Optical communication functional device layer, optical communication chip and preparation method and application thereof

Abstract

This application relates to an optical communication functional device layer, an optical communication chip, and their fabrication methods and applications. The optical communication functional device layer includes a stacked first functional layer, an optical functional layer, and a second functional layer, with a transmitter or receiver respectively formed within the first and second functional layers. This structure introduces an optical functional layer between the first and second functional layers. This optical functional layer can change the direction of light transmission, thereby directly avoiding optical path obstruction between the transmitter and receiver at the physical level. This provides a new direction for realizing the vertical stacking of transmitters and receivers, further improving the isolation reliability between the transmitter and receiver. It is beneficial to integrate more functional devices within a unit projected area, increasing functional integration density. Furthermore, the optical communication functional device layer can be customized according to requirements, manufactured and sold as an independent component, and combined with other functional chips to form differentiated small-size, high-communication-density optical communication chips.

Description

Technical Field

[0001] This application relates to the field of optical communication technology, and in particular to an optical communication functional device layer, an optical communication chip, and their fabrication methods and applications. Background Technology

[0002] Visible Light Communication (VLC) technology utilizes the visible light band for wireless data transmission. Due to its abundant spectrum resources and lack of electromagnetic interference, it is considered one of the next-generation core communication technologies and has promising applications in intelligent transportation, the Internet of Things, and high-speed indoor communication. To achieve miniaturization and low-cost application of terminal devices, the "transceiver integration" solution, which integrates the optical transmitter and receiver into a single chip, has become the mainstream development direction.

[0003] Currently, the mainstream technology for realizing transceiver chips is horizontal integration, which integrates the optical transmitter and receiver side-by-side on the same substrate plane. While this integration method can meet the requirements of chip transceiver integration, it also faces several challenges. On the one hand, in a horizontal layout, the optical transmitter and receiver inevitably occupy a large substrate area, and to prevent optical crosstalk, an isolation structure needs to be set between the optical transmitter and receiver, thus limiting further reduction in chip size and improvement in integration density. On the other hand, since the optical transmitter is usually composed of LEDs made of semiconductor materials such as gallium nitride and indium phosphide, and the optical receiver is usually composed of silicon-based photodetectors, the specific structures and materials used in the optical transmitter and receiver are quite different. Therefore, in the fabrication process, to efficiently and reliably integrate the optical transmitter and receiver heterogeneously on the same substrate, a relatively complex layered fabrication process is required, which limits both the reduction of chip production costs and the improvement of production capacity. Summary of the Invention

[0004] This application aims to provide an optical communication functional device layer, an optical communication chip, and their fabrication methods and applications, in order to break through the limitations of traditional lateral integration on chip size, thereby improving integration density, achieving chip miniaturization and high performance, and further reducing the complexity of the manufacturing process.

[0005] The purpose of this application is to achieve the following technical solution: This application provides an optical communication functional device layer, including a first functional layer, an optical functional layer and a second functional layer stacked together; The first functional layer includes a transmitter, and the second functional layer includes a receiver; or, the first functional layer includes a receiver, and the second functional layer includes a transmitter. The optical functional layer is located between the first functional layer and the second functional layer. The optical functional layer is used to change the transmission direction of the optical signal so that the light emitted or received by the device in the first functional layer does not pass through the device in the second functional layer. The transmitter is used to convert electrical signals into optical signals, and the receiver is used to convert optical signals into electrical signals.

[0006] In one embodiment, the transmitters are arrayed in the first functional layer and the receivers are arrayed in the second functional layer; or, the transmitters are arrayed in the second functional layer and the receivers are arrayed in the first functional layer.

[0007] This application also provides an optical communication chip, including a superimposed processing circuit layer and an optical communication functional device layer as described in any of the foregoing solutions; The first functional layer is located on the side close to the processing circuit layer; both the transmitter and the receiver are electrically connected to the processing circuit layer, which is used to process the input or output electrical signals.

[0008] In one embodiment, the optical communication chip further includes an optical coupling layer, which is stacked on the second functional layer and is used to perform optical shaping processing on the input or output optical signals.

[0009] In one embodiment, an optical lens array is disposed within the optical coupling layer, wherein the optical lenses are disposed in a one-to-one correspondence with the transmitter and the receiver; or, the optical coupling layer comprises a photonic crystal material or has a metasurface structure.

[0010] In one embodiment, the optical communication chip further includes a wiring layer located between the processing circuit layer and the first functional layer. The wiring layer and the processing circuit layer are connected in the same or different ways.

[0011] In one embodiment, the routing layer is hybrid-bonded to the first functional layer, and the routing layer is bump-bonded to the processing circuit layer; Alternatively, the wiring layer and the first functional layer are mixed-bonded, and the wiring layer and the processing circuit layer are mixed-bonded; Alternatively, the routing layer is bonded to the first functional layer via bump bonding, and the routing layer is bonded to the processing circuit layer via hybrid bonding. Alternatively, the wiring layer is directly fabricated on the first functional layer, and the wiring layer and the processing circuit layer are bonded by bump bonding or hybrid bonding; Alternatively, the wiring layer may be directly fabricated on the processing circuit layer, and the wiring layer may be bonded to the first functional layer via bump bonding or hybrid bonding.

[0012] This application also provides a method for fabricating an optical communication chip, comprising the following steps: A first wafer is provided, which includes a first functional layer or at least two first functional layers, wherein the first functional layer includes a plurality of first devices; Provide a second functional layer or a second wafer containing at least two second functional layers, wherein the second functional layer includes a plurality of second devices; Provide a processing circuit layer or a third wafer containing at least two processing circuit layers; Provides an optical functional layer or a fourth wafer containing at least two optical functional layers; The first functional layer or first wafer, the second functional layer or second wafer, the processing circuit layer or third wafer, and the optical functional layer or fourth wafer are connected to make the first device and the second device both connected to the processing circuit layer, with the first functional layer located on the side closer to the processing circuit layer, and the optical functional layer located between the first functional layer and the second functional layer. The first device and the second device are respectively selected from one or the other of a transmitter and a receiver.

[0013] In one embodiment, the step of connecting the first functional layer or first wafer, the second functional layer or second wafer, the processing circuit layer or third wafer, and the optical functional layer or fourth wafer specifically includes the following: The first wafer, the second wafer, the third wafer, and the fourth wafer are bonded together so that the four wafers are stacked in the order of the third wafer, the first wafer, the fourth wafer, and the second wafer, and the bonded structure is then cut. Alternatively, the first wafer, the second wafer, and the fourth wafer are bonded together, such that the three wafers are stacked in the order of the first wafer, the fourth wafer, and the second wafer, and the bonded structure is cut to obtain the first intermediate chip, and then the first intermediate chip is bonded to the processing circuit layer. Alternatively, the first functional layer, the second functional layer, the optical functional layer, and the processing circuit layer can be bonded together.

[0014] In one embodiment, the preparation method further includes the following steps: The step of providing an optical coupling layer or an optical coupling wafer containing at least two optical coupling layers, and connecting the optical coupling layer or optical coupling wafer and the second functional layer or second wafer to stack the optical coupling layer on the second functional layer.

[0015] In one embodiment, the step of connecting the optical coupling layer or optical coupling wafer, the second functional layer or second wafer specifically includes the following: Bonding the optical coupling layer to the second functional layer; Alternatively, the optically coupled wafer can be bonded to the second wafer, and the bonded structure can be cut. Alternatively, an optical coupling layer can be fabricated directly on the second functional layer; Alternatively, an optically coupled wafer can be fabricated directly on the second wafer, and the structure formed after the optically coupled wafer is cut.

[0016] In one embodiment, the preparation method further includes the following steps: The step of providing a wiring layer or a carrier wafer containing at least two wiring layers, and connecting the wiring layer or the carrier wafer, a first functional layer or a first wafer, and a processing circuit layer or a third wafer so that the wiring layer is located between the first functional layer and the processing circuit layer.

[0017] In one embodiment, the step of connecting the wiring layer or the carrier wafer, the first functional layer or the first wafer, and the processing circuit layer or the third wafer specifically includes the following: The first wafer, the carrier wafer, and the third wafer are bonded together so that the three wafers are stacked in the order of the third wafer, the carrier wafer, and the first wafer, and the bonded structure is then cut. Alternatively, the first wafer and the carrier wafer are bonded together, and the bonded structure is cut to obtain the second intermediate chip, which is then bonded to the processing circuit layer. Alternatively, the carrier wafer and the third wafer are bonded together, and the bonded structure is cut to obtain the third intermediate chip, and then the third intermediate chip is bonded to the first functional layer. Alternatively, the first functional layer, the wiring layer, and the processing circuit layer can be bonded together. Alternatively, a carrier wafer can be fabricated directly on the first wafer and cut to form a wiring layer, and then the processing circuit layer can be bonded to the wiring layer.

[0018] This application also provides an optical communication terminal, including an optical communication chip as described in any of the foregoing solutions.

[0019] This application also provides an optical communication system, including at least two optical communication terminals as described in the foregoing scheme.

[0020] Compared with the prior art, this application has the following beneficial effects: 1. The optical communication functional device layer of this application arranges transmitters or receivers in the first and second functional layers respectively, and introduces an optical functional layer between the first and second functional layers. The optical functional layer can change the direction of light transmission, thereby directly avoiding the occupancy of the optical path between the transmitter and the receiver at the physical level. This provides a new direction for the vertical stacking of transmitters and receivers. That is, even if the projections of the transmitter and receiver overlap in the vertical direction, the optical paths between the light emitted by the transmitter and the light received by the receiver are independent. This can further improve the isolation reliability between the transmitter and the receiver, which is conducive to integrating more functional devices in a unit projection area and increasing the functional integration density. Moreover, this structure can be customized according to needs and manufactured and sold as an independent component to cooperate with other functional chips to form differentiated small-size high-density optical communication chips.

[0021] 2. The optical communication chip of this application introduces an optical functional layer between the first and second functional layers. This optical functional layer alters the direction of light transmission, causing the light signals emitted or received between the first functional layers to be deflected or guided at a specific angle, thus preventing them from passing through the devices in the second functional layer. This provides greater design freedom and improved isolation reliability for chip stack-up designs. In this architecture, the transmitting (or receiving) devices in the first functional layer and the receiving (or transmitting) devices in the second functional layer can overlap in a horizontal projection, multiplying the number of functional devices that can be integrated within a unit projection area, making ultra-high-density integration possible. Simultaneously, the vertically stacked structure ensures that the lateral size of the chip is determined only by the size of a single functional layer, enabling chip miniaturization. Furthermore, this structure helps overcome the limitations of traditional planar integration where transmitters and receivers must be arranged side-by-side, restricting fabrication processes and workflows. Based on this structure, transmitters and receivers can be fabricated simultaneously before integration, significantly improving processing efficiency and reducing production costs.

[0022] 3. The method for fabricating the optical communication chip in this application involves first forming the processing circuit layer, each functional device layer, and the optical functional layer independently, and then combining and connecting them. This modular fabrication process allows the transmitter and receiver to be processed separately under their respective optimal process conditions, avoiding the problem of complex layered fabrication of heterogeneous materials on the same substrate and simplifying the overall process flow. At the same time, this method can also overcome the limitations of the processing location, allowing the processing circuit layer and each functional device layer to be fabricated by different manufacturers and then integrated in a unified manner, improving processing efficiency. In addition, this method supports bonding the processing circuit layer and each functional device layer in wafer form and then dicing them, which is conducive to large-scale mass production and reduces manufacturing costs.

[0023] 4. The optical communication terminal of this application, by using an optical communication chip with small lateral size and high functional integration density, can save the space occupied by the optical communication chip inside the terminal, thereby enabling the optical communication terminal to achieve significant miniaturization and weight reduction, while ensuring high-density communication of the optical communication terminal.

[0024] 5. The optical communication system of this application, by employing at least two high-density communication optical terminals, can achieve multi-channel parallel data transmission. Compared with traditional communication systems, this enables the optical communication system to achieve higher link density and parallel communication capabilities, thereby improving the overall throughput and capacity of the system. Furthermore, from a manufacturing and deployment perspective, the scalability potential of the optical communication chip fabrication method helps reduce the cost of a single optical communication terminal, thereby reducing the deployment and maintenance costs of the entire optical communication system. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of an optical communication chip according to an embodiment of this application; Figure 2 This is a schematic diagram of the structure of the optical communication chip according to the second embodiment of this application; Figure 3 This is a schematic diagram of the structure of the optical communication chip according to the third embodiment of this application; Figure 4 This is a flowchart of a method for fabricating an optical communication chip according to one embodiment of this application; Figure 5 This is a schematic diagram of the optical communication system of this application.

[0026] Explanation of reference numerals in the attached figures: 001, Optical communication functional device layer; 100, Processing circuit layer; 101, Processing unit; 102, Bonding wire; 110, Transmitter; 120, Receiver; 200, First functional layer; 210, First dielectric layer; 300, Optical functional layer; 400, Second functional layer; 410, Second dielectric layer; 500, Optical coupling layer; 510, Light lens array; 600, Wiring layer. Detailed Implementation

[0027] 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. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0028] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] In the semiconductor field, a wafer generally refers to a structure that, after semiconductor processing, is uncut and typically contains multiple chips and reserved dicing spaces. A chip generally refers to an independent unit with complete functionality, formed by cutting a wafer according to the reserved dicing spaces. Bonding generally refers to the process of combining two wafers, two chips, or one wafer and one chip together using physical or chemical methods. If a layer structure is grown directly on the surface of a chip or wafer, the connection between that layer structure and the chip or wafer does not fall under the category of bonding.

[0031] With the development of visible light communication technology towards miniaturization and high integration of terminal devices, the "transceiver" architecture, which integrates optical transmission and reception functions into a single chip, has become an inevitable trend. However, the current mainstream lateral integration scheme, which places the optical transmitter and receiver side by side on the same plane, has inherent limitations. The device layout occupies a large lateral substrate area, and the physical isolation structure set up to prevent optical crosstalk further restricts the reduction of chip size and the improvement of integration density. To overcome the above technical obstacles, this application provides a new optical communication functional device layer, an optical communication chip, and its fabrication method and application. In this technical solution, the traditional planar layout is abandoned, and a vertical stacking integration method is adopted. The following will be combined with the appendix... Figure 1-5 Through multiple specific embodiments, the optical communication functional device layer, optical communication chip, and their fabrication methods and applications of this application are described.

[0032] Please see Figure 1 In one embodiment, the optical communication chip provided in this application includes a stacked processing circuit layer 100 and an optical communication functional device layer 001.

[0033] The optical communication functional device layer 001 and the processing circuit layer 100 are electrically connected. The optical communication functional device layer 001 is used to transmit, receive, and convert photoelectric signals, while the processing circuit layer 100 is used to process the signals transmitted and received by the optical communication functional device layer 001. The two work together to realize the optical communication function.

[0034] It is understandable that the optical communication functional device layer 001 and the processing circuit layer 100 can exist as independent chips for manufacturing, sales, and integration, thereby increasing the flexibility of optical communication chip fabrication.

[0035] Please continue reading. Figure 1 Specifically, in one embodiment, the optical communication functional device layer 001 includes a first functional layer 200, an optical functional layer 300, and a second functional layer 400 stacked together.

[0036] The first functional layer 200 includes a first dielectric layer 210 and a plurality of transmitters 110 distributed within the first dielectric layer 210. The transmitters 110 are used to convert electrical signals output from the processing circuit layer 100 into optical signals and output them. The second functional layer 400 includes a second dielectric layer 410 and a plurality of receivers 120 distributed within the second dielectric layer 410. The receivers 120 are aligned with the transmitters 110 one by one. The receivers 120 are used to convert the input optical signals into electrical signals and input them to the processing circuit layer 100 for data processing. The optical functional layer 300 is located between the first functional layer 200 and the second functional layer 400. The optical functional layer 300 is used to change the transmission direction of the optical signals so that the light emitted by the transmitters 110 is transmitted from the second dielectric layer 410 without passing through the receivers 120.

[0037] In practical applications, when the visible light communication chip needs to transmit information, the processing circuit layer 100 sends an output electrical signal to the transmitter 110 according to the information to be transmitted. The transmitter 110 converts the received output electrical signal into an optical signal through photoelectric conversion. That is, the transmitter 110 emits light with different amplitudes or frequencies according to the control of the processing circuit layer 100. By controlling the amplitude of the light, the brightness of the light can be controlled to form changes in brightness. By controlling the frequency of the light, the rate of change in brightness can be controlled. Subsequently, the optical signal emitted by the transmitter 110 passes through the optical functional layer 300. Under the action of the optical functional layer 300, the transmission direction of the optical signal will change and be transmitted to the second dielectric layer 410 of the second functional layer 400 before being emitted. That is, under the action of the optical functional layer 300, the output optical signal will not pass through the receiver 120 on the second functional layer 400. When the visible light communication chip is needed to receive information, the receiver 120 receives the optical signal and performs photoelectric conversion on the received optical signal to form an electrical signal. That is, the receiver 120 generates a current under light irradiation. Subsequently, the receiver 120 transmits the formed electrical signal to the processing circuit layer 100. The processing circuit layer 100 performs data calculation and processing on the received input electrical signal and converts it into information. Since the transmission of electrical signals is based on electrical conductors, the optical functional layer 300 does not affect the transmission process of electrical signals.

[0038] It is understood that in this embodiment, by adding an optical functional layer 300 between the first functional layer 200 and the second functional layer 400, the light emitted by the transmitter 110 will not be received by the receiver 120 when the transmitter 110 and the receiver 120 are vertically aligned, thereby ensuring normal communication.

[0039] The optical communication chip provided in this embodiment, by introducing a dedicated optical functional layer 300, can physically avoid optical path obstruction between the transmitter 110 and the receiver 120 by changing the transmission direction of the optical signal. Control of the optical transmission path is achieved between the vertically stacked processing circuit layer 100, the first functional layer 200, and the second functional layer 400, thus enabling independent communication optical paths even when the transmitter 110 and receiver 120 are overlapped in the projection. This allows the transmitter 110 and receiver 120 to be aligned in the vertical projection without sacrificing layout density for isolation, further freeing up the chip's lateral space and providing a new technical path for achieving extreme chip size reduction and increased integration density. Simultaneously, this structure helps overcome the limitations of traditional planar integration where the transmitter and receiver must be horizontally arranged side-by-side, restricting fabrication processes and workflows. Based on this structure, the transmitter and receiver can be fabricated simultaneously before integration, significantly improving processing efficiency and reducing production costs.

[0040] Please see Figure 2 In other embodiments, the receiver 120 may be disposed on the first functional layer 200, and the transmitter 110 may be disposed on the second functional layer 400, that is, in Figure 2 In the illustrated embodiment, the receiver 120 is closer to the processing circuit layer 100, while the transmitter 110 is farther away from the processing circuit layer 100.

[0041] In practical applications of this embodiment, when the visible light communication chip is used to send information, the processing circuit layer 100 outputs an output electrical signal. This output electrical signal first passes through the first dielectric layer 210 and the optical functional layer 300 on the first functional layer 200 before being transmitted to the transmitter 110 for photoelectric conversion to form an optical signal output. When the visible light communication chip is used to receive information, the input optical signal also first passes through the second dielectric layer 410 on the second functional layer 400, then changes direction through the optical functional layer 300, and is then received by the receiver 120. Therefore, in this embodiment, the transmission paths of both the output electrical signal and the input optical signal before photoelectric conversion are prolonged, resulting in a less efficient use. Figure 1 The embodiments shown may be somewhat weakened.

[0042] Please return Figure 1 In one embodiment, the transmitter 110 and receiver 120 are arranged in an array in the first functional layer 200 and the second functional layer 400, respectively. Array arrangement refers to the arrangement of multiple functionally identical optoelectronic devices (such as multiple miniature light-emitting diodes or photodetectors) in a single device layer plane according to a preset, regular geometric pattern (such as a matrix). Specifically, for example, a standard spacing is used for layout to precisely match the interface requirements of multi-channel optical modules. Array arrangement allows a single chip to integrate a large number of independent optical transmitting or receiving units within a unit projected area, thereby multiplying the number of communication channels and total data throughput of the chip. Simultaneously, the regular array layout also facilitates the standardized design of subsequent optical coupling and electrical interconnection.

[0043] In one embodiment, a device array includes at least 20 transmitters 110 or 20 receivers 120 to achieve area array high-density communication. In other embodiments, the number of transmitters 110 and the number of receivers 120 may also be different.

[0044] In one embodiment, the first functional layer 200 includes a micrometer-scale array of Micro-LEDs, where each Micro-LED is a transmitter 110. This configuration improves modulation bandwidth and disperses heat sources, thereby facilitating high-density communication. The specific Micro-LED structure is the same as in the prior art and will not be described in detail here. The second functional layer 400 includes a micrometer-scale array of PD photodiodes, where each PD photodiode is a receiver 120. The receiver 120 can be selected from PN photodiodes or PIN photodiodes. The specific structure of the PD photodiodes is the same as in the prior art and will not be described in detail here.

[0045] In one embodiment, the optical functional layer 300 located between the two functional layers is the core of this solution for achieving optical isolation. It is a dielectric layer or structured functional layer capable of actively changing the direction of optical signal transmission within it. Its function is to deflect or guide the path of light (whether emitted or received external light) to avoid the active region of the devices in the second functional layer 400 during propagation. Specifically, this can be achieved using chiral photonic structures or non-reciprocal optics principles, or by integrating a miniaturized optical isolator structure. This optical functional layer 300 allows emitted light to be guided laterally or bypass the upper device via a specific path, even when the transmitter 110 and receiver 120 are perfectly aligned in vertical projection. Externally incident light can be guided to the lower device via complementary paths. Based on the active optical path control method, greater freedom can be provided for chip layout, making it possible to maximize the number of devices per unit projected area, thereby supporting further miniaturization of chip size and increased integration density.

[0046] It is understood that in other embodiments, the transmitter 110 and receiver 120 may also be misaligned, meaning that the projections of the transmitter 110 and receiver 120 onto the processing circuit layer 110 may completely overlap or partially overlap, and the spacing between the transmitter 110 and receiver 120 can be set according to actual needs. The scheme where the projections completely overlap can maximize the utilization of the chip's valuable lateral area, enabling higher functional density.

[0047] It is also understandable that the optical communication functional device layer 200 allows the first functional layer 200 and the second functional layer 400 to be fabricated under their respective optimal process conditions before being bonded.

[0048] Please return Figure 1In one embodiment, a plurality of processing units 101 are formed within the processing circuit layer 100. Each processing unit 101 corresponds to a transmitter 110 and / or a receiver 120, and each processing unit 101 processes data information transmitted by the transmitter 110 or received by the receiver 120 it is connected to. Each processing unit 101 may further include digital logic units, analog driving circuits, signal conditioning circuits, and possibly memory units, thereby providing precise electrical control and signal processing capabilities for each transmitter 110 or receiver 120 above it. The processing circuit layer 100 may be implemented using CMOS, DMOS, or BiCMOS processes, as long as the processing circuit layer 100 can provide precise electrical control and signal processing capabilities for each transmitter 110 or receiver 120 above it. That is, the transmitter 110 and receiver 120 can focus on efficient photoelectric conversion, while all complex signal generation, modulation, demodulation, and processing tasks are handled by the lower specialized processing circuit layer.

[0049] Please continue reading. Figure 1 In one embodiment, the first functional layer 20, the optical functional layer 300, the second functional layer 400, and the processing circuit layer 100 are all directly connected, meaning that no other functional layers are included between the first functional layer 200, the optical functional layer 300, the second functional layer 400, and the processing circuit layer 100. This configuration reduces the vertical interconnection distance between the first functional layer 200, the optical functional layer 300, the second functional layer 400, and the processing circuit layer 100, thereby shortening the transmission distance of optical or electrical signals, reducing signal loss, and also helping to reduce signal delay and increase access bandwidth, thus achieving high-speed, high-bandwidth optical communication.

[0050] In other embodiments, other functional layers may be provided between the first functional layer 200, the optical functional layer 300, the second functional layer 400, and the processing circuit layer 100 as needed.

[0051] Please see Figure 3 , Figure 3 A novel connection method between a processing circuit layer 100 and a first functional layer 200 is demonstrated. In this embodiment, the optical communication chip also includes a routing layer 600, which is located between the processing circuit layer 100 and the first functional layer 200. The connection method between the routing layer 600 and the processing circuit layer 100, and the connection method between the routing layer 100 and the first functional layer 200, may be the same or different.

[0052] Please continue reading. Figure 3The wiring layer 600 can be understood as an intermediate substrate containing high-density redistributed wiring (RDL) and vertical interconnect vias (such as through-silicon vias, TSVs). That is, the processing circuit layer 100 and the first functional layer 200 can be indirectly connected through the wiring layer 600. The configuration of the wiring layer 600 allows for differentiated designs in the connection between the wiring layer 600 and the first functional layer 200 or the processing circuit layer 100. This facilitates the adaptation of the optical communication functional device layer 001 to processing circuit layers 100 with different pin pitches and process nodes, without altering the precision packaging of the optical communication functional device layer 001 itself. This enhances the compatibility and design flexibility of the optical communication functional device layer 200 with various external driver / processing units.

[0053] Please continue reading. Figure 3 In one embodiment, the wiring layer 600 is hybrid-bonded to the first functional layer 200, and the wiring layer 600 is bump-bonded to the processing circuit layer 100. Hybrid bonding provides extremely high interconnect density and excellent electrical performance, making it well-suited for the large number of fine-pitch electrical connections required between the first functional layer 200 and the wiring layer 600; while bump bonding offers greater freedom in adjusting the bond pitch, better mechanical stress relief, and potentially higher integration process tolerance.

[0054] This configuration allows the density of the processing units 120 to be no longer limited by the density of the transmitters 110 or receivers 120. For example, if the wiring layer 600 is hybrid-bonded with the first functional layer 200 and the processing circuit layer 100, and the spacing between the transmitters 110 is 4 micrometers, then the spacing between the corresponding processing units 120 in the processing circuit layer 100 bonded to it must also be 4 micrometers. However, when the wiring layer 600 is hybrid-bonded with the first functional layer 200 and simultaneously bonded with the bumps of the processing circuit layer 400, the spacing between the bonding balls can be set to other spacings such as 3 micrometers or 5 micrometers, thus allowing the spacing between the processing units 120 to be 3 micrometers or 5 micrometers, providing greater adaptability in actual products.

[0055] In other embodiments, the wiring layer 600 can be bonded to the first functional layer 200 via bump bonding, and the wiring layer 600 can be bonded to the processing circuit layer 100 via hybrid bonding. Alternatively, the wiring layer 600 can be directly fabricated on the processing circuit layer 100 by etching and filling vias, and the wiring layer 600 can be bonded to the first functional layer 200 via hybrid bonding or bump bonding. Or, the wiring layer 600 can be directly fabricated on the first functional layer 200 by etching and filling vias, and then bonded to the processing circuit layer 100 via bump bonding or hybrid bonding. The connection method between the wiring layer 600 and the first functional layer 200, and the connection method between the wiring layer 600 and the processing circuit layer 100, is not limited and can be selected according to requirements.

[0056] Additionally, it should be noted that in practical applications, bonding leads 102 are arranged in both the processing circuit layer 100 and the first functional layer 200. The bonding leads 102 are used to achieve electrical connection between the transmitter 110 or receiver 120 and the processing circuit layer 100. The bonding leads 102 are typically presented as metal-filled vias and interconnect redistribution layers pre-fabricated within each layer. When rebonding connections are fabricated between layers, metallized contact areas, i.e., bonding pads (not shown in the figure), are also formed on the bonding leads 102 on the surface of the layer structure for electrical interconnection with other layer devices.

[0057] Please return Figure 1 In one embodiment, the optical communication chip further includes an optical coupling layer 500. The optical coupling layer 500 is stacked on the second functional layer 400. The optical coupling layer 500 serves as the optical interface of the optical communication chip and is used to perform optical shaping processing on the input or output optical signals. That is, the output angle or input angle of the optical communication chip can be adjusted and controlled through the optical coupling layer 500 to obtain a beam with a specific shape and divergence angle.

[0058] In practical applications, when using this optical communication chip to transmit information, the light emitted by the transmitter 110 passes through the second dielectric layer 410 on the second functional layer 400 and is transmitted to the optical coupling layer 500. The optical coupling layer 500 performs optical shaping on the light signal before forming an output light signal and outputting it. Similarly, when using the optical communication chip to receive information, the light is first transmitted to the optical coupling layer 500, and the optical coupling layer 500 performs optical shaping on the received light to form an input light signal before transmitting it to the receiver 120.

[0059] By configuring the optical coupling layer 500, on the one hand, for the transmitter 110, the optical coupling layer can collimate or focus the emitted divergent light, thereby controlling the divergence angle of the emitted beam and improving the coupling efficiency of optical power. That is, under the same driving current, the light emitted by the optical communication chip with the optical coupling layer 500 will be brighter, which is beneficial for the transmitter 110 to achieve sufficient light emission brightness with a smaller driving current, thus helping to reduce the power consumption of the transmitter 110. At the same time, the beam divergence angle is controlled within a certain angle, which can expand the alignment tolerance between the optical communication chip and the optical signal transmission channel or medium during subsequent optical communication. On the other hand, for the receiver 120, the optical coupling layer 500 can collect incident light over a wider angle range and converge it onto the photosensitive area of ​​the receiver 120, thereby increasing the received optical power, improving the receiving sensitivity and communication distance, and facilitating the formation of a key interface layer for efficient and stable optical path coupling between the optical communication chip and the optical transmission channel.

[0060] It is understandable that the optical coupling layer 500 only needs to satisfy the requirement of achieving beam shaping. Therefore, in one embodiment, an optical lens array 510 can be provided in the optical coupling layer 500, wherein the optical lenses correspond one-to-one with the transmitter 110 and the receiver 120, that is, the number of optical lenses is the sum of the number of transmitters 110 and receivers 120. When the transmitters 110 and receivers 120 are misaligned, a micro-optical lens dedicated to optical path control is provided above each independent transmitter 110 or receiver 120. When the transmitters 110 and receivers 120 are perpendicularly arranged, a micro-optical lens dedicated to optical path control is provided in the optical path transmission direction corresponding to the transmitter 110 or receiver 120. In other embodiments, the optical coupling layer 500 can also be directly fabricated using photonic crystals (PhC) material without the need for an optical lens array. In this case, precise beam control can be achieved through the design of nanostructures. In another embodiment, high refractive index materials such as TiO2, Si3N4, and HfO2 can be processed using deep ultraviolet lithography, nanoimprint lithography, and laser three-dimensional nanoprinting to form an optical coupling layer 500 with a metasurface structure. This allows for precise control of the light beam by arranging nanopillars, nanopores, and other structures in a two-dimensional plane.

[0061] It is also understood that the connection method between the optical coupling layer 500 and the second functional layer 400 is not limited. For example, in one embodiment, the optical coupling layer 500 can be fabricated as a monolithic layer and then connected to the second functional layer 400 by bonding or low-temperature bonding. Alternatively, the optical coupling layer 500 can be fabricated directly on the pre-fabricated second functional layer 400 using processes such as photoresist thermal reflow, grayscale photolithography, nanoimprint lithography, or inkjet printing.

[0062] It should be noted that the features described in the foregoing embodiments in this application can be selectively combined. For example, an optical communication chip may simultaneously include a processing circuit layer 100, a wiring layer 600, a first functional layer 200, an optical functional layer 300, a second functional layer 400, and an optical coupling layer 500, wherein the first device and the second device are aligned, and an optical lens array is formed within the optical coupling layer 500. Alternatively, an optical communication chip may simultaneously include a processing circuit layer 100, a first functional layer 200, an optical functional layer 300, a second functional layer 400, and an optical coupling layer 500, wherein the first device and the second device are aligned, and the optical coupling layer 500 does not contain an optical lens array. Alternatively, other functional layers may be included between the first functional layer 200 and the second functional layer 400. While exhaustive examples of feasible implementations are not provided here, the scheme of integrating the transmitter 110 and the receiver 120 through a vertically stacked integration method by introducing the optical functional layer 300 falls within the scope of protection of this application.

[0063] Please continue reading. Figure 4 This application also provides a method for fabricating an optical communication chip. This method establishes a process path for fabricating optical communication chips by first modularly fabricating and then integrating them, which can efficiently, simply, and reliably achieve the fabrication of the aforementioned vertically stacked optical communication chips.

[0064] Please see Figure 4 In one embodiment, the method for fabricating an optical communication chip specifically includes the following steps: S1. Provide a first functional layer or a first wafer containing at least two first functional layers, wherein the first functional layer includes a plurality of first devices; provide a second functional layer or a second wafer containing at least two second functional layers, wherein the second functional layer includes a plurality of second devices; provide a processing circuit layer or a third wafer containing at least two processing circuit layers; provide an optical functional layer or a fourth wafer containing at least two optical functional layers.

[0065] S2. Connect the first functional layer or the first wafer, the second functional layer or the second wafer, the processing circuit layer or the third wafer, and the optical functional layer or the fourth wafer so that the first device and the second device are both connected to the processing circuit layer and the first functional layer is located on the side closer to the processing circuit layer, and the optical functional layer is located between the first functional layer and the second functional layer. The first device and the second device are respectively selected from one or the other of the transmitter and the receiver.

[0066] It is understood that "providing the first functional layer or the first wafer, the second functional layer or the second wafer, the processing circuit layer or the third wafer, and the optical functional layer or the fourth wafer" in step S1 means that the first functional layer or the first wafer, the second functional layer or the second wafer, the processing circuit layer or the third wafer, and the optical functional layer or the fourth wafer can be obtained by self-preparation or by purchase.

[0067] "Connecting the first functional layer or the first wafer, the second functional layer or the second wafer, the processing circuit layer or the third wafer, and the optical functional layer or the fourth wafer" refers to forming a reliable mechanical and electrical connection between the first functional layer or the first wafer, the second functional layer or the second wafer, the processing circuit layer or the third wafer, and the optical functional layer or the fourth wafer through physical or chemical methods.

[0068] The specific steps of the connection processing in step S2 may include, but are not limited to, the following: A1. Bond the first wafer, the second wafer, the third wafer, and the fourth wafer, so that the four wafers are stacked in the order of the third wafer, the first wafer, the fourth wafer, and the second wafer, and then cut the bonded structure to obtain an optical communication chip.

[0069] A2. Bond the first wafer, the second wafer, and the fourth wafer, stacking them in the order of the first wafer, the fourth wafer, and the second wafer. Cut the bonded structure to obtain the first intermediate chip. Then bond the first intermediate chip to the processing circuit layer to obtain the optical communication chip.

[0070] A3. Bond the first wafer, the fourth wafer, the second wafer and the processing circuit layer, and then cut the bonded structure to obtain the optical communication chip. A4. Directly bond the first functional layer, the second functional layer, the optical functional layer, and the processing circuit layer to obtain an optical communication chip.

[0071] In essence, an optical communication chip is an integrated chip, where each layer can be fabricated, sold, and assembled as an independent chip. During the integration of these layers to form the optical communication chip, the first functional layer, second functional layer, optical functional layer, and driving circuit layer can be directly connected as chips via chip-to-chip bonding (Scheme A4). Alternatively, they can be connected as wafers via wafer-to-wafer bonding and then diced to form the final integrated chip (Scheme A1). Or, they can be partially chip-based and partially wafer-based, connected via chip-to-wafer bonding and then diced to form the final integrated chip (Schemes A2 and A3). This design breaks down the complex heterogeneous integration task into two stages: pre-fabrication of functional units independently and subsequent selective integration and assembly. This allows each functional layer (device layer, optical layer, circuit layer) to be independently and optimally manufactured on its respective wafer using processes best suited to its material properties and performance requirements. For example, CMOS processing circuits can be fabricated on silicon wafers, while light-emitting or detector arrays can be fabricated on compound semiconductor (such as GaN-on-Si or InP) wafers. The subsequent bonding operation aims to establish a stable mechanical connection and electrical interconnection between the corresponding interfaces of the two wafers under low or medium temperature conditions through surface activation, pressure, and other methods. This overcomes the strict limitations of traditional heterogeneous integration on processing conditions, thereby improving the fabrication efficiency and production capacity of optical communication chips while ensuring optimal chip quality.

[0072] Understandably, there are multiple options for the specific bonding method of "bonding the first, second, third, and fourth wafers." For example, the second and fourth wafers can be bonded first, followed by the first and third wafers in sequence; or the first and third wafers can be bonded first, followed by the fourth and second wafers in sequence; or the four wafers can be arranged in the order of third, first, fourth, and second wafers and then bonded all at once. The multilayer stacking is not limited to simultaneous one-time bonding, but allows for three independent wafer-to-wafer bonding operations. The second and subsequent bonding operations involve a wafer to a wafer pair that has already completed its first bonding. This allows for individual optimization of parameters (such as temperature, pressure, and surface pretreatment) for each bonding process step, taking into account differences in thermal expansion coefficients between different material combinations (such as compound semiconductors and silicon), surface flatness requirements, and bonding alignment accuracy. This helps alleviate the accumulated process stress and alignment errors caused by one-time multilayer bonding, improving the bonding yield and long-term reliability of the final stacked structure. The same applies to the bonding order of "bonding the first functional layer, the second functional layer, the optical functional layer, and the driving circuit layer".

[0073] It is also understood that in other embodiments, if the optical communication chip further includes an optical coupling layer, then the corresponding step S1 further includes the step of providing an optical coupling layer or an optical coupling wafer containing at least two optical coupling layers, and step S2 further includes the step of connecting the optical coupling layer or optical coupling wafer and the second functional layer or second wafer to make the optical coupling layer stacked on the second functional layer.

[0074] Similarly, the optical coupling layer can be fabricated in-house or purchased. It can be connected to the second functional layer or the second wafer in a chip-to-chip, chip-to-wafer, or wafer-to-wafer manner. Alternatively, the optical coupling layer can be directly fabricated on the second functional layer. The steps for stacking the optical coupling layer on the second functional layer include, but are not limited to, the following: B1, Directly bonded optical coupling layer and second functional layer; B2. Bond the optically coupled wafer and the second wafer, and cut the bonded structure. B3. An optical coupling layer is directly fabricated on the second functional layer using processes such as nanoimprinting, inkjet printing, and grayscale photolithography. B4. After preparing an optically coupled wafer on a second wafer using processes such as nanoimprinting, inkjet printing, and grayscale lithography, the resulting composite wafer is then diced.

[0075] Understandably, the second wafer and the optocoupler wafer can be bonded together via adhesive bonding or low-temperature bonding. The timing of the connection between the optocoupler layer and the second functional layer is not restricted. For example, the optocoupler layer can be formed on the second wafer first, and then the second wafer can be bonded to the fourth wafer; alternatively, the second wafer can be bonded to the fourth wafer first, then the optocoupler layer can be formed before bonding the remaining two wafers; or, the first, second, third, and fourth wafers can all be bonded and diced to form an intermediate chip, and then the optocoupler layer can be formed directly on the intermediate chip.

[0076] In other embodiments, if the optical communication chip also includes a wiring layer, then step S1 further includes the step of providing a wiring layer or a carrier wafer containing at least two wiring layers, and step S2 further includes the step of connecting the wiring layer or the carrier wafer, the first functional layer or the first wafer, and the processing circuit layer or the third wafer so that the wiring layer is located between the first functional layer and the processing circuit layer.

[0077] Similarly, the wiring layer can be fabricated in-house or purchased. The wiring layer can connect to the first functional layer and the processing circuit layer in a chip-to-chip, chip-to-wafer, or wafer-to-wafer manner. Alternatively, the wiring layer can be fabricated directly on the first functional layer or the processing circuit layer. The steps of stacking the wiring layer between the first functional layer and the processing circuit layer include, but are not limited to, the following: C1. Bond the first wafer, the carrier wafer, and the third wafer, so that the three wafers are stacked in the order of the third wafer, the carrier wafer, and the first wafer, and then cut the bonded structure. C2. Bond the first wafer and the carrier wafer, and cut the bonded structure to obtain the second intermediate chip. Then bond the second intermediate chip to the processing circuit layer. C3. Bond the carrier wafer and the third wafer, and cut the bonded structure to obtain the third intermediate chip. Then bond the third intermediate chip to the first functional layer. C4, bonding the first functional layer, routing layer and processing circuit layer; C5. The carrier wafer is prepared directly on the first wafer by etching and filling holes, and the wiring layer is cut to form a trace layer. Then the processing circuit layer is bonded to the trace layer.

[0078] Understandably, the timing of the formation of the wiring layer is not restricted. For example, a carrier wafer can be formed on the first wafer first, and then the carrier wafer can be bonded to the third wafer. Alternatively, the first wafer and the fourth wafer can be bonded first, and then the carrier wafer can be formed on the first wafer. Or, the first wafer and the fourth wafer can be bonded first, while the carrier wafer is grown on the third wafer at the same time, and finally the first wafer and the carrier wafer are bonded together.

[0079] This fabrication method allows for secondary layout of optical communication chips using traces on the carrier wafer. It also allows the formation process of optical communication chips to be distributed among multiple manufacturers, thereby reducing the processing requirements for some of them and helping to reduce production costs.

[0080] This application also provides an optical communication terminal, which includes the aforementioned optical communication chip. The terminal uses the chip as its core photoelectric conversion and processing unit to construct an independent device or module with complete optical signal transmission, reception, and processing functions. In this terminal, the chip's processing circuit layer is responsible for executing communication protocol processing, signal encoding / decoding, and drive control functions; its vertically integrated transmitter and receiver array can be directly or through an optical coupling layer connected to an optical window or lens on the terminal casing to achieve coupling with an external free-space optical link; simultaneously, other necessary components of the terminal, such as a power management module, external power interfaces (e.g., high-speed data interfaces), mechanical structures, and auxiliary control circuits, are all configured and connected around the chip. This terminal design enables all the technological advantages of the aforementioned high-density, miniaturized chip to be realized at the device level, specifically manifested in the reduction of the overall terminal size, optimization of power consumption, and improvement of communication bandwidth and reliability.

[0081] like Figure 5 As shown, this application also provides an optical communication system. The optical communication system includes a first communication terminal, an optical transmission channel, and a second communication terminal.

[0082] The first and second communication terminals both include the transceiver integrated optical communication chip provided in this application. That is, the optical communication system includes at least two communication terminals. The optical transmission channel is a specific optical signal transmission channel or medium, such as free space or optical fiber. In other words, as long as the optical communication transmitter and the optical communication receiver can transmit light through the specific optical signal transmission channel or medium, communication can be achieved.

[0083] The core feature of this system architecture is that each terminal utilizes the arrayed transmission and reception capabilities of its internal chips to transmit full-duplex or half-duplex data via visible light or other specific wavelengths of light through a specific optical signal transmission channel or medium. In this scenario, the transmitter array (such as a micro-LED array) in the terminal chip can be used to transmit modulated optical signals in a specific direction, while its receiver array (such as a photodetector array) can detect and decode optical signals from other terminals in real time, thereby achieving low-latency, high-density information exchange between devices.

[0084] The number of optical communication chips used in the first and second communication terminals is unlimited and can be adjusted according to the actual communication needs and the size of the optical communication chips. For example, it can be composed of only one chip or multiple chips spliced ​​together.

[0085] The optical communication system proposed in this application can be applied to vehicle-to-vehicle (V2V) communication / vehicle-to-infrastructure (V2I) systems in vehicle networks and intelligent transportation systems. For example, optical communication chips can be placed in the light-emitting positions of vehicles and traffic facilities such as front and rear lights, traffic lights, and streetlights. This allows the optical communication chips to provide lighting and display functions while also acting as communication nodes to transmit information, facilitating the provision of vehicle location, speed, and road condition information, improving traffic safety and efficiency, and achieving efficient resource utilization. Alternatively, the visible light communication system provided in this application can also be used for network data interconnection in office environments. For instance, visible light communication chips can be placed in two visible light communication terminals, which are interconnected via optical fiber. Information-carrying light is transmitted through the optical fiber, and information conversion and processing are performed in the visible light communication terminals, thereby achieving high-density, high-capacity optical communication at the network layer.

[0086] The above is only one specific implementation of this application, and any other improvements made based on the concept of this application shall be considered within the scope of protection of this application.

Claims

1. An optical communication functional device layer, characterized in that, It includes a first functional layer, an optical functional layer, and a second functional layer that are stacked together; The first functional layer includes a transmitter, and the second functional layer includes a receiver; or, the first functional layer includes a receiver, and the second functional layer includes a transmitter. The optical functional layer is located between the first functional layer and the second functional layer. The optical functional layer is used to change the transmission direction of the optical signal so that the light emitted or received by the device in the first functional layer does not pass through the device in the second functional layer. The transmitter is used to convert electrical signals into optical signals, and the receiver is used to convert optical signals into electrical signals.

2. The optical communication functional device layer according to claim 1, characterized in that, The transmitters are arrayed in the first functional layer, and the receivers are arrayed in the second functional layer; or, the transmitters are arrayed in the second functional layer, and the receivers are arrayed in the first functional layer.

3. An optical communication chip, characterized in that, It includes a stacked processing circuit layer and an optical communication functional device layer as described in any one of claims 1-2; The first functional layer is located on the side close to the processing circuit layer; both the transmitter and the receiver are electrically connected to the processing circuit layer, which is used to process the input or output electrical signals.

4. The optical communication chip according to claim 3, characterized in that, The optical communication chip also includes an optical coupling layer, which is stacked on the second functional layer and is used to perform optical shaping processing on the input or output optical signals.

5. The optical communication chip according to claim 4, characterized in that, An optical lens array is provided within the optical coupling layer, wherein the optical lenses are configured one-to-one with the transmitter and the receiver. Alternatively, the optical coupling layer may comprise a photonic crystal material or have a metasurface structure.

6. The optical communication chip according to any one of claims 3-5, characterized in that, The optical communication chip further includes a wiring layer, which is located between the processing circuit layer and the first functional layer. The wiring layer and the processing circuit layer are connected in a manner that is the same or different.

7. The optical communication chip according to claim 6, characterized in that, The wiring layer is hybrid-bonded to the first functional layer, and the wiring layer is bump-bonded to the processing circuit layer; Alternatively, the wiring layer and the first functional layer are mixed-bonded, and the wiring layer and the processing circuit layer are mixed-bonded; Alternatively, the routing layer is bonded to the first functional layer via bump bonding, and the routing layer is bonded to the processing circuit layer via hybrid bonding. Alternatively, the wiring layer is directly fabricated on the first functional layer, and the wiring layer and the processing circuit layer are bonded by bump bonding or hybrid bonding; Alternatively, the wiring layer may be directly fabricated on the processing circuit layer, and the wiring layer may be bonded to the first functional layer via bump bonding or hybrid bonding.

8. A method for fabricating an optical communication chip, characterized in that, Includes the following steps: A first wafer is provided, which includes a first functional layer or at least two first functional layers, wherein the first functional layer includes a plurality of first devices; Provide a second functional layer or a second wafer containing at least two second functional layers, wherein the second functional layer includes a plurality of second devices; Provide a processing circuit layer or a third wafer containing at least two processing circuit layers; Provides an optical functional layer or a fourth wafer containing at least two optical functional layers; The first functional layer or first wafer, the second functional layer or second wafer, the processing circuit layer or third wafer, and the optical functional layer or fourth wafer are connected to make the first device and the second device both connected to the processing circuit layer, with the first functional layer located on the side closer to the processing circuit layer, and the optical functional layer located between the first functional layer and the second functional layer. The first device and the second device are respectively selected from one or the other of a transmitter and a receiver.

9. The preparation method according to claim 8, characterized in that, The step of connecting the first functional layer or first wafer, the second functional layer or second wafer, the processing circuit layer or third wafer, and the optical functional layer or fourth wafer specifically includes the following: The first wafer, the second wafer, the third wafer, and the fourth wafer are bonded together so that the four wafers are stacked in the order of the third wafer, the first wafer, the fourth wafer, and the second wafer, and the bonded structure is then cut. Alternatively, the first wafer, the second wafer, and the fourth wafer are bonded together, such that the three wafers are stacked in the order of the first wafer, the fourth wafer, and the second wafer, and the bonded structure is cut to obtain the first intermediate chip, and then the first intermediate chip is bonded to the processing circuit layer. Alternatively, the first functional layer, the second functional layer, the optical functional layer, and the processing circuit layer can be bonded together.

10. The preparation method according to claim 8, characterized in that, The preparation method further includes the following steps: The step of providing an optical coupling layer or an optical coupling wafer containing at least two optical coupling layers, and connecting the optical coupling layer or optical coupling wafer and the second functional layer or second wafer to stack the optical coupling layer on the second functional layer.

11. The preparation method according to claim 10, characterized in that, The step of connecting the optical coupling layer or optical coupling wafer and the second functional layer or second wafer specifically includes the following: Bonding the optical coupling layer to the second functional layer; Alternatively, the optically coupled wafer can be bonded to the second wafer, and the bonded structure can be cut. Alternatively, an optical coupling layer can be fabricated directly on the second functional layer; Alternatively, an optically coupled wafer can be fabricated directly on the second wafer, and the structure formed after the optically coupled wafer is cut.

12. The preparation method according to claim 8, characterized in that, The preparation method further includes the following steps: The step of providing a wiring layer or a carrier wafer containing at least two wiring layers, and connecting the wiring layer or the carrier wafer, a first functional layer or a first wafer, and a processing circuit layer or a third wafer so that the wiring layer is located between the first functional layer and the processing circuit layer.

13. The preparation method according to claim 12, characterized in that, The step of connecting the wiring layer or the carrier wafer, the first functional layer or the first wafer, and the processing circuit layer or the third wafer specifically includes the following: The first wafer, the carrier wafer, and the third wafer are bonded together so that the three wafers are stacked in the order of the third wafer, the carrier wafer, and the first wafer, and the bonded structure is then cut. Alternatively, the first wafer and the carrier wafer are bonded together, and the bonded structure is cut to obtain the second intermediate chip, which is then bonded to the processing circuit layer. Alternatively, the carrier wafer and the third wafer are bonded together, and the bonded structure is cut to obtain the third intermediate chip, and then the third intermediate chip is bonded to the first functional layer. Alternatively, the first functional layer, the wiring layer, and the processing circuit layer can be bonded together. Alternatively, a carrier wafer can be fabricated directly on the first wafer and cut to form a wiring layer, and then the processing circuit layer can be bonded to the wiring layer.

14. An optical communication terminal, characterized in that, Includes the optical communication chip as described in any one of claims 3-7.

15. An optical communication system, characterized in that, It includes at least two optical communication terminals as described in claim 14.

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