JP2023133136A - Photoelectric conversion device, apparatus and substrate - Google Patents

Abstract

To improve the optical characteristics of a photoelectric conversion device.SOLUTION: A photoelectric conversion device comprises: a semiconductor layer that has a front face and a rear face, and is provided with a plurality of photoelectric conversion parts between the front face and the rear face; a wiring structure that is arranged on the side of the front face of the semiconductor layer; a first insulating film that is arranged on the side of the rear face of the semiconductor layer; a light shielding film that is arranged between the first insulating film and the rear face; a first separation part that is arranged between two photoelectric conversion parts of the plurality of photoelectric conversion parts; a second separation part that is arranged between another two photoelectric conversion parts of the plurality of photoelectric conversion parts, and has a smaller width than the first separation part; a first gap that is arranged inside the first separation part; a first light shielding wall that is arranged inside the first insulating film to overlap the first separation part; and a second light shielding wall that is arranged inside the first insulating film to overlap the second separation part. An end on the side of the rear face of the first light shielding wall is in contact with the light shielding film. The distance between an end on the side of the rear face of the light shielding film and the rear face is larger than the distance between an end on the side of the rear face of the second light shielding wall and the rear face.SELECTED DRAWING: Figure 3

Description

The present technology relates to a photoelectric conversion device, equipment, and substrate.

In a back-illuminated photoelectric conversion device, crosstalk between pixels can be suppressed by forming a groove-shaped separation part on the back side of the semiconductor layer or placing a light shielding member on the back side of the semiconductor layer. I can do it. Patent Document 1 discloses a back-illuminated photoelectric conversion device including a groove-shaped separation portion formed on the back side of a semiconductor layer, a light-shielding wall and a light-shielding film on the backside of the semiconductor layer, and a lower end of the light-shielding wall and a light-shielding film. A structure is disclosed in which the distance to the separation part is smaller than the distance between the lower end of the light shielding film and the separation part.

JP 2021-170585 Publication

In a back-illuminated photoelectric conversion device, in order to suppress crosstalk between adjacent pixels, a groove-shaped separation section placed on the back side of the semiconductor layer and a light shielding wall provided on the back side of the semiconductor layer are combined. It is necessary to reduce the distance. However, since there may be gaps in the isolation part that occur when filling the trench with an insulating film, if the lower end of the light-shielding wall is too close to the isolation part, the gaps in the isolation part will be exposed when manufacturing the photoelectric conversion device. It is possible. This is not preferable because it may affect the contamination of the manufacturing equipment when manufacturing the photoelectric conversion device. Patent Document 1 discloses a structure in which a lower end of a light shielding wall disposed above the separation section is close to the separation section. In this structure, crosstalk is effectively suppressed because the distance between the separation part and the light shielding wall is small. However, the lower end of the light shielding wall and the gap within the separation section may come into contact with each other. Therefore, an object of the present invention is to provide a photoelectric conversion device in which crosstalk and contamination during the manufacturing process are suppressed.

One aspect of the present invention provides a semiconductor layer having a front surface and a back surface, and a plurality of photoelectric conversion units provided between the front surface and the back surface, and wiring arranged on the front surface side of the semiconductor layer. a first insulating film disposed on the back surface side of the semiconductor layer; a light shielding film disposed between the first insulating film and the back surface; and two of the plurality of photoelectric conversion units. a first separation section disposed between two photoelectric conversion sections and another two of the plurality of photoelectric conversion sections, and a width in a first direction parallel to the back surface; is smaller than the first separating part, a first gap arranged inside the first separating part, and the first separating part so as to overlap with the first separating part in a plan view of the back surface side. a first light-shielding wall disposed inside one insulating film, and a second light-shielding wall disposed inside the first insulating film so as to overlap with the second separation part in a plan view of the back surface side; A photoelectric conversion device comprising: an end on the back side of the first light shielding wall is in contact with the light shielding film, and a distance between the end on the back side of the light shielding film and the back surface is , is larger than the distance between the back surface side end of the second light shielding wall and the back surface.

According to the present invention, it is possible to provide a photoelectric conversion device in which crosstalk and contamination during the manufacturing process are suppressed.

Schematic diagram explaining the configuration of a photoelectric conversion device Schematic diagram explaining the configuration of a photoelectric conversion device Schematic diagram explaining the configuration of the photoelectric conversion device of the first embodiment Schematic diagram illustrating the manufacturing method of the photoelectric conversion device shown in FIG. 3 Schematic diagram illustrating the manufacturing method of the photoelectric conversion device shown in FIG. 3 Schematic diagram illustrating the manufacturing method of the photoelectric conversion device shown in FIG. 3 Schematic diagram illustrating the configuration of a photoelectric conversion device according to the second embodiment Schematic diagram illustrating the configuration of the device of the third embodiment

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the claimed invention. Although a plurality of features are described in the embodiments, not all of these features are essential to the invention, and the plurality of features may be arbitrarily combined. Furthermore, in the accompanying drawings, the same or similar components are designated by the same reference numerals, and redundant description will be omitted. Further, in each embodiment described below, a CMOS sensor will be mainly described as an example of a photoelectric conversion device. However, each embodiment is not limited to CMOS sensors, and can be applied to other examples of photoelectric conversion devices. For example, there are CCDs, imaging devices, distance measuring devices (devices such as focus detection and distance measurement using TOF (Time of Flight)), photometry devices (devices such as measuring the amount of incident light), and the like.

In this specification, terms indicating specific directions and positions (for example, "upper", "lower", "right", "left", and other terms including these terms) are used as necessary. These terms are used to facilitate understanding of the embodiments with reference to the drawings, and the technical scope of the present invention is not limited by the meanings of these terms.

In this specification, a "plane" refers to a plane in a direction parallel to the main surface of the substrate. The principal surface of a substrate refers to the light incident surface of the substrate containing a photoelectric conversion element, the surface on which multiple analog-to-digital conversion circuits (ADCs) are repeatedly arranged, or the bonding surface between substrates in a stacked photoelectric conversion device. It can be. Moreover, "planar view" refers to viewing from a direction perpendicular to the main surface of the substrate. Furthermore, "cross section" refers to a plane in a direction perpendicular to the main surface of the substrate. Moreover, "cross-sectional view" refers to viewing from a direction parallel to the main surface of the substrate.

FIG. 1A is a schematic diagram of a back-illuminated photoelectric conversion device 10. The photoelectric conversion device 10 includes a light-receiving pixel region 11, a light-shielding pixel region 12, and a peripheral region 13. In the light-receiving pixel region 11 and the light-shielding pixel region 12, unit pixels including photoelectric conversion elements are two-dimensionally arranged in m rows and n columns. The peripheral region 13 is provided with pads or openings for pads to be connected to circuit elements or the outside, as necessary. Note that, as shown in FIG. 2, the back-illuminated photoelectric conversion device 10 may have a laminated structure in which the sensor substrate 21 and the circuit board 31 are each provided with a bonding surface 41 and are bonded to each other by their bonding surfaces. In this laminated structure, a pixel region 22 is arranged on the sensor substrate 21, and a circuit region 32 for processing a signal detected in the pixel region 22 is arranged on the circuit board 31.

FIG. 1(b) is a schematic cross-sectional view of the photoelectric conversion device 10 taken along line A-A' in FIG. 1(a). The photoelectric conversion device 10 includes a support substrate 20, a wiring structure 30, a semiconductor layer 40, and a back surface structure 50. The semiconductor layer 40 has a front surface 401 on the wiring structure 30 side and a back surface 402 on the incident light side. Note that although one photoelectric conversion section is illustrated in the figure, one pixel may include a plurality of photoelectric conversion sections.

In the semiconductor layer 40, a plurality of photoelectric conversion units 403 are provided between the front surface 401 and the back surface 402. The material of the semiconductor layer may be, for example, single crystal silicon or a compound semiconductor.

In the semiconductor layer 40, a separation portion 404 formed by a groove continuous from the back surface 402 in the depth direction of the semiconductor layer 40 is arranged. The separation unit 404 is arranged between the plurality of photoelectric conversion units 403 and has the role of reducing crosstalk between adjacent pixels. The material of the isolation section 404 is typically an insulating film such as silicon nitride or silicon oxide, but may also be a metal film. There may be a void 405 in the separation part 404 that is created when the separation part 404 is embedded. Since the gap 405 reflects light incident on adjacent pixels, optical crosstalk can be suppressed. Note that there may be cases where the void 405 does not exist.

The back surface structure 50 will be explained. A first insulating film 506 is disposed on the back surface 402 of the semiconductor layer 40. The first insulating film 506 may have, for example, a three-layer structure of silicon oxynitride, silicon nitride, and silicon oxynitride, or silicon oxide.

A light shielding film 502 and a second insulating film 501 are arranged between the first insulating film 506 and the back surface 402. Further, the second insulating film 501 is disposed between the light shielding film 502 and the back surface 402. The light-shielding film 502 is disposed on the light-shielding pixel region 12 and suppresses light rays from entering the photoelectric conversion unit 403 within the light-shielding pixel region 12 . The light shielding film 502 may be a metal film containing tungsten or aluminum. The second insulating film 501 may be made of silicon oxide, for example.

A third insulating film 507 is arranged on the first insulating film 506. The third insulating film 507 may be silicon oxide. Furthermore, a color filter 504 and a microlens 505 are provided on the third insulating film 507.

A light shielding wall 503 is disposed within the first insulating film 506, the second insulating film 501, and the third insulating film 507. The light shielding wall 503 is arranged so as to overlap the separation part 404 in a plan view on the back surface 402 side. The light shielding wall 503 may be a metal film containing tungsten. When light enters the photoelectric conversion device 10, the light is reflected by the light shielding wall 503, so that optical crosstalk to adjacent pixels can be suppressed. However, when a light beam with a large incident angle enters, the incident light passes through the gap between the lower end of the light shielding wall 503 (the end on the back surface 402 side) and the upper end of the separating section 404 (the end on the back surface 402 side), and the incident light reaches the adjacent pixel. Optical crosstalk due to irradiation may occur.

In order to suppress the above problem, it is preferable to reduce the distance D between the lower end of the light shielding wall 503 and the upper end of the separating section 404. However, since a void 405 may exist inside the separating portion 404, if the distance D is small, the lower end of the light shielding wall 503 and the upper end of the void 405 (end on the back surface 402 side) may come into contact due to manufacturing variations. A possibility arises. This is undesirable because it may cause problems such as contamination of manufacturing equipment.

The structure on the surface 401 side will be explained. A transistor (not shown) is provided on the surface of the semiconductor layer 40. A wiring structure 30 is arranged below the transistor. The wiring structure 30 has a multilayer wiring structure including a plurality of wiring structures. A support substrate 20 is provided below the wiring structure 30. The support substrate 20 mechanically supports the wiring structure 30, the semiconductor layer 40, and the back surface structure 50.

<First embodiment>
The first embodiment will be described using FIG. 3. FIG. 3A is a plan view including the photoelectric conversion unit 403 for six pixels. FIG. 3(b) is a cross-sectional view taken along line BB' in FIG. 3(a). Note that the direction indicated by line BB' in FIG. 3(a) is the first direction in the first embodiment. The first direction is parallel to the back surface 402. Further, in the first direction, the first light shielding film 502a is arranged between the first insulating films 506. As can be understood from FIG. 3(a), the light shielding wall 503 and the separation section 404 have a lattice shape, and the light rays that enter through the openings of the light shielding wall 503 and the separation section 404 are irradiated onto the photoelectric conversion section 403. This causes photoelectric conversion. Further, the light shielding wall 503 is arranged so as to overlap with the separation part 404 when viewed from above on the back surface 402 side. Note that the width of the separation part 404 may be different within the pixel region, and the larger the width of the separation part 404, the more the upper end of the gap 405 can extend upward.

As shown in FIG. 3B, in this embodiment, the width of the first separation section 404a in the first direction is larger than the width of the second separation section 404b in the first direction. Further, in the example shown in this embodiment, a first gap 405a is arranged inside the first separation part 404a, and a second gap 405b smaller than the first gap is arranged inside the second separation part 404b. Further, the upper end of the first gap 405a is located closer to the first insulating film 506 than the back surface 402, and the upper end of the second void 405b is located closer to the wiring structure 30 than the back surface 402. Further, the first light shielding wall 503a is arranged inside the first insulating film 506 so as to overlap the first separation part 404a in a plan view on the back surface 402 side. Further, the second light-shielding wall 503b is arranged inside the first insulating film 506 so as to overlap the second separating portion 404b when viewed in plan on the back surface 402 side. Furthermore, a first light-shielding film 502a is provided at the lower part of the first light-shielding wall 503a located on the first separation part 404a so as to be in contact with the lower end of the first light-shielding wall 503a. On the other hand, the second light-shielding wall 503b disposed above the second isolation part 404b has a lower end penetrating the first insulating film 506 and extending into the second insulating film 501. In other words, the distance between the end of the first light shielding wall 503a on the back surface 402 side and the back surface 402 is larger than the distance between the end of the first light shielding film 502a on the back surface 402 side and the back surface 402. . Furthermore, the distance between the end of the first light shielding film 502a on the back surface 402 side and the back surface 402 is larger than the distance between the end of the second light shielding wall 503b on the back surface 402 side and the back surface 402. .

The first light shielding film 502a functions as an etching stopper when forming the first light shielding wall 503a, and prevents the lower end of the first light shielding wall 503a from coming into contact with the first gap 405a inside the first separation part 404a. This simultaneously reduces optical crosstalk through the lower part of the second light shielding wall 503b and suppresses contact between the lower end of the first light shielding wall 503a and the first gap 405a inside the first separation part 404a. There is. In addition, in order for the first light shielding film 502a to effectively function as an etching stopper when forming the first light shielding wall 503a, the width of the first light shielding film 502a in the first direction must be set such that the width of the first light shielding film 502a in the first direction is It is preferably larger than the width. Although FIG. 3B shows an example in which the upper end of the first gap 405a is above the back surface 402, the present invention is not limited to this example. Furthermore, there may be an example in which the second void 405b does not exist.

An example of a method for manufacturing the photoelectric conversion device 10 in this embodiment will be described below with reference to FIGS. 4 to 6.

In step A shown in FIG. 4A, a member including the wiring structure 30 and the semiconductor layer 40 is laminated on the support substrate 20. The semiconductor layer 40 is processed to have a desired thickness. The thickness of the semiconductor layer 40 is typically about 1 to 5 μm. The semiconductor layer 40 has a front surface 401 on the wiring structure 30 side and a back surface 402 on the incident light side, and a plurality of photoelectric conversion parts 403 are formed between the front surface 401 and the back surface 402.

In step B shown in FIG. 4B, a separation section 404 is formed inside the semiconductor layer 40. The width of the separation portion 404 may be different within the pixel region. In this embodiment, the width of the second separation section 404b in the first direction is smaller than the width of the first separation section 404a in the first direction. In addition, in FIG. 4B, the lower end (end on the front surface 401 side) of the separation part 404 is shown to be between the front surface 401 and the back surface 402, but the separation part 404 is arranged so as to penetrate through the semiconductor layer 40. 404 may be formed.

In step C shown in FIG. 4C, a dielectric layer (not shown), an antireflection film (not shown), and a second insulating film 501 are formed on the back surface 402 and the separation part 404. The dielectric layer can be, for example, aluminum oxide or hafnium oxide. The anti-reflective coating layer can be, for example, tantalum oxide. The second insulating film 501 may be silicon oxide or silicon nitride. Further, inside the first separation part 404a and the second separation part 404b, there may exist a first gap 405a and a second gap 405b, respectively, which are generated when the second insulating film 501 is embedded, but the second gap 405b does not exist. There may be cases where it does not. In this example, the upper end of the first gap 405a is located above the back surface 402 of the semiconductor layer 40, and the top end of the second void 405b is located below the back surface 402 of the semiconductor layer 40. That is, the upper end of the first gap 405a is located closer to the first insulating film 506 than the back surface 402, and the upper end of the second void 405b is located closer to the wiring structure 30 than the back surface 402 is.

In step D shown in FIG. 5A, a light shielding film 502 is formed on the second insulating film 501. The light-shielding film 502 is formed by forming a metal film on the second insulating film 501 and then etching it so that the light-shielding film 502 is left only at desired locations. In this embodiment, the first light-shielding film 502a is arranged on the first separation part 404a, and the second light-shielding film 502b is arranged on the light-shielding pixel region 12. The light shielding film 502 may be a metal film containing, for example, tungsten or aluminum.

In step E shown in FIG. 5B, a first insulating film 506 and a third insulating film 507 are formed on the second insulating film 501 and the light shielding film 502. The surface of the third insulating film 507 is planarized by polishing using a chemical mechanical polishing method after the film is formed. The first insulating film 506 may have, for example, a three-layer structure of silicon oxynitride, silicon nitride, and silicon oxynitride, or silicon oxide. Further, the third insulating film 507 may be silicon oxide.

In step F shown in FIG. 5C, a hole 508 for the light shielding wall 503 is formed in the first insulating film 506, the second insulating film 501, and the third insulating film 507. The lower end (end on the back surface 402 side) of the second hole 508b for the second light shielding wall 503b located on the second separation part 404b penetrates the first insulating film 506 and extends to the second insulating film 501. It is etched so that it is present. Further, the distance between the end of the first light shielding film 502a on the back surface 402 side and the back surface 402 is larger than the distance between the end of the second hole 508b on the back surface 402 side and the back surface 402. At this time, the first hole 508a for the first light shielding wall 503a located on the first separation part 404a is also etched at the same time. However, since the first light shielding film 502a functions as an etch stopper, the lower end (end on the back surface 402 side) of the first hole 508a is formed so as to be in contact with the first light shielding film 502a. If the first light shielding film 502a is not present below the first hole 508a, the lower end of the first hole 508a penetrates the first insulating film 506 and extends into the second insulating film 501. At this time, the upper end of the first gap 405a inside the first separation part 404a can extend upward from the back surface 402 of the semiconductor layer 40, so the lower end of the first hole 508a and the upper end of the first gap 405a are in contact with each other. obtain. In that case, the chemical solution, etching gas, etc. used when forming the light shielding wall 503 may remain in the gap 405 and contaminate the manufacturing equipment in subsequent steps. In this embodiment, by using the first light shielding film 502a as an etching stopper for the first hole 508a, this problem can be suppressed and the yield can be improved. Note that in order for the first light-shielding film 502a to effectively function as an etching stopper when forming the first light-shielding wall 503a, the width of the first light-shielding film 502a in the first direction must be the same as that of the first light-shielding wall 503a in the first direction. It is preferably larger than the width.

In step G shown in FIG. 6A, a light-shielding material film is formed inside the hole 508 for the light-shielding wall 503, and the excess portion is removed by chemical mechanical polishing to form the light-shielding wall 503. . The light shielding material film may be a metal film containing tungsten.

In step H shown in FIG. 6B, a color filter 504 is formed on the third insulating film 507, and a microlens 505 is formed on the color filter 504.

The photoelectric conversion device 10 according to this embodiment can be manufactured by the above manufacturing method including the etching step in which the first hole 508a and the second hole 508b are formed.

Note that in this embodiment, a mode in which one separation section 404 includes one void has been described, but the present invention is not limited to this example. For example, apart from the first gap 405a, another gap may be provided below the first gap 405a. Further, the second void 405b may not be provided. Moreover, another gap may be provided in the separating section 404 provided with the second gap 405b.

<Second embodiment>
A second embodiment will be described using FIG. 7. FIG. 7A is a plan view including the photoelectric conversion unit 403 for six pixels. 7(b) shows a cross-sectional view taken along the line CC' in FIG. 7(a), and FIG. 7(c) shows a cross-sectional view taken along the line DD' in FIG. 7(a). Note that the CC' line and the DD' line in FIG. 7(a) are in a parallel relationship, and the direction indicated by these lines is the first direction in the second embodiment. The first direction is parallel to the back surface 402. Here, for example, a portion where the light blocking walls 503 intersect is defined as a cross portion of the light blocking wall 503, and a location where the light blocking walls 503 do not intersect is defined as a line portion of the light blocking wall 503. Further, the cross portion and the line portion may be applied to other than the light shielding wall 503, for example, they may be applied to the separation portion 404. Note that the same components as in the first embodiment are denoted by the same reference numerals, and the description of these components may be omitted or simplified. Further, the configuration of the second embodiment can be manufactured by a manufacturing method similar to that described in the first embodiment.

As understood from FIGS. 7A and 7B, a second light shielding wall 503b and a second separating part 404b are arranged in the line portion of the light shielding wall 503 and the separation part 404, and the lower end of the second light shielding wall 503b penetrates the first insulating film 506 and extends into the second insulating film 501 . On the other hand, as shown in FIGS. 7(a) and 7(c), a first light-shielding wall 503a and a first separation part 404a are arranged at the cross section of the light-shielding wall 503 and the separation part 404, and at the bottom of the first light-shielding wall 503a. A first light shielding film 502a is arranged so as to be in contact with a first light shielding wall 503a. Further, the distance between the end of the first light shielding wall 503a on the back surface 402 side and the back surface 402 is larger than the distance between the end of the first light shielding film 502a on the back surface 402 side and the back surface 402. Furthermore, the distance between the end of the first light shielding film 502a on the back surface 402 side and the back surface 402 is larger than the distance between the end of the second light shielding wall 503b on the back surface 402 side and the back surface 402. . In addition, in this example, the first separation part 404a is formed by crossing the second separation parts 404b.

The width of the second separating portion 404b in the first direction is smaller than that of the first separating portion 404a. Therefore, the upper end of the second gap 405b arranged in the line part of the separating part 404 may be located lower than the upper end of the first gap 405a arranged in the cross part of the separating part 404. Therefore, in the line part of the separation part 404, the distance D between the lower end of the second light shielding wall 503b and the upper end of the second separation part 404b can be reduced without contacting the second gap 405b inside the second separation part 404b. On the other hand, at the cross section of the separation section 404, the lower end of the first light shielding wall 503a and the upper end of the first gap 405a may come into contact. However, in this embodiment, since the first light shielding film 502a is disposed on the cross portion of the separation section 404, it is possible to prevent the lower end of the first light shielding wall 503a from coming into contact with the first gap 405a.

In this embodiment, in the line part, crosstalk is reduced by reducing the distance D between the lower end of the second light shielding wall 503b and the upper end of the second separation part 404b, and in the cross part, the first light shielding wall 503a Contact between the lower end of the first gap 405a and the first gap 405a is suppressed.

In addition, in order for the first light shielding film 502a to effectively function as an etching stopper when forming the first light shielding wall 503a, the width of the first light shielding film 502a in the first direction must be set such that the width of the first light shielding film 502a in the first direction is It is preferably larger than the width. Although FIG. 7B shows an example in which the upper end of the first gap 405a is above the back surface 402, the present invention is not limited to this example. Furthermore, there may be an example in which the second void 405b does not exist.

<Third embodiment>
Embodiment 3 can be applied to any of Embodiments 1 and 2. FIG. 8A is a schematic diagram illustrating a device 9191 including the semiconductor device 930 of this embodiment. The photoelectric conversion device (imaging device) of each embodiment described above can be used for the semiconductor device 930. The device 9191 including the semiconductor device 930 will be described in detail. In addition to the semiconductor device 910, the semiconductor device 930 can include a package 920 that houses the semiconductor device 910. The package 920 can include a base body to which the semiconductor device 910 is fixed, and a lid body made of glass or the like that faces the semiconductor device 910. The package 920 can further include a bonding member such as a bonding wire or a bump that connects the terminal provided on the base and the terminal provided on the semiconductor device 910.

The device 9191 can include at least one of an optical device 940, a control device 950, a processing device 960, a display device 970, a storage device 980, and a mechanical device 990. Optical device 940 corresponds to semiconductor device 930. The optical device 940 is, for example, a lens, a shutter, or a mirror, and includes an optical system that guides light to the semiconductor device 930. Control device 950 controls semiconductor device 930. The control device 950 is, for example, a semiconductor device such as an ASIC.

Processing device 960 processes the signal output from semiconductor device 930. The processing device 960 is a semiconductor device such as a CPU or an ASIC for configuring an AFE (analog front end) or a DFE (digital front end). The display device 970 is an EL display device or a liquid crystal display device that displays information (image) obtained by the semiconductor device 930. The storage device 980 is a magnetic device or a semiconductor device that stores information (image) obtained by the semiconductor device 930. The storage device 980 is a volatile memory such as SRAM or DRAM, or a nonvolatile memory such as a flash memory or a hard disk drive.

Mechanical device 990 has a movable part or a propulsion part such as a motor or an engine. The device 9191 displays the signal output from the semiconductor device 930 on the display device 970 or transmits it to the outside using a communication device (not shown) included in the device 9191. For this reason, it is preferable that the device 9191 further includes a storage device 980 and a processing device 960, in addition to the storage circuit and arithmetic circuit included in the semiconductor device 930. Mechanical device 990 may be controlled based on a signal output from semiconductor device 930.

Further, the device 9191 is suitable for electronic devices such as information terminals (for example, smartphones and wearable terminals) and cameras (for example, interchangeable lens cameras, compact cameras, video cameras, and surveillance cameras) that have a shooting function. Mechanical device 990 in the camera can drive parts of optical device 940 for zooming, focusing, and shutter operation. Alternatively, the mechanical device 990 in the camera can move the semiconductor device 930 for anti-vibration operation.

Further, the device 9191 may be a transportation device such as a vehicle, a ship, or an aircraft. Mechanical device 990 in a transportation device can be used as a moving device. The device 9191 as a transport device is suitable for transporting the semiconductor device 930 or for assisting and/or automating driving (maneuvering) using a photographing function. A processing device 960 for assisting and/or automating driving (maneuvering) can perform processing for operating a mechanical device 990 as a mobile device based on information obtained by the semiconductor device 930. Alternatively, the device 9191 may be a medical device such as an endoscope, a measuring device such as a distance sensor, an analytical device such as an electron microscope, an office device such as a copying machine, or an industrial device such as a robot.

According to the embodiments described above, it is possible to obtain good pixel characteristics. Therefore, the value of the semiconductor device can be increased. Increasing value here includes at least one of the following: adding functionality, improving performance, improving characteristics, improving reliability, improving manufacturing yield, reducing environmental impact, reducing cost, downsizing, and reducing weight. Applicable.

Therefore, if the semiconductor device 930 according to this embodiment is used in the device 9191, the value of the device can also be improved. For example, by mounting the semiconductor device 930 on a transportation device, excellent performance can be obtained when photographing the exterior of the transportation device or measuring the external environment. Therefore, when manufacturing and selling transportation equipment, deciding to mount the semiconductor device according to this embodiment on the transportation equipment is advantageous in improving the performance of the transportation equipment itself. In particular, the semiconductor device 930 is suitable for transportation equipment that performs driving support and/or automatic operation of transportation equipment using information obtained by the semiconductor device.

Further, the photoelectric conversion system and moving body of this embodiment will be explained using FIGS. 8(b) and 8(c).

FIG. 8(a) shows an example of a photoelectric conversion system related to an on-vehicle camera. The photoelectric conversion system 8 includes a photoelectric conversion device 10. The photoelectric conversion device 10 is the photoelectric conversion device (imaging device) described in any of the above embodiments. The photoelectric conversion system 8 includes an image processing unit 101 that performs image processing on the plurality of image data acquired by the photoelectric conversion device 10, and a parallax (position of parallax images) from the plurality of image data acquired by the photoelectric conversion system 8. It has a parallax acquisition unit 102 that calculates phase difference). The photoelectric conversion system 8 also includes a distance acquisition unit 103 that calculates the distance to the object based on the calculated parallax, and a collision determination unit that determines whether there is a possibility of a collision based on the calculated distance. 104. Here, the parallax acquisition unit 102 and the distance acquisition unit 103 are examples of distance information acquisition means that acquires distance information to the target object. That is, distance information is information regarding parallax, defocus amount, distance to a target object, and the like. The collision determination unit 104 may determine the possibility of collision using any of these pieces of distance information. The distance information acquisition means may be realized by specially designed hardware or may be realized by a software module. Further, it may be realized by an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or a combination thereof.

The photoelectric conversion system 8 is connected to a vehicle information acquisition device 810, and can acquire vehicle information such as vehicle speed, yaw rate, and steering angle. Further, the photoelectric conversion system 8 is connected to a control ECU 820 that is a control device that outputs a control signal for generating a braking force to the vehicle based on the determination result of the collision determination unit 104. The photoelectric conversion system 8 is also connected to a warning device 830 that issues a warning to the driver based on the determination result of the collision determination unit 104. For example, if the collision determination unit 104 determines that there is a high possibility of a collision, the control ECU 820 performs vehicle control to avoid the collision and reduce damage by applying the brakes, releasing the accelerator, or suppressing engine output. The alarm device 830 warns the user by sounding an alarm such as a sound, displaying alarm information on a screen of a car navigation system, etc., or applying vibration to a seat belt or steering wheel.

In this embodiment, the photoelectric conversion system 8 images the surroundings of the vehicle, for example, the front or the rear. FIG. 8(c) shows a photoelectric conversion system for capturing an image in front of the vehicle (imaging range 850). Vehicle information acquisition device 810 sends instructions to photoelectric conversion system 8 or photoelectric conversion device 10 . With such a configuration, the accuracy of distance measurement can be further improved.

Above, we explained an example of control to avoid collisions with other vehicles, but it can also be applied to control to automatically drive while following other vehicles, control to automatically drive to avoid moving out of the lane, etc. . Furthermore, the photoelectric conversion system can be applied not only to vehicles such as own vehicles, but also to mobile objects (mobile devices) such as ships, aircraft, and industrial robots. In addition, the present invention can be applied not only to mobile objects but also to a wide range of devices that use object recognition, such as intelligent transportation systems (ITS).

The embodiments described above can be modified as appropriate without departing from the technical concept. Note that the disclosure content of this specification includes not only what is described in this specification, but also all matters that can be understood from this specification and the drawings attached to this specification. The disclosure herein also includes the complement of the concepts described herein. In other words, if the specification includes, for example, the statement "A is greater than B," even if the statement "A is not greater than B" is omitted, the specification still states "A is greater than B." It can be said that the company has disclosed that it is not large. This is because when it is stated that "A is larger than B", it is assumed that "A is not larger than B" is being considered.

Note that the disclosure of this embodiment includes the following configuration and method.

(Structure 1) A semiconductor layer having a front surface and a back surface, in which a plurality of photoelectric conversion units are provided between the front surface and the back surface, a wiring structure disposed on the front surface side of the semiconductor layer, a first insulating film disposed on the back surface side of the semiconductor layer; a light shielding film disposed between the first insulating film and the back surface; and two photoelectric conversion units of the plurality of photoelectric conversion units. and another two photoelectric conversion units of the plurality of photoelectric conversion units, and the width in the first direction parallel to the back surface is equal to or greater than the first separation unit. a second separation section smaller than the separation section; a first gap disposed inside the first separation section; a first light-shielding wall disposed inside the first insulating film, and a second light-shielding wall disposed inside the first insulating film so as to overlap the second separation part in a plan view of the back side. In the conversion device, an end of the first light-shielding wall on the back side is in contact with the light-shielding film, and a distance between the end of the back-side of the light-shielding film and the back surface is equal to 2. A photoelectric conversion device characterized in that the distance is greater than the distance between the end of the back surface of the second light-shielding wall and the back surface.

(Structure 2) The photoelectric conversion device according to Structure 1, wherein an end of the first gap on the back surface side is located closer to the first insulating film than the back surface.

(Structure 3) The structure according to structure 1 or 2, wherein an end of the second gap disposed inside the second separating section on the back surface side is located closer to the wiring structure than the back surface. Photoelectric conversion device.

(Structure 4) The photovoltaic device according to any one of Structures 1 to 3, wherein the first separation part is formed by crossing the second separation parts in a plan view of the back side. conversion device.

(Structure 5) Photoelectric conversion according to any one of Structures 1 to 4, wherein the width of the light shielding film in the first direction is larger than the width of the first light shielding wall in the first direction. Device.

(Structure 6) The photoelectric conversion device according to any one of Structures 1 to 5, wherein a second insulating film is disposed between the light shielding film and the back surface.

(Structure 7) The photoelectric conversion device according to any one of Structures 1 to 6, wherein an end portion of the second light shielding wall on the back surface side is disposed on the second insulating film.

(Structure 8) The first separation part and the second separation part are formed by grooves continuous from the back surface in the depth direction of the semiconductor, according to any one of Structures 1 to 7. Photoelectric conversion device.

(Structure 9) The photoelectric conversion device according to any one of Structures 1 to 8, wherein the light shielding film contains tungsten or aluminum, and the first light shielding wall and the second light shielding wall contain tungsten.

(Structure 10) A semiconductor layer having a front surface and a back surface, and a plurality of photoelectric conversion units provided between the front surface and the back surface, a wiring structure disposed on the front surface side of the semiconductor layer, a first insulating film disposed on the back surface side of the semiconductor layer; a light shielding film disposed between the first insulating film and the back surface; and two photoelectric conversion units of the plurality of photoelectric conversion units. and another two photoelectric conversion units of the plurality of photoelectric conversion units, and the width in the first direction parallel to the back surface is equal to or greater than the first separation unit. a second separation section smaller than the separation section; a first gap disposed inside the first separation section; a first light-shielding wall disposed inside the first insulating film, and a second light-shielding wall disposed inside the first insulating film so as to overlap the second separation section when viewed from above on the back surface side. The back end of the first light shielding wall is in contact with the light shielding film, and the distance between the back end of the light shielding film and the back surface is equal to the second light shielding wall. A substrate characterized in that the distance is greater than the distance between the end of the wall on the back surface side and the back surface.

(Structure 11) An end of the first gap is located closer to the first insulating film than the back surface, and an end of the second gap disposed inside the second separation part is located closer to the first insulating film than the back surface. 11. The substrate according to configuration 10, wherein the substrate is located on the side of the wiring structure.

(Structure 12) The substrate according to Structure 10 or 11, wherein the first separation part is formed by crossing the second separation parts in a plan view of the back surface side.

(Structure 13) The substrate according to any one of Structures 10 to 12, wherein the width of the light shielding film in the first direction is larger than the width of the first light shielding wall in the first direction.

(Structure 14) The board according to any one of Structures 10 to 13, comprising a surface to be bonded to a circuit board.

(Configuration 15) A device comprising the photoelectric conversion device according to any one of Configurations 1 to 9, including an optical device that guides light to the photoelectric conversion device, a control device that controls the photoelectric conversion device, and the photoelectric conversion device. A processing device that processes signals output from the device, a display device that displays information obtained by the photoelectric conversion device, a storage device that stores information obtained by the photoelectric conversion device, and a processing device that processes the information obtained by the photoelectric conversion device. A device further comprising at least one of the following: a mechanical device that operates based on the received information.

(Method 1) A semiconductor layer having a front surface and a back surface, in which a plurality of photoelectric conversion parts are provided between the front surface and the back surface, a wiring structure disposed on the front surface side of the semiconductor layer, a first insulating film disposed on the back surface side of the semiconductor layer; a light shielding film disposed between the first insulating film and the back surface; and two photoelectric conversion units of the plurality of photoelectric conversion units. and another two photoelectric conversion units of the plurality of photoelectric conversion units, and the width in the first direction parallel to the back surface is equal to or greater than the first separation unit. a second separation section smaller than the separation section; a first gap disposed inside the first separation section; a first hole disposed inside the first insulating film, and a second hole disposed inside the first insulating film so as to overlap the second separation section when viewed from above on the back surface side. The method for manufacturing a conversion device, wherein the back side end of the first hole is in contact with the light shielding film, and the distance between the back side end of the light shielding film and the back surface is A photovoltaic device comprising an etching step in which the first hole and the second hole are formed so as to be larger than the distance between the end of the second hole on the back side and the back surface. Method for manufacturing a conversion device.

(Method 2) A first light-shielding wall is formed by disposing metal in the first hole, and a second light-shielding wall is formed by disposing metal in the second hole. The method for manufacturing a photoelectric conversion device according to method 1.

(Method 3) An end of the first gap is located closer to the first insulating film than the back surface, and an end of the second gap disposed inside the second separation section is located closer to the first insulating film than the back surface. The method for manufacturing a photoelectric conversion device according to method 1 or 2, characterized in that the photoelectric conversion device is located on the side of a wiring structure.

(Method 4) The photovoltaic device according to any one of Methods 1 to 3, wherein the first separating portion is formed by crossing the second separating portions in a plan view of the back side. Method for manufacturing a conversion device.

(Method 5) Photoelectric conversion according to any one of Methods 1 to 4, wherein the width of the light shielding film in the first direction is larger than the width of the first light shielding wall in the first direction. Method of manufacturing the device.

(Method 6) A semiconductor layer having a front surface and a back surface, and a plurality of photoelectric conversion units provided between the front surface and the back surface, a wiring structure disposed on the front surface side of the semiconductor layer, a first insulating film disposed on the back surface side of the semiconductor layer; a light shielding film disposed between the first insulating film and the back surface; and two photoelectric conversion units of the plurality of photoelectric conversion units. and another two photoelectric conversion units of the plurality of photoelectric conversion units, and the width in the first direction parallel to the back surface is equal to or greater than the first separation unit. a second separation section smaller than the separation section; a first gap disposed inside the first separation section; a first hole disposed inside the first insulating film; and a second hole disposed inside the first insulating film so as to overlap the second separation section when viewed from above on the back side. In the manufacturing method, an end of the first hole on the back side is in contact with the light-shielding film, and a distance between the end of the back-side of the light-shielding film and the back surface is in contact with the second hole. manufacturing a substrate, comprising: an etching step in which the first hole and the second hole are formed so as to be larger than the distance between the end on the back side of the part and the back surface; Method.

(Method 7) A first light-shielding wall is formed by disposing metal in the first hole, and a second light-shielding wall is formed by disposing metal in the second hole. The method for manufacturing a substrate according to method 6.

(Method 8) An end of the first gap is located closer to the first insulating film than the back surface, and an end of the second gap disposed inside the second separation section is located closer to the first insulating film than the back surface. The method for manufacturing a substrate according to method 6 or 7, characterized in that the method is located on the side of a wiring structure.

(Method 9) The substrate according to any one of methods 6 to 8, wherein the first separation part is formed by crossing the second separation parts in a plan view of the back surface side. manufacturing method.

(Method 10) The substrate according to any one of Methods 6 to 9, wherein the width of the light shielding film in the first direction is larger than the width of the first light shielding wall in the first direction. Production method.

(Method 11) The method for manufacturing a board according to any one of Methods 6 to 10, characterized by comprising a surface to be bonded to a circuit board.

401 Front surface 402 Back surface 403 Photoelectric conversion section 40 Semiconductor layer 30 Wiring structure 501 Second insulating film 506 First insulating film 502a First light shielding film 502b Second light shielding film 404a First separation section 404b Second separation section 405a First gap 405b 2 gaps 503a first light shielding wall 503b second light shielding wall

Claims (26)

a semiconductor layer having a front surface and a back surface, and a plurality of photoelectric conversion parts provided between the front surface and the back surface;
a wiring structure arranged on the surface side of the semiconductor layer;
a first insulating film disposed on the back surface side of the semiconductor layer;
a light shielding film disposed between the first insulating film and the back surface;
a first separation section disposed between two photoelectric conversion sections of the plurality of photoelectric conversion sections;
a second separation section that is disposed between another two of the plurality of photoelectric conversion sections and has a width smaller than the first separation section in a first direction parallel to the back surface;
a first gap arranged inside the first separating section;
a first light-shielding wall disposed inside the first insulating film so as to overlap the first separation part in a plan view of the back side;
a second light-shielding wall disposed inside the first insulating film so as to overlap the second separation part in a plan view of the back side;
A photoelectric conversion device comprising:
The end of the first light-shielding wall on the back side is in contact with the light-shielding film,
The photoelectric conversion characterized in that the distance between the back side end of the light shielding film and the back surface is larger than the distance between the back side end of the second light shielding wall and the back surface. Device. 2. The photoelectric conversion device according to claim 1, wherein an end of the first gap on the back surface side is located closer to the first insulating film than the back surface. 2. The photoelectric conversion device according to claim 1, wherein an end of the second gap disposed inside the second separating section on the back surface side is located closer to the wiring structure than the back surface. 2. The photoelectric conversion device according to claim 1, wherein the first separating part is formed by crossing the second separating parts in a plan view of the back side. The photoelectric conversion device according to claim 1, wherein the width of the light shielding film in the first direction is larger than the width of the first light shielding wall in the first direction. The photoelectric conversion device according to claim 1, wherein a second insulating film is disposed between the light shielding film and the back surface. 7. The photoelectric conversion device according to claim 6, wherein an end portion of the second light shielding wall on the back surface side is disposed on the second insulating film. 2. The photoelectric conversion device according to claim 1, wherein the first separation part and the second separation part are formed by grooves continuous from the back surface in a depth direction of the semiconductor. 2. The photoelectric conversion device according to claim 1, wherein the light-shielding film contains tungsten or aluminum, and the first light-shielding wall and the second light-shielding wall contain tungsten. a semiconductor layer having a front surface and a back surface, and a plurality of photoelectric conversion parts provided between the front surface and the back surface;
a wiring structure arranged on the surface side of the semiconductor layer;
a first insulating film disposed on the back surface side of the semiconductor layer;
a light shielding film disposed between the first insulating film and the back surface;
a first separation section disposed between two photoelectric conversion sections of the plurality of photoelectric conversion sections;
a second separation section that is disposed between another two of the plurality of photoelectric conversion sections and has a width smaller than the first separation section in a first direction parallel to the back surface;
a first gap arranged inside the first separating section;
a first light-shielding wall disposed inside the first insulating film so as to overlap the first separation part in a plan view of the back side;
a second light-shielding wall disposed inside the first insulating film so as to overlap the second separation part in a plan view of the back side;
A substrate comprising:
The end of the first light-shielding wall on the back side is in contact with the light-shielding film,
A substrate characterized in that a distance between the back side end of the light shielding film and the back surface is larger than a distance between the back side end of the second light shielding wall and the back surface. An end of the first gap on the back surface side is located closer to the first insulating film than the back surface, and an end of the second gap disposed inside the second separation section on the back surface side is located closer to the first insulating film than the back surface. 11. The substrate according to claim 10, wherein the substrate is located closer to the wiring structure than the back surface. 11. The substrate according to claim 10, wherein the first separating part is formed by crossing the second separating parts in a plan view of the back side. 11. The substrate according to claim 10, wherein the width of the light shielding film in the first direction is larger than the width of the first light shielding wall in the first direction. 11. The board according to claim 10, further comprising a surface to be bonded to a circuit board. a semiconductor layer having a front surface and a back surface, and a plurality of photoelectric conversion parts provided between the front surface and the back surface;
a wiring structure arranged on the surface side of the semiconductor layer;
a first insulating film disposed on the back surface side of the semiconductor layer;
a light shielding film disposed between the first insulating film and the back surface;
a first separation section disposed between two photoelectric conversion sections of the plurality of photoelectric conversion sections;
a second separation section that is disposed between another two of the plurality of photoelectric conversion sections and has a width smaller than the first separation section in a first direction parallel to the back surface;
a first gap arranged inside the first separating section;
a first hole portion disposed inside the first insulating film so as to overlap the first separation portion in a plan view of the back surface side;
a second hole portion disposed inside the first insulating film so as to overlap the second separation portion in a plan view of the back surface side;
A method for manufacturing a photoelectric conversion device comprising:
The end of the first hole on the back side is in contact with the light shielding film, and the distance between the end of the back side of the light shielding film and the back surface is the end of the second hole on the back side. A method for manufacturing a photoelectric conversion device, comprising an etching step in which the first hole and the second hole are formed so as to be larger than the distance between the first hole and the back surface. 15. A first light-shielding wall is formed by disposing metal in the first hole, and a second light-shielding wall is formed by disposing metal in the second hole. A method for manufacturing a photoelectric conversion device according to. An end of the first gap on the back surface side is located closer to the first insulating film than the back surface, and an end of the second gap disposed inside the second separation section on the back surface side is located closer to the first insulating film than the back surface. 16. The method for manufacturing a photoelectric conversion device according to claim 15, wherein the photoelectric conversion device is located closer to the wiring structure than the back surface. 16. The method of manufacturing a photoelectric conversion device according to claim 15, wherein the first separating part is formed by crossing the second separating parts in a plan view of the back side. 17. The method of manufacturing a photoelectric conversion device according to claim 16, wherein the width of the light shielding film in the first direction is larger than the width of the first light shielding wall in the first direction. a semiconductor layer having a front surface and a back surface, and a plurality of photoelectric conversion parts provided between the front surface and the back surface;
a wiring structure arranged on the surface side of the semiconductor layer;
a first insulating film disposed on the back surface side of the semiconductor layer;
a light shielding film disposed between the first insulating film and the back surface;
a first separation section disposed between two photoelectric conversion sections of the plurality of photoelectric conversion sections;
a second separation section that is disposed between another two of the plurality of photoelectric conversion sections and has a width smaller than the first separation section in a first direction parallel to the back surface;
a first gap arranged inside the first separating section;
a first hole portion disposed inside the first insulating film so as to overlap the first separation portion in a plan view of the back surface side;
a second hole portion disposed inside the first insulating film so as to overlap the second separation portion in a plan view of the back surface side;
A method of manufacturing a substrate comprising:
The end of the first hole on the back side is in contact with the light shielding film, and the distance between the end of the back side of the light shielding film and the back surface is the end of the second hole on the back side. A method of manufacturing a substrate, comprising: an etching step in which the first hole and the second hole are formed so as to be larger than the distance between the first hole and the back surface. 20. A first light-shielding wall is formed by disposing metal in the first hole, and a second light-shielding wall is formed by disposing metal in the second hole. The method for manufacturing the substrate described in . An end of the first gap on the back surface side is located closer to the first insulating film than the back surface, and an end of the second gap disposed inside the second separation section on the back surface side is located closer to the first insulating film than the back surface. 21. The method of manufacturing a substrate according to claim 20, wherein the substrate is located closer to the wiring structure than the back surface. 21. The method of manufacturing a substrate according to claim 20, wherein the first separating part is formed by crossing the second separating parts in a plan view of the back side. 22. The method of manufacturing a substrate according to claim 21, wherein the width of the light shielding film in the first direction is larger than the width of the first light shielding wall in the first direction. 21. The method of manufacturing a board according to claim 20, further comprising a surface to be bonded to a circuit board. A device comprising the photoelectric conversion device according to any one of claims 1 to 9,
an optical device that guides light to the photoelectric conversion device;
a control device that controls the photoelectric conversion device;
a processing device that processes the signal output from the photoelectric conversion device;
a display device that displays information obtained by the photoelectric conversion device;
a storage device that stores information obtained by the photoelectric conversion device; and
a mechanical device that operates based on information obtained by the photoelectric conversion device;
A device further comprising at least one of the following.

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