuit configuration of the pixels 10 and pixel circuits 20 of the photodetection device 1. As shown in Fig. 8, in the photodetection device 1 according to the third embodiment, two pixels 10,1 and 10,2 are electrically connected to one pixel circuit 20, and the two pixels 10 share one pixel circuit 20. The two pixels 10 sharing this one pixel circuit 20 constitute a unit pixel. In other words, the unit pixel is configured in a "2 x 1" pixel array.

[0093] Each of the pixel 10,1 and the pixel 10,2 is configured as a phase difference detection pixel, similar to the pixel 10 of the photodetector 1 according to the first embodiment. That is, the pixel 10 includes a pixel 10L and a pixel 10R.

[0094] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0095] [Operational Effects] According to the photodetector 1 of the third embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the first embodiment.

[0096] 4. Fourth Embodiment A photodetector 1 according to a fourth embodiment of the present disclosure will be described with reference to Fig. 9. The fourth embodiment describes an example in which the circuit configurations of the pixels 10 and the pixel circuits 20 in the photodetector 1 according to the first embodiment are changed.

[0097] [Circuit Configuration of Pixels 10 and Pixel Circuits 20 of Photodetection Device 1] Fig. 9 shows an example of the circuit configuration of the pixels 10 and pixel circuits 20 of the photodetection device 1. As shown in Fig. 9, in the photodetection device 1 according to the fourth embodiment, similar to the photodetection device 1 according to the first embodiment, four pixels 10,1 to 10,4 are electrically connected to one pixel circuit 20, and the four pixels 10 share one pixel circuit 20. The four pixels 10 sharing this one pixel circuit 20 constitute a unit pixel. In other words, the unit pixel is configured in a "2 x 2" pixel array.

[0098] In the fourth embodiment, the pixels 10 are configured as normal pixels, and are not configured as phase difference detection pixels, unlike the pixels 10 of the photodetection device 1 according to the first embodiment.

[0099] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0100] [Operational Effects] According to the photodetector 1 of the fourth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the first embodiment.

[0101] 5. Fifth Embodiment A photodetector 1 according to a fifth embodiment of the present disclosure will be described with reference to Fig. 10. The fifth embodiment describes an example in which the planar structure of the pixel 10 and the vertical cross-sectional configuration of the pixel are changed in the photodetector 1 according to the first embodiment.

[0102] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 10 shows an example of a specific planar configuration of the pixel 10 of the photodetector 1. As shown in Fig. 10, in the photodetector 1 according to the fifth embodiment, one pixel 10L constituting the phase difference detection pixel of the pixel 10 includes a transfer transistor TRL configured by a plurality of transfer transistors TRL1 and TRL2. The transfer transistors TRL1 and TRL2 are electrically connected in parallel. In the fifth embodiment, the transfer transistor TRL includes two transfer transistors TRL1 and TRL2, and is therefore configured as a twin-gate structure.

[0103] Similarly, the other pixel 10R constituting the phase difference detection pixel includes a transfer transistor TRR configured by a plurality of transfer transistors TRR1 and TRR2. The transfer transistors TRR1 and TRR2 are electrically connected in parallel. The transfer transistor TRR is configured as a twin-gate structure, similar to the transfer transistor TRL.

[0104] Furthermore, the transfer transistor TRL1 and the transfer transistor TRL2 disposed in the pixel 10L of the pixel 10,1 and the transfer transistor TRL1 and the transfer transistor TRL2 disposed in the pixel 10L of the pixel 10,2 are disposed around the dividing point 41. In other words, a total of four transfer transistors TRL1 and TRL2 are disposed around one n-type semiconductor region 54 or signal wiring 71, which serves as the other main electrode.

[0105] Similarly, the transfer transistor TRR1 and the transfer transistor TRR2 disposed in the pixel 10R of the pixel 10,1, and the transfer transistor TRR1 and the transfer transistor TRR2 disposed in the pixel 10R of the pixel 10,2 are disposed around the dividing point 41. In other words, a total of four transfer transistors TRR1 and TRR2 are disposed around one n-type semiconductor region 54 or signal wiring 71 that serves as the other main electrode.

[0106] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0107] [Effects] The photodetector 1 according to the fifth embodiment can achieve the same effects as those achieved by the photodetector 1 according to the first embodiment. Furthermore, in the photodetector 1, the transfer transistor TR has a multi-gate structure. The photodetector 1 configured in this manner can increase the number of saturated electrons, thereby enabling light to be detected with an expanded dynamic range.

[0108] The photodetector 1 according to the fifth embodiment can be combined with the photodetector 1 according to all of the first to fourth embodiments and the sixth and subsequent embodiments.

[0109] 11 and 12 , a photodetector 1 according to a sixth embodiment of the present disclosure will be described. In the sixth embodiment, an example will be described in which the planar structure and the longitudinal cross-sectional configuration of the pixel 10 in the photodetector 1 according to the first embodiment are changed.

[0110] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 11 shows an example of a specific planar configuration of the pixel 10 of the photodetector 1. Fig. 12 shows an example of a specific longitudinal cross-sectional configuration of the pixel 10. As shown in Figs. 11 and 12 , in the photodetector 1 according to the sixth embodiment, one pixel 10L constituting a phase difference detection pixel of the pixel 10 has a dividing portion 42 disposed in the lower right portion in plan view. A p-type well contact region 6 is disposed in the dividing portion 42, and the p-type well contact region 6 is electrically connected to the p-type well region 302.

[0111] In plan view, similar to dividing point 41, dividing point 42 is disposed between L-shaped pixel isolation region 4 and I-shaped pixel isolation region 4. Here, the length of dividing point 42 in the direction of arrow X is the same as the length of dividing point 41 in the direction of arrow X.

[0112] Similarly, the other pixel 10R constituting the phase difference detection pixel of the pixel 10 has a division point 42 arranged in the lower left portion in plan view. A p-type well contact region 6 is arranged in the division point 42, and the p-type well contact region 6 is electrically connected to the p-type well region 302. In plan view, the division point 42 is arranged between the L-shaped pixel isolation region 4 and the I-shaped pixel isolation region 4, and the length of the division point 42 in the direction of arrow X is the same as the length of the division point 41 in the same direction.

[0113] The dividing point 42, like the dividing point 41, is disposed on the periphery of the optical lens 9. In other words, the dividing point 41 and the dividing point 42 are each disposed at a position that can improve optical symmetry around the center position of the optical lens 9.

[0114] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0115] [Operational Effects] According to the photodetector 1 of the sixth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the first embodiment.

[0116] 11 and 12, in the photodetector 1, the dividing points 41 and 42 are each disposed at a position that can improve optical symmetry around the center position of the optical lens 9. According to the photodetector 1 configured in this manner, it is possible to effectively suppress or prevent anisotropic color mixing that accompanies reflection of incident light.

[0117] 13 and 14, a photodetector 1 according to a seventh embodiment of the present disclosure will be described. The seventh embodiment describes an example in which the planar structure and the longitudinal cross-sectional configuration of the pixel 10 in the photodetector 1 according to the sixth embodiment are changed.

[0118] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 13 shows an example of a specific planar configuration of the pixel 10 of the photodetector 1. Fig. 14 shows an example of a specific longitudinal cross-sectional configuration of the pixel 10. As shown in Figs. 13 and 14 , in the photodetector 1 according to the seventh embodiment, one pixel 10L constituting a phase difference detection pixel of the pixel 10 has a dividing portion 42 disposed in the lower left portion in plan view. A p-type well contact region 6 is disposed in the dividing portion 42, and the p-type well contact region 6 is electrically connected to the p-type well region 302.

[0119] In a plan view, the dividing point 42 is disposed between the L-shaped pixel isolation regions 4. Here, the length of the dividing point 42 in the direction of arrow X is the same as the length of the dividing point 41 in the direction of arrow X. Furthermore, the dividing point 42 is separated from the dividing point 42 of pixel 10R of the pixel 10 adjacent on the opposite side of the direction of arrow X by the pixel isolation region 4 therebetween.

[0120] Similarly, the other pixel 10R constituting the phase difference detection pixel of the pixel 10 has a dividing portion 42 disposed in its lower right portion in plan view. A p-type well contact region 6 is disposed in the dividing portion 42, and the p-type well contact region 6 is electrically connected to the p-type well region 302. In plan view, the dividing portion 42 is disposed between the L-shaped pixel isolation regions 4, and the length of the dividing portion 42 in the direction of arrow X is the same as the length of the dividing portion 41 in the same direction. Furthermore, the dividing portion 42 is separated from the dividing portion 42 of the pixel 10L of the pixel 10 adjacent in the direction of arrow X by the pixel isolation region 4 therebetween.

[0121] The dividing point 42, like the dividing point 41, is disposed on the periphery of the optical lens 9. In other words, the dividing point 41 and the dividing point 42 are each disposed at a position that can improve optical symmetry around the center position of the optical lens 9.

[0122] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0123] [Operational Effects] According to the photodetector 1 of the seventh embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the sixth embodiment.

[0124] 15 and 16 , a photodetector 1 according to an eighth embodiment of the present disclosure will be described. The eighth embodiment describes an example in which the planar structure and the longitudinal cross-sectional configuration of the pixel 10 in the photodetector 1 according to the first embodiment are changed.

[0125] [Device Configuration of Pixel 10 of Photodetector 1] FIG. 15 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. FIG. 16 shows an example of a specific longitudinal cross-sectional configuration of the pixel 10. As shown in FIGS. 15 and 16 , in the photodetector 1 according to the eighth embodiment, one pixel 10L constituting a phase difference detection pixel of the pixel 10 has a p-type well contact region 6 disposed in the lower left corner in plan view. In the eighth embodiment, no dividing portion 42 is provided. That is, the p-type well contact region 6 is disposed on the second surface 30B side of the p-type well region 302 within a region partially surrounded by the pixel isolation region 4.

[0126] Although the shape is not particularly limited, here, the p-type well contact region 6 is formed in a triangular shape in a plan view.

[0127] Similarly, the other pixel 10R constituting the phase difference detection pixel of the pixel 10 has a p-type well contact region 6 disposed in the lower right corner in plan view. The p-type well contact region 6 is disposed on the second surface 30B side of the p-type well region 302 in a region partially surrounded by the pixel isolation region 4. Here, the p-type well contact region 6 is formed in a triangular shape in plan view.

[0128] The p-type well contact region 6 is disposed on the periphery of the optical lens 9. In other words, the p-type well contact region 6 is disposed at a position that can improve optical symmetry around the center position of the optical lens 9.

[0129] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0130] [Operational Effects] According to the photodetector 1 of the eighth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the first embodiment.

[0131] 9. Ninth embodiment A photodetector 1 according to a ninth embodiment of the present disclosure will be described with reference to Fig. 17. In the ninth embodiment, an example will be described in which the photodetector 1 according to the fifth embodiment and the photodetector 1 according to the eighth embodiment are combined.

[0132] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 17 shows an example of a specific planar configuration of the pixel 10 of the photodetector 1. As shown in Fig. 17 , in the photodetector 1 according to the ninth embodiment, similar to the photodetector 1 according to the fifth embodiment, the pixel 10L of the pixel 10 includes a transfer transistor TRL configured by a plurality of transfer transistors TRL1 and TRL2. Furthermore, the pixel 10R of the pixel 10 includes a transfer transistor TRR configured by a plurality of transfer transistors TRR1 and TRR2.

[0133] Furthermore, in the photodetector 1, similarly to the photodetector 1 according to the eighth embodiment, the pixel 10L has the p-type well contact region 6 disposed in the lower left corner in plan view. The pixel 10R has the p-type well contact region 6 disposed in the lower right corner in plan view. No dividing portion 42 is provided.

[0134] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the fifth embodiment and the photodetector 1 according to the eighth embodiment.

[0135] [Effects] According to the photodetector 1 of the ninth embodiment, it is possible to obtain an effect that combines the effects obtained by the photodetector 1 of the fifth embodiment and the effects obtained by the photodetector 1 of the eighth embodiment.

[0136] 10. Tenth embodiment A photodetector 1 according to a tenth embodiment of the present disclosure will be described with reference to Figures 18 and 19. The tenth embodiment describes an example in which the planar structure and longitudinal cross-sectional configuration of the pixel 10 in the photodetector 1 according to the first embodiment are changed.

[0137] [Device Configuration of Pixel 10 of Photodetection Device 1] Fig. 18 shows an example of a specific planar configuration of the pixel 10 of the photodetection device 1. Fig. 19 shows an example of a specific longitudinal cross-sectional configuration of the pixel 10. As shown in Fig. 18 and Fig. 19 , in the photodetection device 1 according to the eighth embodiment, in one pixel 10L and the other pixel 10R that constitute the phase difference detection pixel of the pixel 10, the dividing portions 41 that are arranged in the pixel isolation region 4 that surrounds the periphery are integrally formed.

[0138] More specifically, the pixel isolation region 4 between the dividing portion 41 disposed in the pixel isolation region 4 surrounding the periphery of pixel 10L and the dividing portion 41 disposed in the pixel isolation region 4 surrounding the periphery of pixel 10R is removed. The two dividing portions 41 are formed as one dividing portion 41.

[0139] One n-type semiconductor region 54 is disposed in this one dividing portion 41. The n-type semiconductor region 54 is used as the other main electrode of the transfer transistor TRL of the pixel 10L of the pixel 10,1 and the other main electrode of the transfer transistor TRR of the pixel 10R. Furthermore, the n-type semiconductor region 54 is used as the other main electrode of the transfer transistor TRL of the pixel 10L of the pixel 10,2 adjacent in the direction of the arrow Y and the other main electrode of the transfer transistor TRR of the pixel 10R. In other words, one n-type semiconductor region 54 disposed in one dividing portion 41 is used as the other main electrode of the four transfer transistors TR.

[0140] The dividing portion 42 and the p-type well contact region 6 have the same configuration as the dividing portion 42 and the p-type well contact region 6 of the photodetector 1 according to the first embodiment.

[0141] Moreover, in the tenth embodiment, the overflow path region 55 is disposed at the dividing portion 41. To explain in more detail, in a plan view, in the pixel 10,1, the overflow path region 55 is disposed between the end in the extension direction of the pixel isolation region 4 disposed between the pixel 10L and the pixel 10R and the n-type semiconductor region 54. In other words, the dividing portion 43 (see FIG. 3, for example) required for disposing the overflow path region 55 is incorporated into (formed integrally with) the dividing portion 41 and is not effectively disposed.

[0142] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0143] [Operational Effects] According to the photodetector 1 of the tenth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the first embodiment.

[0144] Furthermore, in the photodetector 1, as shown in Figures 18 and 19, the number of dividing points 41 in the pixel isolation region 4 is reduced, and further, dividing points 43 are not provided, so that anisotropic color mixing caused by reflection of incident light at the end of the pixel isolation region 4 can be effectively suppressed or prevented.

[0145] 20 and 21, a photodetector 1 according to an eleventh embodiment of the present disclosure will be described. In the eleventh embodiment, an example in which the photodetector 1 according to the eighth embodiment and the photodetector 1 according to the tenth embodiment are combined will be described.

[0146] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 20 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. Fig. 21 shows an example of a specific longitudinal cross-sectional configuration of a pixel 10. As shown in Figs. 20 and 21 , in the photodetector 1 according to the eleventh embodiment, similar to the photodetector 1 according to the tenth embodiment, one dividing portion 41 is provided in each of the pixels 10L and 10R of the pixel 10. One n-type semiconductor region 54 is provided in each dividing portion 41. The n-type semiconductor region 54 is used as the other main electrode of the transfer transistor TR of each of the pixels 10L and 10R.

[0147] Furthermore, in the photodetector 1 according to the eleventh embodiment, similarly to the photodetector 1 according to the eighth embodiment, in plan view, a p-type well contact region 6 is arranged in the lower left corner of pixel 10L, and a p-type well contact region 6 is arranged in the lower right corner of pixel 10R.

[0148] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the eighth embodiment and the photodetector 1 according to the tenth embodiment.

[0149] [Effects] According to the photodetector 1 of the 11th embodiment, it is possible to obtain an effect that combines the effects obtained by the photodetector 1 of the 8th embodiment and the effects obtained by the photodetector 1 of the 10th embodiment.

[0150] 22 and 23, a photodetector 1 according to a twelfth embodiment of the present disclosure will be described. The twelfth embodiment describes an example in which the planar structure of pixels and the longitudinal cross-sectional configuration of pixels are changed in the photodetector according to the tenth embodiment.

[0151] [Device Configuration of Pixel 10 of Photodetection Device 1] Fig. 22 shows an example of a specific planar configuration of the pixel 10 of the photodetection device 1. Fig. 23 shows an example of a specific longitudinal cross-sectional configuration of the pixel 10. As shown in Figs. 22 and 23 , in the photodetection device 1 according to the twelfth embodiment, a dividing portion 43 is arranged in the middle of the extension direction (direction of arrow Y) in the pixel isolation region 4 between one pixel 10L and the other pixel 10R that constitute the phase difference detection pixel of the pixel 10. An overflow path region 55 is arranged in this dividing portion 43.

[0152] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the tenth embodiment.

[0153] [Operational Effects] According to the photodetector 1 of the twelfth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the tenth embodiment.

[0154] 22 , in the photodetector 1, a dividing portion 43 is disposed in the middle of the extension direction of the pixel isolation region 4, and an overflow path region 55 is disposed in this dividing portion 43. According to the photodetector 1 configured in this manner, the overflow path region 55 is disposed in the middle of each of the pixels 10L and 10R of the pixel 10 in the direction of the arrow Y, and therefore the transfer potential can be generated stably.

[0155] 24 and 25, a photodetector 1 according to a thirteenth embodiment of the present disclosure will be described. In the thirteenth embodiment, an example will be described in which the photodetector 1 according to the eleventh embodiment and the photodetector 1 according to the twelfth embodiment are combined.

[0156] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 24 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. Fig. 25 shows an example of a specific longitudinal cross-sectional configuration of a pixel 10. As shown in Figs. 24 and 25 , in the photodetector 1 according to the thirteenth embodiment, one dividing portion 41 is provided in each of the pixels 10L and 10R of the pixel 10, similar to the photodetector 1 according to the eleventh embodiment. One n-type semiconductor region 54 is provided in each dividing portion 41. The n-type semiconductor region 54 is used as the other main electrode of the transfer transistor TR of each of the pixels 10L and 10R.

[0157] In the photodetector 1, a p-type well contact region 6 is disposed in the lower left corner of the pixel 10L in plan view, and a p-type well contact region 6 is disposed in the lower right corner of the pixel 10R.

[0158] In the photodetector 1 according to the thirteenth embodiment, similarly to the photodetector 1 according to the twelfth embodiment, a dividing portion 43 is disposed in the middle in the extension direction of the pixel isolation region 4 between the pixel 10L and the pixel 10R of the pixel 10. An overflow path region 55 is disposed in this dividing portion 43.

[0159] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the eleventh embodiment and the photodetector 1 according to the twelfth embodiment.

[0160] [Effects] According to the photodetector 1 of the thirteenth embodiment, it is possible to obtain an effect that combines the effects obtained by the photodetector 1 of the eleventh embodiment and the effects obtained by the photodetector 1 of the twelfth embodiment.

[0161] 26, a photodetector 1 according to a fourteenth embodiment of the present disclosure will be described. The fourteenth embodiment describes an example in which the planar structure and the longitudinal cross-sectional configuration of the pixel 10 in the photodetector 1 according to the tenth embodiment are changed.

[0162] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 26 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. As shown in Fig. 26, in the photodetector 1 according to the fourteenth embodiment, similar to the photodetector 1 according to the tenth embodiment, one dividing portion 41 is provided in each of the pixels 10L and 10R of the pixel 10. One n-type semiconductor region 54 is provided in one dividing portion 41. The n-type semiconductor region 54 is used as the other main electrode of the transfer transistor TR of each of the pixels 10L and 10R.

[0163] Meanwhile, one dividing portion 42 is disposed at the end portion of the pixel isolation region 4 between pixel 10L and pixel 10R of pixel 10 in the extension direction opposite to the direction of arrow Y. This one dividing portion 42, like dividing portion 41, is formed by integrating the dividing portion 42 of pixel 10L and the dividing portion 42 of pixel 10R. One p-type well contact region 6 is disposed at one dividing portion 42. This p-type well contact region 6 is electrically connected to and shared by the p-type well region 302 of pixel 10L and the p-type well region 302 of pixel 10R.

[0164] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the tenth embodiment.

[0165] [Operational Effects] According to the photodetector 1 of the fourteenth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the tenth embodiment.

[0166] 26 , in the photodetector 1, the dividing points 41 and the dividing points 42 are shared between the pixel 10L and the pixel 10R. Therefore, in the photodetector 1, the number of dividing points 41 and the number of dividing points 42 in the pixel isolation region 4 can be reduced, and therefore anisotropic color mixing caused by reflection of incident light at the end of the pixel isolation region 4 can be effectively suppressed or prevented.

[0167] 15. Fifteenth embodiment A photodetector 1 according to a fifteenth embodiment of the present disclosure will be described with reference to Fig. 27. The fifteenth embodiment describes an example in which the planar structure of the pixel 10 and the longitudinal cross-sectional configuration of the pixel 10 are changed in the photodetector 1 according to the fourteenth embodiment.

[0168] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 27 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. As shown in Fig. 27 , in the photodetector 1 according to the fifteenth embodiment, one dividing portion 41 is provided in each of the pixels 10L and 10R of the pixel 10, similar to the photodetector 1 according to the fourteenth embodiment. One n-type semiconductor region 54 is provided in one dividing portion 41. The n-type semiconductor region 54 is used as the other main electrode of the transfer transistor TR of each of the pixels 10L and 10R.

[0169] Furthermore, one dividing portion 42 is disposed in each of the pixels 10L and 10R. One p-type well contact region 6 is disposed in each dividing portion 42. The p-type well contact region is electrically connected to the p-type well region 302 of each of the pixels 10L and 10R.

[0170] Furthermore, in the photodetector 1 according to the fifteenth embodiment, a dividing point 45 is arranged in the pixel isolation region 4 between pixel 10L of pixel 10,1 and pixel 10R of pixel 10,3 adjacent to the pixel 10,1 on the opposite side of the arrow X direction. The dividing point 45 is arranged in a middle part of the pixel isolation region 4 in the extension direction of the arrow Y. Similarly, a dividing point 45 is arranged in the pixel isolation region 4 between pixel 10R of pixel 10,1 and pixel 10L of pixel 10,3 adjacent to the pixel 10,1 in the arrow X direction. The dividing point 45 is arranged in a middle part of the pixel isolation region 4 in the extension direction.

[0171] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the fourteenth embodiment.

[0172] [Operational Effects] According to the photodetector 1 of the fifteenth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the fourteenth embodiment.

[0173] 27 , in the photodetector 1, dividing points 45 are disposed in the middle of the extension direction of the pixel isolation region 4 between pixels 10 adjacent to each other in the direction of the arrow X. In other words, the number of dividing points 45 of the pixel isolation region 4 in the direction of the arrow X is equal to the number of dividing points 41 and dividing points 42 of the pixel isolation region 4 in the direction of the arrow Y, and therefore anisotropic color mixing can be effectively suppressed or prevented.

[0174] 28, a photodetector 1 according to a sixteenth embodiment of the present disclosure will be described. The sixteenth embodiment describes an example in which the planar structure of the pixel 10 and the longitudinal cross-sectional configuration of the pixel 10 are changed in the photodetector 1 according to the fifteenth embodiment.

[0175] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 28 shows an example of a specific planar configuration of a pixel 10 of a photodetector 1. As shown in Fig. 28 , in a photodetector 1 according to the sixteenth embodiment, a pixel isolation region 4 extending in the direction of arrow Y is disposed between pixel 10L and pixel 10R of the pixel 10 in the photodetector 1 according to the fifteenth embodiment. A portion 46 of the pixel isolation region 4 extends in the direction of arrow X and the opposite direction to the direction of arrow X from a middle portion of the pixel isolation region 4 in the extension direction in each of pixels 10L and 10R. The pixel isolation region 4 and portion 46 are formed in a cross shape in a plan view.

[0176] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the fifteenth embodiment.

[0177] [Operational Effects] According to the photodetector 1 of the sixteenth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the fourteenth embodiment.

[0178] 28 , in the photodetector 1, a part 46 of the pixel isolation region 4 extends between the pixel 10L and the pixel 10R in the middle of the pixel isolation region 4 in the extension direction. The end of this part 46 in the extension direction can be regarded as a dividing point. Therefore, in addition to the dividing point 45 of the pixel isolation region 4 in the direction of the arrow X, it is possible to further increase the number of dividing points in the same direction, thereby effectively suppressing or preventing anisotropic color mixing.

[0179] 17. Seventeenth embodiment A photodetector 1 according to a seventeenth embodiment of the present disclosure will be described with reference to Fig. 29. The seventeenth embodiment describes an example in which the planar structure of the pixel 10 and the longitudinal cross-sectional configuration of the pixel 10 are changed in the photodetector 1 according to the sixteenth embodiment.

[0180] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 29 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. As shown in Fig. 29 , in the photodetector 1 according to the seventeenth embodiment, a pixel isolation region 4 and a portion 46 thereof are disposed between pixel 10L and pixel 10R of the pixel 10 in the photodetector 1 according to the sixteenth embodiment. The pixel isolation region 4 and the portion 46 are formed in a cross shape in plan view.

[0181] The photodetector 1 according to the seventeenth embodiment does not have the dividing portion 45 of the photodetector 1 according to the fifteenth embodiment.

[0182] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the sixteenth embodiment.

[0183] [Operational Effects] According to the photodetector 1 of the seventeenth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the sixteenth embodiment.

[0184] 30 and 31 , a photodetector 1 according to an eighteenth embodiment of the present disclosure will be described. The eighteenth embodiment describes an example in which the planar structure and the longitudinal cross-sectional configuration of the pixel 10 in the photodetector 1 according to the fourteenth embodiment are changed.

[0185] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 30 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. Fig. 31 shows an example of a specific longitudinal cross-sectional configuration of a pixel 10. As shown in Figs. 30 and 31 , in the photodetector 1 according to the eighteenth embodiment, similar to the photodetector 1 according to the fourteenth embodiment, one dividing portion 41 is provided in each of the pixels 10L and 10R of the pixel 10. One n-type semiconductor region 54 is provided in each dividing portion 41. The n-type semiconductor region 54 is used as the other main electrode of the transfer transistor TR of each of the pixels 10L and 10R.

[0186] The dividing portion 41 is also shared by the pixel 10,2, which is adjacent to the pixel 10,1 in the direction of the arrow Y. In other words, the n-type semiconductor region 54 disposed at the dividing portion 41 is used as the other main electrode of the transfer transistor TR of each of the pixel 10,1 and the pixel 10,2.

[0187] On the other hand, one dividing portion 42 is disposed in pixel 10L and pixel 10R of pixel 10. One p-type well contact region 6 is disposed in one dividing portion 42. The p-type well contact region 6 is electrically connected to the p-type well regions 302 of pixel 10L and pixel 10R. In other words, the p-type well contact region 6 of pixel 10L and pixel 10R is shared.

[0188] Here, the dividing point 42 is not shared by the pixel 10,2, which is adjacent to the pixel 10,1 on the opposite side in the direction of the arrow Y. In other words, a pixel isolation region 4 extending in the direction of the arrow X is disposed between the dividing point 42 disposed in the pixel 10,1 and the dividing point 42 disposed in the pixel 10,2.

[0189] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the fourteenth embodiment.

[0190] [Operational Effects] According to the photodetector 1 of the eighteenth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the fourteenth embodiment.

[0191] 19. Nineteenth embodiment A photodetector 1 according to a nineteenth embodiment of the present disclosure will be described with reference to Fig. 32. The nineteenth embodiment describes an example in which the planar structure of the pixel 10 and the longitudinal cross-sectional configuration of the pixel 10 are changed in the photodetector 1 according to the eighteenth embodiment.

[0192] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 32 shows an example of a specific planar configuration of the pixel 10 of the photodetector 1. As shown in Fig. 32, in the photodetector 1 according to the nineteenth embodiment, one dividing portion 41 is provided in each of the pixels 10L and 10R of the pixel 10. One n-type semiconductor region 54 is provided in one dividing portion 41. The n-type semiconductor region 54 is used as the other main electrode of the transfer transistor TR of each of the pixels 10L and 10R.

[0193] Furthermore, the dividing portion 41 is shared by the pixel 10,2, which is adjacent to the pixel 10,1 in the direction of the arrow Y. In other words, a pixel isolation region 4 extending in the direction of the arrow X is disposed between the dividing portion 41 disposed in the pixel 10,1 and the dividing portion 41 disposed in the pixel 10,2.

[0194] Meanwhile, similarly to the photodetector 1 according to the eighteenth embodiment, one dividing portion 42 is disposed in each of the pixels 10L and 10R of the pixel 10. One p-type well contact region 6 is disposed in one dividing portion 42. The p-type well contact region 6 is electrically connected to the p-type well regions 302 of the pixel 10L and the pixel 10R.

[0195] The dividing portion 42 is not shared by the pixel 10,2 adjacent to the pixel 10,1 on the opposite side in the direction of the arrow Y. In other words, a pixel isolation region 4 extending in the direction of the arrow X is disposed between the dividing portion 42 disposed in the pixel 10,1 and the dividing portion 42 disposed in the pixel 10,2.

[0196] In addition, the pixel isolation region 4 and a part 46 formed in a cross shape in a plan view are disposed between the pixel 10L and the pixel 10R of the pixel 10.

[0197] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the eighteenth embodiment.

[0198] [Operational Effects] According to the photodetector 1 of the nineteenth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the eighteenth embodiment.

[0199] 20. Twentieth Embodiment A photodetector 1 according to a twentieth embodiment of the present disclosure will be described with reference to Figures 33 and 34. The twentieth embodiment describes an example in which the planar structure of the pixel 10 and the longitudinal cross-sectional configuration of the pixel 10 are changed in the photodetector 1 according to the tenth embodiment.

[0200] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 33 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. Fig. 34 shows an example of a specific longitudinal cross-sectional configuration of a pixel 10. As shown in Figs. 33 and 34 , the photodetector 1 according to the twentieth embodiment further includes a dark current prevention region 305 and a charge accumulation region 306 in the photodetector 1 according to the tenth embodiment.

[0201] The dark current prevention region 305 is disposed on the second surface 30B side of the p-type well region 302, in a region separate from the region of the transfer transistor TR of the pixel 10. The dark current prevention region 305 is formed of a p-type semiconductor region having an impurity density higher than the impurity density of the p-type well region 302.

[0202] The charge accumulation region 306 is disposed in the thickness direction of the semiconductor substrate 30 between the n-type semiconductor region 301 of the photoelectric conversion element PD of the pixel 10 and the dark current prevention region 305. The charge accumulation region 306 is formed of an n-type semiconductor region having a higher impurity density than the impurity density of the n-type semiconductor region 301.

[0203] In the twentieth embodiment, a pixel isolation region 4 extending in the direction of arrow Y is disposed between pixel 10L of pixel 10,1 and pixel 10R of pixel 10,3 adjacent to the pixel 10,1 on the opposite side of the direction of arrow X. A portion 47 of the pixel isolation region 4 extends in the direction of arrow X from a middle portion of the extension direction of the pixel isolation region 4 to pixel 10L of pixel 10,1. Furthermore, a pixel isolation region 4 extending in the direction of arrow Y is disposed between pixel 10R of pixel 10,1 and pixel 10L of pixel 10,3 adjacent to the pixel 10,1 on the direction of arrow X. A portion 47 of the pixel isolation region 4 extends in the direction opposite to the direction of arrow X from a middle portion of the extension direction of the pixel isolation region 4 to pixel 10R of pixel 10,1. When the pixel isolation region 4 and portion 47 are combined with portions 47 of the pixels 10,3 adjacent to the pixel 10,1 on the opposite side of the direction of arrow X, they form a cross shape in a plan view.

[0204] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the tenth embodiment.

[0205] [Operational Effects] According to the photodetector 1 of the twentieth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the tenth embodiment.

[0206] Furthermore, as shown in FIGS. 33 and 34 , the photodetector 1 includes a dark current prevention region 305 and a charge accumulation region 306. The photodetector 1 configured in this manner includes the dark current prevention region 305, thereby effectively suppressing or preventing dark current. Additionally, the photodetector 1 includes the charge accumulation region 306 disposed over almost the entire pixel 10, excluding the region of the transfer transistor TR, thereby facilitating the transfer of charges converted by the photoelectric conversion element PD to the transfer transistor TR. For example, a portion 47 of the pixel isolation region 4 is disposed in the middle of the pixel 10L in the Y direction. Across this portion 47, charges generated on the lower side of the pixel 10L in FIG. 33 are difficult to transfer to the transfer transistor TRL disposed above the pixel 10L. In the twentieth embodiment, the charge accumulation region 306 facilitates the transfer of charges to the transfer transistor TR.

[0207] 33 and 34 , in the photodetector 1, a part 47 of the pixel isolation region 4 extends between adjacent pixels 10 in the middle of the extension direction of the pixel isolation region 4. The end portions of this part 47 in the extension direction can be regarded as dividing points. This makes it possible to increase the number of dividing points of the pixel isolation region 4 in the direction of arrow X, thereby effectively suppressing or preventing anisotropic color mixing.

[0208] 21. Twenty-first embodiment A photodetector 1 according to a twenty-first embodiment of the present disclosure will be described with reference to Figures 35 and 36. The twenty-first embodiment describes an example in which the planar structure of the pixel 10 and the longitudinal cross-sectional configuration of the pixel 10 are changed in the photodetector 1 according to the twentieth embodiment.

[0209] [Device Configuration of Pixel 10 of Photodetector 1] FIG. 35 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. FIG. 36 shows an example of a specific longitudinal cross-sectional configuration of the pixel 10. As shown in FIGS. 35 and 36 , the photodetector 1 according to the twenty-first embodiment does not include the dividing portions 41 and 42 of the photodetector 1 according to the twentieth embodiment. A conductor region 54 is provided. The n-type semiconductor region 54 is used as the other main electrode of the transfer transistor TRR. In addition, in the pixel 10R, a p-type well contact region 6 is provided in the lower right corner, part of which is surrounded by the pixel isolation region 4. The p-type well contact region 6 is electrically connected to the p-type well region 302.

[0210] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the twentieth embodiment.

[0211] [Operational Effects] According to the photodetector 1 of the twenty-first embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the twentieth embodiment.

[0212] 22. Twenty-Second Embodiment A photodetector 1 according to a twenty-second embodiment of the present disclosure will be described with reference to Fig. 37. The twenty-second embodiment describes an example in which the planar structure and the longitudinal cross-sectional configuration of the pixel 10 in the photodetector 1 according to the twenty-first embodiment are changed.

[0213] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 37 shows an example of a specific planar configuration of pixel 10 of photodetector 1. As shown in Fig. 37, the photodetector 1 according to the 22nd embodiment includes a dividing portion 41 in the photodetector 1 according to the 21st embodiment. The dividing portion 42 is not included.

[0214] A detailed description will be given. A dividing portion 41 is disposed in the middle of the pixel isolation region 4 between pixel 10L and pixel 10R in the extension direction of the pixel isolation region 4 of pixel 10. An n-type semiconductor region 54 is disposed in the dividing portion 41. A part 47 of the pixel isolation region 4 is disposed in pixel 10L, and transfer transistors TRL1 and TRL2 are disposed in the direction of arrow Y centered on this part 47. A part 47 of the pixel isolation region 4 is disposed in pixel 10R, and transfer transistors TRR1 and TRR2 are disposed in the direction of arrow Y centered on this part 47. The n-type semiconductor region 54 is used as the other main electrode of each of transfer transistors TRL1, TRL2, TRR1, and TRR2.

[0215] On the other hand, in pixel 10L, p-type well contact regions 6 are arranged in the upper left corner and lower left corner, which are partially surrounded by the pixel isolation region 4. The p-type well contact regions 6 are electrically connected to the p-type well region 302. In pixel 10R, p-type well contact regions 6 are arranged in the upper right corner and lower right corner, which are partially surrounded by the pixel isolation region 4. The p-type well contact regions 6 are electrically connected to the p-type well region 302.

[0216] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the twenty-first embodiment.

[0217] [Operational Effects] According to the photodetector 1 of the twenty-second embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the twenty-first embodiment.

[0218] 37 , in the photodetector 1, a dividing portion 41 is provided in the pixel isolation region 4 between the pixel 10L and the pixel 10R of the pixel 10, and the other main electrode of the transfer transistor TRL1 or the like is disposed at the dividing portion 41. Therefore, it is possible to obtain the same effects as those obtained by the photodetector 1 according to the first embodiment.

[0219] 23. Twenty-third embodiment A photodetector 1 according to a twenty-third embodiment of the present disclosure will be described with reference to Fig. 38. The twenty-third embodiment describes an example in which the planar structure of the pixel 10 and the longitudinal cross-sectional configuration of the pixel 10 are changed in the photodetector 1 according to the twenty-second embodiment.

[0220] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 38 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. As shown in Fig. 38, the photodetector 1 according to the 23rd embodiment includes a dividing portion 42 in the photodetector 1 according to the 22nd embodiment.

[0221] The dividing points 42 are disposed at the four corners of the pixel isolation region 4 that surrounds the periphery of the pixel 10. A p-type well contact region 6 is disposed at the dividing points 42, and the p-type contact region is electrically connected to the p-type well region 302.

[0222] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the twenty-second embodiment.

[0223] [Operational Effects] According to the photodetector 1 of the twenty-third embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the twenty-second embodiment.

[0224] 24. Twenty-fourth embodiment A photodetector 1 according to a twenty-fourth embodiment of the present disclosure will be described with reference to Fig. 39. The twenty-fourth embodiment describes an example in which the planar structures of the pixels 10 and pixel circuits 20 in the photodetector 1 according to the first embodiment are changed.

[0225] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 39 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. As shown in Fig. 39, the photodetector 1 according to the twenty-fourth embodiment has a two-layer laminated structure in which the first base 1A and the second base 1B are combined into one base (see Fig. 4) in the photodetector 1 according to the first embodiment.

[0226] A detailed description will be given. The pixel 10L of the pixel 10 includes a photoelectric conversion element PDL and a transfer transistor TRL in a region surrounded by the pixel isolation region 4. A transistor Tr1 is also disposed in the same region surrounded by the pixel isolation region 4. The transistor Tr1 includes a gate insulating film (not shown), a gate electrode 56, and a pair of main electrodes 57. The gate electrode 56 is disposed on the second surface 30B of the p-type well region 302 (see FIG. 3 ) with a gate insulating film interposed therebetween. The pair of main electrodes 57 are disposed in the p-type well region and are formed of n-type semiconductor regions in this case.

[0227] The transistor Tr1 is formed as a reset transistor RST, an amplification transistor AMP, or a selection transistor SEL of the pixel circuit 20, and constitutes the pixel circuit 20.

[0228] The pixel 10R of the pixel 10 includes a photoelectric conversion element PDR and a transfer transistor TRR in a region surrounded by the pixel isolation region 4. A transistor Tr2 is also disposed in the same region surrounded by the pixel isolation region 4. Like the transistor Tr1, the transistor Tr2 includes a gate insulating film (not shown), a gate electrode 56, and a pair of main electrodes 57.

[0229] The transistor Tr2 is formed as a reset transistor RST, an amplification transistor AMP, or a selection transistor SEL of the pixel circuit 20, and constitutes the pixel circuit 20.

[0230] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0231] [Operational Effects] According to the photodetector 1 of the twenty-fourth embodiment, it is possible to obtain the same operational effects as those obtained by the photodetector 1 of the first embodiment.

[0232] 25. Twenty-fifth embodiment A photodetector 1 according to a twenty-fifth embodiment of the present disclosure will be described with reference to Fig. 40. The twenty-fifth embodiment describes an example in which the planar structures of the pixels 10 and pixel circuits 20 in the photodetector 1 according to the fourteenth embodiment are changed.

[0233] [Device Configuration of Pixel 10 of Photodetector 1] Fig. 40 shows an example of a specific planar configuration of a pixel 10 of the photodetector 1. As shown in Fig. 40, the photodetector 1 according to the 24th embodiment has a two-layer laminated structure in which the first substrate 1A and the second substrate 1B in the photodetector 1 according to the 14th embodiment are combined into a single substrate. In other words, the photodetector 1 according to the 24th embodiment is constructed by combining the photodetector 1 according to the 14th embodiment and the photodetector 1 according to the 24th embodiment.

[0234] A pixel 10L of the pixel 10 includes a photoelectric conversion element PDL, a transfer transistor TRL, and a transistor Tr1 in an area surrounded by the pixel isolation region 4. A pixel 10R of the pixel 10 includes a photoelectric conversion element PDR, a transfer transistor TRR, and a transistor Tr2 in an area surrounded by the pixel isolation region 4.

[0235] The transistor Tr1 and the transistor Tr2 are formed as a reset transistor RST, an amplification transistor AMP, or a selection transistor SEL of the pixel circuit 20, respectively, and form the pixel circuit 20.

[0236] The components other than those described above are the same as or substantially the same as the components of the photodetector 1 according to the fourteenth embodiment or the photodetector 1 according to the twenty-fourth embodiment.

[0237] [Effects] According to the photodetector 1 of the 24th embodiment, it is possible to obtain an effect that combines the effects obtained by the photodetector 1 of the 14th embodiment and the effects obtained by the photodetector 1 of the 24th embodiment.

[0238] 26. Other Embodiments The present technology is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the technology.

[0239] For example, among the photodetection devices according to the first to twenty-fifth embodiments, photodetection devices according to two or more of the embodiments may be combined.

[0240] A photodetector according to a first embodiment of the present disclosure includes a first pixel, a pixel isolation region, and a first transfer transistor. The first pixel includes a first photoelectric conversion element that converts light into an electric charge, disposed on a first surface of a substrate. The pixel isolation region extends along the periphery of the side of the first pixel, optically and electrically isolating the first pixel from the surrounding area. The first transfer transistor is disposed on a second surface of the substrate opposite the first surface, overlapping the first pixel, and electrically connecting one of the pair of first main electrodes to the first photoelectric conversion element. Additionally, in the photodetector, at least on the second surface of the substrate, a portion of the pixel isolation region in the extension direction is divided, and the other second main electrode of the pair of first transfer transistors is disposed at this division. With this photodetector configured in this manner, the other main electrode can be disposed overlapping the pixel isolation region in the extension direction, thereby reducing the ratio of the area occupied by the first transfer transistor disposed in the first pixel to the area occupied by the first pixel.

[0241] A photodetector according to a second embodiment of the present disclosure is the photodetector according to the first embodiment, further comprising a first well region and a first well contact region. A first transfer transistor is disposed in the first well region on the second surface side of the substrate. Another portion of the pixel isolation region in the extension direction is separated on at least the second surface side of the substrate, and the first well contact region is disposed at this separation. The first well contact region has the same conductivity type as the first well region and is electrically connected to the first well region. According to the photodetector configured in this manner, the first well contact region can be disposed so as to overlap with the pixel isolation region in the extension direction, thereby reducing the ratio of the area occupied by the first well contact region disposed in the first pixel to the area occupied by the first pixel.

[0242] A photodetector according to a third embodiment of the present disclosure is the photodetector according to the second embodiment, further comprising a second pixel, a pixel isolation region, and a second transfer transistor. The second pixel is adjacent to the first pixel on the first surface side of the substrate and includes a second photoelectric conversion element that converts light into an electric charge. The pixel isolation region extends along the periphery of the side surface of the second pixel, optically and electrically isolating the second pixel from the surrounding area. The second transfer transistor is disposed on the second surface side of the substrate so as to overlap the second pixel, and electrically connects one third main electrode of the pair to the second photoelectric conversion element. Additionally, in the photodetector, a portion of the pixel isolation region in the extension direction is divided at least on the second surface side of the substrate, and the other fourth main electrode of the pair of second transfer transistors is disposed at this division. With this photodetector configured in this manner, the other main electrode can be disposed so as to overlap the pixel isolation region in the extension direction, thereby reducing the ratio of the area occupied by the second transfer transistor disposed in the second pixel to the area occupied by the second pixel.

[0243] A photodetector according to a fourth embodiment of the present disclosure is the photodetector according to the third embodiment, further comprising a second well region and a second well contact region. The second well region has a second transfer transistor disposed on the second surface side of the substrate. The second well contact region is disposed at the separated portion of the pixel isolation region, at least on the second surface side of the substrate. The second well contact region has the same conductivity type as the second well region and is electrically connected to the second well region. With this photodetector configured in this manner, the second well contact region can be disposed so as to overlap with the pixel isolation region in the extension direction, thereby reducing the ratio of the area occupied by the second well contact region disposed in the second pixel to the area occupied by the second pixel.

[0244] In a photodetector according to a fifth embodiment of the present disclosure, the first pixel and the second pixel in the photodetector according to the fourth embodiment can be configured as phase difference detection pixels. A photodetector configured in this manner can detect light with an expanded dynamic range. Furthermore, the photodetector can reduce electric field-induced dark noise and improve the S / N ratio during low-illumination imaging. Furthermore, the photodetector can reduce anisotropic optical color mixing and reduce fixed pattern noise in bright images.

[0245] A photodetector according to a sixth embodiment of the present disclosure is the photodetector according to the fifth embodiment, further comprising an overflow path region. The overflow path region is disposed at a location where another portion of the pixel isolation region disposed between the first pixel and the second pixel is separated in the extension direction. The overflow path region allows excess charge to flow from one of the first photoelectric conversion element and the second photoelectric conversion element to the other. A photodetector configured in this manner can easily generate a transfer potential.

[0246] <Configuration of Present Technology> The present technology has the following configuration: According to the present technology having the following configuration, in a photodetector device, it is possible to reduce the ratio of the area occupied by a transfer transistor disposed in a pixel to the area occupied by the pixel.

[0247] (1) A photodetector comprising: a first pixel, on a first surface side of a substrate, and a first photoelectric conversion element that converts light into an electric charge; a pixel isolation region that extends along a periphery of a side surface of the first pixel and optically and electrically isolates the first pixel from the surrounding area; and a first transfer transistor that is arranged on a second surface side of the substrate opposite the first surface so as to overlap the first pixel, and one first main electrode of a pair of first transfer transistors is electrically connected to the first photoelectric conversion element, wherein a part of the extension direction of the pixel isolation region is divided at least on the second surface side of the substrate, and the other second main electrode of the pair of first transfer transistors is arranged at the divided location. (2) The photodetector according to (1), wherein a signal wiring that forms a floating diffusion is electrically connected to the other main electrode. (3) The photodetector according to (1) or (2), further comprising: a first well region on the second surface side of the substrate, in which the first transfer transistor is disposed; and a first well contact region, which has the same conductivity type as the first well region and is electrically connected to the first well region, and which is disposed at the separated portion, with another part of the pixel isolation region in the extension direction being separated on at least the second surface side of the substrate. (4) The photodetector according to (3), in which power supply wiring that supplies power to the first well region is electrically connected to the first well contact region. (5) The photodetector device according to any one of (1) to (4), comprising: a second pixel adjacent to the first pixel on the first surface side of the substrate, the second pixel having a second photoelectric conversion element disposed thereon for converting light into an electric charge; the pixel isolation region extending along a periphery of a side surface of the second pixel and optically and electrically isolating the second pixel from the surroundings; and a second transfer transistor disposed on the second surface side of the substrate so as to overlap the second pixel, the third main electrode of one of the pair being electrically connected to the second photoelectric conversion element; wherein a part of the extension direction of the pixel isolation region is divided at least on the second surface side of the substrate, and the other fourth main electrode of the pair of the second transfer transistor is disposed at the divided location.(6) The photodetector according to (5), further comprising: a second well region on the second surface side of the base, in which the second transfer transistor is disposed; and a second well contact region, the second well region having the same conductivity type as the second well region and electrically connected to the second well region, being disposed at the separated portion, wherein another part of the pixel isolation region in the extension direction is separated at least on the second surface side of the base. (7) The photodetector according to (6) or (7), in which the first pixel and the second pixel are capable of forming a phase difference detection pixel. (8) The photodetector according to (7), in which yet another part of the pixel isolation region disposed between the first pixel and the second pixel is separated in the extension direction, and an overflow path region for flowing excess charge from one of the first photoelectric conversion element and the second photoelectric conversion element to the other is disposed at the separated portion. (9) The photodetector according to any one of (5) to (8), wherein the second pixel is formed in a shape having optical symmetry with respect to the first pixel when viewed from the direction of incidence of light. (10) The photodetector according to any one of (5) to (9), wherein the pixel isolation region is disposed between the second main electrode and the fourth main electrode, and the second main electrode and the fourth main electrode are electrically isolated from each other. (11) The photodetector according to any one of (5) to (9), wherein the second main electrode is formed integrally with and shared by the fourth main electrode without the pixel isolation region therebetween. (12) The photodetector according to any one of (5) to (11), wherein the second main electrode and the fourth main electrode are each a first conductivity type semiconductor region, and the first well region, the first well contact region, the second well region, and the second well contact region are each a second conductivity type semiconductor region opposite to the first conductivity type. (13) The photodetector according to (9), wherein the first pixel and the second pixel have rectangular planar shapes when viewed from the direction of incidence of light, the second main electrode and the first well contact region are disposed on a diagonal line of the first pixel, and the fourth main electrode and the second well contact region are disposed on a diagonal line of the second pixel.(14) The photodetector according to (9), wherein the first pixel and the second pixel have rectangular planar shapes when viewed from the direction of incidence of light, and the second main electrode, the first well contact region, the fourth main electrode, and the second well contact region are arranged along an extension direction of the pixel isolation region arranged between the first pixel and the second pixel. (15) The photodetector according to (9), wherein the second main electrode and the fourth main electrode are arranged at one end side in the extension direction of the pixel isolation region arranged between the first pixel and the second pixel, and the first well contact region and the second well contact region are arranged at the other end side in the extension direction of the pixel isolation region. (16) The photodetector according to any one of (5) to (15), comprising: a first pixel isolation region including a pixel isolation region extending in a first direction in which the first pixels and the second pixels are arranged and a pixel isolation region extending in a second direction intersecting the first direction, and formed in an L shape when viewed from the direction of incidence of light; and a second pixel isolation region including a pixel isolation region extending in the first direction and formed in an I shape when viewed from the direction of incidence of light, wherein each of the first pixels and the second pixels is surrounded by the pixel isolation region which is a combination of the first pixel isolation region and the second pixel isolation region. (17) The photodetector according to any one of (5) to (16), wherein an optical lens is disposed on a first surface side of the base across the first pixels and the second pixels, and wherein one or more selected from the second main electrode, the fourth main electrode, the first well contact region, and the second well contact region are disposed on a periphery of the optical lens when viewed from the direction of incidence of light. (18) The photodetector according to any one of (5) to (17), wherein a plurality of the first transfer transistors are electrically connected in parallel and arranged, and a plurality of the second transfer transistors are electrically connected in parallel and arranged.(19) The photodetector according to any one of (5) to (18), wherein in the first pixel, a first dark current prevention layer is disposed on the second surface side of the base except for a region of the first transfer transistor, and a first charge accumulation layer is disposed between the first photoelectric conversion element and the first dark current prevention layer, and in the second pixel, a second dark current prevention layer is disposed on the second surface side of the base except for a region of the second transfer transistor, and a second charge accumulation layer is disposed between the second photoelectric conversion element and the second dark current prevention layer. (20) The photodetector according to any one of (1) to (18), wherein the pixel isolation region includes an isolation trench extending in a thickness direction of the base, and a buried body buried in the isolation trench.

[0248] This application claims priority based on Japanese Patent Application No. 2023-217237, filed on December 22, 2023, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0249] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur depending on design requirements and other factors, and are intended to be within the scope of the appended claims and their equivalents.

Claims

1. A photodetector comprising: a first pixel on a first surface side of a substrate, the first pixel having a first photoelectric conversion element that converts light into an electric charge; a pixel isolation region extending along the periphery of the side surface of the first pixel and optically and electrically isolating the first pixel from the surroundings; and a first transfer transistor arranged on a second surface side of the substrate opposite the first surface, overlapping the first pixel, the first main electrode of one of a pair being electrically connected to the first photoelectric conversion element; and wherein at least on the second surface side of the substrate, a portion of the extension direction of the pixel isolation region is interrupted, and the other second main electrode of the pair of the first transfer transistor is arranged at the interrupted location.

2. The photodetector according to claim 1, wherein the other main electrode is electrically connected to a signal wiring that forms a floating diffusion.

3. The photodetection device according to claim 1, further comprising: a first well region in which the first transfer transistor is disposed on the second surface side of the base; and a first well contact region, which is disposed at the separated location, at least on the second surface side of the base, another part of the extension direction of the pixel isolation region being separated, the first well contact region having the same conductivity type as the first well region and being electrically connected to the first well region.

4. The photodetector according to claim 3, wherein a power supply wiring for supplying power to said first well region is electrically connected to said first well contact region.

5. A photodetector as described in claim 1, comprising: a second pixel adjacent to the first pixel on the first surface side of the base, and including a second photoelectric conversion element that converts light into an electric charge; the pixel isolation region extending along a periphery of a side surface of the second pixel and optically and electrically isolating the second pixel from the surroundings; and a second transfer transistor arranged on the second surface side of the base so as to overlap the second pixel, the third main electrode of one of a pair being electrically connected to the second photoelectric conversion element, wherein a part of the extension direction of the pixel isolation region is interrupted at least on the second surface side of the base, and the other fourth main electrode of the pair of the second transfer transistor is arranged at the interrupted location.

6. The photodetection device according to claim 5, further comprising: a second well region in which the second transfer transistor is disposed on the second surface side of the substrate; and a second well contact region, which is disposed at the separated portion, at least on the second surface side of the substrate, another part of the extension direction of the pixel isolation region being separated, the second well contact region having the same conductivity type as the second well region and being electrically connected to the second well region.

7. The photodetection device according to claim 5, wherein the first pixel and the second pixel are capable of forming a phase difference detection pixel.

8. A photodetection device as described in claim 7, wherein a further part of the extension direction of the pixel isolation region arranged between the first pixel and the second pixel is divided, and an overflow path region that flows excess charge from one of the first photoelectric conversion element and the second photoelectric conversion element to the other is arranged at this division point.

9. The photodetection device according to claim 5, wherein the second pixel is formed in a shape having optical symmetry with respect to the first pixel when viewed from the direction of incidence of light.

10. The photodetection device according to claim 5, wherein the pixel isolation region is disposed between the second main electrode and the fourth main electrode, and the second main electrode and the fourth main electrode are electrically isolated from each other.

11. The photodetector according to claim 5, wherein the second main electrode is formed integrally with and shared by the fourth main electrode without the pixel isolation region therebetween.

12. The photodetector device according to claim 5, wherein each of the second main electrode and the fourth main electrode is a semiconductor region of a first conductivity type, and each of the first well region, the first well contact region, the second well region and the second well contact region is a semiconductor region of a second conductivity type opposite to the first conductivity type.

13. The photodetector according to claim 9, wherein, when viewed from the direction of incidence of light, the first pixel and the second pixel have a rectangular planar shape, the second main electrode and the first well contact region are disposed on a diagonal line of the first pixel, and the fourth main electrode and the second well contact region are disposed on a diagonal line of the second pixel.

14. The photodetection device according to claim 9, wherein, when viewed from the direction of incidence of light, the first pixel and the second pixel have a rectangular planar shape, and the second main electrode, the first well contact region, the fourth main electrode and the second well contact region are arranged along the extension direction of the pixel isolation region arranged between the first pixel and the second pixel.

15. The photodetection device according to claim 9, wherein the second main electrode and the fourth main electrode are arranged on one end side in the extension direction of the pixel isolation region arranged between the first pixel and the second pixel, and the first well contact region and the second well contact region are arranged on the other end side in the extension direction of the pixel isolation region.

16. The photodetection device according to claim 5, comprising: a first pixel isolation region including a pixel isolation region extending in a first direction in which the first pixels and the second pixels are arranged and a pixel isolation region extending in a second direction intersecting the first direction, the first pixel isolation region being formed in an L shape when viewed from the direction of incidence of light; and a second pixel isolation region including a pixel isolation region extending in the first direction and being formed in an I shape when viewed from the direction of incidence of light, each of the first pixels and the second pixels being surrounded by the pixel isolation region which is a combination of the first pixel isolation region and the second pixel isolation region.

17. The photodetector device according to claim 5, wherein an optical lens is disposed across the first pixel and the second pixel on a first surface side of the substrate, and one or more selected from the second main electrode, the fourth main electrode, the first well contact region and the second well contact region are disposed on the periphery of the optical lens when viewed from the direction of incidence of light.

18. The photodetector according to claim 5, wherein a plurality of the first transfer transistors are arranged and electrically connected in parallel, and a plurality of the second transfer transistors are arranged and electrically connected in parallel.

19. The photodetector according to claim 5, wherein in the first pixel, a first dark current prevention layer is disposed on the second surface side of the base except for the region of the first transfer transistor, and a first charge accumulation layer is disposed between the first photoelectric conversion element and the first dark current prevention layer; and in the second pixel, a second dark current prevention layer is disposed on the second surface side of the base except for the region of the second transfer transistor, and a second charge accumulation layer is disposed between the second photoelectric conversion element and the second dark current prevention layer.

20. The photodetector according to claim 1, wherein the pixel isolation region includes an isolation groove extending in the thickness direction of the base body, and a buried body buried in the isolation groove.

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