Distance measuring device and manufacturing method thereof

Abstract

[Problem] To enable miniaturization and cost reduction while performing ranging processing with low power consumption. [Solution] A distance measurement device measures the distance to an object on the basis of a reflected light signal received by a light receiving unit, said reflected light signal being generated when an optical pulse signal emitted from a light emitting unit is reflected by the object. The distance measuring device includes: a first substrate formed of a group IV material on which a light receiving portion and a light emitting portion are integrally arranged; and a second substrate laminated on the first substrate, and on which a readout circuit for reading out the light reception signal received by the light receiving portion is arranged.

Description

Technical Field

[0001] The present disclosure relates to a distance measuring device and a manufacturing method thereof. Background Art

[0002] A ToF (Time of Flight) LiDAR (Light Detection and Ranging) device is a key device in automated driving technology, and research and development are being actively conducted to perform high-precision distance measurement. The ToF LiDAR device measures the distance to the object by illuminating the object with a light pulse signal emitted from a light emitting portion and receiving a reflected light pulse signal reflected by the object with a light receiving portion (see Patent Document 1).

[0003] [Citation List]

[0004] [Patent Document]

[0005] [Patent Document 1]

[0006] JP 2021-27358A Summary of the invention

[0007] [Technical issues]

[0008] Since the light emitting part and the light receiving part have different structures, the light emitting part and the light receiving part are usually manufactured separately and mounted on a common supporting substrate. Therefore, LiDAR is time-consuming to manufacture, difficult to miniaturize, and cannot reduce power consumption.

[0009] Therefore, the present disclosure provides a distance measurement device capable of being miniaturized and reduced in cost and capable of performing a distance measurement process with low power consumption, and a method of manufacturing the same.

[0010] [Solution to the problem]

[0011] In order to solve the above problems, the present disclosure provides a distance measuring device, which measures the distance to an object based on a reflected light signal received by a light receiving part, wherein the reflected light signal is generated when a light pulse signal emitted from a light emitting part is reflected by the object, and the distance measuring device includes: a first substrate formed of a Group IV material, on which a light receiving part and a light emitting part are integrally arranged; and a second substrate laminated on the first substrate, and a readout circuit for reading out the light receiving signal received by the light receiving part is arranged on the second substrate.

[0012] The light receiving portion and the light emitting portion may be integrally arranged on the first substrate.

[0013] The first substrate may be a silicon substrate.

[0014] The light emitting portion may include a compound semiconductor material or a mixed crystal of a compound semiconductor material.

[0015] The buffer layer may be disposed on the first substrate and formed of a Group IV material different from the material of the first substrate, the light emitting portion being disposed on the buffer layer, and the material of the buffer layer having a lattice spacing closer to that of the light emitting portion than that of the material of the first substrate.

[0016] The light receiving section may include a photodiode, an avalanche photodiode, or a SPAD (Single Photon Avalanche Diode).

[0017] When viewed in a plan view in a normal direction of a substrate surface of the first substrate, at least a portion of the light receiving portion may overlap with the readout circuit.

[0018] The light emitting portion may be arranged on the first substrate by selective epitaxial growth.

[0019] The distance measuring device may include a light shielding member including a metal material disposed between an arrangement region of the light receiving portion on the first substrate and an arrangement region of the light emitting portion on the first substrate.

[0020] The light emitting portion may be arranged along a surface of the first substrate opposite to a surface facing the second substrate.

[0021] The light emitting portion may be disposed inside the first substrate.

[0022] The second substrate may include a driving circuit that supplies a driving voltage to the light emitting portion.

[0023] When viewed in a plan view in a normal direction of a substrate surface of the first substrate, at least a portion of the light emitting portion may overlap with the driving circuit.

[0024] The distance measuring device may also include a joining member extending in the depth direction of the first substrate to connect the light-emitting portion with the driving circuit, and when observed from a plan view in the normal direction of the substrate surface of the first substrate, at least a portion of the joining member may be arranged in an area overlapping with the light-emitting portion.

[0025] The distance measuring device may also include a joining member extending in the depth direction of the first substrate to connect the light-emitting portion with the driving circuit, and when observed in a plan view in the normal direction of the substrate surface of the first substrate, at least a portion of the joining member may be arranged in an area that does not overlap with the light-emitting portion.

[0026] The drive circuit may be arranged in a region that does not overlap with the light emitting portion when viewed in a plan view in a normal direction of a substrate surface of the first substrate.

[0027] A partial circuit included in the readout circuit can be arranged on the first substrate, the light receiving unit can have a plurality of photoelectric conversion elements arranged in a two-dimensional direction, each photoelectric conversion element receives light, and the partial circuit can have a plurality of pixel circuits connected to each of the plurality of photoelectric conversion elements.

[0028] The first substrate may have a light emitting portion and a light receiving portion arranged adjacent to each other, each light emitting portion may have a plurality of light emitting elements arranged close to each other, and each light receiving portion may have a plurality of photoelectric conversion elements arranged close to each other.

[0029] The light emitting portion may have a plurality of light emitting elements, and the light receiving portion may have a plurality of light receiving elements arranged between the plurality of light emitting elements, arranged to surround the plurality of light emitting elements, or arranged to be surrounded by the plurality of light emitting elements.

[0030] The light emitting portion may be a VCSEL (Vertical Cavity Surface Emitting Laser).

[0031] The present disclosure also provides a method for manufacturing a distance measuring device, comprising: forming a light receiving portion in a first region of a first substrate formed of a Group IV material; forming a buffer layer formed of a Group IV material different from the material of the first substrate on an upper surface of a second region of the first substrate; forming a light emitting portion formed of a compound semiconductor material on the buffer layer by selective epitaxial growth; and bonding a second substrate to the first substrate, the second substrate having a readout circuit and a drive circuit, the readout circuit being used to read out a light receiving signal received by the light receiving portion, and the drive circuit being used to supply a drive voltage to the light emitting portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a cross-sectional view showing a cross-sectional structure of the distance measuring device according to the first embodiment.

[0033] Figure 2 yes Figure 1 A plan view of a light receiving portion.

[0034] Figure 3A : is a cross-sectional view showing a manufacturing process of the distance measuring device according to the first embodiment.

[0035] Figure 3B : is a plan view showing a manufacturing process of the distance measuring device according to the first embodiment.

[0036] Figure 3C It is shown Figure 3A A cross-sectional view of the process followed.

[0037] Figure 3D It is shown Figure 3B Floor plan of the after process.

[0038] Figure 3E It is shown Figure 3C A cross-sectional view of the process followed.

[0039] Figure 3F It is shown Figure 3D Floor plan of the after process.

[0040] Figure 3G It is shown Figure 3E A cross-sectional view of the process followed.

[0041] Figure 3H It is shown Figure 3F Floor plan of the after process.

[0042] Fig. 3I It is shown Figure 3G A cross-sectional view of the process followed.

[0043] Figure 3J It is shown Figure 3H Floor plan of the after process.

[0044] Figure 3K It is shown Fig. 3I A cross-sectional view of the process followed.

[0045] Figure 3L It is shown Figure 3K A cross-sectional view of the process followed.

[0046] Figure 3M It is shown Figure 3L A cross-sectional view of the process followed.

[0047] Figure 4 is a cross-sectional view of a distance measuring device according to a second embodiment.

[0048] Figure 5 is a cross-sectional view of a distance measuring device according to a third embodiment.

[0049] Figure 6 is a cross-sectional view of a distance measuring device according to a fourth embodiment.

[0050] Figure 7 is a cross-sectional view of a distance measuring device according to a fifth embodiment.

[0051] Figure 8 is a plan view of the light receiving portion of the first substrate.

[0052] Fig. 9 is a plan view of a distance measuring device according to a seventh embodiment.

[0053] Fig.10is a plan view of a distance measurement device according to a first modification example of the seventh embodiment.

[0054] Fig.11 is a plan view of a distance measurement device according to a second modification example of the seventh embodiment.

[0055] Fig.12 is a block diagram of a distance measuring device according to the first to seventh embodiments.

[0056] Fig.13 is a block diagram showing an example of the overall configuration of a vehicle control system.

[0057] Fig.14 2 is a schematic diagram showing an example of the installation positions of the vehicle exterior information detection section and the imaging section. DETAILED DESCRIPTION

[0058] Embodiments of the distance measuring device and the method for manufacturing the same will be described below with reference to the accompanying drawings. Although the following will mainly describe the main components of the distance measuring device and the method for manufacturing the same, the distance measuring device and the method for manufacturing the same may have components and functions that are not shown or described. The following description does not exclude components or functions that are not shown or described.

[0059] (First Embodiment)

[0060] Figure 1 is a cross-sectional view showing a cross-sectional structure of the distance measurement device 1 according to the first embodiment. Figure 1 The distance measuring device 1 in the embodiment measures the distance to the object based on a reflected light signal received by the light receiving section 3 , the reflected light signal being generated when the light pulse signal emitted from the light emitting section 2 is reflected by the object.

[0061] In the distance measuring device 1 according to the first embodiment, the light emitting part 2 and the light receiving part 3 are integrally formed on the same substrate. Integrally means that the light emitting part 2 and the light receiving part 3 are formed on the same substrate by a semiconductor process. The light emitting part 2 and the light receiving part 3 may be formed of the same or different materials.

[0062] Figure 1 The distance measuring device 1 in FIG. 1 has a structure in which a first substrate 4 is bonded to a second substrate 5. When the first substrate 4 is bonded to the second substrate 5, various bonding forms such as Cu-Cu bonding, a bump, and a through hole can be applied.

[0063] The first substrate 4 is formed of a Group IV material. For example, the first substrate 4 is formed of silicon (Si) or germanium (Ge). As described above, in the present embodiment, it is assumed that the light emitting portion 2 and the light receiving portion 3 are integrally formed on the first substrate 4, and the material of the first substrate 4 needs to be selected in consideration of the constituent materials of the light emitting element and the photoelectric conversion element 3a.

[0064] The light emitting section 2 is, for example, a semiconductor laser formed of a compound semiconductor material or a mixed crystal of a compound semiconductor material. The compound semiconductor material of the light emitting section 2 is, for example, a III-V group element, specifically, GaAs, InGaAs, InAlGaAs, GaAsSb, GaP, InP, InGaAsP, GaInNAs, etc.

[0065] The light emitting section 2 may be a surface light emitting element having a plurality of light emitting elements. A representative example of the light emitting section 2 is a VCSEL (Vertical Cavity Surface Emitting Laser). The VCSEL has a plurality of light emitting elements arranged in one or two dimensions and can emit surface light.

[0066] The light emitting portion 2 is formed, for example, by selective epitaxial growth on the first substrate 4. More specifically, for example, Figure 1 As shown in , the light emitting portion 2 is formed by selective epitaxial growth on the surface of the first substrate 4 opposite to the surface facing the second substrate 5 .

[0067] The light receiving portion 3 is formed in a diffusion region formed by injecting impurities into a portion of the first substrate 4. Alternatively, the light receiving portion 3 may be formed by lamination on the first substrate 4. Alternatively, the light receiving portion 3 may be formed to be embedded inside the first substrate 4. The light receiving portion 3 may be a photoelectric conversion element 3a, and the specific structure of the light receiving portion 3 is not particularly limited. The light receiving portion 3 may include a plurality of photoelectric conversion elements 3a. The light receiving portion 3 is, for example, a photoelectric conversion element 3a of a PD (photodiode), an APD (avalanche photodiode), a SPAD (single photon avalanche diode), a ToF (time of flight) device, or the like.

[0068] The material of the photoelectric conversion element 3a is, for example, a silicon-based material, a multi-material, a perovskite, an organic material, or a quantum dot-based material. The silicon-based material is single crystal silicon, polycrystalline silicon, amorphous silicon, etc. Germanium can be used instead of silicon. Multi-materials are CuInSe2, CdGeP2, CaGa2Se4, etc. Organic materials are PEDOT:PSS, PCBM, etc. Quantum dot-based materials are PbS, etc. Note that these are just examples, and materials other than those exemplified above can be used.

[0069] The readout circuit 6 that reads out the light receiving signal received by the light receiving unit 3 is arranged on the second substrate 5. The light receiving unit 3 and the readout circuit 6 are joined by a joining member 10 such as a Cu-Cu joint, a bump or a through hole. The readout circuit 6 is arranged so that when viewed from a plan view in the normal direction of the substrate surface of the first substrate 4, at least a portion of the light receiving unit 3 overlaps with the readout circuit 6. Therefore, by arranging the joining member 10 to extend directly below the light receiving unit 3, the light receiving unit 3 and the readout circuit 6 can be joined by the joining member 10. When the light emitting unit 2 is formed on the first substrate 4, it is necessary to increase the temperature to a high temperature. For example, if the readout circuit 6 is formed on the first substrate 4 in addition to the light emitting unit 2, the readout circuit 6 may be damaged by heat. On the contrary, in the present embodiment, the light emitting unit 2 is formed on the first substrate 4, the readout circuit 6 is formed on the second substrate 5, and then the first substrate 4 and the second substrate 5 are joined together. Therefore, the readout circuit 6 will not be damaged by heat, and the reliability of the distance measuring device 1 can be improved.

[0070] Figure 2 yes Figure 1 A plan view of the light receiving unit 3 in FIG. Figure 2 As shown, the light receiving unit 3 has a plurality of pixels 60 arranged in a two-dimensional direction. The number of pixels 60 that the light receiving unit 3 has is arbitrary. Each pixel 60 can be physically separated by an element isolation region, or a diffusion region can be arranged in a boundary region between two adjacent pixels 60. Each pixel 60 has a photoelectric conversion element 3a and a pixel circuit. The pixel circuit outputs a pixel signal corresponding to the charge photoelectrically converted by the photoelectric conversion element 3a. For example, if the photoelectric conversion element 3a is a SPAD, the SPAD outputs a pixel signal indicating whether a single photon has been detected. The pixel signal output from each pixel 60 is input to the readout circuit 6 on the second substrate via the bonding member 10.

[0071] In addition, a driving circuit 9 that supplies a driving voltage to the light emitting section 2 is arranged. Figure 1 The distance measuring device 1 is formed on the second substrate 5 in the embodiment of the present invention. When the light emitting portion 2 is a semiconductor laser such as a VCSEL, the driving circuit is also referred to as an LDD (laser diode driver) 9. The LDD 9 may be arranged so that at least a portion of the light emitting portion 2 overlaps with the driving circuit when viewed in a plan view in the normal direction of the substrate surface of the first substrate 4. This makes the distance measuring device 1 smaller than when the light emitting portion 2 and the LDD 9 are laid flat.

[0072] Figure 1 The light emitting section 2 in FIG. 1 is a VCSEL, and has a laminate film 11 disposed on a first substrate 4 , a plurality of light emitting elements 2 a formed using the laminate film 11 , and an electrode 13 .

[0073] For example, the laminate film 11 is a III-V compound semiconductor material such as GaAs. Figure 1 The lower surface side of the laminate film 11 in FIG. 1 is referred to as a front surface, and the upper surface side is referred to as a rear surface.

[0074] The laminated film 11 includes a GaAs layer 27, a first multilayer reflector 14, an active layer 16, and a second multilayer reflector 18. The laser light generated in the active layer 16 resonates between the first multilayer reflector 14 and the second multilayer reflector 18 to increase the light intensity, and is emitted from the back side of the first substrate 4. The first multilayer reflector 14 and the second multilayer reflector 18 are also called DBR (distributed Bragg reflector) and are formed of, for example, AlGaAs. For example, the active layer 16 is formed of InGaAs, GainNAs, or GainNSb. The light emitting portion 2 in FIG. 3 is a backlight type because light is emitted from the back side. Figure 1 The first multilayer reflecting mirror 14, the active layer 16, the second multilayer reflecting mirror 18, and the cathode electrode 13, which are representative layers of the laminated film 11 constituting the light emitting element 2a, are shown, while other layers are omitted.

[0075] The light emitting element 2a is formed by processing the laminate film 11 into a mesa shape. An electrode 13 is arranged on the upper surface (back surface) of the light emitting element 2a. The electrode 13 is an anode electrode or a cathode electrode. Figure 1 In FIG. 1 , the arrangement of the electrodes 13 is shown in a simplified manner.

[0076] The second substrate 5 has an LDD 9 for supplying a driving signal to the light emitting element 2a of the first substrate 4. A bonding member 7 is arranged on the LDD 9 and the LDD 9 of the second substrate 5 is electrically connected to a corresponding anode electrode or cathode electrode of the first substrate 4 via the bonding member 7.

[0077] FIG. 3A to FIG. 3M 1 are cross-sectional views and plan views showing a manufacturing process of the distance measuring device 1 according to the first embodiment. Figure 3A , Figure 3C , Figure 3E , Figure 3G , Fig. 3I , Figure 3K , Figure 3L and Figure 3M is a cross-section process view, and Figure 3B , Figure 3D , Figure 3F , Figure 3H and Figure 3J It is a floor plan.

[0078] First, if Figure 3AAs shown, a first semiconductor layer 22 is formed on a first support substrate 21 for supporting a first substrate 4, and a second semiconductor layer 23 is formed inside or on the first semiconductor layer 22. For example, the first semiconductor layer 22 and the second semiconductor layer 23 are laminated on the first support substrate 21. The second semiconductor layer 23 may be a diffusion region formed by injecting impurities into a portion of the first semiconductor layer 22. Alternatively, the second semiconductor layer 23 may be laminated in a groove formed in a portion of the first semiconductor layer 2. The first semiconductor layer 22 and the second semiconductor layer 23 are formed of a semiconductor material such as silicon or germanium. The specific materials of the first semiconductor layer 22 and the second semiconductor layer 23 are not particularly limited.

[0079] Part of the first semiconductor layer 22 is arranged in the formation region of the light emitting portion 2, and the second semiconductor layer 23 is arranged in the formation region of the light receiving portion 3. Figure 3A In the process of forming the photoelectric conversion element 3a of the light receiving section 3 using the second semiconductor layer 23. When the light receiving section 3 has a plurality of pixels 60, the element isolation region is arranged in the boundary region of the pixels 60. The element isolation region may be formed by, for example, an insulating layer, or may be formed by a diffusion region formed by injecting impurities. Figure 3B As shown, the light receiving section 3 having a plurality of pixels 60 arranged in a two-dimensional direction is formed.

[0080] Then, if Figure 3C As shown, a hard mask layer 25 containing, for example, carbon is arranged on the upper surface of the first semiconductor layer 22 and the second semiconductor layer 23, and then patterned. The hard mask layer 25 is patterned on the upper surface of the first semiconductor layer 22 where the light emitting portion 2 will be formed. The size of each of the plurality of openings 25a formed by patterning the hard mask layer 25 is adjusted to the size of the light emitting element 2a. Figure 3D As shown, the plurality of openings 25a are formed in, for example, a plurality of rows.

[0081] Then, if Figure 3E As shown, a buffer layer 26 is formed on the first semiconductor layer 22. The buffer layer 26 is formed so that each of the plurality of openings 25a formed by patterning the hard mask layer 25 contacts the first semiconductor layer 22. The material of the buffer layer 26 is, for example, a Group IV material different from that of the first semiconductor layer 22. Specifically, the buffer layer 26 may be formed of germanium (Ge). Figure 3F As shown, the buffer layer 26 is formed to fill the opening 25a. The size of the opening 25a is not particularly limited.

[0082] The reason for forming the buffer layer 26 on the first semiconductor layer 22 is to make it closer to the lattice spacing of the compound semiconductor material constituting the light emitting portion 2. In other words, since the lattice spacing of germanium is closer to the lattice spacing of the compound semiconductor material than the lattice spacing of silicon, the buffer layer formed of germanium is arranged on the first substrate 4 so that the buffer layer 26 and the compound semiconductor material layer constituting the light emitting portion 2 are in contact with each other. This can suppress deformation and crystal defects in the first substrate 4 compared to when the first semiconductor layer 22 on the first substrate 4 is in direct contact with the compound semiconductor material layer.

[0083] Next, if Figure 3G The cross-sectional view and Figure 3H As shown in the plan view of FIG. 1 , the light emitting portion 2 is formed on the buffer layer 26 by selective epitaxial growth. The light emitting portion 2 is, for example, Figure 1 The VCSEL shown in FIG. 1 has a laminate film 11, an anode electrode, and a cathode electrode. The laminate film 11 is, for example, a laminate of a first multilayer reflector 14, an active layer 16, and a second multilayer reflector 18. As described later, a GaAs layer may be arranged between the first multilayer reflector 14 and the buffer layer 26.

[0084] The first multilayer reflector 14 is laminated on the buffer layer 26. The first multilayer reflector 14 and the second multilayer reflector 18 are formed of a material such as AlGaAs. The active layer 16 is formed of a material such as InGaAs or GaInNA(Sb). An AlAs layer may be arranged between the active layer 16 and the multilayer reflector thereon. The sidewalls of the laminated film 11 are protected by an insulating layer 29 such as SiO2 or SiN.

[0085] As described above, each layer constituting the laminate film 11 is formed of a compound semiconductor material and is sequentially laminated on a buffer layer formed of germanium by selective epitaxial growth. By adopting the selective epitaxial growth method, uniform thin films can be formed in a plurality of layers.

[0086] Next, as shown in FIG31 , an electrode (eg, cathode electrode 13) is formed on the upper surface of the light emitting portion 2. Figure 3J As shown, the light emitting unit 2 has a plurality of light emitting element groups 2b arranged along the first direction X and extending in the second direction Y. Each light emitting element group 2b has a plurality of light emitting elements 2a. A cathode electrode 13 is provided in each light emitting element group 2b. The number and shape of the light emitting element groups 2b are arbitrary.

[0087] Next, if Figure 3K As shown, with downward facing Figure 3J The first substrate 4 having the cathode electrode 13 is bonded to the second support substrate 28 arranged therebelow. An insulating layer 30 of SiO 2 , SiN or the like is formed between the second support substrate 28 and the light emitting section 2 .

[0088] Next, if Figure 3L As shown, the first support substrate 21 is peeled off, and the wiring layer 31 is formed on the first substrate 4 in a post-process. For example, after the first support substrate 21 is peeled off, an insulating layer 32 formed of SiO2 is formed, a groove 33 is formed in the insulating layer 32, and a metal material is filled in the groove 33 to form the wiring layer 31.

[0089] Next, if Figure 3M As shown, the second support substrate 28 is peeled off, and the first semiconductor layer 22 is thinned by CMP (Chemical Mechanical Polishing) or the like, and then the second substrate 5 on which the logic circuit is formed is bonded.

[0090] The logic circuit formed on the second substrate 5 has an LDD 9 connected to the light emitting section 2 and a readout circuit 6 connected to the light receiving section 3. The second substrate 5 on which the logic circuit is formed is made of Figures 3A to 3G The manufacturing process is separated from the manufacturing process, and Figure 3H is bonded to the first substrate 4 during the process.

[0091] The light emitting section 2 of the first substrate 4 and the LDD 9 of the second substrate 5 are joined by a joining member 7 extending in the depth direction of the first substrate 4, and the light receiving section 3 of the first substrate 4 and the readout circuit 6 of the second substrate 5 are joined by a joining member 10 extending in the depth direction of the first substrate 4. Thereafter, packaging is performed by covering the edges of the joined first and second substrates 4 and 5 with a resin, for example.

[0092] Thus, in the first embodiment, the light emitting unit 2 and the light receiving unit 3 are integrally formed on the first substrate 4, so the manufacturing process can be simplified and the device can be made smaller compared to the case where the light emitting unit 2 and the light receiving unit 3 are manufactured separately and mounted on the same substrate. By simplifying the manufacturing process, the manufacturing cost of the distance measuring device 1 can be reduced.

[0093] (Second Embodiment)

[0094] The distance measuring device 1 according to the second embodiment has a light shielding member arranged between the light emitting section 2 and the light receiving section 3 .

[0095] Figure 4 is a cross-sectional view of a distance measuring device 1 according to a second embodiment. Figure 4 In, with Figure 1 The same components are denoted by the same reference numerals, and the differences will be mainly described below.

[0096] exist Figure 4 In the distance measuring device 1 of FIG. 1 , the light shielding member 40 is arranged between the light emitting section 2 and the light receiving section 3. For example, the light shielding member 40 is arranged to penetrate the first substrate 4 in the depth direction.

[0097] The light shielding member 40 is formed of a metal material such as tungsten that has light shielding properties for visible light and infrared light. For example, the light shielding member 40 is arranged in a boundary area in the direction in which the light emitting portion 2 and the light receiving portion 3 are arranged. Alternatively, the light shielding member 40 may be arranged to surround at least one of the light receiving portion 3 or the light emitting portion 2.

[0098] The light shielding member 40 may have a height approximately equal to or greater than that of the light emitting portion 2. This can improve light shielding efficiency even if the light emitting portion 2 is formed at a position higher than the light receiving portion 3.

[0099] Thus, by providing the light shielding member 40 , light emitted from the light emitting section 2 can be prevented from directly entering the light receiving section 3 , and the light receiving section 3 is not affected by crosstalk, thereby improving the light receiving characteristics of the light receiving section 3 .

[0100] (Third Embodiment)

[0101] In the third embodiment, the light emitting section 2 is arranged just above the LDD 9 and adjacent to the LDD 9 .

[0102] Figure 5 is a cross-sectional view of a distance measuring device 1 according to a third embodiment. Figure 5 In, with Figure 1 The same components are denoted by the same reference numerals, and the differences will be mainly described below.

[0103] exist Figure 5 In the distance measuring device 1, the light emitting unit 2 is arranged in the first substrate 4, and Figure 5 The light emitting part 2 is arranged as Figure 1 The light emitting portion 2 is closer to the second substrate 5. More specifically, Figure 5 The light emitting portion 2 is arranged just above the LDD 9 and adjacent to the LDD 9 .

[0104] The bottom surface of the light emitting portion 2 and the bottom surface of the light receiving portion 3 can be at the same height. This makes the height of the bonding member 7 that bonds the light emitting portion 2 to the LDD 9 the same as the height of the bonding member 10 that bonds the light receiving portion 3 to the readout circuit 6, making the process of forming the bonding members 7 and 10 easier.

[0105] In this way, by arranging the light emitting portion 2 close to the second substrate 5, the height of the first substrate 4 can be reduced, and the height of the distance measuring device 1 in the state where the second substrate 5 is bonded to the first substrate 4 can be reduced, forming a lighter, thinner, shorter and smaller device. In addition, the bonding member 7 bonding the light emitting element 2a to the LDD 9 and the bonding member 10 bonding the light receiving portion 3 to the readout circuit 6 can be shortened, so that the resistance value of the bonding members 7 and 10 can be reduced, and power loss can be suppressed.

[0106] (Fourth Embodiment)

[0107] In the fifth embodiment, the bonding member 7 is not arranged right below the light emitting portion 2 .

[0108] Figure 6 is a cross-sectional view of a distance measuring device 1 according to a fourth embodiment. Figure 6 In, with Figure 1 The same components are denoted by the same reference numerals, and the differences will be mainly described below.

[0109] exist Figure 6 In the distance measuring device 1, the light emitting unit 2 is arranged on the first substrate 4, as in Figure 1 The diffusion region 41 is arranged near the upper surface of the first substrate 4 just below the light emitting portion 2. The diffusion region 41 is connected to the cathode electrode or the anode electrode of the light emitting portion 2. The diffusion region 41 is a region where impurity ions are injected and diffused, and the conductivity of the diffusion region 41 can be increased by adjusting the amount of the injected impurity ions so that it can be used as a conductive region.

[0110] The bonding member 7a is arranged to extend from the end of the diffusion region 41 in the depth direction of the first substrate 4. The bonding member 7a extends to the second substrate 5. The second substrate 5 has a bonding member 7b extending from the LDD 9 in a direction substantially parallel to the substrate surface, and the bonding member 7b is bonded to the above-mentioned bonding member 7a.

[0111] Figure 6 The distance measuring device 1 in the embodiment has the above-mentioned bonding members 7a and 7b, so it is not necessary to arrange the bonding member 7 directly below the light emitting portion 2. Therefore, the area directly below the light emitting portion 2 can be used for purposes other than arranging the bonding member 7, allowing greater design freedom. In addition, there are fewer restrictions on the position of the bonding member 7 that bonds the light emitting portion 2 to the LDD 9.

[0112] In this way, the bonding members 7a and 7b that bond the light emitting portion 2 to the LDD 9 according to the fourth embodiment are arranged near the ends of the light emitting portion 2, rather than directly below the light emitting portion 2. Therefore, the area directly below the light emitting portion 2 can be used for purposes other than arranging the bonding members 7, and there are fewer restrictions on the position of the bonding members 7, allowing greater design freedom.

[0113] (Fifth Embodiment)

[0114] In the first to fourth embodiments, the light emitting section 2 and the LDD 9 are arranged to overlap when viewed in a plan view in the normal direction of the substrate surface of the first substrate 4. In contrast, in the fifth embodiment, the light emitting section 2 and the LDD 9 are arranged not to overlap.

[0115] Figure 7 is a cross-sectional view of a distance measuring device 1 according to a fifth embodiment. Figure 7 In, with Figure 1 The same components are denoted by the same reference numerals, and the differences will be mainly described below.

[0116] exist Figure 7 In the distance measuring device 1, the light emitting portion 2 and the LDD 9 are arranged so as not to overlap when viewed in a plan view in the normal direction of the substrate surface of the first substrate 4. For example, the LDD 9 of the second substrate 5 is arranged at a position offset from directly below the light emitting portion 2 of the first substrate 4, for example, near the end of the second substrate 5. The bonding member 7a is provided to extend from the vicinity of the end of the light emitting portion 2 in the depth direction of the first substrate 4. The bonding member 7a extends to the second substrate 5. The second substrate 5 has a bonding member 7b extending from the LDD 9 in a direction substantially parallel to the substrate surface, and the bonding member 7b is bonded to the above-mentioned bonding member 7a.

[0117] Therefore, the position of the LDD 9 is not necessarily limited to being directly below the light emitting portion 2, and it may be located at any position on the second substrate 5. For example, if the readout circuit 6 provided on the second substrate 5 requires an area larger than the area of ​​the light receiving portion 3 provided on the first substrate 4, the readout circuit 6 may be arranged directly below the light emitting portion 2 of the first substrate 4. In this case, the LDD 9 cannot be arranged on the second substrate 5 so as to overlap with the light emitting portion 2.

[0118] In this embodiment, LDD 9 can be set on the second substrate 5 without considering the position of the light emitting portion 2 of the first substrate 4, thereby improving the degree of freedom in design. In this embodiment, the position of the bonding member 7 for bonding with the light emitting portion 2 can be determined according to the position of LDD 9.

[0119] (Sixth Embodiment)

[0120] In the first to fifth embodiments, the readout circuit 6 is provided on the second substrate 5, but in some cases, it may be desirable to arrange a part of the readout circuit 6 near the light receiving section 3 in terms of electrical characteristics. For example, for the purpose of noise reduction, etc., it is desirable to arrange a source follower circuit as a part of the readout circuit 6 near the light receiving section 3. The source follower circuit is a circuit that transmits a voltage signal generated by photoelectric conversion in the light receiving section 3 to a signal wiring connected to the readout circuit 6 with low impedance. Therefore, in the distance measuring device 1 according to the sixth embodiment, a part of the readout circuit (for example, the source follower circuit) is arranged on the first substrate 4.

[0121] Figure 8 4 is a plan view of the light receiving section 3 on the first substrate 4. Figure 8As shown, the light emitting section 2, the light receiving section 3 and a portion 6a of the readout circuit 6 are arranged on the first substrate 4. The portion 6a of the readout circuit includes, for example, a source follower circuit. Since a source follower circuit is provided for each pixel 60, a portion 6a of the readout circuit including the source follower circuit is arranged on the first substrate 4, which is associated with each of the photoelectric conversion elements 3a constituting the light receiving section 3.

[0122] A portion 6 a of the readout circuit provided on the first substrate 4 and the readout circuit on the second substrate 5 are joined by a joining member 7 such as a Cu—Cu joint, a bump, or a through-hole.

[0123] Figure 8 The light emitting unit 2 of the distance measuring device 1 is connected to Figure 1 Configure in the same way. Figure 8 The light emitting part 2 of the distance measuring device 1 can be connected with Figure 5 The height of the first substrate 4 can be reduced by configuring in the same manner as in FIG.

[0124] Thus, in the sixth embodiment, a portion 6 a of the readout circuit provided on the second substrate 5 is provided on the first substrate 4 , so that a source follower circuit or the like can be arranged near the light receiving section 3 , and the light receiving characteristics of the light receiving section 3 can be improved.

[0125] (Seventh Embodiment)

[0126] Fig. 9 1 is a plan view of a distance measuring device 1 according to a seventh embodiment. The light emitting section 2 has a plurality of light emitting elements 2a. The light emitting elements 2a are arranged adjacent to each other in a first direction X and a second direction Y. The light receiving section 3 has a plurality of photoelectric conversion elements 3a. The photoelectric conversion elements 3a are arranged adjacent to each other in a first direction X and a second direction Y.

[0127] exist Fig. 9 In the embodiment, the light emitting section 2 and the light receiving section 3 are arranged adjacent to each other in the first direction X of the first substrate 4. The light emitting elements 2a constituting the light emitting section 2 are arranged adjacent to each other so that the light emitting section 2 can emit surface light. The photoelectric conversion elements 3a constituting the light receiving section 3 are arranged adjacent to each other so that the surface light can be received by the photoelectric conversion elements 3a. This allows distance measurement of objects located over a wide range.

[0128] Fig.10 1 is a plan view of a distance measuring device 1 according to a first modified example of the seventh embodiment. Fig. 9 In the embodiment, the arrangement region of the plurality of photoelectric conversion elements 3a in the light receiving section 3 is arranged adjacent to the arrangement region of the plurality of light emitting elements 2a in the light emitting section 2. Fig.10In the embodiment, a plurality of light emitting elements 2a and a plurality of photoelectric conversion elements 3a are arranged in a mixed manner in the same arrangement region.

[0129] exist Fig.10 In the case of Fig. 9 and can make the distance measuring device 1 narrower than Fig. 9 Small in the middle.

[0130] Fig.11 is a plan view of a distance measuring device 1 according to a second modified example of the seventh embodiment. Fig.11 In the embodiment, the plurality of photoelectric conversion elements 3a in the light receiving section 3 are arranged close to each other in the first direction X and the second direction Y, and the plurality of light emitting elements 2a in the light emitting section 2 are arranged to surround the light receiving section 3. Fig.11 In contrast, the light emitting elements 2 a in the light emitting section 2 may be arranged close to each other in the first direction X and the second direction Y, and the photoelectric conversion elements 3 a in the light receiving section 3 may be arranged to surround the light emitting section 2 .

[0131] Thus, in the seventh embodiment, when the light emitting section 2 has a plurality of light emitting elements 2a and the light receiving section 3 has a plurality of photoelectric conversion elements 3a, the light emitting elements 2a and the photoelectric conversion elements 3a can be arranged in any arrangement, so that the degree of freedom in design can be increased.

[0132] (Specific Configuration of Distance Measuring Device 1)

[0133] The distance measuring device 1 of the first to seventh embodiments can be applied to the dToF (direct ToF) method and the iToF (indirect ToF) method. The dToF method is a method for measuring the distance based on the time difference between the light emission timing of the light emitting unit 2 and the light reception timing of the light receiving unit 3. The iToF method is a method for measuring the distance based on the phase difference between the phase of the light emission signal of the light emitting unit 2 and the phase of the light reception signal of the light receiving unit 3.

[0134] Fig.12 is a block diagram of the distance measuring device 1 according to the first to seventh embodiments. Fig.12 The block structure of the distance measurement device 1 using the dToF method is shown. Figure 1 The distance measuring device 1 includes a light emitting section 2 , a distance measuring unit 51 and an overall control unit 52 .

[0135] The light emitting section 2 includes a plurality of light emitting elements 2 a , a drive circuit 53 , a clock generating unit 54 , and a light emission control unit 55 .

[0136] The plurality of light emitting elements 2a are arranged in the intersecting first direction X and second direction Y. The plurality of light emitting elements 2a repeatedly emit light emitting pulse signals at predetermined time intervals. The light emitting unit 2 can scan a predetermined two-dimensional space using the light signals emitted by the plurality of light emitting elements 2a. There is no particular limitation on the specific method of scanning the light signal. The light emitting element 2a is, for example, a VCSEL.

[0137] The driving circuit 53 drives the light emitting element 2a based on the control signal from the light emitting control unit 55. For example, the driving circuit 53 controls at least one of the light emitting timing and the light emitting waveform of the light pulse signal according to the control signal from the light emitting control unit 55. More specifically, the driving circuit 53 controls the voltage level of the voltage applied to the anode or cathode of the light emitting element 2a based on the control signal from the light emitting control unit 55 to control at least one of the signal intensity, optical peak intensity, pulse width, rising edge timing, falling edge timing, and conversion rate of the light pulse signal from the light emitting element 2a.

[0138] The clock generating unit 54 generates a clock signal synchronized with a reference clock signal. The reference clock signal is, for example, a signal input from the outside of the distance measuring device 1. Alternatively, the reference clock signal may be generated inside the distance measuring device 1.

[0139] The light emission control unit 55 generates a control signal for controlling at least one of the light emission timing and the light emission waveform of the light emitting element 2 a in synchronization with the clock signal. At least one of the drive circuit 53 , the clock generation unit 54 , and the light emission control unit 55 is provided in the LDD 9 .

[0140] The overall control unit 52 controls the light emitting section 2 and the distance measuring unit 51. At least one of the light emitting section 2 and the overall control unit 52 may be integrated into the distance measuring unit 51.

[0141] The distance measurement unit 51 has a pixel array unit 61, a distance measurement processing unit 62, a control unit 63, a clock generation unit 64, a light emission timing control unit 65, a drive circuit 66, and an output buffer 67. The pixel array unit 61 constitutes the light receiving section 3.

[0142] The pixel array unit 61 has a plurality of pixels 60 arranged in a first direction X and a second direction Y. The pixels 60 receive reflected light signals from the object 50. The pixels 60 output voltage signals in response to the arrival of photons. The light intensity of the reflected light signals can also be detected by averaging the results of repeatedly receiving the reflected light signals at each pixel 60.

[0143] Each pixel 60 has a photoelectric conversion element 3a. The photoelectric conversion element 3a is, for example, a SPAD (single photon avalanche photodiode). Each pixel 60 may have a quenching circuit (not shown). In the initial state, the quenching circuit supplies a reverse bias voltage between the anode and cathode of the SPAD, where the potential difference exceeds the breakdown voltage. After the SPAD detects a photon, the drive circuit 66 supplies a reverse bias voltage to the SPAD via a corresponding quenching circuit to prepare for detecting the reflected light pulse signal.

[0144] The distance measurement processing unit 62 has a time-to-digital converter (TDC) 71 , a histogram generating unit 72 , a signal processing unit 73 , and a distance measurement control unit 74 .

[0145] The TDC 71 generates a time digital signal corresponding to the reception time of the reflected light pulse signal with a predetermined time resolution received by the SPAD. The histogram generation unit 72 generates a histogram with a bin width corresponding to the time resolution of the TDC 71 based on the time digital signal generated by the TDC 71. The bin width is the width of each frequency unit constituting the histogram. The higher the time resolution of the TDC 71, the narrower the bin width can be, and a histogram that more accurately reflects the time frequency of the received reflected light pulse signal can be obtained.

[0146] The signal processing unit 73 calculates the distance to the object 50 by calculating the center of gravity of the reflected light pulse signal based on the histogram, and outputs the distance via the output buffer 67 .

[0147] The control unit 63 controls the processing actions of each unit in the distance measurement unit 51. The distance measurement control unit 74 controls the TDC 71, the histogram generation unit 72, and the signal processing unit 73 in the distance measurement processing unit 62. The light emission timing control unit 65 controls the light emission control unit 55 in the light emitting section 2, and also controls the drive circuit 66. When the plurality of pixels 60 in the pixel array unit 61 detect light and the cathode voltage drops, the drive circuit 66 performs quenching control to restore the cathode voltage to its original voltage.

[0148] Clock Generating Unit The clock generating unit 64 generates a clock signal used by the TDC 71 and the histogram generating unit 72. The clock generating unit 64 generates the clock signal using, for example, a PLL circuit (not shown).

[0149] At least one of the driving circuit 66, the ranging processing unit 62, the control unit 63, the clock generating unit 64, and the light emission timing control unit 65 is provided in the readout circuit 6 of the second substrate 5. Among the driving circuit 66, the ranging processing unit 62, the control unit 63, the clock generating unit 64, and the light emission timing control unit 65, a portion not included in the readout circuit 6 may be arranged on the first substrate 4.

[0150] The overall control unit 52 is provided in the LDD 9 or the readout circuit 6. Alternatively, the overall control unit 52 may be arranged on the first substrate 4.

[0151] so, Fig.12 The distance measuring device 1 may be arranged on the first substrate 4 and the second substrate 5 and may be configured with a single semiconductor chip.

[0152] (Application Examples)

[0153] The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure can be implemented as a device installed on any kind of mobile body (such as a car, an electric vehicle, a hybrid vehicle, a motorcycle, a bicycle, a personal mobile, an airplane, a drone, a ship, a robot, an engineering machine, or an agricultural machine (tractor)).

[0154] Fig.13 7000 is a block diagram showing an example of a schematic configuration of a vehicle control system 7000, which is an example of a mobile body control system to which the technology according to the embodiment of the present disclosure can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected to each other via a communication network 7010. Fig.13 In the example shown, the vehicle control system 7000 includes a drive system control unit 7100, a body system control unit 7200, a battery control unit 7300, an external information detection unit 7400, an internal information detection unit 7500, and an integrated control unit 7600. The communication network 7010 that connects the plurality of control units to each other may be an in-vehicle communication network conforming to any standard, such as a controller area network (CAN), a local interconnect network (LIN), a local area network (LAN), FlexRay (registered trademark), and the like.

[0155] Each control unit includes: a microcomputer that performs calculation processing according to various programs; a storage unit that stores programs executed by the microcomputer, parameters for various operations, etc.; and a drive circuit that drives various control target devices. Each control unit further includes: a network interface (I / F) for performing communication with other control units via the communication network 7010; and a communication I / F for performing communication with devices, sensors, etc. inside and outside the vehicle through wired communication or radio communication. Fig.13The functional configuration of the integrated control unit 7600 shown includes a microcomputer 7610, a general communication I / F 7620, a dedicated communication I / F 7630, a positioning unit 7640, a beacon receiving unit 7650, an in-vehicle device I / F 7660, a sound / image output unit 7670, an in-vehicle network I / F 7680, and a storage unit 7690. Other control units also similarly include a microcomputer, a communication I / F, a storage unit, and the like.

[0156] The drive system control unit 7100 controls the operation of the devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 7100 is used as a control device to control: a drive force generating device for generating the drive force of the vehicle, such as an internal combustion engine, a drive motor, etc.; a drive force transmission mechanism for transmitting the drive force to the wheels; a steering mechanism for adjusting the steering angle of the vehicle; a brake device for generating the braking force of the vehicle, etc. The drive system control unit 7100 may have the function of a control device for an anti-lock braking system (ABS), an electronic stability control (ESC), etc.

[0157] The drive system control unit 7100 is connected to a vehicle state detection unit 7110. The vehicle state detection unit 7110 includes, for example, at least one of the following items: a gyro sensor for detecting the angular velocity of the axial rotational motion of the vehicle body, an acceleration sensor for detecting the acceleration of the vehicle, and a sensor for detecting the operation amount of the accelerator pedal, the operation amount of the brake pedal, the steering angle of the steering wheel, the engine speed or the rotation speed of the wheel, etc. The drive system control unit 7100 performs calculation processing using the signal input from the vehicle state detection unit 7110 to control the internal combustion engine, the drive motor, the electric power steering device, the brake device, etc.

[0158] The body system control unit 7200 controls the operation of various devices installed on the body according to various programs. For example, the body system control unit 7200 is used as a control device to control: a keyless entry system, a smart key system, a power window device, or various lights such as headlights, reverse lights, brake lights, turn signals, fog lights, etc. In this case, the body system control unit 12020 can receive radio waves transmitted from a mobile device that replaces the key or signals from various switches as input. The body system control unit 7200 receives these input radio waves or signals to control the vehicle's door lock devices, power window devices, lights, etc.

[0159] The battery control unit 7300 controls the secondary battery 7310 used as a power source for driving the motor according to various programs. For example, the battery control unit 7300 receives information about battery temperature, battery output voltage, remaining battery power, etc. from a battery device including the secondary battery 7310. The battery control unit 7300 uses these signals to perform calculation processing, perform temperature adjustment control of the secondary battery 7310, or control a cooling device of the battery device, etc.

[0160] The vehicle exterior information detection unit 7400 detects information outside the vehicle including the vehicle control system 7000. For example, the vehicle exterior information detection unit 7400 is connected to at least one of the imaging unit 7410 and the vehicle exterior information detection unit 7420. The imaging unit 7410 includes at least one of a time-of-flight (ToF) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The vehicle exterior information detection unit 7420 may include at least one of the following items: an environmental sensor for detecting current atmospheric conditions or weather conditions, and a peripheral information detection sensor for detecting other vehicles, obstacles, pedestrians, etc. around the vehicle including the vehicle control system 7000.

[0161] The environmental sensor may be, for example, at least one of the following: a raindrop sensor for detecting rain, a fog sensor for detecting fog, a sunshine sensor for detecting the degree of sunshine, and a snow sensor for detecting snowfall. The peripheral information detection sensor may be at least one of the following: an ultrasonic sensor, a radar device, and a LIDAR device (a light detection and distance measurement device, or a laser imaging detection and distance measurement device). Each of the imaging unit 7410 and the vehicle exterior information detection unit 7420 may be set as an independent sensor or device, or may be set as a device in which a plurality of sensors or devices are integrated.

[0162] Fig.14 An example of the installation position of the imaging unit 7410 and the vehicle exterior information detection unit 7420 is shown. The imaging units 7910, 7912, 7914, 7916 and 7918 may be arranged at the positions of the front nose, side mirrors, rear bumper, rear door and the upper part of the windshield inside the vehicle 7900. The imaging unit 7910 arranged at the front nose and the imaging unit 7918 arranged at the upper part of the windshield inside the vehicle mainly obtain the image in front of the vehicle 7900. The imaging units 7912 and 7914 arranged at the side mirrors mainly obtain the image of the side of the vehicle 7900. The imaging unit 7916 arranged at the rear bumper or rear door mainly obtains the image of the rear of the vehicle 7900. The imaging unit 7918 arranged at the upper part of the windshield inside the vehicle is mainly used to detect the front vehicle, pedestrians, obstacles, signals, traffic signs, lanes, etc.

[0163] By the way, Fig.14An example of the shooting range of each imaging unit 7910, 7912, 7914 and 7916 is shown. Imaging range a represents the imaging range of the imaging unit 7910 arranged at the front nose. Imaging ranges b and c respectively represent the imaging ranges of the imaging units 7912 and 7914 arranged at the side mirrors. Imaging range d represents the imaging range of the imaging unit 7916 arranged at the rear bumper or the rear door. For example, a bird's-eye view image of the vehicle 7900 observed from above can be obtained by superimposing image data imaged by the imaging units 7910, 7912, 7914 and 7916.

[0164] The vehicle exterior information detection units 7920, 7922, 7924, 7926, 7928, and 7930 arranged at the front, rear, side, and corner of the vehicle 7900 and the upper portion of the windshield inside the vehicle may be ultrasonic sensors or radar devices. The vehicle exterior information detection units 7920, 7926, and 7930 arranged at the front nose of the vehicle 7900, the rear bumper of the vehicle 7900, the rear door, and the upper portion of the windshield inside the vehicle may be LIDAR devices. These vehicle exterior information detection units 7920-7930 are mainly used to detect vehicles ahead, pedestrians, obstacles, and the like.

[0165] Back to Fig.13 , continue to describe. The vehicle exterior information detection unit 7400 causes the imaging unit 7410 to image the image outside the vehicle and receive the imaged image data. In addition, the vehicle exterior information detection unit 7400 receives detection information from the vehicle exterior information detection unit 7420 connected to the vehicle exterior information detection unit 7400. When the vehicle exterior information detection unit 7420 is an ultrasonic sensor, a radar device, or a LIDAR device, the vehicle exterior information detection unit 7400 causes ultrasonic waves, electromagnetic waves, etc. to be transmitted, and receives information about the received reflected waves. Based on the received information, the vehicle exterior information detection unit 7400 may perform processing of detecting objects (such as people, vehicles, obstacles, signs, symbols, etc. on the road surface), or perform processing of detecting the distance of the object. The vehicle exterior information detection unit 7400 may perform environmental recognition processing based on the received information to identify rainfall, fog, road conditions, etc. The vehicle exterior information detection unit 7400 may calculate the distance to the object outside the vehicle based on the received information.

[0166] In addition, based on the received image data, the vehicle exterior information detection unit 7400 may perform image recognition processing for identifying an object (such as a person, vehicle, obstacle, sign, symbol, etc. on the road), or perform processing for detecting the distance of the object. The vehicle exterior information detection unit 7400 may perform processing such as distortion correction, alignment, etc. on the received image data, and generate a bird's-eye view image or a panoramic image by combining image data imaged by a plurality of different imaging units 7410. The vehicle exterior information detection unit 7400 may perform viewpoint conversion processing using image data imaged by different imaging units 7410.

[0167] The in-vehicle information detection unit 7500 detects information inside the vehicle. The in-vehicle information detection unit 7500 may be connected to a driver state detection unit 7510 that detects the driver's state. The driver state detection unit 7510 may include a camera for photographing the driver, a biosensor for detecting the driver's biometric information, a microphone for collecting sounds inside the vehicle, and the like. The biosensor may be arranged on a seat surface, a steering wheel, and the like, and detects biometric information of a passenger sitting in a seat or a driver holding the steering wheel. Based on the detection information input from the driver state detection unit 7510, the in-vehicle information detection unit 7500 may calculate the driver's fatigue level or the driver's concentration level, or may distinguish whether the driver is dozing off. The in-vehicle information detection unit 7500 may perform processing such as noise elimination processing on the audio signal obtained by sound collection.

[0168] The integrated control unit 7600 controls the overall operation within the vehicle control system 7000 according to various programs. The integrated control unit 7600 is connected to the input unit 7800. The input unit 7800 is a device that can be operated by the passenger, such as a touch panel, a button, a microphone, a switch, a joystick, etc. The integrated control unit 7600 can receive data obtained by voice recognition of the voice input via the microphone. The input unit 7800 can be a remote control device using infrared or other radio waves, or can be an external connection device such as a mobile phone, a personal digital assistant (PDA), etc. that supports the operation of the vehicle control system 7000. The input unit 7800 can be a camera. In this case, the passenger can input information through gestures. Alternatively, data obtained by detecting the movement of a wearable device worn by the passenger can be input. In addition, the input unit 7800 may include an input control circuit, etc., which generates an input signal based on the information input by the passenger, etc. using the above-mentioned input unit 7800, and outputs the generated input signal to the integrated control unit 7600. Passengers and the like can input various data into the vehicle control system 7000 through the operation input unit 7800 to process operation instructions.

[0169] The storage unit 7690 may include a read-only memory (ROM) storing various programs executed by the microcomputer and a random access memory (RAM) storing various parameters, operation results, sensor values, etc. In addition, the storage unit 7690 may be a magnetic storage device such as a hard disk drive (HDD), a semiconductor storage device, an optical storage device, a magneto-optical storage device, etc.

[0170] The general communication I / F 7620 is a widely used communication I / F that mediates communication with various devices existing in the external environment 7750. The general communication I / F 7620 can implement: cellular communication protocols such as Global System for Mobile Communications (GSM (registered trademark)), Worldwide Interoperability for Microwave Access (WiMAX (registered trademark)), Long Term Evolution (LTE (registered trademark)), LTE Advanced (LTE-A), etc., or other wireless communication protocols such as wireless LAN (also known as Wireless Fidelity (Wi-Fi (registered trademark)), Bluetooth (registered trademark), etc. The general communication I / F 7620 can be connected to a device (e.g., an application server or a control server) existing on an external network (e.g., the Internet, a cloud network, or a company-specific network) via a base station or an access point. In addition, the general communication I / F 7620 can be connected to a terminal (e.g., a terminal of a driver, a pedestrian, or a store, or a machine type communication (MTC) terminal) existing near the vehicle using a peer-to-peer (P2P) technology.

[0171] The dedicated communication I / F 7630 is a communication I / F that supports a communication protocol developed for vehicle use. The dedicated communication I / F 7630 can implement: a standard protocol, for example, Wireless Access in Vehicular Environments (WAVE) (which is a combination of the Institute of Electrical and Electronics Engineers (IEEE) 802.11p as a lower layer and IEEE 1609 as an upper layer), a dedicated short-range communication (DSRC), or a cellular communication protocol. The dedicated communication I / F 7630 generally performs V2X communication including one or more of the following concepts: communication between vehicles and vehicles (vehicle-to-vehicle), communication between roads and vehicles (vehicle-to-infrastructure), communication between vehicles and homes (vehicle-to-home), and communication between pedestrians and vehicles (vehicle-to-pedestrian).

[0172] The positioning unit 7640 can perform positioning by receiving a global navigation satellite system (GNSS) signal from a GNSS satellite (e.g., a GPS signal from a global positioning system (GPS) satellite) to generate position information including the latitude, longitude, and altitude of the vehicle. Incidentally, the positioning unit 7640 can identify the current position by exchanging signals with a wireless access point, and can also obtain position information from a terminal such as a mobile phone, a personal handyphone system (PHS), or a smart phone with a positioning function.

[0173] The beacon receiving unit 7650 can receive radio waves or electromagnetic waves transmitted from a radio station installed on a road or the like, thereby obtaining information on the current position, congestion, road closure, required time, etc. Incidentally, the function of the beacon receiving unit 7650 may be included in the above-mentioned dedicated communication I / F 7630.

[0174] The in-vehicle device I / F 7660 is a communication interface that mediates the connection between the microcomputer 7610 and various in-vehicle devices 7760 present in the vehicle. The in-vehicle device I / F 7660 can establish a wireless connection using wireless communication protocols such as wireless LAN, Bluetooth (registered trademark), near field communication (NFC), or wireless universal serial bus (WUSB). In addition, the in-vehicle device I / F 7660 can establish a wired connection through a universal serial bus (USB), a high-definition multimedia interface (HDMI (registered trademark)), a mobile high-definition link (MHL), etc. via a connection terminal (and a cable, if necessary) not shown in the figure. The in-vehicle device 7760 may include at least one of the following items: a mobile device and a wearable device owned by a passenger and an information device loaded into or attached to the vehicle. The in-vehicle device 7760 may also include a navigation device that searches for a path to an arbitrary destination. The in-vehicle device I / F 7660 exchanges control signals or data signals with these in-vehicle devices 7760.

[0175] The in-vehicle network I / F 7680 is an interface that mediates communication between the microcomputer 7610 and the communication network 7010. The in-vehicle network I / F 7680 transmits and receives signals and the like in accordance with a predetermined protocol supported by the communication network 7010.

[0176] The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 according to various programs based on information obtained via at least one of the general communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the vehicle network I / F 7680. For example, the microcomputer 7610 may calculate a control target value for a driving force generating device, a steering mechanism, or a braking device based on the obtained vehicle interior or vehicle exterior related information, and output a control command to the drive system control unit 7100. For example, the microcomputer 7610 may perform cooperative control aimed at realizing functions of an advanced driver assistance system (ADAS), including collision avoidance or impact buffering for a vehicle, following driving based on a vehicle-to-vehicle distance, vehicle speed keeping driving, a vehicle collision warning, a vehicle lane departure warning, and the like. In addition, the microcomputer 7610 can control the drive force generation device, the steering mechanism, the braking device based on the information obtained about the vehicle's surroundings, thereby performing cooperative control intended for automatic driving, etc. that does not depend on the driver's operation.

[0177] The microcomputer 7610 may generate three-dimensional distance information between the vehicle and objects such as surrounding structures and people based on information obtained via at least one of the general communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the vehicle network I / F 7680, and generate local map information including information about the surrounding environment in which the vehicle is currently located. In addition, the microcomputer 7610 may predict dangers such as collision of the vehicle, approach of pedestrians, etc., entering a closed road, etc. based on the obtained information, and generate an alarm signal. The alarm signal may be a signal for generating a warning sound or lighting an alarm lamp.

[0178] The sound / image output unit 7670 transmits an output signal of at least one of sound and image to an output device, which can visually or auditorily notify information to the passengers of the vehicle or the outside of the vehicle. Fig.13 In the example, the audio speaker 7710, the display unit 7720 and the instrument panel 7730 are shown as output devices. The display unit 7720 may include at least one of an on-board display and a head-up display. The display unit 7720 may have an augmented reality (AR) display function. The output device may be other devices other than these devices, such as headphones, wearable devices such as eyeglass displays worn by passengers, projectors, lights, etc. In the case where the output device is a display device, the display device visually displays the results obtained by various processes performed by the microcomputer 7610, or displays information received from other control units in various forms (such as text, images, tables, graphs, etc.). In addition, in the case where the output device is an audio output device, the audio output device converts an audio signal composed of played audio data or sound data into an analog signal and outputs the analog signal in an auditory manner.

[0179] By the way, in Fig.13 In the example shown, at least two control units connected to each other via the communication network 7010 may be integrated into one control unit. Alternatively, each individual control unit may include multiple control units. In addition, the vehicle control system 7000 may include other control units not shown in the figure. In addition, part or all of the functions performed by one of the control units in the above description may be assigned to another control unit. That is, a predetermined operation process may be performed by any control unit as long as the information is transmitted and received via the communication network 7010. Similarly, a sensor or device connected to one of the control units may be connected to another control unit, and multiple control units may transmit and receive detection information to each other via the communication network 7010.

[0180] In the above vehicle control system 7000, see Figure 1The distance measuring device 1 according to the present embodiment described can be applied to Fig.13 An integrated control unit 7600 of an application example is shown.

[0181] In addition, see Figure 1 At least some of the components of the distance measuring device 1 described above may be Fig.13 The integrated control unit 7600 is implemented in a module (eg, an integrated circuit module configured by one die).

[0182] It should be noted that the present technology can adopt the following configurations.

[0183] (1) A distance measuring device that measures a distance to an object based on a reflected light signal received by a light receiving portion, the reflected light signal being generated when a light pulse signal emitted from a light emitting portion is reflected by the object, the distance measuring device comprising:

[0184] a first substrate formed of a Group IV material, the light receiving portion and the light emitting portion being integrally arranged on the first substrate; and

[0185] A second substrate is laminated on the first substrate, and a readout circuit for reading out a light reception signal received by the light receiving section is arranged on the second substrate.

[0186] (2) The distance measuring device according to (1), wherein:

[0187] The light receiving portion and the light emitting portion are integrally arranged on the first substrate.

[0188] (3) The distance measuring device according to (1) or (2), wherein:

[0189] The first substrate is a silicon substrate.

[0190] (4) The distance measurement device according to any one of (1) to (3), wherein:

[0191] The light emitting portion includes a compound semiconductor material or a mixed crystal of a compound semiconductor material.

[0192] (5) The distance measuring device according to (4), further comprising:

[0193] a buffer layer disposed on the first substrate and formed of a Group IV material different from a material of the first substrate, wherein

[0194] The light emitting portion is arranged on the buffer layer, and

[0195] The material of the buffer layer has a lattice spacing closer to the lattice spacing of the light emitting portion than the material of the first substrate.

[0196] (6) The distance measurement device according to any one of (1) to (5), wherein:

[0197] The light receiving section includes a photodiode, an avalanche photodiode, or a SPAD (Single Photon Avalanche Diode).

[0198] (7) The distance measurement device according to any one of (1) to (6), wherein:

[0199] When viewed in a plan view in a normal direction of a substrate surface of the first substrate, at least a portion of the light receiving portion overlaps with the readout circuit.

[0200] (8) The distance measurement device according to any one of (1) to (7), wherein:

[0201] The light emitting portion is arranged on the first substrate by selective epitaxial growth.

[0202] (9) The distance measurement device according to any one of (1) to (8), further comprising:

[0203] The light shielding member including a metal material is arranged between an arrangement region of the light receiving portion on the first substrate and an arrangement region of the light emitting portion on the first substrate.

[0204] (10) The distance measurement device according to any one of (1) to (9), wherein:

[0205] The light emitting portion is arranged along a surface of the first substrate opposite to a surface facing the second substrate.

[0206] (11) The distance measurement device according to any one of (1) to (9), wherein:

[0207] The light emitting portion is arranged inside the first substrate.

[0208] (12) The distance measurement device according to any one of (1) to (11), wherein:

[0209] The second substrate has a driving circuit that supplies a driving voltage to the light emitting portion.

[0210] (13) The distance measuring device according to (12), wherein:

[0211] When viewed in a plan view in a normal direction of a substrate surface of the first substrate, at least a portion of the light emitting portion overlaps with the driving circuit.

[0212] (14) The distance measuring device according to (13), further comprising:

[0213] A bonding member extends in the depth direction of the first substrate to connect the light emitting portion and the driving circuit, wherein:

[0214] When viewed in a plan view in a normal direction of a substrate surface of the first substrate, at least a portion of the bonding member is arranged in a region overlapping with the light emitting portion.

[0215] (15) The distance measuring device according to (13), further comprising:

[0216] A bonding member extends in the depth direction of the first substrate to connect the light emitting portion and the driving circuit, wherein:

[0217] When viewed in a plan view in a normal direction of a substrate surface of the first substrate, at least a portion of the bonding member is arranged in a region that does not overlap with the light emitting portion.

[0218] (16) The distance measuring device according to (12), wherein:

[0219] The drive circuit is arranged in a region that does not overlap with the light emitting portion when viewed in a plan view in a normal direction of a substrate surface of the first substrate.

[0220] (17) The distance measuring device according to any one of (1) to (16), wherein:

[0221] A portion of the circuit included in the readout circuit is arranged on the first substrate,

[0222] The light receiving section has a plurality of photoelectric conversion elements arranged in a two-dimensional direction, each of which receives light, and

[0223] The partial circuit has a plurality of pixel circuits connected to each of the plurality of photoelectric conversion elements.

[0224] (18) The distance measuring device according to any one of (1) to (17), wherein:

[0225] The first substrate has a light emitting portion and a light receiving portion arranged adjacent to each other,

[0226] Each light emitting section has a plurality of light emitting elements arranged close to each other, and

[0227] Each light receiving section has a plurality of photoelectric conversion elements arranged close to each other.

[0228] (19) The distance measuring device according to any one of (1) to (17), wherein:

[0229] The light emitting unit has a plurality of light emitting elements, and

[0230] The light receiving section has a plurality of light receiving elements which are arranged between the plurality of light emitting elements, arranged to surround the plurality of light emitting elements, or arranged to be surrounded by the plurality of light emitting elements.

[0231] (20) The distance measuring device according to any one of (1) to (19), wherein:

[0232] The light emitting part is VCSEL (Vertical Cavity Surface Emitting Laser).

[0233] (21) A method for manufacturing a distance measuring device, comprising:

[0234] forming a light receiving portion in a first region of a first substrate formed of a Group IV material;

[0235] forming a buffer layer formed of a Group IV material different from the material of the first substrate on the upper surface of the second region of the first substrate;

[0236] forming a light emitting portion formed of a compound semiconductor material on the buffer layer by selective epitaxial growth; and

[0237] A second substrate is bonded to the first substrate, the second substrate having a readout circuit for reading out a light reception signal received by the light reception section and a drive circuit for supplying a drive voltage to the light emission section.

[0238] Aspects of the present disclosure are not limited to the aforementioned embodiments, and include various modifications that can be implemented by those skilled in the art, and the effects of the present disclosure are not limited to the above details. In other words, various additions, modifications and partial deletions can be made without departing from the conceptual concept and gist of the present disclosure, and the conceptual concept and gist of the present disclosure can be derived from the details defined in the claims and their equivalents.

[0239] [Reference Numbers List]

[0240] 1 Distance measurement device

[0241] 2. Light-emitting part

[0242] 2a Light-emitting element

[0243] 2b Light-emitting element group

[0244] 3 Light receiving unit

[0245] 3a Photoelectric conversion element

[0246] 4. First substrate

[0247] 5 Second substrate

[0248] 6 Circuit

[0249] 7 Jointing components

[0250] 7a Jointing components

[0251] 7b Jointing components

[0252] 9. Driving Circuit

[0253] 10 Jointing components

[0254] 11. Lamination film

[0255] 12 Anode electrode

[0256] 13 Cathode electrode

[0257] 14 The first multilayer mirror

[0258] 14 The first multilayer mirror

[0259] 16 Active layer

[0260] 18 Second multilayer mirror

[0261] 21 first supporting substrate

[0262] 22. First semiconductor layer

[0263] 23. Second semiconductor layer

[0264] 25 Hard mask layer

[0265] 25a Opening

[0266] 26 Buffer layer

[0267] 27GaAs layer

[0268] 28 second supporting substrate

[0269] 29 Insulation layer

[0270] 30 Insulation layer

[0271] 31 Wiring Layer

[0272] 32 Insulation layer

[0273] 33 Groove

[0274] 40 Shading member

[0275] 41 Diffusion Zone

[0276] 50 objects

[0277] 51 Distance measurement unit

[0278] 52 Overall control unit

[0279] 53. Driving circuit

[0280] 54 Clock generation unit

[0281] 55 Lighting control unit

[0282] 60 pixels

[0283] 61 pixel array unit

[0284] 62 Distance measurement processing unit

[0285] 63 Control Unit

[0286] 64 clock generation units

[0287] 65. Lighting timing control unit

[0288] 66 drive circuit

[0289] 67 Output Buffer

[0290] 71 Time-to-digital converter (TDC)

[0291] 72 Histogram generation unit

[0292] 73 Signal Processing Unit

[0293] 74 Distance measurement control unit

Claims

1. A distance measuring device for measuring a distance to an object based on a reflected light signal received by a light receiving portion, the reflected light signal being generated when a light pulse signal emitted from a light emitting portion is reflected by the object, the distance measuring device comprising: a first substrate formed of a Group IV material, the light receiving portion and the light emitting portion being integrally arranged on the first substrate; as well as A second substrate is laminated on the first substrate, and a readout circuit for reading out a light reception signal received by the light receiving section is arranged on the second substrate.

2. The distance measuring device according to claim 1, wherein: The light receiving section and the light emitting section are integrally arranged on the first substrate.

3. The distance measuring device according to claim 1, wherein: The first substrate is a silicon substrate.

4. The distance measuring device according to claim 1, wherein: The light emitting portion includes a compound semiconductor material or a mixed crystal of the compound semiconductor material.

5. The distance measuring device according to claim 4, further comprising: a buffer layer disposed on the first substrate and formed of a Group IV material different from a material of the first substrate, wherein The light emitting portion is arranged on the buffer layer, and A material of the buffer layer has a lattice spacing closer to a lattice spacing of the light emitting portion than a material of the first substrate.

6. The distance measuring device according to claim 1, wherein: The light receiving section includes a photodiode, an avalanche photodiode, or a SPAD (Single Photon Avalanche Diode).

7. The distance measuring device according to claim 1, wherein: When viewed in a plan view in a normal direction of a substrate surface of the first substrate, at least a portion of the light receiving section overlaps with the readout circuit.

8. The distance measuring device according to claim 1, wherein: The light emitting portion is arranged on the first substrate by selective epitaxial growth.

9. The distance measuring device according to claim 1, further comprising: A light shielding member including a metal material is arranged between an arrangement region of the light receiving portion on the first substrate and an arrangement region of the light emitting portion on the first substrate.

10. The distance measuring device according to claim 1, wherein: The light emitting portion is arranged along a surface of the first substrate opposite to a surface facing the second substrate.

11. The distance measuring device according to claim 1, wherein: The light emitting portion is arranged inside the first substrate.

12. The distance measuring device according to claim 1, wherein: The second substrate has a driving circuit that supplies a driving voltage to the light emitting portion.

13. The distance measuring device according to claim 12, wherein: When viewed in a plan view in a normal direction of a substrate surface of the first substrate, at least a portion of the light emitting portion overlaps with the drive circuit.

14. The distance measuring device according to claim 13, further comprising: a bonding member extending in the depth direction of the first substrate to connect the light emitting portion and the driving circuit, wherein: When viewed in a plan view in the normal direction of a substrate surface of the first substrate, at least a portion of the bonding member is arranged in a region overlapping with the light emitting portion.

15. The distance measuring device according to claim 13, further comprising: a bonding member extending in the depth direction of the first substrate to connect the light emitting portion and the driving circuit, wherein: When viewed in a plan view in the normal direction of a substrate surface of the first substrate, at least a portion of the bonding member is arranged in a region that does not overlap with the light emitting portion.

16. The distance measuring device according to claim 12, wherein: The drive circuit is arranged in a region that does not overlap with the light emitting portion when viewed in a plan view in a normal direction of a substrate surface of the first substrate.

17. The distance measuring device according to claim 1, wherein: A portion of the circuit included in the readout circuit is arranged on the first substrate, The light receiving section has a plurality of photoelectric conversion elements arranged in a two-dimensional direction, each of the photoelectric conversion elements receiving light, and The partial circuit has a plurality of pixel circuits connected to each of the plurality of photoelectric conversion elements.

18. The distance measuring device according to claim 1, wherein: The first substrate has the light emitting sections and the light receiving sections arranged adjacent to each other, each of the light emitting sections has a plurality of light emitting elements arranged close to each other, and each of the light receiving sections has a plurality of photoelectric conversion elements arranged close to each other.

19. The distance measuring device according to claim 1, wherein: The light emitting unit has a plurality of light emitting elements, and The light receiving section has a plurality of light receiving elements, and the plurality of light receiving elements are arranged between the plurality of light emitting elements, arranged to surround the plurality of light emitting elements, or arranged to be surrounded by the plurality of light emitting elements.

20. The distance measuring device according to claim 1, wherein: The light emitting part is a VCSEL (Vertical Cavity Surface Emitting Laser).

21. A method for manufacturing a distance measuring device, comprising: forming a light receiving portion in a first region of a first substrate formed of a Group IV material; forming a buffer layer formed of a Group IV material different from the material of the first substrate on the upper surface of the second region of the first substrate; forming a light emitting portion formed of a compound semiconductor material on the buffer layer by selective epitaxial growth; as well as A second substrate is bonded to the first substrate, the second substrate having a readout circuit for reading out a light reception signal received by the light reception section and a drive circuit for supplying a drive voltage to the light emission section.

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