Light detection device, semiconductor device, and method for manufacturing light detection device

Abstract

Provided are a light detection device, a semiconductor device, and a method for manufacturing a light detection device that make it possible to minimize any decrease in reliability. This light detection device comprises: a semiconductor substrate; an organic insulating film that is made of a translucent organic material and is provided to the first-surface side of the semiconductor substrate; a groove part that is provided to the organic insulating film and the semiconductor substrate, the groove part having the semiconductor substrate as the bottom surface thereof; a first inorganic insulating film that is made of a translucent inorganic material, is provided to the first-surface side of the semiconductor substrate, covers the organic insulating film, and plugs the groove part; and a second inorganic insulating film that is made of a translucent organic material and is provided on the first inorganic insulating film. The semiconductor substrate has, on the first-surface side thereof, a first region positioned on one side of the groove and a second region positioned on the other side of the groove. The surface of the first inorganic insulating film is flat at least above the groove part.

Description

Photodetector, semiconductor device, and method for manufacturing a photodetector

[0001] The present disclosure relates to a photodetector, a semiconductor device, and a method for manufacturing a photodetector.

[0002] 2. Description of the Related Art In recent years, imaging devices in which a plurality of charge coupled devices (CCDs) or complementary metal-oxide semiconductor (CMOS) elements are arranged two-dimensionally have been used in digital video cameras, digital still cameras, and the like.

[0003] One method for achieving simultaneous charge accumulation in a CMOS image sensor is a global shutter structure in which signals are temporarily stored in memory. In the global shutter structure, a memory is provided within each pixel, and charges accumulated in the light-receiving section are transferred to the memory for all pixels at once, and the charges are stored until readout is performed for each row, thereby aligning the exposure time for all pixels (see Patent Documents 1 and 2).

[0004] JP 2012-129797 A JP 2013-21533 A

[0005] Imaging devices such as CMOS image sensors are manufactured by manufacturing multiple chips on a substrate and then dicing them into individual chips. If moisture enters the chips from the sides of the individual chips, for example, condensation may occur, causing degradation of image quality and reducing the reliability of the imaging device.

[0006] The present disclosure has been made in view of the above circumstances, and aims to provide a photodetector, a semiconductor device, and a method for manufacturing a photodetector that can suppress a decrease in reliability.

[0007] A photodetector according to one aspect of the present disclosure includes a semiconductor substrate, an organic insulating film made of a light-transmitting organic material provided on a first surface side of the semiconductor substrate, a groove provided in the organic insulating film and the semiconductor substrate, the groove serving as a bottom surface of the semiconductor substrate, a first inorganic insulating film made of a light-transmitting inorganic material provided on the first surface side of the semiconductor substrate, the first inorganic insulating film covering the organic insulating film and filling the groove, and a second inorganic insulating film made of a light-transmitting inorganic material provided on the first inorganic insulating film. The semiconductor substrate has, on the first surface side, a first region located on one side of the groove and a second region located on the other side of the groove. The surface of the first inorganic insulating film is flat at least above the groove.

[0008] According to this, a groove separating the organic insulating film is present in the boundary region between the first and second regions, thereby preventing moisture from penetrating from the second region to the first region via the organic insulating film. Furthermore, the surface of at least a portion of the first inorganic insulating film located above the groove is flat, and the second inorganic insulating film is provided on this flat surface. Because the surface on which the second inorganic insulating film is to be formed is flat at least above the groove, it is easy to form the second inorganic insulating film with a uniform thickness. As a result, even if a seam (a minute gap) occurs in the first inorganic insulating film, the open end of the seam can be sealed with a second inorganic insulating film of uniform thickness, preventing moisture from penetrating into the interior of the photodetector through the open end of the seam. As a result, the moisture-proof performance of the photodetector can be improved, thereby suppressing a decrease in the reliability of the photodetector.

[0009] A semiconductor device according to one aspect of the present disclosure includes a semiconductor substrate, an organic insulating film made of an organic material provided on a first surface side of the semiconductor substrate, a groove provided in the organic insulating film and the semiconductor substrate, the groove serving as a bottom surface of the semiconductor substrate, a first inorganic insulating film made of an inorganic material provided on the first surface side of the semiconductor substrate, the first inorganic insulating film covering the organic insulating film and filling the groove, and a second inorganic insulating film made of an inorganic material provided on the first inorganic insulating film. The semiconductor substrate has, on the first surface side, a first region located on one side of the groove and a second region located on the other side of the groove. The surface of the first inorganic insulating film is flat at least above the groove.

[0010] According to this, a groove separating the organic insulating film is present in the boundary region between the first and second regions, thereby preventing moisture from penetrating from the second region to the first region via the organic insulating film. Furthermore, the surface of at least a portion of the first inorganic insulating film located above the groove is flat, and the second inorganic insulating film is provided on this flat surface. Because the surface on which the second inorganic insulating film is to be formed is flat at least above the groove, it is easy to form the second inorganic insulating film with a uniform thickness. As a result, even if a seam (a minute gap) occurs in the first inorganic insulating film, the open end of the seam can be sealed with a second inorganic insulating film of uniform thickness, preventing moisture from penetrating into the semiconductor device through the open end of the seam. As a result, the moisture-proof performance of the semiconductor device can be improved, thereby suppressing a decrease in the reliability of the semiconductor device.

[0011] A method for manufacturing a photodetector according to one aspect of the present disclosure includes the steps of: forming an organic insulating film made of a light-transmitting organic material on a first surface side of a semiconductor substrate; etching the organic insulating film and the semiconductor substrate to form grooves in the organic insulating film and the semiconductor substrate with the semiconductor substrate as a bottom surface; forming a first inorganic insulating film made of a light-transmitting inorganic material on the first surface side of the semiconductor substrate to cover the organic insulating film and fill the grooves; forming a planarization film on the first inorganic insulating film to planarize the surface on the first surface side of the semiconductor substrate; etching back the planarization film and the first inorganic insulating film to planarize the surface of the first inorganic insulating film at least above the grooves; and forming a second inorganic insulating film made of a light-transmitting inorganic material on the planarized surface of the first inorganic insulating film.

[0012] This makes it possible to manufacture an imaging device with high moisture-proofing properties and high reliability.

[0013] FIG. 1 is a block diagram illustrating an example of the overall configuration of an imaging device according to an embodiment of the present disclosure. FIG. 2 is a plan view illustrating an example of the configuration of a pixel region of an imaging device according to an embodiment of the present disclosure. FIG. 3 is a cross-sectional view illustrating an example of the configuration of an effective pixel region of a pixel region according to an embodiment of the present disclosure. FIG. 4 is a cross-sectional view illustrating an example of the configuration of a groove portion of a pixel region and its surrounding area according to an embodiment of the present disclosure. FIG. 5A is a cross-sectional view illustrating a method for manufacturing a pixel region according to an embodiment of the present disclosure. FIG. 5B is a cross-sectional view illustrating a method for manufacturing a pixel region according to an embodiment of the present disclosure. FIG. 5C is a cross-sectional view illustrating a method for manufacturing a pixel region according to an embodiment of the present disclosure. FIG. 5D is a cross-sectional view illustrating a method for manufacturing a pixel region according to an embodiment of the present disclosure. FIG. 5E is a cross-sectional view illustrating a method for manufacturing a pixel region according to an embodiment of the present disclosure. FIG. 5F is a cross-sectional view illustrating a method for manufacturing a pixel region according to an embodiment of the present disclosure. FIG. 6 is a cross-sectional view illustrating a configuration of a groove portion of a pixel region and its surrounding area according to a comparative example of the present disclosure. FIG. 7A is a cross-sectional view illustrating a method for manufacturing a pixel region according to a comparative example of the present disclosure. FIG. 7B is a cross-sectional view illustrating a method for manufacturing a pixel region according to a comparative example of the present disclosure. FIG. 7C is a cross-sectional view illustrating a method for manufacturing a pixel region according to a comparative example of the present disclosure. FIG. 7D is a cross-sectional view showing a manufacturing method of a pixel region according to a comparative example of the present disclosure. FIG. 8 is a cross-sectional view showing a configuration of an effective pixel region of a pixel region according to a first modification of an embodiment of the present disclosure. FIG. 9 is a cross-sectional view showing a configuration of a groove portion and its periphery in a pixel region according to a first modification of an embodiment of the present disclosure. FIG. 10 is a cross-sectional view showing a configuration of an effective pixel region of a pixel region according to a second modification of an embodiment of the present disclosure. FIG. 11 is a cross-sectional view showing a configuration of a groove portion and its periphery in a pixel region according to a second modification of an embodiment of the present disclosure. FIG. 12 is a cross-sectional view showing a configuration of an effective pixel region of a pixel region according to a third modification of an embodiment of the present disclosure. FIG. 13 is a cross-sectional view showing a configuration of a groove portion and its periphery in a pixel region according to a third modification of an embodiment of the present disclosure. FIG. 14 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied. FIG. 15 is a diagram showing an example of an installation position of an imaging unit.

[0014] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings referred to in the following description, identical or similar parts are designated by identical or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc., may differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, it goes without saying that the drawings may include parts with different dimensional relationships and ratios.

[0015] Furthermore, the definitions of directions such as up and down in the following explanation are merely for the convenience of explanation and do not limit the technical idea of ​​the present disclosure. For example, if an object is rotated 90 degrees and observed, up and down are converted to left and right and read as such, and if an object is rotated 180 degrees and observed, up and down are obviously read as reversed.

[0016] In the following description, directions may be described using the terms X-axis, Y-axis, and Z-axis. For example, the X-axis and Y-axis directions are directions parallel to the rear surface 10b of the semiconductor substrate 10. The Z-axis direction is the normal direction to the rear surface 10b of the semiconductor substrate 10 and is also the thickness direction of the semiconductor substrate 10. The X-axis, Y-axis, and Z-axis directions are perpendicular to each other.

[0017] In the following description, the term "planar view" means a view from the normal direction of the rear surface 10b of the semiconductor substrate 10, for example, a view from the Z-axis direction.

[0018] <Embodiment> (Overall Configuration Example of Imaging Device) Fig. 1 is a block diagram showing an overall configuration example of an imaging device 1 according to an embodiment of the present disclosure. The imaging device 1 is an example of a "photodetection device" of the present disclosure, and is, for example, a back-illuminated CMOS (Complementary Metal Oxide Semiconductor) image sensor used in electronic devices such as digital still cameras and digital video cameras. The imaging device 1 captures incident light (image light) from a subject via an optical lens system (not shown), converts the amount of incident light imaged on an imaging surface into an electrical signal on a pixel-by-pixel basis, and outputs the electrical signal as a pixel signal.

[0019] As shown in FIG. 1, the imaging device 1 includes a plurality of pixels 12 , a vertical drive circuit 13 , a column signal processing circuit 14 , a horizontal drive circuit 15 , an output circuit 16 , and a control circuit 17 .

[0020] Each pixel 12 is a light-receiving region that receives light collected by an optical system (not shown). The pixels 12 are arranged in a matrix in a pixel region 11 of a semiconductor substrate 10. The pixels 12 are connected row by row to a vertical drive circuit 13 via horizontal signal lines 22, and are connected column by column to a column signal processing circuit 14 via vertical signal lines 23. Each pixel 12 outputs a pixel signal at a level corresponding to the amount of light received. An image of the subject is constructed from these pixel signals.

[0021] The vertical drive circuit 13 sequentially supplies drive signals for driving (transferring, selecting, resetting, etc.) each of the pixels 12 to the pixels 12 for each row of the pixels 12 via horizontal signal lines 22. The column signal processing circuit 14 performs CDS (Correlated Double Sampling) processing on pixel signals output from the pixels 12 via vertical signal lines 23, thereby performing AD conversion of the pixel signals and removing reset noise.

[0022] The horizontal drive circuit 15 supplies drive signals to the column signal processing circuit 14 for causing the column signal processing circuit 14 to output pixel signals to data output signal lines 24, sequentially for each column of the pixels 12. The output circuit 16 amplifies the pixel signals supplied from the column signal processing circuit 14 via the data output signal lines 24 at timings according to the drive signals from the horizontal drive circuit 15, and outputs the amplified signals to a downstream signal processing circuit. The control circuit 17 controls the driving of each block within the imaging device 1. For example, the control circuit 17 generates clock signals according to the drive cycles of each block and supplies them to each block.

[0023] The pixel 12 includes a photodiode 31, a transfer transistor 32, a floating diffusion 33, an amplification transistor 34, a selection transistor 35, and a reset transistor 36. The transfer transistor 32, the floating diffusion 33, the amplification transistor 34, the selection transistor 35, and the reset transistor 36 configure a readout circuit 30 (an example of a "semiconductor device" in the present disclosure) that reads out the charge (pixel signal) photoelectrically converted by the photodiode 31.

[0024] The photodiode 31 is a photoelectric conversion unit that converts incident light into electric charges by photoelectric conversion and stores the electric charges, and has an anode terminal grounded and a cathode terminal connected to the transfer transistor 32. The transfer transistor 32 is driven in accordance with a transfer signal TRG supplied from the vertical drive circuit 13, and when the transfer transistor 32 is turned on, the electric charges stored in the photodiode 31 are transferred to the floating diffusion 33. The floating diffusion 33 is a floating diffusion region having a predetermined storage capacitance connected to the gate electrode of the amplification transistor 34, and temporarily stores the electric charges transferred from the photodiode 31.

[0025] The amplification transistor 34 outputs a pixel signal at a level corresponding to the charge accumulated in the floating diffusion 33 (i.e., the potential of the floating diffusion 33) to the vertical signal line 23 via the selection transistor 35. In other words, with the configuration in which the floating diffusion 33 is connected to the gate electrode of the amplification transistor 34, the floating diffusion 33 and the amplification transistor 34 function as a conversion unit that amplifies the charge generated in the photodiode 31 and converts it into a pixel signal at a level corresponding to the charge.

[0026] The selection transistor 35 is driven in accordance with a selection signal SEL supplied from the vertical drive circuit 13, and when the selection transistor 35 is turned on, the pixel signal output from the amplification transistor 34 is ready to be output to the vertical signal line 23. The reset transistor 36 is driven in accordance with a reset signal RST supplied from the vertical drive circuit 13, and when the reset transistor 36 is turned on, the charge accumulated in the floating diffusion 33 is discharged to the drain power supply Vdd, and the amount of charge in the floating diffusion 33 is reset.

[0027] (Configuration Example of Pixel Region) Fig. 2 is a plan view showing a configuration example of the pixel region 11 of the imaging device 1 according to an embodiment of the present disclosure. As shown in Fig. 2, the pixel region 11 has an effective pixel region 111 (an example of a "first region" in the present disclosure), an ineffective pixel region 112 (an example of a "second region" in the present disclosure) disposed between the effective pixel region 111 and the outer periphery of the semiconductor substrate 10, and a boundary region 113 disposed between the effective pixel region 111 and the ineffective pixel region 112. For example, in the X-axis direction and the Y-axis direction, the ineffective pixel region 112 is disposed on both ends of the effective pixel region 111 with the boundary region 113 interposed therebetween. In a plan view, the effective pixel region 111 is surrounded by the ineffective pixel region 112 with the boundary region 113 interposed therebetween.

[0028] The effective pixel region 111 has pixels 12 (see FIG. 1) provided on the semiconductor substrate 10, and outputs signals generated by photoelectric conversion in the pixels 12. For example, in the effective pixel region 111, a plurality of pixels 12 are arranged side by side in the row and column directions. Hereinafter, the pixels 12 provided in the effective pixel region 111 will also be referred to as effective pixels. The effective pixels are connected to a column signal processing circuit 14 (see FIG. 1) via vertical signal lines 23 (see FIG. 1). The effective pixels receive incident light, amplify pixel signals generated by photoelectric conversion, and output the amplified signals to the column signal processing circuit 14.

[0029] The invalid pixel region 112 does not output a signal resulting from photoelectric conversion. For example, in the invalid pixel region 112, a plurality of pixels 12 are arranged side by side in the row and column directions. Hereinafter, the pixels 12 provided in the invalid pixel region 11B are also referred to as invalid pixels. The invalid pixels are not connected to the column signal processing circuit 14 (see FIG. 1 ) and do not output pixel signals to the column signal processing circuit 14. Alternatively, the invalid pixel region 11B may not have any pixels 12 provided therein.

[0030] A groove H is provided in the boundary region 113. In a plan view, the groove H surrounds the effective pixel region 11A without any gaps. An example of the configuration of the groove H and its surrounding area will be described later with reference to FIG.

[0031] Fig. 3 is a cross-sectional view showing a configuration example of the effective pixel region 111 of the pixel region 11 according to an embodiment of the present disclosure. The cross-sectional view shown in Fig. 3 is an enlarged view of a cross section taken along line A-A' in the plan view shown in Fig. 2. Fig. 4 is a cross-sectional view showing a configuration example of the groove H of the pixel region 11 and its surrounding area according to an embodiment of the present disclosure. The cross-sectional view shown in Fig. 4 is an enlarged view of a cross section taken along line B-B' in the plan view shown in Fig. 2.

[0032] 3 , the imaging device 1 includes a semiconductor substrate 10, an anti-reflection film 51 made of a light-transmitting material provided on the back surface 10b (top surface in FIGS. 3 and 4 ) of the semiconductor substrate 10, an inorganic insulating film 53 made of a light-transmitting inorganic material provided on the anti-reflection film 51, an organic insulating film 55 made of a light-transmitting organic material provided on the inorganic insulating film 53 (an example of a “first organic insulating film” in the present disclosure), a color filter CF provided on the organic insulating film 55, an organic insulating film 57 made of a light-transmitting organic material provided on the color filter CF (an example of a “second organic insulating film” in the present disclosure), an inorganic insulating film 61 made of a light-transmitting inorganic material provided on the organic insulating film 57 (an example of a “first inorganic insulating film” in the present disclosure), and an inorganic insulating film 63 made of a light-transmitting inorganic material provided on the inorganic insulating film 61 (an example of a “second inorganic insulating film” in the present disclosure). The color filter CF is located between the organic insulating film 55 and the organic insulating film 57. The laminated film of the anti-reflection film 51 and the inorganic insulating film 53 is an example of the "insulating film" of the present disclosure.

[0033] A light-transmitting material means a material that can transmit light of a wavelength component to be detected (for example, visible light, infrared light, or the like). The light-transmitting material is preferably colorless and transparent, but is not limited thereto and may be colored and transparent. The same applies to light-transmitting inorganic materials and light-transmitting organic materials.

[0034] 3 and 4 , the semiconductor substrate 10 has a front surface 10a and a back surface 10b (an example of a "first surface" in the present disclosure) and is made of, for example, silicon. The semiconductor substrate 10 has photodiodes (PDs) 31 of a plurality of pixels 12 arranged in a two-dimensional matrix. For example, in the pixel region 11 of the semiconductor substrate 10, the photodiodes 31 of effective pixels are arranged in the effective pixel region 111, the photodiodes 31 of ineffective pixels are arranged in the ineffective pixel region 112, and no pixels are arranged in the boundary region 113 between the effective pixel region 111 and the ineffective pixel region 112. Alternatively, no pixels may be arranged in the ineffective pixel region 112 as well as in the boundary region 113.

[0035] As shown in FIG. 3 , in the effective pixel region 111, an element isolation portion 41 is provided between the photodiode 31 of one pixel 12 and the photodiode 31 of the other pixel 12 that are adjacent to each other in the X-axis direction and the Y-axis direction. The element isolation portion 41 electrically isolates the adjacent photodiodes 31. The element isolation portion 41 is configured, for example, with a trench provided from the back surface 10 b toward the front surface 10 a of the semiconductor substrate 10 and an insulating film (e.g., a silicon oxide film) embedded in the trench. The trench may or may not penetrate the semiconductor substrate 10 in the thickness direction (e.g., the Z-axis direction). FIG. 3 illustrates an example in which the trench does not penetrate the semiconductor substrate 10 (i.e., the trench is provided to a midpoint in the depth direction of the semiconductor substrate 10).

[0036] 3 and 4 has a laminated structure in which, for example, a fixed charge film and an oxide film are laminated, and for example, a high-dielectric-constant (High-k) insulating thin film formed by the ALD (Atomic Layer Deposition) method can be used. Specifically, hafnium oxide (HfO２ ) and aluminum oxide (Al ２ O ３ ), titanium oxide (TiO ２ ), STO (Strontium Titan Oxide), etc. As an example, the anti-reflection film 51 may be configured by laminating a hafnium oxide film, an aluminum oxide film, and a silicon oxide film.

[0037] The inorganic insulating film 53 is made of, for example, silicon oxide (SiO ２ Alternatively, the inorganic insulating film 53 may be a silicon nitride (SiN) film, a silicon oxynitride (SiON) film, or the like. The inorganic insulating film 53 may be a silicon oxide (SiO ２ The film may be a laminated film including at least one of a silicon nitride (SiN) film, a silicon oxynitride (SiON) film, and a silicon nitride (SiON) film.

[0038] The organic insulating film 55 is a planarizing film for planarizing the base of the color filters CF. The organic insulating film 55 is made of a light-transmitting organic material such as an acrylic resin or a styrene resin.

[0039] The color filter CF is provided on the organic insulating film 55. The color filter CF has a plurality of filter components. For example, the color filter CF has a first filter component, a second filter component, and a third filter component for each pixel 12. As an example, the first filter component, the second filter component, and the third filter component are a green filter component (G), a red filter component (R), and a blue filter component (B), respectively.

[0040] The first, second, and third filter components are not limited to those described above and may be any color filter components. Furthermore, at least one of the first, second, and third filter components may be a filter component other than a color filter component, such as a transparent resin that transmits visible light or an ND filter that attenuates visible light, such as a transparent resin with a carbon black pigment added thereto. The filter components of each pixel 12 are isolated from one another by partitions 43.

[0041] The organic insulating film 57 is a planarizing film for planarizing the surface above the color filters CF. The organic insulating film 57 is made of a light-transmitting organic material such as an acrylic resin or a styrene resin.

[0042] The inorganic insulating film 61 is, for example, a silicon nitride (SiN) film. Alternatively, the inorganic insulating film 61 is, for example, a silicon oxide (SiO ２ ) film, a silicon oxynitride (SiON) film, or the like. In the effective pixel region 111, an on-chip lens OCL (an example of a "lens body" in the present disclosure) is provided on the light incident surface side (the upper surface side in FIGS. 3 and 4 ) of the inorganic insulating film 61. For example, one on-chip lens 90 is arranged for each of the plurality of pixels 12.

[0043] The inorganic insulating film 63 is, for example, a silicon nitride (SiN) film. Alternatively, the inorganic insulating film 61 is, for example, a silicon oxide (SiO ２ ) film, silicon oxynitride (SiON) film, or the like.

[0044] In order to suppress reflection of light incident on the on-chip lens OCL at the interface between the on-chip lens OCL and the inorganic insulating film 63, it is preferable that the inorganic insulating film 63 be made of the same material as the inorganic insulating film 61 that constitutes the on-chip lens OCL, or a material having a lower refractive index than the inorganic insulating film 61.

[0045] For example, when the inorganic insulating film 61 is a SiN film, the inorganic insulating film 63 is a SiN film, a SiON film, or a SiO ２ It is preferable that the film is a SiON film or a SiO ２ When the inorganic insulating film 61 is a SiON film, the inorganic insulating film 63 is a SiON film or a SiO ２ It is preferably a film. ２ The inorganic insulating film 61 has a lower refractive index than the SiON film. ２ In the case of a film, the inorganic insulating film 63 is also made of SiO ２ Preferably it is a membrane.

[0046] 4, the groove H is provided in the organic insulating film 57, the organic insulating film 55, the inorganic insulating film 53, the anti-reflection film 51, and the semiconductor substrate 10, and the semiconductor substrate 10 serves as the bottom surface HB. The side surfaces of the groove H are inclined so that the width of the groove H increases (i.e., in a forward tapered shape) as the groove H approaches the opening side (upper side in FIG. 4) of the groove H from the bottom surface HB of the groove H. The width of the groove H is the length in the X-axis direction in FIG. 4.

[0047] For example, the side of the groove portion H has a side HSb (an example of the "first side" in the present disclosure) provided on the semiconductor substrate 10, a side HSm (an example of the "third side" in the present disclosure) provided on the anti-reflection film 51 and the inorganic insulating film 53, and a side HSt (an example of the "second side" in the present disclosure) provided on the organic insulating film 55 and the organic insulating film 57.

[0048] The side surfaces HSb, HSm, and HSt are each inclined (i.e., forward tapered) so that the width of the groove H increases as the groove H approaches the opening from the bottom surface HB of the groove H. Furthermore, the side surface HSt is recessed relative to the side surfaces HSm and HSb in the direction in which the width of the groove H increases. A step is generated between the side surface HSt and the side surface HSm.

[0049] The inorganic insulating film 61 covers the organic insulating films 55 and 57 and fills the groove H. As described above, the side surfaces of the groove H are inclined in a forward tapered shape, which makes it easier to fill the groove H with the inorganic insulating film 61 without gaps compared to, for example, a case in which the side surfaces are inclined in a reverse tapered shape.

[0050] 4, the surface of the inorganic insulating film 61 (i.e., the interface of the inorganic insulating film 61 with the inorganic insulating film 63) is continuously flat from the effective pixel region 111 around the groove H, passing above the groove H, to the ineffective pixel region 112. This makes it easy to form the inorganic insulating film 63 with a uniform thickness from the effective pixel region 111 around the groove H, passing above the groove H, to the ineffective pixel region 112.

[0051] Here, the deposition surfaces of the inorganic insulating film 61 that are filled into the trench H are the bottom surface HB and side surfaces HSb, HSm, and HSt of the trench H. The bottom surface HB of the trench H is a flat surface that is parallel or nearly parallel to the rear surface 10b of the semiconductor substrate 10. The side surfaces HSb, HSm, and HSt of the trench H are inclined surfaces that are inclined with respect to the rear surface 10b of the semiconductor substrate 10. The inclination angles of the side surfaces HSb, HSm, and HSt are different from one another.

[0052] 4, when there are multiple regions with different inclination angles on the surface to be deposited, seams are likely to occur starting from corners between adjacent regions (for example, the corner between the bottom surface HB and the side surface HSb, the corner between the side surface HSb and the side surface HSm, the corner between the top surface of the inorganic insulating film 53 and the side surface HSt, etc.). A seam is a minute gap that occurs during deposition.

[0053] 4 , even when a seam 611 occurs in the inorganic insulating film 61 filling the groove H, the opening end 611E of the seam 611 (i.e., the portion of the seam 611 that is exposed on the surface of the inorganic insulating film 61) can be covered with the inorganic insulating film 63. As described above, the inorganic insulating film 63 is formed to a uniform thickness from the effective pixel region 111 around the groove H, passing above the groove H, to the ineffective pixel region 112, and therefore the opening end 611E of the seam 611 can be closed with high reproducibility.

[0054] 4 shows a state in which no color filter CF is arranged in the region of the effective pixel region 111 adjacent to the groove portion H, but the present embodiment is not limited to this. In an embodiment of the present disclosure, a color filter CF may also be arranged in the region of the effective pixel region 111 adjacent to the groove portion H, as in FIG.

[0055] Although not shown, the front surface 10a of the semiconductor substrate 10 is provided with a gate electrode (i.e., a transfer gate) of the transfer transistor 32, an amplification transistor 34, a selection transistor 35, a reset transistor 36 (see FIG. 1), and wiring layers connected to these.

[0056] (Manufacturing Method) Next, a manufacturing method of the imaging device 1 according to an embodiment of the present disclosure will be described. Here, a manufacturing method of the imaging device 1 including the configuration shown in FIG. 4 will be described. Note that the imaging device 1 is manufactured using various types of apparatus, such as a film forming apparatus (including a CVD (chemical vapor deposition) apparatus, a sputtering apparatus, and an ALD apparatus), an etching apparatus, and a CMP (Chemical Mechanical Polishing) apparatus. Hereinafter, these apparatuses will be collectively referred to as manufacturing apparatuses.

[0057] 5A to 5F are cross-sectional views showing a manufacturing method of the pixel region 11 according to the embodiment of the present disclosure, which correspond to the groove H and its surrounding area of ​​the pixel region 11 shown in FIG.

[0058] 5A, the manufacturing equipment forms an anti-reflection film 51 on the rear surface 10b of the semiconductor substrate 10. Next, the manufacturing equipment forms an inorganic insulating film 53 on the anti-reflection film 51. Next, the manufacturing equipment forms an organic insulating film 55 on the inorganic insulating film 53. The organic insulating film 55 is formed by, for example, a spin coating method. This flattens the base of the color filter CF (see FIG. 3) to be formed in the next process. Next, the manufacturing equipment forms the color filter CF on the organic insulating film 55 in the effective pixel region 111 (see FIG. 3).

[0059] Next, the manufacturing equipment forms an organic insulating film 57. The organic insulating film 57 is formed on the color filter CF in the effective pixel region 111, and on the organic insulating film 55 in the ineffective pixel region 112 and the boundary region 113 (see FIG. 4). The organic insulating film 57 is formed by, for example, spin coating. This flattens the surface above the color filter CF (see FIG. 3).

[0060] Next, the manufacturing equipment forms a resist pattern 71 on the organic insulating film 55. The resist pattern 71 has a shape that opens above the region where the groove H is to be formed and covers the other regions, for example. Next, as shown in FIG. 5B , the manufacturing equipment uses the resist pattern 71 as a mask to dry-etch the organic insulating films 57 and 55, the inorganic insulating film 53, the anti-reflection film 51, and the back surface 10b side of the semiconductor substrate 10 in this order, to form the groove H. After the groove H is formed, the manufacturing equipment removes the resist pattern 71 as shown in FIG. 5C .

[0061] Next, as shown in FIG. 5D , the manufacturing equipment forms an inorganic insulating film 61 on the rear surface 10b of the semiconductor substrate 10 to cover the organic insulating film 57 and fill the trenches H. The inorganic insulating film 61 is formed, for example, by a CVD method. As described with reference to FIG. 4 , the surface of the inorganic insulating film 61 that is to be filled into the trenches H has multiple regions with different inclination angles, which may result in seams 611. In addition, a recess 612 that reflects the shape of the trenches H is formed on the surface of the inorganic insulating film 61.

[0062] 5E , the manufacturing equipment forms an organic insulating film 73 (an example of the "planarizing film" of the present disclosure) on the inorganic insulating film 61. The organic insulating film 73 is formed by, for example, a spin coating method. As a result, the recess 612 is filled with the organic insulating film 73, and the upper part of the back surface 10b of the semiconductor substrate 10 is planarized.

[0063] Next, the manufacturing equipment partially forms a photoresist 75 on the inorganic insulating film 61. The shape of the photoresist 75 is the same as or almost the same as the shape of the on-chip lens OCL (see FIGS. 3 and 4), for example. The photoresist 75 is formed only above the region where the on-chip lens OCL is to be formed.

[0064] Next, the manufacturing equipment etches back the organic insulating film 73 on which the photoresist 75 is provided and the inorganic insulating film 61 located thereunder. As a result, as shown in Fig. 5F, the surface of the inorganic insulating film 61 is planarized from the effective pixel region 111 (see Fig. 4) around the groove H, passing above the groove H, to the ineffective pixel region 112 (see Fig. 4). Furthermore, in the effective pixel region 111, an on-chip lens OCL reflecting the shape of the photoresist 75 is formed.

[0065] In this etch-back, it is preferable to set the dry etching conditions so that the etching rate of the organic insulating film 73 is the same or almost the same as the etching rate of the inorganic insulating film 61. It is more preferable to set the dry etching conditions so that the etching rate of the photoresist 75, the etching rate of the organic insulating film 73, and the etching rate of the inorganic insulating film 61 are the same or almost the same as the etching rate of the photoresist 75.

[0066] Next, the manufacturing equipment forms the on-chip lenses OCL in the effective pixel region 111 and forms the inorganic insulating film 63 (see FIGS. 3 and 4) on the inorganic insulating film 61 with the upper portions of the grooves H planarized. Through the above steps, the pixel region 11 shown in FIGS. 3 and 4 is completed.

[0067] Comparative Example Next, a comparative example to be compared with the embodiment of the present disclosure will be described. FIG. 6 is a cross-sectional view showing the configuration of the groove H' and its surrounding area in the pixel region 11' according to the comparative example of the present disclosure. In the comparative example shown in FIG. 6, the bottom surface of the groove H' is exposed from the inorganic insulating films 61 and 63. Furthermore, the side surface of the groove H' is covered with the inorganic insulating film 63, not the inorganic insulating film 61. Since the surface on which the inorganic insulating film 63 is formed has multiple regions with different inclination angles, a seam 631 occurs in the inorganic insulating film 63. The open end of the seam 631 is not covered with other inorganic insulating films and is exposed.

[0068] 7A to 7D are cross-sectional views showing a manufacturing method of a pixel region 11′ according to a comparative example of the present disclosure. As shown in FIG. 7A , in the manufacturing method of the pixel region 11′ according to the comparative example, after forming an on-chip lens OCL in the inorganic insulating film 61, a resist pattern 71′ is formed. The resist pattern 71′ has a shape that opens above a region where a groove H′ is to be formed and covers the other regions. Next, as shown in FIG. 7B , the manufacturing equipment uses the resist pattern 71′ as a mask to dry-etch the inorganic insulating film 61, the organic insulating films 57 and 55, the inorganic insulating film 53, the anti-reflection film 51, and the back surface 10b side of the semiconductor substrate 10 in this order, thereby forming the groove H′. After the groove H′ is formed, the manufacturing equipment removes the resist pattern 71′.

[0069] Next, as shown in Fig. 7C, the manufacturing equipment forms an inorganic insulating film 63. At this time, a seam 631 is generated in the inorganic insulating film 63. Thereafter, as shown in Fig. 7D, the manufacturing equipment etches back the inorganic insulating film 63. Through the above steps, the pixel region 11' shown in Fig. 6 is completed.

[0070] In a comparative example, a method of further forming another insulating film (not shown) on the inorganic insulating film 63 on which the seam 631 is formed is also conceivable. However, even when this method is adopted, the inorganic insulating film 61, which is the surface on which the other insulating film is to be formed, has a plurality of regions with different inclination angles, and therefore the other insulating film is likely to be formed with an uneven thickness, and it is considered difficult to completely prevent the opening edge of the seam 631 from leaking. Furthermore, because another insulating film is also formed on the on-chip lens OCL, there is a possibility that the optical characteristics of the on-chip lens OCL may fluctuate.

[0071] Effect of the Embodiment As described above, the imaging device 1 according to the embodiment of the present disclosure includes the semiconductor substrate 10, the organic insulating films 55, 57 made of a light-transmitting organic material and provided on the back surface 10b of the semiconductor substrate 10, the groove H provided in the organic insulating films 55, 57 and the semiconductor substrate 10 and having the semiconductor substrate 10 as a bottom surface, the inorganic insulating film 61 made of a light-transmitting inorganic material and provided on the back surface 10b of the semiconductor substrate 10, covering the organic insulating films 55, 57 and filling the groove H, and the inorganic insulating film 63 made of a light-transmitting inorganic material and provided on the inorganic insulating film 61. On the back surface 10b side, the semiconductor substrate 10 has an effective pixel region 111 located on one side of the groove H and an ineffective pixel region 112 located on the other side of the groove H. The surface of the inorganic insulating film 61 is flat at least above the groove H. More preferably, the surface of the inorganic insulating film 61 is continuously flat from the effective pixel region 111 around the groove H, passing above the groove H, to the ineffective pixel region 112 .

[0072] According to this, a groove H separating the organic insulating films 55 and 57 is present in the boundary region 113 between the effective pixel region 111 and the ineffective pixel region 112, thereby preventing moisture from penetrating from the ineffective pixel region 112 to the effective pixel region 111 via the organic insulating films 55 and 57. Furthermore, the surface of at least the portion of the inorganic insulating film 61 located above the groove H is flat, and the inorganic insulating film 63 is provided on this flat surface. Because the surface on which the inorganic insulating film 63 is formed is flat at least above the groove H, it is easy to form the inorganic insulating film 63 to a uniform thickness. As a result, even if a seam 611 (a minute gap) occurs in the inorganic insulating film 61, the open end of the seam 611 can be sealed with the inorganic insulating film 63 of a uniform thickness, preventing moisture from penetrating into the interior of the imaging device 1 through the open end of the seam 611. As a result, the moisture-proof performance of the imaging device 1 can be improved, thereby suppressing a decrease in the reliability of the imaging device 1.

[0073] Furthermore, the inorganic insulating film 61 covers the organic insulating films 55 and 57 and fills the grooves H. The portions of the inorganic insulating film 61 that are filled in the grooves H laterally support the organic insulating films 55 and 57 and function as side walls. This makes it possible to suppress the effects of unintended stress even when it is applied between the color filter CF, the organic insulating films 55 and 57, and the inorganic insulating films 61 and 63.

[0074] In the above-described imaging device 1, it is preferable that the effective pixel region 111 is surrounded by the groove portion H. This allows the organic insulating films 55, 57 to be completely separated between the effective pixel region 111 and the ineffective pixel region 112, and further prevents moisture from entering the effective pixel region 111 from the ineffective pixel region 112 via the organic insulating films 55, 57.

[0075] A manufacturing method of an imaging device 1 according to an embodiment of the present disclosure includes the steps of forming organic insulating films 55, 57 made of a light-transmitting organic material on the back surface 10b of the semiconductor substrate 10, etching the organic insulating films 55, 57 and the semiconductor substrate 10 to form grooves H in the organic insulating films 55, 57 and the semiconductor substrate 10, with the semiconductor substrate 10 as a bottom surface, forming an inorganic insulating film 61 made of a light-transmitting inorganic material on the back surface 10b of the semiconductor substrate 10 to cover the organic insulating films 55, 57 and fill the grooves H, forming an organic insulating film 73 on the inorganic insulating film 61 to planarize the surface of the back surface 10b of the semiconductor substrate 10, etching back the organic insulating film 73 and the inorganic insulating film 61 to planarize the surface of the inorganic insulating film 61 at least above the grooves H, and forming the inorganic insulating film 63 made of a light-transmitting inorganic material on the planarized surface of the inorganic insulating film 61. This method makes it possible to manufacture an imaging device 1 with high moisture resistance and high reliability.

[0076] 3 and 4, the imaging device 1 has been described as having the organic insulating films 55 and 57. However, in an embodiment of the present disclosure, either one or both of the organic insulating films 55 and 57 may be omitted.

[0077] (1) Modification 1 Fig. 8 is a cross-sectional view showing the configuration of the effective pixel region 111 of the pixel region 11A according to Modification 1 of the embodiment of the present disclosure. Fig. 9 is a cross-sectional view showing the configuration of the groove portion H and its surrounding area of ​​the pixel region 11A according to Modification 1 of the embodiment of the present disclosure. The pixel region 11A shown in Figs. 8 and 9 is a modification of the pixel region 11 shown in Figs. 3 and 4. As shown in Figs. 8 and 9, the pixel region 11A does not have an organic insulating film 55.

[0078] 8, in the effective pixel region 111, the color filter CF is disposed on the inorganic insulating film 53 without the organic insulating film 55 therebetween. Also, as shown in Fig. 9, in the region of the effective pixel region 111 adjacent to the groove portion H and in the ineffective pixel region 114, the organic insulating film 57 is disposed on the inorganic insulating film 53 without the organic insulating film 55 therebetween.

[0079] Even in this configuration, the imaging device 1 achieves the same effects as the above-described embodiment. That is, even if a seam 611 (a minute gap) occurs in the inorganic insulating film 61, the open end of the seam 611 can be sealed with the inorganic insulating film 63 having a uniform thickness, thereby preventing moisture from penetrating into the imaging device 1 through the open end of the seam 611. This improves the moisture-proof performance of the imaging device 1, thereby making it possible to suppress a decrease in the reliability of the imaging device 1.

[0080] (2) Modification 2 Figure 10 is a cross-sectional view showing the configuration of the effective pixel region 111 of the pixel region 11B according to Modification 2 of the embodiment of the present disclosure. Figure 11 is a cross-sectional view showing the configuration of the groove portion H and its surrounding area of ​​the pixel region 11B according to Modification 2 of the embodiment of the present disclosure. The pixel region 11B shown in Figures 10 and 11 is a modification of the pixel region 11 shown in Figures 3 and 4. As shown in Figures 10 and 11, the pixel region 11B does not have an organic insulating film 57.

[0081] 10 , in the effective pixel region 111, the inorganic insulating film 61 is disposed on the color filter CF without the organic insulating film 57 therebetween. Also, as shown in Fig. 11 , in the region of the effective pixel region 111 adjacent to the groove portion H and in the ineffective pixel region 114, the inorganic insulating film 61 is disposed on the organic insulating film 55 without the organic insulating film 57 therebetween. Even in this configuration, the imaging device 1 achieves the same effects as the above-described embodiment.

[0082] (3) Modification 3 Fig. 12 is a cross-sectional view showing the configuration of the effective pixel region 111 of a pixel region 11C according to Modification 3 of the embodiment of the present disclosure. Fig. 13 is a cross-sectional view showing the configuration of the groove H and its surrounding area of ​​the pixel region 11C according to Modification 3 of the embodiment of the present disclosure. The pixel region 11C shown in Figs. 12 and 13 is a modification of the pixel region 11 shown in Figs. 3 and 4. As shown in Figs. 12 and 13, neither of the organic insulating films 55, 57 is provided in the pixel region 11C.

[0083] 12, in the effective pixel region 111, the color filter CF is sandwiched from above and below between the inorganic insulating films 53 and 61 without the organic insulating films 55 and 57 interposed therebetween. Also, as shown in Fig. 13, in the region of the effective pixel region 111 adjacent to the groove portion H and in the ineffective pixel region 114, the inorganic insulating film 61 is disposed on the inorganic insulating film 53 without the organic insulating films 55 and 57 interposed therebetween. Even in this configuration, the imaging device 1 achieves the same effects as the above-described embodiment.

[0084] <Application to a Mobile Body> The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of mobile body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot.

[0085] FIG. 14 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied.

[0086] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 14, 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. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053.

[0087] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0088] The body system control unit 12020 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0089] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture images outside the vehicle and receives the captured images. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, characters on the road surface, etc. based on the received images.

[0090] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0091] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0092] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0093] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0094] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0095] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of Fig. 14, the output devices are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0096] FIG. 15 is a diagram showing an example of the installation position of the imaging unit 12031.

[0097] In FIG. 15 , a vehicle 12100 has imaging units 12101, 12102, 12103, 12104, and 12105 as the imaging unit 12031.

[0098] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided on the front nose and the imaging unit 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The forward images acquired by the imaging units 12101 and 12105 are mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0099] 15 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, by overlaying the image data captured by the imaging units 12101 to 12104, an overhead image of the vehicle 12100 viewed from above can be obtained.

[0100] At least one of the image capturing units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the image capturing units 12101 to 12104 may be a stereo camera made up of multiple image capturing elements, or may be an image capturing element having pixels for phase difference detection.

[0101] For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which runs autonomously without relying on driver operation.

[0102] For example, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines a collision risk that indicates the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0103] At least one of the image capturing units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether a pedestrian is present in the images captured by the image capturing units 12101 to 12104. Such pedestrian recognition is performed, for example, by extracting feature points from the images captured by the image capturing units 12101 to 12104 as infrared cameras and performing pattern matching on a series of feature points that indicate the outline of an object to determine whether the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the image capturing units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular outline on the recognized pedestrian for emphasis. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0104] The foregoing has described an example of a vehicle control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the imaging unit 12031 and other components of the above-described configuration. Specifically, the imaging device 1 having the configuration shown in FIGS. 1 to 4 can be applied to the imaging unit 12031. By applying the technology according to the present disclosure to the imaging unit 12031, it is possible to improve the moisture-proof performance of the imaging device included in the imaging unit 12031 and suppress a decrease in reliability.

[0105] <Other Embodiments> As described above, the present disclosure has been described using embodiments, modifications, and application examples. However, the descriptions and drawings that form part of this disclosure should not be understood as limiting the present disclosure. Various alternative embodiments, examples, and application techniques will become apparent to those skilled in the art from this disclosure. For example, the "photodetector" and "semiconductor device" of the present disclosure are not limited to application to imaging devices such as back-illuminated CMOS image sensors. The "photodetector" of the present disclosure may also be applied to distance measuring devices such as Time of Flight (ToF). Furthermore, the "semiconductor device" of the present disclosure may also be applied to various semiconductor devices, such as logic ICs (integrated circuits) such as central processing units (CPUs) and digital signal processors (DSPs), analog ICs, digital-to-analog (D / A) converters, analog-to-digital (A / D) converters, dynamic random access memories (DRAMs), and memory ICs such as NAND.

[0106] As such, the present technology naturally includes various embodiments not described herein. At least one of various omissions, substitutions, and modifications of components can be made without departing from the spirit of the above-described embodiments. Furthermore, the effects described in this specification are merely examples and are not intended to be limiting, and other effects may also be present.

[0107] The present disclosure may also be configured as follows: (1) A photodetector comprising: a semiconductor substrate; an organic insulating film made of a light-transmitting organic material provided on a first surface side of the semiconductor substrate; a groove provided on the organic insulating film and the semiconductor substrate, the groove serving as a bottom surface of the semiconductor substrate; a first inorganic insulating film made of a light-transmitting inorganic material provided on the first surface side of the semiconductor substrate, covering the organic insulating film and filling the groove; and a second inorganic insulating film made of a light-transmitting inorganic material provided on the first inorganic insulating film, wherein the semiconductor substrate has, on the first surface side, a first region located on one side of the groove and a second region located on the other side of the groove, and wherein the surface of the first inorganic insulating film is flat at least above the groove. (2) The photodetector according to (1), wherein the first region is surrounded by the groove. (3) The photodetector according to (2), wherein the first region is an effective pixel region that has pixels provided on the semiconductor substrate and outputs signals generated by photoelectric conversion in the pixels, and the second region is an ineffective pixel region that does not output signals by photoelectric conversion. (4) The photodetector according to any one of (1) to (3), wherein a side surface of the groove has a first side surface provided on the semiconductor substrate and a second side surface provided on the organic insulating film, and the second side surface is recessed from the first side surface in a direction in which the width of the groove increases. (5) The photodetector according to any one of (1) to (4), wherein an insulating film made of a light-transmitting material is provided between the first surface of the semiconductor substrate and the organic insulating film. (6) The photodetector according to (5), wherein the groove is provided in the organic insulating film, the insulating film, and the semiconductor substrate, and a side surface of the groove has a first side surface provided on the semiconductor substrate, a second side surface provided on the organic insulating film, and a third side surface provided on the insulating film, and the second side surface is recessed from the third side surface in a direction in which the width of the groove increases. (7) The photodetector according to any one of (1) to (6), wherein the organic insulating film has a first organic insulating film, and a second organic insulating film provided on the first organic insulating film.(8) The photodetector according to (7), further comprising a color filter provided on the first surface side of the semiconductor substrate, wherein the color filter is located between the first organic insulating film and the second organic insulating film. (9) The photodetector according to any one of (1) to (8), further comprising a lens body provided on the first inorganic insulating film. (10) A semiconductor device comprising: a semiconductor substrate; an organic insulating film made of an organic material provided on the first surface side of the semiconductor substrate; a groove provided in the organic insulating film and the semiconductor substrate, the groove having the semiconductor substrate as a bottom surface; a first inorganic insulating film made of an inorganic material provided on the first surface side of the semiconductor substrate, covering the organic insulating film and filling the groove; and a second inorganic insulating film made of an inorganic material provided on the first inorganic insulating film, wherein the semiconductor substrate has, on the first surface side, a first region located on one side of the groove and a second region located on the other side of the groove, and the surface of the first inorganic insulating film is flat at least above the groove. (11) A method for manufacturing a photodetector, comprising: a step of forming an organic insulating film made of a light-transmitting organic material on a first surface side of a semiconductor substrate; a step of etching the organic insulating film and the semiconductor substrate to form grooves in the organic insulating film and the semiconductor substrate, with the semiconductor substrate as a bottom surface; a step of forming a first inorganic insulating film made of a light-transmitting inorganic material on the first surface side of the semiconductor substrate to cover the organic insulating film and fill the grooves; a step of forming a planarization film on the first inorganic insulating film to planarize the surface on the first surface side of the semiconductor substrate; a step of etching back the planarization film and the first inorganic insulating film to planarize the surface of the first inorganic insulating film at least above the grooves; and a step of forming a second inorganic insulating film made of a light-transmitting inorganic material on the planarized surface of the first inorganic insulating film.

[0108] REFERENCE SIGNS LIST 1 Imaging device 10 Semiconductor substrate 10a Front surface 10b Back surface 11 Pixel region 11A Effective pixel region 11B Invalid pixel region 12 Pixel 13 Vertical drive circuit 14 Column signal processing circuit 15 Horizontal drive circuit 16 Output circuit 17 Control circuit 22 Horizontal signal line 23 Vertical signal line 24 Data output signal line 30 Readout circuit 31 Photodiode (PD) 32 Transfer transistor 33 Floating diffusion 34 Amplification transistor 35 Selection transistor 36 Reset transistor 41 Element isolation section 43 Partition 51 Anti-reflection film 53, 61, 63 Inorganic insulating film 55, 57, 73 Organic insulating film 71 Resist pattern 75 Photoresist 90 On-chip lens 111 Effective pixel region 112 Invalid pixel region 113 Boundary region 611 Seam 611E Opening edge 612 Recess 631 Seam 12000 Vehicle control system 12001 Communication network 12010 Drive system control unit 12020 Body system control unit 12030 Outside vehicle information detection unit 12031 Imaging unit 12040 Inside vehicle information detection unit 12041 Driver state detection unit 12050 Integrated control unit 12051 Microcomputer 12052 Audio / image output unit 12061 Audio speaker 12062 Display unit 12063 Instrument panel 12100 Vehicle 12101, 12102, 12103, 12104, 12105 Imaging unit 12111, 12112, 12113, 12114 Imaging range CF Color filter H Groove HB Bottom HSb, HSm, HSt Side I In-vehicle network OCL On-chip lens

Claims

1. A photodetector comprising: a semiconductor substrate; an organic insulating film made of a light-transmitting organic material provided on a first surface side of the semiconductor substrate; a groove provided on the organic insulating film and the semiconductor substrate, the groove being the bottom surface of the semiconductor substrate; a first inorganic insulating film made of a light-transmitting inorganic material provided on the first surface side of the semiconductor substrate, covering the organic insulating film and filling the groove; and a second inorganic insulating film made of a light-transmitting inorganic material provided on the first inorganic insulating film, wherein the semiconductor substrate has, on the first surface side, a first region located on one side of the groove and a second region located on the other side of the groove, and a surface of the first inorganic insulating film is flat at least above the groove.

2. The photodetector device according to claim 1, wherein said first region is surrounded by said groove portion.

3. The photodetection device according to claim 2, wherein the first region is an effective pixel region having pixels provided on the semiconductor substrate and outputting signals generated by photoelectric conversion in the pixels, and the second region is an ineffective pixel region that does not output signals generated by photoelectric conversion.

4. The photodetector device of claim 1, wherein a side surface of the groove portion has a first side surface provided on the semiconductor substrate and a second side surface provided on the organic insulating film, and the second side surface is recessed from the first side surface in a direction in which the width of the groove portion increases.

5. The photodetector according to claim 1, further comprising an insulating film made of a light-transmitting material provided between said first surface of said semiconductor substrate and said organic insulating film.

6. The photodetector according to claim 5, wherein the groove portion is provided in the organic insulating film, the insulating film and the semiconductor substrate, and the side surface of the groove portion has a first side surface provided on the semiconductor substrate, a second side surface provided on the organic insulating film and a third side surface provided on the insulating film, and the second side surface is recessed from the third side surface in a direction in which the width of the groove portion increases.

7. The photodetector device according to claim 1, wherein the organic insulating film comprises: a first organic insulating film; and a second organic insulating film provided on the first organic insulating film.

8. The photodetector according to claim 7, further comprising a color filter provided on the first surface side of the semiconductor substrate, the color filter being located between the first organic insulating film and the second organic insulating film.

9. The light detection device according to claim 1, further comprising a lens body provided on said first inorganic insulating film.

10. A semiconductor device comprising: a semiconductor substrate; an organic insulating film made of an organic material provided on a first surface side of the semiconductor substrate; a groove portion provided on the organic insulating film and the semiconductor substrate, the groove portion being the bottom surface of the semiconductor substrate; a first inorganic insulating film made of an inorganic material provided on the first surface side of the semiconductor substrate, covering the organic insulating film and filling the groove portion; and a second inorganic insulating film made of an inorganic material provided on the first inorganic insulating film, wherein the semiconductor substrate has, on the first surface side, a first region located on one side of the groove portion and a second region located on the other side of the groove portion, and a surface of the first inorganic insulating film is flat at least above the groove portion.

11. A method for manufacturing a photodetector, comprising the steps of: forming an organic insulating film made of a light-transmitting organic material on a first surface side of a semiconductor substrate; etching the organic insulating film and the semiconductor substrate to form a groove in the organic insulating film and the semiconductor substrate with the semiconductor substrate as a bottom surface; forming a first inorganic insulating film made of a light-transmitting inorganic material on the first surface side of the semiconductor substrate to cover the organic insulating film and fill the groove; forming a planarizing film on the first inorganic insulating film to planarize the surface on the first surface side of the semiconductor substrate; etching back the planarizing film and the first inorganic insulating film to planarize the surface of the first inorganic insulating film at least above the groove; and forming a second inorganic insulating film made of a light-transmitting inorganic material on the planarized surface of the first inorganic insulating film.

Images