Imaging device

Abstract

In order to provide an imaging device that can further suppress noise in pixel signals. Such an imaging device includes: a semiconductor substrate (30), the semiconductor substrate including a photoelectric conversion portion (31) configured to perform photoelectric conversion on incident light, or a charge holding portion (32) configured to hold charges photoelectrically converted by the photoelectric conversion portion; a field effect transistor provided on the photoelectric conversion portion or on the semiconductor substrate near the charge holding portion; a contact plug (26) extending from the gate electrode (25) of the field effect transistor in a direction perpendicular to one main surface of the semiconductor substrate; and a protrusion (27) extending from the contact plug in a plane direction of the one main surface of the semiconductor substrate.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of Japanese Priority Patent Application JP2019 - 188723, filed on October 15, 2019, the entire contents of which are incorporated herein by reference. Technical field

[0003] This disclosure relates to an imaging device. Background art

[0004] In recent years, the sensitivity of imaging devices has been increasing. Therefore, the influence of crosstalk between adjacent pixels caused by light reflection inside the imaging device has also been increasing.

[0005] Therefore, it has been proposed to provide a light - shielding film inside the imaging device to suppress stray light inside the imaging device (for example, Patent Document 1).

[0006] List of cited references

[0007] Patent documents

[0008] Patent Document 1: JP 2011 - 216970A Summary of the invention

[0009] Technical problem

[0010] Therefore, it is desirable to more effectively block the light reflected inside the imaging device so that no charge is generated by the internal reflected light other than the charge generated by the light from the object.

[0011] Therefore, it is desirable to provide an imaging device capable of further suppressing noise in pixel signals.

[0012] Technical solution to solve the problem

[0013] An imaging device according to an embodiment of the present disclosure includes: a semiconductor substrate including a photoelectric conversion portion configured to perform photoelectric conversion on incident light and / or a charge holding portion configured to hold charges photoelectrically converted by the photoelectric conversion portion; a field - effect transistor provided on the photoelectric conversion portion or provided on the semiconductor substrate near the charge holding portion; a contact plug extending from a gate electrode of the field - effect transistor in a direction perpendicular to a main surface of the semiconductor substrate; and a protruding portion extending from the contact plug in a in - plane direction of the main surface of the semiconductor substrate.

[0014] The imaging device according to an embodiment of the present disclosure includes: a semiconductor substrate including a photoelectric conversion portion configured to perform photoelectric conversion on incident light, a charge holding portion configured to accumulate charges photoelectrically converted by the photoelectric conversion portion, and a read circuit configured to read the charges; a light shielding layer provided on one main surface of the semiconductor substrate; a contact that penetrates the light shielding layer and extends in a direction perpendicular to the one main surface of the semiconductor substrate; and a contact wiring layer that electrically connects the contact to a source or a drain of a field effect transistor provided on the semiconductor substrate. The one main surface of the semiconductor substrate includes a charge accumulation region and a non-charge accumulation region. The charge accumulation region includes at least the photoelectric conversion portion and the charge holding portion, and the non-charge accumulation region includes the read circuit. The contact wiring layer extends to the non-charge accumulation region and is electrically connected to the contact in the non-charge accumulation region.

[0015] The imaging device according to an embodiment of the present disclosure can more effectively block reflected light from entering the photoelectric conversion portion, the charge holding portion, etc. In this way, the imaging device according to an embodiment of the present disclosure can suppress the generation of new charges caused by, for example, internal reflected light. Description of the Drawings

[0016] Figure 1 Figure 1 is a schematic explanatory diagram showing the overall configuration of an imaging device to which the technology according to the present disclosure is applied.

[0017] Figure 2 Figure 2 is a longitudinal cross-sectional view showing the pixel structure in the imaging device according to the first embodiment of the present disclosure.

[0018] Figure 3 Figure 3 is a longitudinal cross-sectional view showing the first structural example of the protrusion according to the same embodiment.

[0019] Figure 4A Figure 4A is a longitudinal cross-sectional view explaining the steps of the method for forming the protrusion according to the first structural example.

[0020] Figure 4B Figure 4B is a longitudinal cross-sectional view explaining the steps of the method for forming the protrusion according to the first structural example.

[0021] Figure 4C Figure 4C is a longitudinal cross-sectional view explaining the steps of the method for forming the protrusion according to the first structural example.

[0022] ​​​​​​​​​​​​​Figure 4D Figure 4D is a longitudinal cross-sectional view illustrating steps of a method for forming a protrusion according to a first configuration example.

[0023] Figure 5 Figure 5 is a longitudinal cross-sectional view showing a second configuration example of a protrusion according to the same embodiment.

[0024] Figure 6A Figure 6A is a longitudinal cross-sectional view illustrating steps of a method for forming a protrusion according to the second configuration example.

[0025] Figure 6B Figure 6B is a longitudinal cross-sectional view illustrating steps of a method for forming a protrusion according to the second configuration example.

[0026] Figure 6C Figure 6C is a longitudinal cross-sectional view illustrating steps of a method for forming a protrusion according to the second configuration example.

[0027] Figure 6D Figure 6D is a longitudinal cross-sectional view illustrating steps of a method for forming a protrusion according to the second configuration example.

[0028] Figure 6E Figure 6E is a longitudinal cross-sectional view illustrating steps of a method for forming a protrusion according to the second configuration example.

[0029] Figure 7 Figure 7 is a longitudinal cross-sectional view showing an example of an imaging device to which the technology according to the same embodiment is applicable.

[0030] Figure 8 Figure 8 is a longitudinal cross-sectional view showing an example of an imaging device to which the technology according to the same embodiment is applicable.

[0031] Figure 9 Figure 9 is a longitudinal cross-sectional view showing an example of an imaging device to which the technology according to the same embodiment is applicable.

[0032] Figure 10 Figure 10 is a longitudinal cross-sectional view showing an example of an imaging device to which the technology according to the same embodiment is applicable.

[0033] Figure 11 Figure 11 is a plan view showing an example of a pixel of an imaging device according to a second embodiment of the present disclosure.​​​​​​​​​​​​​​​​​​​​​​​

[0034] Figure 12 Figure 12 is a longitudinal cross-sectional view showing a cross-sectional structure taken along the cutting line C-CC in Figure 11 .

[0035] Figure 13 Figure 13 is a longitudinal cross-sectional view showing a modified example of the cross-sectional structure shown in Figure 12 .

[0036] Figure 14A Figure 14A is a longitudinal cross-sectional view illustrating the steps of a first method for forming a contact wiring layer.

[0037] Figure 14B Figure 14B is a longitudinal cross-sectional view illustrating the steps of a first method for forming a contact wiring layer.

[0038] Figure 14C Figure 14C is a longitudinal cross-sectional view illustrating the steps of a first method for forming a contact wiring layer.

[0039] Figure 14D Figure 14D is a longitudinal cross-sectional view illustrating the steps of a first method for forming a contact wiring layer.

[0040] Figure 14E Figure 14E is a longitudinal cross-sectional view illustrating the steps of a first method for forming a contact wiring layer.

[0041] Figure 14F Figure 14F is a longitudinal cross-sectional view illustrating the steps of a first method for forming a contact wiring layer.

[0042] Figure 14G Figure 14G is a longitudinal cross-sectional view illustrating the steps of a first method for forming a contact wiring layer.

[0043] Figure 14H Figure 14H is a longitudinal cross-sectional view illustrating the steps of a first method for forming a contact wiring layer.

[0044] Figure 15A Figure 15A is a longitudinal cross-sectional view illustrating the steps of a second method for forming a contact wiring layer.

[0045] Figure 15B Figure 15B is a longitudinal cross-sectional view illustrating the steps of a second method for forming a contact wiring layer. ​​​​​​​​​​​​​​​​​​​​​​​​

[0046] Figure 15C Figure 15C is a longitudinal cross-sectional view showing the steps of a second method for forming a contact wiring layer.

[0047] Figure 15D Figure 15D is a longitudinal cross-sectional view showing the steps of a second method for forming a contact wiring layer.

[0048] Figure 15E Figure 15E is a longitudinal cross-sectional view showing the steps of a second method for forming a contact wiring layer.

[0049] Figure 15F Figure 15F is a longitudinal cross-sectional view showing the steps of a second method for forming a contact wiring layer.

[0050] Figure 16 Figure 16 is a longitudinal cross-sectional view showing an example of an imaging device to which the technology according to the same embodiment is applied.

[0051] Figure 17 Figure 17 is a longitudinal cross-sectional view showing an example of an imaging device to which the technology according to the same embodiment is applied.

[0052] Figure 18 Figure 18 is a longitudinal cross-sectional view showing an example of an imaging device to which the technology according to the same embodiment is applied.

[0053] Figure 19 Figure 19 is a block diagram showing an example of a schematic configuration of an imaging system including an imaging device according to the first or second embodiment of the present disclosure.

[0054] Figure 20 Figure 20 shows an example of a flowchart of an imaging operation performed by the imaging system shown by Figure 19 .

[0055] Figure 21 Figure 21 is a block diagram showing an example of a schematic configuration of a vehicle control system.

[0056] Figure 22 Figure 22 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit.

[0057] Figure 23 Figure 23 is a diagram showing an example of a schematic configuration of an endoscopic surgical system.​​​​​​​​​​​​​​​​​​​​​​​​

[0058] Figure 24 Figure 24 is a block diagram showing an example of the functional configuration of a camera and a CCU. Detailed Embodiments

[0059] Embodiments according to the present disclosure will be described in detail below with reference to the accompanying drawings. The embodiments described below are specific examples of the present disclosure. The technology according to the present disclosure is not limited to the following methods. In addition, the arrangement, dimensions, and dimensional ratios of the respective constituent elements shown in the respective drawings of the present disclosure are not limited to those shown in the respective drawings.

[0060] Note that the description will be made in the following order.

[0061] 1. Overall Configuration of the Imaging Device

[0062] 2. First Embodiment

[0063] 2.1 Pixel Configuration

[0064] 2.2 Example of the Structure of the Protrusion

[0065] 2.3 Variation

[0066] 3. Second Embodiment

[0067] 3.1 Pixel Configuration

[0068] 3.2 Example of the Structure of the Contact Wiring Layer

[0069] 3.3 Method of Forming the Contact Wiring Layer

[0070] 3.4 Variation

[0071] 4. Application Example

[0072] <1. Overall Configuration of the Imaging Device>

[0073] First, reference will be made to Figure 1 describe the overall configuration of an imaging device to which the technology according to the present disclosure is applied. Figure 1 is a schematic explanatory diagram showing the overall configuration of an imaging device to which the technology according to the present disclosure is applied.

[0074] As Figure 1 shown, for example, an imaging device 1 to which the technology according to the present disclosure is applied includes: a pixel array unit 3 (wherein pixels 2 are two-dimensionally arranged in a matrix), a vertical drive circuit 4, a column signal processing circuit 5, a horizontal drive circuit 6, an output circuit 7, and a control circuit 8.

[0075] ​​For example, the pixel array unit 3, the vertical driving circuit 4, the column signal processing circuit 5, the horizontal driving circuit 6, the output circuit 7, and the control circuit 8 are provided on a semiconductor substrate such as silicon (Si). The pixel array unit 3, the vertical driving circuit 4, the column signal processing circuit 5, the horizontal driving circuit 6, the output circuit 7, and the control circuit 8 may be provided on one semiconductor substrate, or may be divided into two or more groups and provided on two or more semiconductor substrates, with one group provided on each semiconductor substrate.

[0076] Each pixel 2 includes a photoelectric conversion section and a pixel circuit that converts the charge generated by the photoelectric conversion section into a pixel signal. For example, the photoelectric conversion section includes a photodiode. For example, the pixel circuit includes four MOSFETs (metal-oxide-semiconductor field-effect transistors), such as a transfer transistor, an amplification transistor, a selection transistor, and a reset transistor.

[0077] In addition, each pixel 2 may further include a charge holding section for implementing a global shutter operation. The global shutter operation is a shutter operation in which all pixels 2 effective for imaging start exposure simultaneously and end exposure simultaneously. The charge holding section can temporarily hold the charge photoelectrically converted by the exposure performed simultaneously for all pixels before extracting the pixel signal from the corresponding pixel 2.

[0078] Note that the pixel 2 may have a pixel sharing structure. The pixel sharing structure is a structure in which part or all of the pixel circuit is shared by a plurality of adjacent pixels 2. For example, a plurality of adjacent pixels 2 may share an amplification transistor, a selection transistor, and a reset transistor. In this case, a plurality of adjacent pixels 2 each include a photodiode, a transfer transistor, one floating diffusion section shared by the plurality of adjacent pixels 2, one amplification transistor shared in a similar manner, one selection transistor shared in a similar manner, and one reset transistor shared in a similar manner.

[0079] The control circuit 8 controls the operations of the respective units of the imaging device 1. Specifically, the control circuit 8 generates a clock signal and a control signal based on a vertical synchronization signal, a horizontal synchronization signal, and a main clock. The clock signal and the control signal are operation references for the vertical driving circuit 4, the column signal processing circuit 5, the horizontal driving circuit 6, etc. In addition, the control circuit 8 outputs the generated clock signal and control signal to the vertical driving circuit 4, the column signal processing circuit 5, the horizontal driving circuit 6, etc.

[0080] For example, the vertical driving circuit 4 includes a shift register and the like. The vertical driving circuit 4 selects the pixel driving wirings 10, and supplies a pulse signal to the selected pixel driving wirings 10 in units of rows to drive the pixels 2. Specifically, the vertical driving circuit 4 sequentially and selectively scans each pixel 2 included in the pixel array unit 3 in the vertical direction in units of rows. In this way, the vertical driving circuit 4 can extract a pixel signal corresponding to the amount of photoelectrically converted charge from each pixel 2, and supply the pixel signal to the column signal processing circuit 5.

[0081] The column signal processing circuit 5 is provided for each column of pixels 2 in the pixel array unit 3, and the column signal processing circuit 5 performs noise removal processing and the like on the pixel signals output from the pixels 2 for each column of pixels 2. For example, each column signal processing circuit 5 can perform correlated double sampling (CDS) processing for removing fixed pattern noise unique to the pixels 2 and analog-to-digital (AD) conversion processing and the like on the pixel signals.

[0082] For example, the horizontal driving circuit 6 includes a shift register and the like. The horizontal driving circuit 6 sequentially outputs horizontal scanning pulses to sequentially select each column signal processing circuit 5, and causes each selected column signal processing circuit 5 to output a pixel signal to the horizontal signal line 11.

[0083] The output circuit 7 outputs the pixel signals sequentially supplied from each column signal processing circuit 5 via the horizontal signal line 11 to the outside of the imaging device 1. For example, the output circuit 7 can perform various digital signal processing and the like on the pixel signals supplied from each column signal processing circuit 5, such as buffering, black level adjustment, and column difference correction, and then output the signal-processed pixel signals to the outside of the imaging device 1.

[0084] The imaging device 1 having the above-described configuration is a so-called column AD type complementary MOS (CMOS) image sensor, in which a column signal processing circuit 5 for performing CDS processing and AD conversion processing is provided for each column of pixels 2.

[0085] For example, the technology according to the present disclosure is applicable to the imaging device 1 having the above-described configuration. According to the technology of the present disclosure, the imaging device 1 can suppress the stray light generated inside the imaging device 1 from entering the photoelectric conversion unit or the charge holding unit by effectively blocking the stray light. According to this configuration, in the imaging device 1 to which the technology according to the present disclosure is applied, crosstalk and the like between adjacent pixels 2 can be further suppressed.

[0086] <2. First Embodiment>

[0087] (2.1. Pixel Structure)

[0088] Next, with reference to Figure 2Describe the structure of pixel 2 in the imaging device 1 according to the first embodiment of the present disclosure. Figure 2 It is a longitudinal cross-sectional view showing the structure of pixel 2 in the imaging device 1 according to the present embodiment.

[0089] As Figure 2 shown, the imaging device 1 includes, for example, a semiconductor substrate 30 and a multilayer wiring layer 20.

[0090] The semiconductor substrate 30 is a substrate including a semiconductor such as silicon. For example, the semiconductor substrate 30 includes a photoelectric conversion part (PD) and a charge holding part (MEM) 32 for each pixel 2. For example, the photoelectric conversion part 31 and the charge holding part 32 may include a second conductivity type (e.g., n-type) region provided in a first conductivity type (e.g., p-type) region of the semiconductor substrate 30.

[0091] The photoelectric conversion part 31 is, for example, a photodiode, and generates charges by photoelectrically converting the light incident on pixel 2. In addition, the charge holding part 32 is a region capable of holding the charges generated by the photoelectric conversion part 31. The charge holding part 32 can temporarily hold the charges generated by the photoelectric conversion part 31 during the period from sequentially driving pixel 2 to reading out the pixel signal. Therefore, the imaging device 1 can achieve a global shutter operation in which all pixels are simultaneously exposed by using the charge holding part 32 provided for each pixel 2.

[0092] The multilayer wiring layer 20 is provided on one main surface of the semiconductor substrate 30 on the side opposite to the light receiving surface side. For example, the multilayer wiring layer 20 includes a plurality of wiring layers 21, a plurality of interlayer insulating layers 22 for insulating the plurality of wiring layers 21 in the stacking direction, and a plurality of contact plugs 23 provided in such a way as to penetrate the interlayer insulating layer 22 and electrically connect the plurality of wiring layers 21. For example, the multilayer wiring layer 20 includes transistors Tr such as transfer transistors, amplification transistors, selection transistors, and reset transistors included in a pixel circuit, and wirings for electrically connecting the respective transistors Tr.

[0093] In addition, below the region where the charge holding part 32 is provided in the semiconductor substrate 30, a gate electrode 25 of a transfer transistor for controlling the transfer of charges to or from the charge holding part 32 is provided in the multilayer wiring layer 20. The gate electrode 25 of the transfer transistor is electrically connected to the wiring layer 21 via the contact plug 26, and can control the transfer of charges to or from the charge holding part 32 by using the voltage applied from the wiring layer 21.

[0094] When stray light or the like enters the charge holding section 32 which temporarily holds charges, the amount of charge held in the charge holding section 32 may increase due to the generation of new charges in the charge holding section 32. Therefore, in the imaging device 1, light entering the charge holding section 32 is suppressed by providing a light shielding structure 33 in the semiconductor substrate 30 and a wiring light shielding film 24 in the multilayer wiring layer 20.

[0095] For example, the light shielding structure 33 includes a first light shielding film 33A, a second light shielding film 33B, and a third light shielding film 33C, and the light shielding structure 33 is provided to cover the region where the charge holding section 32 is provided with a light shielding metal such as tungsten (W).

[0096] The first light shielding film 33A is provided between the charge holding section 32 and the photoelectric conversion section 31 and extends in the thickness direction of the semiconductor substrate 30. The first light shielding film 33A is provided to prevent light that has passed through the semiconductor substrate 30 without being absorbed by the photoelectric conversion section 31 from entering the charge holding section 32.

[0097] The second light shielding film 33B is provided to extend in the in-plane direction on one main surface of the semiconductor substrate 30 corresponding to the region where the charge holding section 32 is provided. The second light shielding film 33B can prevent light that has entered from the light receiving surface side of the semiconductor substrate 30 from directly or indirectly entering the charge holding section 32.

[0098] The third light shielding film 33C is provided between the photoelectric conversion section 31 and the charge holding section 32 of the adjacent pixel 2. The third light shielding film 33C can prevent light from entering the charge holding section 32 after the light enters the adjacent pixel 2 and passes through the semiconductor substrate 30.

[0099] The wiring light shielding film 24 is provided to cover the gate electrode 25 of the transfer transistor from the multilayer wiring layer 20 side. The wiring light shielding film 24 can prevent light that has passed through the semiconductor substrate 30 without being absorbed by the photoelectric conversion section 31 and is reflected on the wiring layer 21 from entering the charge holding section 32 from the multilayer wiring layer 20 side.

[0100] The wiring light shielding film 24 further includes an opening 24A for connecting the contact plug 26 to the gate electrode 25 of the transfer transistor. In this case, light reflected on the wiring layer 21 may enter the charge holding section 32 through the opening 24A through which the contact plug 26 passes.

[0101] Therefore, according to this embodiment, a protrusion 27 is provided on a contact plug 26 electrically connected to a gate electrode 25 of a transfer transistor. The protrusion 27 protrudes in the in-plane direction of the semiconductor substrate 30 and covers the opening 24A. Specifically, the protrusion 27 is provided in a region larger than the region where the opening 24A is formed, and is provided to partially overlap with the region where the wiring light-shielding film 24 is provided in a plan view of one main surface of the semiconductor substrate 30. According to this configuration, the charge holding portion 32 can doubly block reflected light from the multilayer wiring layer 20 side using both the wiring light-shielding film 24 and the protrusion 27. Therefore, according to this embodiment, by suppressing stray light from entering the charge holding portion 32, crosstalk between adjacent pixels 2 is suppressed, or a decrease in resolution or color reproduction characteristics is suppressed, etc.

[0102] Note that an interlayer insulating layer 41 including an insulating material having a high light transmittance is provided on one main surface on the light-receiving surface side of the semiconductor substrate 30. For example, the interlayer insulating layer 41 may include an insulating material having a light transmittance of about 70% or more in the visible light band. Alternatively, the interlayer insulating layer 41 may include an insulating material having a refractive index smaller than that of the semiconductor substrate 30 to suppress reflection of incident light.

[0103] For example, the interlayer insulating layer 41 may include insulating materials such as silicon oxide (SiO2), silicon nitride (SiN), silicon oxynitride (SiON), hafnium oxide (HfO2), aluminum oxide (Al2O3), zirconium oxide (ZrO2), tantalum oxide (Ta2O5), titanium oxide (TiO2), lanthanum oxide (La2O3), praseodymium oxide (Pr2O3), cerium oxide (CeO2), neodymium oxide (Nd2O3), promethium oxide (Pm2O3), samarium oxide (Sm2O3), europium oxide (Eu2O3), gadolinium oxide (Gd2O3), terbium oxide (Tb2O3), dysprosium oxide (Dy2O3), holmium oxide (Ho2O3), thulium oxide (Tm2O3), ytterbium oxide (Yb2O3), lutetium oxide (Lu2O3), and yttrium oxide (Y2O3).

[0104] A sub on-chip lens 42 is also provided on the light-receiving surface side of the interlayer insulating layer 41. The sub on-chip lens 42 is provided as a convex lens that concentrates light entering the pixel 2 to effectively allow light to enter the photoelectric conversion portion 31. For example, the sub on-chip lens 42 may include a transparent organic resin such as a styrene-based resin, an acrylic resin, a styrene-acrylic copolymer-based resin, and a silicone-based resin to achieve a light transmittance of 70% or more in the visible light band. In addition, the sub on-chip lens 42 may be embedded in a planarization film 43 including an organic resin or the like.

[0105] A pixel separation structure 46 formed between pixels 2 in the interlayer insulating layer 41, the sub-chip on-lens 42, and the planarization film 43 is provided to penetrate the interlayer insulating layer 41, the sub-chip on-lens 42, and the planarization film 43. For example, the pixel separation structure 46 includes a light-shielding metal such as tungsten (W). The pixel separation structure 46 can suppress crosstalk between adjacent pixels 2 by blocking obliquely incident light between the pixels 2.

[0106] A main on-chip lens is further provided on the light-receiving surface side of the planarization film 43, and a color filter layer 44 is interposed between the main on-chip lens 45 and the planarization film 43. The main on-chip lens 45 can cooperate with the sub-chip on-lens 42 to enhance the light concentration of the incident light entering the photoelectric conversion unit 31 in the pixel 2.

[0107] For example, the color filter layer 44 can be formed by applying a resin including a red, green, or blue pigment or dye to the light-receiving surface side of the planarization film 43. For example, the color filter layer 44 can be arranged such that the corresponding colors among red, green, and blue have a Bayer array, or can be arranged such that the corresponding colors among red, green, and blue have other arrangements.

[0108] Similar to the sub-chip on-lens 42, the main on-chip lens 45 is provided as a convex lens that concentrates the incident light entering the pixel 2 to effectively allow the light to enter the photoelectric conversion unit 31. For example, the main on-chip lens 45 can include a transparent organic resin such as a styrene-based resin, an acrylic resin, a styrene-acrylic copolymer-based resin, and a siloxane-based resin to achieve a light transmittance of more than 70% in the visible light band.

[0109] In the imaging device 1 according to the present embodiment, a protruding portion 27 protruding in the in-plane direction of the semiconductor substrate 30 is provided on a contact plug 26 electrically connected to the gate electrode 25 of the transfer transistor that controls the inflow and outflow of the charge held in the charge holding unit 32. According to this configuration, the protruding portion 27 can cover an opening 24A provided in the wiring light-shielding film 24 for passing the contact plug 26. Therefore, stray light entering the charge holding unit 32 can be further suppressed.

[0110] (2.2. Structural examples of the protruding portion)

[0111] Next, specific structural examples of the protruding portion 27 provided on the contact plug 26 will be described with reference to Figure 3 and Figures 4A to 4D illustrate specific structural examples of the protruding portion 27 provided on the contact plug 26.

[0112] (First structural example)

[0113] First, a first structural example of the protruding portion 27 will be described with reference to Figure 3 illustrate the first structural example of the protruding portion 27.Figure 3 is a longitudinal cross-sectional view showing a first structural example of the protrusion 27. In Figure 3 , the downward direction when viewed from the side opposite to the figure corresponds to the direction toward the semiconductor substrate 30 side (i.e., the light-receiving surface side), and the upward direction when viewed from the side opposite to the figure corresponds to the direction toward the multilayer wiring layer 20 side.

[0114] As Figure 3 shown, the transfer transistor that controls the inflow and outflow of the charge held by the charge holding unit 32 can be set as an embedded field transistor, and this embedded field transistor includes, for example, a gate electrode 250 embedded in the semiconductor substrate 30.

[0115] The gate electrode 250 includes, for example, polysilicon or the like, and includes a flat portion 250A provided on one main surface of the semiconductor substrate 30 and a dug-in portion 250B dug into the semiconductor substrate 30. A gate insulating film 251 is provided to cover the gate electrode 250, and this gate insulating film 251 is provided at the interface between the gate electrode 250 and the semiconductor substrate 30 and contains silicon oxide or the like. In addition, conductive impurities are introduced into a predetermined region of the semiconductor substrate 30 to form a channel in the semiconductor substrate 30 as a charge transfer path from the charge holding unit 32.

[0116] A sidewall insulating film 252 is provided on the side surface of the flat portion 250A of the gate electrode 250. This sidewall insulating film 252 includes insulating materials such as silicon oxide, silicon nitride, or silicon oxynitride, and is used to highly precisely control the region of the semiconductor substrate 30 into which the conductive impurities are introduced. For example, the sidewall insulating film 252 is manufactured by forming an insulating layer including an insulating material in a manner covering the side surface of the flat portion 250A of the gate electrode 250, and then anisotropically vertically etching this insulating layer.

[0117] A first insulating layer 223 and a second insulating layer 224 are sequentially provided on the upper surface of the flat portion 250A of the gate electrode 250. Specifically, the first insulating layer 223 and the second insulating layer 224 are uniformly provided on the semiconductor substrate 30, and are formed to cover the flat portion 250A of the gate electrode 250 and the sidewall insulating film 252. The first insulating layer 223 and the second insulating layer 224 can include insulating materials such as silicon oxide, silicon nitride, or silicon oxynitride.

[0118] A wiring light-shielding film 240 is provided on the second insulating layer 224. Specifically, the wiring light-shielding film 240 includes a light-shielding metal material such as tungsten and is provided on the second insulating layer 224. In addition, an opening 240A is provided in the wiring light-shielding film 240 above the flat portion 250A of the gate electrode 250, and the contact plug electrically connected to the gate electrode 250 can pass through the opening 240A. Note that a barrier layer 241 may be provided on the upper surface of the wiring light-shielding film 240 to suppress the diffusion of the metal material forming the wiring light-shielding film 240. For example, the barrier layer 241 may include titanium, tantalum, titanium nitride, or tantalum nitride, etc.

[0119] A third insulating layer 221 is provided on the wiring light-shielding film 240. The third insulating layer 221 is uniformly provided on one main surface of the semiconductor substrate 30 and is formed to cover the upper surface of the wiring light-shielding film 240 and the inside of the opening 240A of the wiring light-shielding film 240 along the shape of the wiring light-shielding film 240. The third insulating layer 221 may include an insulating material such as silicon oxide, silicon nitride, or silicon oxynitride.

[0120] The first contact plug 270 is provided to pass through the opening formed in the wiring light-shielding film 240 and penetrate the first insulating layer 223, the second insulating layer 224, and the third insulating layer 221 to be electrically connected to the gate electrode 250. Specifically, the first contact plug 270 includes an extension portion 270B extending from the upper surface of the flat portion 250A of the gate electrode 250 in the thickness direction of the semiconductor substrate 30 to the upper surface of the third insulating layer 221 and a protruding portion 270A protruding in the in-plane direction of the semiconductor substrate 30 along the shape of the third insulating layer 221.

[0121] The protruding portion 270A is provided to cover the opening 240A formed in the wiring light-shielding film 240 and overlap with the region where the wiring light-shielding film 240 is provided in the thickness direction of the semiconductor substrate 30. For example, the protruding portion 270A may be provided to cover a region slightly larger than the opening 240A formed in the wiring light-shielding film 240 in the plan view of one main surface of the semiconductor substrate 30 when viewed from the thickness direction of the semiconductor substrate 30. The protruding portion 270A may be symmetrically or asymmetrically provided in the plane of the semiconductor substrate 30. The first contact plug 270 including the protruding portion 270A may include a light-shielding metal material such as tungsten.

[0122] In addition, a fourth insulating layer 222 is provided so as to extend over the entire surface of the semiconductor substrate 30 such that the first contact plug 270 is embedded in the fourth insulating layer 222. The fourth insulating layer 222 may include an insulating material such as silicon oxide, silicon nitride, or silicon oxynitride.

[0123] A second contact plug 260 is provided on the protrusion 270A of the first contact plug 270, and the second contact plug 260 penetrates through the fourth insulating layer 222. For example, the second contact plug 260 may be coaxially provided on the protrusion 270A with respect to the extension 270B of the first contact plug 270. The second contact plug 260 electrically connects the first contact plug 270 and the wiring layer 21. In this way, a potential is applied to the gate electrode 250 from the wiring layer 21 via the first contact plug 270 and the second contact plug 260. Note that a barrier layer 261 may be provided on the surface of the second contact plug 260 to suppress the diffusion of the metal material forming the second contact plug 260. For example, the barrier layer 261 may include titanium, tantalum, titanium nitride, tantalum nitride, or the like.

[0124] Next, a method of forming the protrusion 270A according to a first exemplary configuration will be described with reference to Figures 4A to 4D illustrate according to Figure 3 a method of forming the protrusion 270A of the first exemplary configuration shown. Figures 4A to 4D FIG. is a longitudinal cross-sectional view illustrating each step of a method of forming the protrusion 270A according to the first exemplary configuration.

[0125] First, by using a known method, such as Figure 4A shown, a gate insulating film 251 and a gate electrode 250 are formed, and then a sidewall insulating film 252, a first insulating layer 223, and a second insulating layer 224 are formed on the semiconductor substrate 30. Subsequently, a wiring light-shielding film 240 is formed on the second insulating layer 224, and then an opening 240A is formed in a region including a region where the first contact plug 270 is to be formed in a later step. In addition, a third insulating layer 221 is uniformly formed on the wiring light-shielding film 240 and the second insulating layer 224.

[0126] Subsequently, as Figure 4B shown, using dry etching, a contact opening 271 is formed inside the opening 240A of the wiring light-shielding film 240 that penetrates through the third insulating layer 221, the second insulating layer 224, and the first insulating layer 223 to expose the gate electrode 250.

[0127] Thereafter, as Figure 4C shown, a light-shielding material such as tungsten is formed on the third insulating layer 221 to fill the contact opening 271 with the light-shielding material. Subsequently, a part of the light-shielding material is removed by etching, thereby forming the first contact plug 270. For example, the light-shielding material is removed from the upper side of the third insulating layer 221 such that a part of the region where the protrusion 270A of the first contact plug 270 is formed and a part of the region where the wiring light-shielding film 240 is formed overlap each other in the thickness direction of the semiconductor substrate 30. In this way, the first contact plug 270 including the light-shielding material formed as the extension 270B inside the contact opening 271 and the light-shielding material formed as the protrusion 270A on the third insulating layer 221 is manufactured.

[0128] Thereafter, as Figure 4D shown, the fourth insulating layer 222 on the first contact plug 270 and the third insulating layer 221 is uniformly formed by chemical vapor deposition (CVD) or the like, and then the fourth insulating layer 222 is planarized by chemical mechanical polishing (CMP). Thereafter, an opening is formed through the fourth insulating layer 222 to expose the first contact plug 270 by etching or the like, and then the opening is filled with tungsten or the like to form the second contact plug 260. Subsequently, a wiring layer 21 electrically connected to the second contact plug 260 is formed.

[0129] The protrusion 270A according to the first structural example can be manufactured by the above steps. In the protrusion 270A according to the first structural example, the protrusion 270A of the first contact plug 270 is provided on the side opposite to the side where the semiconductor substrate 30 is provided with respect to the wiring light-shielding film 240 (i.e., Figure 3 the upper side in ). According to the first structural example, in the plan view observed from the thickness direction of the semiconductor substrate 30, the opening 240A formed above the gate electrode 250 in the wiring light-shielding film 240 is blocked without a gap by the protrusion 270A of the first contact plug 270. Therefore, the protrusion 270A can block the opening 240A formed in the wiring light-shielding film 240 in the thickness direction of the semiconductor substrate 30 and provide the first contact plug 270 electrically connected to the gate electrode 250. Therefore, the protrusion 270A can suppress stray light from propagating from the multilayer wiring layer 20 to the semiconductor substrate 30.

[0130] (Second Structural Example)

[0131] Next, a second structural example of the protrusion 27 will be described with reference to Figure 5 . Figure 5 is a longitudinal cross-sectional view showing a second structural example of the protrusion 27. In Figure 5 , the downward direction when viewed from the side opposite to the figure corresponds to the direction toward the semiconductor substrate 30 side (i.e., the light-receiving surface side), and the upward direction when viewed from the side opposite to the figure corresponds to the direction toward the multilayer wiring layer 20 side.

[0132] As Figure 5 shown, the difference between the second structural example and the first structural example is that the protrusion 270A of the first contact plug 270 is provided on the side where the semiconductor substrate 30 is provided with respect to the wiring light-shielding film 240 (i.e., Figure 5 the lower side in ). Note that the gate electrode 250, the gate electrode insulating film 251, the sidewall insulating film 252, the first insulating layer 223, the second insulating layer 224, and the fourth insulating layer 222 are constructed as described with reference to Figure 3 . Therefore, the same description is omitted here.

[0133] On the second insulating layer 224, a first contact plug 270 is provided corresponding to the flat portion 250A of the gate electrode 250, and the first contact plug 270 is electrically connected to the gate electrode 250. The first contact plug 270 includes an extension portion 270B provided in a manner that penetrates the first insulating layer 223 and the second insulating layer 224, and a protruding portion 270A provided on the second insulating layer 224 and formed to protrude in the in-plane direction of the semiconductor substrate 30.

[0134] The protruding portion 270A is provided in a region larger than the opening 240A. The opening 240A is provided in the wiring light-shielding film 240 and enables the second contact plug 260 to pass through the opening 240A. For example, the protruding portion 270A may be provided in a flat region corresponding to the upper surface of the flat portion 250A of the gate electrode 250. The protruding portion 270A may be provided symmetrically or asymmetrically in the plane of the semiconductor substrate 30. The first contact plug 270 including the protruding portion 270A may include a light-shielding metal material such as tungsten.

[0135] In addition, a third insulating layer 221 is provided on the second insulating layer 224 and the protruding portion 270A of the first contact plug 270. The third insulating layer 221 is uniformly provided on one main surface of the semiconductor substrate 30 and is formed to cover the gate electrode 250 including the protruding portion 270A of the first contact plug 270. The third insulating layer 221 may include an insulating material such as silicon oxide, silicon nitride, or silicon oxynitride.

[0136] A wiring light-shielding film 240 is provided on the third insulating layer 221. Specifically, a wiring light-shielding film 240 including a light-shielding metal material such as tungsten is provided on the third insulating layer 221. In addition, above the flat portion 250A of the gate electrode 250, an opening 240A for enabling a contact plug electrically connected to the gate electrode 250 to pass through is provided in the wiring light-shielding film 240. The opening 240A provided in the wiring light-shielding film 240 may be formed in a region slightly smaller than the region where the protruding portion 270A of the first contact plug 270 is provided. Note that a barrier layer 241 may be provided on the upper surface of the wiring light-shielding film 240 to suppress the diffusion of the metal material forming the wiring light-shielding film 240. For example, the barrier layer 241 may include titanium, tantalum, titanium nitride, or tantalum nitride.

[0137] A second contact plug 260 is provided on the protrusion 270A of the first contact plug 270. The second contact plug 260 passes through the opening 240A of the wiring light-shielding film 240 and penetrates the third insulating layer 221 and the fourth insulating layer 222. For example, the second contact plug 260 may be provided coaxially with the extension 270B of the first contact plug 270 on the protrusion 270A. The second contact plug 260 electrically connects the first contact plug 270 and the wiring layer 21. In this way, a potential is applied to the gate electrode 250 from the wiring layer 21 via the first contact plug 270 and the second contact plug 260. Note that a barrier layer 261 may be provided on the surface of the second contact plug 260 to suppress the diffusion of the metal material forming the second contact plug 260. For example, the barrier layer 261 may include titanium, tantalum, titanium nitride, tantalum nitride, or the like.

[0138] Next, with reference to Figures 6A to 6E the method of forming the protrusion 270A according to Figure 5 the second structural example shown will be described. Figures 6A to 6E FIG. is a longitudinal cross-sectional view showing the respective steps of the method of forming the protrusion 270A according to the second structural example.

[0139] First, by using a known method, such as Figure 6A shown, a gate electrode insulating film 251 and a gate electrode 250 are formed, and then a sidewall insulating film 252, a first insulating layer 223, and a second insulating layer 224 are formed on the semiconductor substrate 30.

[0140] Subsequently, as Figure 6B shown, using dry etching, a contact opening 271 is formed that penetrates the second insulating layer 224 and the first insulating layer 223 to expose the gate electrode 250.

[0141] Thereafter, as Figure 6C shown, a light-shielding material such as tungsten is formed on the second insulating layer 224 to fill the contact opening 271 with the light-shielding material. Subsequently, the light-shielding material in the region other than the upper surface of the gate electrode 250 is removed by etching to form the first contact plug 270. In this way, the first contact plug 270 including the light-shielding material formed as the extension 270B inside the contact opening 271 and the light-shielding material formed as the protrusion 270A on the second insulating layer 224 is manufactured.

[0142] Thereafter, as Figure 6D shown, a third insulating layer 221 is uniformly formed on the first contact plug 270 and the second insulating layer 224. Subsequently, a wiring light-shielding film 240 is formed on the third insulating layer 221, and then an opening 240A is formed in the region including the region where the second contact plug 260 to be connected to the first contact plug 270 is to be formed.

[0143] Thereafter, as Figure 6E shown, the fourth insulating layer 222 on the wiring light-shielding film 240 and the third insulating layer 221 is uniformly formed by chemical vapor deposition (CVD) or the like, and then the fourth insulating layer 222 is planarized by chemical mechanical polishing (CMP). Thereafter, an opening is formed through the third insulating layer 221 and the fourth insulating layer 222 to expose the first contact plug 270 by etching or the like, and then the opening is filled with tungsten or the like to form the second contact plug 260. Subsequently, the wiring layer 21 electrically connected to the second contact plug 260 is formed.

[0144] The protrusion 270A according to the second configuration example can be manufactured by the above steps. For the protrusion 270A according to the second configuration example, the protrusion 270A of the first contact plug 270 is provided on the side where the semiconductor substrate 30 is provided with respect to the wiring light-shielding film 240 (i.e., Figure 5 the lower side in

[0145] (2.3. Modification example)

[0146] Next, a modification example of the imaging device 1 according to the present embodiment will be described with reference to Figures 7 to 10 The technology according to the present embodiment is applicable to devices other than the imaging device 1 including the Figure 2 shown charge holding unit 32 and realizing the global shutter operation. Figures 7 to 10 are longitudinal cross-sectional views showing examples of imaging devices to which the technology according to the present embodiment is applicable.

[0147] For example, as Figure 7 shown, the technology according to the present embodiment is also applicable to an imaging device that realizes the global shutter operation by using a floating diffusion region (FD) 34 having a predetermined capacitance instead of the charge holding unit 32.

[0148] According to the Figure 7 shown imaging device, the floating diffusion region 34 is provided instead of the charge holding unit 32. Therefore, the light-shielding structure 33 and the wiring light-shielding film 24 are not provided. In addition, the pixel separation structure 46 includes a pixel insulating film 46A and a pixel defining film 46B. The pixel insulating film 46A includes an insulating material and is provided so as to extend in the thickness direction of the semiconductor substrate 30 to electrically isolate the pixels 2 from each other. The pixel defining film 46B includes light-shielding tungsten or the like and defines the range of the pixels 2.

[0149] In the imaging device configured as described above, the protruding portion 27 is provided on the contact plug 26 connected to the gate electrode 25 of the field effect transistor, and the gate electrode 25 controls the entry of charges into the floating diffusion region 34 and the exit of charges from the floating diffusion region 34. With this configuration, the protruding portion 27 can shield the floating diffusion region 34 from light that passes through the semiconductor substrate 30 and is reflected on the wiring layer 21 in the adjacent pixel 2. Therefore, even in the imaging device configured as described above, the protruding portion 27 can suppress crosstalk between adjacent pixels 2.

[0150] In addition, as Figure 8 shown, the technology according to the present embodiment is also applicable to an imaging device including a charge holding portion 32 laminated on the photoelectric conversion portion 31 in the thickness direction of the semiconductor substrate 30.

[0151] According to Figure 8 the imaging device shown, a light shielding structure 33 is provided between the charge holding portion 32 and the photoelectric conversion portion and on the side surfaces of the charge holding portion 32. In addition, the pixel separation structure 46 includes a pixel insulating film 46A and a pixel defining film 46B. The pixel insulating film 46A includes an insulating material and is provided to extend in the thickness direction of the semiconductor substrate 30 to electrically isolate the pixels 2 from each other. Further, the pixel defining film 46B including tungsten or the like having light shielding properties defines the range of the pixel 2 and prevents reflected light or the like from entering the adjacent pixel 2 in the region where the sub-chip lens 42 is provided.

[0152] In the imaging device configured as described above, the protruding portion 27 is provided on the contact plug 26 electrically connected to the gate electrode 25 of the field effect transistor, and the gate electrode 25 controls the entry of charges into the floating diffusion region 34 and the exit of charges from the floating diffusion region 34. With this configuration, the protruding portion 27 can shield the charge holding portion 32 from light that passes through the semiconductor substrate 30 and is reflected on the wiring layer 21 in the adjacent pixel 2. Therefore, even in the imaging device configured as described above, the protruding portion 27 can suppress crosstalk between adjacent pixels 2.

[0153] In addition, as Figure 9 shown, the technology according to the present embodiment is also applicable to an imaging device used as a vehicle-mounted device and including a mixture of pixels of different sizes. The imaging device including a mixture of pixels of different sizes can perform such an operation: using the pixel signals of small pixels in a bright environment and using the pixel signals of large pixels in a dark environment. Therefore, the imaging device including a mixture of pixels of different sizes can expand the detectable dynamic range of the amount of light.

[0154] According to Figure 9The imaging device shown does not provide a charge holding section 32. Accordingly, a light shielding structure 33 and a wiring light shielding film 24 are not provided. Further, the pixel separation structure 46 includes a pixel insulating film 46A and a pixel defining film 46B. The pixel insulating film 46A includes an insulating material and is provided so as to extend in the thickness direction of the semiconductor substrate 30 to electrically isolate the pixels 2 from each other. The pixel defining film 46B includes light-shielding tungsten or the like and defines the range of the pixels 2.

[0155] In the imaging device configured as described above, a protruding portion 27 is provided on a contact plug 26 that is electrically connected to a gate electrode 25 of a field effect transistor provided between the pixels 2. In an imaging device including a mixture of pixels of different sizes, the presence or absence of a field effect transistor between the pixels 2 is switched according to the arrangement of the pixels 2. In this case, the light shielding property between the pixels 2 may be reduced due to the presence of the field effect transistor between the pixels 2.

[0156] According to the technique of the present embodiment, the protruding portion 27 is provided to block light that passes through the semiconductor substrate 30 and is reflected on the wiring layer 21 in adjacent pixels 2. In this case, it is possible to suppress a reduction in the light shielding property between the pixels 2 where the field effect transistor is present. Accordingly, even in the imaging device configured as described above, the protruding portion 27 can suppress crosstalk between adjacent pixels 2.

[0157] In addition, as Figure 10 shown, the technique according to the present embodiment is also applicable to a back-illuminated imaging device.

[0158] According to Figure 10 the imaging device shown, a charge holding section 32 is not provided. Accordingly, a light shielding structure 33 and a wiring light shielding film 24 are not provided. Further, the pixel separation structure 46 includes a pixel insulating film 46A and a pixel defining film 46B. The pixel insulating film 46A includes an insulating material and is provided so as to extend in the thickness direction of the semiconductor substrate 30 to electrically isolate the pixels 2 from each other. Further, the pixel defining film 46B including tungsten or the like having light shielding properties defines the range of the pixels 2 and prevents reflected light or the like from entering adjacent pixels 2 in a region where the sub-chip lens 42 is provided.

[0159] In the imaging device configured as described above, a protruding portion 27 is provided on a contact plug 26 that is electrically connected to a gate electrode 25 of a field effect transistor provided between the pixels 2. In a back-illuminated imaging device, a multilayer wiring layer 20 is provided on the side opposite to the light receiving surface side with respect to the photoelectric conversion section 31. For example, the layout of the wiring layer 21 provided in the multilayer wiring layer 20 varies according to the arrangement direction of the pixels 2. In this case, the amount of light reflected on the wiring layer 21 of the multilayer wiring layer 20 varies according to the arrangement direction of the pixels 2 or the like. Accordingly, depending on the layout of the wiring layer 21, resolution differences or brightness differences may occur in each pixel 2.

[0160] According to the technology of the present embodiment, the protrusion 27 is provided to block light that is transmitted through the semiconductor substrate 30 and reflected on the wiring layer 21 in the adjacent pixel 2. In this case, crosstalk between adjacent pixels 2 caused by stray light can be reduced. Therefore, the protrusion 27 can suppress the resolution difference or brightness difference of each pixel 2 caused by the layout of the wiring layer 21.

[0161] <3. Second embodiment>

[0162] (3.1. Pixel structure)

[0163] Next, we will refer to Figure 11 The configuration of the pixel 2 in the image pickup device according to the second embodiment of the present disclosure is described. Figure 11 : is a plan view showing an example of the pixel 2 of the image pickup device according to the present embodiment.

[0164] like Figure 11 As shown, the pixel 2 includes a photodiode as a photoelectric conversion portion 70, which includes a second conductivity type (e.g., n-type) region in a first conductivity type (e.g., p-type) region formed in a semiconductor substrate 51. The photoelectric conversion portion 70 is capable of generating a charge amount corresponding to incident light by photoelectric conversion and accumulating the charge amount.

[0165] In addition, the pixel 2 includes a first transfer gate (gate electrode 61), a charge holding portion 71, a second transfer gate (gate electrode 62), a floating diffusion region 72, a reset transistor (gate electrode 63), an amplification transistor (gate electrode 64) and a selection transistor (gate electrode 65).

[0166] The gate electrode 61 of the first transfer gate is provided between the photoelectric conversion portion 70 on the upper portion of the charge retention portion 71 and the charge retention portion 71, and a gate electrode insulating film is interposed between the gate electrode 61 and the photoelectric conversion portion 70 and between the gate electrode 61 and the charge retention portion 71. In the first transfer gate, a transfer pulse is applied to the gate electrode 61 via a contact to transfer the charge accumulated in the photoelectric conversion portion 70 to the charge retention portion 71.

[0167] The charge holding portion 71 is provided below the gate electrode 61 of the first transfer gate, and is produced by forming a second conductivity type (e.g., n-type) region in a first conductivity type (e.g., p-type) region of the semiconductor substrate 51. The charge holding portion 71 temporarily holds the charge transferred from the photoelectric conversion portion 70 by the first transfer gate.

[0168] The gate electrode 62 of the second transfer gate is disposed between the charge holding section 71 and the floating diffusion region 72, and a gate electrode insulating film is interposed between the gate electrode 62 and the charge holding section 71 and between the gate electrode 62 and the floating diffusion region 72. In the second transfer gate, a transfer pulse is applied to the gate electrode 62 via a contact to transfer the charge held in the charge holding section 71 to the floating diffusion region 72.

[0169] The floating diffusion region 72 is a region of the second conductivity type (e.g., n-type) of the semiconductor substrate 51, and accumulates charges to convert the accumulated charges into a voltage. The contact 73 is electrically connected to the floating diffusion region 72 via a contact wiring layer 83.

[0170] The gate electrode 63 of the reset transistor is disposed adjacent to the floating diffusion region 72. In the reset transistor, the source is electrically connected to the floating diffusion region 72, the drain is electrically connected to a power supply via a contact 74, and a contact wiring layer 84 is provided between the drain and the contact 74. In the reset transistor, a reset pulse is applied to the gate electrode 63 via a contact to discharge the charge from the floating diffusion region 72 to the power supply and reset the floating diffusion region 72.

[0171] The gate electrode 64 of the amplification transistor is disposed on the side opposite to the gate electrode 63 of the reset transistor with respect to the contact wiring layer 84. In the amplification transistor, the source is electrically connected to the drain of the selection transistor, the drain is electrically connected to a power supply via a contact 74, and a contact wiring layer 84 is provided between the drain and the contact 74. In the amplification transistor, the floating diffusion region 72 is electrically connected to the gate electrode 64 via a contact.

[0172] The gate electrode 65 of the selection transistor is disposed adjacent to the gate electrode 64 of the amplification transistor. In the selection transistor, the source is electrically connected to a vertical signal line via a contact 75, and a contact wiring layer 85 is provided between the source and the contact 75, and the drain is electrically connected to the source of the amplification transistor. In the selection transistor, a selection pulse is applied to the gate electrode 64 via a contact to select the pixel 2 as a target for reading a pixel signal. In response to the conduction of the selection transistor, the amplification transistor outputs a pixel signal corresponding to the charge accumulated in the floating diffusion region 72 to the vertical signal line via the selection transistor, the contact wiring layer 85, and the contact 75.

[0173] The pixel 2 further includes a charge discharge gate (gate electrode 66) and a charge discharge section 76.

[0174] The gate electrode 66 of the charge discharge gate is provided between the photoelectric conversion unit 70 and the charge discharge unit 76, and gate electrode insulating films are interposed between the gate electrode 66 and the photoelectric conversion unit 70 and between the gate electrode 66 and the charge discharge unit 76. In the charge discharge gate, a control pulse is applied to the gate electrode 66 via a contact to transfer the charges accumulated in the photoelectric conversion unit 70 to the charge discharge unit 76.

[0175] The charge discharge unit 76 is provided in the second conductivity type (e.g., n-type) region of the semiconductor substrate 51 and is electrically connected to a power supply via a contact wiring layer 86 and a contact 77. The charge discharge gate and the charge discharge unit 76 can prevent saturation of the photoelectric conversion unit 70 and charge overflow caused by saturation during the pixel signal readout period after the exposure of the pixel 2 is completed.

[0176] Although Figure 11 not shown in the figure, a light shielding film including tungsten or the like is provided on the upper surface of the pixel 2 with an insulating layer interposed therebetween. For example, the light shielding film has openings in regions corresponding to the light receiving portions of the photoelectric conversion unit 70 and in regions where the respective contacts are formed. The light shielding film can suppress noise generated in the pixel signal due to light entering charge holding portions 71, floating diffusion regions 72, etc. other than the photoelectric conversion unit 70.

[0177] However, stray light may enter the charge accumulation region of the semiconductor substrate 51 through the openings formed in the light shielding film to allow the respective contacts to pass through. The charge accumulation region is a region provided in the pixel 2 and includes the photoelectric conversion unit 70, the charge holding unit 71, and the floating diffusion region 72 that can accumulate charges. In the charge accumulation region, new charges may be generated by photoelectric conversion caused by the entry of light within the semiconductor substrate 51. Therefore, it is important to suppress the reflected light entering the semiconductor substrate 51 in the charge accumulation region.

[0178] In the imaging device according to the present embodiment, contacts are provided in a region outside the charge accumulation region to form openings in a region outside the charge accumulation region in the light shielding film, thereby further suppressing light from entering the semiconductor substrate 51 in the charge accumulation region. Specifically, the contact 73 electrically connected to the floating diffusion region 72 is provided in a non-charge accumulation region such as an element isolation layer and is electrically connected to the floating diffusion region 72 via a contact wiring layer 83 wired in the in-plane direction of the semiconductor substrate 51. According to this configuration, the opening for providing the contact 73 formed in the shielding film is not located above the floating diffusion region 72 but above the element isolation layer. Therefore, the imaging device according to the present embodiment can suppress light from directly entering the floating diffusion region 72.

[0179] The non-charge-accumulation region here is the region in the region of pixel 2 other than the charge-accumulation region. Specifically, the non-charge-accumulation region refers to the region included in pixel 2 and corresponding to the region where an element isolation layer including an insulating material is provided, the region where an electrode or wiring is provided, and the region where a readout circuit (i.e., a circuit including an amplification transistor, a selection transistor, and a reset transistor) is provided in a stage after converting the charge in the floating diffusion region 72 into a voltage. In these non-charge-accumulation regions, it is less likely to generate noise in the pixel signal due to the entry of light. Therefore, even when there is an opening in the light-shielding film, the influence of light entry is reduced.

[0180] In addition, similar to the contact 73, contacts 74, 75, and 77 electrically connected to the semiconductor substrate 51 can be provided in non-charge-accumulation regions such as the element isolation layer, and are electrically connected to the semiconductor substrate 51 via contact wiring layers 84, 85, and 86. This configuration suppresses light from directly entering the semiconductor substrate 51 through the openings formed in the light-shielding film to allow the contacts 74, 75, and 77 to pass through. Therefore, after light enters the semiconductor substrate 51 and propagates through the semiconductor substrate 51, it is possible to further suppress light from entering the photoelectric conversion unit 70, the charge holding unit 71, or the floating diffusion region 72.

[0181] (3.2. Structural Example of Contact Wiring Layer)

[0182] Next, with reference to Figure 12 and Figure 13 a specific structural example of the contact 73 and the contact wiring layer 83 will be described, while showing a cross-section taken along the Figure 11 cutting line C-CC in Figure 12 is a longitudinal cross-sectional view showing the cross-sectional structure taken along the Figure 11 cutting line C-CC in Figure 13 is a longitudinal cross-sectional view showing a modification of the cross-sectional structure shown in Figure 12 As shown in

[0183] As Figure 12 shown, the semiconductor substrate 51 includes a floating diffusion region 72 of a second conductivity type (e.g., n-type). A first insulating layer 521 including an insulating material such as silicon oxide, silicon nitride, or silicon oxynitride is provided on the semiconductor substrate 51. A contact wiring layer 83 electrically connected to the floating diffusion region 72 via a plug 580 is provided on the first insulating layer 521.

[0184] Note that the first insulating layer 521 serves as a gate electrode insulating film for adjacent reset transistors. Therefore, the gate electrode 63 of the reset transistor is provided on the first insulating layer 521 on the CC end side.

[0185] For example, the contact wiring layer 83 extends to the upper side of the element isolation layer 513 formed by embedding silicon oxide or the like in the semiconductor substrate 51, and is electrically connected to the contact 73 on the element isolation layer 513. The contact wiring layer 83 and the plug 580 each include a conductive material. For example, the contact wiring layer 83 and the plug 580 may include polysilicon doped with a high concentration of conductive impurities, or may include a metal such as tungsten.

[0186] A light-shielding film 530 is formed on the contact wiring layer 83 and the gate electrode 63, and a second insulating layer 522 is disposed between the light-shielding film 530 and the contact wiring layer 83 and the gate electrode 63. The second insulating layer 522 includes an insulating material such as silicon oxide, silicon nitride, or silicon oxynitride. The light-shielding film 530 includes a material with light-shielding properties such as tungsten, and the light-shielding film 530 is disposed in the region of the pixel 2 other than the light-receiving portion of the photoelectric conversion unit 70 along the recesses and protrusions of the respective components provided on the semiconductor substrate 51.

[0187] The light-shielding film 530 includes an opening 530A through which the contact 73 passes. Specifically, the light-shielding film 530 includes an opening 530A above the element isolation layer 513. The contact 73 passes through the opening 530A and is electrically connected to the floating diffusion region 72 and the contact wiring layer 83. With this configuration, the light passing through the opening 530A of the light-shielding film 530 does not directly enter the floating diffusion region 72, but enters the contact wiring layer 83 and the element isolation layer 513. Therefore, according to the technology of the present embodiment, it is possible to suppress the generation of charges and noise caused by stray light entering the floating diffusion region 72.

[0188] Note that a third insulating layer 523 including an insulating material such as silicon oxide, silicon nitride, or silicon oxynitride is provided on the light-shielding film 530.

[0189] In addition, as Figure 13 shown, a silicide region 583 may be provided in the region of the contact wiring layer 83 that contacts the contact 73.

[0190] The silicide region 583 is a region where a metal-silicon compound (so-called silicide compound) such as CoSi is provided. The light absorption rate of the silicide compound in the visible light band is higher than that of polysilicon or the like. Therefore, the silicide region 583 provided in this way can reduce the transmittance of light passing through the opening 530A of the light-shielding film 530 toward the semiconductor substrate 51 side. Therefore, the silicide region 583 can further suppress stray light from entering the floating diffusion region 72, as well as the charges and noise generated by the stray light.

[0191] (3.3. Method for Forming Contact Wiring Layer)

[0192] (First Forming Method)

[0193] Next, reference will be made toFigures 14A to 14H Description Figure 12 The first forming method of the shown contact wiring layer 83. Figures 14A to 14H It is a longitudinal cross-sectional view showing each step of the first forming method of the contact wiring layer 83. The first forming method is a method of simultaneously forming the contact wiring layer 83 and the gate electrode 63.

[0194] First, as Figure 14A shown, a first insulating layer 521 is formed on a semiconductor substrate 51 provided with an element isolation layer 513 and a floating diffusion region 72. Thereafter, using a patterned resist 590, an opening 591 for generating a plug 580 is formed in the first insulating layer 521 by etching.

[0195] Subsequently, as Figure 14B shown, the resist 590 is removed, and then a silicon protective layer 585 is formed on the first insulating layer 521. As a result, the opening 591 formed in the first insulating layer 521 is filled with silicon, thereby generating the plug 580.

[0196] Thereafter, as Figure 14C shown, a part of the silicon protective layer 585 is removed by etching using a patterned resist 592 to form a silicon protective layer 585A that becomes the contact wiring layer 83 in a later step and a silicon protective layer 585B that becomes the gate electrode 63 in a later step.

[0197] Subsequently, as Figure 14D shown, using a resist 594 having openings in regions corresponding to the silicon protective layers 585A and 585B as a mask, implantation of conductive impurities is performed. In this way, conductive-type impurities are introduced into the silicon protective layers 585A and 585B so that the silicon protective layers 585A and 585B become conductive. As a result, the silicon protective layer 585B becomes the gate electrode 63.

[0198] In addition, as Figure 14E shown, using a resist 595 having openings in regions corresponding to the regions where the silicon protective layer 585A is formed as a mask, implantation of conductive impurities is performed. In this way, a higher concentration of conductive-type impurities is introduced into the silicon protective layer 585A. As a result, the silicon protective layer 585A becomes the contact wiring layer 83.

[0199] Subsequently, as Figure 14F shown, a second insulating layer 522 and a light-shielding film 530 are sequentially formed on the contact wiring layer 83 and the gate electrode 63.

[0200] Thereafter, as Figure 14GAs shown, a third insulating layer 523 is formed on the light-shielding film 530. Then, by using the patterned resist 596, the third insulating layer 523, the light-shielding film 530, and the second insulating layer 522 are etched to form an opening 597 that penetrates the third insulating layer 523, the light-shielding film 530, and the second insulating layer 522 and exposes the contact wiring layer 83.

[0201] In addition, as Figure 14H shown, the opening 597 is filled with a conductive material such as tungsten to form the contact 73.

[0202] According to the above first formation method, the contact wiring layer 83 wired from the floating diffusion region 72 on the element isolation layer 513 can be formed through fewer steps.

[0203] (Second formation method)

[0204] Subsequently, a second formation method of the contact wiring layer 83 will be described with reference to Figures 15A to 15F the description. Figure 12 shown. Figures 15A to 15F FIG. is a longitudinal cross-sectional view showing the steps of the second formation method of the contact wiring layer 83. The second formation method is a method of sequentially forming the contact wiring layer 83 and the gate electrode 63 respectively.

[0205] First, as Figure 15A shown, a first insulating layer 521 and a silicon protection layer 585 are sequentially formed on the semiconductor substrate 51 provided with the element isolation layer 513 and the floating diffusion region 72.

[0206] Thereafter, as Figure 15B shown, using the patterned resist 601, the silicon protection layer 585 in the region other than the region corresponding to the gate electrode 63 is removed by etching.

[0207] Subsequently, as Figure 15C shown, the resist 601 is removed, and then an insulating layer is formed on the semiconductor substrate 51 and the gate electrode 63. As a result, the first insulating layer 521 is formed on the semiconductor substrate 51, and the second insulating layer 522 is formed on the gate electrode 63.

[0208] Subsequently, as Figure 15D shown, using the patterned resist, an opening 603 for generating the plug 580 is formed in the first insulating layer 521 by etching.

[0209] Subsequently, as Figure 15E shown, a silicon protection layer 605 is formed on the first insulating layer 521 and the second insulating layer 522. As a result, the opening 603 formed in the first insulating layer 521 is filled with silicon to generate the plug 580.

[0210] Thereafter, as Figure 15FAs shown, using the patterned resist 606, the silicon protective layer 605 in the region other than the region corresponding to the contact wiring layer 83 is removed by etching. In this way, similar to the steps Figure 14C shown, a layer including polysilicon can be formed in the regions corresponding to the contact wiring layer 83 and the gate electrode 63.

[0211] Therefore, after removing the second insulating layer 522 provided on the gate electrode 63, by performing steps similar to those Figures 14D to 14H shown, a contact wiring layer 83 routed from the floating diffusion region 72 on the element isolation layer 513 can be formed.

[0212] According to the above-described second formation method, the contact wiring layer 83 and the gate electrode 63 can be formed respectively under process conditions suitable for the contact wiring layer 83 and process conditions suitable for the gate electrode 63.

[0213] (3.4. Modification Example)

[0214] Subsequently, a modification example of the imaging device according to the present embodiment will be described with reference to Figures 16 to 18 The technology according to the present embodiment is applicable to devices other than the imaging device including the Figure 11 pixel 2 shown. Figures 16 to 18 are longitudinal cross-sectional views respectively showing examples of imaging devices to which the technology according to the present embodiment is applicable.

[0215] For example, as shown in Figure 16 and Figure 17 , the technology according to the present embodiment is also applicable to a back-illuminated imaging device. Figure 16 and Figure 17 are longitudinal cross-sectional views schematically showing the structure of the back-illuminated imaging device.

[0216] According to the back-illuminated imaging device, as shown in Figure 16 and Figure 17 , by providing a second conductivity type (e.g., n-type) region 770A in a first conductivity type (e.g., p-type) silicon substrate 710, and providing a first conductivity type (e.g., p-type) region 770B in the region on the side where the multilayer wiring layer 723 is provided, a photoelectric conversion portion 770 serving as a photodiode is formed.

[0217] On the light receiving surface side (also referred to as the back side) of the silicon substrate 710, a pixel defining film 733, a color filter 744, and an on-chip lens 745 for defining pixels are provided, and insulating layers 741 and 743 are interposed between the silicon substrate 710 and the pixel defining film 733, the color filter 744, and the on-chip lens 745.

[0218] In addition, a transfer gate 761 for extracting the accumulated charges from the photoelectric conversion unit 770 is provided on the side of the silicon substrate 710 opposite to the light receiving surface side (also referred to as the front side). The charges extracted from the photoelectric conversion unit 770 by the transfer gate 761 are accumulated in the floating diffusion region 711 provided on the front side of the silicon substrate 710. Further, a light shielding film 730 is provided on the multilayer wiring layer 723 provided on the side of the silicon substrate 710 opposite to the light receiving surface side to block the reflected light from the wiring layer 777 and the like included in the multilayer wiring layer 723.

[0219] A contact 773 is provided on the element isolation layer 713, and the contact 773 is electrically connected to the floating diffusion region 711 via the contact wiring layer 783. Note that the charges extracted from the floating diffusion region 711 through the contact wiring layer 783 and the contact 773 are output to a reading circuit (not shown) via the wiring layer 777 and the like, and the reading circuit converts the charges into pixel signals.

[0220] As Figure 16 shown, from the viewpoints of layout or processing, there may be an opening in the light shielding film 730 here. Further, as Figure 17 shown, the light shielding film 730 may have an opening through which a contact (for example, a well contact 779) electrically connected to the silicon substrate 710 passes. According to the technique of the present embodiment, it is possible to suppress light from entering the floating diffusion region 711 from the multilayer wiring layer 723 side due to reflection on the wiring layer 777 after the light passes through the opening formed in the light shielding film 730 configured as described above.

[0221] In addition, as Figure 18 shown, the technique according to the present embodiment is also applicable to a back-illuminated imaging device that performs a global shutter operation. Figure 18 is a longitudinal cross-sectional view schematically showing the configuration of a back-illuminated imaging device that performs a global shutter operation.

[0222] According to the back-illuminated imaging device that performs a global shutter operation, as Figure 18 shown, a charge holding unit 732 including a first conductivity type region 732A and a second conductivity type region 732B is provided instead of Figure 16 and Figure 17 the floating diffusion region 711 of the back-illuminated imaging device shown. Further, a light shielding structure 734 including tungsten or the like is provided on the light receiving surface side of the charge holding unit 732, and the light shielding structure 734 is formed to cover the charge holding unit 732 to prevent light from directly entering the charge holding unit 732.

[0223] Even in such as Figure 18In the case of the back-illuminated imaging device that performs global shutter operation shown, the light that has passed through the photoelectric conversion unit 770 may further pass through the opening of the light-shielding film 730 and enter the silicon substrate 710 from the side of the multilayer wiring layer 723. According to the technology of the present embodiment, it is suppressed that the light enters the charge holding unit 732 due to reflection on the wiring layer 777 after passing through the opening of the light-shielding film 730 and entering the multilayer wiring layer 723.

[0224] <4. Application example>

[0225] Hereinafter, with reference to Figures 19 to 24 An application example of the imaging device according to the first or second embodiment of the present disclosure will be described.

[0226] (Application of imaging system)

[0227] First, with reference to Figure 19 and Figure 20 An application example of applying the imaging device according to the first or second embodiment of the present disclosure to an imaging system will be described. Figure 19 is a block diagram showing an example of the schematic configuration of an imaging system 900 including an imaging device 1 according to the first or second embodiment of the present disclosure. Figure 20 Shows an example of a flowchart of the imaging operation performed by the imaging system 900.

[0228] For example, as Figure 19 shown, the imaging system 900 is an electronic device such as a digital camera, a video camera, and other imaging devices, as well as a smartphone, a tablet terminal, and other portable terminal devices.

[0229] For example, the imaging system 900 includes a lens group 941, a shutter 942, an imaging device 1 according to the first or second embodiment of the present disclosure, a DSP circuit 943, a frame memory 944, a display unit 945, a storage unit 946, an operation unit 947, and a power supply unit 948. In the imaging system 900, the imaging device 1, the DSP circuit 943, the frame memory 944, the display unit 945, the storage unit 946, the operation unit 947, and the power supply unit 948 are interconnected via a bus 949.

[0230] The imaging device 1 outputs image data corresponding to incident light that has passed through the lens unit 941 and the shutter 942. The DSP circuit 943 is a signal processing circuit and processes the signal (i.e., image data) output from the imaging device 1. The frame memory 944 temporarily holds the image data processed by the DSP circuit 943 in units of frames. The display unit 945 is a panel-type display device such as a liquid crystal panel and an organic electroluminescent (EL) panel, for example, and the display unit 945 displays a moving image or a still image captured by the imaging device 1. The storage unit 946 includes recording media such as a semiconductor memory and a hard disk, and records image data representing a moving image or a still image captured by the imaging device 1. The operation unit 947 outputs operation commands related to various functions of the imaging system 900 based on user operations. The power supply unit 948 is various types of power supplies for supplying an operation power supply to the imaging device 1, the DSP circuit 943, the frame memory 944, the display unit 945, the storage unit 946, and the operation unit 947.

[0231] Next, the imaging process performed by the imaging system 900 will be described.

[0232] As Figure 20 shown, the user operates the operation unit 947 to command the start of imaging (S101). In response to this operation, the operation unit 947 sends an imaging command to the imaging device 1 (S102). When the imaging command is received, the imaging device 1 performs imaging using a predetermined imaging method (S103).

[0233] Thereafter, the imaging device 1 outputs the acquired image data to the DSP circuit 943. The DSP circuit 943 performs predetermined signal processing (e.g., noise reduction processing) on the image data output from the imaging device 1 (S104). The DSP circuit 943 causes the frame memory 944 to hold the image data that has undergone the predetermined signal processing. Thereafter, the frame memory 944 stores the image data in the storage unit 946 (S105). The imaging system 900 performs imaging in this way.

[0234] According to this application example, the imaging device 1 of the first or second embodiment of the present disclosure is applicable to the imaging system 900. According to the technology of the present disclosure, it is possible to further suppress noise caused by reflected light in the imaging device 1 or crosstalk between adjacent pixels 2. Therefore, according to the technology of the present disclosure, the imaging system 900 can capture higher-quality images.

[0235] (Application to a moving body control system)

[0236] The technology according to the present disclosure (this technology) is applicable to various products. For example, the technology according to the present disclosure can be implemented as a device installed on any of the following types of moving bodies, such as: automobiles, electric vehicles, hybrid vehicles, motorcycles, bicycles, personal mobility devices, airplanes, drones, ships, and robots.

[0237] Figure 21 FIG. is a block diagram showing a schematic configuration example of a vehicle control system as an example of a moving body control system to which the technology according to the present disclosure is applicable.

[0238] The vehicle control system 12000 includes a plurality of electronic control units connected to each other via a communication network 12001. Figure 21 In the example shown, the vehicle control system 12000 includes: a drive system control unit 12010, a body system control unit 12020, an outside vehicle information detection unit 12030, an inside vehicle information detection unit 12040, and an integrated control unit 12050. In addition, as a functional configuration of the integrated control unit 12050, a microcomputer 12051, an audio-visual output unit 12052, and an in-vehicle network interface (I / F) 12053 are shown in the figure.

[0239] The drive system control unit 12010 controls the operation of devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 12010 serves as a control device for the following devices: an internal combustion engine for generating the driving force of the vehicle, a drive motor, and other driving force generators; a driving force transmission mechanism for transmitting the driving force to the wheels; a steering mechanism for controlling the steering angle of the vehicle; and a braking device for generating the braking force of the vehicle.

[0240] The body system control unit 12020 controls the operation of various devices installed on the vehicle body according to various programs. For example, the body system control unit 12020 serves as a control device for a keyless entry system, a smart key system, an electric window device, or various lights such as headlights, taillights, brake lights, turn signals, and fog lights. In this case, radio waves or signals from a portable device replacing the key can be input to the body system control unit 12020. The body system control unit 12020 receives the input of these radio waves or signals and controls the door lock device, electric window device, and lights of the vehicle.

[0241] The vehicle exterior information detection unit 12030 detects exterior information outside the vehicle with the vehicle control system 12000. For example, the vehicle exterior information detection unit 12030 is connected to the imaging unit 12031. The vehicle exterior information detection unit 12030 causes the imaging unit 12031 to capture an image of the vehicle exterior and receives the captured image. Based on the received image, the vehicle exterior information detection unit 12030 can perform detection processing or distance detection processing on objects such as pedestrians, vehicles, obstacles, signs, and letters on the road surface.

[0242] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of received light. The imaging unit 12031 can output the electrical signal as an image or can output the electrical signal as ranging information. In addition, the light received by the imaging unit 12031 can be visible light or non-visible light such as infrared light.

[0243] The vehicle interior information detection unit 12040 detects vehicle interior information inside the vehicle. For example, the vehicle interior information detection unit 12040 is connected to a driver state detection unit 12041 for detecting the driver's state. For example, the driver state detection unit 12041 includes a camera for imaging the driver. In this case, based on the detection information input from the driver state detection unit 12041, the vehicle interior information detection unit 12040 can calculate the driver's fatigue level or concentration level, or can determine whether the driver is dozing off.

[0244] Based on the vehicle exterior or interior information acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, the microcomputer 12051 can calculate control target values for the driving force generation device, the steering mechanism, or the braking device, and can output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control for implementing functions of an advanced driver assistance system (ADAS), including: collision avoidance or impact mitigation of the vehicle, tracking based on the inter-vehicle distance, speed-holding driving, vehicle collision warning, and lane departure warning of the vehicle, etc.

[0245] In addition, for example, the microcomputer 12051 can control the driving force generation device, the steering mechanism, or the braking device, etc., based on the information related to the vehicle surroundings acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, so as to perform cooperative control for implementing autonomous driving that realizes autonomous driving without the driver's operation.

[0246] In addition, based on the external information related to the vehicle exterior obtained by the vehicle exterior information detection unit 12030, the microcomputer 12051 can output a control command to the vehicle body system control unit 12020. For example, the microcomputer 12051 can control the headlights according to the positions of the vehicle ahead or oncoming vehicle detected by the vehicle exterior information detection unit 12030, thereby performing cooperative control for anti-glare, such as switching the high beam to the low beam.

[0247] The sound / image output unit 12052 sends at least one of a sound output signal or an image output signal to an output device that can provide visual or auditory information notification to passengers in the vehicle or to the vehicle exterior. As an example of the output device, Figure 21 the audio speaker 12061, the display unit 12062, and the instrument panel 12063 are shown. For example, the display unit 12062 may include at least one of an in-vehicle display or a head-up display.

[0248] Figure 22 is a diagram showing an example of the installation position of the imaging unit 12031.

[0249] In Figure 22 it, as the imaging unit 12031, the vehicle 12100 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0250] For example, the imaging units 12101, 12102, 12103, 12104, and 12105 are provided at positions such as the front nose of the vehicle 12100, the rearview mirror, the rear bumper, the rear door, and the upper part of the windshield inside the vehicle compartment. The imaging unit 12101 provided at the front nose and the imaging unit 12105 provided at the upper part of the windshield inside the vehicle compartment both mainly acquire images in front of the vehicle 12100. The imaging units 12102 and 12103 provided at the rearview mirror both mainly acquire images on the side of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or the rear door mainly acquires images behind the vehicle 12100. The front images acquired by the imaging units 12101 and 12105 are mainly used to detect the vehicle ahead or pedestrians, obstacles, traffic lights, traffic signs, or lanes, etc.

[0251] Note that Figure 22An example of the imaging ranges of imaging units 12101 to 12104 is shown. Imaging range 12111 represents the imaging range of imaging unit 12101 provided at the front nose, imaging ranges 12112 and 12113 respectively represent the imaging ranges of imaging units 12102 and 12103 provided at the rearview mirror, and imaging range 12114 represents the imaging range of imaging unit 12104 provided at the rear bumper or the rear door. For example, by superimposing the image data acquired by imaging units 12101 to 12104, an aerial view image of vehicle 12100 when viewed from above is obtained.

[0252] At least one of imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of imaging units 12101 to 12104 may be a stereo camera including a plurality of imaging elements, or may be an imaging element having pixels for phase difference detection.

[0253] For example, microcomputer 12051 can obtain the distance to each three-dimensional object within imaging ranges 12111 to 12114 and the change in the distance over time (relative speed with respect to vehicle 12100) based on the distance information obtained from imaging units 12101 to 12104, and thus extract a three-dimensional object that is closest to vehicle 12100 on the driving road and traveling in substantially the same direction as vehicle 12100 at a predetermined speed (e.g., greater than or equal to 0 km / h) as the preceding vehicle. In addition, microcomputer 12051 can preset the inter-vehicle distance to be maintained between the vehicle and the preceding vehicle, and can perform automatic braking control (including follow-stop control) and automatic acceleration control (including follow-start control), etc. In this way, cooperative control for the purpose of achieving autonomous driving such as autonomous driving without driver operation can be realized.

[0254] For example, based on the distance information obtained from imaging units 12101 to 12104, microcomputer 12051 classifies three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, and other three-dimensional objects such as utility poles, extracts the classified data, and uses this data to automatically avoid obstacles. For example, microcomputer 12051 classifies obstacles around vehicle 12100 into obstacles visible to the driver of vehicle 12100 and obstacles difficult for the driver to visually recognize. Then, microcomputer 12051 determines a collision risk indicating the degree of risk of collision with each obstacle, and in a situation where a collision may occur, when the collision risk is equal to or higher than a set value, microcomputer 12051 outputs a warning to the driver through audio speaker 12061 or display unit 12062, or performs forced deceleration or avoidance steering using drive system control unit 12010, thereby realizing assisted driving to avoid collisions.

[0255] At least one of the imaging units 12101 to 12104 may be an infrared camera for detecting infrared rays. For example, the microcomputer 12051 can identify a pedestrian by determining whether there is a pedestrian in the captured images of the imaging units 12101 to 12104. For example, the following process is used for such pedestrian identification: extracting feature points in the captured images of the imaging units 12101 to 12104 that are infrared cameras; and determining whether the object is a pedestrian by performing pattern matching processing on a series of feature points representing the contour of the object. When the microcomputer 12051 determines that there is a pedestrian in the captured images of the imaging units 12101 to 12104 and identifies the pedestrian, the audio-visual output unit 12052 controls the display unit 12062 to superimpose and display a rectangular contour line for emphasis on the identified pedestrian. In addition, the audio-visual output unit 12052 may also control the display unit 12062 to display an icon or the like for representing the pedestrian at a desired position.

[0256] Examples of the mobile body control system to which the technology according to the present disclosure is applicable have been described above. The technology according to the present disclosure is applicable to the imaging unit 12031 included in the above configuration. According to the technology of the present disclosure, higher-quality images can be captured. Therefore, high-precision control of the captured images can be achieved through the mobile body control system.

[0257] (Application of Endoscopic Surgery System)

[0258] Figure 23 It is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology (this technology) according to the present disclosure is applicable.

[0259] Figure 23 It shows a state in which a surgeon (doctor) 11131 uses an endoscopic surgery system 11000 to perform surgery on a patient 11132 on a hospital bed 11133. As shown in the figure, the endoscopic surgery system 11000 includes an endoscope 11100, other surgical tools 11110 such as a pneumoperitoneum tube 11111 and an energy treatment tool 11112, a support arm device 11120 for supporting the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are installed.

[0260] The endoscope 11100 includes: a lens barrel 11101, a region having a predetermined length starting from the distal end of the lens barrel 11101 is inserted into the body cavity of a patient 11132; and a camera 11102, the camera 11102 is connected to the proximal end of the lens barrel 11101. Although the figure shows the endoscope 11100 which is a so-called rigid endoscope configured with a rigid lens barrel 11101, the endoscope 11100 can also be configured as a so-called flexible endoscope with a flexible lens barrel.

[0261] An opening is provided at the distal end of the lens barrel 11101, and an objective lens is installed in the opening. A light source device 11203 is connected to the endoscope 11100. The light generated by the light source device 11203 is guided to the distal end of the lens barrel through an optical waveguide extending in the lens barrel 11101, and the light irradiates an observation target in the body cavity of the patient 11132 via the objective lens. Note that the endoscope 11100 can be a forward-viewing endoscope, a slant-viewing endoscope, or a side-viewing endoscope.

[0262] An optical system and an imaging element are provided in the camera 11102. The reflected light (observation light) from the observation target is converged onto the imaging element through the optical system. The observation light is photoelectrically converted by the imaging element, and an electrical signal corresponding to the observation light, that is, an image signal corresponding to the observation image, is generated. This image signal is sent as raw data to a camera control unit (CCU) 11201.

[0263] The CCU 11201 includes a central processing unit (CPU) and a graphics processing unit (GPU), etc., and the CCU 11201 controls the operations of the endoscope 11100 and the display device 11202 as a whole. In addition, the CCU 11201 receives the image signal from the camera 11102, and performs various image processing operations such as imaging processing (demosaicing processing) on the image signal for displaying an image based on the image signal.

[0264] Under the control of the CCU 11201, the display device 11202 displays an image based on the image signal that has been subjected to image processing by the CCU 11201.

[0265] For example, the light source device 11203 includes a light source such as a light emitting diode (LED), and provides irradiation light to the endoscope 11100 when imaging a surgical site or the like.

[0266] The input device 11204 is the input interface of the endoscopic surgery system 11000. A user can input various information and instructions into the endoscopic surgery system 11000 through the input device 11204. For example, the user inputs instructions for changing the imaging conditions (type of illumination light, magnification, focal length, etc.) of the endoscope 11100, and the like.

[0267] The treatment tool control device 11205 controls the drive of the energy treatment tool 11112 for tissue cauterization, cutting, or blood vessel closure, etc. The pneumoperitoneum device 11206 delivers gas into the body cavity of the patient 11132 through the pneumoperitoneum tube 11111 to expand the body cavity, thereby ensuring the viewing field of the endoscope 11100 and ensuring the working space for the surgeon. 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 forms such as text, image, or chart.

[0268] Note that, for example, the light source device 11203 that provides illumination light to the endoscope 11100 during imaging of the surgical site may include an LED, a laser light source, or a white light source including a combination of an LED and a laser light source. In the case of using a white light source including a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision. Therefore, the white balance of the captured image can be adjusted by the light source device 11203. In addition, in this case, by irradiating the observation object with laser beams from each of the RGB laser light sources in a time-division manner and controlling the drive of the imaging element of the camera 11102 in synchronization with the irradiation timing, it is also possible to capture images corresponding to R, G, and B respectively in a time-division manner. According to this method, a color image can be obtained without providing a color filter on the imaging element.

[0269] In addition, the drive of the light source device 11203 can be controlled in such a way that the intensity of the output light is changed at a predetermined time interval. By acquiring images in a time-division manner while controlling the drive of the imaging element of the camera 11102 in synchronization with the timing of the light intensity change and then synthesizing the acquired images, a high-dynamic range image that does not include so-called black shadows and overexposure can be formed.

[0270] In addition, the light source device 11203 can be configured to provide light in a predetermined wavelength band corresponding to special light observation. For example, special light observation is achieved by so-called narrow-band imaging, which utilizes the wavelength dependence of light absorption in human tissues and irradiates light in a band narrower than that of the illumination light (i.e., white light) during normal observation to image predetermined tissues such as blood vessels in the mucosal surface layer with high contrast. Alternatively, special light observation can be achieved by fluorescence observation, which uses fluorescence generated by irradiating excitation light to obtain an image. For example, fluorescence observation can be performed by irradiating human tissues with excitation light and observing the fluorescence from the human tissues (autofluorescence observation), or by locally injecting a reagent such as indocyanine green (ICG) into human tissues and irradiating the human tissues with excitation light corresponding to the fluorescence wavelength of the reagent to obtain a fluorescence image. The light source device 11203 can be configured to provide narrow-band light and / or excitation light corresponding to such special light observation.

[0271] Figure 24 is a block diagram showing Figure 23 an example of the functional configuration of the illustrated camera 11102 and CCU 11201.

[0272] The camera 11102 includes a lens unit 11401, an imaging unit 11402, a driving unit 11403, a communication unit 11404, and a camera control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera 11102 and the CCU 11201 are communicably connected to each other via a transmission cable 11400.

[0273] The lens unit 11401 is an optical system provided at the connection portion with the lens barrel 11101. Observation light obtained from the distal end of the lens barrel 11101 is guided to the camera 11102 and enters the lens unit 11401. The lens unit 11401 includes a combination of a plurality of lenses (including a zoom lens and a focusing lens).

[0274] The imaging unit 11402 includes an imaging element. The imaging unit 11402 may include one imaging element (so-called single-board type) or multiple imaging elements (so-called multi-board type). For example, in the case where the imaging unit 11402 is of the multi-board type, image signals corresponding to R, G, and B can be generated by respective imaging elements, and these image signals can be synthesized to obtain a color image. Alternatively, the imaging unit 11402 may further include a pair of imaging elements for respectively acquiring a right-eye image signal and a left-eye image signal corresponding to three-dimensional (3D) display. By performing 3D display, the surgeon 11131 can more precisely identify the depth of the living tissue in the surgical site. Note that in the case where the imaging unit 11402 is of the multi-board type, a system with multiple lens units 11401 can be provided corresponding to respective imaging elements.

[0275] In addition, the imaging unit 11402 is not necessarily provided on the camera 11102. For example, the imaging unit 11402 can be provided immediately behind the objective lens within the lens barrel 11101.

[0276] The drive unit 11403 includes an actuator, and under the control of the camera control unit 11405, the drive unit 11403 moves the zoom lens and the focus lens of the lens unit 11401 along the optical axis by a predetermined distance. In this way, the magnification and focus of the image captured by the imaging unit 11402 can be appropriately adjusted.

[0277] The communication unit 11404 includes a communication device for sending various information to the CCU 11201 and receiving various information from the CCU 11201. The communication unit 11404 sends the image signal obtained from the imaging unit 11402 as raw data to the CCU 11201 via the transmission cable 11400.

[0278] In addition, the communication unit 11404 receives a control signal for controlling the drive of the camera 11102 from the CCU 11201 and provides the control signal to the camera control unit 11405. For example, the control signal includes information related to imaging conditions, that is, information specifying the frame rate of the captured image, information specifying the exposure value during imaging, and / or information specifying the magnification and focus of the captured image.

[0279] Note that the above imaging conditions such as frame rate, exposure value, magnification, and focus can be appropriately specified by the user, or can 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 has so-called auto exposure (AE), autofocus (AF), and auto white balance (AWB) functions.

[0280] The camera control unit 11405 controls the driving of the camera 11102 based on the control signal received from the CCU 11201 via the communication unit 11404.

[0281] The communication unit 11411 includes a communication device for sending various information to the camera 11102 and receiving various information from the camera 11102. The communication unit 11411 receives the image signal transmitted from the camera 11102 via the transmission cable 11400.

[0282] In addition, the communication unit 11411 sends the control signal for controlling the driving of the camera 11102 to the camera 11102. The image signal and the control signal can be transmitted via electrical communication, optical communication, etc.

[0283] The image processing unit 11412 performs various image processing operations on the image signal, which is raw data, transmitted from the camera 11102.

[0284] The control unit 11413 executes various controls related to photographing a surgical site or the like through the endoscope 11100 and displaying the image obtained by photographing the surgical site or the like. For example, the control unit 11413 generates a control signal for controlling the driving of the camera 11102.

[0285] In addition, based on the image signal that has been subjected to image processing by the image processing unit 11412, the control unit 11413 causes the display device 11202 to display the photographed image showing the surgical site or the like. At this time, the control unit 11413 can use various image recognition techniques to recognize various objects in the photographed image. For example, the control unit 11413 can recognize surgical tools such as forceps, specific living body parts, bleeding, and mist when using the energy treatment tool 11112 by detecting the shape or color of the edges of the objects included in the photographed image. During the display of the photographed image on the display device 11202, the control unit 11413 can superimpose various surgical assistance information on the image of the surgical site using the recognition result. By superimposing the surgical assistance information and presenting the superimposed display to the surgeon 11131, the burden on the surgeon 11131 can be reduced, and the surgeon 11131 can ensure the progress of the surgery.

[0286] The transmission cable 11400 connecting the camera 11102 and the CCU 11201 is an electrical signal cable corresponding to electrical signal communication, an optical fiber corresponding to optical communication, or a composite cable of these cables.

[0287] Although the examples in the figures here show wired communication using the transmission cable 11400, communication between the camera 11102 and the CCU 11201 can also be performed wirelessly.

[0288] Above, an example of an endoscopic surgical system to which the technology according to the present disclosure is applicable has been described. The technology according to the present disclosure is applicable to the imaging unit 11402 provided on the camera 11102 of the endoscope 11100 in the above configuration. According to the technology of the present disclosure, the image quality of the image captured by the imaging unit 11402 can be further improved. Therefore, the visibility and operability of the user using the endoscopic surgical system can be improved.

[0289] Here, the technology according to the present disclosure has been described in a manner presenting the first and second embodiments and their modifications. However, the technology according to the present disclosure is not limited to the above embodiments and the like, but includes various modifications.

[0290] In addition, the above first and second embodiments and their modifications can be combined with each other.

[0291] In addition, all the configurations and operations described in each embodiment are not essential for the configurations and operations of the present disclosure. For example, it should be understood that the components included in the components of each embodiment and not described in the independent claims defining the highest concept of the present disclosure are optional components.

[0292] The terms used throughout this specification and the appended claims should be construed as "non-limiting" terms. For example, the terms "comprising" or "being included" should be construed as "not limited to what is described as being included". The term "comprising" should be construed as "not limited to what is described as being included".

[0293] The terms used in this specification are terms used only for convenience of description and include terms that do not limit the configuration and operation. For example, terms such as "right", "left", "up", and "down" only indicate directions in the reference drawings. Additionally, the terms "inside" and "outside" indicate the direction towards the center of the element of interest and the direction away from the center of the element of interest, respectively. Terms similar to these terms and terms used for similar purposes are equally applicable.

[0294] Note that the technology according to the present disclosure can have the following configuration. According to the technology of the present disclosure having the following configuration, it is possible to further suppress reflected light inside the imaging device from entering the photoelectric conversion unit, charge holding unit, floating diffusion unit, etc. Therefore, the imaging device to which the technology according to the present disclosure is applicable can further suppress the generation of noise in the pixel signal. The advantages provided by the technology according to the present disclosure are not limited to the advantages described herein, but can be any advantages described in the present disclosure.

[0295] (1) An imaging device, comprising:

[0296] A semiconductor substrate including a photoelectric conversion unit configured to perform photoelectric conversion on incident light and / or a charge holding unit configured to hold charges photoelectrically converted by the photoelectric conversion unit;

[0297] A field effect transistor disposed on the photoelectric conversion unit or disposed on the semiconductor substrate near the charge holding unit;

[0298] A contact plug extending from a gate electrode of the field effect transistor in a direction perpendicular to a main surface of the semiconductor substrate; and

[0299] A protruding portion extending from the contact plug in a direction in the plane of the main surface of the semiconductor substrate.

[0300] (2) The imaging device according to (1) above, further comprising:

[0301] A light-shielding film disposed on a main surface of the semiconductor substrate on a side opposite to the surface where incident light enters the semiconductor substrate, wherein the light-shielding film includes an opening corresponding to the contact plug.

[0302] (3) The imaging device according to (2) above, wherein the protruding portion is disposed to cover the opening provided in the light-shielding film.

[0303] (4) The imaging device according to (3) above, wherein, in a plan view of the main surface of the semiconductor substrate, a part of the region where the protruding portion is formed overlaps with the region where the light-shielding film is formed.

[0304] (5) The imaging device according to any one of (2) to (4) above, wherein the protruding portion is disposed above or below the light-shielding film.

[0305] (6) The imaging device according to any one of (1) to (5) above, wherein the field effect transistor is a field effect transistor that controls charge transfer from the photoelectric conversion unit or the charge holding unit.

[0306] (7) The imaging device according to any one of (1) to (5) above,

[0307] wherein a plurality of pixels each including the photoelectric conversion unit are arranged on the semiconductor substrate, and

[0308] the field effect transistor is a field effect transistor disposed between pixels isolated from each other. (8) An imaging device, comprising:

[0309] A semiconductor substrate including a photoelectric conversion portion configured to perform photoelectric conversion on incident light, a charge holding portion configured to accumulate charges photoelectrically converted by the photoelectric conversion portion, and a read circuit configured to read the charges;

[0310] A light-shielding layer provided on one main surface of the semiconductor substrate;

[0311] A contact passing through the light-shielding layer and extending in a direction perpendicular to the one main surface of the semiconductor substrate; and

[0312] A contact wiring layer electrically connecting the contact to a source or a drain of a field effect transistor provided on the semiconductor substrate,

[0313] wherein the one main surface of the semiconductor substrate includes a charge accumulation region and a non-charge accumulation region, the charge accumulation region includes at least the photoelectric conversion portion and the charge holding portion, the non-charge accumulation region includes the read circuit, and

[0314] the contact wiring layer extends to the non-charge accumulation region and is electrically connected to the contact in the non-charge accumulation region.

[0315] (9) The imaging device according to (8) above,

[0316] wherein an element isolation layer is further provided on the semiconductor substrate in the non-charge accumulation region, and

[0317] the contact wiring layer is electrically connected to the contact on the element isolation layer.

[0318] (10) The imaging device according to (8) or (9) above, wherein the light-shielding layer is provided in a region of the one main surface of the semiconductor substrate other than a region corresponding to the photoelectric conversion portion.

[0319] (11) The imaging device according to any one of (8) to (10) above, wherein the contact wiring layer includes polysilicon containing a conductive impurity.

[0320] (12) The imaging device according to (11) above, wherein a silicide layer is further provided at a connection portion of the contact wiring layer with the contact.

[0321] (13) The imaging device according to any one of (8) to (12) above, wherein the incident light enters the photoelectric conversion portion from a side where the light-shielding layer is provided.

[0322] (14) The imaging device according to any one of (8) to (12) above, wherein the incident light enters the photoelectric conversion unit from the side opposite to the side where the light shielding layer is provided.

[0323] Those skilled in the art should understand that various modifications, combinations, sub - combinations and changes can be made according to design requirements and other factors, as long as these modifications, combinations, sub - combinations and changes are within the scope of the appended claims or their equivalents.

[0324] [List of reference numerals]

[0325] 1 Imaging device

[0326] 2 Pixel

[0327] 3 Pixel array unit

[0328] 4 Vertical drive circuit

[0329] 5 Column signal processing circuit

[0330] 6 Horizontal drive circuit

[0331] 7 Output circuit

[0332] 8 Control circuit

[0333] 10 Pixel drive wiring

[0334] 11 Horizontal signal line

[0335] 20 Multilayer wiring layer

[0336] 21 Wiring layer

[0337] 22 Inter - layer insulating layer

[0338] 23, 26 Contact plug

[0339] 24 Wiring light - shielding film

[0340] 24A Opening

[0341] 25 Gate electrode

[0342] 27 Protrusion

[0343] 30 Semiconductor substrate

[0344] 31 Photoelectric conversion unit

[0345] 32 Charge holding unit

[0346] 33 Light - shielding structure

[0347] 33A First light - shielding film

[0348] 33B Second Light-Shielding Film

[0349] 33C Third Light-Shielding Film

[0350] 34 Floating Diffusion Region

[0351] 41 Interlayer Insulating Layer

[0352] 42 Sub-Chip Upper Lens

[0353] 43 Planarization Film

[0354] 44 Color Filter Layer

[0355] 45 Main-Chip Upper Lens

[0356] 46 Pixel Separation Structure

[0357] 46A Pixel Insulating Film

[0358] 46B Pixel Definition Film

[0359] 51 Semiconductor Substrate

[0360] 61,62,63,64,65,66 Gate Electrodes

[0361] 70 Photoelectric Conversion Section

[0362] 71 Charge Retention Section

[0363] 72 Floating Diffusion Region

[0364] 73,74,75,77 Contacts

[0365] 76 Charge Discharge Section

[0366] 83,84,85,86 Contact Wiring Layers

Claims

1. An imaging device, comprising: A semiconductor substrate including a photoelectric conversion portion and / or a charge holding portion, the photoelectric conversion portion being configured to perform photoelectric conversion on incident light, and the charge holding portion being configured to hold charges photoelectrically converted by the photoelectric conversion portion; A multilayer wiring layer provided on a surface of the semiconductor substrate opposite to a surface on which incident light enters; A field-effect transistor provided on the photoelectric conversion portion or provided on the semiconductor substrate near the charge holding portion; A contact plug including an extending portion and a protruding portion, the extending portion extending from a gate electrode of the field-effect transistor in a direction perpendicular to a main surface of the semiconductor substrate, and the protruding portion extending from the contact plug in a in-plane direction of the main surface of the semiconductor substrate; wherein the field-effect transistor is electrically connected to the multilayer wiring layer via the contact plug.

2. The imaging device according to claim 1, further comprising: A light-shielding film provided on a main surface of the semiconductor substrate on a side opposite to a surface of the semiconductor substrate on which incident light enters, wherein the light-shielding film includes an opening corresponding to the contact plug.

3. The imaging device according to claim 2, wherein, The protruding portion is provided to cover the opening provided in the light-shielding film.

4. The imaging device according to claim 3, wherein, In a plan view of the main surface of the semiconductor substrate, a part of a region where the protruding portion is formed overlaps with a region where the light-shielding film is formed.

5. The imaging device according to claim 2, wherein, The protruding portion is provided above or below the light-shielding film.

6. The imaging device according to any one of claims 1 to 5, wherein, The field-effect transistor is a field-effect transistor that controls charge transfer from the photoelectric conversion portion or the charge holding portion.

7. The imaging device according to any one of claims 1 to 5, Among them, A plurality of pixels each including the photoelectric conversion portion are arranged on the semiconductor substrate, and The field-effect transistor is a field-effect transistor provided between pixels isolated from each other.

8. An imaging device, comprising: A semiconductor substrate including a photoelectric conversion portion configured to perform photoelectric conversion on incident light, a charge holding portion configured to accumulate charges photoelectrically converted by the photoelectric conversion portion, and a read circuit configured to read the charges; A light-shielding layer provided on a main surface of the semiconductor substrate; A contact penetrating the light-shielding layer and extending in a direction perpendicular to the main surface of the semiconductor substrate; and A contact wiring layer electrically connecting the contact to a source or a drain of a field-effect transistor provided on the semiconductor substrate, wherein the main surface of the semiconductor substrate includes a charge accumulation region and a non-charge accumulation region, the charge accumulation region includes at least the photoelectric conversion portion and the charge holding portion, the non-charge accumulation region includes the read circuit, and The contact wiring layer extends to the non-charge accumulation region and is electrically connected to the contact in the non-charge accumulation region.

9. The imaging device according to claim 8, Among them, In the non-charge-accumulating region, an element isolation layer is further provided on the semiconductor substrate, and the contact wiring layer is electrically connected to the contacts on the element isolation layer.

10. The imaging device according to claim 8 or 9, wherein, The light-shielding layer is provided in a region of the one main surface of the semiconductor substrate other than the region corresponding to the photoelectric conversion unit.

11. The imaging device according to claim 8 or 9, wherein, The contact wiring layer includes polysilicon containing a conductive impurity.

12. The imaging device according to claim 11, wherein, A silicide layer is further provided at a connection portion of the contact wiring layer with the contacts.

13. The imaging device according to claim 8 or 9, wherein, The incident light enters the photoelectric conversion unit from the side where the light-shielding layer is provided.

14. The imaging device according to claim 8 or 9, wherein, The incident light enters the photoelectric conversion unit from the side opposite to the side where the light-shielding layer is provided.

Images