Optical chip and related equipment
By adopting a vertical PIN structure in the photodetector, the problems of high accuracy requirements and high cost caused by the preparation of different regions on the same silicon layer in the prior art are solved, and the effect of reducing preparation difficulty and cost, improving product yield and photoelectric detection sensitivity is achieved.
Patent Information
- Application Number
- CN202311483355.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-08
- Publication Date
- 2025-05-13
AI Technical Summary
During the preparation process, existing photodetectors need to prepare different areas on the same silicon layer, resulting in high accuracy requirements for production equipment, low product yield and high production cost.
Using a vertical PIN structure, the PIN photodiode is formed by a first silicon structure, a germanium structure and a second silicon structure arranged in sequence along the first direction, so that different regions are prepared multiple times on the same layer and the accuracy requirements for production equipment are reduced.
It reduces the difficulty and cost of preparation, improves product yield, and improves the sensitivity of photoelectric detection.
Smart Images
Figure CN119997673A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application relate to the field of optical communications, and in particular, to an optical chip and related equipment. Background Art
[0002] In optical communication networks, photodetectors are used to convert optical signals into electrical signals.
[0003] A photodetector structure is a germanium detector with a PIN structure. The structure includes a P region, an I region and an N region on a silicon layer, and the three regions are made of different materials. The P region, the I region and the N region form a PIN diode structure, which can realize the conversion of optical signals into electrical signals.
[0004] However, this structure requires the preparation of different regions (the above-mentioned P region, I region and N region) on the same silicon layer. The preparation of this structure requires the preparation of each region in sequence. Before the preparation of the next region, the previous region needs to be patterned and aligned with high precision (that is, the shape and position of the previous region on the silicon layer are obtained, and the accuracy of the shape and position is required to be high). In order to ensure the performance of the photodetector, the position accuracy between different regions is required to be high, resulting in high precision requirements for production equipment, low product yield, and high preparation cost. Summary of the invention
[0005] The embodiments of the present application provide an optical chip and related equipment, which reduce the difficulty of production through a vertical PIN structure.
[0006] In a first aspect, an embodiment of the present application provides an optical chip. The optical chip includes: a substrate layer, a photodetection structure and a first waveguide. The direction from the substrate layer to the photodetection structure is the first direction. The photodetection structure includes a first silicon structure, a germanium structure and a second silicon structure arranged in sequence along the first direction, and the first silicon structure, the germanium structure and the second silicon structure are on different layers in the first direction. The germanium structure extends along a second direction perpendicular to the first direction. The first silicon structure and the second silicon structure are doped silicon of different polarities, and the first silicon structure, the germanium structure and the second silicon structure constitute a PIN photodiode. The first waveguide is located between the substrate layer and the layer where the germanium structure is located. The first waveguide is used to guide the optical signal to be transmitted in the PIN photodiode along the second direction. The PIN photodiode is used to convert the input optical signal of the optical chip into an output electrical signal.
[0007] In the embodiment of the present application, the direction from the substrate layer to the PIN photodiode is defined as the first direction. In the optical chip structure provided in the embodiment of the present application, the PIN photodiode is replaced by a vertical PIN structure arranged along the first direction (that is, each region in the PIN photodiode is arranged on a different layer perpendicular to the surface of the substrate layer) by a traditional horizontal PIN structure arranged horizontally on the same silicon layer (that is, each region in the PIN photodiode is arranged on the same layer parallel to the surface of the substrate layer). Different regions in the PIN photodiode are prepared in different layers, and there is no need to prepare different regions on the same layer multiple times in succession. Compared with ensuring the position accuracy in the horizontal direction between multiple regions on the same layer, it is less difficult to achieve high position accuracy in the vertical direction between different layers. Therefore, the vertical PIN structure can reduce the precision requirements for production equipment, thereby reducing the difficulty of preparation, reducing costs, and improving product yield.
[0008] Moreover, the transmission direction of the input optical signal in the PIN photodiode is the same as the extension direction of the germanium structure, the overlapping distance of the input optical signal and the PIN photodiode is longer, and the absorption efficiency of the germanium structure is higher, which can improve the sensitivity of photoelectric detection. In summary, the optical chip structure provided in the embodiment of the present application can have the advantages of low precision requirements and high detection efficiency, and can ensure the sensitivity of photoelectric detection while having a high product yield.
[0009] In an optional implementation, the first waveguide is located between the substrate layer and the layer where the first silicon structure is located, or on the same layer as the first silicon structure. The first waveguide is used for optical coupling with the PIN photodiode. The first waveguide region is used for coupling an input optical signal to the PIN photodiode.
[0010] In an embodiment of the present application, the photodetection structure and the first waveguide are usually connected by a bonding process. In a vertical PIN structure, the layer where the first silicon structure is located only includes one region in the PIN structure, and does not include other regions of the PIN structure (for example, if the first silicon structure is a P region, then the layer only includes a P region, and does not include an N region and an I region). During bonding, the device structure (each layer only contains one material) has not yet been formed in the PIN layer (i.e., the layer where the photodetection structure 3200 is located), and there is no pattern of the device structure in the horizontal direction, so the alignment accuracy requirement during the bonding process is low. Compared with the horizontal PIN structure, the waveguide region must be aligned to one of the three regions in the PIN structure (for example, the I region) during bonding. The vertical PIN structure provided in the embodiment of the present application has a lower requirement for accuracy during the bonding process, which can reduce the difficulty of production and improve the yield. In addition, the first waveguide and the PIN structure are on different layers, and the material of the first waveguide is not limited by the PIN structure (for example, the PIN structure is composed of a semiconductor material, and the first waveguide can be a non-semiconductor material), and the material selection of the first waveguide is more flexible.
[0011] In an optional implementation, the first waveguide extends along the second direction, and the input optical signal is also transmitted along the second direction on the first waveguide. Along the second direction, the first waveguide, the first silicon structure and the germanium structure are distributed in a step-like manner.
[0012] In an optional implementation, the first waveguide extends along the second direction, and the input optical signal is transmitted along the second direction on the first waveguide. Along the second direction, the first waveguide, the first silicon structure and the germanium structure are distributed in a step-like manner.
[0013] In the embodiment of the present application, the input optical signal is coupled obliquely upward from the first waveguide to the first silicon structure, and then coupled obliquely upward to the germanium structure. The germanium structure is used to absorb the input optical signal and realize the conversion of the optical signal to the electrical signal. The advantage of such coupling is that the absorption of the optical signal by germanium during the coupling process can be reduced, thereby improving the coupling efficiency.
[0014] In an optional implementation, the first waveguide and the first silicon structure are on the same layer, and the first silicon structure is located in the second direction of the first waveguide. The first waveguide is optically coupled to the PIN photodiode, and the first waveguide is used to couple the input optical signal to the PIN photodiode.
[0015] In the embodiment of the present application, the first waveguide and the first silicon structure are on the same layer, so that the coupling efficiency of the input optical signal from the first waveguide to the PIN structure is higher. In addition, since the first waveguide and the first silicon structure are on the same layer, the first waveguide and the first silicon structure can be made of the same material, and the first waveguide and the first silicon structure can be obtained by patterning the material layer, and the processing technology is simple.
[0016] In an optional implementation, the first waveguide is used to: optically couple with the second silicon layer; or optically couple with the germanium layer.
[0017] In an embodiment of the present application, if the first silicon structure is relatively thick (for example, the thickness is greater than 100nm), the first waveguide can be optically coupled with the first silicon structure, and the first silicon structure is optically coupled with the germanium structure. The input optical signal is optically coupled from the first waveguide to the first silicon structure once, and then optically coupled from the first silicon structure to the germanium structure twice, and then enters the germanium structure and is absorbed by the germanium structure. If the first silicon structure is relatively thin (for example, the thickness is less than 100nm), the first waveguide can be directly optically coupled with the germanium structure, and the present application does not limit this.
[0018] In an optional implementation, the optical chip further includes a first electrode and a second electrode. The first electrode is in a first direction of the first silicon structure and connected to the first silicon structure, and the second electrode is in a first direction of the second silicon structure and connected to the second silicon structure. The first electrode and the second electrode are used to transmit output electrical signals.
[0019] As mentioned above, the direction from the substrate layer to the photodetection structure is the first direction, and the first silicon structure is part of the photodetection structure, so the first electrode is located on the side of the first silicon structure away from the substrate layer, and the second electrode is located on the side of the second silicon structure away from the substrate layer.
[0020] In the embodiment of the present application, the first electrode is in the first direction of the first silicon structure, and the second electrode is in the first direction of the second silicon structure. On the one hand, this arrangement makes the distance between the electrode and the silicon structure small, which can reduce the resistance. On the other hand, the preparation of the optical chip is usually prepared from the substrate layer to the top layer (i.e., prepared along the first direction), so that the electrode is in the first direction (above) of the corresponding silicon structure, the processing technology is simpler, and the preparation difficulty is low.
[0021] In an optional implementation, the optical chip further includes a modulator, and the modulator includes a third electrode, a fourth electrode, and a modulator waveguide. The modulator waveguide is on the same layer as the first waveguide and on different regions of the same layer. The third electrode and the fourth electrode are used to apply an input electrical signal of the optical chip to the modulator waveguide. The modulator waveguide is used to modulate the continuous light source based on the input electrical signal to obtain an output optical signal of the optical chip.
[0022] In the embodiment of the present application, different waveguide regions (first waveguide and modulator waveguide) on the same layer are used to achieve optical coupling between the photodetection structure and the modulator, thereby achieving integration of the receiving end and the transmitting end. Integrating the receiving end with the transmitting end can improve the integration level and reduce the size of the device.
[0023] In an embodiment of the present application, the preparation of the photoelectric detection structure requires a high-temperature epitaxial growth process. The modulator waveguide and the first waveguide are prepared on the same layer (the layer is referred to as the waveguide layer in the embodiment of the present application) on the same substrate (substrate layer), and the layers of the photoelectric detection structure are prepared on another substrate. After the preparation of each layer of the photodetector is completed, it is bonded to the waveguide layer, and then the substrate is removed. The waveguide layer material (which is also the material of the modulator waveguide) is not affected by the high-temperature preparation environment during the preparation of the photoelectric detection structure, and the selection of the waveguide layer material (the material of the modulator waveguide and the first waveguide) is more flexible. In addition, the high-speed modulator waveguide has restrictions on the material of the substrate layer (for example, the substrate material needs to be a low dielectric constant material). The photoelectric detection structure can be prepared on any substrate by the above-mentioned method of bonding after processing separately, and the selection of substrate materials is more flexible. For example, a substrate material with a low dielectric constant can be selected to improve the high-frequency performance of the modulator.
[0024] In an optional implementation, the optical chip further includes a reflection unit. The reflection unit is located in the second direction of the photoelectric detection structure. The reflection unit is used to reflect the optical signal (input optical signal) passing through the photoelectric detection structure in the second direction.
[0025] In the embodiment of the present application, the input light signal that is not absorbed by the germanium structure is reflected by the reflection unit, and the reflected light signal is absorbed by the germanium structure, which is equivalent to lengthening the absorption length of the germanium structure, thereby improving the conversion rate of the input light signal and the responsiveness of the photoelectric detection structure.
[0026] In an optional implementation, the reflection unit is located on the layer where the first silicon structure is located, and in the second direction of the first silicon structure; or, the reflection unit is located on the layer where the first waveguide is located, and in the second direction of the photodetector; or, the reflection unit is located on the layer where the first silicon structure is located and the layer where the first waveguide is located (the reflection unit spans two layers), and in the second direction of the photodetector.
[0027] In an optional implementation, the reflection unit includes: a Bragg grating waveguide; or a 1*2 optical splitter and a second waveguide. In the 1*2 optical splitter, the two branch ports are located in the second direction of the combined port, the second waveguide is located in the second direction of the 1*2 optical splitter, and the second waveguide is used to connect the two branch ports.
[0028] In the embodiment of the present application, the 1*2 beam splitter and the second waveguide structure have higher reflection efficiency, which can make the insertion loss of the photoelectric detection structure smaller and the spectral range wider. As mentioned above, the reflection unit can be prepared on the layer where the first silicon structure is located, or on the layer where the first waveguide is located, or across two layers. Specifically, during the processing, the reflection unit can be obtained by etching one or two layers of material (in the layer where the first silicon structure is located and the layer where the first waveguide is located).
[0029] In an optional implementation, the second electrode includes a bending region, and the bending region constitutes an inductor structure.
[0030] In the embodiment of the present application, the inductor structure formed by the bending area can increase the impedance inside the optical chip to achieve matching between the optical chip and the external circuit, thereby improving the transmission efficiency of the output electrical signal and improving the response bandwidth.
[0031] In an optional implementation, the material of the first silicon structure is P-type doped silicon, and the material of the second silicon structure is N-type doped silicon; or, the material of the first silicon structure is N-type doped silicon, and the material of the second silicon structure is P-type doped silicon.
[0032] In the embodiment of the present application, the photodetection structure constitutes a PD structure, which can achieve a higher bandwidth.
[0033] In an optional implementation, the photodetection structure constitutes an avalanche photodiode APD structure. Specifically:
[0034] The material of the first silicon structure is P+-doped silicon, the second silicon structure includes a first substructure, a second substructure and a third substructure arranged in sequence along the first direction, the material of the first substructure is P-type doped silicon, the material of the second substructure is intrinsic silicon, the material of the third substructure is N-type doped silicon, and the first silicon structure, the germanium structure, the first substructure, the second substructure and the third substructure constitute an avalanche photodiode APD structure. Or,
[0035] The first silicon structure includes a first substructure, a second substructure and a third substructure arranged in sequence along a first direction, the material of the first substructure is N-type doped silicon, the material of the second substructure is intrinsic silicon, the material of the third substructure is P-type doped silicon, the material of the second silicon structure is P+ type doped silicon, and the first substructure, the second substructure, the third substructure, the germanium layer and the second silicon structure constitute an avalanche photodiode APD structure.
[0036] In the embodiment of the present application, the photodetection structure constitutes a SCAM APD structure, which can achieve higher responsiveness.
[0037] In an optional implementation, the material of the waveguide layer includes at least one of the following: lithium niobate, silicon, and silicon nitride.
[0038] In a second aspect, an embodiment of the present application provides an optical module, wherein the optical module comprises the optical chip described in the first aspect, wherein a PIN photodiode in the optical chip is used to detect an input optical signal of the optical module.
[0039] In a third aspect, an embodiment of the present application provides an optical module. The optical module includes the optical chip described in the first aspect. The optical module also includes a laser. The laser is optically coupled to the modulator waveguide of the optical chip to provide a continuous light source for the modulator waveguide.
[0040] In a fourth aspect, an embodiment of the present application provides an optical communication device, comprising the optical module described in the second aspect or the third aspect.
[0041] The beneficial effects of the second to fourth aspects refer to the first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Figure 1 A schematic diagram of the structure of the optical chip provided in this application;
[0043] Figure 2 A schematic diagram of the structure of the optical module provided in the embodiment of the present application;
[0044] Figure 3 A schematic diagram of the structure of an optical chip provided in an embodiment of the present application;
[0045] Figure 4A schematic diagram of the structure of an optical module in which a first waveguide and a first silicon structure are on the same layer as provided in an embodiment of the present application;
[0046] Figure 5 A top view of the optical module provided in an embodiment of the present application;
[0047] Figure 6 A side view of an optical module provided in an embodiment of the present application;
[0048] Figure 7 A schematic diagram of the structure of an optical module including a reflective unit provided in an embodiment of the present application;
[0049] Figure 8 A schematic diagram of the structure of a reflection unit provided in an embodiment of the present application;
[0050] Fig. 9 Another schematic diagram of the structure of the reflection unit provided in the embodiment of the present application;
[0051] Fig.10 A schematic diagram of the structure of an optical module including a bending area provided in an embodiment of the present application;
[0052] Fig.11 A schematic diagram of the structure of an optical module including an APD provided in an embodiment of the present application;
[0053] Fig.12 A schematic diagram of the structure of a transceiver-integrated optical module provided in an embodiment of the present application;
[0054] Fig.13 Another structural schematic diagram of the transceiver-integrated optical module provided in an embodiment of the present application. DETAILED DESCRIPTION
[0055] The embodiments of the present application are described below in conjunction with the accompanying drawings. Those skilled in the art will appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.
[0056] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged in appropriate circumstances, which is only to describe the distinction mode adopted by the objects of the same attribute in the embodiments of the present application when describing. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment containing a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment. In addition, "at least one" refers to one or more, and "multiple" refers to two or more. "And / or", describes the association relationship of associated objects, indicating that three relationships can exist, for example, A and / or B, can represent: A exists alone, A and B exist simultaneously, and B exists alone, wherein A, B can be singular or plural. The character " / " generally represents that the associated objects before and after are a kind of "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or plural.
[0057] Photodetectors are a common device in the field of optical communications, used to detect optical signals. With the development of optical communication technology, the rate of optical communication is getting higher and higher, and the rate requirements for photodetectors are also increasing. A high-speed photodetector is a germanium detector with a PIN structure. Figure 1 As shown, the PIN structure photodetector includes a substrate, a P region, an I region and an N region. The material of the I region is germanium.
[0058] The preparation method of the photodetector is as follows: a single crystal silicon layer is obtained on a substrate, and then single crystal germanium, P-doped polycrystalline silicon and N-doped polycrystalline silicon are prepared on the single crystal silicon layer. Among them, the P-doped polycrystalline silicon is the P region, the single crystal germanium is the I region, and the N-doped polycrystalline silicon is the N region. The P region, the I region and the N region constitute a PIN diode structure, which can realize the conversion of optical signals into electrical signals.
[0059] This structure requires the preparation of different regions (the aforementioned P region, I region, and N region) on the same single crystal silicon layer, and the preparation of different regions is carried out in sequence, that is, the preparation of the next region is carried out after the preparation of the previous region is completed. Before the preparation of the next region, the prepared previous region needs to be patterned and aligned with high precision. That is, the shape and position of the previous region on the silicon layer are obtained, and the accuracy of the shape and position is required to be high.
[0060] Since the size deviation of each area in the PIN structure will lead to a large performance loss, the position accuracy between different areas prepared on the single crystal silicon layer is required to be high during the preparation of the photodetector. The high position accuracy requirement leads to the high precision requirement of the production equipment for the photodetector structure, low product yield and high preparation cost.
[0061] In order to solve the above problems, an embodiment of the present application provides an optical chip. The optical chip replaces the horizontal PIN structure with a vertical PIN structure, thereby avoiding the preparation of different regions on the same silicon layer and reducing the difficulty of production.
[0062] The optical chip provided in the embodiment of the present application can be applied in Figure 2 In the optical module shown in FIG. Figure 2 As shown, the optical module includes an electrical chip and an optical chip. The electrical chip includes a signal processing unit, a driver, a transimpedance amplifier, a laser, etc. The optical chip includes a modulator 2100 and a detector 2200.
[0063] In the transmission direction of the optical signal, the signal processing unit processes the electrical signal and inputs the processed electrical signal to the driver. The driver amplifies the electrical signal output by the signal processing unit and inputs it into the modulator as a driving signal, which is also the input signal of the modulator 2100. The laser provides a continuous light source for the modulator 2100, and the modulator 2100 modulates the continuous light source based on the driving signal to obtain an optical signal output.
[0064] In the receiving direction of the optical signal, the detector 2200 receives the input optical signal and converts it into a current signal. The current signal is converted into a voltage signal in the transimpedance amplifier and then input into the signal processing unit for processing (such as dispersion compensation) to obtain an electrical signal output.
[0065] Optionally, the modulator 2100 and the detector 2200 may be Figure 2 As shown, they are integrated on the same optical chip, or they can be respectively arranged on two optical chips, which is not limited in this application. If the modulator 2100 and the detector 2200 are arranged on two optical chips, the optical chip including the modulator 2100 is called the transmitting optical chip, and the optical chip including the detector 2200 is called the receiving optical chip.
[0066] Optional, if Figure 2 The optical module shown is a high-speed optical communication module, and the optical module can be applied to high-speed coherent optical transmission, metropolitan optical communication, short-distance interconnection system and other scenarios. In the high-speed communication scenario, the signal processing unit is used to realize high-speed processing of electrical signals.
[0067] like Figure 3As shown, the optical chip 3000 provided in the embodiment of the present application includes: a substrate layer 3100, a photoelectric detection structure 3200, and a first waveguide 3300. The optical chip 3000 may be a receiving optical chip for realizing the conversion of optical signals into electrical signals.
[0068] The direction from the substrate layer 3100 to the photodetection structure 3200 is a first direction (eg Figure 3 The photodetection structure 3200 includes a first silicon structure 3210, a germanium structure 3220, and a second silicon structure 3230 arranged in sequence along a first direction. The first silicon structure 3210, the germanium structure 3220, and the second silicon structure 3230 are on different layers in the first direction. The germanium structure 3220 is arranged along a second direction (e.g., perpendicular to the first direction) Figure 3 The direction in which the longitudinal axis extends is perpendicular to the paper plane and inward.
[0069] The first silicon structure 3210, the germanium structure 3220 and the second silicon structure 3230 in the photodetection structure 3200 constitute a PIN photodiode. Therefore, the photodetection structure 3200 is also a PIN photodiode.
[0070] The first waveguide 3300 is located between the substrate layer 3100 and the layer where the first silicon structure 3210 is located, or on the same layer as the first silicon structure 3210. The first waveguide 3300 is used to guide the optical signal to be transmitted along the second direction in the photodetection structure 3200 (PIN photodiode). That is, the optical signal is transmitted along the extension direction of the germanium structure 3220 in the photodetection structure 3200 (PIN photodiode).
[0071] The photodetection structure 3200 (PIN photodiode) is used to convert the input optical signal of the optical chip 3000 into an output electrical signal.
[0072] In an embodiment of the present application, the PIN photodiode is replaced by a traditional horizontal PIN structure arranged horizontally on the same silicon layer (that is, each region in the PIN photodiode is arranged on the same layer parallel to the surface of the substrate layer) with a vertical PIN structure arranged along a first direction (that is, each region in the PIN photodiode is arranged on a different layer perpendicular to the surface of the substrate layer). Different regions in the PIN photodiode are prepared in different layers, and there is no need to prepare different regions multiple times on the same layer. Compared with ensuring the position accuracy in the horizontal direction between multiple regions on the same layer, it is less difficult to achieve high position accuracy in the vertical direction between different layers. Therefore, the vertical PIN structure can reduce the precision requirements for production equipment, thereby reducing the difficulty of preparation, reducing costs, and improving product yield.
[0073] Moreover, the transmission direction of the input light signal in the PIN photodiode is the same as the extension direction of the germanium structure 3220 , the overlapping effective distance of the input light signal and the PIN photodiode is longer, and the absorption efficiency of the germanium structure 3220 is higher, which can improve the sensitivity of photoelectric detection.
[0074] In summary, the optical chip 3000 structure provided in the embodiment of the present application can have the advantages of both low precision requirements and high detection efficiency, and can ensure the sensitivity of photoelectric detection while having a high product yield.
[0075] Optionally, if the material of the first silicon structure 3210 is P-type doped silicon, the material of the second silicon structure 3230 is N-type doped silicon. Optionally, if the material of the first silicon structure 3210 is N-type doped silicon, the material of the second silicon structure 3230 is P-type doped silicon.
[0076] Optionally, other layers, such as a buried oxide (BOX) layer (also called a buried layer), may be included between the substrate layer 3100 and the first waveguide 3300, which is not limited in the present application.
[0077] In an optional implementation, the material of the substrate layer 3100 is silicon or quartz, and the optical chip 3000 includes a buried layer. In an optional implementation, the substrate layer 3100 is a quartz substrate, and the optical chip 3000 does not include a buried layer.
[0078] Optional, such as Figure 3 As shown, the optical chip 3000 may further include a first electrode 3400 and a second electrode 3500. The first electrode 3400 is in a first direction of the first silicon structure 3210 and is connected to the first silicon structure 3210. The second electrode 3500 is in a first direction of the second silicon structure 3230 and is connected to the second silicon structure 3230. The first electrode 3300 and the second electrode 3400 are used to transmit the output electrical signal of the optical chip 3000.
[0079] Optionally, the first electrode 3400 and the second electrode 3500 may be located on a surface of the optical chip 3000. Alternatively, the first electrode 3400 and the second electrode 3500 may be buried in silicon oxide and extend outside the photodetection structure 3200, and then exposed to be electrically connected to the outside, which is not limited in the present application.
[0080] Optionally, the first electrode 3400 and the second electrode 3500 can be used to apply a reverse bias voltage to the photodetection structure 3200 and guide the photogenerated carriers to be output, that is, output a current signal that changes with the light signal. Figure 2In the optical module structure shown, the current signal output by the photoelectric detection structure 3200 is used as the input of the transimpedance amplifier and converted into a voltage signal, wherein the reverse bias voltage is a DC quantity and the output electrical signal is an AC quantity.
[0081] In the embodiment of the present application, the number of the first electrodes 3400 is not limited. Figure 3 Two are shown, but there may be more or less, and this application does not limit this.
[0082] If Figure 3 As shown, the two first electrodes 3400 are respectively located on the left and right sides of the photodetection structure 3200, and the two first electrodes 3400 are in parallel relationship in the circuit. This structure can reduce the resistance of the first electrode 3400 and improve the bandwidth of the device.
[0083] In this structure, the second silicon structure 3230 and the germanium structure 3220 have the same or similar patterns (generally etched using the same photolithography pattern, and the second silicon structure 3230 and the germanium structure 3220 in the figure have the same width), and the first silicon structure 3210 is wider than the germanium layer 3220 so that the first silicon structure 3210 can be connected to the first electrode 3400.
[0084] Optionally, the first electrode 3400 may be a G (ground) electrode, and the second electrode 3500 may be an S (signal) electrode, and the first electrode 3400 and the second electrode 3500 may constitute a GSG (ground-signal-ground) electrode structure.
[0085] In the embodiment of the present application, the first silicon structure 3210, the germanium structure 3220 and the second silicon structure 3230 can be grown by an epitaxial growth process. According to the process conditions of the epitaxial growth, there may be a transition layer (buffer layer) between the first silicon structure 3210 and the germanium structure 3220, and between the germanium structure 3220 and the second silicon structure 3230. The transition layer is used to overcome the lattice constant mismatch problem between single crystal germanium (germanium layer 3220) and silicon (first silicon structure 3210 or second silicon structure 3230). Optionally, the transition layer may be germanium or germanium-silicon alloy with high defect density, which is not limited in the present application.
[0086] In the embodiment of the present application, the first waveguide 3300 is located between the substrate layer 3100 and the layer where the germanium structure 3220 is located. In different embodiments, the first waveguide 3300 may be on different layers.
[0087] like Figure 3As shown, in an optional implementation, the first waveguide 3300 is located between the substrate layer 3100 and the layer where the first silicon structure 3210 is located. That is, the first waveguide 3300 is located on a separate layer between the substrate layer 3100 and the first silicon structure 3210. The first waveguide 3310 is used to achieve optical coupling with the PIN photodiode. The input optical signal of the optical chip 3000 is coupled to the PIN photodiode via the first waveguide 3310.
[0088] In an embodiment of the present application, the photodetection structure 3200 is usually connected to the first waveguide 3300 by a bonding process. In the vertical PIN structure, the layer where the first silicon structure 3210 is located only includes one region in the PIN structure, and does not include other regions of the PIN structure (for example, if the first silicon structure 3210 is a P region, then the layer only includes a P region, and does not include an N region and an I region). During bonding, the device structure has not yet been formed in the PIN layer (i.e., the layer where the photodetection structure 3200 is located), and there is no pattern of the device structure in the horizontal direction, so the alignment accuracy requirements during the bonding process are low. Compared to the horizontal PIN structure, the waveguide region must be aligned to one of the three regions in the PIN structure (for example, the I region) during bonding. The vertical PIN structure provided in the embodiment of the present application has lower requirements for accuracy during the bonding process, which can reduce production difficulty and improve yield.
[0089] Furthermore, the first waveguide 3300 and the PIN structure are on different layers, and the material of the first waveguide 3300 is not restricted by the PIN structure (for example, the PIN structure is made of semiconductor material, and the first waveguide 3300 can be made of non-semiconductor material), so the material selection of the first waveguide 3300 is more flexible.
[0090] like Figure 4 As shown, in an optional implementation, the first waveguide 3300 and the first silicon structure 3210 are on the same layer, and the first silicon structure 3210 is located in the second direction of the first waveguide 3300. The first waveguide 3310 is used to achieve optical coupling with the PIN photodiode. The input optical signal of the optical chip 3000 is coupled to the PIN photodiode via the first waveguide 3310.
[0091] In the embodiment of the present application, the first waveguide 3300 and the first silicon structure 3210 are on the same layer, so that the coupling efficiency of the input optical signal from the first waveguide 3300 to the PIN structure is higher. In addition, since the first waveguide 3300 and the first silicon structure 3210 are on the same layer, the first waveguide 3300 and the first silicon structure 3210 can be made of the same material, and the first waveguide 3300 and the first silicon structure 3210 can be obtained by patterning the layer of material, and the processing technology is simple.
[0092] Optionally, if the first silicon structure 3210 is thicker (for example, the thickness is greater than 100 nm), the first waveguide 3300 can be optically coupled with the first silicon structure 3210, and the first silicon structure 3210 is optically coupled with the germanium structure 3220. The input optical signal is optically coupled from the first waveguide 3300 to the first silicon structure 3210, and then optically coupled from the first silicon structure 3210 to the germanium structure 3220, and then enters the germanium structure 3220 and is absorbed by the germanium structure 2320.
[0093] Optionally, if the first silicon structure 3210 is relatively thin (for example, the thickness is less than 100 nm), the first waveguide 3300 may be directly optically coupled to the germanium structure 3220 , which is not limited in the present application.
[0094] It is worth noting that there may be a certain distance between the first waveguide 3300 and the first silicon structure 3210 , and the optical coupling between the first waveguide 3300 and the first silicon structure 3210 may be achieved by evanescent wave coupling, which is not limited in the present application.
[0095] Optionally, other layers may be included between the substrate layer 3100 and the photoelectric detection structure 3200 , which is not limited in the present application.
[0096] In the embodiment of the present application, the extension direction of the germanium structure 3220 is referred to as the second direction, which is also the transmission direction of the input light signal in the photodetection structure 3200. The second direction is perpendicular to the arrangement direction (first direction) of each layer in the photodetection structure 3200 (PIN photodiode). Figure 3 In the structure shown, the second direction is perpendicular to the paper plane and inward. Figure 5 It is a top view of the optical chip 3000 , wherein the extension direction of the first waveguide 3300 (ie, the transmission direction of the input optical signal) is from left to right. Figure 3 The structure shown is Figure 5 Schematic diagram of the structure in mid-section.
[0097] Figure 6 for Figure 5 A side view of the structure shown. Figure 6 As shown, the extension direction (second direction) of the first waveguide 3300 is from left to right, and the input optical signal is also transmitted along the second direction on the first waveguide 3300.
[0098] Optionally, in the second direction, the first waveguide 3300, the first silicon structure 3210 and the germanium structure 3220 may be distributed in a stepped manner. Figure 6 As shown, the second direction is from left to right, and the left edge of the first silicon structure 3210 is located above the first waveguide 3300 , and the left edge of the germanium structure 3220 is located above the first silicon structure 3210 .
[0099] In this structure, the input optical signal is coupled obliquely upward from the first waveguide 3300 to the first silicon structure 3210, and then coupled obliquely upward to the germanium structure 3220. The germanium structure 3220 is used to absorb the input optical signal and realize the conversion of the optical signal to the electrical signal. The advantage of such coupling is that the absorption of the optical signal by germanium during the coupling process can be reduced, thereby improving the coupling efficiency.
[0100] Optionally, in order to facilitate the coupling of the input optical signal from the first waveguide 3300 to the first silicon structure 3210, a special structural design may be performed in the coupling region between the first waveguide 3300 and the first silicon structure 3210. Figure 5 In the top view shown, the right edge of the first waveguide 3300 and the left edge of the first silicon structure 3210 are both tapered taper structures, which can achieve high-efficiency optical coupling.
[0101] Similarly, in order to facilitate the coupling of the input optical signal from the first silicon structure 3210 to the germanium structure 3220, Figure 5 As shown, the left edge of the germanium structure 3220 is a tapered tapered structure, which can achieve high-efficiency optical coupling from the first silicon structure 3210 to the germanium structure 3220 .
[0102] Optionally, in the embodiment of the present application, a reflection unit may be further provided in the second direction of the photodetection structure 3200 to improve the absorption rate of the germanium structure 3220 to the input optical signal. Figure 7 As shown, in the second direction (right side in the figure) of the photoelectric detection structure 3200, a reflection unit 3600 is further included. The reflection unit 3600 is used to reflect the input optical signal in the second direction.
[0103] In the embodiment of the present application, the input optical signal that is not absorbed by the germanium structure 3220 is reflected by the reflection unit 3600, and the reflected optical signal is absorbed by the germanium structure 3220. This is equivalent to lengthening the absorption length of the germanium structure 3220, thereby improving the conversion rate of the input optical signal and improving the responsiveness of the photoelectric detection structure 3200.
[0104] Optionally, the reflection unit 3600 can be on the same layer as the first silicon structure 3210, or on the same layer as the first waveguide 3300, or span two layers (i.e., including both the part on the same layer as the first silicon structure 3210 and the part on the same layer as the first waveguide 3300), which is not limited in the present application.
[0105] Optionally, the reflection unit 3600 may include: Figure 8 The Bragg grating waveguide shown, or including Fig. 9 The 1*2 splitter and the second waveguide are shown.
[0106] exist Fig. 9In the structure shown, the 1*2 optical splitter includes a combining port and two branch ports. The two branch ports are located in the second direction of the combining port, and the second waveguide is located in the second direction of the 1*2 optical splitter. The 1*2 optical splitter is used to split the optical signal in the second direction into two beams of light, and the two beams of light enter different branch ports respectively. The second waveguide is used to connect the two branch ports, and the optical signal from the upper branch port enters the lower branch port through the second waveguide and becomes a beam of light in the opposite direction; the optical signal from the lower branch port enters the upper branch port through the second waveguide and becomes another beam of light in the opposite direction. The two beams of light in the opposite direction are combined by the 1*2 optical splitter and enter the combining port to realize the reflection of the optical signal in the second direction. In this structure, the reflection efficiency is higher, which can make the insertion loss of the photoelectric detection structure 3200 smaller and the spectral range wider.
[0107] Optionally, you can Fig.10 As shown, a bending region is provided on the second electrode 3500, and the bending region can form an inductor structure. The inductor structure formed by the bending region can improve the impedance inside the optical chip to achieve matching between the optical chip 3000 and the external circuit, thereby improving the transmission efficiency of the output electrical signal and improving the response bandwidth.
[0108] Optionally, the second electrode 3500 can be connected to the second silicon structure 3230 through an extended electrode. The extended electrodes are distributed from top to bottom. The extended electrodes can also be part of the inductor structure to achieve matching between the optical chip 3000 and the external circuit, improve the transmission efficiency of the output electrical signal, and improve the bandwidth.
[0109] In the above Figures 3 to 10 In the structure shown, the first silicon structure 3210, the germanium structure 3220 and the second silicon structure 3230 constitute a photodiode (PD) structure. Optionally, in addition to the conventional PD structure, the structures of the first silicon structure 3210 and the second silicon structure 3230 can also be improved so that the photodetection structure 3200 constitutes a separate absorption charge and multiplication avalanche photodiode (SCAM APD).
[0110] like Fig.11As shown, the material of the first silicon structure 3210 may be P+-type doped silicon, and the second silicon layer 3230 may include a first substructure 3231, a second substructure 3232, and a third substructure 3233 arranged in sequence along the first direction. The material of the first substructure 3231 is P-type doped silicon, the material of the second substructure 3232 is intrinsic silicon, and the material of the third substructure 3233 is N-type doped silicon. The first silicon structure 3210, the germanium structure 3220, the first substructure 3231, the second substructure 3232, and the third substructure 3233 together constitute a SCAM APD structure.
[0111] Optionally, the material distribution of each layer inside the SCAM APD structure can also be changed. For example, the first silicon structure 3210 includes a first substructure, a second substructure, and a third substructure arranged in sequence along a first direction. The material of the first substructure is N-type doped silicon, the material of the second substructure is intrinsic silicon, and the material of the third substructure is P-type doped silicon. The material of the second silicon structure 3230 is P+ type doped silicon. The first substructure, the second substructure, the third substructure, the germanium structure 3220, and the second silicon structure 3230 together constitute the SCAM APD structure.
[0112] In the embodiment of the present application, if the photodetection structure 3200 is a SCAM APD structure, a higher responsivity can be achieved. If the photodetection structure 3200 is a PD structure, a higher bandwidth can be achieved.
[0113] Figures 3 to 11 In the embodiment shown, the optical chip 3000 is a receiving optical chip, and the vertical PIN structure (photoelectric detection structure 3200) in the optical chip 3000 is used to realize the conversion of optical signals into electrical signals. Optionally, the vertical PIN structure and the modulation structure can also be made on the same optical chip to realize the integration of the receiving end and the transmitting end. In this structure, the optical chip 3000 is an integrated optical chip for transmitting and receiving.
[0114] like Fig.12 As shown, the optical chip 3000 also includes a modulator, and the modulator includes a third electrode 3700, a fourth electrode 3800, and a modulator waveguide 3900. The modulator waveguide 3900 is on the same layer as the first waveguide 3300, and on a different region of the same layer. The third electrode 3700 and the fourth electrode 3800 are used to apply an input electrical signal of the optical chip 3000 to the modulator waveguide 3900. The modulator waveguide 3900 is used to modulate the continuous light source based on the input electrical signal.
[0115] The modulator waveguide 3900 is part of the interference structure in the modulator, such as Fig.13 The Mach-Zehnder interference structure shown. Optionally, the modulator may further include more electrodes or other interference structures, which is not limited in the present application.
[0116] The third electrode 3700 and the fourth electrode 3800 are located on both sides of the modulator waveguide 3900 and are used to apply an electrical signal to the modulator waveguide 3900 so that the optical signal transmitted by the modulator waveguide 3900 changes with the electrical signal to obtain an output optical signal of the optical chip 3000.
[0117] In the embodiment of the present application, different waveguide regions (first waveguide 3300 and modulator waveguide 3900) on the same layer are used to achieve optical coupling between the photodetection structure 3200 and the modulator, thereby achieving integration of the receiving end and the transmitting end. Integrating the receiving end with the transmitting end can improve the integration level and reduce the size of the device.
[0118] Optionally, the third electrode 3700 and the fourth electrode 3800 may be located on a certain surface (such as the upper surface) of the optical chip 3000. Alternatively, the third electrode 3700 and the fourth electrode 3800 may be buried in silicon oxide and extend outside the modulator waveguide, and then exposed to be electrically connected to the outside, which is not limited in the present application.
[0119] Optional, Fig.12 The structure shown can be fabricated by machining and bonding processes on two substrates, one of which is used to fabricate the first waveguide 3300 and the modulator waveguide 3900 , and the other is used to fabricate the layers in the photodetection structure 3200 .
[0120] Specifically, a layer of waveguide material may be prepared on the substrate layer 3100, and the layer is called a waveguide layer. The first waveguide 3300 and the modulator waveguide 3900 are prepared on the waveguide layer by etching and other processes. Optionally, the material of the waveguide layer may be lithium niobate, silicon, silicon nitride, etc., which is not limited in this application.
[0121] Optionally, in order to achieve high-speed modulation, the substrate layer 3100 may be a substrate with a low dielectric constant (such as a quartz substrate). For the modulator waveguide 3900, a substrate with a low dielectric constant can reduce the microwave loss of the electrical signal during modulation, thereby achieving higher device performance, such as half-wave voltage, bandwidth, etc.
[0122] On another substrate, the materials of each layer in the photoelectric detection structure 3200 (the materials of the layers where the first silicon structure 3210, the germanium structure 3220, and the second silicon structure 3230 are located, the materials of each structure are distributed on the entire layer, and the shapes of each structure are processed in subsequent steps) can be prepared by a high-temperature epitaxial growth process. The multilayer structure is introduced onto the first substrate by bonding. The structure is Fig.12 The structure of the upper middle part is also called the upper structure in the embodiment of the present application.
[0123] Then, the substrate of the upper structure is removed by chemical mechanical polishing (CMP) or etching, and the excess material of each layer structure (first silicon structure 3210, germanium structure 3220, second silicon structure 3230, etc.) in the photoelectric detection structure 3200 is removed by etching, etc., to obtain the shape of each structure (for example, the step shape in the above embodiment). Then, the first electrode 3400, the second electrode 3500, the third electrode 3700 and the fourth electrode 3800 are prepared with the extension structure of the above electrodes to realize the connection between the electrodes and the corresponding structures, and the optical chip 3000 is obtained.
[0124] Optionally, during the process of preparing the upper structure, the redundant materials of each layer in the photoelectric detection structure 3200 may be removed to obtain the shape of each layer. That is, the shape of each layer structure in the photoelectric detection structure 3200 is obtained before bonding.
[0125] In an embodiment of the present application, the preparation of the photodetection structure 3200 requires a high-temperature epitaxial growth process. The modulator waveguide 3900 and the first waveguide 3300 are prepared on the same substrate (substrate layer 3100), and the various layers of the photodetection structure 3200 are prepared on another substrate. After the preparation of each layer of the photodetector 3200 is completed, it is bonded to the waveguide layer (including the first waveguide 3300 and the modulator waveguide 3900), the substrate is removed, and then the various layers of the photodetection structure 3200 are prepared. Then, the waveguide layer material is not affected by the high-temperature preparation environment during the preparation of each layer of the photodetection structure 3200, and the selection of the waveguide layer material is more flexible (that is, the material selection of the modulator waveguide 3900 is more flexible).
[0126] In addition, if high-speed modulation is to be achieved, a specific substrate layer 3100 material needs to be selected (for example, the substrate material needs to be a low dielectric constant material). The photoelectric detection structure 3200 can be prepared on any substrate by the above-mentioned method of separate processing and bonding, and then the substrate on which the photoelectric detection structure 3200 is prepared is removed. After bonding, another part of the substrate is retained. The retained substrate material is not limited by the processing process of the photoelectric detection structure 3200, and the selection of substrate materials is more flexible. For example, a substrate material with a low dielectric constant can be selected to improve the high-frequency performance of the modulator.
[0127] Fig.12 The corresponding top view is as follows Fig.13 As shown. The continuous light source of the modulator waveguide 3900 comes from Figure 2 The transmission direction of the continuous light source can be as follows: Fig.13 The transmission direction shown is the same as the transmission direction (second direction) of the input optical signal, or may be different therefrom, and the present application does not impose any limitation on this.
[0128] The modulator modulates the continuous light source based on the input electrical signal, and the modulated output optical signal is output from the optical chip 3000 via the modulator waveguide 3900. The modulator structure is generally an MZ interferometer structure or a coherent modulator structure composed of multiple MZ interferometers, which is not limited here.
[0129] Will Figures 3 to 13 The optical chip 3000 structure shown is applied in Figure 2 The optical module shown is the optical module provided in the embodiment of the present application. Fig.12 and Fig.13 In the optical chip 3000 shown, the laser in the optical module is optically coupled to the modulator waveguide 3320 in the optical chip 3000 , and the laser is used to provide a continuous light source for the modulator waveguide 3320 .
[0130] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.
[0131] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.
[0132] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
[0133] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.
[0134] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.
Claims
1. An optical chip, characterized in that: include: A substrate layer, a photoelectric detection structure and a first waveguide, wherein the direction from the substrate layer to the photoelectric detection structure is a first direction; The photodetection structure comprises a first silicon structure, a germanium structure, and a second silicon structure arranged in sequence along the first direction, the first silicon structure, the germanium structure, and the second silicon structure are on different layers in the first direction, the germanium structure extends along a second direction perpendicular to the first direction, the first silicon structure and the second silicon structure are doped silicon with different polarities, and the first silicon structure, the germanium structure, and the second silicon structure constitute a PIN photodiode; The first waveguide is located between the substrate layer and the layer where the first silicon structure is located, or is on the same layer as the first silicon structure, and the first waveguide is used to guide the optical signal to be transmitted in the PIN photodiode along the second direction; The PIN photodiode is used to convert the input optical signal of the optical chip into an output electrical signal.
2. The optical chip according to claim 1, characterized in that: The first waveguide is located between the substrate layer and the layer where the first silicon structure is located; The first waveguide is optically coupled to the PIN photodiode, and the first waveguide is used to couple the input optical signal to the PIN photodiode.
3. The optical chip according to claim 2, characterized in that: The first waveguide extends along the second direction, and the input optical signal is transmitted along the second direction on the first waveguide; Along the second direction, the first waveguide, the first silicon structure and the germanium structure are distributed in a stepped manner.
4. The optical chip according to claim 1, characterized in that: The first waveguide and the first silicon structure are on the same layer, and the first silicon structure is located in the second direction of the first waveguide; The first waveguide is optically coupled to the PIN photodiode, and the first waveguide is used to couple the input optical signal to the PIN photodiode.
5. The optical chip according to claims 2 to 4, characterized in that: The first waveguide is used for: optically coupled to the first silicon structure; or, Optically coupled to the germanium structure.
6. The optical chip according to any one of claims 1 to 5, characterized in that: Also includes: a first electrode and a second electrode; The first electrode is in the first direction of the first silicon structure and connected to the first silicon structure, and the second electrode is in the first direction of the second silicon structure and connected to the second silicon structure; The first electrode and the second electrode are used to transmit the output electrical signal.
7. The optical chip according to any one of claims 1 to 6, characterized in that: The optical chip further includes a modulator, wherein the modulator includes: a third electrode, a fourth electrode and a modulator waveguide; The modulator waveguide is on the same layer as the first waveguide and on a different region of the same layer; The third electrode and the fourth electrode are used to apply an input electrical signal of the optical chip to the modulator waveguide; The modulator waveguide is used to modulate a continuous light source based on the input electrical signal to obtain an output optical signal of the optical chip.
8. The optical chip according to claim 7, characterized in that: Also included is a reflection unit; The reflection unit is located in the second direction of the photoelectric detection structure, and the reflection unit is used to reflect the input light signal in the second direction.
9. The optical chip according to claim 8, characterized in that: The reflection unit is located at: on the layer where the first silicon structure is located and in the second direction of the first silicon structure; or, on the layer where the first waveguide is located and in the second direction of the photodetector; or, The first silicon structure is located on a layer and a layer where the first waveguide is located, and is in the second direction of the photodetector.
10. The optical chip according to claim 8 or 9, characterized in that: The reflection unit comprises: Bragg grating waveguide; or, 1*2 optical splitter and second waveguide; In the 1*2 optical splitter, two branch ports are located in the second direction of the multiplexing port, the second waveguide is located in the second direction of the 1*2 optical splitter, and the second waveguide is used to connect the two branch ports.
11. The optical chip according to any one of claims 6 to 10, characterized in that: The second electrode includes a bending region, and the bending region forms an inductor structure.
12. The optical chip according to any one of claims 1 to 11, characterized in that: The material of the first silicon structure is P-type doped silicon, and the material of the second silicon structure is N-type doped silicon; or, The material of the first silicon structure is N-type doped silicon, and the material of the second silicon structure is P-type doped silicon.
13. The optical chip according to any one of claims 1 to 11, characterized in that: The material of the first silicon structure is P+-doped silicon, the second silicon structure includes a first substructure, a second substructure and a third substructure arranged in sequence along the first direction, the material of the first substructure is P-type doped silicon, the material of the second substructure is intrinsic silicon, the material of the third substructure is N-type doped silicon, and the first silicon structure, the germanium structure, the first substructure, the second substructure and the third substructure constitute an avalanche photodiode APD structure; or, The first silicon structure includes a first substructure, a second substructure and a third substructure arranged in sequence along the first direction, the material of the first substructure is N-type doped silicon, the material of the second substructure is intrinsic silicon, the material of the third substructure is P-type doped silicon, the material of the second silicon structure is P+ type doped silicon, and the first substructure, the second substructure, the third substructure, the germanium structure and the second silicon structure constitute an avalanche photodiode APD structure.
14. The optical chip according to any one of claims 1 to 13, characterized in that: The material of the first waveguide includes at least one of the following: Lithium niobate, silicon, silicon nitride.
15. An optical module, characterized in that: The optical chip comprises the optical chip according to any one of claims 1 to 14, wherein the PIN photodiode in the optical chip is used to detect the input optical signal of the optical module.
16. An optical module, characterized in that: The optical chip comprising any one of claims 7 to 14, wherein the optical module further comprises a laser; The laser is optically coupled to the modulator waveguide of the optical chip to provide a continuous light source for the modulator waveguide.
17. An optical communication device, characterized in that: Includes the optical module according to claim 15 or 16.