Optical communication module and manufacturing method

Abstract

The application provides an optical communication module and a preparation method. The sensor comprises a circuit board, an optical fiber and at least two optical transceiver modules connected with the circuit board. The optical transceiver module comprises a semiconductor substrate, a plurality of light sensing units and a light emitting element. The light emitting element of one optical transceiver module is optically coupled with the light sensing unit of another optical transceiver module through the optical fiber. The light sensing unit comprises a first doped layer, an intrinsic semiconductor layer and a second doped layer vertically arranged on the semiconductor substrate. The preparation steps are as follows: the first doped layer and the second doped layer are vertically injected on the semiconductor substrate at intervals to form the light sensing unit; then the light emitting element is bonded on the semiconductor substrate; and then the electric connection layer with the gate structure, the dielectric layer structure and the metal trace is deposited and etched to connect the gate structure and the metal trace with the two doped layers, respectively, to obtain the optical transceiver module. The operation is simple, the mass production is easy, and the finished product can improve the photoelectric conversion efficiency.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, and in particular to an optical communication module and its manufacturing method. Background Technology

[0002] With the rapid development of high-speed optical communication systems, increasingly higher demands are being placed on the photoelectric conversion efficiency, response speed, and integration density of optical receiving devices. PIN photodiodes (PIN-PDs) are widely used in photoelectric conversion at optical communication receivers due to their advantages such as fast response speed, low dark current, and high quantum efficiency. However, in existing integrated architectures, photoelectric conversion efficiency is relatively low due to structural limitations. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide an optical communication module and a method for preparing it that can improve photoelectric conversion efficiency.

[0004] The present invention provides an optical communication module, comprising: a circuit board, an optical fiber, and at least two optical transceiver modules. The optical transceiver modules are connected to the circuit board. Each optical transceiver module includes a semiconductor substrate, a plurality of photosensitive units disposed on the semiconductor substrate, and a light-emitting element. The light-emitting element of one optical transceiver module is optically coupled to the photosensitive unit of another optical transceiver module through the optical fiber. The photosensitive unit includes a first doped layer, an intrinsic semiconductor layer, and a second doped layer arranged vertically on a semiconductor substrate.

[0005] Optical fibers are used to enable optical signal transmission between different optical transceiver modules. The intrinsic semiconductor layer of the photosensitive unit is vertically arranged on the semiconductor substrate, facing the direction of incident light, which shortens the transmission path of the optical signal, reduces signal loss, and improves the light sensitivity of the intrinsic semiconductor layer, thereby improving the photoelectric conversion efficiency.

[0006] This invention also provides a method for manufacturing an optical communication module, comprising the following steps: A photosensitive unit is formed by implanting a first doped layer and a second doped layer perpendicular to the semiconductor substrate at intervals on the semiconductor substrate. A light-emitting element is bonded onto the semiconductor substrate; An electrical connection layer having a gate structure, a dielectric layer structure, and metal traces is deposited and etched on the semiconductor substrate; wherein the gate structure, the metal traces, the first doped layer, and the second doped layer are connected to form an optical transceiver module; The light-emitting element of one of the optical transceiver modules is optically coupled to the photosensitive unit of another optical transceiver module via an optical fiber. The fabrication method is simple to operate and easy to mass-produce. Attached Figure Description

[0007] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 A top view of the optical communication module provided in this embodiment (optical fiber omitted).

[0009] Figure 2 This embodiment provides a schematic diagram illustrating the working principle of the optical communication module.

[0010] Figure 3 This is a cross-sectional view of the optical transceiver module provided in this embodiment.

[0011] Figure 4 This is a cross-sectional view of the optical communication module provided in this embodiment.

[0012] Figure 5a This is a flowchart illustrating the fabrication method of the optical communication module provided in this embodiment.

[0013] Figure 5b This is a flowchart illustrating the fabrication method of the optical communication module provided in this embodiment.

[0014] Figure 5c This is a flowchart illustrating the fabrication method of the optical communication module provided in this embodiment.

[0015] Figure 5d This is a flowchart illustrating the fabrication method of the optical communication module provided in this embodiment.

[0016] Figure 5e This is a flowchart illustrating the fabrication method of the optical communication module provided in this embodiment.

[0017] Figure 5f This is a flowchart illustrating the fabrication method of the optical communication module provided in this embodiment.

[0018] Figure 5g This is a flowchart illustrating the fabrication method of the optical communication module provided in this embodiment.

[0019] Figure 5h This is a flowchart illustrating the fabrication method of the optical communication module provided in this embodiment.

[0020] Figure 5i This is a flowchart illustrating the fabrication method of the optical communication module provided in this embodiment.

[0021] Figure 5j This is a flowchart illustrating the fabrication method of the optical communication module provided in this embodiment.

[0022] Figure 5k This is a flowchart illustrating the fabrication method of the optical communication module provided in this embodiment.

[0023] Figure 5l This is a flowchart illustrating the fabrication method of the optical communication module provided in this embodiment.

[0024] Figure 6a This is a cross-sectional view of the optical transceiver structure in this embodiment.

[0025] Figure 6b This is a cross-sectional view of the optical transceiver structure in this embodiment.

[0026] Figure 6c This is a cross-sectional view of the optical transceiver structure in this embodiment.

[0027] Figure 6d This is a cross-sectional view of the optical transceiver structure in this embodiment.

[0028] Figure 7a This is a cross-sectional view of the photosensitive unit in this embodiment.

[0029] Figure 7b This is a cross-sectional view of the photosensitive unit in this embodiment. Detailed Implementation

[0030] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. Based on the description of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0031] In the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0032] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0033] The terms “first,” “second,” “third,” etc., are used merely to distinguish elements with similar properties, not to indicate or imply relative importance or a specific order.

[0034] The terms “include,” “comprising,” or any other variation thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0035] Reference Figures 1 to 4 An optical communication module includes: a circuit board 1, an optical fiber 6, and at least two optical transceiver modules 10. The optical transceiver modules 10 are connected to the circuit board 1. Each optical transceiver module 10 includes an optical transceiver structure and includes a semiconductor substrate 41, a plurality of photosensitive units 5 disposed on the semiconductor substrate 41, and a light-emitting element 42. The light-emitting element 42 of one optical transceiver module 10 is optically coupled to the photosensitive unit 5 of another optical transceiver module 10 through the optical fiber 6. The optical signal emitted by one light-emitting element 42 is transmitted along the optical fiber 6 to the photosensitive unit 5 of the other optical transceiver module 10. After receiving the optical signal, the photosensitive unit 5 converts the optical signal into an electrical signal and then transmits the electrical signal to the next processing module.

[0036] Reference Figure 3 and Figure 6a The photosensitive unit 5 includes a first doped layer 51, an intrinsic semiconductor layer 52, and a second doped layer 53 arranged vertically on the semiconductor substrate 41. The intrinsic semiconductor layer 52 faces the incident light direction and is not blocked by the planar first doped layer 51 or the second doped layer 53. It can respond quickly to optical signals, thereby increasing the light-receiving area of ​​the optical transceiver structure, shortening the transmission path of the optical signal, reducing signal loss, and improving the light sensitivity of the intrinsic semiconductor layer 52.

[0037] Specifically, the semiconductor substrate 41 is composed of semiconductor materials such as silicon, germanium, silicon-germanium, gallium arsenide, and indium phosphide. The first doped layer 51 is an N+ doped layer, comprising a high concentration of a suitable n-type dopant, such as arsenic (As) and / or phosphorus (P); the second doped layer 51 is a P+ doped layer, comprising a high concentration of a suitable p-type dopant, such as boron (B). In optional embodiments, the two doping types can be interchanged, i.e., the second doped layer 51 is an N+ doped layer and the first doped layer 51 is a P+ doped layer. The intrinsic semiconductor layer 52 can be a pure / neutral semiconductor material, i.e., the intrinsic semiconductor layer 52 may not contain any dopant. In another embodiment, compared to the first doped layer 51 and the second doped layer 53, the intrinsic semiconductor layer 52 may include a relatively low concentration of dopant.

[0038] In this embodiment, semiconductor substrate 41 refers to the original substrate silicon wafer (N+ / P+ silicon substrate, InP substrate), and semiconductor substrate 41 can also refer to the structure of the original substrate silicon wafer combined with the epitaxial layer.

[0039] Reference Figure 2 , Figure 6b and Figure 6c To further improve the sensitivity of the intrinsic semiconductor layer 52 to light, the optical transceiver module 10 also includes a first refractive layer 100 with a microlens array 101 and a second refractive layer 200 with a primary lens 201. The first refractive layer 100 and the second refractive layer 200 are sequentially stacked on the photosensitive unit 5. When the photosensitive unit 5 is illuminated, the light first enters the primary lens 201, is refracted and focused by the primary lens 201, and then enters the microlens array 101. The microlens array 101 then refracts the light to the corresponding photosensitive unit 5. Specifically, the microlens array 101 consists of multiple secondary microlenses 55. Each secondary microlens 55 covers one photosensitive unit 5, and the secondary microlenses 55 specifically enhance the incident light intensity of each photosensitive unit 5, further improving the response speed of the optical transceiver structure to optical signals.

[0040] In optical communication module applications, optical fiber 6 typically contains multiple fiber strands. In this case, adjacent fiber strands may have one in operation and another in a stopped state. The primary lens 201 corresponding to the operational fiber 6 has a chance to refract the optical signal into the microlens array 101 in the adjacent area, causing crosstalk. To solve this technical problem, the first refractive layer 100 also includes a light-blocking member 102 disposed between adjacent microlens arrays 101. The light-blocking member 102 is used to prevent the light refracted by the primary lens 201 from diverging into the adjacent photosensitive unit 5, thus preventing crosstalk.

[0041] Specifically, the light-blocking component 102 can be made of opaque tungsten nitride, titanium nitride, tantalum nitride, or zirconium nitride.

[0042] In some embodiments, the optical transceiver module 10 further includes an isolation structure 45 disposed on a semiconductor substrate 41, the isolation structure 45 being disposed between adjacent photosensitive units 5, and a light-blocking member 102 being partially disposed within the semiconductor substrate 41. When light is refracted from the primary lens 201 into the second refractive layer 200, the light-blocking member 102 can reduce the refraction of light towards adjacent photosensitive units 5 within the second refractive layer 200, further reducing crosstalk. Optionally, referring to... Figure 6b An electrical isolation structure 45 is provided on the first surface 411 and extends to the second surface 412. Optionally, refer to... Figure 6c An electrical isolation structure 45 is formed on the second surface 412 and extends to the first surface 411, and the electrical isolation structure 45 penetrates the semiconductor substrate 41. Optionally, referring to... Figure 6dThe electrical isolation structure 45 includes a deep trench isolation structure 451 and a shallow trench isolation structure 452. The shallow trench isolation structure 452 is formed on the first surface 411 and extends to the second surface 412. The deep trench isolation structure 451 and the shallow trench isolation structure 452 are connected.

[0043] Specifically, more specifically, the primary lens 201 and the secondary microlens 55 are convex lenses.

[0044] Reference Figure 7a and Figure 7b The optical fiber has a circular cross-section. The light signal it transmits is refracted by a convex lens and then shines into the photosensitive unit 5. To further improve the response speed of the photosensitive unit 5, its cross-section can be designed as a ring. There are multiple intrinsic semiconductor layers 52, which are separated by a first doped layer 51 or a second doped layer 53. Because the secondary microlens 55 is a convex lens, the light intensity at the center of the ring-shaped photosensitive unit 5 is the greatest, and the light intensity gradually decreases towards the outer periphery of the ring. Therefore, the sensitivity of each intrinsic semiconductor layer 52 to light is inconsistent. To solve the above technical problem, the widths W1, W2, and W3 of the intrinsic semiconductor layers 52 increase sequentially from the center to the outer periphery of the ring structure. There are multiple first doped layers 51 and intrinsic semiconductor layers 52, and the doping concentration of the first doped layer 51 and intrinsic semiconductor layers 52 increases sequentially.

[0045] The intrinsic semiconductor layer 52 gradually widens, which increases the incident area of ​​the intrinsic semiconductor layer 52. In order to reduce the difficulty of electron absorption caused by the increased spacing between the adjacent first doped layer 51 and second doped layer 53 due to the increased width of the intrinsic semiconductor layer 52, the doping concentration of the first doped layer 51 and the intrinsic semiconductor layer 52 increases from the center to the outer periphery of the annular structure, which can improve the stability of electron absorption efficiency.

[0046] In some embodiments, the isolation structure 45 is annular, and the photosensitive unit 5 is disposed in the isolation structure 45. The distance W4 between the photosensitive unit 5 and the isolation structure 45 is greater than the width of the intrinsic semiconductor layer 52 to prevent crosstalk between adjacent photosensitive units 5.

[0047] Reference Figure 4Specifically, the optical transceiver module 10 further includes a first substrate 21 and a functional layer 22 connected to the first substrate 21. The semiconductor substrate 41 is connected to the side of the functional layer 22 away from the first substrate 21. The functional layer 22 includes a transmitting module, a receiving module, and a data conversion module connected to the transmitting module and the receiving module, all disposed on the first substrate 21. Specifically, the transmitting module is a TX module (Transmitter), which modulates and converts electrical signals into corresponding optical signals and transmits them outward, transmitting the detection data of the optical communication module to another photosensitive unit 5 in the form of optical signals. The receiving module is an RX module (Receiver), which receives the optical signals transmitted by the light-emitting element 42, restores the optical signals to high-speed serial electrical signals, and sends them to the input of the data conversion module. The data conversion module is a SerDes module, i.e., a serializer / deserializer, which can complete the mutual conversion between parallel data and high-speed serial data, realizing data format adaptation of the high-speed data transceiver link. In this embodiment, the light-emitting element 42 is driven by the transmitting module to emit a light signal modulated by a corresponding electrical signal. After being transmitted via the optical fiber 6 to the photosensitive unit 5 of another optical transceiver module 10, the photosensitive unit 5 converts the received light signal into a weak current electrical signal, which is then transmitted by the receiving module to the data conversion module to complete the signal restoration process.

[0048] In another embodiment, the optical transceiver module 10 further includes a second substrate 23, a functional layer 22 connected to a first substrate 21, and a photosensitive unit 5 disposed on the side of the functional layer 22 away from the first substrate 21. The functional layer 22 includes a transmitting module and a receiving module disposed on the first substrate 21, and the second substrate 23 has a data conversion module connected to the transmitting module and the receiving module. By disposing of the transmitting module, the receiving module, and the data conversion module on two different substrates, the transmitting module, the receiving module, and the data conversion module can be manufactured in separate areas, reducing the processing difficulty of different functional modules on the same substrate.

[0049] Specifically, the optical communication module also includes an interposer layer 7, which is disposed between the circuit board 1 and the optical transceiver module 10, and the circuit board 1 and the optical transceiver module 10 are electrically connected through the interposer layer 7. More specifically, the interposer layer 7 is a silicon dielectric layer. The interposer layer 2 and the optical transceiver module 10 can be interconnected with other chips after being packaged in 2.5D.

[0050] Reference Figure 6aSpecifically, the semiconductor substrate 41 includes a first surface 411 and a second surface 412 disposed opposite to each other. The photosensitive unit 5 is disposed on the first surface 411, and the second surface 412 includes a slot 413 disposed thereon, with the slot 413 located on the opposite side of the photosensitive unit 5. By providing the slot 413, the area corresponding to the photosensitive unit 5 can be thinned from the second surface 412, shortening the transmission distance of incident light to the photosensitive unit 5, reducing light loss during transmission in the semiconductor substrate 41, thereby improving the response speed of photocurrent, which is suitable for high-speed optical communication applications.

[0051] Specifically, a reflective layer 9 can be provided on the area of ​​the second surface 412 other than the slot 413.

[0052] This embodiment also provides a method for preparing the above-mentioned optical communication module, including the following steps: S1. Reference Figure 5a and Figure 5b Prepare a semiconductor substrate 41. Specifically, an N-type single-crystal silicon substrate can be selected. P-type impurities (such as boron) and N-type impurities (such as phosphorus or arsenic) are implanted at intervals on the semiconductor substrate 41 to form a first doped layer 51 and a second doped layer 53 perpendicular to the substrate surface. Annealing is then performed to activate the doped ions.

[0053] Step S2, refer to Figure 5c The optical transceiver module 10 is fabricated by depositing a silicon dioxide dielectric layer on a semiconductor substrate 41 using chemical vapor deposition, depositing polycrystalline silicon material, and fabricating a gate structure and metal traces by photolithography and dry etching. The gate structure, metal traces, first doped layer 51 and second doped layer 53 are connected to form an electrical connection layer 44. Step S2.1, refer to Figure 5d and 5e A first substrate 21 is provided, specifically a silicon wafer. A metal thin film is sputtered onto the first substrate 21, and photoresist is uniformly spin-coated onto the surface of the metal thin film. The substrate is then exposed and developed using a mask, leaving a protective layer corresponding to the circuit pattern on the surface of the metal thin film. Dry etching is used to remove the metal in areas without photoresist coverage by gas etching. Finally, the remaining photoresist is stripped off, forming conductive lines on the first substrate 21. An insulating dielectric is deposited on the conductive lines, and interconnecting vias are etched. Metal is sputtered again to fill the vias and the dielectric layer. The sputtering, etching, and insulating dielectric deposition processes are repeated on the first substrate 21 to form a functional layer 22 with TX and RX modules.

[0054] Reference Figure 5g An electrical connection layer 44 is provided, and on the side of the electrical connection layer 44 facing away from the semiconductor substrate 41, it is wafer-level bonded to the functional layer 22 by means of fusion bonding or thermo-press bonding; specifically, the bonding interface may be selected as silicon oxide or silicon nitride as the bonding medium.

[0055] In some other embodiments, step S2.2 is included: providing a second substrate 23, forming a processing layer with a SerDes module on the second substrate 23, and bonding the processing layer to the first substrate 21.

[0056] Step S2.3, refer to Figure 5h On the semiconductor substrate 41, a deep silicon etching process is used to etch a groove 413 to thin the semiconductor substrate 41 at the photosensitive unit 5 and enhance light transmittance.

[0057] A transparent silicon oxide dielectric layer is deposited in the groove 413 as a substrate, and then a photosensitive polymer is coated on it. After the lens array pattern is defined by photolithography, the photosensitive polymer is melted into hemispherical protrusions by a thermal reflow process to form secondary microlenses 55.

[0058] Silica is deposited in trench 413, and the surface is polished by CMP, ultimately leaving only the silica in the trench as an isolation structure.

[0059] Step S3, refer to Figure 5l The light-emitting element 42 is bonded to the semiconductor substrate 41. The N-type gallium nitride layer of the light-emitting element 42 is etched to expose the N-GaN electrode contact area. Through holes are etched on the light-emitting element 42, and a conductive dielectric is deposited in the through holes. The light-emitting element 42 is connected to the electrical connection layer 44. The photosensitive unit 5 and the light-emitting element 42 are combined to form an optical transceiver module 10.

[0060] On the light-emitting surfaces of the semiconductor substrate 41 and the light-emitting element 42, silicon oxide, silicon nitride, or aluminum oxide are deposited using chemical vapor deposition or atomic layer deposition processes to form a protective layer 8.

[0061] Step S3.1: A second substrate 23, which is a silicon wafer, is provided. A metal thin film is sputtered onto the second substrate 23. Photoresist is uniformly spin-coated onto the surface of the metal thin film. The substrate is exposed and developed using a mask, leaving a protective layer of photoresist corresponding to the circuit pattern on the surface of the metal thin film. Dry etching is used to remove the metal in the areas without photoresist coverage by gas etching. Finally, the remaining photoresist is stripped off. A SerDes module is formed on the second substrate 23, and the SerDes module is an independent chip. It should be noted that steps S3.1 and S2.2 are selective.

[0062] Step S3.2, refer to Figure 4 Specifically, it also includes the step of: providing an interposer 7, and bonding the functional layer 22, the electrical connection layer 44, and the semiconductor substrate 41 together onto the interposer 7.

[0063] Specifically, the process also includes the steps of encapsulating a functional layer 22, an electrical connection layer 44, a semiconductor substrate 41, and an interposer layer 7. The SerDes module, which is an independent chip, is connected in the interposer layer 7, and the functional layer 22, the electrical connection layer 44, the semiconductor substrate 41, and the SerDes module are connected through the interposer layer 7.

[0064] Specifically, it also includes the step of flip-chip soldering the interposer layer 7 onto the circuit board 1.

[0065] Step S4: Connect the light-emitting element 42 of one optical transceiver module 10 to the photosensitive unit 5 of another optical transceiver module 10 via optical fiber 6 to form an optical communication module.

[0066] The method for fabricating the optical communication module provided in this embodiment is simple to operate and easy to mass-produce.

[0067] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0068] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. An optical communication module, characterized in that, include: The circuit board (1), the optical fiber (6), and at least two optical transceiver modules (10) are connected to the circuit board (1). Each optical transceiver module (10) includes a semiconductor substrate (41), a plurality of photosensitive units (5) disposed on the semiconductor substrate (41), and a light-emitting element (42). The light-emitting element (42) of one optical transceiver module (10) is optically coupled to the photosensitive unit (5) of another optical transceiver module (10) through the optical fiber (6). The photosensitive unit (5) includes a first doped layer (51), an intrinsic semiconductor layer (52), and a second doped layer (53) arranged vertically on a semiconductor substrate (41).

2. The optical communication module as described in claim 1, characterized in that: The optical transceiver module (10) further includes a first substrate (21) and a functional layer (22) connected to the first substrate (21). The photosensitive unit (5) is bonded to the side of the functional layer (22) away from the first substrate (21). The functional layer (22) includes a transmitting module, a receiving module and a data conversion module connected to the transmitting module and the receiving module, all disposed on the first substrate (21).

3. The optical communication module as described in claim 1, characterized in that: The optical transceiver module (10) further includes a first substrate (21), a second substrate (23), and a functional layer (22). The functional layer (22) is connected to the first substrate (21), and the photosensitive unit (5) is disposed on the side of the functional layer (22) away from the first substrate (21). The functional layer (22) includes a transmitting module and a receiving module disposed on the first substrate (21), and the second substrate (23) is provided with a data conversion module connected to the transmitting module and the receiving module.

4. The optical communication module as described in claim 1, characterized in that: The optical communication module further includes an intermediary layer (7), which is disposed between the circuit board (1) and the optical transceiver module (10), and the circuit board (1) and the optical transceiver module (10) are electrically connected through the intermediary layer (7).

5. The optical communication module as described in claim 1, characterized in that: The semiconductor substrate (41) is provided with a secondary microlens (55) covering the photosensitive unit (5).

6. The optical communication module as described in claim 5, characterized in that: The semiconductor substrate (41) includes a first surface (411) and a second surface (412) disposed opposite to each other. The photosensitive unit (5) is disposed on the first surface (411). The second surface (412) includes a groove (413) disposed thereon. The secondary microlens (55) is disposed in the groove (413).

7. A method for fabricating an optical communication module, characterized in that, Includes the following steps: Step S1: A first doped layer (51) and a second doped layer (53) perpendicular to the semiconductor substrate (41) are implanted at intervals on the semiconductor substrate (41) to form a photosensitive unit (5); Step S2: Deposit and etch an electrical connection layer (44) having a gate structure, a dielectric layer structure and metal traces on the semiconductor substrate (41); wherein the gate structure, the metal traces, the first doped layer (51) and the second doped layer (53) are connected; Step S3: Bond the light-emitting element (42) onto the semiconductor substrate (41) and combine it with the photosensitive unit (5) to form an optical transceiver module (10). Step S4: Optically couple the light-emitting element (42) of one of the optical transceiver modules (10) to the photosensitive unit (5) of the other optical transceiver module (10) via an optical fiber (6).

8. The method for fabricating an optical communication module as described in claim 7, characterized in that, Before step S3, there is step S2.1: a functional layer (22) is bonded to the side of the electrical connection layer (44) facing away from the semiconductor substrate (41), the functional layer (22) including a transmitting module and a receiving module; and / or, the functional layer (22) also includes a data conversion module.

9. The method for fabricating an optical communication module as described in claim 7, characterized in that, Step S2.2 precedes step S3: a groove (413) is etched on one side of the semiconductor substrate (41) opposite to the first doped layer (51) and the second doped layer (53), and a secondary microlens (55) is bonded in the groove (413).

10. The method for fabricating an optical communication module as described in claim 8, characterized in that, Before step S4, there is step S3.2: which further includes the step of providing an interposer (7) to bond the functional layer (22), electrical connection layer and semiconductor substrate (41) together to the interposer (7), and the interposer (7) is flip-chip soldered to the circuit board (1).

11. The method for fabricating an optical communication module as described in claim 10, characterized in that, After step S3 and before step S4, there is step S3.1: providing a second substrate (23), repeatedly sputtering metal, etching, and depositing an insulating medium on the second substrate (23) to form an independent chip with a SerDes module; Step S4 is followed by step S4.1: soldering the individual chip onto the interposer layer (7).

12. The method for fabricating an optical communication module as described in claim 8, characterized in that, The step S3 is preceded by step S2.2: providing a second substrate (23), repeatedly sputtering metal, etching, and depositing an insulating medium on the second substrate (23) to form a processing layer with a SerDes module, and bonding the processing layer to the first substrate (21).

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