Light detection device and electronic device

Abstract

The present disclosure relates to a light detection device and an electronic device which make it possible to improve light detection characteristics. The light detection device comprises an element isolating part which is provided to a semiconductor substrate, a transistor which is provided to one side of the element isolating part, and a shield structure which is provided to another side of the element isolating part with respect to the transistor and which is fixed at a prescribed potential. The shield structure is provided along the element isolating part and between the transistor and a photoelectric conversion unit and is configured from a shield layer composed of a conductive material. The present technology can be applied to an imaging element, for example.

Description

Photodetection device and electronic apparatus

[0001] The present disclosure relates to a photodetection device and an electronic apparatus, and more particularly, to a photodetection device and an electronic apparatus that enable further improvement of photodetection characteristics.

[0002] Conventionally, in photodetection devices, techniques for improving photodetection characteristics have been developed by providing element isolation portions to suppress the effects caused by the operation of transistors.

[0003] For example, Patent Document 1 discloses a solid-state imaging device capable of more reliably suppressing the adverse effect of dark current components generated at the interface of an element isolation insulating film on a photoelectric conversion portion.

[0004] Japanese Unexamined Patent Publication No. 2013-131516

[0005] Meanwhile, there has been a demand for further improving the photodetection characteristics by enhancing the effect of suppressing the influence caused by the operation of transistors.

[0006] The present disclosure has been made in view of such circumstances, and aims to enable further improvement of photodetection characteristics.

[0007] A photodetection device according to one aspect of the present disclosure includes: an element isolation portion provided in a semiconductor substrate; a transistor provided on one side of the element isolation portion; and a shield structure provided on the other side of the element isolation portion relative to the transistor and fixed at a predetermined potential.

[0008] An electronic apparatus according to one aspect of the present disclosure includes the photodetection device having: an element isolation portion provided in a semiconductor substrate; a transistor provided on one side of the element isolation portion; and a shield structure provided on the other side of the element isolation portion relative to the transistor and fixed at a predetermined potential.

[0009] In one aspect of the present disclosure, a transistor is provided on one side of an element isolation portion provided in a semiconductor substrate, and a shield structure provided on the other side of the element isolation portion relative to the transistor is fixed at a predetermined potential.

[0010] This figure shows a first example of the configuration of a transistor structure provided in a photodetector to which this technology is applied. This figure shows a modified example of the pixel transistor in Figure 1. This figure shows a second example of the configuration of a transistor structure. This figure shows a modified example of the pixel transistor in Figure 3. This figure shows a third example of the configuration of a transistor structure. This figure shows a modified example of the pixel transistor in Figure 5. This figure shows a fourth example of the configuration of a transistor structure. This figure shows a modified example of the pixel transistor in Figure 7. This figure shows a fifth example of the configuration of a transistor structure. This figure shows a modified example of the pixel transistor in Figure 9. This figure shows a sixth example of the configuration of a transistor structure. This figure illustrates the manufacturing method of the transistor structure in Figure 1. This figure illustrates the manufacturing method of the transistor structure in Figure 1. This figure illustrates the manufacturing method of the transistor structure in Figure 1. This figure shows a seventh example of the configuration of a transistor structure. This figure shows an example of the layout of wiring connected to a contact electrode. This figure shows a contact electrode provided so as to penetrate the element isolation part. This figure shows an example of the application of the transistor structure to a connecting transistor. This figure shows a first modified example of the transistor structure in Figure 15. This figure shows a second modified example of the transistor structure in Figure 15. This figure shows a third modified example of the transistor structure in Figure 15. This figure illustrates the manufacturing method of the transistor structure in Figure 15. This figure illustrates the manufacturing method of the transistor structure in Figure 15. This figure illustrates the manufacturing method of the transistor structure in Figure 15. This is a diagram illustrating an example of the configuration of a photodetector and electronic equipment. This is a diagram showing an example of the use of the photodetector and electronic equipment. This is a block diagram showing an example of the schematic configuration of a vehicle control system. This is an explanatory diagram showing an example of the installation position of the external information detection unit and imaging unit. This is a diagram showing an example of the schematic configuration of an endoscopic surgery system. This is a block diagram showing an example of the functional configuration of a camera head and CCU.

[0011] The following describes in detail a specific embodiment of this technology, with reference to the drawings.

[0012] <First Example of Transistor Structure Configuration> Referring to Figures 1 and 2, a first example of a transistor structure configuration provided in a photodetector (for example, an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor) to which this technology is applied will be described.

[0013] Figure 1A shows a planar configuration example of the transistor structure 11. Figure 1B shows a cross-sectional configuration example of the transistor structure 11 along the dashed line A-A shown in Figure 1A, and Figure 1C shows a cross-sectional configuration example of the transistor structure 11 along the dashed line B-B shown in Figure 1A.

[0014] As shown in Figure 1, the transistor structure 11 is configured by arranging a transfer transistor 22, a pixel transistor 23-1, and a pixel transistor 23-2 on a semiconductor substrate 21 on which a photoelectric conversion unit PD is provided.

[0015] The semiconductor substrate 21 is provided with an element isolation section 31 for isolating the photoelectric conversion section PD. A transfer transistor 22 is positioned on the photoelectric conversion section PD side of the element isolation section 31, while pixel transistors 23-1 and 23-2 are positioned on the opposite side. Pixel transistors 23-1 and 23-2 are, for example, an amplification transistor that amplifies the charge photoelectrically converted by the photoelectric conversion section PD, a selection transistor that selects a pixel from which to read a pixel signal, a reset transistor that resets the charge accumulated in the FD (Floating Diffusion) section, and a connection transistor that connects a capacitor to the FD section.

[0016] The transfer transistor 22 is configured to have a gate electrode 41 that is laminated on the semiconductor substrate 21 via an insulating film. The lower end of a contact electrode 42, which is provided so as to penetrate the interlayer insulating film 71, is connected to the gate electrode 41, and wiring (not shown) that supplies a drive signal to drive the transfer transistor 22 is connected to the upper end of the contact electrode 42. The side surface of the contact electrode 42 is covered with a barrier metal 43.

[0017] The pixel transistor 23-1 is configured to have a gate electrode 51-1 that is laminated on the semiconductor substrate 21 via an insulating film. As shown in Figure 1B, the lower end of a contact electrode 52-1, which is provided to penetrate the interlayer insulating film 71, is connected to the gate electrode 51-1, and wiring 54-1 that supplies a drive signal to drive the pixel transistor 23-1 is connected to the upper end of the contact electrode 52-1. The side surface of the contact electrode 52-1 is covered with a barrier metal 53-1. Also, as shown in Figure 1B, a sidewall 73 is provided on the side surface of the gate electrode 51-1.

[0018] The pixel transistor 23-2 is configured with a gate electrode 51-2 that is laminated on the semiconductor substrate 21 via an insulating film. The lower end of a contact electrode 52-2, which is provided so as to penetrate the interlayer insulating film 71, is connected to the gate electrode 51-2, and wiring (not shown) that supplies a drive signal to drive the pixel transistor 23-2 is connected to the upper end of the contact electrode 52-2. The side surface of the contact electrode 52-2 is covered with a barrier metal 53-2.

[0019] When it is not necessary to distinguish between pixel transistor 23-1 and pixel transistor 23-2, they will be referred to as pixel transistor 23 as appropriate below, and the parts constituting pixel transistor 23-1 and pixel transistor 23-2 will also be referred to similarly.

[0020] The element isolation section 31 is constructed by embedding an insulator in a trench formed by excavating the semiconductor substrate 21, and as shown in Figures 1B and 1C, the upper end portion of the element isolation section 31 is formed to protrude from the light-receiving surface (the surface facing upward in Figure 1) of the semiconductor substrate 21.

[0021] As shown in Figure 1C, a silicon nitride film 72 is formed to cover the semiconductor substrate 21 and the element isolation portion 31. As shown in Figure 1B, in the area where the pixel transistor 23-1 is provided, the silicon nitride film 72 is also formed to cover the gate electrode 51-1 and sidewall 73 stacked on the semiconductor substrate 21 and the element isolation portion 31.

[0022] In the transistor structure 11, a shield layer 32 made of a conductive material is placed between the pixel transistor 23 and the photoelectric conversion unit PD along the element isolation section 31. For example, the shield layer 32 is provided so as to cover the element isolation section 31 and the semiconductor substrate 21 via a silicon nitride film 72 in a predetermined range extending from approximately the center of the element isolation section 31 toward the photoelectric conversion unit PD. As shown in Figure 1B, in the location where the pixel transistor 23-1 is provided, the shield layer 32 is provided so as to cover only the tip portion of the gate electrode 51-1 and the sidewall 73.

[0023] For example, the shield layer 32 can be made of polysilicon, similar to the gate electrode 41 and gate electrode 51, or it may be made of conductive materials such as tungsten, titanium, titanium nitride, tantalum, tantalum nitride, copper, or cobalt silicide.

[0024] Furthermore, as shown in Figure 1C, the lower end of a contact electrode 61, which is provided to penetrate the interlayer insulating film 71, is connected to the shield layer 32, and the side surface of the contact electrode 61 is covered by the barrier metal 62. A wiring 63 connected to the ground potential or a potential of 0V or less is connected to the upper end of the contact electrode 61, and the shield layer 32 is fixed to the ground potential or a potential of 0V or less.

[0025] In this way, the transistor structure 11 can reduce parasitic capacitance generated between the semiconductor substrate 21 on the photoelectric conversion unit PD side and the gate electrode 51 of the pixel transistor 23 by providing a shield layer 32 with a fixed potential (hereinafter referred to as the shielding effect). Due to this shielding effect, the transistor structure 11 can reduce the influence on the semiconductor substrate 21 on the photoelectric conversion unit PD side (for example, the semiconductor substrate 21 adjacent to the element isolation unit 31 or the surface in its vicinity) when the voltage applied to the gate electrode 51 of the pixel transistor 23 fluctuates. As a result, the generation of excited electrons due to the operation of the pixel transistor 23 (i.e., a decrease in hole concentration) can be suppressed, and the transistor structure 11 can suppress the deterioration of dark current and improve the photodetection characteristics. In this way, the transistor structure 11 can improve the photodetection characteristics through the shielding effect.

[0026] Furthermore, the shield layer 32 is positioned to extend into areas where the transfer transistor 22 and pixel transistor 23 are not provided (for example, in A of Figure 1, the area below pixel transistor 23-1, the area between pixel transistor 23-1 and pixel transistor 23-2, the area above pixel transistor 23-2, etc.). This improves the shielding effect compared to, for example, a configuration in which the shield layer 32 is provided only in the areas where the transfer transistor 22 and pixel transistor 23 are provided.

[0027] Furthermore, even in a configuration where a shielding layer 32 is provided between the pixel transistor 23-2 and the transfer transistor 22, the same shielding effect can be obtained.

[0028] Furthermore, the contact electrode 61 connected to the shield layer 32 is connected at a location where the shield layer 32 is flat, as shown in Figure 1C. This improves process stability compared to a configuration where the contact electrode 61 is connected at a location where the shield layer 32 is not flat, as shown in Figure 1B.

[0029] For example, in the transistor structure 11, by using a reset transistor, connection transistor, or selection transistor to which a high potential (VDD potential) is applied when the pixel transistor 23 is turned on, as the pixel transistor 23 to which the shield layer 32 is provided, the effect of suppressing dark current can be further enhanced.

[0030] Furthermore, the transistor structure 11 may be configured, for example, as shown in Figure 2A, using a shield layer 32-a that surrounds both corners of the tip side (photoelectric conversion unit PD side) of the pixel transistor 23-1 when viewed in plan. That is, the shield layer 32-a is formed to have portions of a predetermined length extending from both ends of a portion provided along the tip of the pixel transistor 23-1 (the portion extending in the vertical direction in Figure 2) toward the pixel transistor 23-1 side (the left side in Figure 2). By arranging a shield layer 32-a of this shape on the tip side of the pixel transistor 23-1, the shielding effect can be further improved.

[0031] Furthermore, the transistor structure 11 may also be configured using a shield layer 32-b with a shape such that, when the pixel transistor 23-1 is viewed in plan, it has a portion provided along the tip of the pixel transistor 23-1 and a portion provided for a predetermined length in a direction away from the pixel transistor 23-1 (towards the right in Figure 2). By using a shield layer 32-b with such a shape, the contact electrode 61 can be connected to a portion of the shield layer 32-b that is flat and located away from the pixel transistor 23-1. This improves process stability.

[0032] <Second Example of Transistor Structure Configuration> Referring to Figures 3 and 4, a second example of the configuration of a transistor structure provided in a photodetector to which this technology is applied will be described. In the transistor structure 11A shown in Figures 3 and 4, components common to the transistor structure 11 shown in Figures 1 and 2 above are denoted by the same reference numerals, and their detailed explanations are omitted.

[0033] Figure 3A shows a planar configuration example of the transistor structure 11A. Figure 3B shows a cross-sectional configuration example of the transistor structure 11A along the dashed line A-A shown in Figure 3A, and Figure 3C shows a cross-sectional configuration example of the transistor structure 11A along the dashed line B-B shown in Figure 3A.

[0034] As shown in Figure 3, the transistor structure 11A is configured by arranging a transfer transistor 22, a pixel transistor 23A-1, and a pixel transistor 23A-2 on a semiconductor substrate 21 on which a photoelectric conversion unit PD is provided. The transfer transistor 22 is positioned on the photoelectric conversion unit PD side with respect to the element isolation unit 31A, and the pixel transistors 23A-1 and 23A-2 are positioned on the opposite side.

[0035] Furthermore, the shield layer 32A, similar to the shield layer 32 in Figure 1, is positioned between the pixel transistor 23A and the photoelectric conversion unit PD along the element isolation section 31A, is made of a conductive material, and is fixed at ground potential or a potential of 0V or less.

[0036] Furthermore, in the transistor structure 11A, as shown in Figures 3B and 3C, the upper end surface of the element isolation portion 31A formed in the trench of the semiconductor substrate 21 is formed to be substantially coplanar with the light-receiving surface of the semiconductor substrate 21 (the surface facing upward in Figure 3). This makes it possible to create a flat configuration without a step (see Figure 1) at the boundary between the semiconductor substrate 21 and the element isolation portion 31A.

[0037] Then, in the transistor structure 11A, the upper end portion of the element isolation section 31A is processed so that it is at approximately the same height as the light-receiving surface of the semiconductor substrate 21, after which the gate electrode 51A-1 and the shield layer 32A are formed. Therefore, as shown in Figure 3B, the gate electrode 51A-1 of the pixel transistor 23A-1 can be formed in a flat shape. Similarly, as shown in Figure 3C, the shield layer 32A can be formed in a flat shape in areas where the transfer transistor 22 and the pixel transistor 23A are not provided.

[0038] As a result, the transistor structure 11A is configured to connect to the contact electrode 61 via a shield layer 32A formed in a flat shape, which contributes to greater process stability.

[0039] The transistor structure 11A configured in this way can achieve a shielding effect by providing a shielding layer 32A, similar to the transistor structure 11 in Figure 1, thereby improving the photodetection characteristics.

[0040] Furthermore, the transistor structure 11A may be configured, for example, as shown in Figure 4, using a shield layer 32A-a that surrounds both corners on the tip side (photoelectric conversion unit PD side) of the pixel transistor 23A-1 when viewed from above. By arranging a shield layer 32A-a of this shape on the tip side of the pixel transistor 23A-1, the shielding effect can be further improved.

[0041] <Third Example of Transistor Structure Configuration> Referring to Figures 5 and 6, a third example of the configuration of a transistor structure provided in a photodetector to which this technology is applied will be described. In the transistor structure 11B shown in Figures 5 and 6, components common to the transistor structure 11 shown in Figures 1 and 2 above are denoted by the same reference numerals, and their detailed explanations are omitted.

[0042] Figure 5A shows a planar configuration example of the transistor structure 11B. Figure 5B shows a cross-sectional configuration example of the transistor structure 11B along the dashed line A-A shown in Figure 5A, and Figure 5C shows a cross-sectional configuration example of the transistor structure 11B along the dashed line B-B shown in Figure 5A.

[0043] As shown in FIG. 5, the transistor structure 11B is configured such that a transfer transistor 22, a pixel transistor 23-1, and a pixel transistor 23-2 are arranged on a semiconductor substrate 21 provided with a photoelectric conversion unit PD. It has a configuration common to the transistor structure 11 in FIG. 1 in that the transfer transistor 22 is arranged on the photoelectric conversion unit PD side with respect to the element isolation unit 31, and the pixel transistor 23-1 and the pixel transistor 23-2 are arranged on the opposite side. Similarly to the shield layer 32 in FIG. 1, the shield layer 32B is arranged between the pixel transistor 23 and the photoelectric conversion unit PD along the element isolation unit 31, is made of a conductive material, and is fixed to a ground potential or a potential of 0 V or lower.

[0044] Then, in the transistor structure 11B, as shown in B of FIG. 5 and C of FIG. 5, a groove is formed in the semiconductor substrate 21 on the photoelectric conversion unit PD side of the element isolation unit 31 so as to extend along the side surface of the element isolation unit 31, and the shield layer 32B is formed such that a part thereof is embedded in the groove. That is, the transistor structure 11B differs from the transistor structure 11 in FIG. 1 in that the shield layer 32B is formed to have an embedded portion in the groove of the semiconductor substrate 21.

[0045] In A of FIG. 5, the thick broken line shown to overlap the shield layer 32B represents the embedded portion of the shield layer 32 embedded in the semiconductor substrate 21. That is, the embedded portion of the shield layer 32 is provided so as to extend to a region where the transfer transistor 22 and the pixel transistor 23 are not provided. Thereby, for example, the shield effect as described above can be improved as compared with a configuration in which the shield layer 32B is provided only in the region where the transfer transistor 22 and the pixel transistor 23 are provided.

[0046] The transistor structure 11B configured in this manner, similarly to the transistor structure 11 of FIG. 1, can obtain a shielding effect by providing the shield layer 32B, and can achieve improvement in photodetection characteristics. Furthermore, in the transistor structure 11B, by forming the shield layer 32B so as to have a buried portion in the groove portion of the semiconductor substrate 21, the shielding effect can be improved, and the photodetection characteristics can be further enhanced.

[0047] Note that, for example, as shown in FIG. 6, the transistor structure 11B may adopt a configuration using a shield layer 32B-a having a shape that surrounds the corners on both sides of the tip side (the photoelectric conversion unit PD side) of the pixel transistor 23-1 when the pixel transistor 23-1 is viewed in plan. The thick broken line shown to overlap the shield layer 32B-a in FIG. 6 represents the buried portion of the shield layer 32B-a that is buried in the semiconductor substrate 21. By arranging the shield layer 32B-a having such a shape on the tip side of the pixel transistor 23-1, the shielding effect can be further improved.

[0048] <Fourth Configuration Example of Transistor Structure> A fourth configuration example of the transistor structure provided in the photodetection device to which the present technology is applied will be described with reference to FIG. 7 and FIG. 8. Note that in the transistor structure 11C shown in FIG. 7 and FIG. 8, configurations common to those of the transistor structure 11 shown in FIG. 1 and FIG. 2 described above are assigned the same reference numerals, and detailed descriptions thereof are omitted.

[0049] A of FIG. 7 shows a planar configuration example of the transistor structure 11C. B of FIG. 7 shows a cross-sectional configuration example of the transistor structure 11C along the dashed-dotted line A-A shown in A of FIG. 7, and C of FIG. 7 shows a perspective configuration example of the pixel transistor 23-1.

[0050] As shown in Figure 7, the transistor structure 11C is configured with a transfer transistor 22, a pixel transistor 23-1, and a pixel transistor 23-2 arranged on a semiconductor substrate 21 on which a photoelectric conversion unit PD is provided. The transfer transistor 22 is arranged on the photoelectric conversion unit PD side with respect to the element isolation unit 31, and the pixel transistors 23-1 and 23-2 are arranged on the opposite side, which is a configuration common to the transistor structure 11 in Figure 1.

[0051] Furthermore, the transistor structure 11C differs from the transistor structure 11 in that a shield structure 64 is formed by a plurality of contact electrodes 61 arranged along the element isolation section 31. The shield structure 64 is positioned between the pixel transistor 23 and the photoelectric conversion section PD, and the sides of the contact electrodes 61 are covered with barrier metal 62.

[0052] As shown in Figure 7A, the shield structure 64 is configured such that a plurality of contact electrodes 61 are arranged at a predetermined arrangement density (for example, so that the contact electrodes 61 are spaced at intervals less than or equal to the diameter of each contact electrode 61).

[0053] Furthermore, the shield structure 64 is configured by arranging a plurality of contact electrodes 61 so as to extend into areas where the transfer transistors 22 and pixel transistors 23 are not provided. This makes it possible to improve the shielding effect as described above compared to a configuration in which, for example, the shield structure 64 is provided only in the areas where the transfer transistors 22 and pixel transistors 23 are provided.

[0054] For example, the contact electrode 61 is formed by a different process than the contact electrodes 42 and 52, and as shown in Figure 7B, it has a shape that extends to the depth of the silicon nitride film 72 deposited on the element isolation portion 31. For example, the silicon nitride film 72 can be used as a stopper to create an opening for forming the contact electrode 61.

[0055] Furthermore, as shown in Figure 7B, a wire 63 connected to the ground potential or a potential of 0V or less is connected to the upper end of the contact electrode 61, and the shield structure 64 is fixed to the ground potential or a potential of 0V or less.

[0056] The transistor structure 11C configured in this way can achieve a shielding effect similar to that of the transistor structure 11 in Figure 1 by providing a shielding structure 64 composed of multiple contact electrodes 61, thereby improving the photodetection characteristics.

[0057] Furthermore, the transistor structure 11C may be configured as shown in Figure 8, for example, by arranging the contact electrodes 61-1 to surround the corners on both sides of the tip side (photoelectric conversion unit PD side) of the pixel transistor 23-1 when viewed from above, thereby forming the shield structure 64-1. Similarly, the shield structure 64-2 may be configured by arranging the contact electrodes 61-2 to surround the corners on both sides of the tip side (photoelectric conversion unit PD side) of the pixel transistor 23-2 when viewed from above. By arranging such a shield structure 64 on the tip side of the pixel transistor 23, the shielding effect can be further improved.

[0058] <Fifth Configuration Example of Transistor Structure> Referring to Figures 9 and 10, a fifth configuration example of a transistor structure provided in a photodetector to which this technology is applied will be described. In the transistor structure 11D shown in Figures 9 and 10, components common to the transistor structure 11 shown in Figures 1 and 2 above are denoted by the same reference numerals, and their detailed explanations are omitted.

[0059] Figure 9A shows a planar configuration example of the transistor structure 11D. Figure 9B shows a cross-sectional configuration example of the transistor structure 11D along the dashed line A-A shown in Figure 9A, and Figure 9C shows a perspective view of the pixel transistor 23-1.

[0060] As shown in Figure 9, the transistor structure 11D is configured with a transfer transistor 22, a pixel transistor 23-1, and a pixel transistor 23-2 arranged on a semiconductor substrate 21 on which a photoelectric conversion unit PD is provided. The transfer transistor 22 is arranged on the photoelectric conversion unit PD side with respect to the element isolation unit 31, and the pixel transistors 23-1 and 23-2 are arranged on the opposite side, which is a configuration common to the transistor structure 11 in Figure 1.

[0061] Furthermore, the transistor structure 11D differs from the transistor structure 11 in Figure 1 in that the shield structure 64D is formed by contact electrodes 61D which are formed in a wall-like shape along the element isolation section 31. The shield structure 64D is positioned between the pixel transistor 23 and the photoelectric conversion section PD, and the side surface of the contact electrodes 61D is covered by barrier metal 62D.

[0062] Furthermore, the shield structure 64D is configured to extend into areas where the transfer transistor 22 and pixel transistor 23 are not provided. This improves the shielding effect compared to, for example, a configuration in which the shield structure 64D is provided only in areas where the transfer transistor 22 and pixel transistor 23 are provided.

[0063] For example, the contact electrode 61D is formed by a different process than the contact electrodes 42 and 52, and as shown in Figure 9B, it has a shape that is the depth to the silicon nitride film 72 deposited on the element isolation portion 31. For example, the silicon nitride film 72 can be used as a stopper to create an opening for forming the contact electrode 61D.

[0064] Furthermore, as shown in Figure 9B, a wire 63 connected to the ground potential or a potential of 0V or less is connected to the upper end of the contact electrode 61D, and the shield structure 64D is fixed to the ground potential or a potential of 0V or less.

[0065] The transistor structure 11D configured in this way can achieve a shielding effect similar to that of the transistor structure 11 in Figure 1 by providing a wall-shaped shield structure 64D, thereby improving the photodetection characteristics.

[0066] The transistor structure 11D may also be configured, for example, as shown in Figure 10, using a shield structure 64D-1 that surrounds both corners on the tip side (photoelectric conversion unit PD side) of the pixel transistor 23-1 when viewed from above. Similarly, the pixel transistor 23-2 may be configured using a shield structure 64D-2 that surrounds both corners on the tip side (photoelectric conversion unit PD side) of the pixel transistor 23-2 when viewed from above. By arranging such a shield structure 64D on the tip side of the pixel transistor 23, the shielding effect can be further improved.

[0067] <Sixth Configuration Example of Transistor Structure> Referring to Figure 11, a sixth configuration example of a transistor structure provided in a photodetector to which this technology is applied will be described. In the transistor structure 11E shown in Figure 11, components common to the transistor structure 11 shown in Figure 1 above are denoted by the same reference numerals, and their detailed explanations are omitted.

[0068] Figure 11A shows a planar configuration example of the transistor structure 11E. Figure 11B shows a cross-sectional configuration example of the transistor structure 11E along the dashed line A-A shown in Figure 11A.

[0069] Figure 11A shows the light-receiving surface of a light detector in which 16 pixels are arranged in an array, and the photoelectric conversion unit PD of each pixel is shown in a 4x4 array. The 2x4 array of pixels on the right constitutes an FD sharing unit 101-1 which shares the FD section, and the 2x4 array of pixels on the left constitutes an FD sharing unit 101-2 which shares the FD section.

[0070] The FD sharing unit 101-1 is equipped with eight transfer transistors 111-1 to 111-8, three amplification transistors 112-1 to 112-3, three selection transistors 113-1 to 113-3, one reset transistor 114-1, and one connection transistor 115-1, each provided for each photoelectric conversion unit PD. Similarly, the FD sharing unit 101-2 is equipped with eight transfer transistors 111-9 to 111-16, three amplification transistors 112-4 to 112-6, three selection transistors 113-4 to 113-6, one reset transistor 114-2, and one connection transistor 115-2, each provided for each photoelectric conversion unit PD.

[0071] As shown in the figure, the amplification transistor 112-2 of FD sharing unit 101-1 and the amplification transistor 112-5 of FD sharing unit 101-2 are arranged adjacent to each other via the element isolation unit 31. In this configuration, where different amplification transistors 112 are arranged adjacent to each other in FD sharing unit 101, there was a risk of crosstalk occurring due to parasitic capacitance between the amplification transistors 112.

[0072] Therefore, by applying a transistor structure 11E in which a shield layer 32E is placed between the amplification transistor 112-2 of FD sharing unit 101-1 and the amplification transistor 112-5 of FD sharing unit 101-2, the occurrence of such crosstalk can be suppressed. In other words, as shown in Figure 11B, a shield layer 32E made of a conductive material fixed to ground potential is placed between the gate electrode 121-2 constituting the amplification transistor 112-2 and the gate electrode 121-5 constituting the amplification transistor 112-5.

[0073] For example, as shown in Figure 11A, the shield layer 32E is provided to extend longer than the lengths of the amplifying transistors 112-2 and 112-5, along the element isolation section 31 for separating the photoelectric conversion section PD on the amplifying transistor 112-2 side from the photoelectric conversion section PD on the amplifying transistor 112-5 side. Also, as shown in Figure 11B, the shield layer 32E is formed to cover the end of the gate electrode 121-2 and the sidewall 122-2 provided on the side of the gate electrode 121-2, and the end of the gate electrode 121-5 and the sidewall 122-5 provided on the side of the gate electrode 121-5.

[0074] In this way, the transistor structure 11E can suppress crosstalk between adjacent amplification transistors 112-2 and 112-5 by providing a shield layer 32E with a fixed potential.

[0075] For example, as pixels become smaller, in a configuration where multiple amplification transistors 112 are arranged for a single pixel in order to ensure the transconductance gm of the amplification transistors 112, suppressing crosstalk between adjacent amplification transistors 112 becomes a layout constraint. Therefore, by providing the transistor structure 11E, the transconductance gm of the amplification transistors 112 can be easily ensured.

[0076] In addition to applying the transistor structure 11E to an element isolation portion 31 formed at a predetermined depth as shown in the figure, it is also possible to apply the transistor structure 11E to an element isolation portion 31 formed so as to penetrate the semiconductor substrate 21.

[0077] <Method for Manufacturing a Transistor Structure> The method for manufacturing the transistor structure 11 will be described with reference to Figures 12 to 14.

[0078] In the first step, as shown in the first step of Figure 12, a hard mask 131 is formed on the entire surface of the semiconductor substrate 21.

[0079] In the second step, the hard mask 131 is patterned according to the region where the element isolation section 31 is to be provided, and the semiconductor substrate 21 is etched to form trenches of a predetermined depth. Then, by filling the trenches with an insulator, the element isolation section 31 is formed as shown in the second step of Figure 12.

[0080] In the third step, the hard mask 131 is washed out, as shown in the third row of Figure 12.

[0081] In the fourth step, as shown in the first step of Figure 13, the gate electrode 51-1 and the sidewall 73 are formed, and a silicon nitride film 72 is deposited.

[0082] In the fifth step, as shown in the second step of Figure 13, a shield layer 32 is formed by laminating it onto the silicon nitride film 72 via an insulating film.

[0083] In the sixth step, as shown in the third step of Figure 13, an interlayer insulating film 71 with a thickness corresponding to the length of the contact electrode 52-1 is formed.

[0084] In the seventh step, etching is performed to form an opening for providing the contact electrode 52-1, which penetrates to the gate electrode 51-1, as shown in the first step of Figure 14.

[0085] In the eighth step, a contact electrode 52-1 is formed in the opening created in the seventh step, a wiring 54-1 is formed to connect to the upper end of the contact electrode 52-1, and then an interlayer insulating film 71 is deposited. This allows the transistor structure 11 to be constructed as shown in the second stage of Figure 14.

[0086] By the manufacturing method described above, a transistor structure 11 can be manufactured that provides a shielding effect through the shielding layer 32.

[0087] <Seventh Configuration Example of Transistor Structure> Referring to Figures 15 to 21, a seventh configuration example of a transistor structure provided in a photodetector to which this technology is applied will be described. In the transistor structure 11F shown in Figures 15 to 17, components common to the transistor structure 11 shown in Figure 1 above are denoted by the same reference numerals, and their detailed explanations are omitted.

[0088] Figure 15A shows planar configuration examples of transistor structures 11F-1 and 11F-2. Figure 15B shows a cross-sectional configuration example of transistor structure 11F-1 along the dashed line A-A shown in Figure 15A. The cross-sectional configuration of transistor structure 11F-2 is the same as that of transistor structure 11F-1, and is therefore not shown.

[0089] Figure 15A shows the light-receiving surface of a photodetector with 16 pixels arranged in an array, and the photoelectric conversion unit PD of each pixel is shown in a 4x4 array. The upper right 2x2 array of pixels has four transfer transistors 201-1 to 201-4 and shares FD unit 202-1. The lower right 2x2 array of pixels has four transfer transistors 201-5 to 201-8 and shares FD unit 202-2. The upper left 2x2 array of pixels has four transfer transistors 201-9 to 201-12 and shares FD unit 202-3. The lower left 2x2 array of pixels has four transfer transistors 201-13 to 201-16 and shares FD unit 202-4.

[0090] These 16 pixels share an amplification transistor 203, a selection transistor 204, and a reset transistor 205. Transistor structure 11F-1 is applied to the reset transistor 205, and transistor structure 11F-2 is applied to the amplification transistor 203. Below, an example of the configuration of transistor structure 11F-1 will be described, but transistor structure 11F-2 is configured similarly.

[0091] As shown in Figure 15B, the transistor structure 11F-1 is configured such that an element isolation section 31 is provided to separate the channel Ch and the photoelectric conversion section PD, which are provided on the semiconductor substrate 21 below the gate electrode 51, and a contact electrode 61F is provided to connect to the element isolation section 31. For example, the lower end of the contact electrode 61F is provided to extend to a predetermined depth relative to the element isolation section 31. In addition, a wiring 63 that supplies ground potential or a potential of 0V or less is connected to the upper end of the contact electrode 61F, and the contact electrode 61F is fixed at ground potential or a potential of 0V or less.

[0092] In this way, by configuring the transistor structure 11F-1 with contact electrodes 61F fixed to ground potential or a potential of 0V or less, the electric field generated between the gate electrode 51 and the photoelectric conversion unit PD can be shielded. This prevents weakening of pinning at the side wall of the element isolation unit 31, suppresses deterioration of dark current, and improves photodetection characteristics.

[0093] Figure 16 shows a planar layout example of the wiring connected to the contact electrode 61F (wiring 211, which corresponds to wiring 63 in Figure 15).

[0094] For example, as shown in Figure 16A, the wiring 211-1 connecting the contact electrode 61F-1 constituting the transistor structure 11F-1 and the contact electrode 61F-3 constituting the transistor structure 11F-2 is arranged in a layout that connects to the source power supply VSS. Similarly, the wiring 211-2 connecting the contact electrode 61F-2 constituting the transistor structure 11F-1 and the contact electrode 61F-4 constituting the transistor structure 11F-2 is arranged in a layout that connects to the source power supply VSS. By arranging the wiring 211-1 and wiring 211-2 in such a layout, the contact electrodes 61F-1 to 61F-4 can be fixed to ground potential.

[0095] Furthermore, as shown in Figure 16B, the wiring 211 connecting the contact electrode 61F-1 constituting the transistor structure 11F-1 and the contact electrode 61F-3 constituting the transistor structure 11F-2, as well as the contact electrode 61F-2 constituting the transistor structure 11F-1 and the contact electrode 61F-4 constituting the transistor structure 11F-2, is arranged in a layout that connects to a power supply (not shown) that applies a negative bias. By arranging the wiring 211 in this layout, the contact electrodes 61F-1 to 61F-4 can be fixed at a potential of 0V or less.

[0096] As shown in Figure 17, the transistor structure 11F may also be provided with contact electrodes 61F that penetrate the element isolation portion 31. In this case, it is preferable that the contact electrodes 61F do not connect to the P-well.

[0097] Furthermore, as shown in Figure 18, if a connecting transistor 206 for connecting a capacitor to the FD section 202 is provided in addition to the amplification transistor 203, selection transistor 204, and reset transistor 205, the transistor structure 11F-3 can be applied to the connecting transistor 206.

[0098] Referring to Figure 19, a first modified example of the transistor structure 11F will be described. In the transistor structure 11F-a shown in Figure 19, components common to the transistor structure 11F shown in Figure 15 are given the same reference numerals, and their detailed explanations are omitted.

[0099] As shown in Figure 19, transistor structure 11F-1a is applied to the reset transistor 205, and transistor structure 11F-2a is applied to the amplification transistor 203. Below, an example of the configuration of transistor structure 11F-1a will be described, but transistor structure 11F-2a is configured similarly.

[0100] The transistor structure 11F-1a differs from the transistor structure 11F-1 in Figure 15 in that, when viewed from above, it is composed of contact electrodes 61F-1a and 61F-2a that are formed in an elongated shape with a length corresponding to the area in which the gate electrode of the reset transistor 205 is provided, so as to be aligned with the side surface of the gate electrode of the reset transistor 205.

[0101] By configuring the transistor structure 11F-1a with the contact electrodes 61F-1a and 61F-2a formed in this manner, the effect of shielding the electric field generated between the gate electrode of the reset transistor 205 and the photoelectric conversion unit PD can be enhanced. Therefore, the transistor structure 11F-1a can suppress the deterioration of dark current and improve the photodetection characteristics.

[0102] Referring to Figure 20, a second modified example of the transistor structure 11F will be described. In the transistor structure 11F-b shown in Figure 20, components common to the transistor structure 11F shown in Figure 15 are given the same reference numerals, and their detailed explanations are omitted.

[0103] As shown in Figure 20, transistor structure 11F-1b is applied to the amplification transistor 203, the selection transistor 204, and the reset transistor 205.

[0104] The transistor structure 11F-1b differs from the transistor structure 11F-1 in Figure 15 in that, when viewed in plan, it is composed of contact electrodes 61F-1b and 61F-2b that are formed in an elongated shape corresponding to the area in which the amplification transistor 203, selection transistor 204, and reset transistor 205 are provided, along the semiconductor substrate 21 on which the amplification transistor 203, selection transistor 204, and reset transistor 205 are provided.

[0105] By configuring the transistor structure 11F-1b with the contact electrodes 61F-1b and 61F-2b formed in this manner, the effect of shielding the electric field generated between the gate electrodes of the amplification transistor 203, the selection transistor 204, and the reset transistor 205 and the photoelectric conversion unit PD can be enhanced. Therefore, the transistor structure 11F-1b can suppress the deterioration of dark current and improve the photodetection characteristics.

[0106] Referring to Figure 21, a third modified example of the transistor structure 11F will be described. In the transistor structure 11F-c shown in Figure 21, components common to the transistor structure 11F shown in Figure 15 are given the same reference numerals, and their detailed explanations are omitted.

[0107] As shown in Figure 21, transistor structure 11F-1c is applied to the reset transistor 205, and transistor structure 11F-2c is applied to the amplification transistor 203. Below, an example of the configuration of transistor structure 11F-1c will be described, but transistor structure 11F-2c is configured similarly.

[0108] Transistor structure 11F-1c differs from transistor structure 11F-1 in Figure 15 in that, when viewed from above, it is composed of a shield structure 64F-1c formed by arranging a plurality of contact electrodes 61F-1c along the side surface of the gate electrode of reset transistor 205, and a shield structure 64F-2c formed by arranging a plurality of contact electrodes 61F-2c.

[0109] By configuring the transistor structure 11F-1c with the shield structures 64F-1c and 64F-2c formed in this manner, the effect of shielding the electric field generated between the gate electrode of the reset transistor 205 and the photoelectric conversion unit PD can be enhanced. Therefore, the transistor structure 11F-1c can suppress the deterioration of dark current and improve the photodetection characteristics.

[0110] <Manufacturing Method for Transistor Structure> The manufacturing method for transistor structure 11F-1 will be described with reference to Figures 22 to 24.

[0111] In the 11th step, as shown in the first step of Figure 22, a hard mask 131 is formed on the entire surface of the semiconductor substrate 21.

[0112] In the twelfth step, the hard mask 131 is patterned according to the region where the element isolation section 31 is to be provided, and the semiconductor substrate 21 is etched to form a trench of a predetermined depth. Then, by filling the trench with an insulator, the element isolation section 31 is formed as shown in the second step of Figure 22.

[0113] In the 13th step, the hard mask 131 is washed out as shown in the third row of Figure 22.

[0114] In the 14th step, the gate electrode 51 and the sidewall 73 are formed as shown in the first step of Figure 23.

[0115] In the 15th step, as shown in the second step of Figure 23, an interlayer insulating film 71 with a thickness corresponding to the length of the contact electrode 61F is formed.

[0116] In the 16th step, etching is performed to form an opening for providing a contact electrode 52 that penetrates to the gate electrode 51, as shown in the third step of Figure 23, and to form openings for providing contact electrodes 61F-1 and 61F-2 that penetrate to the element isolation portion 31.

[0117] In the 17th step, etching is performed to excavate the element isolation portion 31 to a predetermined depth, as shown in the first step of Figure 24, thereby forming an opening for providing the contact electrodes 61F-1 and 61F-2.

[0118] In the 18th step, contact electrodes 52, 61F-1, and 61F-2 are formed. Then, wiring 54 is formed to connect to the upper end of contact electrode 52, wiring 63-1 is formed to connect to the upper end of contact electrode 61F-1, and wiring 63-2 is formed to connect to the upper end of contact electrode 61F-2. As a result, the transistor structure 11F-1 can be constructed as shown in the second row of Figure 24.

[0119] By the manufacturing method described above, a transistor structure 11F-1 can be manufactured that provides a shielding effect through the contact electrodes 61F-1 and 61F-2.

[0120] <Light detection device and electronic equipment> A light detection device equipped with the transistor structure 11 described above can be applied to various electronic devices such as imaging systems such as digital still cameras and digital video cameras, mobile phones equipped with imaging functions, or other devices equipped with imaging functions.

[0121] Figure 25 is a block diagram showing an example configuration of the light detection device 1012 and the electronic device 1001.

[0122] As shown in Figure 25, the electronic device 1001 includes an optical system 1011, a light detection device 1012, and a DSP (Digital Signal Processor) 1013. The DSP 1013, display device 1015, operating system 1016, memory 1017, recording device 1018, and power supply system 1019 are connected via a bus 1014, and it is capable of capturing still and moving images.

[0123] The optical system 1011 is composed of one or more lenses and guides the image light (incident light) from the subject to the light detection device 1012, and forms an image on the light-receiving surface (sensor part) of the light detection device 1012.

[0124] The photodetector 1012 is configured with a transistor structure 11 as described in one of the above-described configuration examples. Electrons are accumulated in the photodetector 1012 for a certain period of time in accordance with the image formed on the light-receiving surface via the optical system 1011. A signal corresponding to the electrons accumulated in the photodetector 1012 is then supplied to the DSP 1013.

[0125] The DSP 1013 performs various signal processing on the signal from the light detection device 1012 to acquire an image, and temporarily stores the image data in the memory 1017. The image data stored in the memory 1017 is recorded in the recording device 1018 or supplied to the display device 1015 to display the image. The operation system 1016 accepts various operations from the user and supplies operation signals to each block of the electronic device 1001, and the power supply system 1019 supplies the power necessary to drive each block of the electronic device 1001.

[0126] As shown in Figure 25, the light detection device 1012 is configured to include a pixel area 1102, a vertical drive circuit 1103, a column signal processing circuit 1104, a horizontal drive circuit 1105, an output circuit 1106, a control circuit 1107, a data output signal line 1108, and input / output terminals 1109.

[0127] The pixel region 1102 is a light-receiving surface that receives light focused by the optical system 1011. Multiple pixels 1101 are arranged in a matrix within the pixel region 1102. Each pixel 1101 is connected to a vertical drive circuit 1103 row by row via a horizontal signal line, and to a column signal processing circuit 1104 column by column via a vertical signal line. Each of the multiple pixels 1101 outputs a pixel signal at a level corresponding to the amount of light it receives, and an image of the subject to be imaged onto the pixel region 1102 is constructed from these pixel signals.

[0128] The vertical drive circuit 1103 sequentially supplies drive signals to each pixel 1101 via horizontal signal lines for driving (transferring, selecting, resetting, etc.) each pixel 1101 in each row of multiple pixels 1101 arranged in the pixel area 1102. The column signal processing circuit 1104 performs CDS (Correlated Double Sampling) processing on the pixel signals output from the multiple pixels 1101 via vertical signal lines 2103, thereby performing AD conversion of the pixel signals and removing reset noise.

[0129] The horizontal drive circuit 1105 sequentially supplies a drive signal to the column signal processing circuit 1104 for each row of multiple pixels 1101 arranged in the pixel area 1102, causing the column signal processing circuit 1104 to output the pixel signal to the data output signal line 1108. The output circuit 1106 amplifies the pixel signal supplied from the column signal processing circuit 1104 via the data output signal line 1108 at a timing according to the drive signal from the horizontal drive circuit 1105, and outputs it to the DSP 1013.

[0130] The control circuit 1107 controls the operation of each block of the light detection device 1012 by generating and supplying, for example, clock signals and control signals according to the drive cycle of each block of the light detection device 1012. The input / output terminal 1109 performs signal input and output between the light detection device 1012 and the DSP 1013.

[0131] In the electronic device 1001 configured in this way, by applying the above-described transistor structure 11 to the photodetector 1012, for example, dark current can be suppressed and the photodetection characteristics can be improved. As a result, the electronic device 1001 can improve imaging characteristics in the dark and enable the capture of higher-quality images.

[0132] Figure 26 shows an example of use using the light detection device 1012 or the electronic device 1001.

[0133] The light detection device 1012 or electronic device 1001 can be used in various cases for sensing light such as visible light, infrared light, ultraviolet light, and X-rays, for example, as follows.

[0134] - Devices that capture images for viewing purposes, such as digital cameras and portable devices with camera functions. - Devices used for traffic purposes, such as in-vehicle sensors that capture images of the front, rear, surroundings, and interior of a vehicle for safe driving such as automatic stopping and recognition of the driver's condition, surveillance cameras that monitor moving vehicles and roads, and distance measuring sensors that measure distances between vehicles. - Devices used in home appliances such as TVs, refrigerators, and air conditioners that capture user gestures and allow device operation according to those gestures. - Devices used for medical and healthcare purposes, such as endoscopes and devices that perform angiography using infrared light reception. - Devices used for security purposes, such as surveillance cameras for crime prevention and cameras for person recognition. - Devices used for beauty purposes, such as skin measuring devices that capture images of skin and microscopes that capture images of the scalp. - Devices used for sports purposes, such as action cameras and wearable cameras for sports use. - Devices used for agriculture, such as cameras that monitor the condition of fields and crops.

[0135] <Examples of application to mobile devices> The technology disclosed herein (this technology) can be applied to various products. For example, the technology disclosed herein may be implemented as a device mounted on any type of mobile device such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility devices, airplanes, drones, ships, and robots.

[0136] Figure 27 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile control system to which the technology described herein may be applied.

[0137] The vehicle control system 12000 comprises a plurality of electronic control units connected via a communication network 12001. In the example shown in Figure 27, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. The functional configuration of the integrated control unit 12050 is shown in the figure, which includes a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface 12053.

[0138] The drivetrain control unit 12010 controls the operation of devices related to the vehicle's drivetrain according to various programs. For example, the drivetrain control unit 12010 functions as a control device for a drivetrain generating device that generates driving force for the vehicle, such as an internal combustion engine or a drive motor; a drivetrain transmission mechanism that transmits driving force to the wheels; a steering mechanism that adjusts the steering angle of the vehicle; and a braking device that generates braking force for the vehicle.

[0139] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window system, or various lamps such as headlights, reverse lights, brake lights, turn signals, or fog lights. In this case, the body system control unit 12020 may receive radio waves transmitted from a portable device that replaces a key or signals from various switches. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock system, power window system, lamps, etc.

[0140] The external information detection unit 12030 detects information from outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the external information detection unit 12030. The external information detection unit 12030 causes the imaging unit 12031 to capture images of the outside of the vehicle and receives the captured images. Based on the received images, the external information detection unit 12030 may perform object detection processing such as detecting people, cars, obstacles, signs, or characters on the road surface, or distance detection processing.

[0141] The imaging unit 12031 is a light sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0142] The in-vehicle information detection unit 12040 detects information inside the vehicle. The in-vehicle information detection unit 12040 is connected to, for example, a driver status detection unit 12041 that detects the driver's state. The driver status detection unit 12041 includes, for example, a camera that captures images of the driver, and the in-vehicle information detection unit 12040 may calculate the driver's level of fatigue or concentration, or determine whether the driver is drowsy, based on the detection information input from the driver status detection unit 12041.

[0143] The microcomputer 12051 can calculate control target values ​​for the drive force generator, steering mechanism, or braking device based on information inside and outside the vehicle acquired by the external information detection unit 12030 or the internal information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing ADAS (Advanced Driver Assistance System) functions, including collision avoidance or impact mitigation, following driving based on distance between vehicles, maintaining vehicle speed, vehicle collision warning, or vehicle lane departure warning.

[0144] Furthermore, the microcomputer 12051 can perform cooperative control for purposes such as autonomous driving, where the vehicle drives autonomously without driver intervention, by controlling the drive force generating device, steering mechanism, or braking device, etc., based on information about the vehicle's surroundings acquired by the external information detection unit 12030 or the internal information detection unit 12040.

[0145] Furthermore, the microcomputer 12051 can output control commands to the body system control unit 12020 based on external information acquired by the external information detection unit 12030. For example, the microcomputer 12051 can control the headlights according to the position of a preceding or oncoming vehicle detected by the external information detection unit 12030, and perform coordinated control aimed at reducing glare, such as switching from high beams to low beams.

[0146] The audio-image output unit 12052 transmits at least one of audio and image output signals to an output device capable of visually or audibly notifying the vehicle occupants or those outside the vehicle of information. In the example in Figure 27, the output devices are exemplified as an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an onboard display and a head-up display.

[0147] Figure 28 shows an example of the installation position of the imaging unit 12031.

[0148] In Figure 28, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0149] The imaging units 12101, 12102, 12103, 12104, and 12105 are installed, for example, on the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield inside the vehicle 12100. The imaging unit 12101 installed on the front nose and the imaging unit 12105 installed on the upper part of the windshield inside the vehicle mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 installed on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 installed on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 installed on the upper part of the windshield inside the vehicle is mainly used for detecting preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, or lanes.

[0150] Figure 28 shows an example of the imaging ranges of imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of imaging unit 12101 located on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of imaging units 12102 and 12103 located on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of imaging unit 12104 located on the rear bumper or back door. For example, by superimposing the image data captured by imaging units 12101 to 12104, an overhead view image of the vehicle 12100 can be obtained.

[0151] At least one of the imaging units 12101 to 12104 may have a function for acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera consisting of multiple image sensors, or an image sensor having pixels for phase difference detection.

[0152] For example, the microcomputer 12051, based on distance information obtained from the imaging units 12101 to 12104, can determine the distance to each object within the imaging range 12111 to 12114 and the temporal change of this distance (relative speed to the vehicle 12100). In particular, it can extract the closest object on the vehicle 12100's path that is traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or more) as the preceding vehicle. Furthermore, the microcomputer 12051 can set a predetermined distance to be maintained before the preceding vehicle and perform automatic braking control (including follow-and-stop control) and automatic acceleration control (including follow-and-start control), etc. In this way, cooperative control aimed at autonomous driving, where the vehicle drives autonomously without driver intervention, can be performed.

[0153] For example, the microcomputer 12051 can use distance information obtained from imaging units 12101 to 12104 to classify and extract three-dimensional object data related to three-dimensional objects, such as motorcycles, passenger cars, large vehicles, pedestrians, utility poles, and other three-dimensional objects, and use this data for automatic obstacle avoidance. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the degree of risk of collision with each obstacle. If the collision risk is above a set value and there is a possibility of collision, the microcomputer 12051 can provide driving assistance to avoid collisions by outputting a warning to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or evasive steering via the drive system control unit 12010.

[0154] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared light. For example, the microcomputer 12051 can recognize pedestrians by determining whether or not pedestrians are present in the images captured by the imaging units 12101 to 12104. Such pedestrian recognition is performed, for example, by a procedure to extract feature points from the images captured by the imaging units 12101 to 12104 as infrared cameras, and a procedure to perform pattern matching on a series of feature points that indicate the contour of an object to determine whether or not it is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the imaging units 12101 to 12104 and recognizes a pedestrian, the audio-image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio-image output unit 12052 may also control the display unit 12062 to display an icon indicating a pedestrian at a desired position.

[0155] The above describes an example of a vehicle control system to which the technology described herein may be applied. The technology described herein can be applied, for example, to the imaging unit 12031 of the configuration described above. By applying the technology described herein to the imaging unit 12031, high-quality images can be captured, and for example, external information of the vehicle can be detected more accurately.

[0156] <Examples of application to endoscopic surgical systems> The technology disclosed herein (this technology) can be applied to various products. For example, the technology disclosed herein may be applied to endoscopic surgical systems.

[0157] Figure 29 is a diagram showing an example of a schematic configuration of an endoscopic surgical system to which the technology described herein (the technology) may be applied.

[0158] Figure 29 illustrates a surgeon (physician) 11131 performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgical system 11000. As shown in the figure, the endoscopic surgical system 11000 consists of an endoscope 11100, other surgical instruments 11110 such as a pneumoperitoneum tube 11111 and an energy treatment device 11112, a support arm device 11120 for supporting the endoscope 11100, and a cart 11200 equipped with various devices for endoscopic surgery.

[0159] The endoscope 11100 consists of a barrel 11101, the tip of which is inserted into the body cavity of the patient 11132 for a predetermined length, and a camera head 11102 connected to the base end of the barrel 11101. In the illustrated example, the endoscope 11100 is shown as a so-called rigid endoscope having a rigid barrel 11101, but the endoscope 11100 may also be configured as a so-called flexible endoscope having a flexible barrel.

[0160] An opening into which an objective lens is fitted is provided at the tip of the microscope tube 11101. A light source device 11203 is connected to the endoscope 11100, and the light generated by the light source device 11203 is guided to the tip of the microscope tube by a light guide extending inside the microscope tube 11101, and is irradiated through the objective lens towards the object to be observed inside the body cavity of the patient 11132. The endoscope 11100 may be a straight-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0161] The camera head 11102 contains an optical system and an image sensor. Reflected light from the object being observed (observation light) is focused onto the image sensor by the optical system. The image sensor converts the observation light into electrical signals, generating an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. This image signal is transmitted as RAW data to the camera control unit (CCU) 11201.

[0162] The CCU 11201 is composed of a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and other components, and comprehensively controls the operation of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102 and performs various image processing operations on that image signal, such as development processing (demosaic processing), to display an image based on that image signal.

[0163] The display device 11202 displays an image based on an image signal that has been processed by the CCU 11201, under control from the CCU 11201.

[0164] The light source device 11203 is composed of a light source such as an LED (light-emitting diode) and supplies illumination light to the endoscope 11100 when photographing the surgical area, etc.

[0165] The input device 11204 is an input interface for the endoscopic surgical system 11000. The user can input various types of information and instructions to the endoscopic surgical system 11000 via the input device 11204. For example, the user can input instructions to change the imaging conditions (type of light, magnification, focal length, etc.) of the endoscope 11100.

[0166] The treatment instrument control device 11205 controls the drive of the energy treatment instrument 11112 for purposes such as tissue cauterization, incision, or blood vessel sealing. The insufflation device 11206 injects gas into the body cavity of the patient 11132 via the insufflation tube 11111 to inflate the body cavity for the purpose of securing a field of view by the endoscope 11100 and securing the operator's workspace. The recorder 11207 is a device capable of recording various information related to the surgery. The printer 11208 is a device capable of printing various information related to the surgery in various formats such as text, images, or graphs.

[0167] The light source device 11203 that supplies illumination light to the endoscope 11100 when photographing the surgical area can be configured as a white light source consisting of, for example, an LED, a laser light source, or a combination thereof. When the white light source is configured as a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so the white balance of the captured image can be adjusted in the light source device 11203. In this case, it is also possible to capture images corresponding to each of the RGB colors in time-division by irradiating the observation target with laser light from each of the RGB laser light sources in time-division and controlling the drive of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter on the image sensor.

[0168] Furthermore, the light source device 11203 may be controlled to change the intensity of the light it outputs at predetermined time intervals. By controlling the drive of the image sensor of the camera head 11102 in synchronization with the timing of the change in light intensity, images can be acquired in time-division order, and these images can be combined to generate high dynamic range images without so-called black crushing and white clipping.

[0169] Furthermore, the light source device 11203 may be configured to supply light in a predetermined wavelength band corresponding to special light observation. In special light observation, for example, by utilizing the wavelength dependence of light absorption in body tissue and irradiating with narrow-band light compared to the irradiation light used during normal observation (i.e., white light), so-called narrow-band imaging is performed to image predetermined tissues such as blood vessels on the surface of mucosa with high contrast. Alternatively, in special light observation, fluorescence observation may be performed to obtain an image from fluorescence generated by irradiation with excitation light. In fluorescence observation, excitation light is irradiated onto body tissue and fluorescence from the body tissue is observed (autofluorescence observation), or a reagent such as indocyanine green (ICG) is injected into body tissue and excitation light corresponding to the fluorescence wavelength of the reagent is irradiated onto the body tissue to obtain a fluorescence image. The light source device 11203 may be configured to supply narrow-band light and / or excitation light corresponding to such special light observation.

[0170] Figure 30 is a block diagram showing an example of the functional configuration of the camera head 11102 and CCU 11201 shown in Figure 29.

[0171] The camera head 11102 includes a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other via a transmission cable 11400 so that they can communicate with each other.

[0172] The lens unit 11401 is an optical system provided at the connection point with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and then incident on the lens unit 11401. The lens unit 11401 is composed of a combination of multiple lenses, including a zoom lens and a focus lens.

[0173] The imaging unit 11402 may consist of one image sensor (a so-called single-chip type) or multiple image sensors (a so-called multi-chip type). If the imaging unit 11402 is configured as a multi-chip type, for example, each image sensor may generate image signals corresponding to RGB, and these may be combined to obtain a color image. Alternatively, the imaging unit 11402 may be configured to have a pair of image sensors for acquiring image signals for the right eye and left eye, respectively, corresponding to 3D (dimensional) display. By performing 3D display, the surgeon 11131 can more accurately grasp the depth of the biological tissue in the surgical area. In addition, if the imaging unit 11402 is configured as a multi-chip type, multiple lens units 11401 may be provided corresponding to each image sensor.

[0174] Furthermore, the imaging unit 11402 does not necessarily have to be located on the camera head 11102. For example, the imaging unit 11402 may be located inside the lens barrel 11101, directly behind the objective lens.

[0175] The drive unit 11403 is composed of actuators and, under control from the camera head control unit 11405, moves the zoom lens and focus lens of the lens unit 11401 along the optical axis by a predetermined distance. This allows the magnification and focus of the image captured by the imaging unit 11402 to be adjusted as appropriate.

[0176] The communication unit 11404 is composed of communication devices for sending and receiving various types of information with the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 as RAW data to the CCU 11201 via the transmission cable 11400.

[0177] Furthermore, the communication unit 11404 receives a control signal from the CCU 11201 to control the drive of the camera head 11102 and supplies it to the camera head control unit 11405. The control signal includes information about imaging conditions, such as information to specify the frame rate of the captured image, information to specify the exposure value at the time of imaging, and / or information to specify the magnification and focus of the captured image.

[0178] The imaging conditions such as frame rate, exposure value, magnification, and focus may be specified by the user as appropriate, or they may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 is equipped with so-called AE (Auto Exposure), AF (Auto Focus), and AWB (Auto White Balance) functions.

[0179] The camera head control unit 11405 controls the drive of the camera head 11102 based on the control signal received from the CCU 11201 via the communication unit 11404.

[0180] The communication unit 11411 is comprised of a communication device for sending and receiving various types of information with the camera head 11102. The communication unit 11411 receives image signals transmitted from the camera head 11102 via the transmission cable 11400.

[0181] Furthermore, the communication unit 11411 transmits control signals to the camera head 11102 to control the driving of the camera head 11102. Image signals and control signals can be transmitted by telecommunications, optical communications, etc.

[0182] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102.

[0183] The control unit 11413 performs various controls related to imaging the surgical area, etc., by the endoscope 11100, and the display of the images obtained from imaging the surgical area, etc. For example, the control unit 11413 generates a control signal to control the driving of the camera head 11102.

[0184] Furthermore, the control unit 11413 displays the captured image showing the surgical area, etc., on the display device 11202 based on the image signal processed by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition technologies. For example, the control unit 11413 can recognize surgical instruments such as forceps, specific biological sites, bleeding, mist when using the energy treatment device 11112, etc., by detecting the shape and color of the edges of objects included in the captured image. When the control unit 11413 displays the captured image on the display device 11202, it may use the recognition results to superimpose various surgical support information onto the image of the surgical area. By superimposing the surgical support information and presenting it to the surgeon 11131, the burden on the surgeon 11131 can be reduced, and the surgeon 11131 can proceed with the surgery reliably.

[0185] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable compatible with electrical signal communication, an optical fiber compatible with optical communication, or a composite cable thereof.

[0186] In the illustrated example, communication was performed via a wired connection using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may be performed wirelessly.

[0187] The above describes an example of an endoscopic surgical system to which the technology described herein may be applied. The technology described herein can be applied to, for example, the endoscope 11100 or the camera head 11102 (or its imaging unit 11402) among the configurations described above. By applying the technology described herein to the endoscope 11100 or the camera head 11102 (or its imaging unit 11402), high-quality images can be captured, and for example, the surgical site can be confirmed more accurately and reliably.

[0188] While an endoscopic surgical system has been described here as an example, the technology described herein may also be applied to other systems, such as microsurgical systems.

[0189] <Examples of Configuration Combinations> The technology can also take the following configurations: (1) A photodetector comprising: an element isolation section provided on a semiconductor substrate; a transistor provided on one side of the element isolation section; and a shield structure provided on the other side of the element isolation section relative to the transistor and fixed at a predetermined potential. (2) The photodetector according to (1) above, wherein the shield structure is provided between the transistor and the photoelectric conversion section along the element isolation section and is composed of a shield layer made of a conductive material. (3) The photodetector according to (2) above, wherein the contact electrode that supplies a predetermined potential to the shield layer is connected to a location where the shield layer is formed flat. (4) The photodetector according to (2) or (3) above, wherein the shield layer is shaped to surround the corners at both ends of the tip side of the transistor. (5) The photodetector according to any one of (2) to (4) above, wherein the upper end surface of the element isolation section is formed to be substantially flush with the surface of the semiconductor substrate, and the shield layer is formed in a flat shape. (6) The photodetector according to any one of (2) to (5) above, wherein a portion of the shield layer is embedded in a groove of the semiconductor substrate on the photoelectric conversion section side of the element isolation section. (7) The photodetector according to any one of (2) to (6) above, wherein the shield structure is composed of a plurality of contact electrodes arranged between the transistor and the photoelectric conversion section along the element isolation section. (8) The photodetector according to any one of (1) to (7) above, wherein the shield structure is composed of contact electrodes formed in a wall shape between the transistor and the photoelectric conversion section along the element isolation section. (9) The photodetector according to any one of (1) to (8) above, wherein a plurality of photoelectric conversion sections form an FD (Floating Diffusion) sharing unit, and in a configuration where different amplifying transistors are arranged adjacent to each other in the FD sharing unit, the shield structure is arranged between the amplifying transistors. (10) The photodetector according to (1) above, wherein the shield structure is composed of contact electrodes provided to extend to a predetermined depth relative to the element isolation section.(11) The photodetector according to (10), wherein the contact electrode is connected to a wiring that supplies a ground potential or a potential of 0V or less. (12) The photodetector according to (10) or (11), wherein the contact electrode is provided through the element isolation portion. (13) The photodetector according to any one of (10) to (12), wherein the shield structure is provided on an amplifying transistor that amplifies the charge photoelectrically converted in the photoelectric conversion portion and a reset transistor that resets the charge accumulated in the FD (Floating Diffusion) portion. (14) The photodetector according to (13), wherein the shield structure is provided on a connecting transistor that connects a capacitor to the FD portion. (15) The photodetector according to any one of (10) to (14), wherein the contact electrode is formed to a length corresponding to the area in which the gate electrode of the transistor is provided. (16) The photodetector according to any one of (10) to (15) above, wherein the contact electrode is formed along a semiconductor region where the plurality of transistors are provided, with a length corresponding to the range in which the plurality of transistors are provided. (17) An electronic device comprising a photodetector having an element isolation section provided on a semiconductor substrate, a transistor provided on one side of the element isolation section, and a shield structure provided on the other side of the element isolation section relative to the transistor and fixed at a predetermined potential.

[0190] It should be noted that this embodiment is not limited to the embodiment described above, and various modifications are possible without departing from the spirit of this disclosure. Furthermore, the effects described herein are merely illustrative and not limiting, and other effects may also exist.

[0191] 11 Transistor structure, 21 Semiconductor substrate, 22 Transfer transistor, 23 Pixel transistor, 31 Element isolation section, 32 Shielding layer, 41 Gate electrode, 42 Contact electrode, 43 Barrier metal, 51 Gate electrode, 52 Contact electrode, 53 Barrier metal, 54 Wiring, 61 Contact electrode, 62 Barrier metal, 63 Wiring, 64 Shielding structure, 71 Interlayer insulating film, 72 Silicon nitride film, 73 Sidewall

Claims

An element isolation section provided on a semiconductor substrate, A transistor provided on one side of the element isolation section, A shielding structure is provided on the other side of the element isolation portion relative to the transistor and is fixed at a predetermined potential. A light detection device equipped with the following features. 　 The shield structure is provided between the transistor and the photoelectric conversion unit so as to be aligned with the element isolation unit, and is composed of a shield layer made of a conductive material. The light detection device according to claim 1. 　 The contact electrode that supplies a predetermined potential to the shield layer is connected to a location where the shield layer is formed flat. The light detection device according to claim 2. 　 The shielding layer is shaped to surround the corners at both ends of the transistor's tip. The light detection device according to claim 2. 　 The upper end surface of the element isolation portion is formed to be substantially flush with the surface of the semiconductor substrate. The shield layer is formed in a flat shape. The light detection device according to claim 2. 　 A portion of the shielding layer is embedded in the groove of the semiconductor substrate on the photoelectric conversion side of the element isolation section. The light detection device according to claim 2. 　 The shield structure is composed of a plurality of contact electrodes arranged between the transistor and the photoelectric conversion unit along the element isolation section. The light detection device according to claim 1. 　 The shield structure is composed of contact electrodes formed in a wall-like manner between the transistor and the photoelectric conversion unit, along the element isolation portion. The light detection device according to claim 1. 　 In a configuration where multiple photoelectric conversion units share an FD (Floating Diffusion) section, and in which different amplification transistors are arranged adjacent to each other within the FD sharing unit, the shield structure is arranged between the amplification transistors. The light detection device according to claim 1. 　 The shield structure is composed of contact electrodes that extend to a predetermined depth relative to the element isolation portion. The light detection device according to claim 1. 　 The contact electrode is connected to a wiring that supplies ground potential or a potential of 0V or less. The light detection device according to claim 10. 　 The contact electrode is provided penetrating the element isolation portion. The light detection device according to claim 10. 　 The shield structure is provided in the amplification transistor that amplifies the charge converted photoelectrically in the photoelectric conversion section, and in the reset transistor that resets the charge accumulated in the FD (Floating Diffusion) section. The light detection device according to claim 10. 　 The shield structure is provided on the connecting transistor that connects the capacitor to the FD section. The light detection device according to claim 13. 　 The contact electrode is formed to have a length corresponding to the area in which the gate electrode of the transistor is provided. The light detection device according to claim 10. 　 The contact electrode is formed along the semiconductor region where the plurality of transistors are provided, with a length corresponding to the area where the plurality of transistors are provided. The light detection device according to claim 10. 　 An element isolation section provided on a semiconductor substrate, A transistor provided on one side of the element isolation section, A shielding structure is provided on the other side of the element isolation portion relative to the transistor and is fixed at a predetermined potential. An electronic device equipped with a light detection device.

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