Chips and optical communication devices

Abstract

The embodiments of the present application disclose a chip and an optical communication device. The chip may include a substrate, an insulating layer located on a side of the substrate, and a first waveguide and a second waveguide in the insulating layer. The second waveguide is located on a side of the first waveguide away from the substrate. The first waveguide has an electro-optic effect. The transmission loss of the second waveguide is smaller than the transmission loss of the first waveguide. In this manner, the first waveguide may be used as a part of an active component, and the first waveguide may be used for electro-optic modulation. The second waveguide may be used as a passive component, and the second waveguide is used to transmit an optical signal. The first coupling portion of the first waveguide and the second coupling portion of the second waveguide form a first coupling structure, and the first coupling structure is configured to realize optical coupling between the first waveguide and the second waveguide. Therefore, by using the first waveguide and the second waveguide, active components and passive components can be integrated, and the chip obtained after integration has better transmission characteristics and can realize electro-optical modulation, thereby further improving the performance of the optical communication system.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular, to chips and optical communication devices.

Background Art

[0002] With the development of optical communication, more functions are required for optical communication systems. Some passive components and active components need to be arranged in the optical communication system to adapt to more scenarios. The passive component can be, for example, a waveguide. The active component can be, for example, an electro-optic modulator and a photodetector. As the pressure to improve the performance of the network increases and the requirement for reducing green emissions increases, operators need to suppress energy consumption and improve the performance of the network at a low cost. Combining passive components and active components on one chip to achieve photonic integration is an inevitable trend. The chip for realizing photonic integration can be Sending and receiving are integrated. applied to scenarios such as high-bitrate communication. However, high-performance passive components require relatively small losses in the waveguide, and active components also have special requirements for the waveguide or optoelectronic materials due to the special requirements of the active components. For example, an electro-optic modulator requires a waveguide with an electro-optic effect, and a photodetector requires a light-absorbing material with light-electric conversion characteristics. Currently, it is not possible to integrate active components with small losses and passive components on the same chip.

Summary of the Invention

[0003] In view of this, a first aspect of this application provides a chip and an optical communication device in which active components with small losses and passive components are integrated on the same chip.

Means for Solving the Problems

[0004] According to a first aspect of the embodiments of this application, a chip is provided. The chip may include a substrate, an insulating layer located on the side of the substrate, and a first waveguide and a second waveguide located within the insulating layer. The second waveguide is located on the side of the first waveguide away from the substrate. The first waveguide has an electro-optic effect. The transmission loss of the second waveguide is less than that of the first waveguide. In this way, the first waveguide may be used as part of an active component, and the first waveguide may be used for electro-optic modulation. The second waveguide may be used as a passive component, and the second waveguide may be used to transmit an optical signal. In this way, a passive component with low loss can be realized. A first coupling portion of the first waveguide and a second coupling portion of the second waveguide form a first coupling structure, the first coupling structure is configured to realize optical coupling between the first waveguide and the second waveguide. Therefore, active and passive components can be integrated using the first and second waveguides, and the passive components in the resulting chip will have better transmission characteristics, while the active components will be able to achieve electro-optical modulation. Compared to chips containing only the first waveguide or only the second waveguide, the resulting chip can have lower losses and a wider range of functions, expanding the application scenarios of the chip and improving the performance of optical communication systems, including optical chips, to some extent.

[0005] In some possible implementations, the material of the first waveguide is silicon, and the material of the second waveguide is silicon nitride.

[0006] In this embodiment of the present application, the material of the first waveguide may be silicon, and the first waveguide and insulating layer form a silicon-on-insulator (SOI) structure that is compatible with complementary metal oxide semiconductor (CMOS) processes. The material of the second waveguide may be silicon nitride, which has relatively low transmission loss and integrates high-performance active components with low-loss passive components.

[0007] In some possible implementations, the chip is, A third waveguide in an insulating layer, located on the side of the second waveguide away from the substrate, wherein the electro-optic modulation efficiency of the third waveguide is higher than that of the first waveguide, and the fifth coupling of the first waveguide, the sixth coupling of the second waveguide, and the seventh coupling of the third waveguide form a third coupling structure, the third coupling structure is configured to realize optical coupling between the second waveguide and the third waveguide. It also includes.

[0008] In this embodiment of the present application, the chip further includes a third waveguide. The electro-optic modulation efficiency of the third waveguide is higher than that of the first waveguide. The third waveguide can be coupled to the second waveguide. Therefore, by using the third waveguide, a modulator with a higher electro-optic modulation efficiency can be obtained, satisfying a wider range of application scenarios.

[0009] In some possible implementations, the material for the third waveguide is lithium niobate, indium phosphide, or tantalum niobate.

[0010] In this embodiment of the present application, the material of the third waveguide may be lithium niobate, indium phosphide, or tantalum niobate, which can be adapted to a wider range of scenarios while having higher electro-optic modulation efficiency.

[0011] In some possible implementations, the chip is, The first electrode pair located on both sides of the third waveguide in the insulating layer It also includes.

[0012] In this embodiment of the present application, a first electrode pair may be provided on both sides of a third waveguide. The first electrode pair is configured to generate a first modulating electric field for modulating an optical signal within the third waveguide, thereby satisfying optical communication requirements.

[0013] In some possible implementations, the thickness of the insulating layer between the second waveguide and the third waveguide is in the range of [200 nm, 550 nm].

[0014] In this embodiment of the present application, the coupling efficiency between the second waveguide and the third waveguide can be increased because the thickness of the insulating layer between the second waveguide and the third waveguide is within an appropriate range.

[0015] In some possible implementations, the chip is, A photoelectric detector in an insulating layer, wherein the photoelectric detector is connected to an interlayer interconnection structure using a doping structure, the doping structure is a semiconductor layer having doping elements, the material of the semiconductor layer matches the material of the first waveguide, and the distance between the doping structure and the substrate matches the distance between the first waveguide and the substrate. It also includes.

[0016] In this embodiment of the present application, the chip further includes a photoelectric detector. The photoelectric detector may be connected to a doping structure, which is a semiconductor layer having a doping element. The material of the semiconductor layer is the same as the material of the first waveguide, and the semiconductor layer and the first waveguide are located in the same layer. In this way, the semiconductor structure and the first waveguide can be obtained by etching the same film layer, simplifying the process.

[0017] In some possible implementations, the distance between the surface of the photoelectric detector away from the substrate and the surface of the substrate is smaller than the distance between the surface of the second waveguide away from the substrate and the surface of the substrate.

[0018] In this embodiment of the present application, the upper surface of the photoelectric detector may be lower than the upper surface of the second waveguide so that the manufacturing of the photoelectric detector and the manufacturing of the second waveguide do not affect each other. For example, the influence on the photoelectric detector due to the use of the second waveguide as a stop layer is avoided.

[0019] In some possible implementation forms, the range of the size of the photodetector in the direction perpendicular to the surface of the substrate is [200 nm, 350 nm].

[0020] In this embodiment of the present application, the photodetector can have an appropriate thickness and is compatible with other components while ensuring optical detection characteristics.

[0021] In some possible implementation forms, the chip is a laser diode located on the substrate side, and the material of the laser diode includes a group III-V compound, the laser diode further includes.

[0022] In this embodiment of the present application, the chip can further include a laser diode for implementing a light-emitting function in the chip, satisfying more application scenarios.

[0023] In some possible implementation forms, the chip laser is a semiconductor optical amplifier configured to amplify the light emitted by the diode, and the material of the semiconductor optical amplifier includes a group III-V compound, the semiconductor optical amplifier further includes.

[0024] In this embodiment of the present application, the chip further includes a semiconductor optical amplifier for amplifying the optical signal in the chip, satisfying more application scenarios.

[0025] In some possible implementation forms, the chip further includes a second pair of electrodes located on both sides of the first waveguide in the insulating layer further includes.

[0026] In this embodiment of the present application, a second pair of electrodes may be provided on both sides of the first waveguide. The second pair of electrodes is configured to generate a second modulation electric field for modulating the optical signal in the first waveguide, satisfying optical communication requirements.

[0027] In some possible implementations, the hydrogen content in the silicon nitride material of the second waveguide is 10% or less.

[0028] In this embodiment of the present application, the hydrogen content in the silicon nitride material of the second waveguide is within a suitable range for controlling the transmission loss of the second waveguide.

[0029] In some possible implementations, the transmission loss of the second waveguide is 0.5 dB / cm or less.

[0030] In this embodiment of the present application, the transmission loss of the second waveguide is relatively small in order to improve energy utilization.

[0031] In some possible implementation configurations, the size range of the second waveguide in the direction perpendicular to the substrate surface is [300 nm, 400 nm].

[0032] In this embodiment of the present application, the thickness of the second waveguide is within a suitable range so that the second waveguide can be interchangeable with other components while having relatively low transmission loss.

[0033] In some possible implementation configurations, the size range of the insulating layer between the first waveguide and the second waveguide in the direction perpendicular to the substrate surface is [40 nm, 100 nm].

[0034] In this embodiment of the present application, the insulating layer between the first waveguide and the second waveguide has an appropriate thickness to ensure relatively high optical coupling efficiency between the first waveguide and the second waveguide, and to enable ion implantation through the insulating layer when it is necessary to perform ion implantation at the same layer location as the first waveguide.

[0035] According to a second embodiment of the present application, an optical communication device is provided. The device includes a chip according to a first embodiment of the present application.

[0036] According to the aforementioned technical solution, the embodiments of this application have the following advantages.

[0037] Embodiments of this application provide a chip and an optical communication device. The chip may include a substrate, an insulating layer located on the side of the substrate, and a first waveguide and a second waveguide located within the insulating layer. The second waveguide is located on the side of the first waveguide away from the substrate. The first waveguide has an electro-optic effect. The transmission loss of the second waveguide is less than that of the first waveguide. In this way, the first waveguide may be used as part of an active component, and the first waveguide may be used for electro-optic modulation. The second waveguide may be used as a passive component, and the second waveguide may be used to transmit an optical signal. In this way, a passive component with low loss can be realized. A first coupling portion of the first waveguide and a second coupling portion of the second waveguide form a first coupling structure, and the first coupling structure is configured to realize optical coupling between the first waveguide and the second waveguide. Therefore, active and passive components can be integrated using the first and second waveguides, and the passive components in the resulting chip will have better transmission characteristics, while the active components will be able to achieve electro-optical modulation. Compared to chips containing only the first waveguide or only the second waveguide, the resulting chip can have lower losses and a wider range of functions, expanding the application scenarios of the chip and improving the performance of optical communication systems, including optical chips, to some extent.

[0038] To clearly understand the specific implementations of this application, the following is a brief description of the accompanying drawings used to illustrate the specific implementations of this application. Clearly, the accompanying drawings only illustrate some of the embodiments of this application. [Brief explanation of the drawing]

[0039] [Figure 1] This is a schematic top view of a chip according to one embodiment of the present application. [Figure 2] Figure 1 is a cross-sectional view of the chip along the AA direction. [Figure 3] This is a top view of another chip according to one embodiment of the present application. [Figure 4] Figure 3 is a cross-sectional view of the chip along the BB direction. [Figure 5] This is a cross-sectional view of a chip according to one embodiment of the present application. [Figure 6] This is a top view of another chip according to one embodiment of the present application. [Figure 7] Figure 6 is a cross-sectional view of the chip along the AA direction. [Figure 8] This is a top view of another chip according to one embodiment of the present application. [Figure 9] Figure 8 is a cross-sectional view of the chip along the BB direction. [Figure 10] This is a cross-sectional view of another chip according to one embodiment of this application. [Figure 11] This is a cross-sectional view of yet another chip according to one embodiment of the present application. [Figure 12] This is a cross-sectional view of yet another chip according to one embodiment of the present application. [Figure 13] This is a cross-sectional view of yet another chip according to one embodiment of the present application. [Figure 14] This is a schematic diagram of the structure of an optical communication system according to one embodiment of this application. [Modes for carrying out the invention]

[0040] Embodiments of this application provide a chip and an optical communication device in which low-loss active and passive components are integrated on the same chip.

[0041] In the specification, claims, and accompanying drawings of this application, terms such as “first,” “second,” “third,” “fourth,” etc. (if any) are intended to distinguish similar subjects and do not necessarily indicate a specific order or sequence. Subjects referred to in this manner are interchangeable in appropriate contexts, and it should be understood that the embodiments described herein may be implemented in an order other than that illustrated or described herein. In addition, “include,” “have,” and any other variations are intended to include subjects in a non-exclusive manner. For example, a process, method, system, product or device that includes an enumeration of steps or parts is not necessarily limited to the explicitly enumerated steps or parts and may include other steps or parts that are not explicitly enumerated or are not specific to the process, method, product or device.

[0042] This application will be described in detail with reference to schematic diagrams. Examples of the present application For the sake of clarity, the cross-sectional views of the constituent structures are not partially enlarged according to general proportions, and the schematic diagrams are merely examples and do not limit the scope of protection of this application. Furthermore, the length, width, and depth of the three-dimensional space should be included in the actual manufacturing.

[0043] With the advancement of optical communication, optical communication systems are required to have more functions. Several passive and active components need to be placed within the optical communication system to adapt to a wider range of scenarios. Passive components may be, for example, waveguides. Active components may be, for example, electro-optic modulators and photoelectric detectors. Since passive and active components are formed on the same chip, the chip is, Sending and receiving are integrated. This can be applied to scenarios such as high-baud rate communication.

[0044] However, current chips, which integrate multiple functional components, are based on a single material platform. High-performance passive components require waveguides with relatively low losses, and active components also have specific requirements regarding waveguides or photoelectric materials due to the specific requirements of the active components. For example, an electro-optic modulator requires a waveguide with electro-optic effects, and a photoelectric detector requires a light-absorbing material with photoelectric conversion properties. A single material cannot easily satisfy the requirements of different components. For example, an SOI chip based on silicon-on-insulator (SOI) can integrate passive components with several active components. Active components may include modulators, detectors, etc., to realize receiving and transmitting functions in a single device. However, waveguides in SOI chips have problems such as high transmission loss, high reflection, low process tolerance, high dispersion, and temperature sensitivity, making them unsuitable for temperature-insensitive multiplexers / demultiplexers (MUX / DeMux). In the case of integrated components based on a SiN platform, multiple SiN passive waveguide components, such as grating couplers and beam splitting coupling structures, can be mounted on a single chip. In addition, SiN passive waveguide structures are temperature insensitive, which helps in obtaining temperature-insensitive Mux / DeMux structures with low loss and low dispersion. However, integrating active components using SiN platform-based integrated chips is challenging.

[0045] Therefore, currently, in the case of chips with a single material platform, low-loss active and passive components cannot be integrated within the same chip.

[0046] Based on the technical problems described above, embodiments of this application provide a chip and an optical communication device. The chip may include a substrate, an insulating layer located on the side of the substrate, and a first waveguide and a second waveguide located within the insulating layer. The second waveguide is located on the side of the first waveguide away from the substrate. The first waveguide has an electro-optic effect. The transmission loss of the second waveguide is less than that of the first waveguide. In this way, the first waveguide may be used as part of an active component, and the first waveguide may be used for electro-optic modulation. The second waveguide may be used as a passive component, and the second waveguide may be used to transmit an optical signal. In this way, a passive component with low loss can be realized. A first coupling portion of the first waveguide and a second coupling portion of the second waveguide form a first coupling structure, which is configured to realize optical coupling between the first waveguide and the second waveguide. Therefore, active and passive components can be integrated using the first and second waveguides, and the passive components in the resulting chip will have better transmission characteristics, while the active components will be able to achieve electro-optical modulation. Compared to chips containing only the first waveguide or only the second waveguide, the resulting chip can have lower losses and a wider range of functions, expanding the application scenarios of the chip and improving the performance of optical communication systems, including optical chips, to some extent.

[0047] To make the purpose, features, and advantages of this application clearer and easier to understand, the following describes in detail a specific implementation of this application with reference to the attached drawings.

[0048] Figure 1 is a schematic top view of a chip according to one embodiment of the present application. Figure 2 is a cross-sectional view of the chip of Figure 1 along the AA direction. The chip includes a substrate 10, an insulating layer 100 located on one side of the substrate 10, and a first waveguide 11 and a second waveguide 12 located within the insulating layer 100.

[0049] In this embodiment of the present application, the chip may include a substrate 10. The substrate 10 is configured to support a device structure on the substrate 10. The substrate 10 may be a semiconductor substrate, for example, a Si substrate, a Ge substrate, a SiGe substrate, a silicon-on-insulator (SOI) substrate, a germanium-on-insulator (GOI) substrate, or a silicon-and-germanium-on-insulator (SGOI) substrate. In another embodiment, the semiconductor substrate may alternatively be a substrate of another device semiconductor or a compound semiconductor, such as GaAs, InP, or SiC. In this embodiment of the present application, the material of the substrate 10 may be silicon.

[0050] The insulating layer 100 may be located on one side of the substrate 10. The first waveguide 11 and the second waveguide 12 are located within the insulating layer 100. The insulating layer 100 can insulate the first waveguide 11 from the substrate 10 and also insulate the second waveguide 12 from the substrate 10. The first waveguide 11 and the second waveguide 12 are used as waveguide core layers. The insulating layer 100 may also be used as a waveguide coating layer. The refractive index of the insulating layer 100 is smaller than that of the first waveguide 11 and smaller than that of the second waveguide 12, so that the optical signal is restricted in the first waveguide 11 and the second waveguide 12. The insulating layer 100 may contain a single material or may be a composite layer containing multiple film layers of different materials. The material of the insulating layer 100 may be, for example, silicon oxide, or of course, other insulating materials.

[0051] For the sake of clarity, the direction from the substrate 10 towards the insulating layer 100 may be referred to as "up," the direction from the insulating layer 100 towards the substrate 10 as "down," and the direction perpendicular to the surface of the substrate 10 as the longitudinal direction. However, such markings are for convenience only and are unrelated to the direction of gravity.

[0052] In this embodiment of the present application, the material of the first waveguide 11 is different from the material of the second waveguide 12, and as a result, the first waveguide 11 and the second waveguide 12 have different properties. The first waveguide 11 may have an electro-optic effect, specifically, the refractive index of the first waveguide 11 may change with the applied electric field. Therefore, the first waveguide 11 may be used as part of an active component, and the first waveguide 11 may be used for electro-optic modulation. The transmission loss of the second waveguide 12 is smaller than that of the first waveguide 11. Therefore, the second waveguide 12 may be used as a passive component, and an optical signal may be transmitted using the second waveguide 12. In this way, a passive component with low loss is realized. Passive and active components can be integrated using the first waveguide 11 and the second waveguide 12. Furthermore, in the integrated chip, the passive components exhibit superior transmission characteristics, while the active components enable electro-optic modulation. Compared to a chip containing only the first waveguide, the integrated chip has lower transmission loss. Compared to a chip containing only the second waveguide, the integrated chip has electro-optic modulation capabilities. Therefore, the integrated chip can have lower losses and a wider range of functions, expanding the application scenarios for the chip.

[0053] Specifically, the second waveguide 12 may be located on the side of the first waveguide 11 away from the substrate 10. More specifically, the second waveguide 12 is located above the first substrate 10, and the second waveguide 12 and the first waveguide 11 are stacked vertically. The first coupling portion of the first waveguide 11 and the second coupling portion of the second waveguide 12 constitute a first coupling structure 1001. The first coupling structure 1001 is configured to realize optical coupling between the first waveguide 11 and the second waveguide 12. In this way, optical signals can be transmitted between the first waveguide 11 and the second waveguide 12. In regions where electro-optic modulation is required, optical signals are transmitted using the first waveguide 11, and in regions where electro-optic modulation is not required, optical signals are transmitted using the second waveguide 12. Therefore, the chip has electro-optic modulation functionality while having lower transmission loss, improving the performance of the chip.

[0054] The optical coupling method between the first waveguide 11 and the second waveguide 12 may be evanescent wave coupling. The size range of the insulating layer 100 between the first waveguide 11 and the second waveguide 12 in the direction perpendicular to the surface of the substrate 10 is [40 nm, 100 nm], in other words, the distance range between the top surface of the first waveguide 11 and the bottom surface of the second waveguide 12 is [40 nm, 100 nm], so the optical coupling efficiency between the first waveguide 11 and the second waveguide 12 is relatively high. In specific implementation, the size range of the second waveguide 12 in the direction perpendicular to the surface of the substrate 10 is [300 nm, 400 nm], and the transmission loss of the second waveguide 12 is 0.5 dB / cm or less.

[0055] For example, the material of the first waveguide 11 is silicon. The insulating layer 100 between the first waveguide 11 and the substrate 10 and the first waveguide 11 form an SOI structure. SOI optical waveguide technology has excellent optical performance and can be fully compatible with mature silicon-based complementary metal oxide semiconductor (CMOS) processes. Therefore, by integrating the second waveguide 12 on the SOI platform, optical performance can be improved and chip integration density can also be increased. The material of the second waveguide 12 may be silicon nitride. The hydrogen content in the silicon nitride material of the second waveguide 12 may be 10% or less.

[0056] In this embodiment of the present application, a second pair of electrodes 111 may be provided on both sides of the first waveguide 11. The second pair of electrodes 111 is located within the insulating layer 100. When different voltages are applied, the second pair of electrodes 111 can supply a second modulating electric field for modulating the optical signal in the first waveguide 11. Figure 3 is a top view of another chip according to one embodiment of the present application. Figure 4 is a cross-sectional view of the chip of Figure 3 along the BB direction. The second pair of electrodes 111 and the first waveguide 11 may be arranged in a direction parallel to the surface of the substrate 10. The second modulating electric field between the second pair of electrodes 111 may be parallel to the surface of the substrate 10.

[0057] The second electrode pair 111 can be led out around the insulating layer via an interlayer wiring structure 112. The interlayer wiring structure 112 may include conductor columns, or may include conductor columns and conductor pads. Multiple conductor columns and multiple conductor pads may be present. Conductor columns may be arranged between conductor pads of neighboring layers. Conductor columns are arranged in through-holes that extend vertically in the insulating layer 100. By arranging multiple conductor pads, the through-holes that penetrate vertically through the insulating layer are divided into multiple through-holes, reducing the depth of each through-hole and the depth-to-width ratio of each through-hole, thereby reducing the etching difficulty and improving the reliability of the interlayer wiring structure 112.

[0058] In this embodiment of the present application, the cross-sectional view of the chip in direction AA has a first coupling structure 1001, and the cross-sectional view of the chip in direction BB has a modulator based on a first waveguide 11. In practice, the first coupling structure 1001 and the modulator based on the first waveguide 11 can coexist within the same chip. Furthermore, the first coupling structure 1001 and the modulator based on the first waveguide 11 can coexist in a cross-sectional view along a nonlinear direction. Figure 5 is a cross-sectional view of a chip according to one embodiment of the present application. Note that the schematic diagram in Figure 5 shows that the first coupling structure 1001 and the modulator based on the first waveguide 11 coexist within the same chip, and the arrangement direction of the first coupling structure 1001 and the modulator based on the first waveguide 11 is not emphasized.

[0059] Specifically, the chip further includes an optical splitter (not shown) for forming a Mach-Zehnder interferometer (MZI) structure together with the first waveguide 11. structureThe system includes a 1×2 beam splitter, two modulation waveguides, and a 2×1 beam combiner. The optical signal is split into two parts using the 1×2 beam splitter, and the two parts are directed to the optical paths of the two arms of the MZI structure, respectively. Each of the two arms of the MZI structure is provided with a modulation waveguide. Electrodes are provided on both sides of the modulation waveguide. The modulation waveguide can change the phase of the optical signal of the arm under the action of an electric field. The optical signals of the two arms of the MZI structure are then combined using a 2×1 beam combiner. Because the optical signals of the two arms interfere with each other, the characteristics of the combined optical signal change with respect to the characteristics of the input optical signal. For example, the optical intensity or optical phase changes. The modulation waveguide of at least one arm may be the first waveguide 11 described above, and is used to adjust the optical phase under the action of an electric field and further change the intensity or phase of the output optical signal.

[0060] In this embodiment of the present application, the chip further includes a third waveguide 13 within the insulating layer 100. Figure 6 is a top view of another chip according to one embodiment of the present application. Figure 7 is a cross-sectional view of the chip of Figure 6 along the AA direction. The electro-optic modulation efficiency of the third waveguide 13 is higher than that of the first waveguide 11. Thus, the third waveguide 13 may be used as part of an active component, or it may be used for electro-optic modulation. In addition, the third waveguide 13 has a relatively high modulation efficiency, which helps to improve the overall modulation efficiency of the chip.

[0061] The third waveguide 13 is located on the side of the second waveguide 12 away from the substrate 10, i.e., above the second waveguide 12. The third coupling of the first waveguide 11 and the fourth coupling of the third waveguide 13 can form a second coupling structure for realizing optical coupling between the first waveguide 11 and the third waveguide 13. In this way, optical signals can be transmitted between the first waveguide 11 and the third waveguide 13, enabling higher modulation efficiency of the modulator using the third waveguide 13 and further improving the performance of the chip. The optical coupling between the first waveguide 11 and the third waveguide 13 may be evanescent wave coupling.

[0062] The third waveguide 13 is located on the side of the second waveguide 12 away from the substrate 10, i.e., above the second waveguide 12. The fifth coupling of the first waveguide 11, the sixth coupling of the second waveguide 12, and the seventh coupling of the third waveguide 13 constitute the third coupling structure 1002. The third coupling structure 1002 is configured to realize optical coupling between the second waveguide 12 and the third waveguide 13. In this way, optical signals can be transmitted between the second waveguide 12 and the third waveguide 13, enabling higher modulation efficiency of the modulator using the third waveguide 13 and further improving the performance of the chip. The optical coupling between the second waveguide 12 and the third waveguide 13 may be evanescent wave coupling, and is achieved by evanescent wave coupling between the fifth coupling, the sixth coupling, and the seventh coupling.

[0063] Specifically, the thickness range of the insulating layer 100 between the second waveguide 12 and the third waveguide 13 is [200 nm, 550 nm] to achieve relatively high optical coupling efficiency between the second waveguide 12 and the third waveguide 13. For example, the material of the third waveguide 13 may be lithium niobate (thin film lithium niobate, TFLN), indium phosphide (InP), or tantalum niobate.

[0064] In this embodiment of the present application, a first electrode pair 131 may be further provided on both sides of the third waveguide 13. The first electrode pair 131 is located within the insulating layer 100. When different voltages are applied, the first electrode pair 131 will be A first modulating electric field can be supplied to modulate the optical signal in the third waveguide 13. Figure 8 is a top view of another chip according to one embodiment of the present application. Figure 9 is a cross-sectional view of the chip of Figure 8 along the BB direction. The first electrode pair 131 and the third waveguide 13 may be arranged in a direction parallel to the surface of the substrate 10. The first modulating electric field between the first electrode pair 131 may be parallel to the surface of the substrate 10.

[0065] The first electrode pair 131 can be led out to the periphery of the insulating layer via an interlayer wiring structure 132. The interlayer wiring structure 132 may include conductor columns, or may include conductor columns and conductor pads. Multiple conductor columns and multiple conductor pads may be present. Conductor columns may be arranged between conductor pads of neighboring layers. Conductor columns are arranged in through-holes that extend vertically in the insulating layer 100. By arranging multiple conductor pads, the through-holes that penetrate vertically through the insulating layer are divided into multiple through-holes, reducing the depth of each through-hole and the depth-to-width ratio of each through-hole, thereby reducing the etching difficulty and improving the reliability of the interlayer wiring structure 132.

[0066] In this embodiment of the present application, the cross-sectional view of the chip in direction AA has a third coupling structure 1002, and the cross-sectional view of the chip in direction BB has a modulator based on a third waveguide 13. In practice, the third coupling structure 1002 and the modulator based on the third waveguide 13 can coexist within the same chip. Furthermore, the third coupling structure 1002 and the modulator based on the third waveguide 13 can coexist in a cross-sectional view along a nonlinear direction. Figure 10 is a cross-sectional view of a chip according to one embodiment of the present application. Note that the schematic diagram in Figure 10 shows that the third coupling structure 1002 and the modulator based on the third waveguide 13 coexist within the same chip, and the arrangement direction of the third coupling structure 1002 and the modulator based on the third waveguide 13 is not emphasized.

[0067] Specifically, the chip further includes an optical splitter (not shown) for forming an MZI structure together with a third waveguide 13. The modulation waveguide of at least one arm in the MZI structure may be the aforementioned third waveguide 13, which is used to adjust the optical phase under the action of an electric field and to further modify the intensity or phase of the output optical signal.

[0068] In this embodiment of the present application, the insulating layer 100 may further comprise a photodetector (PD) 14. The photodetector 14 can detect an optical signal and form an electrical signal based on the detected optical signal. Figures 10, 11, 12, and 13 are cross-sectional views of a plurality of chips according to one embodiment of the present application. These figures do not emphasize the orientation of the components. In Figure 10, a first coupling structure 1001 and a photodetector 14 coexist within the same chip. In Figure 11, a first coupling structure 1001, a modulator based on a first waveguide 11, and a photodetector 14 coexist. In Figure 12, a third coupling structure 1002 and a photodetector 14 coexist. In Figure 13, a third coupling structure 1002, a modulator based on a first waveguide 11, a modulator based on a third waveguide 13, and a photodetector 14 coexist. The material of the photoelectric detector 14 may include germanium, etc. The size range of the photoelectric detector 14 in the direction perpendicular to the surface of the substrate 10 is [200 nm, 350 nm].

[0069] The photoelectric detector 14 is drawn out of the insulating layer 100 via the interlayer interconnection structure 142, allowing the generated electrical signal to be drawn out of the insulating layer 100. The interlayer wiring structure 142 may include conductor columns, or may include conductor columns and conductor pads. Multiple conductor columns and multiple conductor pads may be present. Conductor columns may be arranged between conductor pads of neighboring layers. Conductor columns are arranged in through holes extending vertically in the insulating layer 100. By arranging multiple conductor pads, the through holes penetrating vertically through the insulating layer are divided into multiple through holes, reducing the depth of each through hole and the depth-to-width ratio of each through hole, thereby reducing the etching difficulty and improving the reliability of the interlayer wiring structure 142.

[0070] Specifically, the photoelectric detector 14 can be connected to the interlayer interconnection structure 142 via a doping structure 141. As shown in Figures 10 to 13, the doping structure 141 may be a semiconductor layer having a doping element. The doping structure 141 makes good contact with the photoelectric detector 14 and the interlayer interconnection structure 142, reducing contact loss of electrical signals. The material of the semiconductor layer may be the same as the material of the first waveguide 11, and the semiconductor layer and the first waveguide 11 may be located on the same layer, in other words, the distance between the doping structure 141 and the substrate 10 is the same as the distance between the first waveguide 11 and the substrate 10. In this way, the semiconductor layer and the first waveguide 11 can be obtained by etching the same film layer, reducing process complexity. Furthermore, by setting the thickness range of the insulating layer 100 between the first waveguide 11 and the second waveguide 12 to [40 nm, 100 nm], ion implantation into the semiconductor layer can be more effectively achieved in order to form doping elements in the semiconductor layer.

[0071] In a specific implementation configuration, the distance between the surface of the photoelectric detector 14, which is separated from the substrate 10, and the surface of the substrate 10 is smaller than the distance between the surface of the second waveguide 12, which is separated from the substrate 10, and the surface of the substrate 10. In other words, the upper surface of the photoelectric detector 14 is lower than the upper surface of the second waveguide 12. In this way, the formation of the photoelectric detector 14 and the formation of the second waveguide 12 do not affect each other. For example, a planarization process in which the second waveguide 12 is used as a stop layer does not affect the integrity of the photoelectric detector 14.

[0072] In this embodiment of the present application, the chip further includes a laser diode (LD) 15 disposed on one side of the substrate 10. As shown in Figure 13, the laser diode 15 is configured to generate optical carriers. In this way, a modulator based on a first waveguide 11 can modulate an electrical signal on a second electrode pair 111 to optical carriers in the first waveguide 11 to form an optical signal, and a modulator based on a third waveguide 13 can modulate an electrical signal on a first electrode pair 131 to optical carriers in the third waveguide 13 to form an optical signal. The material of the laser diode 15 includes a III-V compound, such as gallium nitride.

[0073] In this embodiment of the present application, the chip further includes a semiconductor optical amplifier (SOA) disposed on one side of the substrate 10. The semiconductor optical amplifier is configured to amplify light emitted by a light-emitting diode or to amplify a modulated optical signal. The material of the semiconductor optical amplifier includes a III-V compound, such as gallium nitride.

[0074] In this embodiment of the present application, at least one of the modulators based on the first waveguide 11 and the modulators based on the third waveguide 13 may be integrated based on a passive waveguide, and by integrating at least one of the photoelectric detector 14, laser diode 15, and semiconductor optical amplifier, an optical communication chip with integrated transmission and reception functions can be obtained, and an optical chip for a large-scale integrated transceiver, such as an integrated coherent transmitter and receiver (ICTR), can be realized.

[0075] This embodiment of the present application provides a chip. The chip may include a substrate, an insulating layer located on the side of the substrate, and a first waveguide and a second waveguide located within the insulating layer. The second waveguide is located on the side of the first waveguide away from the substrate. The first waveguide has an electro-optic effect. The transmission loss of the second waveguide is less than that of the first waveguide. In this way, the first waveguide may be used as part of an active component, and the first waveguide may be used for electro-optic modulation. The second waveguide may be used as a passive component, and the second waveguide may be used to transmit an optical signal. In this way, a passive component with low loss can be realized. A first coupling portion of the first waveguide and a second coupling portion of the second waveguide form a first coupling structure, which is configured to realize optical coupling between the first waveguide and the second waveguide. Therefore, active and passive components can be integrated using the first and second waveguides, and the passive components in the resulting chip will have better transmission characteristics, while the active components will be able to achieve electro-optical modulation. Compared to chips containing only the first waveguide or only the second waveguide, the resulting chip can have lower losses and a wider range of functions, expanding the application scenarios of the chip and improving the performance of optical communication systems, including optical chips, to some extent.

[0076] Based on the chip provided in the embodiments described above, one embodiment of the present application further provides an optical communication device including the chip. The optical communication device is, for example, an optical module. The optical module may be a coherent communication module, a short-range communication module, and the like. The optical module may include the aforementioned chip and a fiber array unit (FAU) configured to fix a fiber optic array, thereby facilitating connection between the aforementioned chip and the fiber optic array. The optical module and switch chip constitute an optical switch. The optical switch can be used for data exchange between servers of different layers in a large data center, improving bandwidth and reducing the extra power consumption caused by switching network cables.

[0077] Figure 14 is a schematic diagram of the structure of an optical communication system according to one embodiment of this application. One end of the chip is connected to a fiber, which is configured to transmit optical signals. The other end of the chip is connected to a conversion chip, which is configured to process and generate electrical signals.

[0078] If the chip includes a modulator, the optical communication device may be connected to an output fiber and, after modulating the optical signal to be modulated, transmit the modulated optical signal via the output fiber. The optical signal to be modulated may be supplied by using an external light source or by using an internal light-emitting component. The light-emitting component may be, for example, a laser diode.

[0079] If the chip includes a photoelectric detector, the optical communication device may be connected to an input fiber. After receiving an optical signal from the fiber, the photoelectric detector may generate a corresponding electrical signal based on the optical signal in order to process the electrical signal.

[0080] The conversion chip may include a driver module. The driver module is connected to a modulator to provide a modulation signal, which in turn modulates the optical signal to be modulated using the modulation signal, loading the modulation signal, which is used as an electrical signal, into the optical signal to be modulated. The conversion chip may further include a trans-impedance amplifier (TIA). The trans-impedance amplifier amplifies the electrical signal generated by the photoelectric detector. photoelectric It is connected to the detector.

[0081] An optical digital signal processing (oDSP) module is connected to a driver module and controls the driver module to generate a modulated signal. The oDSP module is connected to a transimpedance amplifier and can control the transimpedance amplifier to amplify the electrical signal and process the amplified electrical signal.

[0082] All embodiments described herein are explained step by step, and with respect to the same or similar parts of an embodiment, references to those embodiments may be made, and each embodiment focuses on the differences from the other embodiments.

[0083] The foregoing provides specific implementations of the present application. It should be understood that the above embodiments are merely illustrative of the technical solutions of the present application and are not intended to limit the present application. While the present application is described in detail with reference to the above embodiments, those skilled in the art will understand that modifications can be made to the technical solutions described in the above embodiments, or that some of their technical features can be replaced with equivalent alternatives, without departing from the scope of the technical solutions of the embodiments of the present application. [Explanation of symbols]

[0084] 10 circuit boards 11. First Waveguide 12. Second Waveguide 13. The third waveguide 14 Photoelectric detectors 15 Laser Diode 100 Insulating layer 111 Second electrode pair 112 Interlayer wiring structure 131 First electrode pair 132 Interlayer wiring structure 141 Doping Structure 142 Interlayer interconnection structure 1001 First bonding structure 1002 Third bonding structure

Claims

1. circuit board and An insulating layer located on one side of the aforementioned substrate, A first waveguide and a second waveguide located within the insulating layer, wherein the second waveguide is located on the side of the first waveguide away from the substrate, the first waveguide has an electro-optic effect, and the transmission loss of the second waveguide is less than that of the first waveguide. Equipped with, The first coupling portion of the first waveguide and the second coupling portion of the second waveguide form a first coupling structure, and the first coupling structure is configured to realize optical coupling between the first waveguide and the second waveguide. The third waveguide in the insulating layer further comprises a third waveguide located on the side of the second waveguide away from the substrate. It's a tip, The insulating layer is present between the first waveguide and the second waveguide. The aforementioned chip is a single chip.

2. The chip according to claim 1, wherein the material of the first waveguide is silicon and the material of the second waveguide is silicon nitride.

3. circuit board and An insulating layer located on one side of the aforementioned substrate, A first waveguide and a second waveguide located within the insulating layer, wherein the second waveguide is located on the side of the first waveguide away from the substrate, the first waveguide has an electro-optic effect, and the transmission loss of the second waveguide is less than that of the first waveguide. Equipped with, The first coupling portion of the first waveguide and the second coupling portion of the second waveguide form a first coupling structure, and the first coupling structure is configured to realize optical coupling between the first waveguide and the second waveguide. A third waveguide in the insulating layer, wherein the third waveguide is located on the side of the second waveguide away from the substrate, the electro-optic modulation efficiency of the third waveguide is higher than that of the first waveguide, and the third coupling portion of the first waveguide and the fourth coupling portion of the third waveguide form a second coupling structure configured to realize optical coupling between the first waveguide and the third waveguide. A chip that further enhances this feature.

4. A substrate and An insulating layer located on one side of the aforementioned substrate, A first waveguide and a second waveguide located within the insulating layer, wherein the second waveguide is located on the side of the first waveguide away from the substrate, the first waveguide has an electro-optic effect, and the transmission loss of the second waveguide is less than that of the first waveguide. Equipped with, The first coupling portion of the first waveguide and the second coupling portion of the second waveguide form a first coupling structure, and the first coupling structure is configured to realize optical coupling between the first waveguide and the second waveguide. A third waveguide in the insulating layer, wherein the third waveguide is located on the side of the second waveguide away from the substrate, the electro-optic modulation efficiency of the third waveguide is higher than that of the first waveguide, and the fifth coupling portion of the first waveguide, the sixth coupling portion of the second waveguide, and the seventh coupling portion of the third waveguide form a third coupling structure, the third coupling structure is configured to realize optical coupling between the second waveguide and the third waveguide. It also has, It's a tip, The aforementioned chip is a single chip.

5. A substrate and An insulating layer located on one side of the aforementioned substrate, A first waveguide and a second waveguide located within the insulating layer, wherein the second waveguide is located on the side of the first waveguide away from the substrate, the first waveguide has an electro-optic effect, and the transmission loss of the second waveguide is less than that of the first waveguide. Equipped with, The first coupling portion of the first waveguide and the second coupling portion of the second waveguide form a first coupling structure, and the first coupling structure is configured to realize optical coupling between the first waveguide and the second waveguide. The third waveguide in the insulating layer further comprises a third waveguide located on the side of the second waveguide away from the substrate. It's a tip, The aforementioned chip is a single chip, A chip in which the material of the third waveguide is lithium niobate, indium phosphide, or tantalum niobate.

6. The first electrode pair located on both sides of the third waveguide in the insulating layer A chip according to any one of claims 1 to 5, further comprising the above.

7. The chip according to any one of claims 1 to 6, wherein the thickness range of the insulating layer between the second waveguide and the third waveguide is [200 nm, 550 nm].

8. A substrate and An insulating layer located on one side of the aforementioned substrate, A first waveguide and a second waveguide located within the insulating layer, wherein the second waveguide is located on the side of the first waveguide away from the substrate, the first waveguide has an electro-optic effect, and the transmission loss of the second waveguide is less than that of the first waveguide. Equipped with, The first coupling portion of the first waveguide and the second coupling portion of the second waveguide form a first coupling structure, and the first coupling structure is configured to realize optical coupling between the first waveguide and the second waveguide. A third waveguide within the insulating layer, the third waveguide located on the side of the second waveguide away from the substrate, A photoelectric detector in the insulating layer, wherein the photoelectric detector is connected to an interlayer interconnection structure using a doping structure, the doping structure is a semiconductor layer having doping elements, the material of the semiconductor layer matches the material of the first waveguide, and the distance between the doping structure and the substrate matches the distance between the first waveguide and the substrate. It also has, It's a tip, The aforementioned chip is a single chip.

9. The chip according to claim 8, wherein the distance between the surface of the photoelectric detector away from the substrate and the surface of the substrate is smaller than the distance between the surface of the second waveguide away from the substrate and the surface of the substrate.

10. The chip according to claim 9, wherein the size range of the photoelectric detector in a direction perpendicular to the surface of the substrate is [200 nm, 350 nm].

11. The second electrode pair located on both sides of the first waveguide in the insulating layer A chip according to any one of claims 1 to 10, further comprising the above.

12. The chip according to any one of claims 1 to 11, wherein the material of the second waveguide is silicon nitride, and the hydrogen content in the silicon nitride material of the second waveguide is 10% or less.

13. The chip according to any one of claims 1 to 12, wherein the transmission loss of the second waveguide is 0.5 dB / cm or less.

14. The chip according to any one of claims 1 to 13, wherein the size range of the second waveguide in a direction perpendicular to the surface of the substrate is [300 nm, 400 nm].

15. An optical communication device comprising the chip described in any one of claims 1 to 14.

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