Distance measuring device

Abstract

A semiconductor device according to one aspect of the present disclosure includes a laminate in which a silicon photonic layer and a support substrate are bonded to each other. The silicon photon layer comprises a waveguide used for transmitting an optical signal; and a metal film provided facing the support substrate across the waveguide. The metal film includes a heater layer that can be used as a waveguide heater.

Description

Technical Field

[0001] This disclosure relates to a ranging device. Background Technology

[0002] In recent years, optical detection and ranging (LiDAR) systems that use photonic integrated circuits (PICs) to replace optical fibers have been developed, in which optical components such as Si waveguides are stacked on silicon-on-insulator (SOI) substrates (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-12136 Summary of the Invention

[0006] This system utilizes a phase shifter that leverages the thermo-optical effect in silicon photonics. For example, a phase shifter with a waveguide and heater layer stacked on an SOI substrate is used, and the phase of the optical signal propagating in the waveguide is modulated by applying heat generated in the heater layer to the waveguide, thereby changing the refractive index of the waveguide through the thermo-optical effect. Further improvements in the power efficiency of the phase shifter are desired. It is desirable to provide semiconductor devices and ranging devices capable of improving the power efficiency of the phase shifter.

[0007] A semiconductor device according to an embodiment of the present disclosure includes a stack comprising a silicon photonic layer and a support substrate bonded together. The silicon photonic layer includes a waveguide through which optical signals are transmitted; and a metal film disposed opposite to the support substrate across the waveguide. The metal film includes a heater layer configured to function as a waveguide heater.

[0008] A ranging device according to an embodiment of the present disclosure includes: a light source chip for outputting an optical signal; and a silicon photonics layer including: a waveguide through which the optical signal output from the light source chip is transmitted; and a detector configured to detect the signal guided through the waveguide. Furthermore, the ranging device further includes: a support substrate attached to the silicon photonics layer; and a signal processing substrate for processing the signal detected by the detector. The silicon photonics layer includes: a waveguide through which the optical signal is transmitted; and a metal film disposed opposite to the support substrate across the waveguide. The metal film includes a heater layer configured to function as a waveguide heater.

[0009] In the semiconductor device and ranging device according to embodiments of the present disclosure, a silicon photonic layer and a support substrate are bonded together, and a heater layer, configured as a heater for a waveguide, is disposed opposite to the support substrate across the waveguide. Thus, compared to a phase shifter where the waveguide and heater layer are stacked on an SOI substrate, the heater layer is disposed at a position far from the support substrate. Furthermore, a waveguide exists in the heat transfer path from the heater layer to the support substrate. As a result, heat generated in the heater layer can be efficiently transferred to the waveguide, thereby improving the power efficiency of the phase shifter. Attached Figure Description

[0010] Figure 1 This is a diagram illustrating a schematic configuration example of a ranging device according to an embodiment of the present disclosure.

[0011] Figure 2 It is shown Figure 1 An example diagram of the cross-sectional configuration of the PIC substrate shown.

[0012] Figure 3 It is shown Figure 1 An example diagram showing a cross-sectional configuration of the PIC substrate.

[0013] Figure 4 It is shown in Figure 1 The diagram shows an example of a schematic configuration of the antenna.

[0014] Figure 5 It is shown in Figure 1 A diagram illustrating a schematic configuration example of the coupler and detector is shown.

[0015] Figure 6 It is shown Figure 5 A perspective view of an example detector configuration shown in the figure.

[0016] Figure 7A It is used to explain the use of manufacturing in Figure 1 A cross-sectional view of the method for using a PIC substrate is shown in the figure.

[0017] Figure 7B It is used to explain from Figure 7A Cross-sectional view of the continued manufacturing method.

[0018] Figure 7C It is used to explain from Figure 7B Cross-sectional view of the continued manufacturing method.

[0019] Figure 7D It is used to explain from Figure 7C Cross-sectional view of the continued manufacturing method.

[0020] Figure 8 It shows Figure 6A diagram illustrating a modified example of the cross-sectional configuration of the PIC substrate shown.

[0021] Figure 9 It shows Figure 6 A diagram illustrating a modified example of the cross-sectional configuration of the PIC substrate shown.

[0022] Figure 10 It shows Figure 9 A diagram illustrating a modified example of the planar configuration of the groove portion shown.

[0023] Figure 11 It shows Figure 6 A diagram illustrating a modified example of the cross-sectional configuration of the PIC substrate shown.

[0024] Figure 12 It shows Figure 6 A diagram illustrating a modified example of the cross-sectional configuration of the PIC substrate shown.

[0025] Figure 13 It is shown Figure 5 A diagram illustrating a modified example of the cross-sectional configuration of the PIC substrate shown.

[0026] Figure 14 It shows Figure 6 A diagram illustrating a modified example of the cross-sectional configuration of the PIC substrate shown.

[0027] Figure 15 It is shown Figure 6 A diagram illustrating a modified example of the cross-sectional configuration of the PIC substrate shown.

[0028] Figure 16 It is shown Figure 6 A diagram illustrating a modified example of the cross-sectional configuration of the PIC substrate shown.

[0029] Figure 17 It is a block diagram illustrating an example of a schematic configuration of a vehicle control system.

[0030] Figure 18 This is an illustration showing an example of the installation location of the vehicle exterior information detection unit and the imaging unit. Detailed Implementation

[0031] The following description, with reference to the accompanying drawings, details the model used to implement this disclosure. It should be noted that the description is given in the following order.

[0032] 1. Implementation Method

[0033] Example of a support substrate being bonded to a PIC layer ( Figures 1 to 7D )

[0034] 2. Variations

[0035] Variation Example 2-1: Example of setting up a heat dissipation layer and trenches ( Figure 8 )

[0036] Variation Example 2-2: An example of a waveguide surrounded by a trench from three directions ( Figure 9 and Figure 10 )

[0037] Variation Example 2-3: Example where the heat dissipation part is located on the bottom surface of the recess ( Figure 11 )

[0038] Variation 2-4: An example of setting up a pair of heaters in a way that clamps the waveguide ( Figure 12 )

[0039] Variation Example 2-5: Example of bonding a signal processing substrate to a PIC layer ( Figure 13 and Figure 14 )

[0040] Variation 2-6: Example of a laser chip mounted on a signal processing substrate ( Figure 15 )

[0041] Variation 2-7: Example of a signal processing substrate mounted on a PIC layer ( Figure 16 )

[0042] 3. Application examples ( Figure 17 and Figure 18 )

[0043] <1. Implementation Method>

[0044] <Construction>

[0045] Figure 1 A schematic configuration example of a ranging device 1000 according to an embodiment of the present disclosure is shown. The ranging device 1000 is a frequency-modulated continuous wave (FMCW) LiDAR. In an FMCW LiDAR, laser light (emitted signal) that has been modulated so that its frequency increases linearly with time is continuously emitted, and the distance is determined by the frequency difference between the emitted signal and the reflected light (return signal).

[0046] Distance measuring device 1000, for example, such as Figure 1 As shown, it includes a PIC substrate 100, a laser chip 200, and a signal processing substrate 300.

[0047] <Laser Chip 200>

[0048] The laser chip 200 is a light source chip that outputs an optical signal. The laser chip 200 is a compound semiconductor used as an edge-emitting light source and is configured to emit a laser L (optical signal) of a predetermined fixed wavelength (e.g., 1550 nm) under the control of a controller 310 described later. The compound semiconductor used as a light source includes, for example, an active layer that amplifies light and a diffraction grating layer for laser oscillation. The compound semiconductor used as a light source is configured to emit the laser L toward the PIC substrate 100 (Si layer 521 described later). In addition, the compound semiconductor used as a light source may be a semiconductor optical amplifier (SOA) that only has a light amplification function, and a resonator for laser oscillation may be formed on the side surface of the PIC substrate 100 that is optically coupled to the laser chip 200.

[0049] <PIC substrate 100>

[0050] The PIC substrate 100 includes, for example, as Figure 1 shown, a modulator 110, a splitter 120, a circulator 130, an antenna 140, a coupler 150, and a detector 160. In the PIC substrate 100, the modulator 110, the splitter 120, the circulator 130, the antenna 140, the coupler 150, and the detector 160 are formed in the PIC layer 20 described later.

[0051] Figure 2 and Figure 3 shows an example of the cross-sectional configuration of the PIC substrate 100. Figure 2 shows an example of the cross-sectional configuration of a specific part of the PIC substrate 100; Figure 3 shows the PIC substrate 100 in relation to Figure 2 a different part. For example, as Figure 2 and Figure 3 shown, the PIC substrate 100 is a stack including a silicon photon layer 520 and a support substrate 510 bonded to each other. For example, the support substrate 510 is a semiconductor substrate such as a Si substrate.

[0052] For example, as Figure 2 and Figure 3 shown, the silicon photon layer 520 includes a Si layer 521, an interlayer insulating film 522, and a BOX (buried oxide) layer 523 sandwiching the Si layer 521. For example, as Figure 2 and Figure 3As shown, the silicon photonic layer 520 further includes a SiN layer 525 disposed in the interlayer insulating film 522 and an interlayer insulating film 524 in contact with the BOX layer 523. The SiN layer 525 is disposed in a layer different from the Si layer 521. The silicon photonic layer 520 includes a stack (Si layers 521 and 525, interlayer insulating film 522 and BOX layer 523) obtained by removing the Si substrate 620 from the PIC substrate 600 described later.

[0053] BOX layer 523 includes a SiO2 layer. Interlayer insulating film 522 has a configuration in which patterned wiring layers and vias coupling the wiring layers are formed in the stacked SiO2 layers. In interlayer insulating film 522, for example, as... Figure 2 and Figure 3 As shown, wiring (e.g., wiring 540 and 550) including wiring layers and vias are provided, and a SiN layer 525 and a GePD layer 526 are further provided. The surface of the interlayer insulating film 522 serves as the bottom surface of the silicon photonics layer 520. The surface of the interlayer insulating film 522 is in contact with the surface of the support substrate 510, and the bonding surface of the interlayer insulating film 522 and the support substrate 510 serves as interface S1. The interlayer insulating film 524 has a configuration in which a plurality of patterned wiring layers and vias coupling the wiring layers are formed in a plurality of SiO2 layers stacked on top of each other. In the interlayer insulating film 524, for example, as Figure 2 and Figure 3 As shown, wiring (e.g., wiring 530, 560, 570, and 580) is provided, each including a wiring layer and vias. Wiring 530, 560, 570, and 580 are formed, for example, using metallic materials such as copper, tungsten, gold, platinum, cobalt, or ruthenium.

[0054] In the interlayer insulating film 522, for example, as Figure 2 and Figure 3 As shown, a heater layer 142b is provided, coupled to wiring including a wiring layer and vias. The heater layer 142b is coupled to wiring 540. In the interlayer insulating film 524, for example, as... Figure 2 and Figure 3 As shown, heater layers 142a, 142c, and 142d are provided, each coupled to a wiring layer and a via. Heater layer 142a is coupled to wiring 530. Heater layer 142c is coupled to wiring 570. Heater layer 142d is coupled to wiring 580.

[0055] Heater layers 142a, 142b, 142c, and 142d are positioned at different locations in the plan view. Heater layer 142a is positioned in a location not opposite to heater layers 142b, 142c, and 142d in the plan view. Heater layer 142b is positioned in a location not opposite to heater layers 142a, 142c, and 142d in the plan view. Heater layer 142c is positioned in a location not opposite to heater layers 142a, 142b, and 142d in the plan view. Heater layer 142d is positioned in a location not opposite to heater layers 142a, 142b, and 142c in the plan view.

[0056] In interlayer insulating films 522 and 524, for example, as Figure 2 As shown, a wiring 560 coupled to wiring 550 is provided. Wiring 560 includes, for example, a via 561 coupled to wiring 550 and a wiring layer 562 coupled to via 561. In interlayer insulating films 522 and 524, for example, as Figure 3 As shown, a wiring 590 is provided with coupling wiring 540. For example, wiring 590 includes a via 591 coupling wiring 540 and a wiring layer 592 coupling via 591. Wiring 590 is made of metallic materials such as copper, tungsten, gold, molybdenum, cobalt, and ruthenium.

[0057] Si layer 521 is provided with, for example Figure 1 Optical waveguides WG1, WG2, and WG3 are shown. Optical waveguides WG1, WG2, and WG3 allow the transmission of optical signals. Optical waveguide WG1 extends from one end of the PIC layer 520 through modulator 110, beam splitter 120, and circulator 130 to antenna 140. Optical waveguide WG2 is a branch of optical waveguide WG1 at beam splitter 120 and is coupled to one input port of coupler 150 (optical waveguide 151, described later). Optical waveguide WG3 is a branch of optical waveguide WG1 at circulator 130 and is coupled to the other input port of coupler 150 (optical waveguide 152, described later). Laser L emitted from laser chip 200 enters optical waveguide WG1. Laser L propagating through optical waveguide WG1 is input to modulator 110.

[0058] Modulator 110 is configured to modulate the frequency of laser L according to the control of controller 310. For example, modulator 110 is configured to modulate laser L such that the frequency increases linearly with time, and then modulate laser L such that the frequency decreases linearly with time. For example, modulator 110 is configured to periodically repeat this linear increase and decrease of frequency, and outputs the transmitted signal Stx generated therethrough to beam splitter 120 via optical waveguide WG1. The transmitted signal Stx is a chirped signal obtained by frequency modulation of laser L by modulator 110. Optical waveguide WG1 allows the transmission of the chirped signal. Modulator 110 is formed, for example, in Si layer 521. Modulator 110 is formed, for example, using a Mach-Zehnder interferometer in which the Si waveguide branches into two. In this case, modulator 110 forms a PN junction in one of the branched waveguides and applies an alternating voltage waveform to the PN junction, which changes the refractive index due to carrier-plasma effects, thereby enabling the generation of a phase-changing signal of light. Modulator 110 combines the waveforms of the generated signal and the original signal at the output of the interferometer, thereby enabling modulation of the phase of the original signal.

[0059] The beam splitter 120 divides the transmitted signal Stx into a transmitted signal Stx1 (for transmission to the target TG) and a transmitted signal Stx2 (for interference with the returned signal Srx in the coupler 150). Transmitted signal Stx1 has most of the energy of transmitted signal Stx. Transmitted signal Stx2 is a reference signal with significantly less energy than transmitted signal Stx1, but still sufficient to allow it to interfere with the returned signal Srx in the coupler 150. The returned signal Srx is equivalent to a signal with a phase delay relative to transmitted signal Stx1. The returned signal Srx is generated from the transmitted signal Stx reflected from the target TG.

[0060] Optical splitter 120 is a three-port device. In optical splitter 120, a first port and a third port are located in optical waveguide WG1. A second port is located in optical waveguide WG2. Optical waveguide WG2 is positioned adjacent to the portion between the first and third ports in optical waveguide WG1. Thus, optical signals propagating through optical waveguide WG1 leak into optical waveguide WG2. The optical signal leaking from optical waveguide WG1 into optical waveguide WG2 propagates through optical waveguide WG2 as a transmitted signal Stx2. Optical waveguide WG2 allows the transmission of the transmitted signal Stx2.

[0061] Circulator 130 is a three-port device configured to transmit a transmit signal Stx1 input from the first port to the third port and a return signal Srx input from the third port to the second port. In circulator 130, optical waveguide WG1 is coupled to the first port, and optical waveguide WG2 is coupled to the second port. An optical waveguide extending from antenna 140 is coupled to the third port. Circulator 130 is used, for example, to rectify the transmitted optical signal and the optical signal received from antenna 141. The same circuitry as coupler 150 can be used in circulator 130; in this case, due to the structure of the optical waveguide with Si branches, the signal strengths of the transmitted and received signals are split into 50% / 50% in the branches. By processing this half-signal, the transmitted and received light can be separated.

[0062] Antenna 140 has the function of radiating a signal of light guided by a waveguide into free space and receiving a signal from free space. Antenna 140 may function as, for example, a mechanical scanner without a drive unit. Antenna 140 is configured to transmit a transmit signal Stx1 to a target TG, for example, through a lens, and to receive a return signal Srx, for example, through a lens. The lens is attached to a region (incident / exit surface) on the surface of the PIC substrate 100 opposite to antenna 141. The transmit signal Stx1 is output from the incident / exit surface, and the return signal Srx enters the incident / exit surface. For example, the lens is bonded to the incident / exit surface, and the transmit signal Stx is output from antenna 140 to the outside through the lens and the incident / exit surface, while the return signal Srx is input from the outside to antenna 140 through the lens and the incident / exit surface.

[0063] For example, such as Figure 4 As shown, antenna 140 includes a plurality of (e.g., four) antenna bodies, each antenna body including an antenna 141 and a heater layer 142 disposed opposite to the antenna 141. The individual antenna bodies extend in a common direction, and the plurality of antenna bodies are arranged at predetermined intervals in a direction perpendicular to the extension direction of the antenna bodies.

[0064] Here, it is assumed that four antenna bodies are provided. In this case, antenna 141 includes, for example, two Si waveguides 141a and 141b disposed in Si layer 521 and two SiN waveguides 141c and 141d disposed in SiN layer 525. That is, antenna 141 has, for example, Si waveguides 141a and 141b and SiN waveguides 141c and 141d made of different materials. Si waveguides 141a and 141b have, for example, diffraction gratings disposed in Si layer 521. SiN waveguides 141c and 141d include, for example, diffraction gratings disposed in SiN layer 525.

[0065] A diffraction grating is, for example, a device in which multiple grooves or vias are arranged on a Si layer 521 at a spacing of several hundred nm. Antenna 141 is configured, under the control of controller 310, to output a transmission signal Stx1 at a predetermined angle to the surface of Si layer 521, which has a peak at a specific point according to the spacing of the diffraction grating.

[0066] Heater layer 142 is a metal film configured to function as a heater for waveguide WG1. Heater layer 142 includes, for example, heater layer 142a arranged to be spaced apart from Si waveguide 141a (waveguide WG1) by a predetermined gap, and heater layer 142b arranged to be spaced apart from Si waveguide 141b (waveguide WG1) by a predetermined gap. Heater layer 142 also includes, for example, heater layer 142c arranged to be spaced apart from SiN waveguide 141c (waveguide WG1) by a predetermined gap, and heater layer 142d arranged to be spaced apart from SiN waveguide 141d (waveguide WG1) by a predetermined gap. Heater layer 142a is, for example, a resistive element extending along Si waveguide 141a. Heater layer 142b is, for example, a resistive element extending along Si waveguide 141b. Heater layer 142c is, for example, a resistive element extending along SiN waveguide 141c. The heater layer 142d is, for example, a resistive element extending along the SiN waveguide 141d.

[0067] For example, materials such as TiN, W, HfOx, ITO, or IGZO are used to form the heater layers 142 (142a, 142b, 142c, and 142d). The wiring layers in the interlayer insulating films 522 and 524 have a lower resistivity than the heater layers 142 (142a, 142b, 142c, and 142d). When the interlayer insulating films 522 and 524 and the wiring layers in the heater layers 142 (142a, 142b, 142c, and 142d) are made of the same material, the film thickness of the wiring layers in the interlayer insulating films 522 and 524 is greater than the film thickness of the heater layers 142 (142a, 142b, 142c, and 142d).

[0068] Heater layer 142a is configured to heat Si waveguide 141a by applying current to a resistive element according to control from controller 310, thereby heating the resistive element. In Si waveguide 141a, the refractive index changes due to the heat applied by heater layer 142a, and a transmission signal Stx1 is output at an angle corresponding to the change in refractive index. Heater layer 142b is configured to heat Si waveguide 141b by applying current to a resistive element according to control from controller 310, thereby heating the resistive element. In Si waveguide 141b, the refractive index changes due to the heat applied by heater layer 142b, and a transmission signal Stx1 is output at an angle corresponding to the change in refractive index.

[0069] Heater layer 142c is configured to heat SiN waveguide 141c by applying current to a resistive element to heat the resistive element, according to control from controller 310. In SiN waveguide 141c, the heat applied by heater layer 142c changes the refractive index, and a transmission signal Stx1 is output at an angle according to the change in refractive index. Heater layer 142d is configured to heat SiN waveguide 141d by applying current to a resistive element to heat the resistive element, according to control from controller 310. In SiN waveguide 141d, the refractive index is changed by the heat applied by heater layer 142d, and a transmission signal Stx1 is output at an angle according to the change in refractive index. That is, antenna 141 is configured to scan and transmit signal Stx1 in a predetermined area externally according to control from controller 310.

[0070] Here, heater layer 142a is disposed within interlayer insulating film 524 and positioned opposite the support substrate 510, separated by Si waveguide 141a. The distance between heater layer 142a and Si waveguide 141a is d1. Heater layer 142b is disposed within interlayer insulating film 522 and positioned opposite the support substrate 510, separated by wiring 540. Heater layer 142b is disposed between Si waveguide 141b and support substrate 510. The distance between heater layer 142b and Si waveguide 141b is d3. Distance d3 can be equal to or different from distance d1. Heater layer 142c is disposed within interlayer insulating film 524 and positioned opposite the support substrate 510, separated by SiN waveguide 141c. The distance between heater layer 142c and SiN waveguide 141c is d2. Heater layer 142d is disposed within interlayer insulating film 524 and positioned opposite to support substrate 510, separated by SiN waveguide 141d. The distance between heater layer 142d and SiN waveguide 141d is d2. Distance d2 is different from distances d1 and d3. Heater layers 142b, 142c, and 142d are disposed in different layers from each other. Heater layers 142a, 142c, and 142d can be disposed in the same layer or in different layers.

[0071] In the case of setting up four antenna bodies, for example, as Figure 4 As shown, the antenna 140 further includes four optical switches 143 (one for each antenna body) and two optical switches 144 (one for every two optical switches 143). Each optical switch 143 is a switch for connecting and disconnecting the optical waveguide between two terminals (the first terminal and the second terminal). Each optical switch 144 is a switch for connecting and disconnecting the optical waveguide between two terminals (the third terminal and the fourth terminal). For example, as... Figure 4As shown, antenna 140 further includes an optical switch 145 coupled to two optical switches 144. Each optical switch 145 is a switch for connecting and disconnecting the optical waveguide between two terminals (terminal 5 and terminal 6).

[0072] In each optical switch 143, a first terminal is coupled to the antenna body, and a second terminal is coupled to the second terminal of another optical switch 143 and the third terminal of optical switch 144. In each optical switch 144, a third terminal is coupled to the second terminals of both optical switches 143, and a fourth terminal is coupled to the fourth terminal of another optical switch 144 and the fifth terminal of optical switch 145. In optical switch 145, a fifth terminal is coupled to the fourth terminals of both optical switches 144, and a sixth terminal is coupled to the second port of circulator 130.

[0073] The antenna body includes, for example, a diffraction grating disposed in a Si layer 521. The diffraction grating is, for example, a device consisting of multiple slots arranged in a row in the Si layer 521 at a spacing of several hundred nm. The depth of the slots is, for example, several hundred nm, and the thickness of the portion of the Si layer 521 corresponding to the diffraction grating substrate is, for example, several hundred nm.

[0074] In antenna 141, a transmitted signal Stx1, which has a peak at a specific point, is output to the surface of Si layer 521 at a predetermined angle, depending on the spacing of the diffraction grating. Heater layer 142 is a resistive element extending along antenna 141. Heater layer 142 heats antenna 141 by causing the resistive element to heat up with current applied to it according to control from controller 310. In antenna 141, the refractive index is changed by the heat applied by heater layer 142, and the transmitted signal Stx1 is output at an angle according to the change in refractive index.

[0075] For example, antenna 140 is configured to turn four optical switches 143, two optical switches 144, and one optical switch 145 on / off according to control from controller 310. Thus, antenna 140 is configured to output a transmit signal Stx1 from each antenna body in a predetermined direction and receive a return signal Srx input from an external source.

[0076] Coupler 150 is a device that generates a beat frequency signal Sbt due to interference between the transmitted signal Stx2 and the returned signal Srx. The frequency of the beat frequency signal Sbt changes according to the frequency difference between the transmitted signal Stx2 and the returned signal Srx. The frequency difference changes according to the distance from antenna 141 to the target TG. Therefore, the distance from antenna 141 to the target TG can be estimated based on the frequency of the beat frequency signal Sbt.

[0077] For example, such as Figure 5As shown, coupler 150 includes an optical waveguide 151 for propagating the transmitted signal Stx2 and an optical waveguide 152 for propagating the returned signal Srx. Optical waveguides 151 and 152 are, for example, ribbed waveguides. Optical waveguides 151 and 152 are arranged such that their portions are adjacent to each other, causing the transmitted signal Stx2 propagating in optical waveguide 151 and the returned signal Srx propagating in optical waveguide 152 to interfere with each other, thereby generating a beat frequency signal Sbt.

[0078] Detector 160 is a device that extracts the beat frequency signal Sbt from the signals propagating through optical waveguides 151 and 152 under the control of controller 310. For example, as... Figure 6 As shown, detector 160 includes GePDs 161 and 162 coupled in series with each other and a transimpedance amplifier 163 coupled to the coupling node of GePDs 161 and GePDs 162.

[0079] GePDs 161 and 162 are detectors configured to detect signals guided through optical waveguides 151 and 152. For example, as Figure 5 As shown, GePD 161 is a PIN photodiode coupled to optical waveguide 151. For example, as Figure 5 As shown, GePD 162 is a PIN photodiode coupled to optical waveguide 152. GePDs 161 and 162 include, for example, a Si platform 61 coupled to optical waveguides 151 and 152 and a p-type Si layer 62 formed by implanting B ions into the Si platform 61. The Si platform 61 and optical waveguides 151 and 152 are formed in a common Si layer 521.

[0080] GePDs 161 and 162 also include, for example, an island-shaped i-type Ge layer 63 and a two-dimensionally grown i-type Ge layer 64 formed on a p-type Si layer 62, and an n-type Ge layer 65 formed by implanting P ions into the two-dimensionally grown i-type Ge layer 64. A PIN photodiode is formed by stacking the p-type Si layer 62, the island-shaped i-type Ge layer 63, the two-dimensionally grown i-type Ge layer 64, and the n-type Ge layer 65. In this PIN photodiode, the island-shaped i-type Ge layer 63, which becomes an effective p-type layer and does not form a depletion layer therein, is thin, while the thick two-dimensionally grown i-type Ge layer 64 becomes a depletion layer, thus improving sensitivity.

[0081] GePDs 161 and 162 further include, for example, an n-side electrode 66 in contact with an n-type Ge layer 65 and a p-side electrode 67 in contact with a p-type Si layer 62. The p-side electrode 67 of GePD 161 and the n-side electrode 66 of GePD 162 are coupled by wiring, and the wiring coupling the p-side electrode 67 of GePD 161 and the n-side electrode 66 of GePD 162 is coupled to the input port of the transimpedance amplifier 163.

[0082] Transimpedance amplifier 163 performs impedance transformation on the current signal photoelectrically converted by GePD 161 and 162 and amplifies the current signal, and outputs a beat frequency signal Sbt as a voltage signal.

[0083] In the interlayer insulating film 524, for example, as Figure 2 and Figure 3 As shown, openings H1, H2, H3, H4, and H5, and a recess 524A are formed. Wiring 530 is exposed on the bottom surface of opening H1. Wiring 560 is exposed on the bottom surface of opening H2. Wiring 570 is exposed on the bottom surface of opening H3. Wiring 580 is exposed on the bottom surface of opening H4. Wiring 590 is exposed on the bottom surface of opening H5. Recess 524A is provided at a position opposite to the Si waveguide 141b, and the bottom surface of recess 524A is provided at a predetermined distance from the Si waveguide 141b. Recess 524A is a heat dissipation control part provided at a position opposite to the heater layer 142b across the Si waveguide 141b. Recess 524A is a structure for controlling the heat dissipation in the path (hereinafter referred to as the "heat dissipation path of heater layer 142b") through the Si waveguide 141b from the surface of the interlayer insulating film 524. By providing a recess 524A on the interlayer insulating film 524, the heat dissipation in the heat dissipation path of the heater layer 142b is reduced due to the thermal insulation of the air gap (air) in the recess 524A.

[0084] <Signal Processing Board 300>

[0085] The signal processing substrate 300 is a substrate configured to process signals detected by the PIC substrate 100 (e.g., GePD 161 and 162) and control the heater layer 142. For example, as Figure 1 As shown, the signal processing board 300 includes a controller 310, a DAC 320, an ADC 330, and an FFT (Fast Fourier Transform) 340.

[0086] Controller 310 is configured to generate, for example, control signals for controlling laser 210, modulator 110, antenna 140, and detector 160, and output these control signals to DAC 320. Controller 310 is further configured to generate, for example, control signals for controlling ADC 330, and output these control signals to ADC 330. DAC 320 is configured to convert the control signals input from controller 310 from digital to analog and output the analog control signals to laser 210, modulator 110, antenna 140, and detector 160. ADC 330 is configured to convert the beat frequency signal Sbt input from detector 160 from analog to digital and output the digital beat frequency signal Sbt to FFT 340. FFT 340 is configured to perform an FFT on the digital beat frequency signal Sbt input from ADC 330 and derive the frequency of the beat frequency signal Sbt from the resulting power spectral density. FFT 340 is configured to output information about the derived frequency (frequency information) to controller 310. The controller 310 is configured to output frequency information input from the FFT 340 to the outside based on control from the outside.

[0087] The signal processing substrate 300 includes, for example, a Si substrate. Signal processing circuitry, such as a controller 310, a DAC 320, an ADC 330, and an FFT 340, is formed on the Si substrate. An interlayer insulating film is formed on the Si substrate in the signal processing substrate 300. This interlayer insulating film is constructed such that multiple patterned wiring layers and vias for coupling wiring layers are formed in multiple SiO2 layers stacked on top of each other. Wiring and vias for the signal processing circuitry, wiring and vias for electrically coupling the signal processing circuitry to the PIC substrate 100 and the laser chip 200, etc., are formed in the interlayer insulating film.

[0088] <Manufacturing Method>

[0089] Next, the method for manufacturing the ranging device 1000 will be described.

[0090] Figures 7A to 7D This is a cross-sectional view used to illustrate the process of manufacturing the ranging device 1000. First, the PIC substrate 600 is prepared. Figure 7A The PIC substrate 600 is a substrate on which a BOX layer 523, a Si layer 521, a SiN layer 525, and an interlayer insulating film 522 are formed on a Si substrate 620. Next, the PIC substrate 600 is bonded to the signal processing substrate 300 such that the surface of the interlayer insulating film 522 and the surface of the support substrate 510 are opposite to each other. Figure 7A and Figure 7B Next, the Si substrate 620 in the PIC substrate 600 is removed. Figure 7C This exposes BOX layer 523.

[0091] Next, an interlayer insulating film 524a is formed on the BOX layer 523, and thereafter, predetermined trenches are formed in the interlayer insulating film 524a, the BOX layer 523, and the interlayer insulating film 522, and a film of metallic material is formed to bury the formed trenches, thereby forming wirings 530, 570, 580, and 590. Figure 7D Then, an interlayer insulating film is formed on the entire surface including the interlayer insulating film 524a, thereby forming the interlayer insulating film 524. Openings H1, H3, H4, and H5 are then formed at predetermined locations on the interlayer insulating film 524. Therefore, wirings 530, 560, 570, 580, and 590 are exposed on the bottom surfaces of the openings H1, H3, H4, and H5. Furthermore, recesses 524A are formed at predetermined locations on the interlayer insulating film 524. Then, for example, wire bonding is performed on the wirings 530, 560, 570, 580, and 590 through the openings H1, H3, H4, and H5, thereby electrically coupling the PIC layer 520 and the signal processing substrate 300. In this manner, the ranging device 1000 is manufactured.

[0092] <Effect>

[0093] Next, the effect of the ranging device 1000 will be described.

[0094] In this embodiment, the silicon photonic layer 520 and the support substrate 510 are bonded together, and the heater layers 142a, 142c, and 142d, configured as waveguide WG1, are disposed opposite to the support substrate 510 across the waveguide WG1. Thus, compared to a phase shifter that stacks waveguides and heater layers on an SOI substrate, the heater layers 142a, 142c, and 142d are positioned away from the support substrate 510. Furthermore, the waveguide WG1 exists in the heat propagation path from the heater layers 142a, 142c, and 142d to the support substrate 510. As a result, the heat generated in the heater layers 142a, 142c, and 142d can be effectively propagated to the waveguide, and the proportion of heat propagating to the support substrate 510 can be reduced. Therefore, the power efficiency of the phase shifter can be improved.

[0095] In this embodiment, the silicon photonic layer 520 is provided with heater layers 142a and 142b, and heater layers 142c and 142d. Heater layers 142a and 142b are respectively separated from Si waveguides 141a and 141b by predetermined gaps d1 and d3, and heater layers 142c and 142d are respectively separated from SiN waveguides 141c and 141d by predetermined gaps d2. Here, the appropriate lengths of the distance between Si waveguide 141a and heater layer 142a, the appropriate lengths of the distance between Si waveguide 141b and heater layer 142b, and the appropriate lengths of the distances between SiN waveguides 141c and 141d and heater layers 142c and 142d are different from each other. Therefore, in the silicon photonic layer 520, for example, heater layers 142a, 142b, 142c, and 142d are disposed in different layers from each other, and gaps d1, d2, and d3 are independently controlled. Thus, considering power efficiency and losses, the aforementioned gaps can be made to have appropriate lengths. Therefore, the power efficiency of the phase shifter can be improved.

[0096] In this embodiment, a heater layer 142b is disposed between the Si waveguide 141b and the support substrate 510, and the heater layer 142b is positioned in a position not opposite to the other heater layers 142a, 142c, and 142d in the plan view. Therefore, the Si waveguide 141b disposed in the position opposite to the heater layer 142b is heated primarily by heat radiated from the heater layer 142b, and the heat radiated from the other heater layers 142a, 142c, and 142d has a relatively small impact on the Si waveguide 141b. Therefore, the Si waveguide 141b can be independently controlled by the heater layer 142b.

[0097] In this embodiment, the recess 524A is provided as a heat dissipation control unit at a position opposite to the heater layer 142b, separated by the Si waveguide 141b. Therefore, due to the thermal insulation of the air gap (air) in the recess 524A, heat dissipation in the heat dissipation path of the heater layer 142b is reduced. As a result, the power efficiency of the phase shifter including the heater layer 142b and the Si waveguide 141b can be improved.

[0098] <2. Variations>

[0099] Subsequently, a modified example of the ranging device 1000 according to the above embodiment is described.

[0100] <Variation Example 2-1>

[0101] Figure 8 An example of the cross-sectional configuration of the ranging device 1000 according to a modified example is shown. In the above embodiment, for example, as Figure 8As shown, a heat dissipation layer 630 can be provided at a position opposite to the heater layer 142b, separated from the Si waveguide 141a. The heat dissipation layer 630 is, for example, a metal film independent of the circuit wiring. For example, the heat dissipation layer 630 can be formed using a metal material such as copper, tungsten, gold, platinum, cobalt, or ruthenium. For example, the heat dissipation layer 630 can be formed using materials such as TiN, W, HfOx, ITO, or IGZO. In this way, by providing the heat dissipation layer 630 at a position opposite to the heater layer 142b, separated from the Si waveguide 141a, heat dissipation in the heat dissipation path of the heater layer 142a can be adjusted. As a result, the power efficiency and thermal response of the phase shifter can be adjusted.

[0102] <Variation Example 2-2>

[0103] Figure 9 An example of the cross-sectional configuration of the ranging device 1000 according to a modified example is shown. In the above embodiment, for example, as Figure 9 As shown, a trench portion 524B can be provided instead of a recess 524A. The trench portion 524B has a depth reaching the Si waveguide 141b, and for example, as... Figure 9 and Figure 10 As shown, the bottom surface of the trench portion 524B is formed into a convex shape (protrusion 524C) surrounding the three sides of the Si waveguide 141b (the surface on the side opposite to the heater layer 142b and the two side surfaces). It should be noted that... Figure 10 An example of a planar configuration of the bottom surface of the trench portion 524B is shown. As a result, due to the thermal insulation of the gaps (air) in the trench portion 524B, heat dissipation in the heat dissipation path of the heater layer 142b is reduced. Consequently, the power efficiency of the phase shifter, including the heater layer 142b and the Si waveguide 141b, can be improved.

[0104] <Variation Example 2-3>

[0105] Figure 11 An example of the cross-sectional configuration of the ranging device 1000 according to a modified example is shown. In the above embodiment, for example, as Figure 11 As shown, a heat dissipation portion 524D, which is a metal film independent of the circuit wiring, can be provided on the bottom surface of the recess 524A. For example, the surface of the heat dissipation portion 524D has multiple protrusions and recesses. The heat dissipation portion 524D is formed using, for example, a metallic material such as copper, tungsten, gold, platinum, cobalt, or ruthenium. The heat dissipation portion 524D can also be formed using, for example, materials such as TiN, W, HfOx, ITO, or IGZO. In this way, by providing the heat dissipation portion 524D on the bottom surface of the recess 524A, the heat dissipation in the heat dissipation path of the heater layer 142b can be adjusted. As a result, the power efficiency and thermal response of the phase shifter can be adjusted.

[0106] <Variation Example 2-4>

[0107] Figure 12 An example of the cross-sectional configuration of the ranging device 1000 according to a modified example is shown. In the above embodiments and their modifications, for example, as... Figure 12 As shown, heater layer 142 may further include heater layer 142e disposed between Si waveguide 141a and support substrate 510. Heater layer 142e is disposed in interlayer insulating film 522 and, for example, coupled to wiring 640 in interlayer insulating film 522. The distance between heater layer 142e and Si waveguide 141a is d1. Heater layer 142e is disposed at a position opposite to heater layer 142a across Si waveguide 141a. In this way, by disposing heater layers 142a and 142e above and below Si waveguide 141a, the power efficiency and thermal response of the phase shifter can be adjusted.

[0108] <Variations 2-5>

[0109] Figure 13 and Figure 14 An example of the cross-sectional configuration of the ranging device 1000 according to a modified example is shown. In the above embodiments and their modifications, for example, as... Figure 13 and Figure 14 As shown, a signal processing substrate 300 can be used instead of a support substrate 510. In this case, the surface of the silicon photonic layer 520 (interlayer insulating film 522) is in contact with the surface of the signal processing substrate 300, and the bonding surface between the interlayer insulating film 522 and the signal processing substrate 300 is the bonding surface S2.

[0110] In this variation, wiring 560 includes, for example, as Figure 13 As shown, via 561 is coupled to wiring 550, wiring layer 562 is coupled to via 561, and via 563 is coupled to wiring layer 562 and wiring layers in signal processing substrate 300. In this modified example, for example, as... Figure 13 As shown, wiring 530 includes wiring layer 531 coupled to heater layer 142a and vias 532 coupled to wiring layer 531 and wiring layer in signal processing substrate 300. In this variation, for example, as Figure 14 As shown, wiring 590 includes via 591 coupled to wiring 540, wiring layer 592 coupled to via 591, and via 593 coupled to wiring layer 592 and wiring layer in signal processing substrate 300.

[0111] In this way, the silicon photonics layer 520 and the signal processing substrate 300 are bonded together; therefore, compared with the first embodiment described above, the wiring coupling the silicon photonics layer 520 and the signal processing substrate 300 can be shorter. Thus, the resistance of the wiring coupling the silicon photonics layer 520 and the signal processing substrate 300 can be reduced, and the power efficiency of the ranging device 1000 can be improved.

[0112] <Variation Example 2-6>

[0113] Figure 15 An example of the cross-sectional configuration of the ranging device 1000 according to a modified example is shown. In the modified examples 2-5 described above, for example, as Figure 15 As shown, the laser chip 200 can be mounted on the signal processing substrate 300. For example, the laser chip 200 is mounted on the signal processing substrate 300 such that the active layer 210 of the laser chip 200 and the Si layer 521 or SiN layer 525 of the silicon photonics layer 520 are disposed at the same level. In this way, by mounting the laser chip 200 on the signal processing substrate 300, the laser L emitted from the laser chip 200 (active layer 210) can enter the silicon photonics layer 520.

[0114] <Variation Example 2-7>

[0115] Figure 16 An example of the cross-sectional configuration of the ranging device 1000 according to a modified example is shown. In the above embodiments and modifications 2-1, 2-2, 2-3 and 2-4, for example, as Figure 16 As shown, a wiring substrate 800 can be used instead of a support substrate 510. The wiring substrate 800 includes multiple SiO2 layers stacked on the support substrate. In the wiring substrate 800, wiring with multiple patterned wiring layers and vias connecting the wiring layers is formed in the multiple SiO2 layers.

[0116] In this variation, for example, as Figure 16 As shown, the signal processing substrate 300 is mounted on the silicon photonics layer 520. At this time, for example, as... Figure 16 As shown, wiring 650 includes wiring layer 651 coupled to signal processing substrate 300 and vias 652 coupled to wiring layer 651 and wiring layers in wiring substrate 800. Signal processing substrate 300 is electrically coupled to wiring substrate 800 through wiring 650 formed in silicon photonic layer 520. Furthermore, for example, as... Figure 16 As shown, wiring 590 includes via 591 coupled to wiring 540, wiring layer 592 coupled to via 591, and via 593 coupled to wiring layer 592 and wiring layer in wiring substrate 800.

[0117] In this way, by mounting the signal processing substrate 300 on the silicon photonics layer 520, more complex functions can be added. The signal processing substrate 300 and the wiring substrate 800 can be configured with different processing nodes. Furthermore, multiple signal processing substrates 300 can be mounted on the silicon photonics layer 520.

[0118] <3. Application Examples>

[0119] The technology according to this disclosure is applicable to a variety of products. For example, the technology according to this disclosure can be implemented as a device installed on any kind of mobile body such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility devices, aircraft, drones, ships, robots, construction machinery, or agricultural machinery (tractors).

[0120] Figure 17 This is a block diagram illustrating an example of a schematic configuration of a vehicle control system 7000, which is an example of a mobile body control system applicable as an embodiment of the technology according to this disclosure. The vehicle control system 7000 includes a plurality of electronic control units interconnected via a communication network 7010. Figure 17 In the illustrated example, 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 connecting the multiple control units can be an in-vehicle communication network conforming to any standard, such as Controller Area Network (CAN), Local Area Network (LIN), Local Area Network (LAN), FlexRay, etc. Each control unit includes: a microcomputer for performing calculations according to various programs; a storage unit for storing programs executed by the microcomputer, parameters for various operations, etc.; and a drive circuit for driving various control target devices. Each control unit further includes: a network interface (I / F) for communicating with other control units via the communication network 7010; and a communication I / F for communicating with devices, sensors, etc., inside and outside the vehicle via wired or wireless communication. Figure 17 The integrated control unit 7600 shown is configured with a microcomputer 7610, a general communication I / F 7620, a dedicated communication I / F 7630, a positioning unit 7640, a beacon receiver 7650, an in-vehicle equipment I / F 7660, a voice / image output unit 7670, an in-vehicle network I / F 7680, and a storage unit 7690. Other control units similarly include microcomputers, communication I / Fs, and storage units.

[0121] The drive system control unit 7100 controls the operation of equipment related to the vehicle's drive system according to various programs. For example, the drive system control unit 7100 acts as a control device to control: drive force generating equipment for generating the vehicle's driving force, such as an internal combustion engine or drive motor; drive force transmission mechanisms for transmitting the driving force to the wheels; steering mechanisms for adjusting the vehicle's steering angle; and braking devices for generating the vehicle's braking force. The drive system control unit 7100 may also have the functions of control devices for anti-lock braking systems (ABS), electronic stability control (ESC), etc.

[0122] The drive system control unit 7100 is connected to a vehicle status detection unit 7110. The vehicle status detection unit 7110 includes, for example, at least one of the following: a gyroscope sensor for detecting the angular velocity of the vehicle's axial rotational motion, an acceleration sensor for detecting the vehicle's acceleration, and sensors for detecting the amount of operation of the accelerator pedal, the amount of operation of the brake pedal, the steering angle of the steering wheel, engine speed, or wheel rotation speed. The drive system control unit 7100 performs arithmetic processing using signals input from the vehicle status detection unit 7110 to control the internal combustion engine, drive motor, electric power steering system, braking system, etc.

[0123] The body system control unit 7200 controls the operation of various devices installed on the vehicle body according to various programs. For example, the body system control unit 7200 acts as a control device to control: keyless entry system, smart key system, power windows, or various lights such as headlights, reversing lights, brake lights, turn signals, and fog lights. In this case, the body system control unit 7200 can receive radio waves or signals from various switches transmitted from a mobile device that replaces the key as input. The body system control unit 7200 receives these input radio waves or signals to control the vehicle's door locking devices, power windows, lights, etc.

[0124] The battery control unit 7300 controls the secondary battery 7310, which serves as the power source for the drive motor, according to various programs. For example, the battery control unit 7300 receives information from the battery device, including the secondary battery 7310, regarding battery temperature, battery output voltage, and remaining battery charge. The battery control unit 7300 uses these signals to perform arithmetic processing, such as temperature regulation control of the secondary battery 7310 or control of the cooling equipment of the battery device.

[0125] The external information detection unit 7400 detects information about the exterior of the vehicle, including the vehicle control system 7000. For example, the external information detection unit 7400 is connected to at least one of the imaging unit 7410 and the external 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 external information detection unit 7420 may include at least one of the following: an environmental sensor for detecting current atmospheric or weather conditions, and a surrounding information detection sensor for detecting other vehicles, obstacles, pedestrians, etc., around the vehicle, including the vehicle control system 7000.

[0126] Environmental sensors may be, for example, at least one of the following: a raindrop sensor for detecting rain, a fog sensor for detecting fog, a sunlight sensor for detecting sunlight intensity, and a snow sensor for detecting snowfall. Surrounding information detection sensors may be at least one of the following: an ultrasonic sensor, a radar device, and a LIDAR device (light detection and ranging device, or laser imaging detection and ranging device). Each of the imaging unit 7410 and the exterior information detection unit 7420 may be configured as an independent sensor or device, or may be configured as a device in which multiple sensors or devices are integrated.

[0127] Figure 18 Examples of the mounting positions of the imaging unit 7410 and the exterior information detection unit 7420 are shown. Imaging units 7910, 7912, 7914, 7916, and 7918 can be arranged at 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 primarily acquire images of the front of the vehicle 7900. The imaging units 7912 and 7914 arranged at the side mirrors primarily acquire images of the sides of the vehicle 7900. The imaging unit 7916 arranged at the rear bumper or rear door primarily acquires images 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 vehicles, pedestrians, obstacles, signals, traffic signs, lanes, etc., ahead.

[0128] Incidentally, Figure 18 Examples of the imaging ranges of the various imaging units 7910, 7912, 7914, and 7916 are shown. Imaging range a represents the imaging range of the imaging unit 7910 located on the front nose. Imaging ranges b and c represent the imaging ranges of the imaging units 7912 and 7914 located on the side mirrors, respectively. Imaging range d represents the imaging range of the imaging unit 7916 located on the rear bumper or rear door. For example, by superimposing the image data captured by the imaging units 7910, 7912, 7914, and 7916, a bird's-eye view of the vehicle 7900 viewed from above can be obtained.

[0129] The exterior information detection units 7920, 7922, 7924, 7926, 7928, and 7930, located at the front, rear, sides, and corners of the vehicle 7900, as well as on the upper part of the windshield inside the vehicle, can be ultrasonic sensors or radar devices. The exterior information detection units 7920, 7926, and 7930, located at the front nose, rear bumper, rear door, and on the upper part of the windshield inside the vehicle 7900, can be LIDAR devices. These exterior information detection units 7920–7930 are primarily used to detect vehicles, pedestrians, obstacles, etc., ahead.

[0130] Back Figure 17 The description continues. The exterior information detection unit 7400 causes the imaging unit 7410 to image an image of the exterior of the vehicle and receives the image data. Furthermore, the exterior information detection unit 7400 receives detection information from the exterior information detection section 7420 connected to it. When the exterior information detection section 7420 is an ultrasonic sensor, radar device, or LIDAR device, the exterior information detection unit 7400 transmits ultrasonic waves, electromagnetic waves, etc., and receives information about the received reflected waves. Based on the received information, the exterior information detection unit 7400 can perform processing for detecting objects (such as people, vehicles, obstacles, signs, symbols, etc. on the road surface) or processing for the distance to the detected objects. The exterior information detection unit 7400 can perform environmental recognition processing based on the received information to identify rain, fog, road conditions, etc. The exterior information detection unit 7400 can calculate the distance to objects outside the vehicle based on the received information. Furthermore, based on the received image data, the exterior information detection unit 7400 can perform image recognition processing for identifying objects (such as people, vehicles, obstacles, signs, symbols, etc. on the road surface), or perform distance processing for detected objects. The exterior information detection unit 7400 can perform processing on the received image data, such as distortion correction and alignment, and generate bird's-eye view or panoramic image by combining image data from multiple different imaging units 7410. The exterior information detection unit 7400 can use image data from different imaging units 7410 to perform viewpoint switching processing.

[0131] The in-vehicle information detection unit 7500 detects information inside the vehicle. The in-vehicle information detection unit 7500 can be connected to a driver state detection unit 7510, which detects the driver's state. The driver state detection unit 7510 may include a camera that captures images of the driver, a biosensor that detects the driver's biological information, and a microphone that collects sounds inside the vehicle. The biosensor can be placed on the seat surface, steering wheel, etc., and detects the biological information of passengers sitting in the seat or the 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 can calculate the driver's fatigue level or the driver's level of concentration, or it can determine whether the driver is dozing off. The in-vehicle information detection unit 7500 can perform processing such as noise cancellation on the audio signals obtained through sound collection.

[0132] 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 capable of input operation by a passenger, such as a touch panel, button, microphone, switch, lever, etc. The integrated control unit 7600 can receive data obtained through voice recognition of voice input via the microphone. The input unit 7800 can be a remote control device using infrared or other radio waves, or it can be an external connection device such as a mobile phone or personal digital assistant (PDA) 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. Furthermore, the input unit 7800 may include an input control circuit, etc., which generates an input signal based on the information input by the passenger or others using the aforementioned input unit 7800, and outputs the generated input signal to the integrated control unit 7600. Passengers can input various data into the vehicle control system 7000 through the operation input unit 7800 and process operation instructions.

[0133] The storage unit 7690 may include a read-only memory (ROM) for storing various programs executed by a microcomputer and a random access memory (RAM) for storing various parameters, operation results, sensor values, etc. Furthermore, 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.

[0134] The Universal Communication I / F 7620 is a widely used communication I / F that mediates communication with various devices present in the external environment 7750. The Universal Communication I / F 7620 can implement cellular communication protocols such as GSM, WiMAX, LTE, and LTE-A, or other wireless communication protocols such as Wi-Fi (also known as Wi-Fi) and Bluetooth. The Universal Communication I / F 7620 can connect to devices (e.g., application servers or control servers) on external networks (e.g., the Internet, cloud networks, or company-specific networks) via base stations or access points. Furthermore, the Universal Communication I / F 7620 can use peer-to-peer (P2P) technology to connect to terminals located near the vehicle (e.g., terminals belonging to drivers, pedestrians, or shopkeepers, or machine-type communication (MTC) terminals).

[0135] The Dedicated Communication I / F 7630 is a communication I / F that supports communication protocols developed for vehicle use. The Dedicated Communication I / F 7630 can implement standard protocols, such as Wireless Access in a Vehicle Environment (WAVE) (a combination of IEEE 802.11p as the lower layer and IEEE 1609 as the upper layer), Dedicated Short Range Communication (DSRC), or cellular communication protocols. The Dedicated Communication I / F 7630 typically performs V2X communication including one or more of the following concepts: vehicle-to-vehicle (V2V) communication, road-to-vehicle (V2V) communication, vehicle-to-home (V2N) communication, and pedestrian-to-vehicle (V2P) communication.

[0136] The positioning unit 7640 can perform positioning by receiving Global Navigation Satellite System (GNSS) signals from GNSS satellites (e.g., GPS signals from Global Positioning System (GPS) satellites) and generating location information including the vehicle's latitude, longitude, and altitude. Incidentally, the positioning unit 7640 can identify its current location by exchanging signals with a wireless access point, or by obtaining location information from a terminal such as a mobile phone, a Personal Handheld System (PHS), or a smartphone with positioning capabilities.

[0137] The beacon receiver 7650 can receive radio waves or electromagnetic waves transmitted from radio stations installed on roads, etc., thereby obtaining information such as current location, congestion, road closure, and estimated time. Incidentally, the functionality of the beacon receiver 7650 can be included in the aforementioned dedicated communication I / F 7630.

[0138] 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 within the vehicle. The in-vehicle device I / F 7660 can establish a wireless connection using wireless communication protocols such as Wireless LAN, Bluetooth, Near Field Communication (NFC), or Wireless Universal Serial Bus (WUSB). Furthermore, the in-vehicle device I / F 7660 can establish a wired connection via a connection terminal (and cable, if necessary) not shown in the figure, through Universal Serial Bus (USB), High Definition Multimedia Interface (HDMI), Mobile High Definition Link (MHL), etc. The in-vehicle devices 7760 may include at least one of the following: passenger-owned mobile devices and wearable devices, and information devices loaded into or attached to the vehicle. The in-vehicle device 7760 may also include a navigation device that searches for a path to any destination. The in-vehicle device I / F 7660 exchanges control signals or data signals with these in-vehicle devices 7760.

[0139] The vehicle network I / F 7680 is an interface that mediates communication between the microcomputer 7610 and the communication network 7010. The vehicle network I / F 7680 transmits and receives signals according to a predetermined protocol supported by the communication network 7010.

[0140] 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 following: general communication I / F 7620, dedicated communication I / F 7630, positioning unit 7640, beacon receiving unit 7650, in-vehicle equipment I / F 7660, and in-vehicle network I / F 7680. For example, the microcomputer 7610 can calculate control target values ​​for the drive force generation device, steering mechanism, or braking device based on the obtained relevant information about the inside or outside of the vehicle, and output control commands to the drive system control unit 7100. For example, the microcomputer 7610 can perform cooperative control aimed at realizing the functions of an advanced driver assistance system (ADAS), including collision avoidance or impact buffering for the vehicle, distance-based following driving, speed-maintaining driving, vehicle collision warning, lane departure warning, etc. Furthermore, the microcomputer 7610 can control the drive force generation device, steering mechanism, and braking device based on the information obtained about the vehicle's surrounding environment, thereby performing coordinated control intended for automatic driving and other purposes that do not depend on the driver's operation.

[0141] The microcomputer 7610 can 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 following: 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, and an in-vehicle network I / F 7680. It also generates local map information including information about the vehicle's current surrounding environment. Furthermore, the microcomputer 7610 can predict hazards such as vehicle collisions, pedestrian approach, and entry into closed roads based on the obtained information, and generate alarm signals. These alarm signals can be used to generate warning sounds or illuminate warning lights.

[0142] The sound / image output unit 7670 transmits at least one of sound and image output signals to an output device capable of visually or audibly notifying passengers of the vehicle or the outside of the vehicle. Figure 17 In this example, an audio speaker 7710, a display unit 7720, and an instrument panel 7730 are shown as output devices. The display unit 7720 may include at least one of an in-vehicle display and a head-up display. The display unit 7720 may have augmented reality (AR) display functionality. Output devices may be other than these devices, such as headphones, wearable devices like glasses displays worn by passengers, projectors, lamps, etc. When the output device is a display device, it visually displays the results obtained from 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.). Furthermore, when the output device is an audio output device, it converts an audio signal composed of played audio data or sound data into an analog signal and outputs the analog signal audibly.

[0143] Incidentally, in Figure 17 In the illustrated example, at least two control units connected to each other via communication network 7010 can be integrated into one control unit. Alternatively, each individual control unit may include multiple control units. Furthermore, the vehicle control system 7000 may include other control units not shown in the figures. Additionally, some or all of the functions performed by one control unit in the above-described control units can be assigned to another control unit. That is, predetermined computational processing can be performed by any one control unit, as long as information is transmitted and received via communication network 7010. Similarly, sensors or devices connected to one control unit can be connected to another control unit, and multiple control units can transmit and receive detection information from each other via communication network 7010. It should be noted that computer programs can be installed on any control unit, etc., for implementing the use... Figures 1 to 16Each function of the ranging device 1000 described herein is also described. Furthermore, a computer-readable recording medium in which such a computer program is stored may be provided. The recording medium may be, for example, a magnetic disk, optical disk, magneto-optical disk, flash memory, etc. Alternatively, the aforementioned computer program can be distributed via a network, for example, without using a recording medium.

[0144] In the aforementioned vehicle control system 7000, for example, it can be used Figures 1 to 16 The ranging device 1000 described above is used as a component of a LIDAR for use as an environmental sensor, a component of an OCT (Optical Coherence Tomography) device, a spectral module using infrared light and silicon photonics, or a component of an important sensor.

[0145] In addition, using Figures 1 to 16 At least some components of the ranging device 1000 described above can be Figure 17 This is implemented in a module (e.g., an integrated circuit module including a single chip) of the integrated control unit 7600 shown. Alternatively, it can be implemented using... Figures 1 to 16 The distance measuring device 1000 described above can be used... Figure 17 This is achieved through multiple control units of the vehicle control system 7000 shown in the figure.

[0146] In addition, using Figures 1 to 16 At least some components of the ranging device 1000 described above can be Figure 17 This is implemented in a module (e.g., an integrated circuit module including a single chip) of the integrated control unit 7600 shown. Alternatively, it can be implemented using... Figures 1 to 16 The distance measuring device 1000 described above can be used... Figure 17 This is achieved through multiple control units of the vehicle control system 7000 shown in the figure.

[0147] As described above, this disclosure has been described through embodiments and variations thereof; however, this disclosure is not limited to the above embodiments, and various modifications can be made. It should be noted that the effects described in this specification are merely illustrative. The effects of this disclosure are not limited to those described in this specification. This disclosure may have effects other than those described in this specification.

[0148] In addition, for example, this disclosure may have the following configuration. (1)

[0150] A semiconductor device includes a stack comprising a silicon photonic layer and a support substrate bonded together, wherein...

[0151] The silicon photonic layer includes:

[0152] Waveguides, through which optical signals are transmitted, and

[0153] A first metal film is configured to face the supporting substrate, and a waveguide is disposed between the first metal film and the supporting substrate.

[0154] The first metal film includes a first heater layer that serves as a heater for the waveguide. (2)

[0156] According to the semiconductor device of (1), wherein

[0157] A waveguide consists of a first waveguide and a second waveguide, which are made of different materials than each other.

[0158] The first heater layer includes:

[0159] A second heater layer is arranged opposite to the support substrate, and a first waveguide is located between the second heater layer and the support substrate.

[0160] The third heater layer is positioned opposite the support substrate, and the second waveguide is located between the third heater layer and the support substrate.

[0161] In the silicon photonics layer, the second heater layer and the third heater layer are disposed in different layers from each other, and

[0162] The distance between the second heater layer and the first waveguide is different from the distance between the third heater layer and the second waveguide. (3)

[0164] According to the semiconductor device in (2), wherein

[0165] The silicon photonic layer includes a second metal film disposed between the waveguide and the supporting substrate, and

[0166] The second metal film includes a fourth heater layer that serves as a heater for the waveguide. (4)

[0168] According to the semiconductor device of (3), the fourth heater layer is arranged in a position not opposite to the first heater layer. (5)

[0170] According to the semiconductor device of (3), the fourth heater layer is arranged at a position opposite to the first heater layer. (6)

[0172] According to the semiconductor device of (3), the silicon photonic layer includes a heat dissipation control section at a position opposite to the fourth heater layer, and a waveguide is therebetween. (7)

[0174] According to the semiconductor device of (6), the heat dissipation control unit includes a recess formed on the surface of the silicon photonic layer. (8)

[0176] According to the semiconductor device of (7), the recess has a surface on the side opposite to the fourth heater layer in the surface of the waveguide and a bottom surface of the two side surfaces. (9)

[0178] According to the semiconductor device of (6), the heat dissipation control unit includes a second metal film independent of the circuit wiring. (10)

[0180] According to the semiconductor device of (9), the second metal film includes a heat dissipation layer, the heat dissipation layer including a surface on which recesses and protrusions are formed. (11)

[0182] A semiconductor device according to any one of (1) to (10), wherein

[0183] The silicon photonic layer includes a detector configured to detect signals guided through a waveguide, and

[0184] The support substrate includes a signal processing substrate configured to process signals detected by a detector and control a first heater layer. (12)

[0186] The semiconductor device according to (11) further includes a light source chip configured to allow an optical signal to enter the waveguide, wherein

[0187] The light source chip is mounted on the signal processing substrate. (13)

[0189] A semiconductor device according to any one of (1) to (10), wherein

[0190] The silicon photonic layer includes detectors configured to detect signals guided through the waveguide.

[0191] The support substrate includes a wiring substrate configured to transmit signals detected by a detector and signals controlling the first heater layer.

[0192] The semiconductor device includes a signal processing substrate mounted on a silicon photonics layer and electrically coupled to a wiring substrate via the silicon photonics layer. (14)

[0194] A ranging device, comprising:

[0195] The light source chip outputs light signals;

[0196] The silicon photonics layer includes: a waveguide through which an optical signal output from a light source chip is transmitted; and a detector configured to detect the signal guided through the waveguide.

[0197] Support substrate, bonded to silicon photonic layer; and

[0198] The signal processing board processes the signal detected by the detector, wherein...

[0199] The silicon photonic layer further includes a first metal film, which is positioned opposite to the supporting substrate, and a waveguide is interposed between the first metal film and the supporting substrate.

[0200] The first metal film includes a first heater layer that serves as a heater for the waveguide.

[0201] This application claims the benefit of Japanese priority patent application JP2023-058936, filed with the Japan Patent Office on March 31, 2023, the entire contents of which are incorporated herein by reference.

[0202] Those skilled in the art will understand that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors, as long as they are within the scope of the appended claims or their equivalents.

Claims

1. A semiconductor device comprising a stack including a silicon photonics layer and a support substrate attached to each other, wherein the silicon photonics layer includes: a waveguide through which an optical signal is transmitted, and a first metal film disposed opposite the support substrate with the waveguide interposed, and the first metal film includes a first heater layer configured to function as a heater for the waveguide.

2. The semiconductor device according to claim 1, wherein the waveguide includes a first waveguide and a second waveguide that are different in material, the first heater layer includes: a second heater layer disposed opposite the support substrate with the first waveguide interposed, and a third heater layer disposed opposite the support substrate with the second waveguide interposed, in the silicon photonics layer, the second heater layer and the third heater layer are disposed in different layers from each other, and a distance between the second heater layer and the first waveguide and a distance between the third heater layer and the second waveguide are different from each other.

3. The semiconductor device according to claim 2, wherein the silicon photonics layer includes a second metal film disposed between the waveguide and the support substrate, and the second metal film includes a fourth heater layer configured to function as a heater for the waveguide.

4. The semiconductor device according to claim 3, wherein the fourth heater layer is arranged at a position non-opposite to the first heater layer.

5. The semiconductor device according to claim 3, wherein the fourth heater layer is arranged at a position opposite to the first heater layer.

6. The semiconductor device according to claim 3, wherein the silicon photonics layer includes a heat dissipation control portion at a position opposite to the fourth heater layer, the waveguide being interposed between the heat dissipation control portion and the fourth heater layer.

7. The semiconductor device according to claim 6, wherein the heat dissipation control portion includes a recess formed on a surface of the silicon photonics layer.

8. The semiconductor device according to claim 7, wherein the recess has a bottom surface disposed to surround a surface of the waveguide on a side opposite to the fourth heater layer and two side surfaces.

9. The semiconductor device according to claim 6, wherein the heat dissipation control portion includes a second metal film independent of a circuit wiring.

10. The semiconductor device according to claim 9, wherein the second metal film includes a heat dissipation layer including a surface on which a recess and a protrusion are formed.

11. The semiconductor device according to claim 1, wherein the silicon photonics layer includes a detector configured to detect a signal guided through the waveguide, and the support substrate includes a signal processing substrate configured to process the signal detected by the detector and control the first heater layer.

12. The semiconductor device of claim 11, further comprising: a light source chip configured to cause the optical signal to enter the waveguide, wherein the light source chip is mounted on the signal processing substrate.

13. The semiconductor device according to claim 1, wherein the silicon photonics layer includes a detector configured to detect a signal guided through the waveguide, the support substrate includes a wiring substrate configured to transmit the signal detected by the detector and a signal for controlling the first heater layer, and the semiconductor device includes a signal processing substrate mounted on the silicon photonics layer and electrically coupled to the wiring substrate through the silicon photonics layer.

14. A range finder device comprising: a light source chip outputting an optical signal; A silicon photonics layer including: a waveguide through which the optical signal output from the light source chip is transmitted; and a detector configured to detect a signal guided through the waveguide; a support substrate attached to the silicon photonics layer; and a signal processing substrate that processes a signal detected by the detector, wherein the silicon photonics layer further includes a first metal film disposed opposite the support substrate with the waveguide therebetween, and the first metal film includes a first heater layer configured to function as a heater for the waveguide.

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