Optical transceiver and manufacturing method thereof

Abstract

The present disclosure provides an optical transceiver and a method for manufacturing the same. The optical transceiver includes: a three-dimensionally integrated first semiconductor structure and a second semiconductor structure; the first semiconductor structure includes: a photodetector, a driver chip, a first waveguide structure, a plurality of first metal electrodes, and a plurality of first conductive via structures; wherein the driver chip is electrically connected to the plurality of first metal electrodes via the plurality of first conductive via structures; the second semiconductor structure includes: an electro-optical modulation layer, the electro-optical modulation layer covering the first waveguide structure and the plurality of first metal electrodes; wherein the electro-optical modulation layer is electrically connected to the plurality of first metal electrodes; and the electro-optical modulation layer, the first waveguide structure, and the plurality of first metal electrodes constitute a modulator.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the technical field of optoelectronic devices, and in particular to an optical transceiver and a method for manufacturing the same. Background Art

[0002] Silicon photonics is a next-generation technology based on silicon and silicon-based substrate materials (such as SiGe / Si and silicon-on-insulator), utilizing existing complementary metal oxide semiconductor (CMOS) processes for the development and integration of optical devices. Silicon photonics combines the ultra-large-scale, ultra-high-precision manufacturing capabilities of integrated circuit technology with the ultra-high speed and ultra-low power consumption of photonics, representing a disruptive technology that addresses the erosion of Moore's Law. This combination leverages the scalability of semiconductor wafer manufacturing, thereby reducing costs.

[0003] However, the bandwidth limit of pure silicon optical modulators based on carrier dispersion effect is about 80GHz, and there is little room for improvement at this stage. Summary of the Invention

[0004] In view of this, embodiments of the present disclosure provide an optical transceiver and a method for manufacturing the same in order to solve at least one technical problem existing in the prior art.

[0005] To achieve the above objectives, the technical solution of the present disclosure is implemented as follows:

[0006] In a first aspect, an embodiment of the present disclosure provides an optical transceiver, the optical transceiver comprising: a three-dimensionally integrated first semiconductor structure and a second semiconductor structure;

[0007] The first semiconductor structure includes: a photodetector, a driver chip, a first waveguide structure, a plurality of first metal electrodes and a plurality of first conductive via structures; wherein the driver chip is electrically connected to the plurality of first metal electrodes through the plurality of first conductive via structures;

[0008] The second semiconductor structure includes: an electro-optical modulation layer, which covers the first waveguide structure and the plurality of first metal electrodes; wherein the electro-optical modulation layer is electrically connected to the plurality of first metal electrodes; the electro-optical modulation layer, the first waveguide structure and the plurality of first metal electrodes constitute a modulator.

[0009] In some embodiments, the first semiconductor structure and the second semiconductor structure are connected by flip-chip bonding.

[0010] In some embodiments, the driving chip is formed on a first substrate; the photodetector, the first waveguide structure and the plurality of first metal electrodes are formed on a silicon-on-insulator (SOI); and the SOI is located on the driving chip.

[0011] In some embodiments, the first semiconductor structure further includes: a dielectric layer located on the SOI; wherein the first conductive via structure sequentially penetrates the dielectric layer and the SOI.

[0012] In some embodiments, the photodetector comprises:

[0013] Silicon layer; wherein the SOI includes a bottom silicon layer, a buried oxide layer and a top silicon layer in sequence, and the silicon layer is formed by etching the top silicon layer;

[0014] a germanium absorption layer, located on the silicon layer;

[0015] An N-type doping structure and a P-type doping structure are located on the buried oxide layer; the silicon layer and the germanium absorption layer are located between the N-type doping structure and the P-type doping structure;

[0016] two second metal electrodes, the two second metal electrodes being respectively located on the N-type doped structure and the P-type doped structure;

[0017] Two second conductive through-hole structures are electrically connected to the two second metal electrodes respectively.

[0018] In some embodiments, the first semiconductor structure further comprises:

[0019] A transimpedance amplifier chip is formed on the first substrate, and the transimpedance amplifier chip is electrically connected to the two second metal electrodes through two second conductive through-hole structures.

[0020] In some embodiments, the first semiconductor structure further comprises:

[0021] a first solder ball, wherein the first conductive through-hole structure and the driver chip are electrically connected via the first solder ball;

[0022] A second solder ball is provided, and the second conductive via structure and the transimpedance amplifier chip are electrically connected via the second solder ball.

[0023] In some embodiments, the first semiconductor structure further comprises:

[0024] The second waveguide structure is located in the dielectric layer; wherein the orthographic projections of the first waveguide structure and the second waveguide structure on the first substrate at least partially overlap.

[0025] In some embodiments, the first semiconductor structure further comprises:

[0026] A resistance unit is located in the dielectric layer and below the modulator; wherein the resistance unit is used to heat the first waveguide structure and the second waveguide structure, or the resistance unit is used to achieve impedance matching between the modulator and the first metal electrode.

[0027] In some embodiments, along the transmission direction of the optical signal, the first waveguide structure includes: an optical beam splitter, an optical combiner, and a dual-path waveguide structure located between the optical beam splitter and the optical combiner; wherein, the optical beam splitter splits the input light and couples the light into the electro-optical modulation layer through the dual-path waveguide structure respectively, and the light modulated by the electro-optical modulation layer is then coupled into the dual-path waveguide structure, and is output after interference through the optical combiner.

[0028] In some embodiments, the material of the electro-optic modulation layer is lithium niobate.

[0029] In a second aspect, an embodiment of the present disclosure provides a method for manufacturing an optical transceiver, wherein the optical transceiver includes: a first semiconductor structure and a second semiconductor structure that are three-dimensionally integrated; the manufacturing method includes:

[0030] Forming the first semiconductor structure includes: providing a first substrate; forming a photodetector and a driver chip on the first substrate; forming a dielectric layer on the photodetector and the driver chip; forming a plurality of first conductive via structures, a plurality of first metal electrodes, and a first waveguide structure in the dielectric layer; the driver chip is electrically connected to the plurality of first metal electrodes through the plurality of first conductive via structures;

[0031] Forming the second semiconductor structure includes: providing a second substrate; forming an electro-optical modulation layer on the second substrate;

[0032] The second semiconductor structure is flip-chip bonded to the first semiconductor structure so that the electro-optical modulation layer covers the first waveguide structure and the plurality of first metal electrodes; wherein the electro-optical modulation layer is electrically connected to the plurality of first metal electrodes; the electro-optical modulation layer, the first waveguide structure and the plurality of first metal electrodes constitute a modulator.

[0033] In some embodiments, forming a photodetector and a driver chip on the first substrate includes:

[0034] forming a transimpedance amplifier chip and a driver chip on the first substrate;

[0035] forming a silicon-on-insulator (SOI) on the transimpedance amplifier chip and the driver chip; wherein the SOI sequentially comprises a bottom silicon layer, a buried oxide layer, and a top silicon layer;

[0036] The photodetector is formed on the SOI.

[0037] In some embodiments, forming the photodetector on the SOI includes:

[0038] Etching the top silicon layer to form a silicon layer;

[0039] forming an N-type doping structure and a P-type doping structure on the buried oxide layer, wherein the silicon layer is located between the N-type doping structure and the P-type doping structure;

[0040] forming two second conductive via structures and two second metal electrodes, wherein the two second metal electrodes are in contact with the N-type doped structure and the P-type doped structure respectively; and the two second conductive via structures are electrically connected to the two second metal electrodes respectively;

[0041] A germanium absorption layer is formed on the silicon layer, and the germanium absorption layer is located between the two second metal electrodes.

[0042] In some embodiments, forming a plurality of first conductive via structures in the dielectric layer includes:

[0043] forming a first dielectric layer on the photodetector and the driver chip;

[0044] Etching to form a plurality of first through holes that sequentially penetrate the first dielectric layer, the buried oxide layer, and the bottom silicon layer;

[0045] A conductive material is filled in the first through holes to form a plurality of first conductive through hole structures.

[0046] In some embodiments, forming a plurality of first metal electrodes in the dielectric layer includes:

[0047] forming a second dielectric layer on the plurality of first conductive via structures;

[0048] Etching the second dielectric layer to form a plurality of first grooves, wherein each of the first grooves exposes the first conductive through-hole structure;

[0049] A metal material is filled in the first grooves to form a plurality of first metal electrodes.

[0050] In some embodiments, forming a first waveguide structure in the dielectric layer includes:

[0051] etching the second dielectric layer to form a plurality of first grooves while etching the second dielectric layer to form a second groove;

[0052] The second groove is filled with a waveguide material to form a first waveguide structure.

[0053] The embodiment of the present disclosure provides an optical transceiver and a method for manufacturing the same. The optical transceiver includes: a three-dimensionally integrated first semiconductor structure and a second semiconductor structure; the first semiconductor structure includes: a photodetector, a driver chip, a first waveguide structure, a plurality of first metal electrodes and a plurality of first conductive through-hole structures; wherein the driver chip is electrically connected to the plurality of first metal electrodes through the plurality of first conductive through-hole structures; the second semiconductor structure includes: an electro-optical modulation layer, the electro-optical modulation layer covers the first waveguide structure and the plurality of first metal electrodes; wherein the electro-optical modulation layer is electrically connected to the plurality of first metal electrodes; the electro-optical modulation layer, the first waveguide structure and the plurality of first metal electrodes constitute a modulator. In the embodiment of the present disclosure, the driver chip is electrically connected to the plurality of first metal electrodes through the plurality of first conductive through-hole structures, and the integration between the driver chip and the modulator is achieved by utilizing the plurality of first conductive through-hole structures, which is conducive to reducing the loss of high-frequency signals and improving the quality of signals.

[0054] In addition, in the embodiment of the present disclosure, the first semiconductor structure includes a photodetector and a driver chip. The first waveguide structure, multiple first metal electrodes and multiple first conductive through-hole structures arranged in the first semiconductor structure and the electro-optical modulation layer arranged in the second semiconductor structure together constitute a modulator. The photodetector, modulator and chip are three-dimensionally integrated, which can not only improve the integration of the device, but also improve the signal transmission rate and bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A schematic cross-sectional view of an optical transceiver provided in an embodiment of the present disclosure;

[0056] Figure 2 A schematic perspective structural diagram of a modulator provided in an embodiment of the present disclosure;

[0057] Figure 3 A perspective structural diagram of a first waveguide structure and a second waveguide structure provided in an embodiment of the present disclosure;

[0058] Figure 4 A schematic flow chart of a method for manufacturing an optical transceiver provided in an embodiment of the present disclosure;

[0059] The figure includes: 100, first semiconductor structure; 101, first substrate; 102, isolation layer; 103, driver chip; 104, transimpedance amplifier chip; 105, bottom silicon; 106, buried oxide layer; 107, dielectric layer; 108, first waveguide structure; 109, first metal electrode; 110, first conductive via structure; 111, first solder ball; 112, resistor unit; 113, silicon layer; 114, germanium absorption layer; 115, N-type doping structure; 116, P-type doping structure; 117, second metal electrode; 118, second conductive via structure; 119, second waveguide structure; 120, second solder ball; 121, optical beam splitter; 122, first branch waveguide structure; 123, second branch waveguide structure; 124, optical combiner; 200, second semiconductor structure; 201, second substrate; 202, electro-optical modulation layer. DETAILED DESCRIPTION

[0060] The following will clearly and completely describe the technical solutions in the embodiments of the present disclosure in conjunction with the embodiments of the present disclosure and the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present disclosure.

[0061] In the following description, numerous specific details are provided to provide a more thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure can be practiced without one or more of these details. In other instances, certain technical features known in the art are not described to avoid confusion with the present disclosure; that is, all features of actual embodiments are not described herein, nor are well-known functions and structures described in detail.

[0062] In the drawings, the sizes of layers, regions, elements and their relative sizes may be exaggerated for clarity. Like reference numerals denote like elements throughout.

[0063] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to, or coupled to" another element or layer, it may be directly on, adjacent to, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on, directly adjacent to, directly connected to, or directly coupled to" another element or layer, there may be no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Therefore, without departing from the teachings of the present disclosure, the first element, component, region, layer, or part discussed below may be represented as a second element, component, region, layer, or part. However, when the second element, component, region, layer, or part is discussed, it does not necessarily mean that the first element, component, region, layer, or part exists in the present disclosure.

[0064] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein for convenience of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that in addition to the orientations shown in the figures, the spatially relative terms are intended to include different orientations of the device in use and operation. For example, if the device in the drawings is flipped, then the elements or features described as "under the other elements" or "under it" or "under it" will be oriented as "on" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or in other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0065] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present disclosure. When used herein, the singular forms "a", "an", and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0066] In order to fully understand the present disclosure, detailed steps and detailed structures will be presented in the following description to illustrate the technical solution of the present disclosure. The preferred embodiments of the present disclosure are described in detail below. However, in addition to these detailed descriptions, the present disclosure may also have other implementation methods.

[0067] refer to Figure 1 , Figure 1 This is a schematic diagram of the cross-sectional structure of the optical transceiver provided in the embodiment of the present disclosure. Figure 1 As shown, the optical transceiver provided by the embodiment of the present disclosure includes: a first semiconductor structure 100 and a second semiconductor structure 200 that are three-dimensionally integrated;

[0068] The first semiconductor structure 100 includes: a photodetector, a driver chip 103, a first waveguide structure 108, a plurality of first metal electrodes 109 and a plurality of first conductive via structures 110; wherein the driver chip 103 is electrically connected to the plurality of first metal electrodes 109 through the plurality of first conductive via structures 110;

[0069] The second semiconductor structure 200 includes: an electro-optical modulation layer 202, the electro-optical modulation layer 202 covers the first waveguide structure 108 and multiple first metal electrodes 109; wherein, the electro-optical modulation layer 202 is electrically connected to the multiple first metal electrodes 109; the electro-optical modulation layer 202, the first waveguide structure 108 and the multiple first metal electrodes 109 constitute a modulator.

[0070] Here, the modulator includes a first waveguide structure and a plurality of first metal electrodes disposed in a first semiconductor structure, and an electro-optical modulation layer disposed in a second semiconductor structure.

[0071] Here, the driver chip (Driver) can be used to provide a driving signal to the modulator.

[0072] In some embodiments, the first semiconductor structure 100 and the second semiconductor structure 200 are connected via flip-chip bonding. Here, the electro-optical modulation layer is hybrid-integrated with the silicon-on-insulator (SOI) within the first semiconductor using flip-chip bonding technology, which has a high process tolerance.

[0073] Here, the second semiconductor structure 200 includes: a second substrate 201 and an electro-optical modulation layer 202 located on the second substrate 201. After the second semiconductor structure is manufactured on other process platforms, the second semiconductor structure is invertedly bonded to the first semiconductor structure at positions corresponding to the first waveguide structure and the plurality of first metal electrodes, so that the electro-optical modulation layer covers the first waveguide structure and the plurality of first metal electrodes. Figure 1 As shown, the electro-optic modulation layer 202 is inverted above the first waveguide structure 108 and the plurality of first metal electrodes 109 .

[0074] In a specific example, the second substrate may be a quartz substrate.

[0075] Here, the electro-optic modulation layer can be a slab waveguide structure or a ridge waveguide structure. For example, a lithium niobate thin film can be formed on the second substrate as the electro-optic modulation layer. Compared to silicon optical modulators, lithium niobate thin film optical modulators can achieve a theoretical bandwidth of 500 GHz, which helps to improve the modulator's bandwidth.

[0076] If the electro-optical modulation layer is a planar waveguide structure, the second semiconductor structure is invertedly bonded to the first semiconductor structure so that the electro-optical modulation layer covers the first waveguide structure and the plurality of first metal electrodes. For another example, after a lithium niobate thin film is formed on the second substrate, the lithium niobate is etched to form a ridge waveguide structure. If the electro-optical modulation layer is a ridge waveguide structure, the second semiconductor structure is invertedly bonded to the first semiconductor structure. In this case, grooves are provided at corresponding positions of the first semiconductor structure, so that the ridge of the ridge waveguide structure on the second semiconductor structure corresponds to the groove on the first semiconductor structure, the ridge and groove of the ridge waveguide structure interlock with each other, and the ridge of the ridge waveguide structure on the second semiconductor structure corresponds to the position of the first waveguide structure within the first semiconductor structure. In other words, the ridge of the ridge waveguide structure and the orthographic projection of the first waveguide structure on the second substrate at least partially overlap.

[0077] Still Figure 1 As shown, the first semiconductor structure 100 includes: a first substrate 101 and an isolation layer 102 located on the first substrate 101 ; a driver chip 103 and a transimpedance amplifier chip 104 are disposed in the isolation layer 102 .

[0078] Here, the first substrate may be divided into a first region for forming a modulator and a second region for forming a photodetector; wherein the driver chip is located in the first region, and the transimpedance amplifier chip is located in the second region.

[0079] Here, the photodetector is used to convert the optical signal into an electrical signal, and the transimpedance amplifier (TIA) chip is used to amplify the electrical signal and output it.

[0080] Here, the first substrate can be a semiconductor substrate; specifically, it includes at least one elemental semiconductor material (for example, a silicon (Si) substrate, a germanium (Ge) substrate, etc.), at least one III-V compound semiconductor material (for example, a gallium nitride (GaN) substrate, a gallium arsenide (GaAs) substrate, an indium phosphide (InP) substrate, etc.), at least one II-VI compound semiconductor material, at least one organic semiconductor material or other semiconductor materials known in the art.

[0081] Still Figure 1As shown, the first semiconductor structure 100 further includes: an SOI located on the driver chip 103, the SOI sequentially comprising a bottom silicon layer 105, a buried oxide layer 106, and a top silicon layer; the top silicon layer is etched during the photodetector formation process to form a silicon layer 113 in the photodetector. A dielectric layer 107 located on the SOI includes a first waveguide structure 108, a plurality of first metal electrodes 109, and a plurality of first conductive via structures 110. The upper surface of the dielectric layer 107 is flush with the upper surfaces of the plurality of first metal electrodes 109, and the plurality of first conductive via structures 110 sequentially penetrates the dielectric layer 107 and the SOI (including the buried oxide layer 106 and the bottom silicon layer 105).

[0082] Here, a first through hole can be formed by sequentially etching the dielectric layer, the buried oxide layer, and the underlying silicon layer; and a conductive material is filled in the first through hole to form a first conductive through hole structure, wherein the first conductive through hole structure is used to electrically connect the modulator and the driver chip.

[0083] In a specific example, the first conductive through-hole structure may be a metal copper via (Through Silicon Via, TSV). Here, the metal copper via has an interconnection characteristic of 3 dB bandwidth ≥ 110 GHz.

[0084] In related technical solutions, the integration of the modulator and driver chip is limited to gold wire bonding, which introduces additional high-frequency losses and degrades signal quality. In the disclosed embodiment, the driver chip is electrically connected to the multiple first metal electrodes via multiple first conductive via structures. Utilizing these multiple first conductive via structures enables integration between the driver chip and modulator, which helps reduce high-frequency signal losses and improve signal quality.

[0085] Furthermore, in the optical transceiver provided by the embodiments of the present disclosure, during the formation of the first semiconductor structure, a first via is formed solely by etching the dielectric layer, buried oxide layer, and underlying silicon. This first via is then filled to form a first conductive via structure. This first conductive via structure, which penetrates only the dielectric layer, buried oxide layer, and underlying silicon, connects the first metal electrode of the modulator to the driver chip. In other words, in the optical transceiver provided by the embodiments of the present disclosure, the first conductive via structure is already formed before the first and second semiconductor structures are flip-chip bonded.

[0086] Here, the upper surface of the dielectric layer is flush with the upper surface of the first waveguide structure, or there is a preset distance between the upper surface of the dielectric layer and the upper surface of the first waveguide structure. Figure 1As shown, the first waveguide structure is in direct contact with the electro-optical modulation layer. If a preset distance exists between the upper surface of the dielectric layer and the upper surface of the first waveguide structure, and the dielectric layer material is filled between the first waveguide structure and the electro-optical modulation layer, ensuring the preset distance is within a range of 100 nm to 300 nm, the optical signal within the first waveguide structure can be coupled into the electro-optical modulation layer.

[0087] refer to Figure 2 , Figure 2 A schematic diagram of the perspective structure of a modulator provided in an embodiment of the present disclosure. For ease of explanation, Figure 2 Only indicates Figure 1 The first waveguide structure 108 is located in the modulator. Figure 2 As shown, along the transmission direction of the optical signal, the first waveguide structure includes: an optical beam splitter 121, an optical beam combiner 124, and a dual-path waveguide structure located between the optical beam splitter 121 and the optical beam combiner 124 (i.e., a first branch waveguide structure 122 and a second branch waveguide structure 123). The optical beam splitter 121 splits the input light and couples the light into the electro-optical modulation layer 202 through the dual-path waveguide structure. The light modulated by the electro-optical modulation layer 202 is then coupled into the dual-path waveguide structure, and is output after interference through the optical beam combiner 124. The first metal electrode 109 can provide an electrical modulation signal for the first waveguide structure.

[0088] Here, the optical beam splitter, optical combiner, dual-path waveguide structure located between the optical beam splitter and the optical combiner, and electro-optical modulation layer constitute a Mach-Zehnder interferometer (MZI) structure. The optical beam splitter is used to split the input light into two equal beams. The two beams enter the two arms of the Mach-Zehnder interferometer structure (i.e., the dual-path waveguide structure). The two beams are then coupled into the electro-optical modulation layer. During transmission within the electro-optical modulation layer, the light is affected by the electrical modulation signal, causing its phase to be modulated. The two beams modulated by the electro-optical modulation layer are then coupled into the dual-path waveguide structure. They then interfere with each other through the optical combiner, and the final output light is the modulated optical signal.

[0089] Still refer to Figure 2 The optical beam splitter 121 has a first input end and a second input end, and the light source inputs the optical signal into the optical beam splitter 121 through the first input end and the second input end; the first output end of the optical beam splitter 121 is connected to the first branch waveguide structure 122, and the second output end of the optical beam splitter is connected to the second branch waveguide structure 123; after the first branch waveguide structure 122 and the second branch waveguide structure 123 input the optical signal into the optical combiner 124, the optical signal is output through the first output end and the second output end of the optical combiner 124, thereby constructing a 2×2 splitter / combiner.

[0090] Figure 2 The diagram illustrates that, along the transmission direction of the optical signal, the width of the first branch waveguide structure perpendicular to the transmission direction of the optical signal first decreases and then increases, while the width of the second branch waveguide structure perpendicular to the transmission direction of the optical signal first decreases and then increases. Here, the width directions of the first branch waveguide structure and the first branch waveguide structure are parallel to the plane of the first substrate, and the width directions of the first branch waveguide structure and the first branch waveguide structure are perpendicular to the transmission direction of the optical signal.

[0091] In one specific example, the material of the first waveguide structure may be silicon. In another specific example, the material of the first waveguide structure may also be silicon nitride.

[0092] like Figure 1 As shown, a second waveguide structure 119 is further provided in the dielectric layer 107 , wherein the orthographic projections of the first waveguide structure 108 and the second waveguide structure 119 on the first substrate 101 at least partially overlap.

[0093] refer to Figure 3 , Figure 3 A perspective structural diagram of the first waveguide structure and the second waveguide structure provided in an embodiment of the present disclosure. Figure 3 It is shown that the first waveguide structure 108 and the second waveguide structure 119 partially overlap, and the size of the overlapping portion of the first waveguide structure 108 and the second waveguide structure 119 along the extension direction of the first waveguide structure 108 or the second waveguide structure 119 is L1.

[0094] If the first waveguide structure 108 and the second waveguide structure 119 are both made of silicon nitride, the thickness of the first waveguide structure 108 in a direction perpendicular to the first substrate is 300nm to 500nm; the thickness of the second waveguide structure 119 in a direction perpendicular to the first substrate is 100nm to 300nm; and the dimension of the overlapping portion of the first waveguide structure 108 and the second waveguide structure 119 along the extension direction of the first waveguide structure 108 or the second waveguide structure 119 is 10μm to 150μm. In addition, the first and second waveguide structures made of silicon nitride and the electro-optical modulation layer made of lithium niobate are all materials that support an optical transparency band of 400nm to 2000nm. Therefore, the modulator and photodetector within the optical transceiver provided in the embodiments of the present disclosure will also support a wavelength range of 400nm to 2000nm.

[0095] If the materials of the first waveguide structure 108 and the second waveguide structure 119 are both silicon, the thickness of the first waveguide structure 108 along the direction perpendicular to the first substrate is 150nm to 300nm; the thickness of the second waveguide structure 119 along the direction perpendicular to the first substrate is 100nm to 200nm; the size of the overlapping part of the first waveguide structure 108 and the second waveguide structure 119 along the extension direction of the first waveguide structure 108 or the second waveguide structure 119 is 30μm to 200μm.

[0096] Here, a portion of the second waveguide structure can be located below the first waveguide structure, and after the optical signal is input into the second waveguide structure, it can be coupled to the first waveguide structure and then coupled to the modulator; and another portion of the second waveguide structure can be located above the photodetector, and after the optical signal is input into the second waveguide structure, it can also be coupled to the photodetector.

[0097] In one specific example, the first and second waveguide structures may be made of silicon. In another specific example, the first and second waveguide structures may be made of silicon nitride. Because the refractive index of silicon nitride is 1.98 and the refractive index of silicon is 3.4, using silicon as the waveguide structure provides better optical signal confinement and a relatively smaller waveguide structure size.

[0098] In some embodiments, a distance between the first waveguide structure and the second waveguide structure in a direction perpendicular to the first substrate ranges from 100 nm to 600 nm to ensure appropriate coupling efficiency.

[0099] Here, the upper surface of the dielectric layer is flush with the upper surfaces of the plurality of first metal electrodes, and the electro-optical modulation layer covers the upper surfaces of the dielectric layer and the plurality of first metal electrodes. Thus, the electro-optical modulation layer is in direct contact with the plurality of first metal electrodes, and the first metal electrodes provide electrical modulation signals to the first waveguide structure.

[0100] Here, the first metal electrode of the lithium niobate modulator is fabricated on SOI using a silicon photonics CMOS process. For example, a dielectric layer is deposited on SOI, etched, and filled to form a first conductive via structure. A first metal material layer can then be deposited on the upper surface of the first conductive via structure and the dielectric layer, and the first metal material layer can be etched to form the first metal electrode. For another example, a first dielectric layer is deposited on SOI, etched, and filled to form a first conductive via structure; a second dielectric layer is formed, and the second dielectric layer is etched to form a first recess exposing the first conductive via structure; and a metal material is filled into the first recess to form the first metal electrode.

[0101] Here, the first metal electrode can adopt either a single-ended driving mode or a differential driving mode.

[0102] Here, high-efficiency modulation is achieved by properly arranging the positions of the electro-optic modulation layer and the first metal electrode. For example, the center of the electro-optic modulation layer is located at the center of the electrode spacing of the first metal electrode.

[0103] In one specific example, the first metal electrode may be made of copper. In another specific example, the first metal electrode may be made of aluminum.

[0104] In the disclosed embodiment, the driver chip transmits a high-frequency electrical signal to the first metal electrode in the upper layer through the first conductive via structure. Because the electro-optic modulation layer exhibits an electro-optic effect, i.e., when a voltage is applied to the electro-optic modulation layer, the refractive index of the electro-optic modulation layer changes, thereby modulating the phase, amplitude, intensity, and polarization state of the optical signal. Here, the electro-optic effect includes the linear electro-optic effect, i.e., the Pockels effect, and the quadratic electro-optic effect, i.e., the Kerr effect.

[0105] In some embodiments, the first semiconductor structure 100 further includes: a resistance unit 112, located in the dielectric layer 107, and the resistance unit 112 is located below the modulator; wherein the resistance unit 112 is used to heat the first waveguide structure 108 and the second waveguide structure 119, or the resistance unit 112 is used to achieve impedance matching between the modulator and the first metal electrode 109.

[0106] Here, the resistance unit is located below the dual-path waveguide structure and can be used to achieve impedance matching between the modulator and the first metal electrode to improve the modulation efficiency of the modulator.

[0107] Here, the resistance unit is located below the dual-path waveguide structure, and the heat energy of the resistance unit is used to heat the first waveguide structure and the second waveguide structure through thermal radiation, thereby improving the temperature distribution near the first waveguide structure and the second waveguide structure, thereby affecting the mode field distribution in the first waveguide structure and the second waveguide structure to achieve phase adjustment of the optical signal.

[0108] In the embodiment of the present disclosure, the material of the resistance unit includes but is not limited to titanium nitride.

[0109] like Figure 1 As shown, the first semiconductor structure 100 further includes a first solder ball 111 , and the first conductive via structure 110 and the driver chip 103 are electrically connected via the first solder ball 111 .

[0110] In the embodiment of the present disclosure, the material of the first solder ball may include a metal or metal alloy having conductive properties, for example, silver, copper, or an alloy containing copper and silver.

[0111] like Figure 1As shown, the photodetector includes: a silicon layer 113; wherein the SOI includes a bottom silicon 105, a buried oxide layer 106 and a top silicon, and the silicon layer 113 is formed by etching the top silicon; a germanium absorption layer 114, located on the silicon layer 113; an N-type doped structure 115 and a P-type doped structure 116, located on the buried oxide layer 106; the silicon layer 113 and the germanium absorption layer 114 are located between the N-type doped structure 115 and the P-type doped structure 116; two second metal electrodes 117, the two second metal electrodes 117 are respectively located on the N-type doped structure 115 and the P-type doped structure 116; two second conductive through-hole structures 118, the two second conductive through-hole structures 118 are respectively electrically connected to the two second metal electrodes 117.

[0112] Here, after the optical signal is input into the second waveguide structure, it can be coupled to the germanium absorption layer and converted into an electrical signal through a photodetector. The electrical signal can be amplified and output using a transimpedance amplifier chip.

[0113] In a specific example, the material of the first metal electrode may be copper.

[0114] Here, a second through hole can be formed by sequentially etching the dielectric layer, the buried oxide layer, and the underlying silicon layer, and then filled with a conductive material to form a second conductive through hole structure. The second conductive through hole structure is used to electrically connect the photodetector and the transimpedance amplifier chip.

[0115] In a specific example, the second conductive through-hole structure may be a metal copper via.

[0116] In the embodiment of the present disclosure, the radio frequency connection method of the high-speed electric chip (i.e., the transimpedance amplifier chip and the driver chip) and the optical chip (i.e., the lithium niobate modulator and the silicon germanium photodetector) will greatly affect the signal transmission and loading quality, including signal integrity, microwave loss, impedance continuity, parasitic capacitance, parasitic inductance, etc. The use of a three-dimensional integrated stacking method based on TSV technology will effectively reduce the high-frequency signal connection distance between the electric chip and the optical chip, which is very conducive to achieving signal transmission with a bandwidth greater than 100GHz. In addition, the use of a three-dimensional integrated optoelectronic chip structure will greatly improve the integration density, provide greater high-frequency connection freedom, and have strong scalability. In the embodiment of the present disclosure, the lithium niobate modulator and the driver electric chip are electrically connected through a first conductive through-hole structure, and the photodetector and the transimpedance amplifier chip are electrically connected through a second conductive through-hole structure, which will realize a high-density, large-bandwidth optical transceiver.

[0117] like Figure 1 As shown, the first semiconductor structure 100 further includes a second solder ball 120 , and the second conductive via structure 118 and the transimpedance amplifier chip 104 are electrically connected via the second solder ball 120 .

[0118] In the embodiment of the present disclosure, the material of the second solder ball may include a metal or metal alloy having conductive properties, for example, silver, copper, or an alloy containing copper and silver.

[0119] It should be noted that the first solder ball is located on the electrode of the driver chip and is used to electrically lead out the driver chip; the second solder ball is located on the electrode of the transimpedance amplifier chip and is used to electrically lead out the transimpedance amplifier chip.

[0120] Here, the driver chip and the transimpedance amplifier chip can be powered by connecting to peripheral circuits.

[0121] An embodiment of the present disclosure provides an optical transceiver with a three-dimensional integrated photodetector and modulator, wherein the second waveguide structure and the lateral PIN-type germanium silicon photodetector together constitute an optical receiving end to realize signal reception; the first waveguide structure constructs a 2×2 beam splitter / combiner and a Mach-Zehnder interferometer waveguide structure, and constitutes an optical signal modulation end with the lithium niobate electro-optical modulation layer and the first metal electrode to realize signal transmission; the second waveguide structure and the first waveguide structure can realize mutual coupling and transition of optical signals; the second metal electrode of the photodetector and the transimpedance amplifier electronic chip are interconnected through a second conductive through-hole structure, and the first metal electrode of the modulator and the driver chip are interconnected through the first conductive through-hole structure; the resistance unit (for example, a titanium nitride resistance unit) can be used to heat the second waveguide structure and the first waveguide structure, and can also be used to realize the terminal resistance matching function of the modulator; the first metal electrode of the lithium niobate modulator is prepared on SOI through a silicon photonic CMOS process. The embodiment of the present disclosure provides a three-dimensional integrated solution with a lithium niobate modulator, a silicon germanium photodetector, a driver chip, and a transimpedance amplifier chip, which has the characteristics of large tolerance of the manufacturing process, high integration, small size, and high speed.

[0122] The optical transceiver provided by the embodiment of the present disclosure has the following beneficial effects: (1) The optical transceiver provided by the embodiment of the present disclosure can realize the three-dimensional integration of the optical chip (i.e., lithium niobate modulator and silicon germanium photodetector) and the electrical chip (i.e., transimpedance amplifier chip and driver chip), which will greatly improve the overall bandwidth and speed of the chip; (2) The optical transceiver provided by the embodiment of the present disclosure utilizes the silicon photonics process platform to process the key core components of the chip and then integrates the lithium niobate electro-optical modulation layer, which fully realizes the performance advantages of each component; (3) The optical transceiver provided by the embodiment of the present disclosure, the lithium niobate modulator The first metal electrode is processed on a silicon photonics platform, which is different from the electrode preparation of the previous lithium niobate modulator, and is conducive to large-scale production and reduces costs; (4) The optical transceiver provided by the embodiment of the present disclosure, the second waveguide structure and the first waveguide structure serve as the optical transmission and coupling functions of the receiving end and the transmitting end, which increases the flexibility and freedom of chip design; (5) Unetched planar lithium niobate is used as the electro-optical modulation layer, and a flip-chip bonding process is used to achieve hybrid integration with the SOI chip, which greatly improves the process alignment tolerance and will improve the yield, consistency and comprehensive performance of the overall chip.

[0123] refer to Figure 4 , Figure 4 Schematic diagram of the process of manufacturing the optical transceiver provided in the embodiment of the present disclosure. Figure 4 As shown, the optical transceiver provided by the embodiment of the present disclosure includes a first semiconductor structure and a second semiconductor structure that are three-dimensionally integrated. The manufacturing method of the optical transceiver includes the following steps:

[0124] Step S401: forming a first semiconductor structure, including: providing a first substrate; forming a photodetector and a driver chip on the first substrate; forming a dielectric layer on the photodetector and the driver chip; forming a plurality of first conductive via structures, a plurality of first metal electrodes, and a first waveguide structure in the dielectric layer; and electrically connecting the driver chip to the plurality of first metal electrodes through the plurality of first conductive via structures.

[0125] Step S402: forming a second semiconductor structure, including: providing a second substrate; forming an electro-optical modulation layer on the second substrate;

[0126] Step S403: Flip-chip bond the second semiconductor structure to the first semiconductor structure so that the electro-optical modulation layer covers the first waveguide structure and the multiple first metal electrodes; wherein the electro-optical modulation layer is electrically connected to the multiple first metal electrodes; the electro-optical modulation layer, the first waveguide structure and the multiple first metal electrodes constitute a modulator.

[0127] In some embodiments, a photodetector and a driver chip are formed on a first substrate, including: forming a transimpedance amplifier chip and a driver chip on the first substrate; forming a silicon-on-insulator (SOI) on the transimpedance amplifier chip and the driver chip; wherein the SOI includes a bottom silicon layer, a buried oxide layer, and a top silicon layer in sequence; and forming the photodetector on the SOI.

[0128] In an embodiment of the present disclosure, forming a first semiconductor structure includes the following steps: providing a first substrate, the first substrate including a first surface and a second surface disposed opposite the first surface; and disposing a driver chip and a transimpedance amplifier chip on the first surface of the first substrate. The first substrate can be divided into a first region for forming a modulator and a second region for forming a photodetector; the driver chip is located in the first region, and the transimpedance amplifier chip is located in the second region.

[0129] Here, the embodiment of the present disclosure is described by taking the first substrate being a silicon substrate as an example.

[0130] Here, SOI may be formed on the driver chip and the transimpedance amplifier chip; wherein the SOI sequentially includes a bottom silicon layer, a buried oxide layer, and a top silicon layer.

[0131] In some embodiments, a photodetector is formed on SOI, including: etching the top silicon to form a silicon layer; forming an N-type doped structure and a P-type doped structure on the buried oxide layer, with the silicon layer located between the N-type doped structure and the P-type doped structure; forming two second conductive via structures and two second metal electrodes, with the two second metal electrodes respectively contacting the N-type doped structure and the P-type doped structure; the two second conductive via structures are electrically connected to the two second metal electrodes, respectively; and forming a germanium absorption layer on the silicon layer, with the germanium absorption layer located between the two second metal electrodes.

[0132] In the embodiment of the present disclosure, a photodetector may be formed on an SOI chip located on a transimpedance amplifier chip, and a signal from the photodetector may be amplified by the transimpedance amplifier chip.

[0133] In some embodiments, forming multiple first conductive through-hole structures in a dielectric layer includes the following steps: forming a first dielectric layer on a photodetector and a driver chip; etching to form multiple first through-holes that sequentially penetrate the first dielectric layer, the buried oxide layer, and the underlying silicon; and filling the multiple first through-holes with conductive material to form multiple first conductive through-hole structures.

[0134] In some embodiments, forming a plurality of first metal electrodes in a dielectric layer includes: forming a second dielectric layer on the plurality of first conductive via structures; etching the second dielectric layer to form a plurality of first grooves; each first groove exposing a first conductive via structure; and filling the plurality of first grooves with metal material to form a plurality of first metal electrodes.

[0135] Here, the material of the first dielectric layer and the material of the second dielectric layer may be the same or different.

[0136] In some embodiments, forming a first waveguide structure in a dielectric layer includes: etching the second dielectric layer to form a plurality of first grooves while etching the second dielectric layer to form second grooves; and filling the second grooves with waveguide material to form the first waveguide structure.

[0137] Here, the first dielectric layer and the second dielectric layer may be formed using methods including but not limited to physical vapor deposition, chemical vapor deposition, atomic layer deposition, or any combination thereof.

[0138] Here, forming the plurality of first through holes, forming the plurality of first grooves, and forming the plurality of second grooves may use wet etching, dry etching, or a combination thereof.

[0139] In the embodiment of the present disclosure, forming the second semiconductor structure includes the following steps: providing a second substrate, the second substrate including a first surface and a second surface arranged opposite to the first surface; forming an electro-optical modulation layer on the first surface of the second substrate.

[0140] In an embodiment of the present disclosure, forming an optical transceiver includes the following steps: flip-chip bonding a second semiconductor structure to a first semiconductor structure so that an electro-optical modulation layer covers the first waveguide structure and a plurality of first metal electrodes; wherein the electro-optical modulation layer is electrically connected to the plurality of first metal electrodes; and the electro-optical modulation layer, the first waveguide structure, and the plurality of first metal electrodes constitute a modulator.

[0141] Here, the first semiconductor structure and the second semiconductor structure may be connected using a flip-chip bonding process.

[0142] In some embodiments, forming the first semiconductor structure further includes: forming a first solder ball, the first conductive via structure and the driver chip are electrically connected via the first solder ball; forming a second solder ball, the second conductive via structure and the transimpedance amplifier chip are electrically connected via the second solder ball.

[0143] Here, the first solder ball is located on the electrode of the driver chip and is used to electrically lead out the driver chip; the second solder ball is located on the electrode of the transimpedance amplifier chip and is used to electrically lead out the transimpedance amplifier chip.

[0144] In some embodiments, forming the first semiconductor structure further includes: forming a second waveguide structure located in the dielectric layer; wherein the orthographic projections of the first waveguide structure and the second waveguide structure on the first substrate at least partially overlap.

[0145] Here, a portion of the second waveguide structure can be located below the first waveguide structure, and after the optical signal is input into the second waveguide structure, it can be coupled to the first waveguide structure and then coupled to the modulator; and another portion of the second waveguide structure can be located above the photodetector, and after the optical signal is input into the second waveguide structure, it can also be coupled to the photodetector.

[0146] In some embodiments, forming the first semiconductor structure further includes: forming a resistance unit located in the dielectric layer, and the resistance unit is located below the modulator; wherein the resistance unit is used to heat the first waveguide structure and the second waveguide structure, or the resistance unit is used to achieve impedance matching between the modulator and the first metal electrode.

[0147] Here, the resistance unit is formed to radiate the heat energy it generates outward, heating the first waveguide structure and the second waveguide structure, improving the temperature distribution near the first waveguide structure and the second waveguide structure, and then affecting the mode field distribution in the first waveguide structure and the second waveguide structure to achieve phase adjustment of the optical signal.

[0148] Here, forming the resistance unit can also be used to achieve impedance matching between the modulator and the first metal electrode to improve the modulation efficiency of the modulator.

[0149] The embodiment of the present disclosure provides an optical transceiver and a method for manufacturing the same. The optical transceiver includes: a three-dimensionally integrated first semiconductor structure and a second semiconductor structure; the first semiconductor structure includes: a photodetector, a driver chip, a first waveguide structure, a plurality of first metal electrodes and a plurality of first conductive through-hole structures; wherein the driver chip is electrically connected to the plurality of first metal electrodes through the plurality of first conductive through-hole structures; the second semiconductor structure includes: an electro-optical modulation layer, the electro-optical modulation layer covers the first waveguide structure and the plurality of first metal electrodes; wherein the electro-optical modulation layer is electrically connected to the plurality of first metal electrodes; the electro-optical modulation layer, the first waveguide structure and the plurality of first metal electrodes constitute a modulator. In the embodiment of the present disclosure, the driver chip is electrically connected to the plurality of first metal electrodes through the plurality of first conductive through-hole structures, and the integration between the driver chip and the modulator is achieved by utilizing the plurality of first conductive through-hole structures, which is conducive to reducing the loss of high-frequency signals and improving the quality of signals.

[0150] In addition, in the embodiment of the present disclosure, the first semiconductor structure includes a photodetector and a driver chip. The first waveguide structure, multiple first metal electrodes and multiple first conductive through-hole structures arranged in the first semiconductor structure and the electro-optical modulation layer arranged in the second semiconductor structure together constitute a modulator. The photodetector, modulator and chip are three-dimensionally integrated, which can not only improve the integration of the device, but also improve the signal transmission rate and bandwidth.

[0151] It should be understood that “one embodiment” or “an embodiment” mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present disclosure. Therefore, “in one embodiment” or “in an embodiment” appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present disclosure, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present disclosure. The serial numbers of the embodiments of the present disclosure are for description only and do not represent the advantages and disadvantages of the embodiments.

[0152] The above description is only a preferred embodiment of the present disclosure and does not limit the patent scope of the present disclosure. All equivalent structural transformations made by using the contents of the present disclosure and the drawings under the inventive concept of the present disclosure, or direct / indirect application in other related technical fields are included in the patent protection scope of the present disclosure.

Claims

1. An optical transceiver, characterized in that: The optical transceiver includes: a first semiconductor structure and a second semiconductor structure that are three-dimensionally integrated; The first semiconductor structure includes: a photodetector, a driver chip, a first waveguide structure, a plurality of first metal electrodes, and a plurality of first conductive via structures; wherein the driver chip is electrically connected to the plurality of first metal electrodes through the plurality of first conductive via structures; and a surface of the first metal electrode is flush with a surface of the first waveguide structure; The second semiconductor structure includes: an electro-optical modulation layer, which covers the first waveguide structure and the plurality of first metal electrodes; wherein the electro-optical modulation layer is electrically connected to the plurality of first metal electrodes; the electro-optical modulation layer, the first waveguide structure and the plurality of first metal electrodes constitute a modulator.

2. The optical transceiver according to claim 1, wherein: The first semiconductor structure and the second semiconductor structure are connected by flip-chip bonding.

3. The optical transceiver according to claim 1, wherein: The driving chip is formed on a first substrate; the photodetector, the first waveguide structure and the plurality of first metal electrodes are formed on silicon-on-insulator (SOI); The SOI is located on the driver chip.

4. The optical transceiver according to claim 3, wherein: The first semiconductor structure further includes: a dielectric layer located on the SOI; wherein the first conductive via structure sequentially penetrates the dielectric layer and the SOI.

5. The optical transceiver according to claim 3, wherein: The photodetector comprises: Silicon layer; wherein the SOI includes a bottom silicon layer, a buried oxide layer and a top silicon layer in sequence, and the silicon layer is formed by etching the top silicon layer; a germanium absorption layer, located on the silicon layer; An N-type doping structure and a P-type doping structure are located on the buried oxide layer; the silicon layer and the germanium absorption layer are located between the N-type doping structure and the P-type doping structure; two second metal electrodes, the two second metal electrodes being respectively located on the N-type doped structure and the P-type doped structure; Two second conductive through-hole structures are electrically connected to the two second metal electrodes respectively.

6. The optical transceiver according to claim 5, wherein: The first semiconductor structure further includes: A transimpedance amplifier chip is formed on the first substrate, and the transimpedance amplifier chip is electrically connected to the two second metal electrodes through two second conductive through-hole structures.

7. The optical transceiver according to claim 6, wherein: The first semiconductor structure further includes: a first solder ball, wherein the first conductive through-hole structure and the driver chip are electrically connected via the first solder ball; A second solder ball is provided, and the second conductive via structure and the transimpedance amplifier chip are electrically connected via the second solder ball.

8. The optical transceiver according to claim 4, wherein: The first semiconductor structure further includes: The second waveguide structure is located in the dielectric layer; wherein the orthographic projections of the first waveguide structure and the second waveguide structure on the first substrate at least partially overlap.

9. The optical transceiver according to claim 8, wherein: The first semiconductor structure further includes: A resistance unit is located in the dielectric layer and below the modulator; wherein the resistance unit is used to heat the first waveguide structure and the second waveguide structure, or the resistance unit is used to achieve impedance matching between the modulator and the first metal electrode.

10. The optical transceiver according to claim 1, wherein: Along the transmission direction of the optical signal, the first waveguide structure includes: an optical splitter, an optical combiner and a dual-path waveguide structure located between the optical splitter and the optical combiner; wherein, the optical beam splitter splits the input light and couples the light into the electro-optical modulation layer through the dual-path waveguide structure respectively, and the light modulated by the electro-optical modulation layer is then coupled into the dual-path waveguide structure, and is output after interference through the optical combiner.

11. The optical transceiver according to claim 1, wherein: The material of the electro-optical modulation layer is lithium niobate.

12. A method for manufacturing an optical transceiver, characterized in that: The optical transceiver includes: a first semiconductor structure and a second semiconductor structure that are three-dimensionally integrated; and the manufacturing method includes: Forming the first semiconductor structure includes: providing a first substrate; forming a photodetector and a driver chip on the first substrate; forming a dielectric layer on the photodetector and the driver chip; forming a plurality of first conductive via structures, a plurality of first metal electrodes, and a first waveguide structure in the dielectric layer, wherein the surfaces of the first metal electrodes are flush with the surfaces of the first waveguide structure; and electrically connecting the driver chip to the plurality of first metal electrodes through the plurality of first conductive via structures. Forming the second semiconductor structure includes: providing a second substrate; forming an electro-optical modulation layer on the second substrate; The second semiconductor structure is flip-chip bonded to the first semiconductor structure so that the electro-optical modulation layer covers the first waveguide structure and the plurality of first metal electrodes; wherein the electro-optical modulation layer is electrically connected to the plurality of first metal electrodes; the electro-optical modulation layer, the first waveguide structure and the plurality of first metal electrodes constitute a modulator.

13. The method for manufacturing an optical transceiver according to claim 12, wherein: The step of forming a photodetector and a driver chip on the first substrate includes: forming a transimpedance amplifier chip and a driver chip on the first substrate; forming a silicon-on-insulator (SOI) on the transimpedance amplifier chip and the driver chip; wherein the SOI sequentially comprises a bottom silicon layer, a buried oxide layer, and a top silicon layer; The photodetector is formed on the SOI.

14. The method for manufacturing an optical transceiver according to claim 13, wherein: The step of forming the photodetector on the SOI layer comprises: etching the top silicon layer to form a silicon layer; forming an N-type doping structure and a P-type doping structure on the buried oxide layer, wherein the silicon layer is located between the N-type doping structure and the P-type doping structure; forming two second conductive via structures and two second metal electrodes, wherein the two second metal electrodes are in contact with the N-type doped structure and the P-type doped structure respectively; and the two second conductive via structures are electrically connected to the two second metal electrodes respectively; A germanium absorption layer is formed on the silicon layer, and the germanium absorption layer is located between the two second metal electrodes.

15. The method for manufacturing an optical transceiver according to claim 14, wherein: The forming of a plurality of first conductive via structures in the dielectric layer comprises: forming a first dielectric layer on the photodetector and the driver chip; Etching to form a plurality of first through holes that sequentially penetrate the first dielectric layer, the buried oxide layer, and the bottom silicon layer; A conductive material is filled in the first through holes to form a plurality of first conductive through hole structures.

16. The method for manufacturing an optical transceiver according to claim 15, wherein: A plurality of first metal electrodes are formed in the dielectric layer, including: forming a second dielectric layer on the plurality of first conductive via structures; Etching the second dielectric layer to form a plurality of first grooves, wherein each of the first grooves exposes the first conductive through-hole structure; A metal material is filled in the first grooves to form a plurality of first metal electrodes.

17. The method for manufacturing an optical transceiver according to claim 16, wherein: forming a first waveguide structure in the dielectric layer, comprising: etching the second dielectric layer to form a plurality of first grooves while etching the second dielectric layer to form a second groove; The second groove is filled with a waveguide material to form a first waveguide structure.

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