Optoelectronic integrated structure and method of manufacturing thereof

Abstract

The application provides an optoelectronic integrated structure and a manufacturing method thereof, comprising a driving structure, a switching structure and a laser structure. The driving structure and the switching structure comprise a first substrate, a first gallium nitride layer, an interlayer medium and a first insulating layer which are sequentially stacked, the driving structure comprises a driving transistor, and the switching structure comprises a switching transistor. The laser structure comprises a gallium arsenide layer, a diode structure and a first electrode layer which are sequentially stacked, a first lead-out structure is electrically connected with the gallium arsenide layer or the first electrode layer, the first lead-out structure and a first connecting structure are in direct contact, the first connecting structure is in direct contact with a source electrode of the switching transistor or a drain electrode of the switching transistor, and the first connecting structure comprises a first metal layer of a substrate or a metal bonding layer when the switching structure and the laser structure are connected. The application integrates the driving structure, the switching structure and the laser structure, shortens the transmission distance of an electric signal, reduces parasitic inductance, reduces loss, and improves detection accuracy.

Description

Technical Field

[0001] This invention relates to the field of semiconductors, and in particular to an optoelectronic integrated structure and its manufacturing method. Background Technology

[0002] Optical detection and ranging (LiDAR) is a technology that uses optical ranging to achieve long-range distance detection. Optical detection and ranging can be implemented using lidar systems. The main principle of lidar is to emit pulsed laser light from a laser source onto a target object and receive the reflection signal from the target object. By calculating the time difference between the emitted laser pulse and the received reflection signal, the relative distance between the target object and the laser source can be measured.

[0003] The range of a lidar system is related to its peak pulse power; the higher the pulse power, the farther the detection range. Simultaneously, the lidar's frequency division is related to its shortest pulse width; the narrower the pulse width, the higher the resolution. Therefore, to achieve long-range detection, a lidar system needs to possess both high peak power and a short pulse width.

[0004] A lidar system consists of a driving structure, a switching structure, and a laser structure, which are electrically connected through a printed circuit board (PCB). This means that the driving structure, switching structure, and laser structure can only transmit electrical signals through the metal lines on the PCB. The long distance of the electrical signal transmission results in a large parasitic inductance in the lidar system, which in turn increases the loss of the lidar system and reduces the detection accuracy. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide an optoelectronic integrated structure and its manufacturing method, which can reduce parasitic inductance, reduce losses, and improve detection accuracy.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] This application provides an optoelectronic integrated structure, which includes: a driving structure, a switching structure, and a laser structure;

[0008] The driving structure and the switching structure include a first substrate, a first gallium nitride layer, an interlayer dielectric, and a first insulating layer stacked sequentially; the driving structure includes a driving transistor, and the switching structure includes a switching transistor, wherein the source of the driving transistor, the source of the switching transistor, and the drain of the switching transistor penetrate at least through the interlayer dielectric and a portion of the thickness of the first insulating layer, and the source of the driving transistor and the source of the switching transistor are electrically connected.

[0009] The laser structure includes a gallium arsenide layer, a diode structure, and a first electrode layer stacked sequentially.

[0010] The first lead-out structure is electrically connected to the gallium arsenide layer or the first electrode layer, the first lead-out structure is in direct contact with the first connection structure, and the first connection structure is in direct contact with the source or drain of the switching transistor.

[0011] The first connection structure includes a first metal layer disposed on the substrate or a metal bonding layer when the switch structure and the laser structure are connected; the substrate is used to place the driving structure, the switch structure and the laser structure.

[0012] Optionally, the laser structure includes a second insulating layer, which is at least disposed on the side of the gallium arsenide layer away from the laser emission direction of the laser structure, wherein the laser emission direction of the laser structure is along one side of the gallium arsenide layer;

[0013] The first lead-out structure is disposed in the second insulating layer, and the second insulating layer is in contact with the first insulating layer. The first connection structure is disposed in the second insulating layer and the first insulating layer. The first lead-out structure is electrically connected to the gallium arsenide layer, and the first connection structure is in direct contact with the drain of the switching transistor.

[0014] Optionally, the input voltage layer of the laser structure is disposed on the first insulating layer;

[0015] The first electrode layer and the second connection structure are in direct contact, and the second connection structure is in direct contact with the input voltage layer of the laser structure; the second connection structure is the metal bonding layer when the switch structure and the laser structure are connected.

[0016] Optionally, the substrate further includes a second metal layer, and the first insulating layer further includes a first groove that exposes the input voltage layer of the laser structure. The second metal layer and the input voltage layer of the laser structure are electrically connected by wire bonding.

[0017] Optionally, the input voltage layer of the laser structure penetrates the interlayer medium, the first gallium nitride layer, and a portion of the thickness of the first substrate;

[0018] An isolation structure is disposed on the first gallium nitride layer and the first substrate to isolate the input voltage layer of the switching structure and the laser structure.

[0019] Optionally, the substrate is a printed circuit board or a silicon interposer, the laser structure and the switch structure are disposed on both sides of the printed circuit board or the silicon interposer, and the first metal layer penetrates the printed circuit board or the silicon interposer.

[0020] Optionally, the substrate is a printed circuit board or a silicon interposer, the laser structure, the switch structure and the driving structure are disposed on the same side of the printed circuit board or the silicon interposer, and the first metal layer is disposed on one side surface of the printed circuit board or the silicon interposer.

[0021] Optionally, the laser structure, the switch structure, and the driving structure are disposed on the same side of the substrate, the interlayer dielectric is disposed on the surface of the first insulating layer away from the substrate, and the gallium arsenide layer is disposed on the surface of the diode structure close to the substrate.

[0022] The first lead-out structure is electrically connected to the first electrode layer, and the first connection structure is in direct contact with the source of the switching transistor.

[0023] Optionally, the first connection structure includes a first metal layer disposed on the substrate, and the first lead-out structure includes a wire bonding or through-hole contact connecting the first metal layer and the first electrode layer.

[0024] Optionally, the gallium arsenide layer is disposed on the side of the diode structure near the substrate; the first lead-out structure and the gallium arsenide layer are electrically connected;

[0025] The first connection structure includes a metal layer under the bump, which is in direct contact with the drain of the switching transistor.

[0026] Optionally, the laser emission direction of the laser structure is along one side surface of the gallium arsenide layer, one side surface of the first electrode layer, or along the sidewall of the diode structure.

[0027] This application provides a method for manufacturing an optoelectronic integrated structure, including:

[0028] A driving structure, a switching structure, and a laser structure are obtained. The driving structure and the switching structure include a first substrate, a first gallium nitride layer, an interlayer dielectric, and a first insulating layer stacked sequentially. The driving structure includes a driving transistor, and the switching structure includes a switching transistor. The source of the driving transistor, the source of the switching transistor, and the drain of the switching transistor penetrate at least through the interlayer dielectric and a portion of the thickness of the first insulating layer. The source of the driving transistor and the source of the switching transistor are electrically connected. The laser structure includes a gallium arsenide layer, a diode structure, and a first electrode layer stacked sequentially.

[0029] The first insulating layer is etched to form a plurality of openings, the plurality of openings exposing at least the drain or source of the switching transistor;

[0030] The opening is filled with metal to form a metal bonding layer;

[0031] The first lead structure is electrically connected to the gallium arsenide layer or the first electrode layer, the first lead structure and the first connection structure are in direct contact, and the first connection structure is in direct contact with the source or the drain of the switching transistor.

[0032] The first connection structure includes a first metal layer disposed on the substrate or a metal bonding layer when the switch structure and the laser structure are connected; the substrate is used to place the driving structure, the switch structure and the laser structure.

[0033] This application provides an optoelectronic integrated structure, comprising a driving structure, a switching structure, and a laser structure. The driving structure and the switching structure each include a first substrate, a first gallium nitride layer, an interlayer dielectric, and a first insulating layer, sequentially stacked. The driving structure includes a driving transistor, and the switching structure includes a switching transistor. The source of the driving transistor, the source of the switching transistor, and the drain of the switching transistor all penetrate at least the interlayer dielectric and a portion of the thickness of the first insulating layer. The source of the driving transistor and the source of the switching transistor are electrically connected. In other words, the driving structure and the switching structure are integrated into one unit, sharing the same film layer. Therefore, when the driving structure and the switching structure are electrically connected, the source of the driving transistor and the source of the switching transistor can be directly connected on the same film layer, eliminating the need for metal traces on a PCB, thereby reducing the parasitic inductance between the driving structure and the switching structure.

[0034] The laser structure includes a gallium arsenide layer, a diode structure, and a first electrode layer stacked sequentially. A first lead-out structure is electrically connected to the gallium arsenide layer or the first electrode layer. The first lead-out structure is in direct contact with a first connection structure, and the first connection structure is in direct contact with the source or drain of a switching transistor. The first connection structure includes a first metal layer disposed on a substrate or a metal bonding layer for connecting the switching structure and the laser structure. The substrate is used to house the driving structure, the switching structure, and the laser structure. In other words, the laser structure and the switching structure are integrated into one unit, electrically connected through the first lead-out structure and the first connection structure, significantly shortening the electrical signal transmission distance and thus reducing the parasitic inductance between the switching structure and the laser structure.

[0035] As can be seen, this application integrates the driving structure, switching structure and laser structure into one unit, eliminating the need to separately package the driving structure, switching structure and laser structure into discrete devices and then connect these discrete devices using metal lines on the PCB board. This shortens the electrical signal transmission distance, reduces parasitic inductance, reduces losses, and improves detection accuracy. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 A circuit diagram of a lidar system is shown;

[0038] Figure 2 This paper shows a cross-sectional schematic diagram of an optoelectronic integrated structure provided in an embodiment of this application;

[0039] Figure 3 A circuit diagram of an optoelectronic integrated structure provided in an embodiment of this application is shown;

[0040] Figure 4 This paper shows a top view of an optoelectronic integrated structure provided in an embodiment of the present application.

[0041] Figures 5-10 This application provides cross-sectional schematic diagrams of various optoelectronic integrated structures according to embodiments;

[0042] Figure 11 A circuit diagram of another optoelectronic integrated structure provided in an embodiment of this application is shown;

[0043] Figures 12-13 This application provides cross-sectional schematic diagrams of various optoelectronic integrated structures according to embodiments;

[0044] Figure 14 A schematic flowchart of a method for manufacturing an optoelectronic integrated structure according to an embodiment of this application is shown;

[0045] Figures 15-17 A schematic diagram of the structure of the optoelectronic integrated structure manufactured according to the manufacturing method of the optoelectronic integrated structure provided in the embodiments of this application is shown. Detailed Implementation

[0046] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0047] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0048] This application is described in detail with reference to the schematic diagrams. When detailing the embodiments of this application, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this application. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0049] A lidar system consists of a driving structure, a switching structure, and a laser structure. These three structures are independently packaged as discrete components and soldered onto a printed circuit board (PCB). They are electrically connected through metal lines on the PCB. In other words, the driving structure, switching structure, and laser structure can only transmit electrical signals through the metal lines on the PCB. Because the three structures are independently packaged discrete components, the electrical signal transmission distance is relatively long, resulting in a large parasitic inductance in the lidar system. This increases the loss of the lidar system and reduces its detection accuracy.

[0050] In other words, discrete devices introduce parasitic inductance due to their packaging or long electrical propagation distances. (Reference) Figure 1 As shown, Figure 1 A circuit connection diagram of the drive structure (Drv), switch structure, and laser structure (Laser) is shown. The switch structure is a Si-based metal-oxide-semiconductor (Si MOS) device. Parasitic inductances include the following types: (1) Parasitic inductance L between the output port of the drive structure and the gate of the switch structure. G This will reduce the rise and fall speeds, thereby increasing the minimum pulse width and resolution. At the same time, due to the slow rise and fall, the losses during the switching process will also increase, and the heat generation will increase. When the input pulse width is not long enough, the pulse current cannot reach the peak current in time, resulting in a decrease in the output peak optical power and a limited detection distance. (2) There is a parasitic common-source inductance L between the ground potential of the driving structure and the source of the switching structure. CSI Its presence not only generates a reverse gate-source voltage difference when the switching structure is turned on, hindering the speed of the switching structure's turn-on, but also generates a large forward gate-source voltage difference when the switching structure is turned off rapidly, i.e., under a large current change with time (di / dt), causing the switching structure to mis-turn on. (3) There is a parasitic inductance L between the switching structure and the laser structure. LD This parasitic inductance is mainly introduced by wire bonding during the laser structure packaging. This parasitic inductance slows down the pulse on / off speed, thus affecting detection accuracy. At the same time, prolonged voltage and current overlap also increases losses.

[0051] Furthermore, when the switching device is a Si MOS, the switching figure of merit (FoM) is larger, the driving charge is larger and the switching speed is slower at the same peak current.

[0052] Based on this, this application provides an optoelectronic integrated structure, which includes a driving structure, a switching structure, and a laser structure. The driving structure and the switching structure each include a first substrate, a first gallium nitride layer, an interlayer dielectric, and a first insulating layer stacked sequentially. The driving structure includes a driving transistor, and the switching structure includes a switching transistor. The source of the driving transistor, the source of the switching transistor, and the drain of the switching transistor penetrate at least through the interlayer dielectric and a portion of the thickness of the first insulating layer. The source of the driving transistor and the source of the switching transistor are electrically connected. The laser structure includes a gallium arsenide layer, a diode structure, and a first electrode layer stacked sequentially. A first lead-out structure is electrically connected to the gallium arsenide layer or the first electrode layer. The first lead-out structure is in direct contact with a first connection structure, and the first connection structure is in direct contact with the source of the switching transistor or the drain of the switching transistor. The first connection structure includes a first metal layer disposed on the substrate or a metal bonding layer for connecting the switching structure and the laser structure. The substrate is used to house the driving structure, the switching structure, and the laser structure. As can be seen, this application integrates the driving structure, switching structure and laser structure into one unit, eliminating the need to separately package the driving structure, switching structure and laser structure into discrete devices and then connect these discrete devices using metal lines on the PCB board. This shortens the electrical signal transmission distance, reduces parasitic inductance, reduces losses, and improves detection accuracy.

[0053] To better understand the technical solution and effects of this application, the specific embodiments will be described in detail below with reference to the accompanying drawings.

[0054] refer to Figure 2 The diagram shown is a cross-sectional view of an optoelectronic integrated structure provided in an embodiment of this application. The optoelectronic integrated structure provided in this embodiment includes: a driving structure 100, a switching structure 200, and a laser structure 300.

[0055] In the embodiments of this application, the driving structure 100, the switching structure 200, and the laser structure 300 constitute a lidar system. A circuit diagram of the lidar system is shown below. Figure 3 As shown, the gate drive circuit is the circuit of drive structure 100. The simplest gate drive circuit includes four drive transistors 150, represented by D1, E1, E2, and E3, where D represents a depletion-type transistor and E represents an enhancement-type transistor. The power device E4 is the circuit of switch structure 200, and the diode connected to the input signal Vin is the circuit of laser structure 300. (Reference) Figure 4 The diagram shown is a top view of the drive structure 100, the switch structure 200, and the laser structure 300. Figure 2 For along Figure 4 A schematic diagram of the cross-sectional structure obtained by performing a cross-section along the N-N direction. Figure 4The vertical cavity surface emitting laser (VCSEL) is laser structure 300, where A represents the anode of laser structure 300 and C represents the cathode of laser structure 300.

[0056] In embodiments of this application, the driving structure 100 and the switching structure 200 include a first substrate 110, a first gallium nitride layer 120, an interlayer dielectric 130, and a first insulating layer 140 sequentially stacked. The first substrate 110 can be a semiconductor material, such as silicon, sapphire, or silicon carbide. The interlayer dielectric 130 can be an insulating material, for example, silicon oxide formed using a vapor deposition process. The interlayer dielectric 130 may include a first interlayer dielectric 131 and a second interlayer dielectric 132, the second interlayer dielectric 132 being disposed on the surface of the first interlayer dielectric 131 away from the first substrate 110, as shown in the reference. Figure 2 As shown. The first gallium nitride layer 120 can be a stacked structure. For example, the first gallium nitride layer 120 may include an AlN nucleation layer, an AlGaN / GaN stress buffer layer, a carbon-doped high-resistivity GaN buffer layer, and a GaN channel layer stacked sequentially.

[0057] The driving structure 100 includes multiple driving transistors 150, which constitute a gate driving circuit. Each driving transistor 150 includes a source, a drain, and a gate, where the source is represented by S, the drain by D, and the gate by G. The driving transistors 150 are mainly disposed in the interlayer dielectric 130. The source and drain of the driving transistors 150 are in direct contact with the first gallium nitride layer 120. An additional film layer, such as an aluminum gallium nitride layer 160, can be disposed between the gate of the driving transistor 150 and the first gallium nitride layer 120. Figure 2 As shown, another example is the P-type gallium nitride layer 170, reference... Figure 5 As shown, there are also aluminum gallium nitride layer 160 and p-type gallium nitride layer 170, reference Figure 2 As shown. The aluminum gallium nitride layer 160 can also be called an aluminum gallium nitride barrier layer.

[0058] As an example, Figure 2 The driving structure 110 illustrates two driving transistors 150, D1 and E1. The source of D1 and the drain of E1 are electrically connected in the interlayer dielectric 130. The source of D1 penetrates the interlayer dielectric 130 to achieve the driving supply voltage (V). DD Layer 180 is electrically connected, E1's gate and drive input signal (V) PWM )Layer 190 electrical connection ( Figure 2 (Not shown).

[0059] The switching structure 200 includes a switching transistor 210, which includes a source, a drain, and a gate. The source is denoted by S, the drain by D, and the gate by G. The switching transistor 210 is primarily disposed in the interlayer dielectric 130. The source and drain of the switching transistor 210 are in direct contact with the first gallium nitride layer 120. An additional film layer, such as a P-type gallium nitride layer 170, can be disposed between the gate of the switching transistor 210 and the first gallium nitride layer 120. (See reference...) Figure 5 As shown, for example, aluminum gallium nitride layer 160 and p-type gallium nitride layer 170, see reference. Figure 2 As shown.

[0060] The source of the driving transistor 150, the source of the switching transistor 210, and the drain of the switching transistor 210 penetrate at least through the interlayer dielectric 130 and a portion of the thickness of the first insulating layer 140, and the source of the driving transistor 150 and the source of the switching transistor 210 are electrically connected.

[0061] As an example, the sources of E1 and E4 penetrate at least through the interlayer dielectric 130 and a portion of the thickness of the first insulating layer 140, and are in direct contact with the first insulating layer 140. Considering that the sources of E1 and E4 need to be grounded, the sources of E1 and E4 can be in direct contact with the gallium nitride via (TGV) layer 220, which penetrates at least through the interlayer dielectric 130 and the first gallium nitride layer 120 to the first substrate 110, thereby achieving grounding.

[0062] In other words, the driving structure 100 and the switching structure 200 are integrated into one unit, sharing the same film layer. Therefore, when the driving structure 100 and the switching structure 200 are electrically connected, the source of the driving transistor 150 and the source of the switching transistor 210 can be directly connected on the same film layer. Since the driving structure 100 and the switching structure 200 do not need to be separately packaged to form discrete devices, nor do they need to utilize metal traces on the PCB for electrical connection, the parasitic inductance between the driving structure 100 and the switching structure 200 is reduced; specifically, the parasitic inductance L between the output port of the driving structure 100 and the gate of the switching structure 200 is reduced. G and the parasitic common-source inductance L between the ground potential of the drive structure 100 and the source of the switch structure 200. CSI Both will decrease.

[0063] In the embodiments of this application, the laser structure 300 includes a gallium arsenide layer 310, a diode structure 320, and a first electrode layer 330 stacked sequentially. The structure electrically connected to the gallium arsenide layer 310 can serve as the cathode of the laser structure 300. For example, if the first lead-out structure 410 is in contact with the gallium arsenide layer 310, then the first lead-out structure 410 can serve as the cathode of the laser structure 300. The first electrode layer 330 can serve as the anode of the laser structure 300. The diode structure 320 is formed by stacking multiple film layers and can perform photoelectric conversion to form laser light, thereby enabling laser emission from the laser structure 300.

[0064] To achieve electrical connection between the laser structure 300 and the switch structure 200, electrical signal transmission between them can be achieved through the first lead-out structure 410 and the first connection structure 420. The first lead-out structure 410 and the first connection structure 420 can be made of materials with good conductivity, such as metals. The first lead-out structure 410 is electrically connected to the gallium arsenide layer 310 or the first electrode layer 330, that is, the first lead-out structure 410 is electrically connected to the cathode or anode of the laser structure 300. The first lead-out structure 410 and the first connection structure 420 are in direct contact, and the first connection structure 420 is in direct contact with the source or drain of the switch transistor 210. In other words, the gallium arsenide layer 310 and the drain of the switch transistor 210 can be electrically connected through the first lead-out structure 410 and the first connection structure 420, thereby achieving... Figure 3 and Figure 4 The circuit connection in the circuit. The source of the first electrode layer 330 and the switching transistor 210 can also be electrically connected through the first lead structure 410 and the first connection structure 420, thereby realizing... Figure 11 The circuit connection is shown.

[0065] Specifically, the first connection structure 420 may include a first metal layer 510 disposed on a substrate 500, the substrate 500 being used to place the driving structure 100, the switch structure 200 and the laser structure 300, or the first connection structure 420 may include a metal bonding layer for the connection of the switch structure 200 and the laser structure 300, wherein the connection of the switch structure 200 and the laser structure 300 may be achieved by bonding or welding.

[0066] In other words, the laser structure 300 and the switch structure 200 can also be integrated into one unit, and electrical connection is achieved through the first lead-out structure 410 and the first connection structure 420, which greatly shortens the electrical signal transmission distance and reduces the parasitic inductance between the switch structure 200 and the laser structure 300.

[0067] As can be seen, this application integrates the driving structure, switching structure and laser structure into one unit, eliminating the need to separately package the driving structure, switching structure and laser structure into discrete devices and then connect these discrete devices using metal lines on the PCB board. This shortens the electrical signal transmission distance, reduces parasitic inductance, reduces losses, and improves detection accuracy.

[0068] Considering that the laser emission direction and circuit connection of the laser structure 300 may differ, the specific configuration of the first lead-out structure 410 and the first connection structure 420 may also differ. The details are as follows:

[0069] In the first scenario, the laser emission direction of the laser structure 300 is along one side of the gallium arsenide layer 310. In this case, the structure of the laser structure 300 along the laser emission direction is, in sequence, a first electrode layer 330, a diode structure 320, and the gallium arsenide layer 310, i.e., the laser structure 300 is placed upside down. In this case, the driving structure 100 and the switching structure 200 are placed upright, i.e., along the laser emission direction, they are, in sequence, a first substrate 110, a first gallium nitride layer 120, an interlayer dielectric 130, and a first insulating layer 140. Considering the placement stability of the upside-down laser structure 300, the laser structure 300 includes a second insulating layer 340. The second insulating layer 340 is at least disposed on the side of the gallium arsenide layer 310 away from the laser emission direction of the laser structure 300, or in other words, the second insulating layer 340 is disposed on the side of the gallium arsenide layer 310 closer to the switching structure 200. In this case, the laser structure 300 is positioned above the switching structure 200. If the laser emission direction is taken upwards, then the second insulating layer 340 is located below the gallium arsenide layer 310.

[0070] In practical applications, the anode and cathode of an inverted laser structure 300 are usually located on the same side of the laser structure 300, while the anode and cathode of an upright laser structure 300 are usually located on opposite sides of the laser structure 300.

[0071] The first lead-out structure 410 is disposed in the second insulating layer 340, and the second insulating layer 340 is in direct contact with the first insulating layer 140. The first connection structure 420 is disposed in the second insulating layer 340 and the first insulating layer 140. The first lead-out structure 410 is electrically connected to the gallium arsenide layer 310, and the first connection structure 420 is in direct contact with the drain of the switching transistor 210. (Reference) Figure 2 As shown. If the switch structure 200 and the laser structure 300 are connected by bonding, the first connection structure 420 is a metal bonding layer disposed in the second insulating layer 340 and the first insulating layer 140.

[0072] In practical applications, considering that the laser structure 300 needs to be connected to an input voltage (Vin), the input voltage layer 350 of the laser structure 300 is disposed on the first insulating layer 140. The first electrode layer 330 and the second connection structure 440 are in direct contact. The second connection structure 440 and the input voltage layer 350 of the laser structure 300 are in direct contact. The second connection structure 440 is the metal bonding layer when the switch structure 200 and the laser structure 300 are connected. (Refer to...) Figure 2 As shown. That is, the first electrode layer 330 is electrically connected to the input voltage layer 350 of the laser structure 300 through the second connection structure 440, thereby realizing the connection of the input voltage to the laser structure 300.

[0073] Considering that the input voltage, drive input signal and drive power supply voltage all need to be provided externally, multiple grooves can be provided in the first insulating layer 140, and the grooves expose at least the drive power supply voltage layer 180, the drive input signal layer 190 and the input voltage layer 350.

[0074] As one possible implementation, a metal contact 610 is provided in the groove, as shown in the reference. Figure 2 As shown. The metal contact 610 is used for signal transmission with the outside world.

[0075] As another possible implementation, the integrated drive structure 100, switch structure 200, and laser structure 300 can be disposed on one side of a substrate 500. The substrate 500 also includes multiple metal layers, including a second metal layer 520, which is electrically connected to the input voltage layer 350 to provide an input voltage. A first insulating layer 140 includes multiple recesses, including a first recess 141 that exposes the input voltage layer 350 of the laser structure 300. The second metal layer 520 and the input voltage layer 350 of the laser structure 300 can be electrically connected using wire bonding 530. (See reference...) Figure 5 As shown. Accordingly, the drive power supply voltage layer 180 and the drive input signal layer 190 are also exposed by the groove, and can also be electrically connected to the metal layer on the substrate 500 by means of wire bonding 530.

[0076] In embodiments of this application, to further reduce the parasitic inductance of the optoelectronic integrated structure, the input voltage layer 350 of the laser structure 300 can be configured to extend from the first insulating layer 140 into the first substrate 110, and the switching structure 620 can be used to isolate the input voltage layer 350 of the laser structure 300 from the switching structure 200. Specifically, refer to... Figure 6As shown, the input voltage layer 350 of the laser structure 300 penetrates the interlayer dielectric 130, the first gallium nitride layer 120, and a portion of the thickness of the first substrate 110, thus enabling the anode of the laser structure 300 to be connected to the first substrate 110. An isolation structure 620 is disposed between the first gallium nitride layer 120 and the first substrate 110, and is also disposed around the input voltage layer 350. For example, the isolation structure 620 can be disposed between the source of the switching transistor 210 and the input voltage layer 350, and can be made of an insulating material, thereby isolating the ground potential of the switching structure 200 from the input voltage of the laser structure 300. By providing the isolation structure 620 and extending the input voltage layer 350 into the first substrate 110, the high parasitic inductance of the input voltage layer 350 caused by the wire bonding 530 can be completely eliminated, further improving the magnitude and speed of the pulse current.

[0077] Figure 6 In the first insulating layer 140, there are a first sub-insulating layer 143 and a second sub-insulating layer 144, with the second sub-insulating layer 144 located on the side of the first sub-insulating layer 143 away from the first substrate 110. The second sub-insulating layer 144 is used to assist in the integration of the switching structure 200 and the laser structure 300 into one unit.

[0078] In the second case, the driving structure 100, the switching structure 200, and the laser structure 300 are disposed on the substrate 500, and the first connection structure 420 includes a first metal layer 510 disposed on the substrate 500. That is, the switching structure 200 and the laser structure 300 are electrically connected by the first metal layer 510 disposed on the substrate 500.

[0079] Specifically, the substrate 500 can be a printed circuit board or a silicon interposer. The laser structure 300 and the switch structure 200 can be disposed on the same side of the substrate 500 or on both sides of the substrate 500, as described below:

[0080] As one possible implementation, the laser structure 300 and the switch structure 200 are disposed on both sides of the substrate 500, that is, the laser structure 300 and the switch structure 200 are disposed on both sides of the printed circuit board or the silicon interposer. To achieve the electrical connection between the drain of the switching transistor 210 and the first lead structure 410, the first metal layer 510 penetrates the substrate 500, that is, the first metal layer 510 penetrates the printed circuit board or the silicon interposer. (Refer to...) Figure 7 As shown.

[0081] Considering that the first metal layer 510 is disposed in the substrate 500, the first metal layer 510 and the drain of the switching transistor 210 and the first lead-out structure 410 may not be directly electrically connected. Therefore, a bottom bump metal layer (UBM) 540 and a ball grid array (BGA) 550 can be used to connect the first metal layer 510 and the drain of the switching transistor 210 and the first lead-out structure 410. (Refer to...) Figure 7 As shown, the ball grid array 550 is in direct contact with the first metal layer 510, and the bump-down metal layer 540 is in direct contact with the drain of the switching transistor 210 and the first lead-out structure 410.

[0082] The substrate 500 also includes multiple metal layers, i.e., the printed circuit board or silicon interposer includes multiple metal layers, including a second metal layer 520. The second metal layer 520 can also be electrically connected to the input voltage layer 350 using the under-bump metal layer 540 and the ball grid array 550. Correspondingly, the drive power supply voltage layer 180 and the drive input signal layer 190 can also be electrically connected to the metal layers on the substrate 500 using the under-bump metal layer 540 and the ball grid array 550.

[0083] As another possible implementation, the driving structure 100, laser structure 300, and switching structure 200 are disposed on the same side of the substrate 500, that is, the driving structure 100, laser structure 300, and switching structure 200 are disposed on the same side of the printed circuit board or silicon interposer. To achieve the electrical connection between the drain of the switching transistor 210 and the first lead structure 410, the first metal layer 510 is disposed on one side surface of the substrate 500, that is, the first metal layer 510 is disposed on one side surface of the printed circuit board or silicon interposer. (Refer to...) Figure 8 As shown.

[0084] The third scenario is that the laser emission direction of the laser structure 300 is along one side of the first electrode layer 330. In this case, along the laser emission direction, the structure of the laser structure 300 is, in sequence, a gallium arsenide layer 310, a diode structure 320, and the first electrode layer 330. That is, the gallium arsenide layer 310 is disposed on the side of the diode structure 320 close to the substrate 500, that is, the laser structure 300 is placed upright. At this time, the driving structure 100 and the switching structure 200 are also placed upright. That is, along the laser emission direction, they are, in sequence, a first substrate 110, a first gallium nitride layer 120, an interlayer dielectric 130, and a first insulating layer 140.

[0085] To achieve electrical connection between the drain of the switching transistor 210 and the cathode of the laser structure 300, the first lead structure 410 can directly contact the gallium arsenide layer 310 to achieve electrical connection. In this case, the first connection structure 420 may include a metal bump and an under-bump metal layer 540. The under-bump metal layer 540 directly contacts the drain of the switching transistor 210. (Refer to...) Figure 9 As shown. The first connection structure 420 can be a metal bonding layer formed when the laser structure 300 and the switch structure 200 are bonded, or a metal bonding layer formed when the laser structure 300 and the switch structure 200 are welded. When the metal bonding layer is formed when the laser structure 300 and the switch structure 200 are welded, the metal bonding layer can be a stacked structure of tin 421 / copper 422 / under-bump metal layer 540.

[0086] The substrate 500 also includes multiple metal layers, including a second metal layer 520. The second metal layer 520 is electrically connected to an input voltage layer to provide the input voltage. The second metal layer 520 and the first voltage layer 330 of the laser structure 300 can be electrically connected via wire bonding 530. (See reference...) Figure 9 As shown. The first insulating layer 140 includes a plurality of grooves, through which the drive power supply voltage layer 180 and the drive input signal layer 190 are exposed, and can also be electrically connected to the metal layer on the substrate 500 via wire bonding 530.

[0087] In practical applications, the laser emission direction of the laser structure 300 can be along one side of the gallium arsenide layer 310 or along one side of the first electrode layer 330, and can also be along the sidewall of the diode structure 320. (Refer to...) Figure 10 As shown. The laser structure 300 that emits light along one side of the gallium arsenide layer 310 or along one side of the first electrode layer 330 is a vertical cavity surface-emitting laser (VCSEL), and the laser structure 300 that emits light along the sidewall of the diode structure 320 is an edge-emitting laser (EEL).

[0088] The fourth scenario involves changing the circuit connection between the laser structure 300 and the switching structure 200. Specifically, the anode of the laser structure 300 and the source of the switching transistor 210 are electrically connected. This is achieved through the first electrode layer 330 and the source of the switching transistor 210, also via the first lead-out structure 410 and the first connection structure 420. Figure 11 The circuit connection is shown. At this time, the first lead-out structure 410 is not in contact with the gallium arsenide layer 310. At this time, the first lead-out structure 410 is not the cathode of the laser structure 300. A second electrode layer 360 can be additionally provided. The second electrode layer 360 is in direct contact with the gallium arsenide layer 310, that is, the second electrode layer 360 constitutes the cathode of the laser structure 300. The second electrode layer 360 is in direct contact with the ground metal layer 370 on the substrate 500 to achieve electrical connection. The ground metal layer 370 is connected to the ground potential.

[0089] To achieve electrical connection between the first electrode layer 330 and the source of the switching transistor 210 using the first lead-out structure 410 and the first connection structure 420, the laser structure 300, the switching structure 200 and the driving structure 100 can be disposed on the same side of the substrate 500. In this case, the interlayer dielectric 130 is disposed on the surface of the first insulating layer 140 away from the substrate 500, and the gallium arsenide layer 310 is disposed on the surface of the diode structure 320 close to the substrate 500. That is, the switching structure 200 and the driving structure 100 are placed upside down, and the laser structure 300 is placed upright.

[0090] The substrate 500 also includes multiple metal layers, which can directly contact the power supply voltage layer 180, the drive input signal layer 190, and the power supply voltage layer 230 of the switching transistor 210. In this case, the first connection structure 420 can be a first metal layer 510 disposed on the substrate, and the first lead-out structure 410 can include a wire bonding 530 or a through-silicon via contact 560 connecting the first metal layer 510 and the first electrode layer 330. (See reference...) Figure 12 and Figure 13 As shown.

[0091] When the first lead-out structure 410 is a through-hole contact 560, the through-hole contact 560 can be formed using a through-silicon via (TSV) process where metal is backfilled after the through-hole is formed. The through-hole contact 560 can further shorten the distance between the laser structure 300 and the switch structure 200, reducing parasitic inductance. At this time, the substrate 500 is a packaging substrate, and the laser structure 300, switch structure 200, and drive structure 100 can be jointly packaged using a system-in-package (SIP) process, that is, the laser structure 300, switch structure 200, and drive structure 100 can be packaged using the packaging layer 570.

[0092] Therefore, although wire bonding, metal bonding layer, through-hole contact or metal layer on substrate may be used when electrically connecting laser structure 300 and switch structure 200, compared with packaging laser structure 300 as a discrete device and then electrically connecting it with switch structure 200, the electrical signal transmission distance is shortened, thereby reducing parasitic inductance, reducing loss, and ultimately improving detection accuracy.

[0093] Based on the optoelectronic integrated structure provided in the above embodiments, this application also provides a method for manufacturing an optoelectronic integrated structure, referencing... Figure 14 The diagram shown is a flowchart illustrating a method for manufacturing an optoelectronic integrated structure according to an embodiment of this application.

[0094] The manufacturing method of the optoelectronic integrated structure provided in this application includes the following steps:

[0095] S101, Obtain the driving structure, switching structure, and laser structure, referencing... Figure 15 As shown.

[0096] In the embodiments of this application, a driving structure 100, a switching structure 200, and a laser structure 300 can be obtained. The driving structure 100 and the switching structure 200 include a first substrate 110, a first gallium nitride layer 120, an interlayer dielectric 130, and a first insulating layer 140, which are sequentially stacked. The first substrate 110 can be a semiconductor material, such as silicon. The interlayer dielectric 130 can be an insulating material; for example, the material of the interlayer dielectric 130 can be silicon oxide formed using a vapor deposition process. The interlayer dielectric 130 may include a first interlayer dielectric 131 and a second interlayer dielectric 132, with the second interlayer dielectric 132 disposed on the surface of the first interlayer dielectric 131 away from the first substrate 110. The driving structure 100 includes a driving transistor 150, which includes a source, a drain, and a gate, wherein the source is represented by S, the drain by D, and the gate by G. The driving transistor 150 is mainly disposed in the interlayer dielectric 130.

[0097] The switching structure 200 includes a switching transistor 210, which includes a source, a drain, and a gate. The source is represented by S, the drain by D, and the gate by G. The switching transistor 210 is mainly disposed in the interlayer dielectric 130.

[0098] The source of the driving transistor 150, the source of the switching transistor 210, and the drain of the switching transistor 210 penetrate at least through the interlayer dielectric 130 and a portion of the thickness of the first insulating layer 140, and the source of the driving transistor 150 and the source of the switching transistor 210 are electrically connected.

[0099] The laser structure 300 includes a gallium arsenide layer 310, a diode structure 320, and a first electrode layer 330 stacked sequentially. The structure electrically connected to the gallium arsenide layer 310 can serve as the cathode of the laser structure 300. For example, if the first lead-out structure 410 is in contact with the gallium arsenide layer 310, then the first lead-out structure 410 can serve as the cathode of the laser structure 300. The first electrode layer 330 can serve as the anode of the laser structure 300. The diode structure 320 is formed by stacking multiple film layers and can perform photoelectric conversion to generate laser light, thereby enabling laser emission from the laser structure 300.

[0100] S102, etch the first insulating layer to form multiple openings, reference. Figure 16 As shown.

[0101] In embodiments of this application, the first insulating layer 140 may be etched to form a plurality of openings 142, which expose at least the drain or source of the switching transistor 210. The openings 142 also expose the drive supply voltage layer 180 and the drive input signal layer 190.

[0102] S103, fill the opening with metal to form a metal bonding layer, reference. Figure 17 As shown.

[0103] In an embodiment of this application, a metal material is filled into the opening 142 to form a metal bonding layer, which constitutes the first connection structure 420.

[0104] S104, electrically connects the first lead-out structure and the gallium arsenide layer or the first electrode layer, reference Figure 2 As shown.

[0105] In the embodiments of this application, the first lead-out structure 410 and the gallium arsenide layer 310 or the first electrode layer 330 are electrically connected using a bonding or welding process. The first lead-out structure 410 and the first connection structure 420 are in direct contact, and the first connection structure 420 is in direct contact with the source or drain of the switching transistor 210. The first connection structure 420 includes a first metal layer disposed on the substrate or a metal bonding layer disposed when the switching structure 200 and the laser structure 300 are connected. The substrate is used to place the driving structure 100, the switching structure 200, and the laser structure 300.

[0106] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the method embodiments are basically similar to the structural embodiments, so they are described more simply; relevant parts can be referred to the descriptions of the structural embodiments.

[0107] The above description is merely a preferred embodiment of this application. Although this application has disclosed preferred embodiments above, it is not intended to limit this application. Any person skilled in the art can make many possible variations and modifications to the technical solutions of this application using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solutions of this application. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this application without departing from the content of the technical solutions of this application shall still fall within the protection scope of the technical solutions of this application.

Claims

1. An optoelectronic integrated structure, characterized in that, The optoelectronic integrated structure comprises a driving structure, a switching structure and a laser structure; The driving structure and the switching structure comprise a first substrate, a first gallium nitride layer, an interlayer medium and a first insulating layer which are sequentially stacked; the driving structure comprises a driving transistor, and the switching structure comprises a switching transistor; a source of the driving transistor, a source of the switching transistor and a drain of the switching transistor at least penetrate the interlayer medium and a partial thickness of the first insulating layer; the source of the driving transistor and the source of the switching transistor are electrically connected; The laser structure comprises a gallium arsenide layer, a diode structure and a first electrode layer which are sequentially stacked; The first lead-out structure is electrically connected with the gallium arsenide layer or the first electrode layer; the first lead-out structure directly contacts with the first connection structure; and the first connection structure directly contacts with the source of the switching transistor or the drain of the switching transistor. The first connection structure comprises a first metal layer of a substrate or a metal bonding layer when the switching structure and the laser structure are connected; and the substrate is used for placing the driving structure, the switching structure and the laser structure.

2. The optoelectronic integrated structure of claim 1, wherein, The laser structure comprises a second insulating layer which is arranged at least on a side of the gallium arsenide layer away from a laser emission direction of the laser structure; and the laser emission direction of the laser structure is along a side of the gallium arsenide layer for light emission. The first lead-out structure is arranged in the second insulating layer; the second insulating layer contacts with the first insulating layer; the first connection structure is arranged in the second insulating layer and the first insulating layer; the first lead-out structure is electrically connected with the gallium arsenide layer; and the first connection structure directly contacts with the drain of the switching transistor.

3. The optoelectronic integrated structure of claim 2, wherein, An input voltage layer of the laser structure is arranged in the first insulating layer; The first electrode layer directly contacts with a second connection structure; and the second connection structure directly contacts with the input voltage layer of the laser structure. The second connection structure is a metal bonding layer when the switching structure and the laser structure are connected.

4. The optoelectronic integrated structure of claim 3, wherein, The substrate further comprises a second metal layer; the first insulating layer further comprises a first recess; the first recess exposes the input voltage layer of the laser structure; and the second metal layer and the input voltage layer of the laser structure are electrically connected by wire bonding.

5. The optoelectronic integrated structure of claim 3, wherein, The input voltage layer of the laser structure penetrates the interlayer medium, the first gallium nitride layer and a partial thickness of the first substrate; An isolation structure is arranged in the first gallium nitride layer and the first substrate, and is used for isolating the input voltage layer of the switching structure and the laser structure.

6. The optoelectronic integrated structure of claim 1, wherein, The substrate is a printed circuit board or a silicon interposer; the laser structure and the switching structure are arranged on two sides of the printed circuit board or the silicon interposer; and the first metal layer penetrates the printed circuit board or the silicon interposer.

7. The optoelectronic integrated structure of claim 1, wherein, The substrate is a printed circuit board or a silicon interposer; the laser structure, the switching structure and the driving structure are arranged on the same side of the printed circuit board or the silicon interposer; and the first metal layer is arranged on a side surface of the printed circuit board or the silicon interposer.

8. The optoelectronic integrated structure of claim 1, wherein, The laser structure, the switch structure and the driving structure are arranged on the same side of the substrate, the interlayer medium is arranged on the side surface of the first insulating layer away from the substrate, and the gallium arsenide layer is arranged on the side surface of the diode structure close to the substrate. The first lead-out structure is electrically connected with the first electrode layer, and the first connection structure is directly contacted with the source of the switch transistor.

9. The optoelectronic integrated structure of claim 8, wherein, The first connection structure includes a first metal layer arranged on the substrate, and the first lead-out structure includes a wire bonding or a via contact connecting the first metal layer and the first electrode layer.

10. The optoelectronic integrated structure of claim 1, wherein, The gallium arsenide layer is arranged on the side surface of the diode structure close to the substrate, and the first lead-out structure is electrically connected with the gallium arsenide layer. The first connection structure includes an under bump metal layer, and the under bump metal layer is directly contacted with the drain of the switch transistor.

11. The optoelectronic integrated structure of claim 10, wherein, The laser emission direction of the laser structure is along the side surface of the gallium arsenide layer, the side surface of the first electrode layer, or along the sidewall of the diode structure.

12. A method of fabricating an optoelectronic integrated structure, characterized by, The method comprises: obtaining a driving structure, a switch structure and a laser structure, the driving structure and the switch structure comprising a first substrate, a first gallium nitride layer, an interlayer medium and a first insulating layer arranged in sequence; the driving structure comprises a driving transistor, and the switch structure comprises a switch transistor; the source of the driving transistor, the source of the switch transistor and the drain of the switch transistor at least penetrate the interlayer medium and part of the thickness of the first insulating layer, and the source of the driving transistor is electrically connected with the source of the switch transistor; the laser structure comprises a gallium arsenide layer, a diode structure and a first electrode layer arranged in sequence; etching the first insulating layer to form a plurality of openings, and the plurality of openings at least expose the drain or the source of the switch transistor; filling metal in the openings to form a metal bonding layer; electrically connecting a first lead-out structure with the gallium arsenide layer or the first electrode layer, the first lead-out structure being directly contacted with a first connection structure, and the first connection structure being directly contacted with the source of the switch transistor or the drain of the switch transistor; The first connection structure includes a first metal layer arranged on the substrate or a metal bonding layer when the switch structure and the laser structure are connected; The substrate is used for placing the driving structure, the switch structure and the laser structure.

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