Distance measuring device

Abstract

A distance measuring device according to one aspect of the present disclosure includes a first substrate. The first substrate has a first optical waveguide capable of transmitting a chirp signal, a splitter capable of splitting the chirp signal into a transmission signal and a reference signal, and a coupler detector block capable of outputting a beat signal based on the reference signal and a return signal. The distance measuring device includes a second substrate stacked on the first substrate. The second substrate has a converter capable of outputting a digital beat signal based on the beat signal, and a controller capable of outputting an electronic control signal for controlling generation of the chirp signal.

Description

Identification of Related Applications

[0001] This application claims priority to Japanese Patent Application No. 2021-168293, filed on November 9, 2021, the contents of which are incorporated herein by reference. [Technical field]

[0002] The present disclosure relates to a distance measuring device. [Background technology]

[0003] In recent years, LiDAR (Light Detection and Ranging) systems have been developed that use photonic integration circuits (PICs) in which optical components such as Si waveguides are stacked on an SOI substrate instead of optical fibers (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent Application Publication No. 2021 / 0109195 Summary of the Invention [Problem to be solved by the invention]

[0005] In such systems, further miniaturization is required, and therefore it is desirable to provide a range finder that can be miniaturized. [Means for solving the problem]

[0006] A distance measuring device according to one aspect of the present disclosure includes a first substrate. The first substrate includes a first optical waveguide capable of transmitting a chirp signal, a splitter capable of splitting the chirp signal into a transmission signal and a reference signal, and a coupler detector block capable of outputting a beat signal based on the reference signal and a return signal. The distance measuring device includes a second substrate laminated on the first substrate. The second substrate includes a converter capable of outputting a digital beat signal based on the beat signal, and a controller capable of outputting an electronic control signal for controlling generation of the chirp signal. A distance measuring device according to another aspect of the present disclosure includes a first substrate and a second substrate bonded to the first substrate. The first substrate includes one or more optical circuits for outputting a transmission signal to a target and receiving a return signal from the target. The second substrate includes one or more electronic circuits for controlling generation of the transmission signal and processing the return signal. A system according to one aspect of the present disclosure includes a target and a distance measuring device for measuring a distance to the target. The distance measuring device includes a first substrate. The first substrate has a first optical waveguide capable of transmitting a chirp signal, a splitter capable of splitting the chirp signal into a transmission signal and a reference signal, and a coupler detector block capable of outputting a beat signal based on the reference signal and a return signal. The distance measuring device has a second substrate laminated on the first substrate. The second substrate has a converter capable of outputting a digital beat signal based on the beat signal, and a controller capable of outputting an electronic control signal for controlling generation of the chirp signal. The distance measuring device according to one aspect of the present disclosure includes a PIC substrate and a signal processing substrate. In the PIC substrate, the first waveguide, the splitter, the second waveguide, and the signal generating unit are formed in a common Si layer. The first waveguide transmits the chirp signal. The splitter splits the chirp signal into a transmission signal and a reference signal. The second waveguide transmits a return signal equivalent to a signal whose phase is delayed relative to the transmission signal. The signal generating unit generates a beat signal based on the reference signal and the return signal. The signal processing board is formed with a converter that performs AD conversion of the beat signal and a signal processing section that processes the digital beat signal generated by the converter. The PIC board and the signal processing board are stacked on top of each other and are electrically connected to each other via the joint surfaces of the PIC board and the signal processing board.

[0007] In a distance measuring device according to one aspect of the present disclosure, a first waveguide, a splitter, a second waveguide, and a signal generating unit are formed in a common Si layer in a PIC substrate. A converter and a signal processing unit are formed in a signal processing substrate. The PIC substrate and the signal processing substrate are stacked on top of each other and are electrically connected to each other via the joint surfaces of the PIC substrate and the signal processing substrate. This allows for a smaller size than a module in which multiple RF components are coupled via optical fibers. [Brief description of the drawings]

[0008] The accompanying drawings are included to provide a further understanding of the technology, and are incorporated in and constitute a part of this specification. The drawings illustrate one embodiment and, together with the description, serve to explain the principles of the technology. [Figure 1] 1 is a diagram illustrating a schematic configuration example of a distance measuring device according to a first embodiment of the present disclosure. [Diagram 2] 2 is a diagram illustrating an example of a cross-sectional configuration of the distance measuring device in FIG. 1. [Diagram 3] FIG. 2 is a diagram illustrating an example of a schematic configuration of the antenna of FIG. [Figure 4] 4 is a diagram illustrating an example of a cross-sectional configuration of the Si antenna taken along line AA in FIG. 3. [Diagram 5] 4 is a diagram illustrating an example of a cross-sectional configuration of the Si antenna taken along line BB in FIG. 3. [Figure 6] FIG. 2 is a diagram illustrating an example of a schematic configuration of a detector in FIG. [Figure 7] FIG. 7 is a diagram illustrating an example of a perspective configuration of the detector in FIG. 6. [Figure 8A] 2A to 2C are cross-sectional views for explaining a method of manufacturing the distance measuring device in FIG. [Figure 8B] FIG. 8B is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 8A. [Figure 8C] FIG. 8C is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 8B. [Figure 8D]FIG. 8C is a cross-sectional view for explaining the subsequent manufacturing method. [Figure 8E] FIG. 8E is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 8D. [Figure 8F] FIG. 8F is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 8E. [Figure 8G] FIG. 8C is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 8F. [Figure 9] FIG. 13 is a diagram illustrating an example of a schematic configuration of a distance measuring device according to a second embodiment of the present disclosure. [Figure 10] 10 is a diagram illustrating an example of a cross-sectional configuration of the distance measuring device in FIG. 9. [Figure 11] 10 is a diagram illustrating an example of a planar configuration of a GePD in the distance measuring device of FIG. 9. [Figure 12A] 10A to 10C are cross-sectional views for explaining a method of manufacturing the distance measuring device in FIG. [Figure 12B] 12B is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 12A. [Figure 12C] FIG. 12C is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 12B. [Figure 12D] FIG. 12C is a cross-sectional view for explaining the subsequent manufacturing method. [Figure 12E] FIG. 12E is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 12D. [Figure 12F] FIG. 12C is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 12E. [Figure 12G] FIG. 12C is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 12F. [Figure 13] FIG. 13 is a diagram illustrating an example of a schematic configuration of a distance measuring device according to a third embodiment of the present disclosure. [Figure 14] 14 is a diagram illustrating an example of a cross-sectional configuration of the distance measuring device of FIG. 13. [Figure 15] 14 is a diagram illustrating a modified example of the cross-sectional configuration of the distance measuring device in FIG. 13. [Figure 16] 14 is a diagram illustrating a modified example of the cross-sectional configuration of the distance measuring device in FIG. 13. [Figure 17] 14 is a diagram illustrating a modified example of the cross-sectional configuration of the distance measuring device in FIG. 13. [Figure 18] FIG. 13 is a diagram illustrating an example of a schematic configuration of a distance measuring device according to a fourth embodiment of the present disclosure. [Figure 19] 19 is a diagram illustrating an example of a cross-sectional configuration of the distance measuring device in FIG. 18. [Figure 20A] 19A to 19C are cross-sectional views for explaining a method of manufacturing the distance measuring device of FIG. 18. [Figure 20B] FIG. 20B is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 20A. [Figure 20C] FIG. 20C is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 20B. [Figure 20D] FIG. 20C is a cross-sectional view illustrating a subsequent manufacturing method. [Figure 20E] FIG. 20E is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 20D. [Figure 20F] FIG. 20F is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 20E. [Figure 21] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Figure 22] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Diagram 23] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Figure 24] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Diagram 25] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Figure 26] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Figure 27] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Figure 28] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Figure 29]11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Figure 30A] 30 is a cross-sectional view for explaining a method of manufacturing the distance measuring device of FIG. 29. [Figure 30B] FIG. 30B is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 30A. [Figure 30C] FIG. 30C is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 30B. [Figure 30D] FIG. 30D is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 30C. [Diagram 31] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Diagram 32] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Figure 33A] 33A to 33C are cross-sectional views for explaining a method of manufacturing the distance measuring device of FIG. 32. [Figure 33B] FIG. 33B is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 33A. [Figure 33C] FIG. 33C is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 33B. [Figure 33D] FIG. 33D is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 33C. [Figure 33E] FIG. 33E is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 33D. [Figure 33F] FIG. 33F is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 33E. [Figure 33G] FIG. 33F is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 33F. [Fig. 33H] FIG. 33C is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 33G. [Figure 33I] FIG. 33C is a cross-sectional view illustrating the manufacturing method subsequent to FIG. 33H. [Diagram 34] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Diagram 35]11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Diagram 36] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Figure 37] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Figure 38] 11A and 11B are diagrams illustrating a modification of the cross-sectional configuration of the distance measuring device according to each embodiment and the modification thereof. [Figure 39] 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; [Diagram 40] 4 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order. 1. First embodiment (FIGS. 1 to 8G) An example of stacking a PIC board and a signal processing board with Cu-Cu connection 2. Second embodiment (FIGS. 9 to 12G) An example of stacking a PIC board and a signal processing board with TCV connection 3. Third embodiment (FIGS. 13 and 14) An example of stacking a PIC board and a signal processing board with chip-on-wafer (CoW) connection 4. Modification of the third embodiment (FIGS. 15 to 17) Alignment variations 5. Fourth embodiment (FIGS. 18 to 20F) An example of a PIC layer attached onto a signal processing board 6. Modification of the Fourth Embodiment (FIG. 21) Example of STI placed directly under the Si antenna 7. Modifications of each embodiment Modification A: Example in which a tapered portion is provided at the input end of the optical waveguide (FIGS. 22 to 24) Modification B: Example of using a surface-emitting type laser (FIGS. 25 to 28) Modification C: Example in which a gap is provided directly above and below the Si antenna (FIGS. 29 to 31) Modification D: Example in which a gap is provided directly under the Si antenna (Figs. 32 to 34) Modification E: An example in which a reflective layer is provided directly under the Si antenna (Figure 35) Modification F: Example in which the laser and the signal processing board are connected with bonding wires (FIGS. 36 to 38) 8. Application examples (Fig. 39, Fig. 40)

[0010] <1. First embodiment> composition Fig. 1 shows a schematic configuration example of a distance measuring device 100 according to a first embodiment of the present disclosure. Fig. 2 shows a cross-sectional configuration example of the distance measuring device 100. The distance measuring device 100 is a LiDAR using an FMCW (Frequency Modulated Continuous Wave) method. In the FMCW LiDAR, a laser light (transmission signal) modulated so that the frequency increases linearly with time is continuously emitted, and the distance is calculated from the frequency difference between the transmission signal and the reflected light (return signal).

[0011] The distance measuring device 100 includes an upper die 200 and a lower die 300, for example, as shown in Fig. 1. The upper die 200 and the lower die 300 are stacked on each other, for example, as shown in Fig. 2, and are electrically connected to each other via a bonding surface S1 between the upper die 200 and the lower die 300. Throughout this specification, the terms gdie,h gehip,h and / or similar terms may be used interchangeably and / or may be referred to as a substrate.

[0012] (Upper die 200) The upper die 200 includes, for example, a laser 210, a modulator 220, a splitter 230, a circulator 240, an antenna 250, a coupler 260, and a detector 270, as shown in Fig. 1. In the upper die 200, the modulator 220, the splitter 230, the circulator 240, the antenna 250, the coupler 260, and the detector 270 are formed in a PIC (Photonic Integration Circuit) board 200A. The combination of the coupler 260 and the detector 270 may be called, for example, a coupler-detector block that outputs a beat signal.

[0013] The laser 210 is a light source chip that generates an optical signal. The laser 210 is, for example, a chip-shaped edge-emitting semiconductor laser, and emits laser light L of a predetermined fixed wavelength (for example, 1550 nm) from an end face of the active layer 211 according to the control of the controller 310. The laser 210 is mounted on the PIC substrate 200A so that the laser light L is incident on an end face (optical waveguide WG1 described later) of the PIC substrate 200A. The laser 210 is mounted on the PIC substrate 200A so that the optical spot of the laser 210 (optical spot generated on the end face of the active layer 211) is at the same height as the Si layer 201 (optical waveguide WG1). A cutout portion 206 is formed in the PIC substrate 200A, and the laser 210 is mounted on a connection pad 207 provided on the bottom face of the cutout portion 206. The electrodes of the laser 210 and the connection pads 207 are made of, for example, Cu (copper), and are joined to each other via bumps 212 made of Cu.

[0014] 2, the PIC substrate 200A has a Si layer 201, an interlayer insulating film 202 sandwiching the Si layer 201, and a BOX (Buried Oxide) layer 203. The BOX layer 203 and the Si layer 201 are obtained by removing a Si substrate 111, which will be described later, from a SOI (Silicon on Insulator) substrate 110, which will be described later. The BOX layer 203 is made of SiO 2 The interlayer insulating film 202 is a layer formed on the SOI substrate 110, and is made up of a plurality of stacked SiO2 A plurality of patterned wiring layers and vias connecting the wiring layers are formed in the layer. The surface of the interlayer insulating film 202 is the bottom surface of the upper die 200. The surface of the interlayer insulating film 202 is in contact with the upper surface of the lower die 300 (interlayer insulating film 302 described later). A connection pad 204 made of Cu is exposed on the surface of the interlayer insulating film 202. Meanwhile, a connection pad 303 made of Cu is exposed on the upper surface of the lower die 300 (interlayer insulating film 302 described later). The connection pad 204 and the connection pad 303 are bonded to each other. As a result, the PIC substrate 200A and the lower die 300 are bonded to each other at the bottom surface of the upper die 200 and the top surface of the lower die 300. In FIG. 2, the bonding surface between the bottom surface of the upper die 200 and the top surface of the lower die 300 (interlayer insulating film 302 described later) is expressed as S1. The surface of the BOX layer 203 is the top surface of the upper die 200, which is the input / output surface S2. As can be seen, the Cu-Cu bonding between the dies 200, 300 using the connection pads 204, 303 does not require a wiring layer between the antenna 251 and the input / output surface S2, but the presence of such a wiring layer can cause losses of light transmitted and received by the antenna 251. Thus, the Cu-Cu bonding between the dies 200, 300 in FIG. 2 allows for improved light transmission and reception.

[0015] Optical waveguides WG1, WG2, and WG3 are provided on the Si layer 201. The optical waveguide WG1 extends from an end face of the PIC substrate 200A to the antenna 250 via the modulator 220, the splitter 230, and the circulator 240. The optical waveguide WG2 is an optical waveguide branched off from the optical waveguide WG1 at the splitter 230, and is coupled to one input end (optical waveguide 261 described below) of the coupler 260. The optical waveguide WG3 is an optical waveguide branched off from the optical waveguide WG1 at the circulator 240, and is coupled to the other input end (optical waveguide 262 described below) of the coupler 260.

[0016] A laser light L emitted from a laser 210 is incident on the optical waveguide WG1. The laser light L propagating through the optical waveguide WG1 is input to the modulator 220. The modulator 220 frequency-modulates the laser light L according to the control of the controller 310. The modulator 220 modulates the laser light L, for example, so that the frequency increases linearly with time, and then modulates the laser light L so that the frequency decreases linearly with time. The modulator 220 periodically repeats, for example, such a linear increase and decrease in frequency, and outputs a transmission signal Stx generated thereby to the splitter 230 via the optical waveguide WG1. The transmission signal Stx is a chirp signal obtained by frequency-modulating the laser light L by the modulator 220. The modulator 220 is formed, for example, on the Si layer 201. The modulator 220 is formed, for example, of a Mach-Zehnder interferometer in which a Si waveguide is branched into two. In this case, the modulator 220 forms a PN junction in one of the branched waveguides, applies a voltage of an AC waveform to the PN junction, and generates a signal in which the phase of light is changed by changing the refractive index due to the carrier plasma effect. The modulator 220 can modulate the phase of the original signal by combining the generated signal waveform with the original signal waveform at the exit of the interferometer.

[0017] The splitter 230 splits the transmission signal Stx into a transmission signal Stx (transmission signal Stx1) for irradiating the target TG and a transmission signal Stx (transmission signal Stx2) for interfering with the return signal Srx in the coupler 260. The transmission signal Stx1 has most of the energy of the transmission signal Stx. The transmission signal Stx2 is a reference signal that has a much smaller amount of energy than the energy of the transmission signal Stx1 but has a sufficient amount of energy to interfere with the return signal Srx in the coupler 260. The return signal Srx corresponds to a signal whose phase is delayed relative to the transmission signal Stx1. The return signal Srx is generated by the transmission signal Stx being reflected by the target TG.

[0018] The splitter 230 is an element having three ports. In the splitter 230, the first port and the third port are present in the optical waveguide WG1. The second port is present in the optical waveguide WG2. The optical waveguide WG2 is disposed close to a portion of the optical waveguide WG1 between the first port and the third port. This causes the optical signal propagating through the optical waveguide WG1 to leak into the optical waveguide WG2. The optical signal leaking from the optical waveguide WG1 to the optical waveguide WG2 propagates through the optical waveguide WG2 as a transmission signal Stx2.

[0019] The circulator 240 is an element having three ports, and transmits a transmission signal Stx1 incident from a first port to a third port, and transmits a return signal Srx incident from the third port to a second port. In the circulator 240, an optical waveguide WG1 is connected to the first port, and an optical waveguide WG2 is connected to the second port. An optical waveguide extending from the antenna 250 is connected to the third port. The circulator 240, for example, rectifies an optical signal to be transmitted and an optical signal received from a Si antenna 251. In the circulator 240, the signal strength of the transmission signal and the reception signal is divided into 50% and 50% at each branch due to a structure in which an optical waveguide formed of Si branches. By handling this half of the signal, the transmission light and the reception light can be separated.

[0020] The antenna 250 is a mechanical-less scanner that does not have a driving unit. The antenna 250 transmits a transmission signal Stx1 toward the target TG via the lens 205, and receives a return signal Srx via the lens 205. The lens 205 is attached to an area (incident / exit surface S2) of the surface of the PIC board 200A that faces the Si antenna 251. The transmission signal Stx1 is emitted from the incident / exit surface S2, and the return signal Srx is incident on the incident / exit surface S2. The lens 205 is attached to the incident / exit surface S2, and the transmission signal Stx is emitted from the antenna 250 to the outside via the lens 205 and the incident / exit surface S2, and the return signal Srx is incident on the antenna 250 from the outside via the lens 205 and the incident / exit surface S2.

[0021] 3, the antenna 250 has a plurality of antenna elements (for example, four antenna elements) each of which is made up of a Si antenna 251 and a pair of heaters 252 provided on both sides of the Si antenna 251. Each antenna element extends in a common direction, and the plurality of antenna elements are arranged side by side at predetermined intervals in a direction perpendicular to the extending direction of the antenna elements.

[0022] The Si antenna 251 is composed of a diffraction grating provided on the Si layer 201. The diffraction grating is, for example, an element in which a plurality of grooves or through holes are arranged in a row on the Si layer 201 at a pitch of several hundred nm. The Si antenna 251 emits a transmission signal Stx1 having a peak at a certain position according to the pitch of the diffraction grating at a predetermined angle with respect to the surface of the Si layer 201 in accordance with the control of the controller 310. The heater 252 is a resistive element extending along the Si antenna 251. A current is applied to the resistive element of the heater 252 in accordance with the control of the controller 310, and the heater 252 heats the Si antenna 251 by the heat generated by the resistive element. In the Si antenna 251, the refractive index changes due to heating by the heater 252, and the transmission signal Stx1 is emitted at an angle according to the change in the refractive index. That is, the Si antenna 251 sweeps the transmission signal Stx1 in a predetermined external area in accordance with the control of the controller 310.

[0023] In the case where four antennas are provided, the antenna 250 further includes, for example, four optical switches 253, one for each antenna, and two optical switches 254, one for each two optical switches 253, as shown in FIG. 3. Each optical switch 253 is a switch that connects and disconnects an optical waveguide between two terminals (first terminal, second terminal). Each optical switch 254 is a switch that connects and disconnects an optical waveguide between two terminals (third terminal, fourth terminal). The antenna 250 further includes, for example, one optical switch 255 connected to the two optical switches 254, as shown in FIG. 3. Each optical switch 255 is a switch that connects and disconnects an optical waveguide between two terminals (fifth terminal, sixth terminal).

[0024] In each optical switch 253, the first terminal is coupled to the antenna body, and the second terminal is coupled to the second terminal of the other optical switch 253 and to the third terminal of the optical switch 254. In each optical switch 254, the third terminal is coupled to the second terminals of the two optical switches 253, and the fourth terminal is coupled to the fourth terminal of the other optical switch 254 and to the fifth terminal of the optical switch 255. In the optical switch 255, the fifth terminal is coupled to the fourth terminals of the two optical switches 254, and the sixth terminal is coupled to the second port of the circulator 240.

[0025] The antenna body is composed of a diffraction grating provided on the Si layer 201, for example, as shown in Figures 4 and 5. Figure 4 shows an example of a cross-sectional configuration of the antenna body in Figure 3 taken along line AA. Figure 5 shows an example of a cross-sectional configuration of the antenna body in Figure 3 taken along line BB. The diffraction grating is an element in which a plurality of grooves are arranged in a row on the Si layer 201 at a pitch of several hundred nm, for example, as shown in Figures 4 and 5. The depth of the grooves is, for example, several hundred nm, and the thickness of a portion of the Si layer 201 corresponding to the base of the diffraction grating is, for example, several hundred nm.

[0026] In the Si antenna 251, a transmission signal Stx1 having a peak at a certain position according to the pitch of the diffraction grating is emitted at a predetermined angle with respect to the surface of the Si layer 201. The heater 252 is a resistive element extending along the Si antenna 251. A current is applied to the resistive element of the heater 252 according to the control of the controller 310, and the resulting heat generated by the resistive element heats the Si antenna 251. In the Si antenna 251, the refractive index changes due to heating by the heater 252, and the transmission signal Stx1 is emitted at an angle according to the change in the refractive index.

[0027] The antenna 250 turns on and off four optical switches 253, two optical switches 254, and one optical switch 255 under the control of the controller 310. As a result, the antenna 250 emits a transmission signal Stx1 from each antenna in a predetermined direction, and receives a return signal Srx incident from the outside.

[0028] The coupler 260 is an element that generates a beat signal Sbt by interference between the transmission signal Stx2 and the return signal Srx. The frequency of the beat signal Sbt changes according to the frequency difference between the transmission signal Stx2 and the return signal Srx. The frequency difference changes according to the distance from the Si antenna 251 to the target TG. Therefore, the distance from the Si antenna 251 to the target TG can be estimated based on the frequency of the beat signal Sbt.

[0029] 6, the coupler 260 has an optical waveguide 261 for propagating a transmission signal Stx2 and an optical waveguide 262 for propagating a return signal Srx. Each of the optical waveguides 261 and 262 is, for example, a rib-type waveguide. A part of the optical waveguide 261 and a part of the optical waveguide 262 are disposed close to each other, so that the transmission signal Stx2 propagating through the optical waveguide 261 and the return signal Srx propagating through the optical waveguide 262 interfere with each other to generate a beat signal Sbt.

[0030] The detector 270 is an element that extracts a beat signal Sbt from the signals propagating from the optical waveguides 261 and 262. The detector 270 has, for example, GePDs 271 and 272 connected in series with each other, and a transimpedance amplifier 273 connected to the connection node between the GePDs 271 and 272, as shown in FIG.

[0031] The GePD 271 is, for example, a PIN photodiode coupled to the optical waveguide 261 as shown in Fig. 7. The GePD 272 is, for example, a PIN photodiode coupled to the optical waveguide 262 as shown in Fig. 7. The GePDs 271 and 272 each have, for example, a Si terrace portion 71 connected to the optical waveguides 261 and 262, and a p-type Si layer 72 formed by ion-implanting B into the Si terrace portion 71. The Si terrace portion 71 and the optical waveguides 261 and 262 are formed in a common Si layer 201.

[0032] The GePDs 271 and 272 further include, for example, an island-shaped i-type Ge layer 73 and a two-dimensionally grown i-type Ge layer 74 formed on a p-type Si layer 72, and an n-type Ge layer 75 formed by ion-implanting P into the two-dimensionally grown i-type Ge layer 74. A stacked body including the p-type Si layer 72, the island-shaped i-type Ge layer 73, the two-dimensionally grown i-type Ge layer 74, and the n-type Ge layer 75 constitutes a PIN photodiode. In this PIN photodiode, the island-shaped i-type Ge layer 73, which effectively becomes p-type and does not form a depletion layer, is thin, and the thick two-dimensionally grown i-type Ge layer 74 becomes a depletion layer, thereby improving sensitivity.

[0033] The GePDs 271 and 272 further have, for example, an n-side electrode 76 in contact with the n-type Ge layer 75 and a p-side electrode 77 in contact with the p-type Si layer 72. The p-side electrode 77 of the GePD 271 and the n-side electrode 76 of the GePD 272 are connected by a wiring, and the wiring connecting the p-side electrode 77 of the GePD 271 and the n-side electrode 76 of the GePD 272 is connected to an input terminal of the transimpedance amplifier 273.

[0034] The transimpedance amplifier 273 performs impedance conversion on the current signals photoelectrically converted by the GePDs 271 and 272, amplifies the current signals, and outputs the beat signal Sbt as a voltage signal.

[0035] (Lower die 300) The bottom die 300 includes a controller 310, a DAC 320, an ADC 330, and a fast Fourier transform (FFT) 340, for example as shown in FIG.

[0036] The controller 310 generates, for example, control signals for controlling the laser 210, the modulator 220, the antenna 250, and the detector 270, and outputs the control signals to the DAC 320. The controller 310 further generates, for example, a control signal for controlling the ADC 330, and outputs the control signals to the ADC 330. The DAC 320 performs digital-to-analog conversion of the control signals input from the controller 310, and outputs analog control signals to the laser 210, the modulator 220, the antenna 250, and the detector 270. The ADC 330 performs digital-to-analog conversion of the beat signal Sbt input from the detector 270, and outputs the converted signal to the FFT 340. The FFT 340 performs FFT on the digital beat signal Sbt input from the ADC 330, and derives the frequency of the beat signal Sbt based on the power spectrum density obtained by the conversion. The FFT 340 outputs information about the derived frequency (frequency information) to the controller 310. The controller 310 outputs the frequency information input from the FFT 340 to the outside in accordance with external control.

[0037] The lower die 300 has a Si substrate 301, as shown in FIG. 2. Signal processing circuits, such as a controller 310, a DAC 320, an ADC 330, and an FFT 340, are formed on the Si substrate 301. An interlayer insulating film 302 is formed on the Si substrate 301. The interlayer insulating film 302 is made of a plurality of stacked SiO 2In the interlayer insulating film 302, a plurality of patterned wiring layers and vias connecting the wiring layers are formed. In the interlayer insulating film 302, wiring and vias in the signal processing circuit and wiring and vias for electrically connecting the signal processing circuit and the upper die 200 are formed. On the surface of the interlayer insulating film 302, a connection pad 303 made of Cu is exposed and joined to a connection pad 204 of the upper die 200. In view of the description in this specification, it can be said that the first substrate 200 includes one or more optical circuits that output a transmission signal Stx1 to a target (for example, a target TG) and receive a return signal Srx from the target. The one or more optical circuits may include, but are not limited to, a laser 210 and a modulator 220 (which may be integrated with each other and / or implemented on the first substrate 200), optical waveguides WG1, WG2, WG3, a splitter 230, a circulator 240, an antenna 250, a coupler 260, and / or a detector 270. Meanwhile, the second substrate 300 may include one or more electronic circuits for controlling the generation of the transmission signal Stx1 and processing the return signal Srx. The one or more electronic circuits may include a controller 310, a DAC 320, an ADS 330, and / or a FET block 340.

[0038] Manufacturing method Next, a method for manufacturing the distance measuring device 100 will be described.

[0039] 8A to 8G are cross-sectional views for explaining the manufacturing process of the distance measuring device 100. First, an SOI substrate 110 is prepared (FIG. 8A). The SOI substrate 110 is a substrate in which a BOX layer 203 and a Si layer 201 are formed in this order on a Si substrate 111. Next, the optical waveguides WG1, WG2, and WG3, the splitter 230, the circulator 240, the Si antenna 251, the coupler 260, and parts of the GePDs 271 and 272 (Si terrace portion 71 and p-type Si layer 72) are formed on the Si layer 201 of the SOI substrate 110 (FIG. 8A). Next, an interlayer insulating film 202 is formed on the SOI substrate 110 (FIG. 8B). At this time, connection pads 204 and 207 are formed in the interlayer insulating film 202.

[0040] Next, the SOI substrate 110 and the lower die 300 are bonded together with the surface S3 of the interlayer insulating film 202 and the surface S4 of the interlayer insulating film 302 facing each other (FIGS. 8C and 8D). As a result, the SOI substrate 110 and the lower die 300 are electrically connected. Next, the Si substrate 111 in the SOI substrate 110 is removed (FIG. 8E). As a result, the PIC substrate 200A is formed on the lower die 300. Next, a cutout portion 206 is formed in the PIC substrate 200A (FIG. 8F). As a result, the connection pad 207 is exposed on the bottom surface of the cutout portion 206. Next, the laser 210 is mounted on the connection pad 207 exposed on the bottom surface of the cutout portion 206 via the bump 212 (FIG. 8G). Finally, the lens 205 is installed. In this manner, the distance measuring device 100 is manufactured.

[0041] effect Next, the effects of the distance measuring device 100 will be described.

[0042] In this embodiment, in the PIC substrate 200A, the optical waveguide WG1, the splitter 230, the optical waveguides WG2 and WG3, the coupler 260, and the GePDs 271 and 272 are formed in a common Si layer 201. In addition, the ADC 330 and the detector 270 are formed in the lower die 300 (signal processing substrate). Furthermore, the PIC substrate 200A and the lower die 300 are stacked on each other and are electrically connected to each other via the joint surface S1 between the PIC substrate 200A and the lower die 300. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers. The smaller module shortens the path of the electrical signal after the GePDs 271 and 272, and reduces the intrusion of external noise into the electrical signal.

[0043] In this embodiment, a modulator 220 that generates a transmission signal Stx (chirp signal) and a Si antenna 251 that emits a transmission signal Stx1 divided from the transmission signal Stx to the outside and receives a return signal Srx from the outside are formed on the Si layer 201. This allows for a smaller size than a module in which multiple RF components are coupled via optical fibers.

[0044] In this embodiment, a chip-like laser 210 is mounted on a PIC substrate 200A, and a controller 310 for controlling the laser 210, the modulator 220, and the antenna 250 is formed on a lower die 300. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers. The smaller module shortens the propagation path of the laser light L, and the loss of the laser light L can be reduced.

[0045] In this embodiment, the PIC substrate 200A and the lower die 300 are electrically connected to each other by bonding the connection pads 204, 303 provided on the bonding surface S1 between the PIC substrate 200A and the lower die 300. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers. In addition, the reflection at the connection pads 204, 303 is expected to have the effect of increasing quantum efficiency.

[0046] In this embodiment, the laser 210 is an edge-emitting laser, and is mounted on the PIC board 200A so that the light spot of the laser 210 is at the same height as the Si layer 201 (optical waveguide WG1). The laser 210 inputs an optical signal to the modulator 220 via the end face of the optical waveguide WG1. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers.

[0047] In this embodiment, the laser 210 and the PIC substrate 200A are electrically connected to each other via bumps 212 provided between the laser 210 and the PIC substrate 200A. This allows the laser 210 to be positioned with high precision.

[0048] <2. Second embodiment> composition Fig. 9 shows a schematic configuration example of a distance measuring device 500 according to a second embodiment of the present disclosure. Fig. 10 shows a cross-sectional configuration example of the distance measuring device 500. The distance measuring device 500 corresponds to the distance measuring device 100 in which a through-hole via 403 penetrating the bonding surface S1 is used as a bonding method between the PIC substrate 200A and the lower die 300 (signal processing substrate) instead of bonding the connection pads 204, 303 to each other.

[0049] The distance measuring device 500 is an FMCW type LiDAR. The distance measuring device 500 includes an upper die 400 and a lower die 300, for example, as shown in FIG. 9. The upper die 400 and the lower die 300 are stacked on each other, for example, as shown in FIG. 10, and are electrically connected to each other via a through-hole via 403 that penetrates the bonding surface S1. That is, the upper die 400 and the lower die 300 are electrically connected to each other via the bonding surface S1 between the upper die 400 and the lower die 300, for example, as shown in FIG. 10.

[0050] (Upper die 400) 9, the upper die 400 includes a laser 210, a modulator 220, a splitter 230, a circulator 240, an antenna 250, a coupler 260, and a detector 270. In the upper die 400, the modulator 220, the splitter 230, the circulator 240, the antenna 250, the coupler 260, and the detector 270 are formed in a PIC substrate 400A.

[0051] The laser 210 is mounted on the PIC substrate 400A so that the laser light L is incident on an end face (optical waveguide WG1) of the PIC substrate 400A. A cutout portion 406 is formed in the PIC substrate 400A, and the laser 210 is mounted on a connection pad 408 provided on the bottom face of the cutout portion 406. The electrode of the laser 210 and the connection pad 408 are made of, for example, Cu (copper), and are joined to each other via a bump 212 made of Cu.

[0052] 10, the PIC substrate 400A has a Si layer 201, an insulating layer 401 and an interlayer insulating film 402 sandwiching the Si layer 201. The Si layer 201 is obtained by removing the Si substrate 111 and the BOX layer 203 from the SOI substrate 110. The insulating layer 401 is a layer formed on the SOI substrate 110, and is made of SiO 2 The interlayer insulating film 402 is a layer formed on the Si layer 201, and is made up of a plurality of stacked SiO 2 A plurality of patterned wiring layers and vias connecting the wiring layers to each other are formed within the layer.

[0053] The surface of the insulating layer 401 serves as the bottom surface of the upper die 400. The surface of the insulating layer 401 is in contact with the upper surface of the lower die 300 (the interlayer insulating film 302). The surface of the interlayer insulating film 402 serves as the upper surface of the upper die 400. Of the surface of the interlayer insulating film 402, a region facing the Si antenna 251 serves as the incident / exit surface S2.

[0054] The PIC board 400A is provided with through-hole vias 403 and 407. The through-hole vias 403 and 407 are made of a metal member extending in the thickness direction of the PIC board 400A.

[0055] The through-hole via 403 penetrates a part of the interlayer insulating film 402, the Si layer 201, and the insulating layer 401, and further penetrates the bonding surface S1 and a part of the interlayer insulating film 302. The top of the through-hole via 403 is connected to a wiring layer (e.g., wiring layer 404, etc.) formed in the interlayer insulating film 402, and the bottom of the through-hole via 403 is connected to the wiring layer formed in the interlayer insulating film 302. The through-hole via 403 electrically connects the output terminal of the detector 270 and the input terminal of the ADC 330.

[0056] The through-hole via 407 penetrates the insulating layer 401, and further penetrates the bonding surface S1 and a part of the interlayer insulating film 302. The top of the through-hole via 407 is connected to the connection pad 408, and the bottom of the through-hole via 407 is connected to the wiring layer formed in the interlayer insulating film 302. The through-hole via 407 electrically connects the laser 210 and the output end of the DAC 320.

[0057] 11, the PIC substrate 400A may be provided with one or more light shielding portions 405 surrounding the GePDs 271, 272 in a plan view. The one or more light shielding portions 405 are formed of vias in the interlayer insulating film 402, for example. The one or more light shielding portions 405 prevent (or reduce) light leaking from the Si antenna 251 and hot carrier emission from the lower die 300 from entering the GePDs 271, 272.

[0058] 10, the PIC substrate 400A may be provided with a light shielding portion 409 that covers the GePDs 271, 272 in a plan view between the GePDs 271, 272 and the surface of the interlayer insulating film 402. The light shielding portion 409 is formed of, for example, a wiring layer in the interlayer insulating film 402. The light shielding portion 409 prevents (or reduces) external light from being incident on the GePDs 271, 272.

[0059] 10, the lower die 300 may be provided with a light-shielding layer 306 between the GePDs 271, 272 and the Si substrate 301 and at a position facing the GePDs 271, 272. The light-shielding layer 306 is, for example, formed of a wiring layer in the interlayer insulating film 302. The light-shielding layer 306 prevents (or reduces) hot carrier light emission from the lower die 300 from being incident on the GePDs 271, 272.

[0060] Manufacturing method Next, a method for manufacturing the distance measuring device 500 will be described.

[0061] 12A to 12G are cross-sectional views for explaining a manufacturing process of the distance measuring device 500. First, an SOI substrate 110 on which an insulating layer 401 is formed, and a lower die 300 are prepared (FIG. 12A). Next, the SOI substrate 110 and the lower die 300 are bonded together with a surface S3 of the insulating layer 401 and a surface S4 of the interlayer insulating film 302 facing each other (FIGS. 12A and 12B). At this time, unlike the above embodiment, no electrical connection is formed between the SOI substrate 110 and the lower die 300.

[0062] Next, the Si substrate 111 and the BOX layer 203 are removed to expose the Si layer 201 (FIG. 12C). Next, an interlayer insulating film 402 is formed on the surface of the Si layer 201 (FIG. 12D). This forms a PIC substrate 400A on the lower die 300. Next, a through hole is formed penetrating the interlayer insulating film 402, the Si layer 201, the insulating layer 401, the bonding surface S1, and a part of the interlayer insulating film 302, and then a metal member is embedded in the through hole to form a through hole via 403 (FIG. 12E). Furthermore, a wiring layer 404 is formed to electrically connect the through hole via 403 to the output terminal of the detector 270.

[0063] Next, the cutout portion 406 is formed (FIG. 12F). Then, a through hole penetrating the insulating layer 401 and a part of the interlayer insulating film 302 is formed on the bottom surface of the cutout portion 406, and then a metal member is embedded in the through hole to form a through hole via 407 (FIG. 12F). Next, a connection pad 408 in contact with the through hole via 407 is formed on the bottom surface of the cutout portion 406, and further, the laser 210 is mounted on the connection pad 408 via the bump 212 (FIG. 12G). Finally, the lens 205 is installed. In this manner, the distance measuring device 500 is manufactured.

[0064] effect Next, the effects of the distance measuring device 500 will be described.

[0065] In this embodiment, in the PIC substrate 400A, the optical waveguide WG1, the splitter 230, the optical waveguides WG2 and WG3, the coupler 260, and the GePDs 271 and 272 are formed in a common Si layer 201. In addition, the ADC 330 and the detector 270 are formed in the lower die 300 (signal processing substrate). Furthermore, the PIC substrate 400A and the lower die 300 are stacked on each other and are electrically connected to each other via the joint surface S1 between the PIC substrate 400A and the lower die 300. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers. The smaller module shortens the path of the electrical signal after the GePDs 271 and 272, and reduces the intrusion of external noise into the electrical signal.

[0066] In this embodiment, a modulator 220 that generates a transmission signal Stx (chirp signal) and a Si antenna 251 that emits a transmission signal Stx1 divided from the transmission signal Stx to the outside and receives a return signal Srx from the outside are formed on the Si layer 201. This allows for a smaller size than a module in which multiple RF components are coupled via optical fibers.

[0067] In this embodiment, a chip-like laser 210 is mounted on a PIC substrate 400A, and a controller 310 for controlling the laser 210, the modulator 220, and the antenna 250 is formed on the lower die 300. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers. The smaller module shortens the propagation path of the laser light L, and the loss of the laser light L can be reduced.

[0068] In this embodiment, the PIC substrate 400A and the lower die 300 are electrically connected by through-hole vias 403 that penetrate the bonding surface S1 between the PIC substrate 400A and the lower die 300. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers.

[0069] In this embodiment, the laser 210 is an edge-emitting laser, and is mounted on the PIC board 400A so that the light spot of the laser 210 is at the same height as the Si layer 201 (optical waveguide WG1). The laser 210 inputs an optical signal to the modulator 220 via the end face of the optical waveguide WG1. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers.

[0070] In this embodiment, the laser 210 and the PIC substrate 400A are electrically connected to each other via bumps 212 provided between the laser 210 and the PIC substrate 400A. This allows the laser 210 to be positioned with high precision.

[0071] <3. Third embodiment> composition Fig. 13 shows a schematic configuration example of a distance measuring device 600 according to a third embodiment of the present disclosure. Fig. 14 shows a cross-sectional configuration example of the distance measuring device 600. The distance measuring device 600 is an FMCW type LiDAR. The distance measuring device 600 includes, for example, a lower die 700 and an upper chip 800 (signal processing board) as shown in Fig. 13.

[0072] 14, the lower die 700 and the upper chip 800 are stacked on top of each other and electrically connected to each other via a bonding surface S1 between the lower die 700 and the upper chip 800. The upper chip 800 is in the form of a chip smaller in size than the PIC substrate 700A included in the lower die 700, and is mounted on the surface of the PIC substrate 700A. For example, the upper chip 800 has a footprint (e.g., surface area) smaller than the footprint of the lower die 700 in a plan view.

[0073] (Lower die 700) 13, the lower die 700 includes the laser 210, the modulator 220, the splitter 230, the circulator 240, the antenna 250, the coupler 260, and the detector 270. In the lower die 700, the modulator 220, the splitter 230, the circulator 240, the antenna 250, the coupler 260, and the detector 270 are formed in a PIC substrate 700A.

[0074] The laser 210 is mounted on the PIC substrate 700A so that the laser light L is incident on an end face (optical waveguide WG1) of the PIC substrate 700A. The laser 210 is mounted on the PIC substrate 700A so that the light spot of the laser 210 is at the same height as the Si layer 201 (optical waveguide WG1). A cutout portion 701 is formed in the PIC substrate 700A, and the laser 210 is mounted on a connection pad 702 provided on the bottom surface of the cutout portion 701. The electrode of the laser 210 and the connection pad 702 are made of, for example, Cu (copper), and are joined to each other via a bump 212 made of Cu.

[0075] 14, the PIC substrate 700A is a substrate in which a BOX layer 203, a Si layer 201, and an interlayer insulating film 202 are laminated in this order on a Si substrate 111. The Si substrate 111, the BOX layer 203, and the Si layer 201 constitute an SOI substrate 110. The interlayer insulating film 202 is a layer formed on the SOI substrate 110, and is a layer formed of a plurality of laminated SiO 2In the structure, a plurality of patterned wiring layers and vias connecting the wiring layers are formed in the layers. The surface of the interlayer insulating film 202 is the upper surface of the lower die 700 and is in contact with the bottom surface of the upper chip 800 (interlayer insulating film 302). A connection pad 204 made of Cu is exposed on the surface of the interlayer insulating film 202. Meanwhile, a connection pad 303 made of Cu is exposed on the upper surface of the upper chip 800 (interlayer insulating film 302). The connection pad 204 and the connection pad 303 are bonded to each other. As a result, the PIC substrate 700A and the upper chip 800 are bonded to each other at the upper surface of the PIC substrate 700A and the bottom surface of the upper chip 800. In FIG. 14, the bonding surface between the upper surface of the lower die 700 and the bottom surface of the upper chip 800 (interlayer insulating film 302) is expressed as S1. The bottom surface of the Si substrate 111 is the bottom surface of the lower die 700 and is the input / output surface S2.

[0076] (Top tip 800) The upper chip 800 has, for example, a controller 310, a DAC 320, an ADC 330, and an FFT 340, as shown in FIG. 13. The upper chip 800 has, for example, a Si substrate 301, as shown in FIG. 14. Signal processing circuits, such as the controller 310, the DAC 320, the ADC 330, and the FFT 340, are formed on the Si substrate 301. An interlayer insulating film 302 is formed on the Si substrate 301. The interlayer insulating film 302 is made of a plurality of stacked SiO 2 In the interlayer insulating film 302, a plurality of patterned wiring layers and vias connecting the wiring layers are formed. In the interlayer insulating film 302, wiring and vias in the signal processing circuit and wiring and vias for electrically connecting the signal processing circuit and the lower die 700 are formed. On the surface of the interlayer insulating film 302, a connection pad 303 made of Cu is exposed and is bonded to a connection pad 204 of the lower die 700. The laser 210 is electrically connected to the upper chip 800 by, for example, a bonding wire.

[0077] The lower die 700 is provided with a marker 703. Meanwhile, the upper chip 800 is provided with a marker 304. The markers 703 and 304 are for positioning the upper chip 800 when mounting the upper chip 800 on the lower die 700. The marker 703 is a part of a wiring layer formed in the interlayer insulating film 202. The marker 304 is a part of a wiring layer formed in the interlayer insulating film 302. For example, as shown in FIG. 14, the markers 703 and 304 are arranged in a region not facing the GePDs 271 and 272 in a plan view in order to ensure visibility with infrared light. The marker 703 may constitute a part of the connection pad 204. Also, the marker 304 may constitute a part of the connection pad 303.

[0078] effect Next, the effects of the distance measuring device 600 will be described.

[0079] In this embodiment, in the PIC substrate 700A, the optical waveguide WG1, the splitter 230, the optical waveguides WG2 and WG3, the coupler 260, and the GePDs 271 and 272 are formed in a common Si layer 201. In addition, the ADC 330 and the detector 270 are formed in the upper chip 800 (signal processing substrate). Furthermore, the PIC substrate 700A and the upper chip 800 are stacked on each other and are electrically connected to each other via the joint surface S1 between the PIC substrate 700A and the upper chip 800. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers. The smaller module shortens the path of the electrical signal after the GePDs 271 and 272, and can reduce the intrusion of external noise into the electrical signal.

[0080] In this embodiment, a modulator 220 that generates a transmission signal Stx (chirp signal) and a Si antenna 251 that emits a transmission signal Stx1 divided from the transmission signal Stx to the outside and receives a return signal Srx from the outside are formed on the Si layer 201. This allows for a smaller size than a module in which multiple RF components are coupled via optical fibers.

[0081] In this embodiment, a chip-like laser 210 is mounted on a PIC substrate 700A, and a controller 310 that controls the laser 210, the modulator 220, and the antenna 250 is formed on an upper chip 800. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers. The smaller module shortens the propagation path of the laser light L, and the loss of the laser light L can be reduced.

[0082] In this embodiment, the PIC substrate 700A and the upper chip 800 are electrically connected to each other by bonding together the connection pads 204, 303 provided on the bonding surface S1 between the PIC substrate 700A and the upper chip 800. This allows for a smaller size compared to a module in which multiple RF components are coupled via optical fibers.

[0083] In this embodiment, the laser 210 is an edge-emitting laser, and is mounted on the PIC board 700A so that the light spot of the laser 210 is at the same height as the Si layer 201 (optical waveguide WG1). The laser 210 inputs an optical signal to the modulator 220 via the end face of the optical waveguide WG1. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers.

[0084] In this embodiment, the lower die 700 is provided with a marker 703, and the upper chip 800 is provided with a marker 304. This allows, for example, infrared light to be irradiated onto the markers 703 and 304, and the upper chip 800 to be mounted on the lower die 700 while checking the positions of the markers 703 and 304. Thus, the upper chip 800 can be positioned on the lower die 700 with high precision. As will be appreciated, the distance measuring device 600 of FIG. 13 and FIG. 14 can be formed by a chip-on-wafer (CoW) wafer process. In a CoW process, multiple upper chips 800 are formed on a single silicon wafer and diced to form individual upper chips 800. The individual upper chips 800 are then each tested (e.g., to ensure proper electrical function of the transistors). Only the upper chips 800 that pass the test are placed on a support substrate (e.g., 301), and then bonded to another wafer (e.g., 111) including multiple PIC substrates 700A to form multiple distance measuring devices 600. The bonded structure may then be diced to form individual ranging devices 600, each having an upper chip 800 bonded to a lower die 700. As will be appreciated, the CoW process may increase theoretical yield (by reducing dead space due to defective elements) and reduce the risk of producing defective ranging devices compared to a wafer-on-wafer (WoW) process, in which a wafer of upper dies 200 is bonded to a wafer of lower dies 300 prior to dicing and testing of the lower die 300 (see FIG. 2 for an embodiment of a ranging device formed by a WoW process).

[0085] <4. Modification of the third embodiment> 15 and 16 show a modified example of the schematic configuration of the distance measuring device 600. For example, as shown in FIG. 15, a wiring layer 704 may be formed in the interlayer insulating film 202 at a position facing the marker 703. Also, as shown in FIG. 16, a GePD 705 may be formed in the Si layer 201 at a position facing the marker 703. In this case, for example, when infrared rays are irradiated to the markers 703 and 304 from the upper chip 800 side, the infrared rays are reflected by the wiring layer 704 and the GePD 705, so that the upper chip 800 can be positioned on the lower die 700 with high accuracy.

[0086] 17, a groove 709 may be formed in a PIC substrate 700A, and a wiring layer 704 may be provided on the bottom surface of the groove 709. In this case, an upper chip 800 may be mounted in the groove 709, and the connection pads 303 of the upper chip 800 may be electrically connected to the wiring layer 704 in the groove 709. In this case, the size can be reduced by the amount that the upper chip 800 is embedded in the groove 709.

[0087] <5. Fourth embodiment> composition Fig. 18 shows a schematic configuration example of a distance measuring device 1100 according to a fourth embodiment of the present disclosure. Fig. 19 shows a cross-sectional configuration example of the distance measuring device 1100. The distance measuring device 1100 uses vias 1210 and 1230 as electrical connections between elements such as a laser 210, a modulator 220, an antenna 250, and a detector 270 and signal processing circuits such as a controller 310, a DAC 320, an ADC 330, and an FFT 340. The lower ends of the vias 1210 and 1230 are connected to the gates and diffusion regions (source / drain) of transistors used in the signal processing circuits, and the upper ends of the vias 1210 and 1230 are connected to wiring layers provided in an interlayer insulating film.

[0088] The distance measuring device 1100 is an FMCW type LiDAR. The distance measuring device 1100 includes an upper layer 1200 and a lower layer 1300, for example, as shown in FIG. 18. For example, as shown in FIG. 19, the upper layer 1200 is formed on the lower layer 1300, and the wiring layer formed on the upper layer 1200 and the gate and diffusion region (source / drain) of the transistor formed on the lower layer 1300 are electrically connected to each other through vias 1210 and 1230. That is, the upper layer 1200 and the lower layer 1300 are electrically connected to each other through the surfaces where the upper layer 1200 and the lower layer 1300 are in contact with each other, for example, as shown in FIG. 19.

[0089] (Top layer 1200) 18, the upper layer 1200 includes a laser 210, a modulator 220, a splitter 230, a circulator 240, an antenna 250, a coupler 260, and a detector 270. In the upper layer 1200, the modulator 220, the splitter 230, the circulator 240, the antenna 250, the coupler 260, and the detector 270 are formed in the PIC layer 1200A.

[0090] The laser 210 is mounted on the PIC layer 1200A so that the laser light L is incident on an end face (optical waveguide WG1) of the PIC layer 1200A. A cutout portion 406 is formed in the PIC layer 1200A, and the laser 210 is mounted on a connection pad 408 provided on the bottom face of the cutout portion 406. The electrode of the laser 210 and the connection pad 408 are made of, for example, Cu (copper), and are joined to each other via a bump 212 made of Cu.

[0091] 19, the PIC layer 1200A has a Si layer 201, an insulating layer 401 sandwiching the Si layer 201, and an interlayer insulating film 402. The insulating layer 401 is a layer formed on the lower layer 1300, and is made of SiO 2 The Si layer 201 is a layer formed on the insulating layer 401. The interlayer insulating film 402 is a layer formed on the Si layer 201, and is made of a plurality of stacked SiO2 In the layer, a plurality of patterned wiring layers and vias connecting the wiring layers are formed. The surface of the interlayer insulating film 402 is the upper surface of the PIC layer 1200A. Of the surface of the interlayer insulating film 402, a region facing the Si antenna 251 is the input / output surface S2.

[0092] The PIC layer 1200A is provided with vias 1210 and 1230. The vias 1210 and 1230 are formed of metal members extending in the thickness direction of the PIC layer 1200A.

[0093] The via 1210 penetrates a part of the interlayer insulating film 402, the Si layer 201, and the insulating layer 401, and further penetrates the insulating layer 305 (described later) of the lower layer 1300. The top of the via 1210 is connected to a wiring layer (e.g., the wiring layer 1220, etc.) formed in the interlayer insulating film 402, and the bottom of the via 1210 is connected to the gate and diffusion region (source / drain) of a transistor formed in the Si substrate 301 of the lower layer 1300. The via 1210 electrically connects the output terminal of the detector 270 and the input terminal of the ADC 330.

[0094] The via 1230 penetrates the insulating layer 401 and further penetrates the insulating layer 305 (described later) of the lower layer 1300. The top of the via 1230 is connected to the connection pad 408, and the bottom of the via 1230 is connected to the gate and diffusion region (source / drain) of a transistor formed in the Si substrate 301 of the lower layer 1300. The via 1230 electrically connects the laser 210 and the output end of the DAC 320.

[0095] The lower layer 1300 includes, for example, a controller 310, a DAC 320, an ADC 330, and an FFT 340, as shown in FIG.

[0096] The lower layer 1300 has, for example, a Si substrate 301 as shown in FIG. 19. Signal processing circuits, such as a controller 310, a DAC 320, an ADC 330, and an FFT 340, are formed on the Si substrate 301. An insulating layer 305 is formed on the Si substrate 301. The insulating layer 305 is made of SiO 2 It is made up of layers.

[0097] Manufacturing method Next, a method for manufacturing the distance measuring device 1100 will be described.

[0098] 20A to 20F are cross-sectional views for explaining the manufacturing process of the distance measuring device 1100. First, a lower layer 1300 in which an insulating layer 305 is formed on a Si substrate 301 is prepared (FIG. 20A). Next, a Si layer 201 is formed on the lower layer 1300, and optical waveguides WG1, WG2, and WG3, splitter 230, circulator 240, Si antenna 251, coupler 260, and parts of GePDs 271 and 272 (Si terrace portion 71, p-type Si layer 72) are formed on the Si layer 201 (FIG. 20B).

[0099] Next, an insulating layer 402a is formed on the Si layer 201, and then a through hole is formed penetrating the insulating layer 402a, the Si layer 201, the insulating layer 401, and the insulating layer 305, and a metal member is embedded in the through hole to form a via 1210 (FIG. 20C). Next, an interlayer insulating film is formed on the insulating layer 402a, thereby forming an interlayer insulating film 402 on the Si layer 201 (FIG. 20D). At this time, a wiring layer 1220 is formed so as to contact the top of the via 1210. In this manner, a PIC layer 1200A is formed on the lower layer 1300.

[0100] Next, the cutout portion 406 is formed (FIG. 20E). Subsequently, a through hole penetrating the insulating layers 401, 305 is formed on the bottom surface of the cutout portion 406, and then a metal member is embedded in the through hole to form a via 1230 (FIG. 20E). Next, a connection pad 408 in contact with the via 1230 is formed on the bottom surface of the cutout portion 406, and further, the laser 210 is mounted on the connection pad 408 via the bump 212 (FIG. 20F). Finally, the lens 205 is installed. In this manner, the distance measuring device 1100 is manufactured.

[0101] effect Next, the effects of the distance measuring device 1100 will be described.

[0102] In this embodiment, in the PIC layer 1200A, the optical waveguide WG1, the splitter 230, the optical waveguides WG2 and WG3, the coupler 260, and the GePDs 271 and 272 are formed in a common Si layer 201. Also, the ADC 330 and the detector 270 are formed in the lower layer 1300 (signal processing substrate). Furthermore, the PIC layer 1200A is formed on the lower layer 1300, and the lower layer 1300 and the PIC layer 1200A are electrically connected to each other via the surfaces where the lower layer 1300 and the PIC layer 1200A are in contact with each other. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers. The smaller module shortens the path of the electrical signal after the GePDs 271 and 272, and can reduce the intrusion of external noise into the electrical signal.

[0103] In this embodiment, a modulator 220 that generates a transmission signal Stx (chirp signal) and a Si antenna 251 that emits a transmission signal Stx1 divided from the transmission signal Stx to the outside and receives a return signal Srx from the outside are formed on the Si layer 201. This allows for a smaller size than a module in which multiple RF components are coupled via optical fibers.

[0104] In this embodiment, a chip-like laser 210 is mounted on the PIC layer 1200A, and a controller 310 that controls the laser 210, the modulator 220, and the antenna 250 is formed on the lower layer 1300. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers. The smaller module shortens the propagation path of the laser light L, and the loss of the laser light L can be reduced.

[0105] In this embodiment, the PIC layer 1200A and the lower layer 1300 are electrically connected by vias 1210 that penetrate the surfaces where the PIC layer 1200A and the lower layer 1300 contact each other. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers.

[0106] In this embodiment, the laser 210 is an edge-emitting laser, and is mounted on the PIC layer 1200A so that the light spot of the laser 210 is at the same height as the Si layer 201 (optical waveguide WG1). The laser 210 inputs an optical signal to the modulator 220 via the end face of the optical waveguide WG1. This allows for a smaller module than a module in which multiple RF components are coupled via optical fibers.

[0107] In this embodiment, the laser 210 and the PIC layer 1200A are electrically connected to each other via a bump 212 provided between the laser 210 and the PIC layer 1200A. This allows the laser 210 to be positioned with high precision.

[0108] <6. Modification of the Fourth Embodiment> FIG. 21 shows a modified example of the schematic configuration of the distance measuring device 1100. In this modified example, the lower layer 1300 may have an STI (shallow trench isolation) section 1240 at a location facing the Si antenna 251. The STI section 1240 has a depth that reaches, for example, from the surface of the insulating layer 305 to the Si substrate 301. In the lower layer 1300, a trench is formed with a depth that reaches from the surface of the insulating layer 305 to the Si substrate 301, and an insulating material is filled in the trench to form the STI section 1240. An example of the insulating material used for the STI section 1240 is silicon oxide. In this case, a part of the transmission signal Stx1 emitted from the Si antenna 251 is reflected by the lower layer 1300, and the occurrence of a side lobe (beam spread) in the transmission signal Stx1 can be suppressed.

[0109] 7. Modifications of each embodiment Modifications of the above-described embodiments will be described below. In the following modifications, components common to the above-described embodiments will be denoted by the same reference numerals.

[0110] [Variation A] In each of the above-mentioned embodiments and their modified examples, for example, as shown in FIG. 22, a tapered optical waveguide 208 having an end face on a surface continuous with the end face of the optical waveguide WG1 may be provided in the PIC substrate 200A. The optical waveguide 208 is formed of, for example, SiN or SiON, and is formed by an etching process using a grayscale resist. In this case, the laser 210 may be mounted on the PIC substrate 200A so that the light spot (active layer 211) of the laser 210 is in the same layer as the Si layer 201 (optical waveguide WG1) and the optical waveguide 208. As a result, the positioning accuracy of the laser 210 can be relaxed.

[0111] 22, 23, and 24 show a modified example of a method of mounting the laser 210 on the PIC board 200A. In this modified example, the laser 210 may be mounted on the PIC board 200A via solder 213, as shown in FIG. 22. The laser 210 may be mounted on the PIC board 200A by bonding an electrode (Cu electrode 215) of the laser 210 to a connection pad 207 made of Cu, as shown in FIG. 23. The laser 210 may be mounted on the connection pad 207 embedded in the PIC board 200A via a bump 212, as shown in FIG. 24. In this manner, in this modified example, various methods can be adopted as a method of mounting the laser 210 on the PIC board 200A.

[0112] [Variation B] In each of the above-described embodiments and the modified examples, a laser 280 that emits laser light L in the stacking direction may be used instead of the laser 210 that emits the laser light L from the end face. The laser 280 is a vertical cavity surface emitting laser (VCSEL). The laser 280 includes an active layer 281 and a pair of distributed Bragg reflector (DBR) layers that sandwich the active layer 281 in the thickness direction, as shown in FIG. 25, for example.

[0113] 25, the PIC substrate 200A may have an optical coupler 209 that guides the laser light L emitted from the laser 280 to the optical waveguide WG1 at a position facing the laser 280. In this case, the optical coupler 209 is formed of, for example, a diffraction grating formed in the Si layer 201.

[0114] PIC substrate 700A may have optical coupler 209, for example, as shown in Fig. 26. In this case, Si substrate 111 may have opening 111a for fitting laser 280, for example, at a location facing laser 280. In this case, laser 280 is fitted in opening 111a. Resin or the like for fixing laser 280 may be provided in opening 111a.

[0115] In this way, a vertical cavity surface emitting laser is used as a light source for emitting an optical signal, and the optical signal emitted from the surface emitting laser is guided to the optical waveguide WG1 by using the optical coupler 209. This allows the optical waveguide WG1 and the surface emitting laser to be self-aligned, reducing optical loss due to misalignment and improving coupling efficiency.

[0116] In this modification, an optical element (e.g., a prism 290) may be provided that refracts the laser light L emitted from the laser 280 and makes it obliquely incident on the optical coupler 209. The prism 290 is formed between the laser 280 and the optical coupler 209. For example, the prism 290 may be formed in the interlayer insulating film 202 as shown in FIG. 27. This allows the laser light L to be efficiently propagated to the Si antenna 251 in the optical coupler 209. As a result, the optical coupling between the optical waveguide WG1 and the surface-emitting laser can be further improved.

[0117] In this modification, the laser 280 may be configured to emit the laser light L in a direction obliquely intersecting with the lamination direction. In the laser 280, for example, a composite photonic crystal layer in which the period difference between two types of photonic crystals is continuously changed is formed adjacent to the active layer 281. In addition, in the laser 280, for example, divided electrodes are arranged in multiple stages. With this, by simultaneously driving several adjacent electrodes among the multiple electrodes arranged in multiple stages and shifting the driving positions of the electrodes one by one, it is possible to selectively excite and oscillate photonic crystal (resonator) parts having various lattice constant differences. As a result, it is possible to change the emission angle of the laser light L depending on the excitation position.

[0118] In this modification, the laser light L is obliquely incident on the optical coupler 209 as shown in Fig. 28. This allows the laser light L to be efficiently propagated to the Si antenna 251 in the optical coupler 209. As a result, the optical coupling between the optical waveguide WG1 and the surface-emitting laser can be further improved.

[0119] [Variation C] In each of the above-described embodiments and the modified examples thereof, a gap may be provided at a location in contact with the Si antenna 251. For example, as shown in FIG. 29, a gap 706 (e.g., an air gap) may be formed in both the interlayer insulating film 202 and the BOX layer 203 in the PIC substrate 700A. The gap 706 is formed at a location facing the Si antenna 251. By forming the gap 706 in this manner, it becomes possible to make the swing angle from the Si antenna 251 approximately 1.5 times wider than when there is no gap.

[0120] In this modification, the interlayer insulating film 202 may have a wall 707 at a location in contact with the void 706. Also, in this modification, the BOX layer 203 may have a wall 708 at a location in contact with the void 706. The walls 707 and 708 are made of, for example, a material (for example, SiN) that is resistant to an etchant suitable for etching Si.

[0121] Next, a method for manufacturing the distance measuring device according to this modification will be described. First, an SOI substrate 110 having a wall portion 707 provided on the BOX layer 203 is prepared (FIG. 30A). Next, the optical waveguides WG1, WG2, and WG3, the splitter 230, the circulator 240, the Si antenna 251, the coupler 260, and parts of the GePDs 271 and 272 (Si terrace portion 71 and p-type Si layer 72) are formed on the Si layer 201 of the SOI substrate 110 (FIG. 30A). Next, an interlayer insulating film 202 is formed on the SOI substrate 110 (FIG. 30B). Next, a wall portion 707 is formed on the interlayer insulating film 202 (FIG. 30C).

[0122] Next, a resist layer 2100 having an opening 2110 is formed on the surface of the interlayer insulating film 202 at a location surrounded by the wall portion 707 (FIG. 30D). Next, the interlayer insulating film 202 and the BOX layer 203 are selectively etched using an etchant suitable for etching Si. As a result, a gap 706 is formed in both the interlayer insulating film 202 and the BOX layer 203. In this manner, the distance measuring device according to this modification is manufactured.

[0123] In this modification, for example, as shown in Fig. 31 , a module lens 710 may be provided in which lens 205 is laminated on a Si substrate 720. In this case, gap 706 may be sealed with module lens 710. In this way, when module lens 710 is used, lens 205 can be disposed above Si antenna 251 via gap 706.

[0124] [Variation D] In each of the above-described embodiments and the modified examples, a void may be provided only in either the upper or lower region in contact with the Si antenna 251. For example, as shown in FIG. 32, in the PIC substrate 200A, a void 258 (e.g., an air gap) may be formed only in the interlayer insulating film 202. The void 258 is formed in a location facing the Si antenna 251.

[0125] In this modification, the interlayer insulating film 202 may be provided with a wall portion 257 at a location in contact with the void 258. The wall portion 257 may be made of, for example, Si or SiO. 2 The insulating layer 11 is made of a material (eg, SiN) that is resistant to an etchant suitable for etching the insulating layer 11.

[0126] Next, a manufacturing method of the distance measuring device according to this modification will be described. First, an SOI substrate 110 is prepared. Next, an interlayer insulating film 202 is formed on the SOI substrate 110 (FIG. 33A). Next, a groove is formed penetrating the interlayer insulating film 202, and then a wall portion 257 is formed to fill the groove (FIG. 33B). Next, an interlayer insulating film 202 is formed to fill the wall portion 257 (FIG. 33C).

[0127] Next, the SOI substrate 110 and the lower die 300 are bonded together with the surfaces of the interlayer insulating film 202 and the interlayer insulating film 302 facing each other (FIG. 33D). This electrically connects the SOI substrate 110 and the lower die 300. Next, the Si substrate 111 and the BOX layer 203 in the SOI substrate 110 are removed (FIG. 33E). This exposes the Si layer 201. Next, the optical waveguides WG1, WG2, and WG3, the splitter 230, the circulator 240, and the coupler 260 and parts of the GePDs 271 and 272 (Si terrace portion 71, p-type Si layer 72) are formed in the Si layer 201 of the SOI substrate 110 (FIG. 33E).

[0128] Next, a resist layer 2200 having an opening 2210 formed therein is formed on the surface of the Si layer 201 (FIG. 33F). Next, the Si layer 201 is selectively etched using an etchant suitable for etching Si, with the resist layer 2200 as a mask (FIG. 33G). As a result, a Si antenna 251 is formed in the Si layer 201. Next, a SiO 2 By selectively etching the interlayer insulating film 202 using an etchant suitable for etching, a gap 258 is formed directly under the Si antenna 251 (FIG. 33H). Then, the resist layer 2200 is removed (FIG. 33I). In this manner, the distance measuring device according to this modification is manufactured.

[0129] In this modification, in the PIC substrate 200A, a gap 258 is formed only in the interlayer insulating film 202. The gap 258 is formed in a location facing the Si antenna 251. By forming the gap 258 in this manner, it becomes possible to make the swing angle from the Si antenna 251 approximately 1.5 times wider than when there is no gap.

[0130] 34, for example, a module lens 900 may be provided in which lens 205 is laminated on a Si substrate 910. In this case, gap 258 may be sealed with module lens 900. In this manner, when module lens 900 is used, lens 205 can be disposed on Si layer 201 via gap 258.

[0131] [Variation E] In each of the above-mentioned embodiments and the modified examples, a reflective layer that reflects the reception signal Srx transmitted through the Si antenna 251 toward the Si antenna 251 may be provided. For example, as shown in FIG. 35, in the PIC substrate 200A, a reflective layer 204a may be formed in the interlayer insulating film 202. The reflective layer 204a is formed in a position of the interlayer insulating film 202 facing the Si antenna 251. The reflective layer 204a reflects the return signal Srx and causes the reflected light to enter the Si antenna 251. At this time, a wiring layer 303a that is bonded to the reflective layer 204a is formed in the lower die 300. The reflective layer 204a and the wiring layer 303a are made of, for example, Cu. In this way, by providing the reflective layer 204a, it is expected that the quantum efficiency will be improved by the reflection of the reflective layer 204a.

[0132] [Variation F] In each of the above embodiments and their modifications, the laser and the signal processing board may be connected by a bonding wire.

[0133] For example, as shown in FIG. 36, in the distance measuring device 100, a through hole 308 is provided that reaches from the bottom surface of the cutout portion 206 of the PIC substrate 200A to the wiring layer 307 in the interlayer insulating film 302 of the lower die 300. Furthermore, a bonding wire 309 is provided that is connected to the surface of the wiring layer 307 exposed at the bottom surface of the through hole 308 and the surface of the electrode 214 of the edge-emitting laser 210. The wiring layer 307 and the electrode 214 are made of, for example, Au (gold). The bonding wire 309 is made of, for example, Au (gold). In this case, the installation location of the laser 210 can be given a degree of freedom.

[0134] For example, as shown in FIG. 37, in the distance measuring device 100, a through hole 308 is provided that reaches from the bottom surface of the cutout portion 203a of the PIC substrate 200A to the wiring layer 307 in the interlayer insulating film 302 of the lower die 300. Furthermore, a bonding wire 309 is provided that is connected to the surface of the wiring layer 307 exposed at the bottom surface of the through hole 308 and the surface of the electrode 282 of the surface-emitting laser 280. The cutout portion 203a is provided to shorten the distance between the active layer 281 of the laser 280 and the optical coupler 209. The wiring layer 307 and the electrode 282 are made of, for example, Au (gold). The bonding wire 309 is made of, for example, Au (gold). In this case, the installation location of the laser 280 can be given a degree of freedom.

[0135] For example, as shown in FIG. 38, in the distance measuring device 1100, a through hole 410 is provided that reaches from the bottom surface of the cutout portion 402a of the PIC layer 1200A to the wiring layer 305a in the insulating layer 305 of the lower layer 1300. Furthermore, a bonding wire 411 is provided that is connected to the surface of the wiring layer 305a exposed at the bottom surface of the through hole 410 and the surface of the electrode 282 of the surface-emitting laser 280. The cutout portion 402b is provided to shorten the distance between the active layer 281 of the laser 280 and the optical coupler 209. The wiring layer 305a and the electrode 282 are made of, for example, Au (gold). The bonding wire 411 is made of, for example, Au (gold). In this case, the installation location of the laser 280 can be given a degree of freedom.

[0136] <8. Application Examples> The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, a construction machine, an agricultural machine (tractor), etc.

[0137] Fig. 39 is a block diagram showing a schematic configuration example of a vehicle control system 7000 which is an example of a mobile object control system to which the technology according to the present disclosure can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected via a communication network 7010. In the example shown in Fig. 39, the vehicle control system 7000 includes a drive system control unit 7100, a body system control unit 7200, a battery control unit 7300, an outside-vehicle information detection unit 7400, an inside-vehicle information detection unit 7500, and an integrated control unit 7600. The communication network 7010 connecting these multiple control units may be an in-vehicle communication network conforming to any standard such as CAN (Controller Area Network), LIN (Local Interconnect Network), LAN (Local Area Network), or FlexRay (registered trademark).

[0138] Each control unit includes a microcomputer that performs arithmetic processing according to various programs, a storage unit that stores the programs executed by the microcomputer or parameters used in various calculations, and a drive circuit that drives various control target devices. Each control unit includes a network I / F for communicating with other control units via a communication network 7010, and a communication I / F for communicating with devices or sensors inside and outside the vehicle by wired communication or wireless communication. In FIG. 39, a microcomputer 7610, a general-purpose 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, an audio / video output unit 7670, an in-vehicle network I / F 7680, and a storage unit 7690 are illustrated as functional configurations of the integrated control unit 7600. Other control units also include a microcomputer, a communication I / F, a storage unit, and the like.

[0139] The drivetrain control unit 7100 controls the operation of devices related to the drivetrain of the vehicle according to various programs. For example, the drivetrain control unit 7100 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle. The drivetrain control unit 7100 may also function as a control device such as an ABS (Antilock Brake System) or an ESC (Electronic Stability Control).

[0140] A vehicle state detection unit 7110 is connected to the drive system control unit 7100. The vehicle state detection unit 7110 includes at least one of a gyro sensor that detects the angular velocity of the axial rotational motion of the vehicle body, an acceleration sensor that detects the acceleration of the vehicle, or a sensor for detecting the amount of operation of an accelerator pedal, the amount of operation of a brake pedal, the steering angle of a steering wheel, the engine rotation speed, or the rotation speed of wheels, for example. The drive system control unit 7100 performs arithmetic processing using signals input from the vehicle state detection unit 7110, and controls the internal combustion engine, the drive motor, the electric power steering device, the brake device, etc.

[0141] The body control unit 7200 controls the operation of various devices installed in the vehicle body according to various programs. For example, the body control unit 7200 may be a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as head lamps, back lamps, brake lamps, blinkers, or fog lamps. In this case, radio waves transmitted from a portable device that substitutes for a key or signals from various switches may be input to the body system control unit 7200. The body system control unit 7200 receives these radio waves or signals and controls the door lock device, power window device, lamps, etc. of the vehicle.

[0142] The battery control unit 7300 controls the secondary battery 7310, which is a power supply source for the drive motor, according to various programs. For example, information such as battery temperature, battery output voltage, or remaining capacity of the battery is input to the battery control unit 7300 from a battery device equipped with the secondary battery 7310. The battery control unit 7300 performs calculation processing using these signals, and controls the temperature regulation of the secondary battery 7310 or controls a cooling device or the like equipped in the battery device.

[0143] The outside-vehicle information detection unit 7400 detects information outside the vehicle equipped with the vehicle control system 7000. For example, at least one of an imaging unit 7410 and an outside-vehicle information detection unit 7420 is connected to the outside-vehicle information detection unit 7400. The imaging unit 7410 includes at least one of a ToF (Time Of Flight) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The outside-vehicle information detection unit 7420 includes at least one of an environmental sensor for detecting the current weather or climate, or a surrounding information detection sensor for detecting other vehicles, obstacles, pedestrians, and the like around the vehicle equipped with the vehicle control system 7000.

[0144] The environmental sensor may be, for example, at least one of a raindrop sensor that detects rain, a fog sensor that detects fog, a sunshine sensor that detects the degree of sunshine, and a snow sensor that detects snowfall. The surrounding information detection sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) device. The imaging unit 7410 and the outside vehicle information detection unit 7420 may be provided as independent sensors or devices, or may be provided as a device in which multiple sensors or devices are integrated.

[0145] Here, FIG. 40 shows an example of the installation positions of the imaging unit 7410 and the vehicle exterior information detection unit 7420. The imaging units 7910, 7912, 7914, 7916, and 7918 are provided, for example, at least one of the front nose, side mirrors, rear bumper, back door, and upper part of the windshield in the vehicle interior of the vehicle 7900. The imaging unit 7910 provided on the front nose and the imaging unit 7918 provided on the upper part of the windshield in the vehicle interior mainly acquire images of the front of the vehicle 7900. The imaging units 7912 and 7914 provided on the side mirrors mainly acquire images of the sides of the vehicle 7900. The imaging unit 7916 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 7900. The imaging unit 7918 provided on the upper part of the windshield in the vehicle interior is mainly used to detect a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

[0146] 40 shows an example of the imaging ranges of the imaging units 7910, 7912, 7914, and 7916. Imaging range a indicates the imaging range of the imaging unit 7910 provided on the front nose, imaging ranges b and c indicate the imaging ranges of the imaging units 7912 and 7914 provided on the side mirrors, and imaging range d indicates the imaging range of the imaging unit 7916 provided on the rear bumper or back door. For example, image data captured by the imaging units 7910, 7912, 7914, and 7916 are superimposed to obtain an overhead image of the vehicle 7900.

[0147] The outside information detection units 7920, 7922, 7924, 7926, 7928, and 7930 provided on the front, rear, sides, and corners of the vehicle 7900 and on the upper part of the windshield inside the vehicle cabin may be, for example, ultrasonic sensors or radar devices. The outside information detection units 7920, 7926, and 7930 provided on the front nose, rear bumper, back door, and on the upper part of the windshield inside the vehicle cabin of the vehicle 7900 may be, for example, LIDAR devices. These outside information detection units 7920 to 7930 are mainly used to detect preceding vehicles, pedestrians, obstacles, and the like.

[0148] Returning to FIG. 39, the description will be continued. The outside-vehicle information detection unit 7400 causes the imaging unit 7410 to capture an image outside the vehicle, and receives the captured image data. The outside-vehicle information detection unit 7400 also receives detection information from the outside-vehicle information detection unit 7420 connected thereto. When the outside-vehicle information detection unit 7420 is an ultrasonic sensor, a radar device, or a LIDAR device, the outside-vehicle information detection unit 7400 transmits ultrasonic waves or electromagnetic waves, and receives information on the received reflected waves. The outside-vehicle information detection unit 7400 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, or characters on the road surface, based on the received information. The outside-vehicle information detection unit 7400 may perform environment recognition processing for recognizing rainfall, fog, road surface conditions, and the like, based on the received information. The outside-vehicle information detection unit 7400 may calculate the distance to an object outside the vehicle based on the received information.

[0149] Furthermore, the outside vehicle information detection unit 7400 may perform image recognition processing or distance detection processing to recognize people, cars, obstacles, signs, or characters on the road surface, based on the received image data. The outside vehicle information detection unit 7400 may perform processing such as distortion correction or position adjustment on the received image data, and may generate an overhead image or a panoramic image by synthesizing image data captured by different imaging units 7410. The outside vehicle information detection unit 7400 may perform viewpoint conversion processing using image data captured by different imaging units 7410.

[0150] The in-vehicle information detection unit 7500 detects information inside the vehicle. For example, a driver state detection unit 7510 that detects the state of the driver is connected to the in-vehicle information detection unit 7500. The driver state detection unit 7510 may include a camera that captures an image of the driver, a biosensor that detects the bioinformation of the driver, or a microphone that collects sound in the vehicle cabin. The biosensor is provided, for example, on the seat or steering wheel, and detects the bioinformation of a passenger sitting in the seat or a driver gripping the steering wheel. The in-vehicle information detection unit 7500 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 7510, or may determine whether the driver is dozing. The in-vehicle information detection unit 7500 may perform processing such as noise canceling processing on the collected sound signal.

[0151] The integrated control unit 7600 controls the overall operation of the vehicle control system 7000 according to various programs. The input unit 7800 is connected to the integrated control unit 7600. The input unit 7800 is realized by a device that can be operated by an occupant to input, such as a touch panel, a button, a microphone, a switch, or a lever. Data obtained by voice recognition of a voice input by a microphone may be input to the integrated control unit 7600. The input unit 7800 may be, for example, a remote control device using infrared or other radio waves, or an externally connected device such as a mobile phone or a PDA (Personal Digital Assistant) that supports the operation of the vehicle control system 7000. The input unit 7800 may be, for example, a camera, in which case the occupant can input information by gestures. Alternatively, data obtained by detecting the movement of a wearable device worn by the occupant may be input. Furthermore, the input unit 7800 may include, for example, an input control circuit that generates an input signal based on information input by the occupant using the above-mentioned input unit 7800 and outputs the input signal to the integrated control unit 7600. A passenger or the like operates the input unit 7800 to input various data to the vehicle control system 7000 and to instruct processing operations.

[0152] The storage unit 7690 may include a ROM (Read Only Memory) that stores various programs executed by the microcomputer, and a RAM (Random Access Memory) that stores various parameters, calculation results, sensor values, etc. The storage unit 7690 may be realized by a magnetic storage device such as an HDD (Hard Disc Drive), a semiconductor storage device, an optical storage device, or a magneto-optical storage device, etc.

[0153] The general-purpose communication I / F 7620 is a general-purpose communication I / F that mediates communication between various devices present in the external environment 7750. The general-purpose communication I / F 7620 may implement a cellular communication protocol such as GSM (registered trademark), WiMAX (registered trademark), LTE (registered trademark) (Long Term Evolution) or LTE-Advanced (LTE-A), or other wireless communication protocols such as wireless LAN (also called Wi-Fi (registered trademark)) and Bluetooth (registered trademark). The general-purpose communication I / F 7620 may connect to a device (e.g., an application server or a control server) present on an external network (e.g., the Internet, a cloud network, or a carrier-specific network) via, for example, a base station or an access point. The general-purpose communication I / F 7620 may also connect to a terminal (e.g., a driver's, pedestrian's, or store's terminal, or a Machine Type Communication (MTC) terminal) present in the vicinity of the vehicle using, for example, a Peer To Peer (P2P) technology.

[0154] The dedicated communication I / F 7630 is a communication I / F that supports a communication protocol designed for use in a vehicle. The dedicated communication I / F 7630 may implement a standard protocol such as WAVE (Wireless Access in Vehicle Environment), which is a combination of a lower layer IEEE802.11p and a higher layer IEEE1609, DSRC (Dedicated Short Range Communications), or a cellular communication protocol. The dedicated communication I / F 7630 typically performs V2X communication, which is a concept including one or more of vehicle-to-vehicle communication, vehicle-to-infrastructure communication, vehicle-to-home communication, and vehicle-to-pedestrian communication.

[0155] The positioning unit 7640 performs positioning by receiving, for example, a GNSS signal from a Global Navigation Satellite System (GNSS) satellite (for example, a GPS signal from a Global Positioning System (GPS) satellite) and generates position information including the latitude, longitude, and altitude of the vehicle. The positioning unit 7640 may identify the current position by exchanging signals with a wireless access point, or may obtain position information from a terminal such as a mobile phone, PHS, or smartphone having a positioning function.

[0156] The beacon receiving unit 7650 receives, for example, radio waves or electromagnetic waves transmitted from radio stations or the like installed on the road, and acquires information such as the current location, congestion, road closure, required time, etc. The function of the beacon receiving unit 7650 may be included in the dedicated communication I / F 7630 described above.

[0157] The in-vehicle device I / F 7660 is a communication interface that mediates a connection between the microcomputer 7610 and various in-vehicle devices 7760 present in the vehicle. The in-vehicle device I / F 7660 may establish a wireless connection using a wireless communication protocol such as wireless LAN, Bluetooth (registered trademark), NFC (Near Field Communication), or WUSB (Wireless USB). In addition, the in-vehicle device I / F 7660 may establish a wired connection such as a Universal Serial Bus (USB), a High-Definition Multimedia Interface (HDMI (registered trademark), or a Mobile High-definition Link (MHL)) via a connection terminal (and a cable, if necessary) not shown. The in-vehicle device 7760 may include, for example, at least one of a mobile device or a wearable device owned by a passenger, or an information device carried into or attached to the vehicle. The in-vehicle device 7760 may also include a navigation device that searches for a route to an arbitrary destination. The in-vehicle device I / F 7660 exchanges control signals or data signals with these in-vehicle devices 7760.

[0158] 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 in accordance with a predetermined protocol supported by the communication network 7010.

[0159] The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 according to various programs based on information acquired through at least one of the general-purpose 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 in-vehicle network I / F 7680. For example, the microcomputer 7610 may calculate a control target value of a driving force generating device, a steering mechanism, or a braking device based on the acquired information inside and outside the vehicle, and output a control command to the drive system control unit 7100. For example, the microcomputer 7610 may perform cooperative control for the purpose of realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the distance between vehicles, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc. In addition, the microcomputer 7610 may perform cooperative control for the purpose of autonomous driving, in which the vehicle travels autonomously without relying on driver operation, by controlling a driving force generating device, a steering mechanism, a braking device, etc. based on information acquired about the vehicle's surroundings.

[0160] The microcomputer 7610 may generate three-dimensional distance information between the vehicle and objects such as surrounding structures and people, and create local map information including peripheral information of the current position of the vehicle, based on information acquired via at least one of the general-purpose 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 in-vehicle network I / F 7680. The microcomputer 7610 may also predict dangers such as vehicle collisions, the approach of pedestrians, or entry into a closed road, based on the acquired information, and generate a warning signal. The warning signal may be, for example, a signal for generating a warning sound or turning on a warning lamp.

[0161] The audio / image output unit 7670 transmits at least one of audio and image output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of FIG. 39, an audio speaker 7710, a display unit 7720, and an instrument panel 7730 are illustrated as output devices. The display unit 7720 may include at least one of an on-board display and a head-up display, for example. The display unit 7720 may have an AR (Augmented Reality) display function. The output device may be other devices such as headphones, a wearable device such as a glasses-type display worn by the passenger, a projector, or a lamp, other than these devices. When the output device is a display device, the display device visually displays the results obtained by various processes performed by the microcomputer 7610 or information received from other control units in various formats such as text, image, table, graph, etc. When the output device is an audio output device, the audio output device converts an audio signal consisting of reproduced audio data or acoustic data into an analog signal and audibly outputs it.

[0162] In the example shown in FIG. 39, at least two control units connected via the communication network 7010 may be integrated into one control unit. Alternatively, each control unit may be composed of multiple control units. Furthermore, the vehicle control system 7000 may include another control unit not shown. In the above description, some or all of the functions performed by any control unit may be provided by another control unit. In other words, as long as information is transmitted and received via the communication network 7010, a predetermined arithmetic processing may be performed by any control unit. Similarly, a sensor or device connected to any control unit 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.

[0163] A computer program for realizing each function of the distance measuring device described with reference to Figs. 1 to 38 etc. can be implemented in any control unit etc. Also, a computer-readable recording medium in which such a computer program is stored can be provided. The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory etc. Also, the above computer program may be distributed, for example, via a network, without using a recording medium.

[0164] In the vehicle control system 7000 described above, the distance measuring device described using Figs. 1 to 38 etc. can be used, for example, as a light source steering unit of a LIDAR as an environmental sensor. Also, image recognition in the imaging unit can be performed by an optical computing unit using the distance measuring device described using Figs. 1 to 38 etc. When the distance measuring device described using Figs. 1 to 38 etc. is used as a highly efficient and bright projection device, lines and characters can be projected on the ground. Specifically, lines can be displayed so that people outside the vehicle know where the vehicle will pass when the vehicle is backing up, and a crosswalk can be displayed with light when giving way to pedestrians.

[0165] At least some of the components of the distance measuring device described using Figures 1 to 38 etc. may be realized in a module (for example, an integrated circuit module configured on one die) for integrated control unit 7600 shown in Figure 39. Alternatively, the distance measuring device described using Figures 1 to 38 etc. may be realized by multiple control units of vehicle control system 7000 shown in Figure 39.

[0166] Although the present disclosure has been described above by way of the embodiment and its modified examples, the present disclosure is not limited to the above embodiment and can be modified in various ways. Note that the effects described in this specification are merely examples. The effects of the present disclosure are not limited to the effects described in this specification. The present disclosure may have effects other than those described in this specification.

[0167] Furthermore, for example, the present disclosure can have the following configuration. (1) a PIC (Photonic Integration Circuit) substrate on a common silicon layer, in which a first waveguide for transmitting a chirp signal, a splitter for splitting the chirp signal into a transmission signal and a reference signal, a second waveguide for transmitting a return signal corresponding to a signal whose phase is delayed relative to the transmission signal, and a signal generating unit for generating a beat signal based on the reference signal and the return signal are all formed; a signal processing board on which a converter that performs AD conversion of the beat signal and a signal processing unit that processes the digital beat signal generated by the converter are formed; Equipped with The PIC substrate and the signal processing substrate are stacked on top of each other and are electrically connected to each other via their joint surfaces. Ranging device. (2) A modulator for generating the chirp signal and a Si antenna for emitting the transmission signal to the outside and receiving the return signal from the outside are formed on the Si layer. A distance measuring device as described in (1). (3) A light source chip mounted on the PIC board for generating an optical signal is further provided. a control unit that controls the light source chip, the modulator, and the Si antenna is formed on the signal processing board; The light source chip generates the optical signal under the control of the control unit; The modulator generates the chirp signal by modulating the optical signal under the control of the control unit; The Si antenna sweeps the transmission signal in a predetermined external area under the control of the control unit. A distance measuring device according to one or more of (1) to (2). (4) The PIC substrate and the signal processing substrate are electrically connected to each other by bonding copper pads provided on the bonding surfaces of the PIC substrate and the signal processing substrate to each other. A distance measuring device according to one or more of (1) to (3). (5) The PIC substrate and the signal processing substrate are electrically connected to each other via through-holes that penetrate the bonding surfaces of the PIC substrate and the signal processing substrate. A ranging device according to one or more of (1) to (4). (6) The signal processing board is in the form of a chip smaller than the PIC board and is mounted on the surface of the PIC board. A ranging device according to one or more of (1) to (5). (7) the signal processing board further comprises a first marker; The PIC substrate further includes a second marker at a position opposite to the first marker. A ranging device according to one or more of (1) to (6). (8) the light source chip is an edge-emitting laser and is mounted on the PIC substrate such that a light spot of the light source chip is at the same height as the Si layer; The light source chip inputs the optical signal to a modulator through an end face of the first waveguide. A distance measuring device according to one or more of (1) to (7). (9) The light source chip and the PIC substrate are electrically connected to each other by bonding copper pads provided between the light source chip and the PIC substrate. A distance measuring device according to one or more of (1) to (8). (10) The light source chip and the PIC substrate are electrically connected to each other via metal bumps provided between the light source chip and the PIC substrate. A distance measuring device according to one or more of (1) to (9). (11) The PIC substrate is provided with a tapered waveguide having an end face continuous with an end face of the first waveguide. A distance measuring device according to one or more of (1) to (10). (12) the light source chip is a laser that emits the optical signal in a stacking direction, An optical coupler for optically coupling the light source chip and the first waveguide is formed in the Si layer. A distance measuring device according to one or more of (1) to (11). (13) the light source chip is a laser that emits the optical signal in a stacking direction, In the PIC substrate, an optical element that refracts the optical signal is formed between the light source chip and the Si layer, and an optical coupler that optically couples the light source chip and the first waveguide via the optical element is formed in the Si layer. A distance measuring device according to one or more of (1) to (12). (14) the light source chip is a laser that emits the optical signal in a direction that obliquely intersects with a lamination direction, An optical coupler for optically coupling the light source chip and the first waveguide is formed in the Si layer. A distance measuring device according to one or more of (1) to (13). (15) A gap is provided in the PIC substrate at a location where the Si antenna is in contact with the PIC substrate. A distance measuring device according to one or more of (1) to (14). (16) the PIC substrate has a first insulating layer and a second insulating layer sandwiching the Si layer; The void is formed in at least one of the first insulating layer and the second insulating layer. A distance measuring device according to one or more of (1) to (15). (17) A reflection layer that reflects the return signal and causes the reflected light to enter the Si antenna is formed in a portion of the PIC substrate that faces the Si antenna. A distance measuring device according to one or more of (1) to (16). (18) a first optical waveguide capable of transmitting a chirp signal; a splitter capable of splitting the chirp signal into a transmission signal and a reference signal; a coupler detector block capable of outputting a beat signal based on the reference signal and the return signal; A first substrate having a converter capable of outputting a digital beat signal based on the beat signal; a controller capable of outputting an electronic control signal for controlling generation of the chirp signal; A second substrate having the above structure and laminated on the first substrate. A distance measuring device comprising: (19) The first substrate is a light source mounted on the first substrate for generating light for modulation by a modulator to generate the chirp signal; an antenna for transmitting said chirp signal and receiving said return signal; The distance measuring device according to (18) further comprising: (20) The coupler detector block includes: an optical coupler that combines the reference signal and the return signal; at least one detector that detects the output of the optical coupler and outputs the beat signal; A distance measuring device according to any one or more of (18) to (19) above, comprising: (twenty one) The first and second substrates have one or more wiring layers that electrically connect the coupler detector block to the converter. A distance measuring device according to one or more of (18) to (20). (twenty two) The one or more wiring layers have a first plurality of pads of the first substrate bonded to a second plurality of pads of the second substrate. A distance measuring device according to one or more of (18) to (21). (twenty three) The one or more wiring layers have one or more through-hole vias that join the first substrate to the second substrate. A distance measuring device according to one or more of (18) to (22). (twenty four) The light source includes a vertical cavity surface emitting laser disposed above an optical coupler on the first substrate. A distance measuring device according to one or more of (18) to (23). (twenty five) The one or more through-hole vias include a through-hole via that penetrates the first substrate. A distance measuring device according to one or more of (18) to (24). (26) The footprint of the second substrate is smaller than the footprint of the first substrate. A distance measuring device according to one or more of (18) to (25). (27) The second substrate further includes an STI portion below the antenna. A distance measuring device according to one or more of (18) to (26). (28) The first substrate further includes an air gap above or below the antenna. A distance measuring device according to one or more of (18) to (27). (29) The first substrate further includes an air gap above and below the antenna. A distance measuring device according to one or more of (18) to (28). (30) At least one of the first substrate or the second substrate has a reflective layer below the antenna. A distance measuring device according to one or more of (18) to (29). (31) The light source is electrically connected to the second substrate by a bonding wire. A distance measuring device according to one or more of (18) to (30). (32) a tapered optical waveguide portion located at an end of the first optical waveguide that receives the chirp signal. A distance measuring device according to one or more of (18) to (31). (33) a first substrate having one or more optical circuits for transmitting a transmission signal to a target and receiving a return signal from the target; a second substrate bonded to the first substrate and having one or more electronic circuits for controlling generation of the transmit signal and processing the return signal; A distance measuring device comprising: (34) The one or more optical circuits include one or more optical waveguides; a splitter for splitting the chirp signal from the light source into a reference signal and a transmission signal; an antenna for transmitting the transmission signal and receiving the return signal; a coupler for combining the reference signal and the return signal; a detector that detects the output of the coupler and outputs a beat signal; The distance measuring device according to (33) above, (35) The one or more electronic circuits include a digital-to-analog converter (DAC) for driving the light source; an analog-to-digital converter (ADC) that receives the beat signal from the detector; a controller connected to the DAC and the ADC; A distance measuring device according to any one or more of (34) to (35) above, comprising: (36) The first and second substrates each have one or more wiring layers that electrically connect the DAC to the light source and electrically connect the detector to the ADC. A distance measuring device according to one or more of (33) to (35). (37) Target and A range finder for measuring the distance to the target; The distance measuring device comprises: a first optical waveguide capable of transmitting a chirp signal; a splitter capable of splitting the chirp signal into a transmission signal and a reference signal; a coupler detector block capable of outputting a beat signal based on the reference signal and the return signal; A first substrate having a converter capable of outputting a digital beat signal based on the beat signal; a controller capable of outputting an electronic control signal for controlling generation of the chirp signal; A second substrate laminated on the first substrate. A system equipped with

[0168] In a distance measuring device according to one aspect of the present disclosure, a first waveguide, a splitter, a second waveguide, and a signal generating unit are formed in a common Si layer in a PIC substrate. A converter and a signal processing unit are formed in a signal processing substrate. The PIC substrate and the signal processing substrate are stacked on top of each other and are electrically connected to each other via the joint surfaces of the PIC substrate and the signal processing substrate. This allows for a smaller size than a module in which multiple RF components are coupled via optical fibers.

[0169] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur to those skilled in the art depending on design requirements and other factors, and that such modifications are within the scope of the appended claims and their equivalents. [Explanation of symbols]

[0170] 71...Si terrace portion, 72...p-type Si layer, 73...island-shaped i-type Ge layer, 74...two-dimensionally grown i-type Ge layer, 75...n-type Ge layer, 76...n-side electrode, 77...p-side electrode, 100,500,600,1100...range finder, 110...SOI substrate, 111...Si substrate, 111a...opening, 200,400...upper die, 200A,400A,700A...PIC substrate, 201...Si layer, 202...interlayer insulating film, 203...BOX layer, 204,207...connection pad, 204a...reflective layer, 205...lens, 206...notch portion, 208...optical waveguide portion, 209... Optical coupler, 210... laser, 211... active layer, 212... bump, 213... solder, 215... Cu electrode, 220... modulator, 230... splitter, 240... circulator, 250... antenna, 251... Si antenna, 252... heater, 253, 254, 255... optical switch, 258... gap, 257... wall, 260... coupler, 261, 262... optical waveguide, 270... detector, 271, 272... GePD, 273... transimpedance amplifier, 280... laser, 281... active layer, 290... prism, 300, 700... bottom Part die, 301...Si substrate, 302...interlayer insulating film, 303...connection pad, 304...marker, 305...insulating layer, 306...light shielding layer, 310...controller, 320...DAC, 330...ADC, 340...FFT, 401...insulating layer, 402...interlayer insulating film, 403, 407...through hole via, 404...wiring layer, 405, 409...light shielding portion, 406...notch portion, 408...connection pad, 701...notch portion, 702...connection pad, 703...marker, 704...wiring layer, 705...GePD, 706...gap, 707, 708...wall portion, 709...groove part, 710...module lens, 720...Si substrate, 800...upper chip, 900...module lens, 910...Si substrate, 1200...upper layer, 1200A...PIC layer, 1210, 1230...via, 1220...wiring layer, 1240...STI part, 1300...lower layer, 2100, 2200...resist layer, 2110, 2210...opening, S1...bonding surface, S2...input / output surface, S3, S4...surface, Sbt...beat signal, Stx, Stx1, Stx2...transmitted signal, Srx...received signal, TG...target, WG1, WG2, WG3...optical waveguide.

Claims

1. a first optical waveguide capable of transmitting a chirp signal; a splitter capable of splitting the chirp signal into a transmission signal and a reference signal; a coupler detector block capable of outputting a beat signal based on the reference signal and the return signal; A first substrate having a converter capable of outputting a digital beat signal based on the beat signal; a controller capable of outputting an electronic control signal for controlling generation of the chirp signal; A second substrate having the above structure and laminated on the first substrate. A distance measuring device comprising:

2. The first substrate is a light source mounted on the first substrate for generating light for modulation by a modulator to generate the chirp signal; an antenna for transmitting said chirp signal and receiving said return signal; The distance measuring device according to claim 1 , further comprising:

3. The coupler detector block includes: an optical coupler that combines the reference signal and the return signal; at least one detector that detects the output of the optical coupler and outputs the beat signal; 2. The distance measuring device according to claim 1, comprising:

4. The first and second substrates have one or more wiring layers that electrically connect the coupler detector block to the converter.

2. A distance measuring device according to claim 1.

5. The one or more wiring layers include a first plurality of pads of the first substrate bonded to a second plurality of pads of the second substrate.

5. A distance measuring device according to claim 4.

6. The one or more wiring layers have one or more through-hole vias that join the first substrate to the second substrate.

5. A distance measuring device according to claim 4.

7. The light source includes a vertical cavity surface emitting laser disposed above an optical coupler on the first substrate.

3. A distance measuring device according to claim 2.

8. The one or more through-hole vias include a through-hole via that penetrates the first substrate.

7. A distance measuring device according to claim 6.

9. The footprint of the second substrate is smaller than the footprint of the first substrate.

5. A distance measuring device according to claim 4.

10. The second substrate further includes an STI portion below the antenna.

3. A distance measuring device according to claim 2.

11. The first substrate further includes an air gap above or below the antenna.

3. A distance measuring device according to claim 2.

12. The first substrate further includes an air gap above and below the antenna.

3. A distance measuring device according to claim 2.

13. At least one of the first substrate or the second substrate has a reflective layer below the antenna.

3. A distance measuring device according to claim 2.

14. The light source is electrically connected to the second substrate by a bonding wire.

3. A distance measuring device according to claim 2.

15. a tapered optical waveguide portion located at an end of the first optical waveguide for receiving the chirp signal.

2. A distance measuring device according to claim 1.

16. a first substrate having one or more optical circuits for transmitting a transmission signal to a target and receiving a return signal from the target; a second substrate bonded to the first substrate and having one or more electronic circuits for controlling generation of the transmit signal and processing the return signal; A distance measuring device comprising:

17. The one or more optical circuits include one or more optical waveguides; a splitter for splitting the chirp signal from the light source into a reference signal and a transmission signal; an antenna for transmitting the transmission signal and receiving the return signal; a coupler for combining the reference signal and the return signal; a detector that detects the output of the coupler and outputs a beat signal; 17. The distance measuring device according to claim 16, comprising:

18. The one or more electronic circuits include a digital-to-analog converter (DAC) for driving the light source; an analog-to-digital converter (ADC) that receives the beat signal from the detector; a controller coupled to the DAC and the ADC; 18. The distance measuring device according to claim 17, comprising:

19. The first and second substrates each have one or more wiring layers that electrically connect the DAC to the light source and electrically connect the detector to the ADC.

20. A distance measuring device according to claim 18.

20. Target, A range finder for measuring the distance to the target; The distance measuring device comprises: a first optical waveguide capable of transmitting a chirp signal; a splitter capable of splitting the chirp signal into a transmission signal and a reference signal; a coupler detector block capable of outputting a beat signal based on the reference signal and the return signal; A first substrate having a converter capable of outputting a digital beat signal based on the beat signal; a controller capable of outputting an electronic control signal for controlling generation of the chirp signal; A second substrate having the above structure and laminated on the first substrate. A system equipped with

Images